fuse.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
 
  Implementation of the high-level FUSE API on top of the low-level
  API.
 
  This program can be distributed under the terms of the GNU LGPLv2.
  See the file LGPL2.txt
*/
 
#define _GNU_SOURCE
#include "fuse.h"
#include <pthread.h>
 
#include "fuse_config.h"
#include "fuse_i.h"
#include "fuse_lowlevel.h"
#include "fuse_opt.h"
#include "fuse_misc.h"
#include "fuse_kernel.h"
#include "util.h"
 
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdbool.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <limits.h>
#include <errno.h>
#include <signal.h>
#include <dlfcn.h>
#include <assert.h>
#include <poll.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/file.h>
 
#define FUSE_NODE_SLAB 1
 
#ifndef MAP_ANONYMOUS
#undef FUSE_NODE_SLAB
#endif
 
#ifndef RENAME_EXCHANGE
#define RENAME_EXCHANGE         (1 << 1)        /* Exchange source and dest */
#endif
 
#define FUSE_DEFAULT_INTR_SIGNAL SIGUSR1
 
#define FUSE_UNKNOWN_INO 0xffffffff
#define OFFSET_MAX 0x7fffffffffffffffLL
 
#define NODE_TABLE_MIN_SIZE 8192
 
struct fuse_fs {
        struct fuse_operations op;
        void *user_data;
        int debug;
};
 
struct fusemod_so {
        void *handle;
        int ctr;
};
 
struct lock_queue_element {
        struct lock_queue_element *next;
        pthread_cond_t cond;
        fuse_ino_t nodeid1;
        const char *name1;
        char **path1;
        struct node **wnode1;
        fuse_ino_t nodeid2;
        const char *name2;
        char **path2;
        struct node **wnode2;
        int err;
        bool done : 1;
};
 
struct node_table {
        struct node **array;
        size_t use;
        size_t size;
        size_t split;
};
 
#define list_entry(ptr, type, member)           \
        container_of(ptr, type, member)
 
struct list_head {
        struct list_head *next;
        struct list_head *prev;
};
 
struct node_slab {
        struct list_head list;  /* must be the first member */
        struct list_head freelist;
        int used;
};
 
struct fuse {
        struct fuse_session *se;
        struct node_table name_table;
        struct node_table id_table;
        struct list_head lru_table;
        fuse_ino_t ctr;
        unsigned int generation;
        unsigned int hidectr;
        pthread_mutex_t lock;
        struct fuse_config conf;
        int intr_installed;
        struct fuse_fs *fs;
        struct lock_queue_element *lockq;
        int pagesize;
        struct list_head partial_slabs;
        struct list_head full_slabs;
        pthread_t prune_thread;
};
 
struct lock {
        int type;
        off_t start;
        off_t end;
        pid_t pid;
        uint64_t owner;
        struct lock *next;
};
 
struct node {
        struct node *name_next;
        struct node *id_next;
        fuse_ino_t nodeid;
        unsigned int generation;
        int refctr;
        struct node *parent;
        char *name;
        uint64_t nlookup;
        int open_count;
        struct timespec stat_updated;
        struct timespec mtime;
        off_t size;
        struct lock *locks;
        unsigned int is_hidden : 1;
        unsigned int cache_valid : 1;
        int treelock;
        char inline_name[32];
};
 
#define TREELOCK_WRITE -1
#define TREELOCK_WAIT_OFFSET INT_MIN
 
struct node_lru {
        struct node node;
        struct list_head lru;
        struct timespec forget_time;
};
 
struct fuse_direntry {
        struct stat stat;
        enum fuse_fill_dir_flags flags;
        char *name;
        struct fuse_direntry *next;
};
 
struct fuse_dh {
        pthread_mutex_t lock;
        struct fuse *fuse;
        fuse_req_t req;
        char *contents;
        struct fuse_direntry *first;
        struct fuse_direntry **last;
        unsigned len;
        unsigned size;
        unsigned needlen;
        int filled;
        uint64_t fh;
        int error;
        fuse_ino_t nodeid;
};
 
struct fuse_context_i {
        struct fuse_context ctx;
        fuse_req_t req;
};
 
/* Defined by FUSE_REGISTER_MODULE() in lib/modules/subdir.c and iconv.c.  */
extern fuse_module_factory_t fuse_module_subdir_factory;
#ifdef HAVE_ICONV
extern fuse_module_factory_t fuse_module_iconv_factory;
#endif
 
static pthread_key_t fuse_context_key;
static pthread_mutex_t fuse_context_lock = PTHREAD_MUTEX_INITIALIZER;
static int fuse_context_ref;
static struct fuse_module *fuse_modules = NULL;
 
static int fuse_register_module(const char *name,
                                fuse_module_factory_t factory,
                                struct fusemod_so *so)
{
        struct fuse_module *mod;
 
        mod = calloc(1, sizeof(struct fuse_module));
        if (!mod) {
                fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate module\n");
                return -1;
        }
        mod->name = strdup(name);
        if (!mod->name) {
                fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate module name\n");
                free(mod);
                return -1;
        }
        mod->factory = factory;
        mod->ctr = 0;
        mod->so = so;
        if (mod->so)
                mod->so->ctr++;
        mod->next = fuse_modules;
        fuse_modules = mod;
 
        return 0;
}
 
static void fuse_unregister_module(struct fuse_module *m)
{
        struct fuse_module **mp;
        for (mp = &fuse_modules; *mp; mp = &(*mp)->next) {
                if (*mp == m) {
                        *mp = (*mp)->next;
                        break;
                }
        }
        free(m->name);
        free(m);
}
 
static int fuse_load_so_module(const char *module)
{
        int ret = -1;
        char *tmp;
        struct fusemod_so *so;
        fuse_module_factory_t *factory;
 
        tmp = malloc(strlen(module) + 64);
        if (!tmp) {
                fuse_log(FUSE_LOG_ERR, "fuse: memory allocation failed\n");
                return -1;
        }
        sprintf(tmp, "libfusemod_%s.so", module);
        so = calloc(1, sizeof(struct fusemod_so));
        if (!so) {
                fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate module so\n");
                goto out;
        }
 
        so->handle = dlopen(tmp, RTLD_NOW);
        if (so->handle == NULL) {
                fuse_log(FUSE_LOG_ERR, "fuse: dlopen(%s) failed: %s\n",
                        tmp, dlerror());
                goto out_free_so;
        }
 
        sprintf(tmp, "fuse_module_%s_factory", module);
        factory = (fuse_module_factory_t*)dlsym(so->handle, tmp);
        if (factory == NULL) {
                fuse_log(FUSE_LOG_ERR, "fuse: symbol <%s> not found in module: %s\n",
                        tmp, dlerror());
                goto out_dlclose;
        }
        ret = fuse_register_module(module, *factory, so);
        if (ret)
                goto out_dlclose;
 
out:
        free(tmp);
        return ret;
 
out_dlclose:
        dlclose(so->handle);
out_free_so:
        free(so);
        goto out;
}
 
static struct fuse_module *fuse_find_module(const char *module)
{
        struct fuse_module *m;
        for (m = fuse_modules; m; m = m->next) {
                if (strcmp(module, m->name) == 0) {
                        m->ctr++;
                        break;
                }
        }
        return m;
}
 
static struct fuse_module *fuse_get_module(const char *module)
{
        struct fuse_module *m;
 
        pthread_mutex_lock(&fuse_context_lock);
        m = fuse_find_module(module);
        if (!m) {
                int err = fuse_load_so_module(module);
                if (!err)
                        m = fuse_find_module(module);
        }
        pthread_mutex_unlock(&fuse_context_lock);
        return m;
}
 
static void fuse_put_module(struct fuse_module *m)
{
        pthread_mutex_lock(&fuse_context_lock);
        if (m->so)
                assert(m->ctr > 0);
        /* Builtin modules may already have m->ctr == 0 */
        if (m->ctr > 0)
                m->ctr--;
        if (!m->ctr && m->so) {
                struct fusemod_so *so = m->so;
                assert(so->ctr > 0);
                so->ctr--;
                if (!so->ctr) {
                        struct fuse_module **mp;
                        for (mp = &fuse_modules; *mp;) {
                                if ((*mp)->so == so)
                                        fuse_unregister_module(*mp);
                                else
                                        mp = &(*mp)->next;
                        }
                        dlclose(so->handle);
                        free(so);
                }
        } else if (!m->ctr) {
                fuse_unregister_module(m);
        }
        pthread_mutex_unlock(&fuse_context_lock);
}
 
static void init_list_head(struct list_head *list)
{
        list->next = list;
        list->prev = list;
}
 
static int list_empty(const struct list_head *head)
{
        return head->next == head;
}
 
static void list_add(struct list_head *new, struct list_head *prev,
                     struct list_head *next)
{
        next->prev = new;
        new->next = next;
        new->prev = prev;
        prev->next = new;
}
 
static inline void list_add_head(struct list_head *new, struct list_head *head)
{
        list_add(new, head, head->next);
}
 
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
        list_add(new, head->prev, head);
}
 
static inline void list_del(struct list_head *entry)
{
        struct list_head *prev = entry->prev;
        struct list_head *next = entry->next;
 
        next->prev = prev;
        prev->next = next;
}
 
static inline int lru_enabled(struct fuse *f)
{
        return f->conf.remember > 0;
}
 
static struct node_lru *node_lru(struct node *node)
{
        return (struct node_lru *) node;
}
 
static size_t get_node_size(struct fuse *f)
{
        if (lru_enabled(f))
                return sizeof(struct node_lru);
        else
                return sizeof(struct node);
}
 
#ifdef FUSE_NODE_SLAB
static struct node_slab *list_to_slab(struct list_head *head)
{
        return (struct node_slab *) head;
}
 
static struct node_slab *node_to_slab(struct fuse *f, struct node *node)
{
        return (struct node_slab *) (((uintptr_t) node) & ~((uintptr_t) f->pagesize - 1));
}
 
static int alloc_slab(struct fuse *f)
{
        void *mem;
        struct node_slab *slab;
        char *start;
        size_t num;
        size_t i;
        size_t node_size = get_node_size(f);
 
        mem = mmap(NULL, f->pagesize, PROT_READ | PROT_WRITE,
                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
        if (mem == MAP_FAILED)
                return -1;
 
        slab = mem;
        init_list_head(&slab->freelist);
        slab->used = 0;
        num = (f->pagesize - sizeof(struct node_slab)) / node_size;
 
        start = (char *) mem + f->pagesize - num * node_size;
        for (i = 0; i < num; i++) {
                struct list_head *n;
 
                n = (struct list_head *) (start + i * node_size);
                list_add_tail(n, &slab->freelist);
        }
        list_add_tail(&slab->list, &f->partial_slabs);
 
        return 0;
}
 
static struct node *alloc_node(struct fuse *f)
{
        struct node_slab *slab;
        struct list_head *node;
 
        if (list_empty(&f->partial_slabs)) {
                int res = alloc_slab(f);
                if (res != 0)
                        return NULL;
        }
        slab = list_to_slab(f->partial_slabs.next);
        slab->used++;
        node = slab->freelist.next;
        list_del(node);
        if (list_empty(&slab->freelist)) {
                list_del(&slab->list);
                list_add_tail(&slab->list, &f->full_slabs);
        }
        memset(node, 0, sizeof(struct node));
 
        return (struct node *) node;
}
 
static void free_slab(struct fuse *f, struct node_slab *slab)
{
        int res;
 
        list_del(&slab->list);
        res = munmap(slab, f->pagesize);
        if (res == -1)
                fuse_log(FUSE_LOG_WARNING, "fuse warning: munmap(%p) failed\n",
                         slab);
}
 
static void free_node_mem(struct fuse *f, struct node *node)
{
        struct node_slab *slab = node_to_slab(f, node);
        struct list_head *n = (struct list_head *) node;
 
        slab->used--;
        if (slab->used) {
                if (list_empty(&slab->freelist)) {
                        list_del(&slab->list);
                        list_add_tail(&slab->list, &f->partial_slabs);
                }
                list_add_head(n, &slab->freelist);
        } else {
                free_slab(f, slab);
        }
}
#else
static struct node *alloc_node(struct fuse *f)
{
        return (struct node *) calloc(1, get_node_size(f));
}
 
static void free_node_mem(struct fuse *f, struct node *node)
{
        (void) f;
        free(node);
}
#endif
 
static size_t id_hash(struct fuse *f, fuse_ino_t ino)
{
        uint64_t hash = ((uint32_t) ino * 2654435761U) % f->id_table.size;
        uint64_t oldhash = hash % (f->id_table.size / 2);
 
        if (oldhash >= f->id_table.split)
                return oldhash;
        else
                return hash;
}
 
static struct node *get_node_nocheck(struct fuse *f, fuse_ino_t nodeid)
{
        size_t hash = id_hash(f, nodeid);
        struct node *node;
 
        for (node = f->id_table.array[hash]; node != NULL; node = node->id_next)
                if (node->nodeid == nodeid)
                        return node;
 
        return NULL;
}
 
static struct node *get_node(struct fuse *f, fuse_ino_t nodeid)
{
        struct node *node = get_node_nocheck(f, nodeid);
        if (!node) {
                fuse_log(FUSE_LOG_ERR, "fuse internal error: node %llu not found\n",
                        (unsigned long long) nodeid);
                abort();
        }
        return node;
}
 
static void curr_time(struct timespec *now);
static double diff_timespec(const struct timespec *t1,
                           const struct timespec *t2);
 
static void remove_node_lru(struct node *node)
{
        struct node_lru *lnode = node_lru(node);
        list_del(&lnode->lru);
        init_list_head(&lnode->lru);
}
 
static void set_forget_time(struct fuse *f, struct node *node)
{
        struct node_lru *lnode = node_lru(node);
 
        list_del(&lnode->lru);
        list_add_tail(&lnode->lru, &f->lru_table);
        curr_time(&lnode->forget_time);
}
 
static void free_node(struct fuse *f, struct node *node)
{
        if (node->name != node->inline_name)
                free(node->name);
        free_node_mem(f, node);
}
 
static void node_table_reduce(struct node_table *t)
{
        size_t newsize = t->size / 2;
        void *newarray;
 
        if (newsize < NODE_TABLE_MIN_SIZE)
                return;
 
        newarray = realloc(t->array, sizeof(struct node *) * newsize);
        if (newarray != NULL)
                t->array = newarray;
 
        t->size = newsize;
        t->split = t->size / 2;
}
 
static void remerge_id(struct fuse *f)
{
        struct node_table *t = &f->id_table;
        int iter;
 
        if (t->split == 0)
                node_table_reduce(t);
 
        for (iter = 8; t->split > 0 && iter; iter--) {
                struct node **upper;
 
                t->split--;
                upper = &t->array[t->split + t->size / 2];
                if (*upper) {
                        struct node **nodep;
 
                        for (nodep = &t->array[t->split]; *nodep;
                             nodep = &(*nodep)->id_next);
 
                        *nodep = *upper;
                        *upper = NULL;
                        break;
                }
        }
}
 
static void unhash_id(struct fuse *f, struct node *node)
{
        struct node **nodep = &f->id_table.array[id_hash(f, node->nodeid)];
 
        for (; *nodep != NULL; nodep = &(*nodep)->id_next)
                if (*nodep == node) {
                        *nodep = node->id_next;
                        f->id_table.use--;
 
                        if(f->id_table.use < f->id_table.size / 4)
                                remerge_id(f);
                        return;
                }
}
 
static int node_table_resize(struct node_table *t)
{
        size_t newsize = t->size * 2;
        void *newarray;
 
        newarray = realloc(t->array, sizeof(struct node *) * newsize);
        if (newarray == NULL)
                return -1;
 
        t->array = newarray;
        memset(t->array + t->size, 0, t->size * sizeof(struct node *));
        t->size = newsize;
        t->split = 0;
 
        return 0;
}
 
static void rehash_id(struct fuse *f)
{
        struct node_table *t = &f->id_table;
        struct node **nodep;
        struct node **next;
        size_t hash;
 
        if (t->split == t->size / 2)
                return;
 
        hash = t->split;
        t->split++;
        for (nodep = &t->array[hash]; *nodep != NULL; nodep = next) {
                struct node *node = *nodep;
                size_t newhash = id_hash(f, node->nodeid);
 
                if (newhash != hash) {
                        next = nodep;
                        *nodep = node->id_next;
                        node->id_next = t->array[newhash];
                        t->array[newhash] = node;
                } else {
                        next = &node->id_next;
                }
        }
        if (t->split == t->size / 2)
                node_table_resize(t);
}
 
static void hash_id(struct fuse *f, struct node *node)
{
        size_t hash = id_hash(f, node->nodeid);
        node->id_next = f->id_table.array[hash];
        f->id_table.array[hash] = node;
        f->id_table.use++;
 
        if (f->id_table.use >= f->id_table.size / 2)
                rehash_id(f);
}
 
static size_t name_hash(struct fuse *f, fuse_ino_t parent,
                        const char *name)
{
        uint64_t hash = parent;
        uint64_t oldhash;
 
        for (; *name; name++)
                hash = hash * 31 + (unsigned char) *name;
 
        hash %= f->name_table.size;
        oldhash = hash % (f->name_table.size / 2);
        if (oldhash >= f->name_table.split)
                return oldhash;
        else
                return hash;
}
 
static void unref_node(struct fuse *f, struct node *node);
 
static void remerge_name(struct fuse *f)
{
        struct node_table *t = &f->name_table;
        int iter;
 
        if (t->split == 0)
                node_table_reduce(t);
 
        for (iter = 8; t->split > 0 && iter; iter--) {
                struct node **upper;
 
                t->split--;
                upper = &t->array[t->split + t->size / 2];
                if (*upper) {
                        struct node **nodep;
 
                        for (nodep = &t->array[t->split]; *nodep;
                             nodep = &(*nodep)->name_next);
 
                        *nodep = *upper;
                        *upper = NULL;
                        break;
                }
        }
}
 
static void unhash_name(struct fuse *f, struct node *node)
{
        if (node->name) {
                size_t hash = name_hash(f, node->parent->nodeid, node->name);
                struct node **nodep = &f->name_table.array[hash];
 
                for (; *nodep != NULL; nodep = &(*nodep)->name_next)
                        if (*nodep == node) {
                                *nodep = node->name_next;
                                node->name_next = NULL;
                                unref_node(f, node->parent);
                                if (node->name != node->inline_name)
                                        free(node->name);
                                node->name = NULL;
                                node->parent = NULL;
                                f->name_table.use--;
 
                                if (f->name_table.use < f->name_table.size / 4)
                                        remerge_name(f);
                                return;
                        }
                fuse_log(FUSE_LOG_ERR,
                        "fuse internal error: unable to unhash node: %llu\n",
                        (unsigned long long) node->nodeid);
                abort();
        }
}
 
static void rehash_name(struct fuse *f)
{
        struct node_table *t = &f->name_table;
        struct node **nodep;
        struct node **next;
        size_t hash;
 
        if (t->split == t->size / 2)
                return;
 
        hash = t->split;
        t->split++;
        for (nodep = &t->array[hash]; *nodep != NULL; nodep = next) {
                struct node *node = *nodep;
                size_t newhash = name_hash(f, node->parent->nodeid, node->name);
 
                if (newhash != hash) {
                        next = nodep;
                        *nodep = node->name_next;
                        node->name_next = t->array[newhash];
                        t->array[newhash] = node;
                } else {
                        next = &node->name_next;
                }
        }
        if (t->split == t->size / 2)
                node_table_resize(t);
}
 
static int hash_name(struct fuse *f, struct node *node, fuse_ino_t parentid,
                     const char *name)
{
        size_t hash = name_hash(f, parentid, name);
        struct node *parent = get_node(f, parentid);
        if (strlen(name) < sizeof(node->inline_name)) {
                strcpy(node->inline_name, name);
                node->name = node->inline_name;
        } else {
                node->name = strdup(name);
                if (node->name == NULL)
                        return -1;
        }
 
        parent->refctr ++;
        node->parent = parent;
        node->name_next = f->name_table.array[hash];
        f->name_table.array[hash] = node;
        f->name_table.use++;
 
        if (f->name_table.use >= f->name_table.size / 2)
                rehash_name(f);
 
        return 0;
}
 
static void delete_node(struct fuse *f, struct node *node)
{
        if (f->conf.debug)
                fuse_log(FUSE_LOG_DEBUG, "DELETE: %llu\n",
                        (unsigned long long) node->nodeid);
 
        assert(node->treelock == 0);
        unhash_name(f, node);
        if (lru_enabled(f))
                remove_node_lru(node);
        unhash_id(f, node);
        free_node(f, node);
}
 
static void unref_node(struct fuse *f, struct node *node)
{
        assert(node->refctr > 0);
        node->refctr --;
        if (!node->refctr)
                delete_node(f, node);
}
 
static fuse_ino_t next_id(struct fuse *f)
{
        do {
                f->ctr = (f->ctr + 1) & 0xffffffff;
                if (!f->ctr)
                        f->generation ++;
        } while (f->ctr == 0 || f->ctr == FUSE_UNKNOWN_INO ||
                 get_node_nocheck(f, f->ctr) != NULL);
        return f->ctr;
}
 
static struct node *lookup_node(struct fuse *f, fuse_ino_t parent,
                                const char *name)
{
        size_t hash = name_hash(f, parent, name);
        struct node *node;
 
        for (node = f->name_table.array[hash]; node != NULL; node = node->name_next)
                if (node->parent->nodeid == parent &&
                    strcmp(node->name, name) == 0)
                        return node;
 
        return NULL;
}
 
static void inc_nlookup(struct node *node)
{
        if (!node->nlookup)
                node->refctr++;
        node->nlookup++;
}
 
static struct node *find_node(struct fuse *f, fuse_ino_t parent,
                              const char *name)
{
        struct node *node;
 
        pthread_mutex_lock(&f->lock);
        if (!name)
                node = get_node(f, parent);
        else
                node = lookup_node(f, parent, name);
        if (node == NULL) {
                node = alloc_node(f);
                if (node == NULL)
                        goto out_err;
 
                node->nodeid = next_id(f);
                node->generation = f->generation;
                if (f->conf.remember)
                        inc_nlookup(node);
 
                if (hash_name(f, node, parent, name) == -1) {
                        free_node(f, node);
                        node = NULL;
                        goto out_err;
                }
                hash_id(f, node);
                if (lru_enabled(f)) {
                        struct node_lru *lnode = node_lru(node);
                        init_list_head(&lnode->lru);
                }
        } else if (lru_enabled(f) && node->nlookup == 1) {
                remove_node_lru(node);
        }
        inc_nlookup(node);
out_err:
        pthread_mutex_unlock(&f->lock);
        return node;
}
 
static int lookup_path_in_cache(struct fuse *f,
                const char *path, fuse_ino_t *inop)
{
        char *tmp = strdup(path);
        if (!tmp)
                return -ENOMEM;
 
        pthread_mutex_lock(&f->lock);
        fuse_ino_t ino = FUSE_ROOT_ID;
 
        int err = 0;
        char *save_ptr;
        char *path_element = strtok_r(tmp, "/", &save_ptr);
        while (path_element != NULL) {
                struct node *node = lookup_node(f, ino, path_element);
                if (node == NULL) {
                        err = -ENOENT;
                        break;
                }
                ino = node->nodeid;
                path_element = strtok_r(NULL, "/", &save_ptr);
        }
        pthread_mutex_unlock(&f->lock);
        free(tmp);
 
        if (!err)
                *inop = ino;
        return err;
}
 
static char *add_name(char **buf, unsigned *bufsize, char *s, const char *name)
{
        size_t len = strlen(name);
 
        if (s - len <= *buf) {
                unsigned pathlen = *bufsize - (s - *buf);
                unsigned newbufsize = *bufsize;
                char *newbuf;
 
                while (newbufsize < pathlen + len + 1) {
                        if (newbufsize >= 0x80000000)
                                newbufsize = 0xffffffff;
                        else
                                newbufsize *= 2;
                }
 
                newbuf = realloc(*buf, newbufsize);
                if (newbuf == NULL)
                        return NULL;
 
                *buf = newbuf;
                s = newbuf + newbufsize - pathlen;
                memmove(s, newbuf + *bufsize - pathlen, pathlen);
                *bufsize = newbufsize;
        }
        s -= len;
        memcpy(s, name, len);
        s--;
        *s = '/';
 
        return s;
}
 
static void unlock_path(struct fuse *f, fuse_ino_t nodeid, struct node *wnode,
                        struct node *end)
{
        struct node *node;
 
        if (wnode) {
                assert(wnode->treelock == TREELOCK_WRITE);
                wnode->treelock = 0;
        }
 
        for (node = get_node(f, nodeid);
             node != end && node->nodeid != FUSE_ROOT_ID; node = node->parent) {
                assert(node->treelock != 0);
                assert(node->treelock != TREELOCK_WAIT_OFFSET);
                assert(node->treelock != TREELOCK_WRITE);
                node->treelock--;
                if (node->treelock == TREELOCK_WAIT_OFFSET)
                        node->treelock = 0;
        }
}
 
static int try_get_path(struct fuse *f, fuse_ino_t nodeid, const char *name,
                        char **path, struct node **wnodep, bool need_lock)
{
        unsigned bufsize = 256;
        char *buf;
        char *s;
        struct node *node;
        struct node *wnode = NULL;
        int err;
 
        *path = NULL;
 
        err = -ENOMEM;
        buf = malloc(bufsize);
        if (buf == NULL)
                goto out_err;
 
        s = buf + bufsize - 1;
        *s = '\0';
 
        if (name != NULL) {
                s = add_name(&buf, &bufsize, s, name);
                err = -ENOMEM;
                if (s == NULL)
                        goto out_free;
        }
 
        if (wnodep) {
                assert(need_lock);
                assert(name != NULL);
                wnode = lookup_node(f, nodeid, name);
                if (wnode) {
                        if (wnode->treelock != 0) {
                                if (wnode->treelock > 0)
                                        wnode->treelock += TREELOCK_WAIT_OFFSET;
                                err = -EAGAIN;
                                goto out_free;
                        }
                        wnode->treelock = TREELOCK_WRITE;
                }
        }
 
        for (node = get_node(f, nodeid); node->nodeid != FUSE_ROOT_ID;
             node = node->parent) {
                err = -ESTALE;
                if (node->name == NULL || node->parent == NULL)
                        goto out_unlock;
 
                err = -ENOMEM;
                s = add_name(&buf, &bufsize, s, node->name);
                if (s == NULL)
                        goto out_unlock;
 
                if (need_lock) {
                        err = -EAGAIN;
                        if (node->treelock < 0)
                                goto out_unlock;
 
                        node->treelock++;
                }
        }
 
        if (s[0])
                memmove(buf, s, bufsize - (s - buf));
        else
                strcpy(buf, "/");
 
        *path = buf;
        if (wnodep)
                *wnodep = wnode;
 
        return 0;
 
 out_unlock:
        if (need_lock)
                unlock_path(f, nodeid, wnode, node);
 out_free:
        free(buf);
 
 out_err:
        return err;
}
 
static int try_get_path2(struct fuse *f, fuse_ino_t nodeid1, const char *name1,
                         fuse_ino_t nodeid2, const char *name2,
                         char **path1, char **path2,
                         struct node **wnode1, struct node **wnode2)
{
        int err;
 
        /* FIXME: locking two paths needs deadlock checking */
        err = try_get_path(f, nodeid1, name1, path1, wnode1, true);
        if (!err) {
                err = try_get_path(f, nodeid2, name2, path2, wnode2, true);
                if (err) {
                        struct node *wn1 = wnode1 ? *wnode1 : NULL;
 
                        unlock_path(f, nodeid1, wn1, NULL);
                        free(*path1);
                }
        }
        return err;
}
 
static void queue_element_wakeup(struct fuse *f, struct lock_queue_element *qe)
{
        int err;
 
        if (!qe->path1) {
                /* Just waiting for it to be unlocked */
                if (get_node(f, qe->nodeid1)->treelock == 0)
                        pthread_cond_signal(&qe->cond);
 
                return;
        }
 
        if (qe->done)
                return;  // Don't try to double-lock the element
 
        if (!qe->path2) {
                err = try_get_path(f, qe->nodeid1, qe->name1, qe->path1,
                                   qe->wnode1, true);
        } else {
                err = try_get_path2(f, qe->nodeid1, qe->name1, qe->nodeid2,
                                    qe->name2, qe->path1, qe->path2, qe->wnode1,
                                    qe->wnode2);
        }
 
        if (err == -EAGAIN)
                return;  /* keep trying */
 
        qe->err = err;
        qe->done = true;
        pthread_cond_signal(&qe->cond);
}
 
static void wake_up_queued(struct fuse *f)
{
        struct lock_queue_element *qe;
 
        for (qe = f->lockq; qe != NULL; qe = qe->next)
                queue_element_wakeup(f, qe);
}
 
static void debug_path(struct fuse *f, const char *msg, fuse_ino_t nodeid,
                       const char *name, bool wr)
{
        if (f->conf.debug) {
                struct node *wnode = NULL;
 
                if (wr)
                        wnode = lookup_node(f, nodeid, name);
 
                if (wnode) {
                        fuse_log(FUSE_LOG_DEBUG, "%s %llu (w)\n",
                                msg, (unsigned long long) wnode->nodeid);
                } else {
                        fuse_log(FUSE_LOG_DEBUG, "%s %llu\n",
                                msg, (unsigned long long) nodeid);
                }
        }
}
 
static void queue_path(struct fuse *f, struct lock_queue_element *qe)
{
        struct lock_queue_element **qp;
 
        qe->done = false;
        pthread_cond_init(&qe->cond, NULL);
        qe->next = NULL;
        for (qp = &f->lockq; *qp != NULL; qp = &(*qp)->next);
        *qp = qe;
}
 
static void dequeue_path(struct fuse *f, struct lock_queue_element *qe)
{
        struct lock_queue_element **qp;
 
        pthread_cond_destroy(&qe->cond);
        for (qp = &f->lockq; *qp != qe; qp = &(*qp)->next);
        *qp = qe->next;
}
 
static int wait_path(struct fuse *f, struct lock_queue_element *qe)
{
        queue_path(f, qe);
 
        do {
                pthread_cond_wait(&qe->cond, &f->lock);
        } while (!qe->done);
 
        dequeue_path(f, qe);
 
        return qe->err;
}
 
static int get_path_common(struct fuse *f, fuse_ino_t nodeid, const char *name,
                           char **path, struct node **wnode)
{
        int err;
 
        pthread_mutex_lock(&f->lock);
        err = try_get_path(f, nodeid, name, path, wnode, true);
        if (err == -EAGAIN) {
                struct lock_queue_element qe = {
                        .nodeid1 = nodeid,
                        .name1 = name,
                        .path1 = path,
                        .wnode1 = wnode,
                };
                debug_path(f, "QUEUE PATH", nodeid, name, !!wnode);
                err = wait_path(f, &qe);
                debug_path(f, "DEQUEUE PATH", nodeid, name, !!wnode);
        }
        pthread_mutex_unlock(&f->lock);
 
        return err;
}
 
static int get_path(struct fuse *f, fuse_ino_t nodeid, char **path)
{
        return get_path_common(f, nodeid, NULL, path, NULL);
}
 
static int get_path_nullok(struct fuse *f, fuse_ino_t nodeid, char **path)
{
        int err = 0;
 
        if (f->conf.nullpath_ok) {
                *path = NULL;
        } else {
                err = get_path_common(f, nodeid, NULL, path, NULL);
                if (err == -ESTALE)
                        err = 0;
        }
 
        return err;
}
 
static int get_path_name(struct fuse *f, fuse_ino_t nodeid, const char *name,
                         char **path)
{
        return get_path_common(f, nodeid, name, path, NULL);
}
 
static int get_path_wrlock(struct fuse *f, fuse_ino_t nodeid, const char *name,
                           char **path, struct node **wnode)
{
        return get_path_common(f, nodeid, name, path, wnode);
}
 
#if defined(__FreeBSD__)
#define CHECK_DIR_LOOP
#endif
 
#if defined(CHECK_DIR_LOOP)
static int check_dir_loop(struct fuse *f,
                          fuse_ino_t nodeid1, const char *name1,
                          fuse_ino_t nodeid2, const char *name2)
{
        struct node *node, *node1, *node2;
        fuse_ino_t id1, id2;
 
        node1 = lookup_node(f, nodeid1, name1);
        id1 = node1 ? node1->nodeid : nodeid1;
 
        node2 = lookup_node(f, nodeid2, name2);
        id2 = node2 ? node2->nodeid : nodeid2;
 
        for (node = get_node(f, id2); node->nodeid != FUSE_ROOT_ID;
             node = node->parent) {
                if (node->name == NULL || node->parent == NULL)
                        break;
 
                if (node->nodeid != id2 && node->nodeid == id1)
                        return -EINVAL;
        }
 
        if (node2)
        {
                for (node = get_node(f, id1); node->nodeid != FUSE_ROOT_ID;
                     node = node->parent) {
                        if (node->name == NULL || node->parent == NULL)
                                break;
 
                        if (node->nodeid != id1 && node->nodeid == id2)
                                return -ENOTEMPTY;
                }
        }
 
        return 0;
}
#endif
 
static int get_path2(struct fuse *f, fuse_ino_t nodeid1, const char *name1,
                     fuse_ino_t nodeid2, const char *name2,
                     char **path1, char **path2,
                     struct node **wnode1, struct node **wnode2)
{
        int err;
 
        pthread_mutex_lock(&f->lock);
 
#if defined(CHECK_DIR_LOOP)
        if (name1)
        {
                // called during rename; perform dir loop check
                err = check_dir_loop(f, nodeid1, name1, nodeid2, name2);
                if (err)
                        goto out_unlock;
        }
#endif
 
        err = try_get_path2(f, nodeid1, name1, nodeid2, name2,
                            path1, path2, wnode1, wnode2);
        if (err == -EAGAIN) {
                struct lock_queue_element qe = {
                        .nodeid1 = nodeid1,
                        .name1 = name1,
                        .path1 = path1,
                        .wnode1 = wnode1,
                        .nodeid2 = nodeid2,
                        .name2 = name2,
                        .path2 = path2,
                        .wnode2 = wnode2,
                };
 
                debug_path(f, "QUEUE PATH1", nodeid1, name1, !!wnode1);
                debug_path(f, "      PATH2", nodeid2, name2, !!wnode2);
                err = wait_path(f, &qe);
                debug_path(f, "DEQUEUE PATH1", nodeid1, name1, !!wnode1);
                debug_path(f, "        PATH2", nodeid2, name2, !!wnode2);
        }
 
#if defined(CHECK_DIR_LOOP)
out_unlock:
#endif
        pthread_mutex_unlock(&f->lock);
 
        return err;
}
 
static void free_path_wrlock(struct fuse *f, fuse_ino_t nodeid,
                             struct node *wnode, char *path)
{
        pthread_mutex_lock(&f->lock);
        unlock_path(f, nodeid, wnode, NULL);
        if (f->lockq)
                wake_up_queued(f);
        pthread_mutex_unlock(&f->lock);
        free(path);
}
 
static void free_path(struct fuse *f, fuse_ino_t nodeid, char *path)
{
        if (path)
                free_path_wrlock(f, nodeid, NULL, path);
}
 
static void free_path2(struct fuse *f, fuse_ino_t nodeid1, fuse_ino_t nodeid2,
                       struct node *wnode1, struct node *wnode2,
                       char *path1, char *path2)
{
        pthread_mutex_lock(&f->lock);
        unlock_path(f, nodeid1, wnode1, NULL);
        unlock_path(f, nodeid2, wnode2, NULL);
        wake_up_queued(f);
        pthread_mutex_unlock(&f->lock);
        free(path1);
        free(path2);
}
 
static void forget_node(struct fuse *f, fuse_ino_t nodeid, uint64_t nlookup)
{
        struct node *node;
        if (nodeid == FUSE_ROOT_ID)
                return;
        pthread_mutex_lock(&f->lock);
        node = get_node(f, nodeid);
 
        /*
         * Node may still be locked due to interrupt idiocy in open,
         * create and opendir
         */
        while (node->nlookup == nlookup && node->treelock) {
                struct lock_queue_element qe = {
                        .nodeid1 = nodeid,
                };
 
                debug_path(f, "QUEUE PATH (forget)", nodeid, NULL, false);
                queue_path(f, &qe);
 
                do {
                        pthread_cond_wait(&qe.cond, &f->lock);
                } while (node->nlookup == nlookup && node->treelock);
 
                dequeue_path(f, &qe);
                debug_path(f, "DEQUEUE_PATH (forget)", nodeid, NULL, false);
        }
 
        assert(node->nlookup >= nlookup);
        node->nlookup -= nlookup;
        if (!node->nlookup) {
                unref_node(f, node);
        } else if (lru_enabled(f) && node->nlookup == 1) {
                set_forget_time(f, node);
        }
        pthread_mutex_unlock(&f->lock);
}
 
static void unlink_node(struct fuse *f, struct node *node)
{
        if (f->conf.remember) {
                assert(node->nlookup > 1);
                node->nlookup--;
        }
        unhash_name(f, node);
}
 
static void remove_node(struct fuse *f, fuse_ino_t dir, const char *name)
{
        struct node *node;
 
        pthread_mutex_lock(&f->lock);
        node = lookup_node(f, dir, name);
        if (node != NULL)
                unlink_node(f, node);
        pthread_mutex_unlock(&f->lock);
}
 
static int rename_node(struct fuse *f, fuse_ino_t olddir, const char *oldname,
                       fuse_ino_t newdir, const char *newname, int hide)
{
        struct node *node;
        struct node *newnode;
        int err = 0;
 
        pthread_mutex_lock(&f->lock);
        node  = lookup_node(f, olddir, oldname);
        newnode  = lookup_node(f, newdir, newname);
        if (node == NULL)
                goto out;
 
        if (newnode != NULL) {
                if (hide) {
                        fuse_log(FUSE_LOG_ERR, "fuse: hidden file got created during hiding\n");
                        err = -EBUSY;
                        goto out;
                }
                unlink_node(f, newnode);
        }
 
        unhash_name(f, node);
        if (hash_name(f, node, newdir, newname) == -1) {
                err = -ENOMEM;
                goto out;
        }
 
        if (hide)
                node->is_hidden = 1;
 
out:
        pthread_mutex_unlock(&f->lock);
        return err;
}
 
static int exchange_node(struct fuse *f, fuse_ino_t olddir, const char *oldname,
                         fuse_ino_t newdir, const char *newname)
{
        struct node *oldnode;
        struct node *newnode;
        int err;
 
        pthread_mutex_lock(&f->lock);
        oldnode  = lookup_node(f, olddir, oldname);
        newnode  = lookup_node(f, newdir, newname);
 
        if (oldnode)
                unhash_name(f, oldnode);
        if (newnode)
                unhash_name(f, newnode);
 
        err = -ENOMEM;
        if (oldnode) {
                if (hash_name(f, oldnode, newdir, newname) == -1)
                        goto out;
        }
        if (newnode) {
                if (hash_name(f, newnode, olddir, oldname) == -1)
                        goto out;
        }
        err = 0;
out:
        pthread_mutex_unlock(&f->lock);
        return err;
}
 
static void set_stat(struct fuse *f, fuse_ino_t nodeid, struct stat *stbuf)
{
        if (!f->conf.use_ino)
                stbuf->st_ino = nodeid;
        if (f->conf.set_mode) {
                if (f->conf.dmask && S_ISDIR(stbuf->st_mode))
                        stbuf->st_mode = (stbuf->st_mode & S_IFMT) |
                                         (0777 & ~f->conf.dmask);
                else if (f->conf.fmask)
                        stbuf->st_mode = (stbuf->st_mode & S_IFMT) |
                                         (0777 & ~f->conf.fmask);
                else
                        stbuf->st_mode = (stbuf->st_mode & S_IFMT) |
                                         (0777 & ~f->conf.umask);
        }
        if (f->conf.set_uid)
                stbuf->st_uid = f->conf.uid;
        if (f->conf.set_gid)
                stbuf->st_gid = f->conf.gid;
}
 
#ifdef HAVE_STATX
static void set_statx(struct fuse *f, fuse_ino_t nodeid, struct statx *stxbuf)
{
        if (!f->conf.use_ino)
                stxbuf->stx_ino = nodeid;
        if (f->conf.set_mode) {
                if (f->conf.dmask && S_ISDIR(stxbuf->stx_mode))
                        stxbuf->stx_mode = (stxbuf->stx_mode & S_IFMT) |
                                         (0777 & ~f->conf.dmask);
                else if (f->conf.fmask)
                        stxbuf->stx_mode = (stxbuf->stx_mode & S_IFMT) |
                                         (0777 & ~f->conf.fmask);
                else
                        stxbuf->stx_mode = (stxbuf->stx_mode & S_IFMT) |
                                         (0777 & ~f->conf.umask);
        }
        if (f->conf.set_uid)
                stxbuf->stx_uid = f->conf.uid;
        if (f->conf.set_gid)
                stxbuf->stx_gid = f->conf.gid;
}
#endif
 
static struct fuse *req_fuse(fuse_req_t req)
{
        return (struct fuse *) fuse_req_userdata(req);
}
 
static void fuse_intr_sighandler(int sig)
{
        (void) sig;
        /* Nothing to do */
}
 
struct fuse_intr_data {
        pthread_t id;
        pthread_cond_t cond;
        int finished;
};
 
static void fuse_interrupt(fuse_req_t req, void *d_)
{
        struct fuse_intr_data *d = d_;
        struct fuse *f = req_fuse(req);
 
        if (d->id == pthread_self())
                return;
 
        pthread_mutex_lock(&f->lock);
        while (!d->finished) {
                struct timeval now;
                struct timespec timeout;
 
                pthread_kill(d->id, f->conf.intr_signal);
                gettimeofday(&now, NULL);
                timeout.tv_sec = now.tv_sec + 1;
                timeout.tv_nsec = now.tv_usec * 1000;
                pthread_cond_timedwait(&d->cond, &f->lock, &timeout);
        }
        pthread_mutex_unlock(&f->lock);
}
 
static void fuse_do_finish_interrupt(struct fuse *f, fuse_req_t req,
                                     struct fuse_intr_data *d)
{
        pthread_mutex_lock(&f->lock);
        d->finished = 1;
        pthread_cond_broadcast(&d->cond);
        pthread_mutex_unlock(&f->lock);
        fuse_req_interrupt_func(req, NULL, NULL);
        pthread_cond_destroy(&d->cond);
}
 
static void fuse_do_prepare_interrupt(fuse_req_t req, struct fuse_intr_data *d)
{
        d->id = pthread_self();
        pthread_cond_init(&d->cond, NULL);
        d->finished = 0;
        fuse_req_interrupt_func(req, fuse_interrupt, d);
}
 
static inline void fuse_finish_interrupt(struct fuse *f, fuse_req_t req,
                                         struct fuse_intr_data *d)
{
        if (f->conf.intr)
                fuse_do_finish_interrupt(f, req, d);
}
 
static inline void fuse_prepare_interrupt(struct fuse *f, fuse_req_t req,
                                          struct fuse_intr_data *d)
{
        if (f->conf.intr)
                fuse_do_prepare_interrupt(req, d);
}
 
static const char* file_info_string(struct fuse_file_info *fi,
                              char* buf, size_t len)
{
        if(fi == NULL)
                return "NULL";
        snprintf(buf, len, "%llu", (unsigned long long) fi->fh);
        return buf;
}
 
int fuse_fs_getattr(struct fuse_fs *fs, const char *path, struct stat *buf,
                    struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.getattr)
                return -ENOSYS;
 
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "getattr[%s] %s\n",
                        file_info_string(fi, buf, sizeof(buf)),
                        path);
        }
        return fs->op.getattr(path, buf, fi);
}
 
int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
                   const char *newpath, unsigned int flags)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.rename)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "rename %s %s 0x%x\n", oldpath, newpath,
                        flags);
 
        return fs->op.rename(oldpath, newpath, flags);
}
 
int fuse_fs_unlink(struct fuse_fs *fs, const char *path)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.unlink)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "unlink %s\n", path);
 
        return fs->op.unlink(path);
}
 
int fuse_fs_rmdir(struct fuse_fs *fs, const char *path)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.rmdir)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "rmdir %s\n", path);
 
        return fs->op.rmdir(path);
}
 
int fuse_fs_symlink(struct fuse_fs *fs, const char *linkname, const char *path)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.symlink)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "symlink %s %s\n", linkname, path);
 
        return fs->op.symlink(linkname, path);
}
 
int fuse_fs_link(struct fuse_fs *fs, const char *oldpath, const char *newpath)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.link)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "link %s %s\n", oldpath, newpath);
 
        return fs->op.link(oldpath, newpath);
}
 
int fuse_fs_release(struct fuse_fs *fs,  const char *path,
                    struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.release)
                return 0;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "release%s[%llu] flags: 0x%x\n",
                        fi->flush ? "+flush" : "",
                        (unsigned long long) fi->fh, fi->flags);
 
        return fs->op.release(path, fi);
}
 
int fuse_fs_opendir(struct fuse_fs *fs, const char *path,
                    struct fuse_file_info *fi)
{
        int err;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.opendir)
                return 0;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "opendir flags: 0x%x %s\n", fi->flags,
                        path);
 
        err = fs->op.opendir(path, fi);
 
        if (fs->debug && !err)
                fuse_log(FUSE_LOG_DEBUG, "   opendir[%llu] flags: 0x%x %s\n",
                        (unsigned long long) fi->fh, fi->flags, path);
 
        return err;
}
 
int fuse_fs_open(struct fuse_fs *fs, const char *path,
                 struct fuse_file_info *fi)
{
        int err;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.open)
                return 0;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "open flags: 0x%x %s\n", fi->flags,
                        path);
 
        err = fs->op.open(path, fi);
 
        if (fs->debug && !err)
                fuse_log(FUSE_LOG_DEBUG, "   open[%llu] flags: 0x%x %s\n",
                        (unsigned long long) fi->fh, fi->flags, path);
 
        return err;
}
 
static void fuse_free_buf(struct fuse_bufvec *buf)
{
        if (buf != NULL) {
                size_t i;
 
                for (i = 0; i < buf->count; i++)
                        if (!(buf->buf[i].flags & FUSE_BUF_IS_FD))
                                free(buf->buf[i].mem);
                free(buf);
        }
}
 
int fuse_fs_read_buf(struct fuse_fs *fs, const char *path,
                     struct fuse_bufvec **bufp, size_t size, off_t off,
                     struct fuse_file_info *fi)
{
        int res;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.read && !fs->op.read_buf)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG,
                        "read[%llu] %zu bytes from %llu flags: 0x%x\n",
                        (unsigned long long) fi->fh,
                        size, (unsigned long long) off, fi->flags);
 
        if (fs->op.read_buf) {
                res = fs->op.read_buf(path, bufp, size, off, fi);
        } else {
                struct fuse_bufvec *buf;
                void *mem;
 
                buf = malloc(sizeof(struct fuse_bufvec));
                if (buf == NULL)
                        return -ENOMEM;
 
                mem = malloc(size);
                if (mem == NULL) {
                        free(buf);
                        return -ENOMEM;
                }
                *buf = FUSE_BUFVEC_INIT(size);
                buf->buf[0].mem = mem;
                *bufp = buf;
 
                res = fs->op.read(path, mem, size, off, fi);
                if (res >= 0)
                        buf->buf[0].size = res;
        }
 
        if (fs->debug && res >= 0)
                fuse_log(FUSE_LOG_DEBUG, "   read[%llu] %zu bytes from %llu\n",
                        (unsigned long long) fi->fh,
                        fuse_buf_size(*bufp),
                        (unsigned long long) off);
        if (res >= 0 && fuse_buf_size(*bufp) > size)
                fuse_log(FUSE_LOG_ERR, "fuse: read too many bytes\n");
 
        if (res < 0)
                return res;
 
        return 0;
}
 
int fuse_fs_read(struct fuse_fs *fs, const char *path, char *mem, size_t size,
                 off_t off, struct fuse_file_info *fi)
{
        int res;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.read && !fs->op.read_buf)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG,
                        "read[%llu] %zu bytes from %llu flags: 0x%x\n",
                        (unsigned long long) fi->fh,
                        size, (unsigned long long) off, fi->flags);
 
        if (fs->op.read_buf) {
                struct fuse_bufvec *buf = NULL;
 
                res = fs->op.read_buf(path, &buf, size, off, fi);
                if (res == 0) {
                        struct fuse_bufvec dst = FUSE_BUFVEC_INIT(size);
 
                        dst.buf[0].mem = mem;
                        res = fuse_buf_copy(&dst, buf, 0);
                }
                fuse_free_buf(buf);
        } else {
                res = fs->op.read(path, mem, size, off, fi);
        }
 
        if (fs->debug && res >= 0)
                fuse_log(FUSE_LOG_DEBUG, "   read[%llu] %u bytes from %llu\n",
                        (unsigned long long) fi->fh,
                        res,
                        (unsigned long long) off);
        if (res >= 0 && res > (int) size)
                fuse_log(FUSE_LOG_ERR, "fuse: read too many bytes\n");
 
        return res;
}
 
int fuse_fs_write_buf(struct fuse_fs *fs, const char *path,
                      struct fuse_bufvec *buf, off_t off,
                      struct fuse_file_info *fi)
{
        int res;
        size_t size;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.write_buf && !fs->op.write)
                return -ENOSYS;
 
        size = fuse_buf_size(buf);
        assert(buf->idx == 0 && buf->off == 0);
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG,
                        "write%s[%llu] %zu bytes to %llu flags: 0x%x\n",
                        fi->writepage ? "page" : "",
                        (unsigned long long) fi->fh,
                        size,
                        (unsigned long long) off,
                        fi->flags);
 
        if (fs->op.write_buf) {
                res = fs->op.write_buf(path, buf, off, fi);
        } else {
                void *mem = NULL;
                struct fuse_buf *flatbuf;
                struct fuse_bufvec tmp = FUSE_BUFVEC_INIT(size);
 
                if (buf->count == 1 &&
                    !(buf->buf[0].flags & FUSE_BUF_IS_FD)) {
                        flatbuf = &buf->buf[0];
                } else {
                        res = -ENOMEM;
                        mem = malloc(size);
                        if (mem == NULL)
                                goto out;
 
                        tmp.buf[0].mem = mem;
                        res = fuse_buf_copy(&tmp, buf, 0);
                        if (res <= 0)
                                goto out_free;
 
                        tmp.buf[0].size = res;
                        flatbuf = &tmp.buf[0];
                }
 
                res = fs->op.write(path, flatbuf->mem, flatbuf->size,
                                   off, fi);
out_free:
                free(mem);
        }
out:
        if (fs->debug && res >= 0)
                fuse_log(FUSE_LOG_DEBUG, "   write%s[%llu] %u bytes to %llu\n",
                        fi->writepage ? "page" : "",
                        (unsigned long long) fi->fh, res,
                        (unsigned long long) off);
        if (res > (int) size)
                fuse_log(FUSE_LOG_ERR, "fuse: wrote too many bytes\n");
 
        return res;
}
 
int fuse_fs_write(struct fuse_fs *fs, const char *path, const char *mem,
                  size_t size, off_t off, struct fuse_file_info *fi)
{
        struct fuse_bufvec bufv = FUSE_BUFVEC_INIT(size);
 
        bufv.buf[0].mem = (void *) mem;
 
        return fuse_fs_write_buf(fs, path, &bufv, off, fi);
}
 
int fuse_fs_fsync(struct fuse_fs *fs, const char *path, int datasync,
                  struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.fsync)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "fsync[%llu] datasync: %i\n",
                        (unsigned long long) fi->fh, datasync);
 
        return fs->op.fsync(path, datasync, fi);
}
 
int fuse_fs_fsyncdir(struct fuse_fs *fs, const char *path, int datasync,
                     struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.fsyncdir)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "fsyncdir[%llu] datasync: %i\n",
                        (unsigned long long) fi->fh, datasync);
 
        return fs->op.fsyncdir(path, datasync, fi);
}
 
int fuse_fs_flush(struct fuse_fs *fs, const char *path,
                  struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.flush)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "flush[%llu]\n",
                        (unsigned long long) fi->fh);
 
        return fs->op.flush(path, fi);
}
 
int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf)
{
        fuse_get_context()->private_data = fs->user_data;
        if (fs->op.statfs) {
                if (fs->debug)
                        fuse_log(FUSE_LOG_DEBUG, "statfs %s\n", path);
 
                return fs->op.statfs(path, buf);
        } else {
                buf->f_namemax = 255;
                buf->f_bsize = 512;
                return 0;
        }
}
 
int fuse_fs_releasedir(struct fuse_fs *fs, const char *path,
                       struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.releasedir)
                return  0;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "releasedir[%llu] flags: 0x%x\n",
                        (unsigned long long) fi->fh, fi->flags);
 
        return fs->op.releasedir(path, fi);
}
 
int fuse_fs_readdir(struct fuse_fs *fs, const char *path, void *buf,
                    fuse_fill_dir_t filler, off_t off,
                    struct fuse_file_info *fi,
                    enum fuse_readdir_flags flags)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.readdir)
                return -ENOSYS;
        if (fs->debug) {
                fuse_log(FUSE_LOG_DEBUG, "readdir%s[%llu] from %llu\n",
                        (flags & FUSE_READDIR_PLUS) ? "plus" : "",
                        (unsigned long long) fi->fh,
                        (unsigned long long) off);
        }
 
        return fs->op.readdir(path, buf, filler, off, fi, flags);
}
 
int fuse_fs_create(struct fuse_fs *fs, const char *path, mode_t mode,
                   struct fuse_file_info *fi)
{
        int err;
 
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.create)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG,
                        "create flags: 0x%x %s 0%o umask=0%03o\n",
                        fi->flags, path, mode,
                        fuse_get_context()->umask);
 
        err = fs->op.create(path, mode, fi);
 
        if (fs->debug && !err)
                fuse_log(FUSE_LOG_DEBUG, "   create[%llu] flags: 0x%x %s\n",
                        (unsigned long long) fi->fh, fi->flags, path);
 
        return err;
}
 
int fuse_fs_lock(struct fuse_fs *fs, const char *path,
                 struct fuse_file_info *fi, int cmd, struct flock *lock)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.lock)
                return -ENOSYS;
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "lock[%llu] %s %s start: %llu len: %llu pid: %llu\n",
                        (unsigned long long) fi->fh,
                        (cmd == F_GETLK ? "F_GETLK" :
                         (cmd == F_SETLK ? "F_SETLK" :
                          (cmd == F_SETLKW ? "F_SETLKW" : "???"))),
                        (lock->l_type == F_RDLCK ? "F_RDLCK" :
                         (lock->l_type == F_WRLCK ? "F_WRLCK" :
                          (lock->l_type == F_UNLCK ? "F_UNLCK" :
                           "???"))),
                        (unsigned long long) lock->l_start,
                        (unsigned long long) lock->l_len,
                        (unsigned long long) lock->l_pid);
 
        return fs->op.lock(path, fi, cmd, lock);
}
 
int fuse_fs_flock(struct fuse_fs *fs, const char *path,
                  struct fuse_file_info *fi, int op)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.flock)
                return -ENOSYS;
 
        if (fs->debug) {
                int xop = op & ~LOCK_NB;
 
                fuse_log(FUSE_LOG_DEBUG, "lock[%llu] %s%s\n",
                        (unsigned long long) fi->fh,
                        xop == LOCK_SH ? "LOCK_SH" :
                        (xop == LOCK_EX ? "LOCK_EX" :
                         (xop == LOCK_UN ? "LOCK_UN" : "???")),
                        (op & LOCK_NB) ? "|LOCK_NB" : "");
        }
        return fs->op.flock(path, fi, op);
}
 
int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid,
                  gid_t gid, struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.chown)
                return -ENOSYS;
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "chown[%s] %s %lu %lu\n",
                        file_info_string(fi, buf, sizeof(buf)),
                        path, (unsigned long) uid, (unsigned long) gid);
        }
        return fs->op.chown(path, uid, gid, fi);
}
 
int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size,
                      struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.truncate)
                return -ENOSYS;
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "truncate[%s] %llu\n",
                        file_info_string(fi, buf, sizeof(buf)),
                        (unsigned long long) size);
        }
        return fs->op.truncate(path, size, fi);
}
 
int fuse_fs_utimens(struct fuse_fs *fs, const char *path,
                    const struct timespec tv[2], struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.utimens)
                return -ENOSYS;
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "utimens[%s] %s %jd.%09ld %jd.%09ld\n",
                         file_info_string(fi, buf, sizeof(buf)),
                         path, (intmax_t)tv[0].tv_sec, tv[0].tv_nsec,
                         (intmax_t)tv[1].tv_sec, tv[1].tv_nsec);
        }
        return fs->op.utimens(path, tv, fi);
}
 
int fuse_fs_access(struct fuse_fs *fs, const char *path, int mask)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.access)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "access %s 0%o\n", path, mask);
 
        return fs->op.access(path, mask);
}
 
int fuse_fs_readlink(struct fuse_fs *fs, const char *path, char *buf,
                     size_t len)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.readlink)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "readlink %s %lu\n", path,
                        (unsigned long) len);
 
        return fs->op.readlink(path, buf, len);
}
 
int fuse_fs_mknod(struct fuse_fs *fs, const char *path, mode_t mode,
                  dev_t rdev)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.mknod)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "mknod %s 0%o 0x%llx umask=0%03o\n",
                        path, mode, (unsigned long long) rdev,
                        fuse_get_context()->umask);
 
        return fs->op.mknod(path, mode, rdev);
}
 
int fuse_fs_mkdir(struct fuse_fs *fs, const char *path, mode_t mode)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.mkdir)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "mkdir %s 0%o umask=0%03o\n",
                        path, mode, fuse_get_context()->umask);
 
        return fs->op.mkdir(path, mode);
}
 
int fuse_fs_setxattr(struct fuse_fs *fs, const char *path, const char *name,
                     const char *value, size_t size, int flags)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.setxattr)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "setxattr %s %s %lu 0x%x\n",
                        path, name, (unsigned long) size, flags);
 
        return fs->op.setxattr(path, name, value, size, flags);
}
 
int fuse_fs_getxattr(struct fuse_fs *fs, const char *path, const char *name,
                     char *value, size_t size)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.getxattr)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "getxattr %s %s %lu\n",
                        path, name, (unsigned long) size);
 
        return fs->op.getxattr(path, name, value, size);
}
 
int fuse_fs_listxattr(struct fuse_fs *fs, const char *path, char *list,
                      size_t size)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.listxattr)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "listxattr %s %lu\n",
                        path, (unsigned long) size);
 
        return fs->op.listxattr(path, list, size);
}
 
int fuse_fs_bmap(struct fuse_fs *fs, const char *path, size_t blocksize,
                 uint64_t *idx)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.bmap)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "bmap %s blocksize: %lu index: %llu\n",
                        path, (unsigned long) blocksize,
                        (unsigned long long) *idx);
 
        return fs->op.bmap(path, blocksize, idx);
}
 
int fuse_fs_removexattr(struct fuse_fs *fs, const char *path, const char *name)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.removexattr)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "removexattr %s %s\n", path, name);
 
        return fs->op.removexattr(path, name);
}
 
int fuse_fs_ioctl(struct fuse_fs *fs, const char *path, unsigned int cmd,
                  void *arg, struct fuse_file_info *fi, unsigned int flags,
                  void *data)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.ioctl)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "ioctl[%llu] 0x%x flags: 0x%x\n",
                        (unsigned long long) fi->fh, cmd, flags);
 
        return fs->op.ioctl(path, cmd, arg, fi, flags, data);
}
 
int fuse_fs_poll(struct fuse_fs *fs, const char *path,
                 struct fuse_file_info *fi, struct fuse_pollhandle *ph,
                 unsigned *reventsp)
{
        int res;
 
        fuse_get_context()->private_data = fs->user_data;
 
        if (!fs->op.poll) {
                fuse_pollhandle_destroy(ph);
                return -ENOSYS;
        }
 
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "poll[%llu] ph: %p, events 0x%x\n",
                        (unsigned long long) fi->fh, ph,
                        fi->poll_events);
 
        res = fs->op.poll(path, fi, ph, reventsp);
 
        if (fs->debug && !res)
                fuse_log(FUSE_LOG_DEBUG, "   poll[%llu] revents: 0x%x\n",
                        (unsigned long long) fi->fh, *reventsp);
 
        return res;
}
 
int fuse_fs_fallocate(struct fuse_fs *fs, const char *path, int mode,
                off_t offset, off_t length, struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.fallocate)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "fallocate %s mode %x, offset: %llu, length: %llu\n",
                        path,
                        mode,
                        (unsigned long long) offset,
                        (unsigned long long) length);
 
        return fs->op.fallocate(path, mode, offset, length, fi);
}
 
ssize_t fuse_fs_copy_file_range(struct fuse_fs *fs, const char *path_in,
                                struct fuse_file_info *fi_in, off_t off_in,
                                const char *path_out,
                                struct fuse_file_info *fi_out, off_t off_out,
                                size_t len, int flags)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.copy_file_range)
                return -ENOSYS;
        if (fs->debug)
                fuse_log(FUSE_LOG_DEBUG, "copy_file_range from %s:%llu to "
                                "%s:%llu, length: %llu\n",
                        path_in,
                        (unsigned long long) off_in,
                        path_out,
                        (unsigned long long) off_out,
                        (unsigned long long) len);
 
        return fs->op.copy_file_range(path_in, fi_in, off_in, path_out,
                                      fi_out, off_out, len, flags);
}
 
off_t fuse_fs_lseek(struct fuse_fs *fs, const char *path, off_t off, int whence,
                    struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.lseek)
                return -ENOSYS;
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "lseek[%s] %llu %d\n",
                        file_info_string(fi, buf, sizeof(buf)),
                        (unsigned long long) off, whence);
        }
        return fs->op.lseek(path, off, whence, fi);
}
 
#ifdef HAVE_STATX
int fuse_fs_statx(struct fuse_fs *fs, const char *path, int flags, int mask,
                  struct statx *stxbuf, struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (fs->op.statx) {
                if (fs->debug) {
                        char buf[10];
 
                        fuse_log(FUSE_LOG_DEBUG, "statx[%s] %s %d %d\n",
                                file_info_string(fi, buf, sizeof(buf)), path,
                                flags, mask);
                }
                return fs->op.statx(path, flags, mask, stxbuf, fi);
        }
 
        return -ENOSYS;
}
#else
int fuse_fs_statx(struct fuse_fs *fs, const char *path, int flags, int mask,
                  struct statx *stxbuf, struct fuse_file_info *fi)
{
        (void)fs;
        (void)path;
        (void)flags;
        (void)mask;
        (void)stxbuf;
        (void)fi;
 
        return -ENOSYS;
}
#endif
 
static int is_open(struct fuse *f, fuse_ino_t dir, const char *name)
{
        struct node *node;
        int isopen = 0;
        pthread_mutex_lock(&f->lock);
        node = lookup_node(f, dir, name);
        if (node && node->open_count > 0)
                isopen = 1;
        pthread_mutex_unlock(&f->lock);
        return isopen;
}
 
static char *hidden_name(struct fuse *f, fuse_ino_t dir, const char *oldname,
                         char *newname, size_t bufsize)
{
        struct stat buf;
        struct node *node;
        struct node *newnode;
        char *newpath;
        int res;
        int failctr = 10;
 
        do {
                pthread_mutex_lock(&f->lock);
                node = lookup_node(f, dir, oldname);
                if (node == NULL) {
                        pthread_mutex_unlock(&f->lock);
                        return NULL;
                }
                do {
                        f->hidectr ++;
                        snprintf(newname, bufsize, ".fuse_hidden%08x%08x",
                                 (unsigned int) node->nodeid, f->hidectr);
                        newnode = lookup_node(f, dir, newname);
                } while(newnode);
 
                res = try_get_path(f, dir, newname, &newpath, NULL, false);
                pthread_mutex_unlock(&f->lock);
                if (res)
                        break;
 
                memset(&buf, 0, sizeof(buf));
                res = fuse_fs_getattr(f->fs, newpath, &buf, NULL);
                if (res == -ENOENT)
                        break;
                free(newpath);
                newpath = NULL;
        } while(res == 0 && --failctr);
 
        return newpath;
}
 
static int hide_node(struct fuse *f, const char *oldpath,
                     fuse_ino_t dir, const char *oldname)
{
        char newname[64];
        char *newpath;
        int err = -EBUSY;
 
        newpath = hidden_name(f, dir, oldname, newname, sizeof(newname));
        if (newpath) {
                err = fuse_fs_rename(f->fs, oldpath, newpath, 0);
                if (!err)
                        err = rename_node(f, dir, oldname, dir, newname, 1);
                free(newpath);
        }
        return err;
}
 
static int mtime_eq(const struct stat *stbuf, const struct timespec *ts)
{
        return stbuf->st_mtime == ts->tv_sec &&
                ST_MTIM_NSEC(stbuf) == ts->tv_nsec;
}
 
#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC CLOCK_REALTIME
#endif
 
static void curr_time(struct timespec *now)
{
        static clockid_t clockid = CLOCK_MONOTONIC;
        int res = clock_gettime(clockid, now);
        if (res == -1 && errno == EINVAL) {
                clockid = CLOCK_REALTIME;
                res = clock_gettime(clockid, now);
        }
        if (res == -1) {
                perror("fuse: clock_gettime");
                abort();
        }
}
 
static void update_stat(struct node *node, const struct stat *stbuf)
{
        if (node->cache_valid && (!mtime_eq(stbuf, &node->mtime) ||
                                  stbuf->st_size != node->size))
                node->cache_valid = 0;
        node->mtime.tv_sec = stbuf->st_mtime;
        node->mtime.tv_nsec = ST_MTIM_NSEC(stbuf);
        node->size = stbuf->st_size;
        curr_time(&node->stat_updated);
}
 
static int do_lookup(struct fuse *f, fuse_ino_t nodeid, const char *name,
                     struct fuse_entry_param *e)
{
        struct node *node;
 
        node = find_node(f, nodeid, name);
        if (node == NULL)
                return -ENOMEM;
 
        e->ino = node->nodeid;
        e->generation = node->generation;
        e->entry_timeout = f->conf.entry_timeout;
        e->attr_timeout = f->conf.attr_timeout;
        if (f->conf.auto_cache) {
                pthread_mutex_lock(&f->lock);
                update_stat(node, &e->attr);
                pthread_mutex_unlock(&f->lock);
        }
        set_stat(f, e->ino, &e->attr);
        return 0;
}
 
static int lookup_path(struct fuse *f, fuse_ino_t nodeid,
                       const char *name, const char *path,
                       struct fuse_entry_param *e, struct fuse_file_info *fi)
{
        int res;
 
        memset(e, 0, sizeof(struct fuse_entry_param));
        res = fuse_fs_getattr(f->fs, path, &e->attr, fi);
        if (res == 0) {
                res = do_lookup(f, nodeid, name, e);
                if (res == 0 && f->conf.debug) {
                        fuse_log(FUSE_LOG_DEBUG, "   NODEID: %llu\n",
                                (unsigned long long) e->ino);
                }
        }
        return res;
}
 
static struct fuse_context_i *fuse_get_context_internal(void)
{
        return (struct fuse_context_i *) pthread_getspecific(fuse_context_key);
}
 
static struct fuse_context_i *fuse_create_context(struct fuse *f)
{
        struct fuse_context_i *c = fuse_get_context_internal();
        if (c == NULL) {
                c = (struct fuse_context_i *)
                        calloc(1, sizeof(struct fuse_context_i));
                if (c == NULL) {
                        /* This is hard to deal with properly, so just
                           abort.  If memory is so low that the
                           context cannot be allocated, there's not
                           much hope for the filesystem anyway */
                        fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate thread specific data\n");
                        abort();
                }
                if (pthread_setspecific(fuse_context_key, c) != 0) {
                        fuse_log(FUSE_LOG_ERR, "fuse: failed to set thread specific data\n");
                        free(c);
                        abort();
                }
        } else {
                memset(c, 0, sizeof(*c));
        }
        c->ctx.fuse = f;
 
        return c;
}
 
static void fuse_freecontext(void *data)
{
        free(data);
}
 
static int fuse_create_context_key(void)
{
        int err = 0;
        pthread_mutex_lock(&fuse_context_lock);
        if (!fuse_context_ref) {
                err = pthread_key_create(&fuse_context_key, fuse_freecontext);
                if (err) {
                        fuse_log(FUSE_LOG_ERR, "fuse: failed to create thread specific key: %s\n",
                                strerror(err));
                        pthread_mutex_unlock(&fuse_context_lock);
                        return -1;
                }
        }
        fuse_context_ref++;
        pthread_mutex_unlock(&fuse_context_lock);
        return 0;
}
 
static void fuse_delete_context_key(void)
{
        pthread_mutex_lock(&fuse_context_lock);
        fuse_context_ref--;
        if (!fuse_context_ref) {
                free(pthread_getspecific(fuse_context_key));
                pthread_key_delete(fuse_context_key);
        }
        pthread_mutex_unlock(&fuse_context_lock);
}
 
static struct fuse *req_fuse_prepare(fuse_req_t req)
{
        struct fuse_context_i *c = fuse_create_context(req_fuse(req));
        const struct fuse_ctx *ctx = fuse_req_ctx(req);
        c->req = req;
        c->ctx.uid = ctx->uid;
        c->ctx.gid = ctx->gid;
        c->ctx.pid = ctx->pid;
        c->ctx.umask = ctx->umask;
        return c->ctx.fuse;
}
 
static inline void reply_err(fuse_req_t req, int err)
{
        /* fuse_reply_err() uses non-negated errno values */
        fuse_reply_err(req, -err);
}
 
static void reply_entry(fuse_req_t req, const struct fuse_entry_param *e,
                        int err)
{
        if (!err) {
                struct fuse *f = req_fuse(req);
                if (fuse_reply_entry(req, e) == -ENOENT) {
                        /* Skip forget for negative result */
                        if  (e->ino != 0)
                                forget_node(f, e->ino, 1);
                }
        } else
                reply_err(req, err);
}
 
void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn,
                  struct fuse_config *cfg)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.write_buf)
                fuse_unset_feature_flag(conn, FUSE_CAP_SPLICE_READ);
        if (!fs->op.lock)
                fuse_unset_feature_flag(conn, FUSE_CAP_POSIX_LOCKS);
        if (!fs->op.flock)
                fuse_unset_feature_flag(conn, FUSE_CAP_FLOCK_LOCKS);
        if (fs->op.init)
                fs->user_data = fs->op.init(conn, cfg);
}
 
static int fuse_init_intr_signal(int signum, int *installed);
 
static void fuse_lib_init(void *data, struct fuse_conn_info *conn)
{
        struct fuse *f = (struct fuse *) data;
 
        fuse_create_context(f);
        fuse_set_feature_flag(conn, FUSE_CAP_EXPORT_SUPPORT);
        fuse_fs_init(f->fs, conn, &f->conf);
 
        if (f->conf.intr) {
                if (fuse_init_intr_signal(f->conf.intr_signal,
                                &f->intr_installed) == -1)
                        fuse_log(FUSE_LOG_ERR, "fuse: failed to init interrupt signal\n");
        } else {
                /* Disable the receiving and processing of FUSE_INTERRUPT requests */
                conn->no_interrupt = 1;
        }
}
 
void fuse_fs_destroy(struct fuse_fs *fs)
{
        fuse_get_context()->private_data = fs->user_data;
        if (fs->op.destroy)
                fs->op.destroy(fs->user_data);
}
 
static void fuse_lib_destroy(void *data)
{
        struct fuse *f = (struct fuse *) data;
 
        fuse_create_context(f);
        fuse_fs_destroy(f->fs);
}
 
static void fuse_lib_lookup(fuse_req_t req, fuse_ino_t parent,
                            const char *name)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_entry_param e = { .ino = 0 }; /* invalid ino */
        char *path;
        int err;
        struct node *dot = NULL;
 
        if (name[0] == '.') {
                int len = strlen(name);
 
                if (len == 1 || (name[1] == '.' && len == 2)) {
                        pthread_mutex_lock(&f->lock);
                        if (len == 1) {
                                if (f->conf.debug)
                                        fuse_log(FUSE_LOG_DEBUG, "LOOKUP-DOT\n");
                                dot = get_node_nocheck(f, parent);
                                if (dot == NULL) {
                                        pthread_mutex_unlock(&f->lock);
                                        reply_entry(req, &e, -ESTALE);
                                        return;
                                }
                                dot->refctr++;
                        } else {
                                if (f->conf.debug)
                                        fuse_log(FUSE_LOG_DEBUG, "LOOKUP-DOTDOT\n");
                                parent = get_node(f, parent)->parent->nodeid;
                        }
                        pthread_mutex_unlock(&f->lock);
                        name = NULL;
                }
        }
 
        err = get_path_name(f, parent, name, &path);
        if (!err) {
                struct fuse_intr_data d;
                if (f->conf.debug)
                        fuse_log(FUSE_LOG_DEBUG, "LOOKUP %s\n", path);
                fuse_prepare_interrupt(f, req, &d);
                err = lookup_path(f, parent, name, path, &e, NULL);
                if (err == -ENOENT && f->conf.negative_timeout != 0.0) {
                        e.ino = 0;
                        e.entry_timeout = f->conf.negative_timeout;
                        err = 0;
                }
                fuse_finish_interrupt(f, req, &d);
                free_path(f, parent, path);
        }
        if (dot) {
                pthread_mutex_lock(&f->lock);
                unref_node(f, dot);
                pthread_mutex_unlock(&f->lock);
        }
        reply_entry(req, &e, err);
}
 
static void do_forget(struct fuse *f, fuse_ino_t ino, uint64_t nlookup)
{
        if (f->conf.debug)
                fuse_log(FUSE_LOG_DEBUG, "FORGET %llu/%llu\n", (unsigned long long)ino,
                        (unsigned long long) nlookup);
        forget_node(f, ino, nlookup);
}
 
static void fuse_lib_forget(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup)
{
        do_forget(req_fuse(req), ino, nlookup);
        fuse_reply_none(req);
}
 
static void fuse_lib_forget_multi(fuse_req_t req, size_t count,
                                  struct fuse_forget_data *forgets)
{
        struct fuse *f = req_fuse(req);
        size_t i;
 
        for (i = 0; i < count; i++)
                do_forget(f, forgets[i].ino, forgets[i].nlookup);
 
        fuse_reply_none(req);
}
 
 
static void fuse_lib_getattr(fuse_req_t req, fuse_ino_t ino,
                             struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct stat buf;
        char *path;
        int err;
 
        memset(&buf, 0, sizeof(buf));
 
        if (fi != NULL)
                err = get_path_nullok(f, ino, &path);
        else
                err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_getattr(f->fs, path, &buf, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        if (!err) {
                struct node *node;
 
                pthread_mutex_lock(&f->lock);
                node = get_node(f, ino);
                if (node->is_hidden && buf.st_nlink > 0)
                        buf.st_nlink--;
                if (f->conf.auto_cache)
                        update_stat(node, &buf);
                pthread_mutex_unlock(&f->lock);
                set_stat(f, ino, &buf);
                fuse_reply_attr(req, &buf, f->conf.attr_timeout);
        } else
                reply_err(req, err);
}
 
int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode,
                  struct fuse_file_info *fi)
{
        fuse_get_context()->private_data = fs->user_data;
        if (!fs->op.chmod)
                return -ENOSYS;
 
        if (fs->debug) {
                char buf[10];
 
                fuse_log(FUSE_LOG_DEBUG, "chmod[%s] %s %llo\n",
                        file_info_string(fi, buf, sizeof(buf)),
                        path, (unsigned long long) mode);
        }
        return fs->op.chmod(path, mode, fi);
}
 
static void fuse_lib_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
                             int valid, struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct stat buf;
        char *path;
        int err;
 
        memset(&buf, 0, sizeof(buf));
        if (fi != NULL)
                err = get_path_nullok(f, ino, &path);
        else
                err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = 0;
                if (!err && (valid & FUSE_SET_ATTR_MODE))
                        err = fuse_fs_chmod(f->fs, path, attr->st_mode, fi);
                if (!err && (valid & (FUSE_SET_ATTR_UID | FUSE_SET_ATTR_GID))) {
                        uid_t uid = (valid & FUSE_SET_ATTR_UID) ?
                                attr->st_uid : (uid_t) -1;
                        gid_t gid = (valid & FUSE_SET_ATTR_GID) ?
                                attr->st_gid : (gid_t) -1;
                        err = fuse_fs_chown(f->fs, path, uid, gid, fi);
                }
                if (!err && (valid & FUSE_SET_ATTR_SIZE)) {
                        err = fuse_fs_truncate(f->fs, path,
                                               attr->st_size, fi);
                }
#ifdef HAVE_UTIMENSAT
                if (!err &&
                    (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME))) {
                        struct timespec tv[2];
 
                        tv[0].tv_sec = 0;
                        tv[1].tv_sec = 0;
                        tv[0].tv_nsec = UTIME_OMIT;
                        tv[1].tv_nsec = UTIME_OMIT;
 
                        if (valid & FUSE_SET_ATTR_ATIME_NOW)
                                tv[0].tv_nsec = UTIME_NOW;
                        else if (valid & FUSE_SET_ATTR_ATIME)
                                tv[0] = attr->st_atim;
 
                        if (valid & FUSE_SET_ATTR_MTIME_NOW)
                                tv[1].tv_nsec = UTIME_NOW;
                        else if (valid & FUSE_SET_ATTR_MTIME)
                                tv[1] = attr->st_mtim;
 
                        err = fuse_fs_utimens(f->fs, path, tv, fi);
                } else
#endif
                if (!err &&
                    (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) ==
                    (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
                        struct timespec tv[2];
                        tv[0].tv_sec = attr->st_atime;
                        tv[0].tv_nsec = ST_ATIM_NSEC(attr);
                        tv[1].tv_sec = attr->st_mtime;
                        tv[1].tv_nsec = ST_MTIM_NSEC(attr);
                        err = fuse_fs_utimens(f->fs, path, tv, fi);
                }
                if (!err) {
                        err = fuse_fs_getattr(f->fs, path, &buf, fi);
                }
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        if (!err) {
                if (f->conf.auto_cache) {
                        pthread_mutex_lock(&f->lock);
                        update_stat(get_node(f, ino), &buf);
                        pthread_mutex_unlock(&f->lock);
                }
                set_stat(f, ino, &buf);
                fuse_reply_attr(req, &buf, f->conf.attr_timeout);
        } else
                reply_err(req, err);
}
 
static void fuse_lib_access(fuse_req_t req, fuse_ino_t ino, int mask)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_access(f->fs, path, mask);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_readlink(fuse_req_t req, fuse_ino_t ino)
{
        struct fuse *f = req_fuse_prepare(req);
        char linkname[PATH_MAX + 1];
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_readlink(f->fs, path, linkname, sizeof(linkname));
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        if (!err) {
                linkname[PATH_MAX] = '\0';
                fuse_reply_readlink(req, linkname);
        } else
                reply_err(req, err);
}
 
static void fuse_lib_mknod(fuse_req_t req, fuse_ino_t parent, const char *name,
                           mode_t mode, dev_t rdev)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_entry_param e;
        char *path;
        int err;
 
        err = get_path_name(f, parent, name, &path);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = -ENOSYS;
                if (S_ISREG(mode)) {
                        struct fuse_file_info fi;
 
                        memset(&fi, 0, sizeof(fi));
                        fi.flags = O_CREAT | O_EXCL | O_WRONLY;
                        err = fuse_fs_create(f->fs, path, mode, &fi);
                        if (!err) {
                                err = lookup_path(f, parent, name, path, &e,
                                                  &fi);
                                fuse_fs_release(f->fs, path, &fi);
                        }
                }
                if (err == -ENOSYS) {
                        err = fuse_fs_mknod(f->fs, path, mode, rdev);
                        if (!err)
                                err = lookup_path(f, parent, name, path, &e,
                                                  NULL);
                }
                fuse_finish_interrupt(f, req, &d);
                free_path(f, parent, path);
        }
        reply_entry(req, &e, err);
}
 
static void fuse_lib_mkdir(fuse_req_t req, fuse_ino_t parent, const char *name,
                           mode_t mode)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_entry_param e;
        char *path;
        int err;
 
        err = get_path_name(f, parent, name, &path);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_mkdir(f->fs, path, mode);
                if (!err)
                        err = lookup_path(f, parent, name, path, &e, NULL);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, parent, path);
        }
        reply_entry(req, &e, err);
}
 
static void fuse_lib_unlink(fuse_req_t req, fuse_ino_t parent,
                            const char *name)
{
        struct fuse *f = req_fuse_prepare(req);
        struct node *wnode;
        char *path;
        int err;
 
        err = get_path_wrlock(f, parent, name, &path, &wnode);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                if (!f->conf.hard_remove && is_open(f, parent, name)) {
                        err = hide_node(f, path, parent, name);
                        if (!err) {
                                /* we have hidden the node so now check again under a lock in case it is not used any more */
                                if (!is_open(f, parent, wnode->name)) {
                                        char *unlinkpath;
 
                                        /* get the hidden file path, to unlink it */
                                        if (try_get_path(f, wnode->nodeid, NULL, &unlinkpath, NULL, false) == 0) {
                                                err = fuse_fs_unlink(f->fs, unlinkpath);
                                                if (!err)
                                                        remove_node(f, parent, wnode->name);
                                                free(unlinkpath);
                                        }
                                }
                        }
                } else {
                        err = fuse_fs_unlink(f->fs, path);
                        if (!err)
                                remove_node(f, parent, name);
                }
                fuse_finish_interrupt(f, req, &d);
                free_path_wrlock(f, parent, wnode, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)
{
        struct fuse *f = req_fuse_prepare(req);
        struct node *wnode;
        char *path;
        int err;
 
        err = get_path_wrlock(f, parent, name, &path, &wnode);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_rmdir(f->fs, path);
                fuse_finish_interrupt(f, req, &d);
                if (!err)
                        remove_node(f, parent, name);
                free_path_wrlock(f, parent, wnode, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_symlink(fuse_req_t req, const char *linkname,
                             fuse_ino_t parent, const char *name)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_entry_param e;
        char *path;
        int err;
 
        err = get_path_name(f, parent, name, &path);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_symlink(f->fs, linkname, path);
                if (!err)
                        err = lookup_path(f, parent, name, path, &e, NULL);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, parent, path);
        }
        reply_entry(req, &e, err);
}
 
static void fuse_lib_rename(fuse_req_t req, fuse_ino_t olddir,
                            const char *oldname, fuse_ino_t newdir,
                            const char *newname, unsigned int flags)
{
        struct fuse *f = req_fuse_prepare(req);
        char *oldpath;
        char *newpath;
        struct node *wnode1;
        struct node *wnode2;
        int err;
 
        err = get_path2(f, olddir, oldname, newdir, newname,
                        &oldpath, &newpath, &wnode1, &wnode2);
        if (!err) {
                struct fuse_intr_data d;
                err = 0;
                fuse_prepare_interrupt(f, req, &d);
                if (!f->conf.hard_remove && !(flags & RENAME_EXCHANGE) &&
                    is_open(f, newdir, newname))
                        err = hide_node(f, newpath, newdir, newname);
                if (!err) {
                        err = fuse_fs_rename(f->fs, oldpath, newpath, flags);
                        if (!err) {
                                if (flags & RENAME_EXCHANGE) {
                                        err = exchange_node(f, olddir, oldname,
                                                            newdir, newname);
                                } else {
                                        err = rename_node(f, olddir, oldname,
                                                          newdir, newname, 0);
                                }
                        }
                }
                fuse_finish_interrupt(f, req, &d);
                free_path2(f, olddir, newdir, wnode1, wnode2, oldpath, newpath);
        }
        reply_err(req, err);
}
 
static void fuse_lib_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t newparent,
                          const char *newname)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_entry_param e;
        char *oldpath;
        char *newpath;
        int err;
 
        err = get_path2(f, ino, NULL, newparent, newname,
                        &oldpath, &newpath, NULL, NULL);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_link(f->fs, oldpath, newpath);
                if (!err)
                        err = lookup_path(f, newparent, newname, newpath,
                                          &e, NULL);
                fuse_finish_interrupt(f, req, &d);
                free_path2(f, ino, newparent, NULL, NULL, oldpath, newpath);
        }
        reply_entry(req, &e, err);
}
 
static void fuse_do_release(struct fuse *f, fuse_ino_t ino, const char *path,
                            struct fuse_file_info *fi)
{
        struct node *node;
        int unlink_hidden = 0;
 
        fuse_fs_release(f->fs, path, fi);
 
        pthread_mutex_lock(&f->lock);
        node = get_node(f, ino);
        assert(node->open_count > 0);
        --node->open_count;
        if (node->is_hidden && !node->open_count) {
                unlink_hidden = 1;
                node->is_hidden = 0;
        }
        pthread_mutex_unlock(&f->lock);
 
        if(unlink_hidden) {
                if (path) {
                        fuse_fs_unlink(f->fs, path);
                } else if (f->conf.nullpath_ok) {
                        char *unlinkpath;
 
                        if (get_path(f, ino, &unlinkpath) == 0)
                                fuse_fs_unlink(f->fs, unlinkpath);
 
                        free_path(f, ino, unlinkpath);
                }
        }
}
 
static void fuse_lib_create(fuse_req_t req, fuse_ino_t parent,
                            const char *name, mode_t mode,
                            struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        struct fuse_entry_param e;
        char *path;
        int err;
 
        err = get_path_name(f, parent, name, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_create(f->fs, path, mode, fi);
                if (!err) {
                        err = lookup_path(f, parent, name, path, &e, fi);
                        if (err)
                                fuse_fs_release(f->fs, path, fi);
                        else if (!S_ISREG(e.attr.st_mode)) {
                                err = -EIO;
                                fuse_fs_release(f->fs, path, fi);
                                forget_node(f, e.ino, 1);
                        } else {
                                if (f->conf.direct_io)
                                        fi->direct_io = 1;
                                if (f->conf.kernel_cache)
                                        fi->keep_cache = 1;
                                if (fi->direct_io &&
                                    f->conf.parallel_direct_writes)
                                        fi->parallel_direct_writes = 1;
                        }
                }
                fuse_finish_interrupt(f, req, &d);
        }
        if (!err) {
                pthread_mutex_lock(&f->lock);
                get_node(f, e.ino)->open_count++;
                pthread_mutex_unlock(&f->lock);
                if (fuse_reply_create(req, &e, fi) == -ENOENT) {
                        /* The open syscall was interrupted, so it
                           must be cancelled */
                        fuse_do_release(f, e.ino, path, fi);
                        forget_node(f, e.ino, 1);
                }
        } else {
                reply_err(req, err);
        }
 
        free_path(f, parent, path);
}
 
static double diff_timespec(const struct timespec *t1,
                            const struct timespec *t2)
{
        return (t1->tv_sec - t2->tv_sec) +
                ((double) t1->tv_nsec - (double) t2->tv_nsec) / 1000000000.0;
}
 
static void open_auto_cache(struct fuse *f, fuse_ino_t ino, const char *path,
                            struct fuse_file_info *fi)
{
        struct node *node;
 
        pthread_mutex_lock(&f->lock);
        node = get_node(f, ino);
        if (node->cache_valid) {
                struct timespec now;
 
                curr_time(&now);
                if (diff_timespec(&now, &node->stat_updated) >
                    f->conf.ac_attr_timeout) {
                        struct stat stbuf;
                        int err;
                        pthread_mutex_unlock(&f->lock);
                        err = fuse_fs_getattr(f->fs, path, &stbuf, fi);
                        pthread_mutex_lock(&f->lock);
                        if (!err)
                                update_stat(node, &stbuf);
                        else
                                node->cache_valid = 0;
                }
        }
        if (node->cache_valid)
                fi->keep_cache = 1;
 
        node->cache_valid = 1;
        pthread_mutex_unlock(&f->lock);
}
 
static void fuse_lib_open(fuse_req_t req, fuse_ino_t ino,
                          struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_open(f->fs, path, fi);
                if (!err) {
                        if (f->conf.direct_io)
                                fi->direct_io = 1;
                        if (f->conf.kernel_cache)
                                fi->keep_cache = 1;
 
                        if (f->conf.auto_cache)
                                open_auto_cache(f, ino, path, fi);
 
                        if (f->conf.no_rofd_flush &&
                            (fi->flags & O_ACCMODE) == O_RDONLY)
                                fi->noflush = 1;
 
                        if (fi->direct_io && f->conf.parallel_direct_writes)
                                fi->parallel_direct_writes = 1;
 
                }
                fuse_finish_interrupt(f, req, &d);
        }
        if (!err) {
                pthread_mutex_lock(&f->lock);
                get_node(f, ino)->open_count++;
                pthread_mutex_unlock(&f->lock);
                if (fuse_reply_open(req, fi) == -ENOENT) {
                        /* The open syscall was interrupted, so it
                           must be cancelled */
                        fuse_do_release(f, ino, path, fi);
                }
        } else
                reply_err(req, err);
 
        free_path(f, ino, path);
}
 
static void fuse_lib_read(fuse_req_t req, fuse_ino_t ino, size_t size,
                          off_t off, struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_bufvec *buf = NULL;
        char *path;
        int res;
 
        res = get_path_nullok(f, ino, &path);
        if (res == 0) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                res = fuse_fs_read_buf(f->fs, path, &buf, size, off, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
 
        if (res == 0)
                fuse_reply_data(req, buf, FUSE_BUF_SPLICE_MOVE);
        else
                reply_err(req, res);
 
        fuse_free_buf(buf);
}
 
static void fuse_lib_write_buf(fuse_req_t req, fuse_ino_t ino,
                               struct fuse_bufvec *buf, off_t off,
                               struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int res;
 
        res = get_path_nullok(f, ino, &path);
        if (res == 0) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                res = fuse_fs_write_buf(f->fs, path, buf, off, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
 
        if (res >= 0)
                fuse_reply_write(req, res);
        else
                reply_err(req, res);
}
 
static void fuse_lib_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
                           struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path_nullok(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
 
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_fsync(f->fs, path, datasync, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static struct fuse_dh *get_dirhandle(const struct fuse_file_info *llfi,
                                     struct fuse_file_info *fi)
{
        struct fuse_dh *dh = (struct fuse_dh *) (uintptr_t) llfi->fh;
        memset(fi, 0, sizeof(struct fuse_file_info));
        fi->fh = dh->fh;
        return dh;
}
 
static void fuse_lib_opendir(fuse_req_t req, fuse_ino_t ino,
                             struct fuse_file_info *llfi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        struct fuse_dh *dh;
        struct fuse_file_info fi;
        char *path;
        int err;
 
        dh = (struct fuse_dh *) malloc(sizeof(struct fuse_dh));
        if (dh == NULL) {
                reply_err(req, -ENOMEM);
                return;
        }
        memset(dh, 0, sizeof(struct fuse_dh));
        dh->fuse = f;
        dh->contents = NULL;
        dh->first = NULL;
        dh->len = 0;
        dh->filled = 0;
        dh->nodeid = ino;
        pthread_mutex_init(&dh->lock, NULL);
 
        llfi->fh = (uintptr_t) dh;
 
        memset(&fi, 0, sizeof(fi));
        fi.flags = llfi->flags;
 
        err = get_path(f, ino, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_opendir(f->fs, path, &fi);
                fuse_finish_interrupt(f, req, &d);
                dh->fh = fi.fh;
                llfi->cache_readdir = fi.cache_readdir;
                llfi->keep_cache = fi.keep_cache;
        }
        if (!err) {
                if (fuse_reply_open(req, llfi) == -ENOENT) {
                        /* The opendir syscall was interrupted, so it
                           must be cancelled */
                        fuse_fs_releasedir(f->fs, path, &fi);
                        pthread_mutex_destroy(&dh->lock);
                        free(dh);
                }
        } else {
                reply_err(req, err);
                pthread_mutex_destroy(&dh->lock);
                free(dh);
        }
        free_path(f, ino, path);
}
 
static int extend_contents(struct fuse_dh *dh, unsigned minsize)
{
        if (minsize > dh->size) {
                char *newptr;
                unsigned newsize = dh->size;
                if (!newsize)
                        newsize = 1024;
                while (newsize < minsize) {
                        if (newsize >= 0x80000000)
                                newsize = 0xffffffff;
                        else
                                newsize *= 2;
                }
 
                newptr = (char *) realloc(dh->contents, newsize);
                if (!newptr) {
                        dh->error = -ENOMEM;
                        return -1;
                }
                dh->contents = newptr;
                dh->size = newsize;
        }
        return 0;
}
 
static int fuse_add_direntry_to_dh(struct fuse_dh *dh, const char *name,
                                   struct stat *st, enum fuse_fill_dir_flags flags)
{
        struct fuse_direntry *de;
 
        de = malloc(sizeof(struct fuse_direntry));
        if (!de) {
                dh->error = -ENOMEM;
                return -1;
        }
        de->name = strdup(name);
        if (!de->name) {
                dh->error = -ENOMEM;
                free(de);
                return -1;
        }
        de->flags = flags;
        de->stat = *st;
        de->next = NULL;
 
        *dh->last = de;
        dh->last = &de->next;
 
        return 0;
}
 
static fuse_ino_t lookup_nodeid(struct fuse *f, fuse_ino_t parent,
                                const char *name)
{
        struct node *node;
        fuse_ino_t res = FUSE_UNKNOWN_INO;
 
        pthread_mutex_lock(&f->lock);
        node = lookup_node(f, parent, name);
        if (node)
                res = node->nodeid;
        pthread_mutex_unlock(&f->lock);
 
        return res;
}
 
static int fill_dir(void *dh_, const char *name, const struct stat *statp,
                    off_t off, enum fuse_fill_dir_flags flags)
{
        struct fuse_dh *dh = (struct fuse_dh *) dh_;
        struct stat stbuf;
 
        if ((flags & ~FUSE_FILL_DIR_PLUS) != 0) {
                dh->error = -EIO;
                return 1;
        }
 
        if (statp)
                stbuf = *statp;
        else {
                memset(&stbuf, 0, sizeof(stbuf));
                stbuf.st_ino = FUSE_UNKNOWN_INO;
        }
 
        if (!dh->fuse->conf.use_ino) {
                stbuf.st_ino = FUSE_UNKNOWN_INO;
                if (dh->fuse->conf.readdir_ino) {
                        stbuf.st_ino = (ino_t)
                                lookup_nodeid(dh->fuse, dh->nodeid, name);
                }
        }
 
        if (off) {
                size_t newlen;
 
                if (dh->filled) {
                        dh->error = -EIO;
                        return 1;
                }
 
                if (dh->first) {
                        dh->error = -EIO;
                        return 1;
                }
 
                if (extend_contents(dh, dh->needlen) == -1)
                        return 1;
 
                newlen = dh->len +
                        fuse_add_direntry(dh->req, dh->contents + dh->len,
                                          dh->needlen - dh->len, name,
                                          &stbuf, off);
                if (newlen > dh->needlen)
                        return 1;
 
                dh->len = newlen;
        } else {
                dh->filled = 1;
 
                if (fuse_add_direntry_to_dh(dh, name, &stbuf, flags) == -1)
                        return 1;
        }
        return 0;
}
 
static int is_dot_or_dotdot(const char *name)
{
        return name[0] == '.' && (name[1] == '\0' ||
                                  (name[1] == '.' && name[2] == '\0'));
}
 
static int fill_dir_plus(void *dh_, const char *name, const struct stat *statp,
                         off_t off, enum fuse_fill_dir_flags flags)
{
        struct fuse_dh *dh = (struct fuse_dh *) dh_;
        struct fuse_entry_param e = {
                /* ino=0 tells the kernel to ignore readdirplus stat info */
                .ino = 0,
        };
        struct fuse *f = dh->fuse;
        int res;
 
        if ((flags & ~FUSE_FILL_DIR_PLUS) != 0) {
                dh->error = -EIO;
                return 1;
        }
 
        if (statp && (flags & FUSE_FILL_DIR_PLUS)) {
                e.attr = *statp;
        }
 
        e.attr.st_ino = FUSE_UNKNOWN_INO;
        if (statp) {
                e.attr.st_mode = statp->st_mode;
                if (f->conf.use_ino)
                        e.attr.st_ino = statp->st_ino;
        }
        if (!f->conf.use_ino && f->conf.readdir_ino) {
                e.attr.st_ino = (ino_t)
                        lookup_nodeid(f, dh->nodeid, name);
        }
 
        if (off) {
                size_t newlen;
 
                if (dh->filled) {
                        dh->error = -EIO;
                        return 1;
                }
 
                if (dh->first) {
                        dh->error = -EIO;
                        return 1;
                }
                if (extend_contents(dh, dh->needlen) == -1)
                        return 1;
 
                if (statp && (flags & FUSE_FILL_DIR_PLUS)) {
                        if (!is_dot_or_dotdot(name)) {
                                res = do_lookup(f, dh->nodeid, name, &e);
                                if (res) {
                                        dh->error = res;
                                        return 1;
                                }
                        }
                }
 
                newlen = dh->len +
                        fuse_add_direntry_plus(dh->req, dh->contents + dh->len,
                                               dh->needlen - dh->len, name,
                                               &e, off);
                if (newlen > dh->needlen)
                        return 1;
                dh->len = newlen;
        } else {
                dh->filled = 1;
 
                if (fuse_add_direntry_to_dh(dh, name, &e.attr, flags) == -1)
                        return 1;
        }
 
        return 0;
}
 
static void free_direntries(struct fuse_direntry *de)
{
        while (de) {
                struct fuse_direntry *next = de->next;
                free(de->name);
                free(de);
                de = next;
        }
}
 
static int readdir_fill(struct fuse *f, fuse_req_t req, fuse_ino_t ino,
                        size_t size, off_t off, struct fuse_dh *dh,
                        struct fuse_file_info *fi,
                        enum fuse_readdir_flags flags)
{
        char *path;
        int err;
 
        if (f->fs->op.readdir)
                err = get_path_nullok(f, ino, &path);
        else
                err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_fill_dir_t filler = fill_dir;
 
                if (flags & FUSE_READDIR_PLUS)
                        filler = fill_dir_plus;
 
                free_direntries(dh->first);
                dh->first = NULL;
                dh->last = &dh->first;
                dh->len = 0;
                dh->error = 0;
                dh->needlen = size;
                dh->filled = 0;
                dh->req = req;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_readdir(f->fs, path, dh, filler, off, fi, flags);
                fuse_finish_interrupt(f, req, &d);
                dh->req = NULL;
                if (!err)
                        err = dh->error;
                if (err)
                        dh->filled = 0;
                free_path(f, ino, path);
        }
        return err;
}
 
static int readdir_fill_from_list(fuse_req_t req, struct fuse_dh *dh,
                                  off_t off, enum fuse_readdir_flags flags)
{
        off_t pos;
        struct fuse_direntry *de = dh->first;
        int res;
 
        dh->len = 0;
 
        if (extend_contents(dh, dh->needlen) == -1)
                return dh->error;
 
        for (pos = 0; pos < off; pos++) {
                if (!de)
                        break;
 
                de = de->next;
        }
        while (de) {
                char *p = dh->contents + dh->len;
                unsigned rem = dh->needlen - dh->len;
                unsigned thislen;
                unsigned newlen;
                pos++;
 
                if (flags & FUSE_READDIR_PLUS) {
                        struct fuse_entry_param e = {
                                .ino = 0,
                                .attr = de->stat,
                        };
 
                        if (de->flags & FUSE_FILL_DIR_PLUS &&
                            !is_dot_or_dotdot(de->name)) {
                                res = do_lookup(dh->fuse, dh->nodeid,
                                                de->name, &e);
                                if (res) {
                                        dh->error = res;
                                        return 1;
                                }
                        }
 
                        thislen = fuse_add_direntry_plus(req, p, rem,
                                                         de->name, &e, pos);
                } else {
                        thislen = fuse_add_direntry(req, p, rem,
                                                    de->name, &de->stat, pos);
                }
                newlen = dh->len + thislen;
                if (newlen > dh->needlen)
                        break;
                dh->len = newlen;
                de = de->next;
        }
        return 0;
}
 
static void fuse_readdir_common(fuse_req_t req, fuse_ino_t ino, size_t size,
                                off_t off, struct fuse_file_info *llfi,
                                enum fuse_readdir_flags flags)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_file_info fi;
        struct fuse_dh *dh = get_dirhandle(llfi, &fi);
        int err;
 
        pthread_mutex_lock(&dh->lock);
        /* According to SUS, directory contents need to be refreshed on
           rewinddir() */
        if (!off)
                dh->filled = 0;
 
        if (!dh->filled) {
                err = readdir_fill(f, req, ino, size, off, dh, &fi, flags);
                if (err) {
                        reply_err(req, err);
                        goto out;
                }
        }
        if (dh->filled) {
                dh->needlen = size;
                err = readdir_fill_from_list(req, dh, off, flags);
                if (err) {
                        reply_err(req, err);
                        goto out;
                }
        }
        fuse_reply_buf(req, dh->contents, dh->len);
out:
        pthread_mutex_unlock(&dh->lock);
}
 
static void fuse_lib_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
                             off_t off, struct fuse_file_info *llfi)
{
        fuse_readdir_common(req, ino, size, off, llfi, 0);
}
 
static void fuse_lib_readdirplus(fuse_req_t req, fuse_ino_t ino, size_t size,
                                  off_t off, struct fuse_file_info *llfi)
{
        fuse_readdir_common(req, ino, size, off, llfi, FUSE_READDIR_PLUS);
}
 
static void fuse_lib_releasedir(fuse_req_t req, fuse_ino_t ino,
                                struct fuse_file_info *llfi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        struct fuse_file_info fi;
        struct fuse_dh *dh = get_dirhandle(llfi, &fi);
        char *path;
 
        get_path_nullok(f, ino, &path);
 
        fuse_prepare_interrupt(f, req, &d);
        fuse_fs_releasedir(f->fs, path, &fi);
        fuse_finish_interrupt(f, req, &d);
        free_path(f, ino, path);
 
        pthread_mutex_lock(&dh->lock);
        pthread_mutex_unlock(&dh->lock);
        pthread_mutex_destroy(&dh->lock);
        free_direntries(dh->first);
        free(dh->contents);
        free(dh);
        reply_err(req, 0);
}
 
static void fuse_lib_fsyncdir(fuse_req_t req, fuse_ino_t ino, int datasync,
                              struct fuse_file_info *llfi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_file_info fi;
        char *path;
        int err;
 
        get_dirhandle(llfi, &fi);
 
        err = get_path_nullok(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_fsyncdir(f->fs, path, datasync, &fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_statfs(fuse_req_t req, fuse_ino_t ino)
{
        struct fuse *f = req_fuse_prepare(req);
        struct statvfs buf;
        char *path = NULL;
        int err = 0;
 
        memset(&buf, 0, sizeof(buf));
        if (ino)
                err = get_path(f, ino, &path);
 
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_statfs(f->fs, path ? path : "/", &buf);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
 
        if (!err)
                fuse_reply_statfs(req, &buf);
        else
                reply_err(req, err);
}
 
static void fuse_lib_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
                              const char *value, size_t size, int flags)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_setxattr(f->fs, path, name, value, size, flags);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static int common_getxattr(struct fuse *f, fuse_req_t req, fuse_ino_t ino,
                           const char *name, char *value, size_t size)
{
        int err;
        char *path;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_getxattr(f->fs, path, name, value, size);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        return err;
}
 
static void fuse_lib_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
                              size_t size)
{
        struct fuse *f = req_fuse_prepare(req);
        int res;
 
        if (size) {
                char *value = (char *) malloc(size);
                if (value == NULL) {
                        reply_err(req, -ENOMEM);
                        return;
                }
                res = common_getxattr(f, req, ino, name, value, size);
                if (res > 0)
                        fuse_reply_buf(req, value, res);
                else
                        reply_err(req, res);
                free(value);
        } else {
                res = common_getxattr(f, req, ino, name, NULL, 0);
                if (res >= 0)
                        fuse_reply_xattr(req, res);
                else
                        reply_err(req, res);
        }
}
 
static int common_listxattr(struct fuse *f, fuse_req_t req, fuse_ino_t ino,
                            char *list, size_t size)
{
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_listxattr(f->fs, path, list, size);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        return err;
}
 
static void fuse_lib_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size)
{
        struct fuse *f = req_fuse_prepare(req);
        int res;
 
        if (size) {
                char *list = (char *) malloc(size);
                if (list == NULL) {
                        reply_err(req, -ENOMEM);
                        return;
                }
                res = common_listxattr(f, req, ino, list, size);
                if (res > 0)
                        fuse_reply_buf(req, list, res);
                else
                        reply_err(req, res);
                free(list);
        } else {
                res = common_listxattr(f, req, ino, NULL, 0);
                if (res >= 0)
                        fuse_reply_xattr(req, res);
                else
                        reply_err(req, res);
        }
}
 
static void fuse_lib_removexattr(fuse_req_t req, fuse_ino_t ino,
                                 const char *name)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_removexattr(f->fs, path, name);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static struct lock *locks_conflict(struct node *node, const struct lock *lock)
{
        struct lock *l;
 
        for (l = node->locks; l; l = l->next)
                if (l->owner != lock->owner &&
                    lock->start <= l->end && l->start <= lock->end &&
                    (l->type == F_WRLCK || lock->type == F_WRLCK))
                        break;
 
        return l;
}
 
static void delete_lock(struct lock **lockp)
{
        struct lock *l = *lockp;
        *lockp = l->next;
        free(l);
}
 
static void insert_lock(struct lock **pos, struct lock *lock)
{
        lock->next = *pos;
        *pos = lock;
}
 
static int locks_insert(struct node *node, struct lock *lock)
{
        struct lock **lp;
        struct lock *newl1 = NULL;
        struct lock *newl2 = NULL;
 
        if (lock->type != F_UNLCK || lock->start != 0 ||
            lock->end != OFFSET_MAX) {
                newl1 = malloc(sizeof(struct lock));
                newl2 = malloc(sizeof(struct lock));
 
                if (!newl1 || !newl2) {
                        free(newl1);
                        free(newl2);
                        return -ENOLCK;
                }
        }
 
        for (lp = &node->locks; *lp;) {
                struct lock *l = *lp;
                if (l->owner != lock->owner)
                        goto skip;
 
                if (lock->type == l->type) {
                        if (l->end < lock->start - 1)
                                goto skip;
                        if (lock->end < l->start - 1)
                                break;
                        if (l->start <= lock->start && lock->end <= l->end)
                                goto out;
                        if (l->start < lock->start)
                                lock->start = l->start;
                        if (lock->end < l->end)
                                lock->end = l->end;
                        goto delete;
                } else {
                        if (l->end < lock->start)
                                goto skip;
                        if (lock->end < l->start)
                                break;
                        if (lock->start <= l->start && l->end <= lock->end)
                                goto delete;
                        if (l->end <= lock->end) {
                                l->end = lock->start - 1;
                                goto skip;
                        }
                        if (lock->start <= l->start) {
                                l->start = lock->end + 1;
                                break;
                        }
                        *newl2 = *l;
                        newl2->start = lock->end + 1;
                        l->end = lock->start - 1;
                        insert_lock(&l->next, newl2);
                        newl2 = NULL;
                }
        skip:
                lp = &l->next;
                continue;
 
        delete:
                delete_lock(lp);
        }
        if (lock->type != F_UNLCK) {
                *newl1 = *lock;
                insert_lock(lp, newl1);
                newl1 = NULL;
        }
out:
        free(newl1);
        free(newl2);
        return 0;
}
 
static void flock_to_lock(struct flock *flock, struct lock *lock)
{
        memset(lock, 0, sizeof(struct lock));
        lock->type = flock->l_type;
        lock->start = flock->l_start;
        lock->end =
                flock->l_len ? flock->l_start + flock->l_len - 1 : OFFSET_MAX;
        lock->pid = flock->l_pid;
}
 
static void lock_to_flock(struct lock *lock, struct flock *flock)
{
        flock->l_type = lock->type;
        flock->l_start = lock->start;
        flock->l_len =
                (lock->end == OFFSET_MAX) ? 0 : lock->end - lock->start + 1;
        flock->l_pid = lock->pid;
}
 
static int fuse_flush_common(struct fuse *f, fuse_req_t req, fuse_ino_t ino,
                             const char *path, struct fuse_file_info *fi)
{
        struct fuse_intr_data d;
        struct flock lock;
        struct lock l;
        int err;
        int errlock;
 
        fuse_prepare_interrupt(f, req, &d);
        memset(&lock, 0, sizeof(lock));
        lock.l_type = F_UNLCK;
        lock.l_whence = SEEK_SET;
        err = fuse_fs_flush(f->fs, path, fi);
        errlock = fuse_fs_lock(f->fs, path, fi, F_SETLK, &lock);
        fuse_finish_interrupt(f, req, &d);
 
        if (errlock != -ENOSYS) {
                flock_to_lock(&lock, &l);
                l.owner = fi->lock_owner;
                pthread_mutex_lock(&f->lock);
                locks_insert(get_node(f, ino), &l);
                pthread_mutex_unlock(&f->lock);
 
                /* if op.lock() is defined FLUSH is needed regardless
                   of op.flush() */
                if (err == -ENOSYS)
                        err = 0;
        }
        return err;
}
 
static void fuse_lib_release(fuse_req_t req, fuse_ino_t ino,
                             struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err = 0;
 
        get_path_nullok(f, ino, &path);
        if (fi->flush) {
                err = fuse_flush_common(f, req, ino, path, fi);
                if (err == -ENOSYS)
                        err = 0;
        }
 
        fuse_prepare_interrupt(f, req, &d);
        fuse_do_release(f, ino, path, fi);
        fuse_finish_interrupt(f, req, &d);
        free_path(f, ino, path);
 
        reply_err(req, err);
}
 
static void fuse_lib_flush(fuse_req_t req, fuse_ino_t ino,
                           struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        get_path_nullok(f, ino, &path);
        err = fuse_flush_common(f, req, ino, path, fi);
        free_path(f, ino, path);
 
        reply_err(req, err);
}
 
static int fuse_lock_common(fuse_req_t req, fuse_ino_t ino,
                            struct fuse_file_info *fi, struct flock *lock,
                            int cmd)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path_nullok(f, ino, &path);
        if (!err) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_lock(f->fs, path, fi, cmd, lock);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        return err;
}
 
static void fuse_lib_getlk(fuse_req_t req, fuse_ino_t ino,
                           struct fuse_file_info *fi, struct flock *lock)
{
        int err;
        struct lock l;
        struct lock *conflict;
        struct fuse *f = req_fuse(req);
 
        flock_to_lock(lock, &l);
        l.owner = fi->lock_owner;
        pthread_mutex_lock(&f->lock);
        conflict = locks_conflict(get_node(f, ino), &l);
        if (conflict)
                lock_to_flock(conflict, lock);
        pthread_mutex_unlock(&f->lock);
        if (!conflict)
                err = fuse_lock_common(req, ino, fi, lock, F_GETLK);
        else
                err = 0;
 
        if (!err)
                fuse_reply_lock(req, lock);
        else
                reply_err(req, err);
}
 
static void fuse_lib_setlk(fuse_req_t req, fuse_ino_t ino,
                           struct fuse_file_info *fi, struct flock *lock,
                           int sleep)
{
        int err = fuse_lock_common(req, ino, fi, lock,
                                   sleep ? F_SETLKW : F_SETLK);
        if (!err) {
                struct fuse *f = req_fuse(req);
                struct lock l;
                flock_to_lock(lock, &l);
                l.owner = fi->lock_owner;
                pthread_mutex_lock(&f->lock);
                locks_insert(get_node(f, ino), &l);
                pthread_mutex_unlock(&f->lock);
        }
        reply_err(req, err);
}
 
static void fuse_lib_flock(fuse_req_t req, fuse_ino_t ino,
                           struct fuse_file_info *fi, int op)
{
        struct fuse *f = req_fuse_prepare(req);
        char *path;
        int err;
 
        err = get_path_nullok(f, ino, &path);
        if (err == 0) {
                struct fuse_intr_data d;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_flock(f->fs, path, fi, op);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_bmap(fuse_req_t req, fuse_ino_t ino, size_t blocksize,
                          uint64_t idx)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err;
 
        err = get_path(f, ino, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_bmap(f->fs, path, blocksize, &idx);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        if (!err)
                fuse_reply_bmap(req, idx);
        else
                reply_err(req, err);
}
 
static void fuse_lib_ioctl(fuse_req_t req, fuse_ino_t ino, unsigned int cmd,
                           void *arg, struct fuse_file_info *llfi,
                           unsigned int flags, const void *in_buf,
                           size_t in_bufsz, size_t out_bufsz)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        struct fuse_file_info fi;
        char *path, *out_buf = NULL;
        int err;
 
        err = -EPERM;
        if (flags & FUSE_IOCTL_UNRESTRICTED)
                goto err;
 
        if (flags & FUSE_IOCTL_DIR)
                get_dirhandle(llfi, &fi);
        else
                fi = *llfi;
 
        if (out_bufsz) {
                err = -ENOMEM;
                out_buf = malloc(out_bufsz);
                if (!out_buf)
                        goto err;
        }
 
        assert(!in_bufsz || !out_bufsz || in_bufsz == out_bufsz);
        if (out_buf && in_bufsz)
                memcpy(out_buf, in_buf, in_bufsz);
 
        err = get_path_nullok(f, ino, &path);
        if (err)
                goto err;
 
        fuse_prepare_interrupt(f, req, &d);
 
        err = fuse_fs_ioctl(f->fs, path, cmd, arg, &fi, flags,
                            out_buf ? out_buf : (void *)in_buf);
 
        fuse_finish_interrupt(f, req, &d);
        free_path(f, ino, path);
 
        if (err < 0)
                goto err;
        fuse_reply_ioctl(req, err, out_buf, out_bufsz);
        goto out;
err:
        reply_err(req, err);
out:
        free(out_buf);
}
 
static void fuse_lib_poll(fuse_req_t req, fuse_ino_t ino,
                          struct fuse_file_info *fi, struct fuse_pollhandle *ph)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err;
        unsigned revents = 0;
 
        err = get_path_nullok(f, ino, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_poll(f->fs, path, fi, ph, &revents);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        } else {
                fuse_pollhandle_destroy(ph);
        }
        if (!err)
                fuse_reply_poll(req, revents);
        else
                reply_err(req, err);
}
 
static void fuse_lib_fallocate(fuse_req_t req, fuse_ino_t ino, int mode,
                off_t offset, off_t length, struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err;
 
        err = get_path_nullok(f, ino, &path);
        if (!err) {
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_fallocate(f->fs, path, mode, offset, length, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        reply_err(req, err);
}
 
static void fuse_lib_copy_file_range(fuse_req_t req, fuse_ino_t nodeid_in,
                                     off_t off_in, struct fuse_file_info *fi_in,
                                     fuse_ino_t nodeid_out, off_t off_out,
                                     struct fuse_file_info *fi_out, size_t len,
                                     int flags)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path_in, *path_out;
        int err;
        ssize_t res;
 
        err = get_path_nullok(f, nodeid_in, &path_in);
        if (err) {
                reply_err(req, err);
                return;
        }
 
        err = get_path_nullok(f, nodeid_out, &path_out);
        if (err) {
                free_path(f, nodeid_in, path_in);
                reply_err(req, err);
                return;
        }
 
        fuse_prepare_interrupt(f, req, &d);
        res = fuse_fs_copy_file_range(f->fs, path_in, fi_in, off_in, path_out,
                                      fi_out, off_out, len, flags);
        fuse_finish_interrupt(f, req, &d);
 
        if (res >= 0)
                fuse_reply_write(req, res);
        else
                reply_err(req, res);
 
        free_path(f, nodeid_in, path_in);
        free_path(f, nodeid_out, path_out);
}
 
static void fuse_lib_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
                           struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct fuse_intr_data d;
        char *path;
        int err;
        off_t res;
 
        err = get_path(f, ino, &path);
        if (err) {
                reply_err(req, err);
                return;
        }
 
        fuse_prepare_interrupt(f, req, &d);
        res = fuse_fs_lseek(f->fs, path, off, whence, fi);
        fuse_finish_interrupt(f, req, &d);
        free_path(f, ino, path);
        if (res >= 0)
                fuse_reply_lseek(req, res);
        else
                reply_err(req, res);
}
 
#ifdef HAVE_STATX
static void fuse_lib_statx(fuse_req_t req, fuse_ino_t ino, int flags, int mask,
                           struct fuse_file_info *fi)
{
        struct fuse *f = req_fuse_prepare(req);
        struct statx stxbuf;
        char *path;
        int err;
 
        memset(&stxbuf, 0, sizeof(stxbuf));
 
        if (fi != NULL)
                err = get_path_nullok(f, ino, &path);
        else
                err = get_path(f, ino, &path);
 
        if (!err) {
                struct fuse_intr_data d;
 
                if (!path)
                        flags |= AT_EMPTY_PATH;
                fuse_prepare_interrupt(f, req, &d);
                err = fuse_fs_statx(f->fs, path, flags, mask, &stxbuf, fi);
                fuse_finish_interrupt(f, req, &d);
                free_path(f, ino, path);
        }
        if (!err) {
                struct node *node;
 
                pthread_mutex_lock(&f->lock);
                node = get_node(f, ino);
                if (node->is_hidden && stxbuf.stx_nlink > 0)
                        stxbuf.stx_nlink--;
                if (f->conf.auto_cache) {
                        struct stat stbuf;
 
                        stbuf.st_mtime = stxbuf.stx_mtime.tv_sec;
                        ST_MTIM_NSEC_SET(&stbuf, stxbuf.stx_mtime.tv_nsec);
                        stbuf.st_size = stxbuf.stx_size;
                        update_stat(node, &stbuf);
                }
                pthread_mutex_unlock(&f->lock);
                set_statx(f, ino, &stxbuf);
                fuse_reply_statx(req, 0, &stxbuf, f->conf.attr_timeout);
        } else
                reply_err(req, err);
}
#endif
 
static int clean_delay(struct fuse *f)
{
        /*
         * This is calculating the delay between clean runs.  To
         * reduce the number of cleans we are doing them 10 times
         * within the remember window.
         */
        int min_sleep = 60;
        int max_sleep = 3600;
        int sleep_time = f->conf.remember / 10;
 
        if (sleep_time > max_sleep)
                return max_sleep;
        if (sleep_time < min_sleep)
                return min_sleep;
        return sleep_time;
}
 
int fuse_clean_cache(struct fuse *f)
{
        struct node_lru *lnode;
        struct list_head *curr, *next;
        struct node *node;
        struct timespec now;
 
        pthread_mutex_lock(&f->lock);
 
        curr_time(&now);
 
        for (curr = f->lru_table.next; curr != &f->lru_table; curr = next) {
                double age;
 
                next = curr->next;
                lnode = list_entry(curr, struct node_lru, lru);
                node = &lnode->node;
 
                age = diff_timespec(&now, &lnode->forget_time);
                if (age <= f->conf.remember)
                        break;
 
                assert(node->nlookup == 1);
 
                /* Don't forget active directories */
                if (node->refctr > 1)
                        continue;
 
                node->nlookup = 0;
                unhash_name(f, node);
                unref_node(f, node);
        }
        pthread_mutex_unlock(&f->lock);
 
        return clean_delay(f);
}
 
static struct fuse_lowlevel_ops fuse_path_ops = {
        .init = fuse_lib_init,
        .destroy = fuse_lib_destroy,
        .lookup = fuse_lib_lookup,
        .forget = fuse_lib_forget,
        .forget_multi = fuse_lib_forget_multi,
        .getattr = fuse_lib_getattr,
        .setattr = fuse_lib_setattr,
        .access = fuse_lib_access,
        .readlink = fuse_lib_readlink,
        .mknod = fuse_lib_mknod,
        .mkdir = fuse_lib_mkdir,
        .unlink = fuse_lib_unlink,
        .rmdir = fuse_lib_rmdir,
        .symlink = fuse_lib_symlink,
        .rename = fuse_lib_rename,
        .link = fuse_lib_link,
        .create = fuse_lib_create,
        .open = fuse_lib_open,
        .read = fuse_lib_read,
        .write_buf = fuse_lib_write_buf,
        .flush = fuse_lib_flush,
        .release = fuse_lib_release,
        .fsync = fuse_lib_fsync,
        .opendir = fuse_lib_opendir,
        .readdir = fuse_lib_readdir,
        .readdirplus = fuse_lib_readdirplus,
        .releasedir = fuse_lib_releasedir,
        .fsyncdir = fuse_lib_fsyncdir,
        .statfs = fuse_lib_statfs,
        .setxattr = fuse_lib_setxattr,
        .getxattr = fuse_lib_getxattr,
        .listxattr = fuse_lib_listxattr,
        .removexattr = fuse_lib_removexattr,
        .getlk = fuse_lib_getlk,
        .setlk = fuse_lib_setlk,
        .flock = fuse_lib_flock,
        .bmap = fuse_lib_bmap,
        .ioctl = fuse_lib_ioctl,
        .poll = fuse_lib_poll,
        .fallocate = fuse_lib_fallocate,
        .copy_file_range = fuse_lib_copy_file_range,
        .lseek = fuse_lib_lseek,
#ifdef HAVE_STATX
        .statx = fuse_lib_statx,
#endif
};
 
int fuse_notify_poll(struct fuse_pollhandle *ph)
{
        return fuse_lowlevel_notify_poll(ph);
}
 
struct fuse_session *fuse_get_session(struct fuse *f)
{
        return f->se;
}
 
static int fuse_session_loop_remember(struct fuse *f)
{
        struct fuse_session *se = f->se;
        int res = 0;
        struct timespec now;
        time_t next_clean;
        struct pollfd fds = {
                .fd = se->fd,
                .events = POLLIN
        };
        struct fuse_buf fbuf = {
                .mem = NULL,
        };
 
        curr_time(&now);
        next_clean = now.tv_sec;
        while (!fuse_session_exited(se)) {
                unsigned timeout;
 
                curr_time(&now);
                if (now.tv_sec < next_clean)
                        timeout = next_clean - now.tv_sec;
                else
                        timeout = 0;
 
                res = poll(&fds, 1, timeout * 1000);
                if (res == -1) {
                        if (errno == EINTR)
                                continue;
                        else
                                break;
                } else if (res > 0) {
                        res = fuse_session_receive_buf_internal(se, &fbuf,
                                                                NULL);
                        if (res == -EINTR)
                                continue;
                        if (res <= 0)
                                break;
 
                        fuse_session_process_buf_internal(se, &fbuf, NULL);
                } else {
                        timeout = fuse_clean_cache(f);
                        curr_time(&now);
                        next_clean = now.tv_sec + timeout;
                }
        }
 
        fuse_buf_free(&fbuf);
        return res < 0 ? -1 : 0;
}
 
int fuse_loop(struct fuse *f)
{
        if (!f)
                return -1;
 
        if (lru_enabled(f))
                return fuse_session_loop_remember(f);
 
        return fuse_session_loop(f->se);
}
 
FUSE_SYMVER("fuse_loop_mt_312", "fuse_loop_mt@@FUSE_3.12")
int fuse_loop_mt_312(struct fuse *f, struct fuse_loop_config *config)
{
        if (f == NULL)
                return -1;
 
        int res = fuse_start_cleanup_thread(f);
        if (res)
                return -1;
 
        res = fuse_session_loop_mt_312(fuse_get_session(f), config);
        fuse_stop_cleanup_thread(f);
        return res;
}
 
int fuse_loop_mt_32(struct fuse *f, struct fuse_loop_config_v1 *config_v1);
FUSE_SYMVER("fuse_loop_mt_32", "fuse_loop_mt@FUSE_3.2")
int fuse_loop_mt_32(struct fuse *f, struct fuse_loop_config_v1 *config_v1)
{
        struct fuse_loop_config *config = fuse_loop_cfg_create();
        if (config == NULL)
                return ENOMEM;
 
        fuse_loop_cfg_convert(config, config_v1);
 
        int res = fuse_loop_mt_312(f, config);
 
        fuse_loop_cfg_destroy(config);
 
        return res;
}
 
int fuse_loop_mt_31(struct fuse *f, int clone_fd);
FUSE_SYMVER("fuse_loop_mt_31", "fuse_loop_mt@FUSE_3.0")
int fuse_loop_mt_31(struct fuse *f, int clone_fd)
{
        int err;
        struct fuse_loop_config *config = fuse_loop_cfg_create();
 
        if (config == NULL)
                return ENOMEM;
 
        fuse_loop_cfg_set_clone_fd(config, clone_fd);
 
        err = fuse_loop_mt_312(f, config);
 
        fuse_loop_cfg_destroy(config);
 
        return err;
}
 
void fuse_exit(struct fuse *f)
{
        fuse_session_exit(f->se);
}
 
struct fuse_context *fuse_get_context(void)
{
        struct fuse_context_i *c = fuse_get_context_internal();
 
        if (c)
                return &c->ctx;
        else
                return NULL;
}
 
int fuse_getgroups(int size, gid_t list[])
{
        struct fuse_context_i *c = fuse_get_context_internal();
        if (!c)
                return -EINVAL;
 
        return fuse_req_getgroups(c->req, size, list);
}
 
int fuse_interrupted(void)
{
        struct fuse_context_i *c = fuse_get_context_internal();
 
        if (c)
                return fuse_req_interrupted(c->req);
        else
                return 0;
}
 
int fuse_invalidate_path(struct fuse *f, const char *path) {
        fuse_ino_t ino;
        int err = lookup_path_in_cache(f, path, &ino);
        if (err) {
                return err;
        }
 
        return fuse_lowlevel_notify_inval_inode(f->se, ino, 0, 0);
}
 
#define FUSE_LIB_OPT(t, p, v) { t, offsetof(struct fuse_config, p), v }
 
static const struct fuse_opt fuse_lib_opts[] = {
        FUSE_OPT_KEY("debug",                 FUSE_OPT_KEY_KEEP),
        FUSE_OPT_KEY("-d",                    FUSE_OPT_KEY_KEEP),
        FUSE_LIB_OPT("debug",                 debug, 1),
        FUSE_LIB_OPT("-d",                    debug, 1),
        FUSE_LIB_OPT("kernel_cache",          kernel_cache, 1),
        FUSE_LIB_OPT("auto_cache",            auto_cache, 1),
        FUSE_LIB_OPT("noauto_cache",          auto_cache, 0),
        FUSE_LIB_OPT("no_rofd_flush",         no_rofd_flush, 1),
        FUSE_LIB_OPT("umask=",                set_mode, 1),
        FUSE_LIB_OPT("umask=%o",              umask, 0),
        FUSE_LIB_OPT("fmask=",                set_mode, 1),
        FUSE_LIB_OPT("fmask=%o",              fmask, 0),
        FUSE_LIB_OPT("dmask=",                set_mode, 1),
        FUSE_LIB_OPT("dmask=%o",              dmask, 0),
        FUSE_LIB_OPT("uid=",                  set_uid, 1),
        FUSE_LIB_OPT("uid=%d",                uid, 0),
        FUSE_LIB_OPT("gid=",                  set_gid, 1),
        FUSE_LIB_OPT("gid=%d",                gid, 0),
        FUSE_LIB_OPT("entry_timeout=%lf",     entry_timeout, 0),
        FUSE_LIB_OPT("attr_timeout=%lf",      attr_timeout, 0),
        FUSE_LIB_OPT("ac_attr_timeout=%lf",   ac_attr_timeout, 0),
        FUSE_LIB_OPT("ac_attr_timeout=",      ac_attr_timeout_set, 1),
        FUSE_LIB_OPT("negative_timeout=%lf",  negative_timeout, 0),
        FUSE_LIB_OPT("noforget",              remember, -1),
        FUSE_LIB_OPT("remember=%u",           remember, 0),
        FUSE_LIB_OPT("modules=%s",            modules, 0),
        FUSE_LIB_OPT("parallel_direct_write=%d", parallel_direct_writes, 0),
        FUSE_OPT_END
};
 
static int fuse_lib_opt_proc(void *data, const char *arg, int key,
                             struct fuse_args *outargs)
{
        (void) arg; (void) outargs; (void) data; (void) key;
 
        /* Pass through unknown options */
        return 1;
}
 
 
static const struct fuse_opt fuse_help_opts[] = {
        FUSE_LIB_OPT("modules=%s", modules, 1),
        FUSE_OPT_KEY("modules=%s", FUSE_OPT_KEY_KEEP),
        FUSE_OPT_END
};
 
static void print_module_help(const char *name,
                              fuse_module_factory_t *fac)
{
        struct fuse_args a = FUSE_ARGS_INIT(0, NULL);
        if (fuse_opt_add_arg(&a, "") == -1 ||
            fuse_opt_add_arg(&a, "-h") == -1) {
                fuse_opt_free_args(&a);
                return;
        }
        printf("\nOptions for %s module:\n", name);
        (*fac)(&a, NULL);
        fuse_opt_free_args(&a);
}
 
void fuse_lib_help(struct fuse_args *args)
{
        /* These are not all options, but only the ones that
           may be of interest to an end-user */
        printf(
"    -o kernel_cache        cache files in kernel\n"
"    -o [no]auto_cache      enable caching based on modification times (off)\n"
"    -o no_rofd_flush       disable flushing of read-only fd on close (off)\n"
"    -o umask=M             set file permissions (octal)\n"
"    -o fmask=M             set file permissions (octal)\n"
"    -o dmask=M             set dir  permissions (octal)\n"
"    -o uid=N               set file owner\n"
"    -o gid=N               set file group\n"
"    -o entry_timeout=T     cache timeout for names (1.0s)\n"
"    -o negative_timeout=T  cache timeout for deleted names (0.0s)\n"
"    -o attr_timeout=T      cache timeout for attributes (1.0s)\n"
"    -o ac_attr_timeout=T   auto cache timeout for attributes (attr_timeout)\n"
"    -o noforget            never forget cached inodes\n"
"    -o remember=T          remember cached inodes for T seconds (0s)\n"
"    -o modules=M1[:M2...]  names of modules to push onto filesystem stack\n");
 
 
        /* Print low-level help */
        fuse_lowlevel_help();
 
        /* Print help for builtin modules */
        print_module_help("subdir", &fuse_module_subdir_factory);
#ifdef HAVE_ICONV
        print_module_help("iconv", &fuse_module_iconv_factory);
#endif
 
        /* Parse command line options in case we need to
           activate more modules */
        struct fuse_config conf = { .modules = NULL };
        if (fuse_opt_parse(args, &conf, fuse_help_opts,
                           fuse_lib_opt_proc) == -1
            || !conf.modules)
                return;
 
        char *module;
        char *next;
        struct fuse_module *m;
 
        // Iterate over all modules
        for (module = conf.modules; module; module = next) {
                char *p;
                for (p = module; *p && *p != ':'; p++);
                next = *p ? p + 1 : NULL;
                *p = '\0';
 
                m = fuse_get_module(module);
                if (m)
                        print_module_help(module, &m->factory);
        }
}
 
static int fuse_init_intr_signal(int signum, int *installed)
{
        struct sigaction old_sa;
 
        if (sigaction(signum, NULL, &old_sa) == -1) {
                perror("fuse: cannot get old signal handler");
                return -1;
        }
 
        if (old_sa.sa_handler == SIG_DFL) {
                struct sigaction sa;
 
                memset(&sa, 0, sizeof(struct sigaction));
                sa.sa_handler = fuse_intr_sighandler;
                sigemptyset(&sa.sa_mask);
 
                if (sigaction(signum, &sa, NULL) == -1) {
                        perror("fuse: cannot set interrupt signal handler");
                        return -1;
                }
                *installed = 1;
        }
        return 0;
}
 
static void fuse_restore_intr_signal(int signum)
{
        struct sigaction sa;
 
        memset(&sa, 0, sizeof(struct sigaction));
        sa.sa_handler = SIG_DFL;
        sigaction(signum, &sa, NULL);
}
 
 
static int fuse_push_module(struct fuse *f, const char *module,
                            struct fuse_args *args)
{
        struct fuse_fs *fs[2] = { f->fs, NULL };
        struct fuse_fs *newfs;
        struct fuse_module *m = fuse_get_module(module);
 
        if (!m)
                return -1;
 
        newfs = m->factory(args, fs);
        if (!newfs) {
                fuse_put_module(m);
                return -1;
        }
        f->fs = newfs;
        return 0;
}
 
struct fuse_fs *fuse_fs_new(const struct fuse_operations *op, size_t op_size,
                            void *user_data)
{
        struct fuse_fs *fs;
 
        if (sizeof(struct fuse_operations) < op_size) {
                fuse_log(FUSE_LOG_ERR, "fuse: warning: library too old, some operations may not not work\n");
                op_size = sizeof(struct fuse_operations);
        }
 
        fs = (struct fuse_fs *) calloc(1, sizeof(struct fuse_fs));
        if (!fs) {
                fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate fuse_fs object\n");
                return NULL;
        }
 
        fs->user_data = user_data;
        if (op)
                memcpy(&fs->op, op, op_size);
        return fs;
}
 
static int node_table_init(struct node_table *t)
{
        t->size = NODE_TABLE_MIN_SIZE;
        t->array = (struct node **) calloc(1, sizeof(struct node *) * t->size);
        if (t->array == NULL) {
                fuse_log(FUSE_LOG_ERR, "fuse: memory allocation failed\n");
                return -1;
        }
        t->use = 0;
        t->split = 0;
 
        return 0;
}
 
static void *fuse_prune_nodes(void *fuse)
{
        struct fuse *f = fuse;
        int sleep_time;
 
        fuse_set_thread_name("fuse_prune_nodes");
 
        while(1) {
                sleep_time = fuse_clean_cache(f);
                sleep(sleep_time);
        }
        return NULL;
}
 
int fuse_start_cleanup_thread(struct fuse *f)
{
        if (lru_enabled(f))
                return fuse_start_thread(&f->prune_thread, fuse_prune_nodes, f);
 
        return 0;
}
 
void fuse_stop_cleanup_thread(struct fuse *f)
{
        if (lru_enabled(f)) {
                pthread_mutex_lock(&f->lock);
                pthread_cancel(f->prune_thread);
                pthread_mutex_unlock(&f->lock);
                pthread_join(f->prune_thread, NULL);
        }
}
 
/*
 * Not supposed to be called directly, but supposed to be called
 * through the fuse_new macro
 */
struct fuse *_fuse_new_31(struct fuse_args *args,
                          const struct fuse_operations *op, size_t op_size,
                          struct libfuse_version *version, void *user_data)
{
        struct fuse *f;
        struct node *root;
        struct fuse_fs *fs;
        struct fuse_lowlevel_ops llop = fuse_path_ops;
 
        f = (struct fuse *) calloc(1, sizeof(struct fuse));
        if (f == NULL) {
                fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate fuse object\n");
                goto out;
        }
 
        f->conf.entry_timeout = 1.0;
        f->conf.attr_timeout = 1.0;
        f->conf.negative_timeout = 0.0;
        f->conf.intr_signal = FUSE_DEFAULT_INTR_SIGNAL;
 
        /* Parse options */
        if (fuse_opt_parse(args, &f->conf, fuse_lib_opts,
                           fuse_lib_opt_proc) == -1)
                goto out_free;
 
        pthread_mutex_lock(&fuse_context_lock);
        static int builtin_modules_registered = 0;
        /* Have the builtin modules already been registered? */
        if (builtin_modules_registered == 0) {
                /* If not, register them. */
                fuse_register_module("subdir", fuse_module_subdir_factory, NULL);
#ifdef HAVE_ICONV
                fuse_register_module("iconv", fuse_module_iconv_factory, NULL);
#endif
                builtin_modules_registered= 1;
        }
        pthread_mutex_unlock(&fuse_context_lock);
 
        if (fuse_create_context_key() == -1)
                goto out_free;
 
        fs = fuse_fs_new(op, op_size, user_data);
        if (!fs)
                goto out_delete_context_key;
 
        f->fs = fs;
 
        /* Oh f**k, this is ugly! */
        if (!fs->op.lock) {
                llop.getlk = NULL;
                llop.setlk = NULL;
        }
 
        f->pagesize = getpagesize();
        init_list_head(&f->partial_slabs);
        init_list_head(&f->full_slabs);
        init_list_head(&f->lru_table);
 
        if (f->conf.modules) {
                char *module;
                char *next;
 
                for (module = f->conf.modules; module; module = next) {
                        char *p;
                        for (p = module; *p && *p != ':'; p++);
                        next = *p ? p + 1 : NULL;
                        *p = '\0';
                        if (module[0] &&
                            fuse_push_module(f, module, args) == -1)
                                goto out_free_fs;
                }
        }
 
        if (!f->conf.ac_attr_timeout_set)
                f->conf.ac_attr_timeout = f->conf.attr_timeout;
 
#if defined(__FreeBSD__) || defined(__NetBSD__)
        /*
         * In FreeBSD, we always use these settings as inode numbers
         * are needed to make getcwd(3) work.
         */
        f->conf.readdir_ino = 1;
#endif
 
        /* not declared globally, to restrict usage of this function */
        struct fuse_session *fuse_session_new_versioned(
                struct fuse_args *args, const struct fuse_lowlevel_ops *op,
                size_t op_size, struct libfuse_version *version,
                void *userdata);
        f->se = fuse_session_new_versioned(args, &llop, sizeof(llop), version,
                                           f);
        if (f->se == NULL)
                goto out_free_fs;
 
        /* Trace topmost layer by default */
        f->fs->debug = f->conf.debug;
        f->ctr = 0;
        f->generation = 0;
        if (node_table_init(&f->name_table) == -1)
                goto out_free_session;
 
        if (node_table_init(&f->id_table) == -1)
                goto out_free_name_table;
 
        pthread_mutex_init(&f->lock, NULL);
 
        root = alloc_node(f);
        if (root == NULL) {
                fuse_log(FUSE_LOG_ERR, "fuse: memory allocation failed\n");
                goto out_free_id_table;
        }
        if (lru_enabled(f)) {
                struct node_lru *lnode = node_lru(root);
                init_list_head(&lnode->lru);
        }
 
        strcpy(root->inline_name, "/");
        root->name = root->inline_name;
        root->parent = NULL;
        root->nodeid = FUSE_ROOT_ID;
        inc_nlookup(root);
        hash_id(f, root);
 
        return f;
 
out_free_id_table:
        free(f->id_table.array);
out_free_name_table:
        free(f->name_table.array);
out_free_session:
        fuse_session_destroy(f->se);
out_free_fs:
        free(f->fs);
        free(f->conf.modules);
out_delete_context_key:
        fuse_delete_context_key();
out_free:
        free(f);
out:
        return NULL;
}
 
/* Emulates 3.0-style fuse_new(), which processes --help */
FUSE_SYMVER("_fuse_new_30", "_fuse_new@FUSE_3.0")
struct fuse *_fuse_new_30(struct fuse_args *args,
                         const struct fuse_operations *op,
                         size_t op_size,
                         struct libfuse_version *version,
                         void *user_data)
{
        struct fuse_config conf = {0};
 
        const struct fuse_opt opts[] = {
                FUSE_LIB_OPT("-h", show_help, 1),
                FUSE_LIB_OPT("--help", show_help, 1),
                FUSE_OPT_END
        };
 
        if (fuse_opt_parse(args, &conf, opts,
                           fuse_lib_opt_proc) == -1)
                return NULL;
 
        if (conf.show_help) {
                fuse_lib_help(args);
                return NULL;
        } else
                return _fuse_new_31(args, op, op_size, version, user_data);
}
 
/* ABI compat version */
struct fuse *fuse_new_31(struct fuse_args *args, const struct fuse_operations *op,
                         size_t op_size, void *user_data);
FUSE_SYMVER("fuse_new_31", "fuse_new@FUSE_3.1")
struct fuse *fuse_new_31(struct fuse_args *args,
                         const struct fuse_operations *op,
                         size_t op_size, void *user_data)
{
                /* unknown version */
        struct libfuse_version version = { 0 };
 
        return _fuse_new_31(args, op, op_size, &version, user_data);
}
 
/*
 * ABI compat version
 * Emulates 3.0-style fuse_new(), which processes --help
 */
struct fuse *fuse_new_30(struct fuse_args *args, const struct fuse_operations *op,
                         size_t op_size, void *user_data);
FUSE_SYMVER("fuse_new_30", "fuse_new@FUSE_3.0")
struct fuse *fuse_new_30(struct fuse_args *args,
                         const struct fuse_operations *op,
                         size_t op_size, void *user_data)
{
        struct fuse_config conf = {0};
 
        const struct fuse_opt opts[] = {
                FUSE_LIB_OPT("-h", show_help, 1),
                FUSE_LIB_OPT("--help", show_help, 1),
                FUSE_OPT_END
        };
 
        if (fuse_opt_parse(args, &conf, opts,
                           fuse_lib_opt_proc) == -1)
                return NULL;
 
        if (conf.show_help) {
                fuse_lib_help(args);
                return NULL;
        } else
                return fuse_new_31(args, op, op_size, user_data);
}
 
 
void fuse_destroy(struct fuse *f)
{
        size_t i;
 
        if (f->conf.intr && f->intr_installed)
                fuse_restore_intr_signal(f->conf.intr_signal);
 
        if (f->fs) {
                fuse_create_context(f);
 
                for (i = 0; i < f->id_table.size; i++) {
                        struct node *node;
 
                        for (node = f->id_table.array[i]; node != NULL;
                             node = node->id_next) {
                                if (node->is_hidden) {
                                        char *path;
                                        if (try_get_path(f, node->nodeid, NULL, &path, NULL, false) == 0) {
                                                fuse_fs_unlink(f->fs, path);
                                                free(path);
                                        }
                                }
                        }
                }
        }
        for (i = 0; i < f->id_table.size; i++) {
                struct node *node;
                struct node *next;
 
                for (node = f->id_table.array[i]; node != NULL; node = next) {
                        next = node->id_next;
                        free_node(f, node);
                        f->id_table.use--;
                }
        }
        assert(list_empty(&f->partial_slabs));
        assert(list_empty(&f->full_slabs));
 
        while (fuse_modules) {
                fuse_put_module(fuse_modules);
        }
        free(f->id_table.array);
        free(f->name_table.array);
        pthread_mutex_destroy(&f->lock);
        fuse_session_destroy(f->se);
        free(f->fs);
        free(f->conf.modules);
        free(f);
        fuse_delete_context_key();
}
 
int fuse_mount(struct fuse *f, const char *mountpoint) {
        return fuse_session_mount(fuse_get_session(f), mountpoint);
}
 
 
void fuse_unmount(struct fuse *f) {
        fuse_session_unmount(fuse_get_session(f));
}
 
int fuse_version(void)
{
        return FUSE_VERSION;
}
 
const char *fuse_pkgversion(void)
{
        return PACKAGE_VERSION;
}