mergerfs/libfuse/lib/fuse.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>

  This program can be distributed under the terms of the GNU LGPLv2.
  See the file COPYING.LIB
*/


/* For pthread_rwlock_t */
#define _GNU_SOURCE

#include "config.h"
#include "fuse_i.h"
#include "fuse_lowlevel.h"
#include "fuse_opt.h"
#include "fuse_misc.h"
#include "fuse_kernel.h"
#include "fuse_dirents.h"

#include <assert.h>
#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <poll.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <time.h>
#include <unistd.h>

#define FUSE_NODE_SLAB 1

#ifndef MAP_ANONYMOUS
#undef FUSE_NODE_SLAB
#endif

#define FUSE_DEFAULT_INTR_SIGNAL SIGUSR1

#define FUSE_UNKNOWN_INO UINT64_MAX
#define OFFSET_MAX 0x7fffffffffffffffLL

#define NODE_TABLE_MIN_SIZE 8192

struct fuse_config
{
  unsigned int uid;
  unsigned int gid;
  unsigned int  umask;
  int remember;
  int debug;
  int use_ino;
  int set_mode;
  int set_uid;
  int set_gid;
  int intr;
  int intr_signal;
  int help;
  int threads;
};

struct fuse_fs
{
  struct fuse_operations op;
  void *user_data;
  int debug;
};

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 first_locked : 1;
  bool second_locked : 1;
  bool done : 1;
};

struct node_table
{
  struct node **array;
  size_t use;
  size_t size;
  size_t split;
};

#define container_of(ptr, type, member) ({                      \
      const typeof( ((type *)0)->member ) *__mptr = (ptr);      \
      (type *)( (char *)__mptr - offsetof(type,member) );})

#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;
  uint64_t 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;
  uint64_t generation;
  int refctr;
  struct node *parent;
  char *name;
  uint64_t nlookup;
  int open_count;
  struct lock *locks;
  uint64_t hidden_fh;
  char is_hidden;
  int treelock;
  struct stat stat_cache;
  char stat_cache_valid;
  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_dh
{
  pthread_mutex_t lock;
  uint64_t        fh;
  fuse_dirents_t  d;
};

struct fuse_context_i
{
  struct fuse_context ctx;
  fuse_req_t req;
};

static pthread_key_t fuse_context_key;
static pthread_mutex_t fuse_context_lock = PTHREAD_MUTEX_INITIALIZER;
static int fuse_context_ref;

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)
    fprintf(stderr, "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,
         const fuse_ino_t  nodeid)
{
  struct node *node = get_node_nocheck(f, nodeid);

  if(!node)
    {
      fprintf(stderr, "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);

  if(node_->is_hidden)
    fuse_fs_free_hide(f_->fs,node_->hidden_fh);

  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;
      }
    fprintf(stderr,
            "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)
    fprintf(stderr, "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
uint64_t
rand64(void)
{
  uint64_t rv;

  rv   = rand();
  rv <<= 32;
  rv  |= rand();

  return rv;
}

static
fuse_ino_t
next_id(struct fuse *f)
{
  do
    {
      f->ctr = ((f->ctr + 1) & UINT64_MAX);
      if(f->ctr == 0)
        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 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;
  strncpy(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);
    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 = -ENOENT;
    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 void queue_element_unlock(struct fuse *f, struct lock_queue_element *qe)
{
  struct node *wnode;

  if (qe->first_locked) {
    wnode = qe->wnode1 ? *qe->wnode1 : NULL;
    unlock_path(f, qe->nodeid1, wnode, NULL);
    qe->first_locked = false;
  }
  if (qe->second_locked) {
    wnode = qe->wnode2 ? *qe->wnode2 : NULL;
    unlock_path(f, qe->nodeid2, wnode, NULL);
    qe->second_locked = false;
  }
}

static void queue_element_wakeup(struct fuse *f, struct lock_queue_element *qe)
{
  int err;
  bool first = (qe == f->lockq);

  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->first_locked) {
    err = try_get_path(f, qe->nodeid1, qe->name1, qe->path1,
                       qe->wnode1, true);
    if (!err)
      qe->first_locked = true;
    else if (err != -EAGAIN)
      goto err_unlock;
  }
  if (!qe->second_locked && qe->path2) {
    err = try_get_path(f, qe->nodeid2, qe->name2, qe->path2,
                       qe->wnode2, true);
    if (!err)
      qe->second_locked = true;
    else if (err != -EAGAIN)
      goto err_unlock;
  }

  if (qe->first_locked && (qe->second_locked || !qe->path2)) {
    err = 0;
    goto done;
  }

  /*
   * Only let the first element be partially locked otherwise there could
   * be a deadlock.
   *
   * But do allow the first element to be partially locked to prevent
   * starvation.
   */
  if (!first)
    queue_element_unlock(f, qe);

  /* keep trying */
  return;

 err_unlock:
  queue_element_unlock(f, qe);
 done:
  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)
      fprintf(stderr, "%s %li (w)\n",	msg, wnode->nodeid);
    else
      fprintf(stderr, "%s %li\n", msg, nodeid);
  }
}

static void queue_path(struct fuse *f, struct lock_queue_element *qe)
{
  struct lock_queue_element **qp;

  qe->done = false;
  qe->first_locked = false;
  qe->second_locked = 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_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);
}

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 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);
  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);
  }
  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,
            const fuse_ino_t  nodeid,
            const 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)
{
  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)
    unlink_node(f, newnode);


  unhash_name(f, node);
  if (hash_name(f, node, newdir, newname) == -1) {
    err = -ENOMEM;
    goto out;
  }

 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)
    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;
}

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);
}

int
fuse_fs_getattr(struct fuse_fs  *fs,
                const char      *path,
                struct stat     *buf,
                fuse_timeouts_t *timeout)
{
  if(fs->op.getattr == NULL)
    return -ENOSYS;

  if(fs->debug)
    fprintf(stderr,"getattr %s\n",path);

  fuse_get_context()->private_data = fs->user_data;

  return fs->op.getattr(path,buf,timeout);
}

int
fuse_fs_fgetattr(struct fuse_fs        *fs,
                 struct stat           *buf,
                 struct fuse_file_info *fi,
                 fuse_timeouts_t       *timeout)
{
  if(fs->op.fgetattr == NULL)
    return -ENOSYS;

  fuse_get_context()->private_data = fs->user_data;
  if(fs->debug)
    fprintf(stderr,"fgetattr[%llu]\n",(unsigned long long)fi->fh);

  return fs->op.fgetattr(buf,fi,timeout);
}

int
fuse_fs_rename(struct fuse_fs *fs,
               const char     *oldpath,
               const char     *newpath)
{
  fuse_get_context()->private_data = fs->user_data;

  if(fs->op.rename)
    return fs->op.rename(oldpath, newpath);

  return -ENOSYS;
}

int
fuse_fs_prepare_hide(struct fuse_fs *fs_,
                     const char     *path_,
                     uint64_t       *fh_)
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.prepare_hide)
    return fs_->op.prepare_hide(path_,fh_);

  return -ENOSYS;
}

int
fuse_fs_free_hide(struct fuse_fs *fs_,
                  uint64_t        fh_)
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.free_hide)
    return fs_->op.free_hide(fh_);

  return -ENOSYS;
}

int fuse_fs_unlink(struct fuse_fs *fs, const char *path)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.unlink) {
    if (fs->debug)
      fprintf(stderr, "unlink %s\n", path);

    return fs->op.unlink(path);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_rmdir(struct fuse_fs *fs, const char *path)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.rmdir) {
    if (fs->debug)
      fprintf(stderr, "rmdir %s\n", path);

    return fs->op.rmdir(path);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "symlink %s %s\n", linkname, path);

    return fs->op.symlink(linkname, path);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "link %s %s\n", oldpath, newpath);

    return fs->op.link(oldpath, newpath);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_release(struct fuse_fs *fs,
		    struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.release) {
    if (fs->debug)
      fprintf(stderr, "release%s[%llu] flags: 0x%x\n",
              fi->flush ? "+flush" : "",
              (unsigned long long) fi->fh, fi->flags);

    return fs->op.release(fi);
  } else {
    return 0;
  }
}

int fuse_fs_opendir(struct fuse_fs *fs, const char *path,
		    struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.opendir) {
    int err;

    if (fs->debug)
      fprintf(stderr, "opendir flags: 0x%x %s\n", fi->flags,
              path);

    err = fs->op.opendir(path,fi);

    if (fs->debug && !err)
      fprintf(stderr, "   opendir[%lli] flags: 0x%x %s\n",
              (unsigned long long) fi->fh, fi->flags, path);

    return err;
  } else {
    return 0;
  }
}

int fuse_fs_open(struct fuse_fs *fs, const char *path,
		 struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.open) {
    int err;

    if (fs->debug)
      fprintf(stderr, "open flags: 0x%x %s\n", fi->flags,
              path);

    err = fs->op.open(path,fi);

    if (fs->debug && !err)
      fprintf(stderr, "   open[%lli] flags: 0x%x %s\n",
              (unsigned long long) fi->fh, fi->flags, path);

    return err;
  } else {
    return 0;
  }
}

static void fuse_free_buf(struct fuse_bufvec *buf)
{
  if (buf != NULL) {
    size_t i;

    for (i = 0; i < buf->count; i++)
      free(buf->buf[i].mem);
    free(buf);
  }
}

int fuse_fs_read_buf(struct fuse_fs *fs,
		     struct fuse_bufvec **bufp, size_t size, off_t off,
		     struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.read || fs->op.read_buf) {
    int res;

    if (fs->debug)
      fprintf(stderr,
              "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(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(mem, size, off, fi);
      if (res >= 0)
        buf->buf[0].size = res;
    }

    if (fs->debug && res >= 0)
      fprintf(stderr, "   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) > (int) size)
      fprintf(stderr, "fuse: read too many bytes\n");

    if (res < 0)
      return res;

    return 0;
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_read(struct fuse_fs *fs, char *mem, size_t size,
		 off_t off, struct fuse_file_info *fi)
{
  int res;
  struct fuse_bufvec *buf = NULL;

  res = fuse_fs_read_buf(fs, &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);

  return res;
}

int fuse_fs_write_buf(struct fuse_fs *fs,
		      struct fuse_bufvec *buf, off_t off,
		      struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.write_buf || fs->op.write) {
    int res;
    size_t size = fuse_buf_size(buf);

    assert(buf->idx == 0 && buf->off == 0);
    if (fs->debug)
      fprintf(stderr,
              "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(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(flatbuf->mem, flatbuf->size,
                         off, fi);
    out_free:
      free(mem);
    }
  out:
    if (fs->debug && res >= 0)
      fprintf(stderr, "   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)
      fprintf(stderr, "fuse: wrote too many bytes\n");

    return res;
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_write(struct fuse_fs *fs, 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, &bufv, off, fi);
}

int fuse_fs_fsync(struct fuse_fs *fs, int datasync,
		  struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.fsync) {
    if (fs->debug)
      fprintf(stderr, "fsync[%llu] datasync: %i\n",
              (unsigned long long) fi->fh, datasync);

    return fs->op.fsync(datasync, fi);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_fsyncdir(struct fuse_fs *fs, int datasync,
		     struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.fsyncdir) {
    if (fs->debug)
      fprintf(stderr, "fsyncdir[%llu] datasync: %i\n",
              (unsigned long long) fi->fh, datasync);

    return fs->op.fsyncdir(datasync, fi);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_flush(struct fuse_fs *fs,
		  struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.flush) {
    if (fs->debug)
      fprintf(stderr, "flush[%llu]\n",
              (unsigned long long) fi->fh);

    return fs->op.flush(fi);
  } else {
    return -ENOSYS;
  }
}

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)
      fprintf(stderr, "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,
		       struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.releasedir) {
    if (fs->debug)
      fprintf(stderr, "releasedir[%llu] flags: 0x%x\n",
              (unsigned long long) fi->fh, fi->flags);

    return fs->op.releasedir(fi);
  } else {
    return 0;
  }
}

int
fuse_fs_readdir(struct fuse_fs        *fs,
                struct fuse_file_info *fi,
                fuse_dirents_t        *buf)
{
  if(fs->op.readdir == NULL)
    return -ENOSYS;

  fuse_get_context()->private_data = fs->user_data;

  return fs->op.readdir(fi,buf);
}

int
fuse_fs_readdir_plus(struct fuse_fs        *fs_,
                     struct fuse_file_info *ffi_,
                     fuse_dirents_t        *buf_)
{
  if(fs_->op.readdir_plus == NULL)
    return -ENOSYS;

  fuse_get_context()->private_data = fs_->user_data;

  return fs_->op.readdir_plus(ffi_,buf_);
}

int fuse_fs_create(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.create) {
    int err;

    if (fs->debug)
      fprintf(stderr,
              "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)
      fprintf(stderr, "   create[%llu] flags: 0x%x %s\n",
              (unsigned long long) fi->fh, fi->flags, path);

    return err;
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_lock(struct fuse_fs *fs,
		 struct fuse_file_info *fi, int cmd, struct flock *lock)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.lock) {
    if (fs->debug)
      fprintf(stderr, "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(fi, cmd, lock);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_flock(struct fuse_fs *fs,
		  struct fuse_file_info *fi, int op)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.flock) {
    if (fs->debug) {
      int xop = op & ~LOCK_NB;

      fprintf(stderr, "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(fi, op);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.chown) {
    if (fs->debug)
      fprintf(stderr, "chown %s %lu %lu\n", path,
              (unsigned long) uid, (unsigned long) gid);

    return fs->op.chown(path, uid, gid);
  } else {
    return -ENOSYS;
  }
}

int
fuse_fs_fchown(struct fuse_fs              *fs_,
               const struct fuse_file_info *ffi_,
               const uid_t                  uid_,
               const gid_t                  gid_)
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.fchown)
    return fs_->op.fchown(ffi_,uid_,gid_);

  return -ENOSYS;
}

int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.truncate) {
    if (fs->debug)
      fprintf(stderr, "truncate %s %llu\n", path,
              (unsigned long long) size);

    return fs->op.truncate(path, size);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_ftruncate(struct fuse_fs *fs, off_t size,
		      struct fuse_file_info *fi)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->debug)
    fprintf(stderr, "ftruncate[%llu] %llu\n",
            (unsigned long long) fi->fh,
            (unsigned long long) size);

  return fs->op.ftruncate(size, fi);
}

int fuse_fs_utimens(struct fuse_fs *fs, const char *path,
		    const struct timespec tv[2])
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.utimens) {
    if (fs->debug)
      fprintf(stderr, "utimens %s %li.%09lu %li.%09lu\n",
              path, tv[0].tv_sec, tv[0].tv_nsec,
              tv[1].tv_sec, tv[1].tv_nsec);

    return fs->op.utimens(path, tv);
  } else if(fs->op.utime) {
    struct utimbuf buf;

    if (fs->debug)
      fprintf(stderr, "utime %s %li %li\n", path,
              tv[0].tv_sec, tv[1].tv_sec);

    buf.actime = tv[0].tv_sec;
    buf.modtime = tv[1].tv_sec;
    return fs->op.utime(path, &buf);
  } else {
    return -ENOSYS;
  }
}

int
fuse_fs_futimens(struct fuse_fs *fs_,
                 const struct fuse_file_info *ffi_,
                 const struct timespec tv_[2])
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.futimens)
    return fs_->op.futimens(ffi_,tv_);

  return -ENOSYS;
}

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) {
    if (fs->debug)
      fprintf(stderr, "access %s 0%o\n", path, mask);

    return fs->op.access(path, mask);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "readlink %s %lu\n", path,
              (unsigned long) len);

    return fs->op.readlink(path, buf, len);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "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);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "mkdir %s 0%o umask=0%03o\n",
              path, mode, fuse_get_context()->umask);

    return fs->op.mkdir(path, mode);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "setxattr %s %s %lu 0x%x\n",
              path, name, (unsigned long) size, flags);

    return fs->op.setxattr(path, name, value, size, flags);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "getxattr %s %s %lu\n",
              path, name, (unsigned long) size);

    return fs->op.getxattr(path, name, value, size);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "listxattr %s %lu\n",
              path, (unsigned long) size);

    return fs->op.listxattr(path, list, size);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "bmap %s blocksize: %lu index: %llu\n",
              path, (unsigned long) blocksize,
              (unsigned long long) *idx);

    return fs->op.bmap(path, blocksize, idx);
  } else {
    return -ENOSYS;
  }
}

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) {
    if (fs->debug)
      fprintf(stderr, "removexattr %s %s\n", path, name);

    return fs->op.removexattr(path, name);
  } else {
    return -ENOSYS;
  }
}

int fuse_fs_ioctl(struct fuse_fs *fs, unsigned long cmd, void *arg,
		  struct fuse_file_info *fi, unsigned int flags,
                  void *data, uint32_t *out_size)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.ioctl) {
    if (fs->debug)
      fprintf(stderr, "ioctl[%llu] 0x%lx flags: 0x%x\n",
              (unsigned long long) fi->fh, cmd, flags);

    return fs->op.ioctl(cmd, arg, fi, flags, data, out_size);
  } else
    return -ENOSYS;
}

int fuse_fs_poll(struct fuse_fs *fs,
		 struct fuse_file_info *fi, struct fuse_pollhandle *ph,
		 unsigned *reventsp)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.poll) {
    int res;

    if (fs->debug)
      fprintf(stderr, "poll[%llu] ph: %p\n",
              (unsigned long long) fi->fh, ph);

    res = fs->op.poll(fi, ph, reventsp);

    if (fs->debug && !res)
      fprintf(stderr, "   poll[%llu] revents: 0x%x\n",
              (unsigned long long) fi->fh, *reventsp);

    return res;
  } else
    return -ENOSYS;
}

int fuse_fs_fallocate(struct fuse_fs *fs, 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) {
    if (fs->debug)
      fprintf(stderr, "fallocate mode %x, offset: %llu, length: %llu\n",
              mode,
              (unsigned long long) offset,
              (unsigned long long) length);

    return fs->op.fallocate(mode, offset, length, fi);
  } else
    return -ENOSYS;
}

ssize_t
fuse_fs_copy_file_range(struct fuse_fs        *fs_,
                        struct fuse_file_info *ffi_in_,
                        off_t                  off_in_,
                        struct fuse_file_info *ffi_out_,
                        off_t                  off_out_,
                        size_t                 len_,
                        int                    flags_)
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.copy_file_range == NULL)
    return -ENOSYS;

  return fs_->op.copy_file_range(ffi_in_,
                                 off_in_,
                                 ffi_out_,
                                 off_out_,
                                 len_,
                                 flags_);
}

int
node_open(const struct node *node_)
{
  return ((node_ != NULL) &&
          (node_->open_count > 0));
}

#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 *stnew_)
{
  struct stat *stold;

  stold = &node_->stat_cache;
  if((node_->stat_cache_valid) &&
     ((stold->st_mtim.tv_sec  != stnew_->st_mtim.tv_sec)  ||
      (stold->st_mtim.tv_nsec != stnew_->st_mtim.tv_nsec) ||
      (stold->st_size         != stnew_->st_size)))
    node_->stat_cache_valid = 0;

  *stold = *stnew_;
}

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));

  if(fi)
    res = fuse_fs_fgetattr(f->fs,&e->attr,fi,&e->timeout);
  else
    res = fuse_fs_getattr(f->fs,path,&e->attr,&e->timeout);

  if(res == 0)
    {
      struct node *node;

      node = find_node(f,nodeid,name);
      if(node == NULL)
        {
          res = -ENOMEM;
        }
      else
        {
          e->ino        = node->nodeid;
          e->generation = node->generation;

          pthread_mutex_lock(&f->lock);
          update_stat(node,&e->attr);
          pthread_mutex_unlock(&f->lock);

          set_stat(f,e->ino,&e->attr);
          if(f->conf.debug)
            fprintf(stderr,
                    "   NODEID: %llu\n"
                    "   GEN: %llu\n",
                    (unsigned long long)e->ino,
                    (unsigned long long)e->generation);
        }
    }

  return res;
}

static struct fuse_context_i *fuse_get_context_internal(void)
{
  struct fuse_context_i *c;

  c = (struct fuse_context_i *) pthread_getspecific(fuse_context_key);
  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 */
      fprintf(stderr, "fuse: failed to allocate thread specific data\n");
      abort();
    }
    pthread_setspecific(fuse_context_key, c);
  }
  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) {
      fprintf(stderr, "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_get_context_internal();
  const struct fuse_ctx *ctx = fuse_req_ctx(req);
  c->req = req;
  c->ctx.fuse = req_fuse(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)
{
  fuse_get_context()->private_data = fs->user_data;
  if (!fs->op.write_buf)
    conn->want &= ~FUSE_CAP_SPLICE_READ;
  if (!fs->op.lock)
    conn->want &= ~FUSE_CAP_POSIX_LOCKS;
  if (!fs->op.flock)
    conn->want &= ~FUSE_CAP_FLOCK_LOCKS;
  if (fs->op.init)
    fs->user_data = fs->op.init(conn);
}

static void fuse_lib_init(void *data, struct fuse_conn_info *conn)
{
  struct fuse *f = (struct fuse *) data;
  struct fuse_context_i *c = fuse_get_context_internal();

  memset(c, 0, sizeof(*c));
  c->ctx.fuse = f;
  conn->want |= FUSE_CAP_EXPORT_SUPPORT;
  fuse_fs_init(f->fs, conn);
}

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);
  free(fs);
}

static void fuse_lib_destroy(void *data)
{
  struct fuse *f = (struct fuse *) data;
  struct fuse_context_i *c = fuse_get_context_internal();

  memset(c, 0, sizeof(*c));
  c->ctx.fuse = f;
  fuse_fs_destroy(f->fs);
  f->fs = NULL;
}

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;
  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)
          fprintf(stderr, "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)
          fprintf(stderr, "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)
      fprintf(stderr, "LOOKUP %s\n", path);
    fuse_prepare_interrupt(f, req, &d);
    err = lookup_path(f, parent, name, path, &e, NULL);
    if (err == -ENOENT) {
      e.ino = 0;
      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,
          const fuse_ino_t ino,
          const uint64_t nlookup)
{
  if(f->conf.debug)
    fprintf(stderr,
            "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,
                const fuse_ino_t ino,
                const 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)
{

  int err;
  char *path;
  struct fuse *f;
  struct stat buf;
  struct node *node;
  fuse_timeouts_t timeout;
  struct fuse_file_info ffi = {0};

  f = req_fuse_prepare(req);
  if(fi == NULL)
    {
      pthread_mutex_lock(&f->lock);
      node = get_node(f,ino);
      if(node->is_hidden)
        {
          fi = &ffi;
          fi->fh = node->hidden_fh;
        }
      pthread_mutex_unlock(&f->lock);
    }

  memset(&buf, 0, sizeof(buf));

  err = 0;
  path = NULL;
  if((fi == NULL) || (f->fs->op.fgetattr == NULL))
    err = get_path(f,ino,&path);

  if(!err)
    {
      struct fuse_intr_data d;

      fuse_prepare_interrupt(f,req,&d);

      err = ((fi == NULL) ?
             fuse_fs_getattr(f->fs,path,&buf,&timeout) :
             fuse_fs_fgetattr(f->fs,&buf,fi,&timeout));

      fuse_finish_interrupt(f,req,&d);

      free_path(f,ino,path);
    }

  if(!err)
    {
      pthread_mutex_lock(&f->lock);
      node = get_node(f,ino);
      update_stat(node,&buf);
      pthread_mutex_unlock(&f->lock);
      set_stat(f,ino,&buf);
      fuse_reply_attr(req,&buf,timeout.attr);
    }
  else
    {
      reply_err(req, err);
    }
}

int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode)
{
  fuse_get_context()->private_data = fs->user_data;
  if (fs->op.chmod)
    return fs->op.chmod(path, mode);
  else
    return -ENOSYS;
}

int
fuse_fs_fchmod(struct fuse_fs              *fs_,
               const struct fuse_file_info *ffi_,
               const mode_t                 mode_)
{
  fuse_get_context()->private_data = fs_->user_data;

  if(fs_->op.fchmod)
    return fs_->op.fchmod(ffi_,mode_);

  return -ENOSYS;
}

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;
  struct node *node;
  fuse_timeouts_t timeout;
  struct fuse_file_info ffi = {0};

  if(fi == NULL)
    {
      pthread_mutex_lock(&f->lock);
      node = get_node(f,ino);
      if(node->is_hidden)
        {
          fi = &ffi;
          fi->fh = node->hidden_fh;
        }
      pthread_mutex_unlock(&f->lock);
    }

  memset(&buf,0,sizeof(buf));

  err = 0;
  path = NULL;
  if(fi == NULL)
    err = get_path(f,ino,&path);

  if(!err)
    {
      struct fuse_intr_data d;

      fuse_prepare_interrupt(f,req,&d);

      err = 0;
      if (!err && (valid & FATTR_MODE))
        err = ((fi == NULL) ?
               fuse_fs_chmod(f->fs,path,attr->st_mode) :
               fuse_fs_fchmod(f->fs,fi,attr->st_mode));

      if(!err && (valid & (FATTR_UID | FATTR_GID)))
        {
          uid_t uid = ((valid & FATTR_UID) ? attr->st_uid : (uid_t) -1);
          gid_t gid = ((valid & FATTR_GID) ? attr->st_gid : (gid_t) -1);

          err = ((fi == NULL) ?
                 fuse_fs_chown(f->fs,path,uid,gid) :
                 fuse_fs_fchown(f->fs,fi,uid,gid));
        }

      if(!err && (valid & FATTR_SIZE))
        err = ((fi == NULL) ?
               fuse_fs_truncate(f->fs,path,attr->st_size) :
               fuse_fs_ftruncate(f->fs,attr->st_size,fi));

#ifdef HAVE_UTIMENSAT
      if(!err && (valid & (FATTR_ATIME | FATTR_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 & FATTR_ATIME_NOW)
            tv[0].tv_nsec = UTIME_NOW;
          else if(valid & FATTR_ATIME)
            tv[0] = attr->st_atim;

          if(valid & FATTR_MTIME_NOW)
            tv[1].tv_nsec = UTIME_NOW;
          else if(valid & FATTR_MTIME)
            tv[1] = attr->st_mtim;

          err = ((fi == NULL) ?
                 fuse_fs_utimens(f->fs,path,tv) :
                 fuse_fs_futimens(f->fs,fi,tv));
        }
      else
#endif
        if(!err && ((valid & (FATTR_ATIME|FATTR_MTIME)) == (FATTR_ATIME|FATTR_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 = ((fi == NULL) ?
                   fuse_fs_utimens(f->fs,path,tv) :
                   fuse_fs_futimens(f->fs,fi,tv));
          }

      if (!err)
        err = ((fi == NULL) ?
               fuse_fs_getattr(f->fs,path,&buf,&timeout) :
               fuse_fs_fgetattr(f->fs,&buf,fi,&timeout));

      fuse_finish_interrupt(f,req,&d);
      free_path(f,ino,path);
    }


  if(!err)
    {
      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,timeout.attr);
    }
  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, &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)
{
  int err;
  char *path;
  struct fuse *f;
  struct node *wnode;
  struct fuse_intr_data d;

  f = req_fuse_prepare(req);
  err = get_path_wrlock(f,parent,name,&path,&wnode);

  if(!err)
    {
      fuse_prepare_interrupt(f,req,&d);

      pthread_mutex_lock(&f->lock);
      if(node_open(wnode))
        {
          err = fuse_fs_prepare_hide(f->fs,path,&wnode->hidden_fh);
          if(!err)
            wnode->is_hidden = 1;
        }
      pthread_mutex_unlock(&f->lock);

      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)
{
  int err;
  struct fuse *f;
  char *oldpath;
  char *newpath;
  struct node *wnode1;
  struct node *wnode2;
  struct fuse_intr_data d;

  f = req_fuse_prepare(req);
  err = get_path2(f,olddir,oldname,newdir,newname,
                  &oldpath,&newpath,&wnode1,&wnode2);

  if(!err)
    {
      fuse_prepare_interrupt(f,req,&d);

      pthread_mutex_lock(&f->lock);
      if(node_open(wnode2))
        {
          err = fuse_fs_prepare_hide(f->fs,newpath,&wnode2->hidden_fh);
          if(!err)
            wnode2->is_hidden = 1;
        }
      pthread_mutex_unlock(&f->lock);

      err = fuse_fs_rename(f->fs,oldpath,newpath);
      if(!err)
        err = rename_node(f,olddir,oldname,newdir,newname);

      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,
			    struct fuse_file_info *fi)
{
  struct node *node;
  uint64_t fh;
  int was_hidden;

  fh = 0;
  fuse_fs_release(f->fs, fi);

  pthread_mutex_lock(&f->lock);
  node = get_node(f, ino);
  assert(node->open_count > 0);
  node->open_count--;
  was_hidden = 0;
  if (node->is_hidden && (node->open_count == 0)) {
    was_hidden = 1;
    node->is_hidden = 0;
    fh = node->hidden_fh;
  }
  pthread_mutex_unlock(&f->lock);

  if(was_hidden)
    fuse_fs_free_hide(f->fs,fh);
}

static
void
fuse_lib_create(fuse_req_t             req,
                fuse_ino_t             parent,
                const char            *name,
                mode_t                 mode,
                struct fuse_file_info *fi)
{
  int err;
  char *path;
  struct fuse *f;
  struct fuse_intr_data d;
  struct fuse_entry_param e;

  f = req_fuse_prepare(req);
  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, fi);
            }
          else if(!S_ISREG(e.attr.st_mode))
            {
              err = -EIO;
              fuse_fs_release(f->fs, fi);
              forget_node(f, e.ino, 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, 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;
  fuse_timeouts_t timeout;

  pthread_mutex_lock(&f->lock);

  node = get_node(f,ino);
  if(node->stat_cache_valid)
    {
      int err;
      struct stat stbuf;

      pthread_mutex_unlock(&f->lock);
      err = fuse_fs_fgetattr(f->fs,&stbuf,fi,&timeout);
      pthread_mutex_lock(&f->lock);

      if(!err)
        update_stat(node,&stbuf);
      else
        node->stat_cache_valid = 0;
    }

  if(node->stat_cache_valid)
    fi->keep_cache = 1;

  node->stat_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)
{
  int err;
  char *path;
  struct fuse *f;
  struct fuse_intr_data d;

  f = req_fuse_prepare(req);
  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 (fi && fi->auto_cache)
            open_auto_cache(f, ino, path, fi);
        }
      fuse_finish_interrupt(f, req, &d);
    }

  if(!err)
    {
      pthread_mutex_lock(&f->lock);
      get_node(f,ino)->open_count++;
      pthread_mutex_unlock(&f->lock);
      /* The open syscall was interrupted, so it must be cancelled */
      if(fuse_reply_open(req, fi) == -ENOENT)
        fuse_do_release(f, ino, 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;
  int res;
  struct fuse_intr_data d;

  fuse_prepare_interrupt(f, req, &d);
  res = fuse_fs_read_buf(f->fs, &buf, size, off, fi);
  fuse_finish_interrupt(f, req, &d);

  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);
  int res;
  struct fuse_intr_data d;

  fuse_prepare_interrupt(f, req, &d);
  res = fuse_fs_write_buf(f->fs, buf, off, fi);
  fuse_finish_interrupt(f, req, &d);
  free_path(f, ino, NULL);

  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);
  int err;
  struct fuse_intr_data d;

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_fsync(f->fs, datasync, fi);
  fuse_finish_interrupt(f, req, &d);

  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 *) calloc(1,sizeof(struct fuse_dh));
  if (dh == NULL) {
    reply_err(req, -ENOMEM);
    return;
  }

  fuse_dirents_init(&dh->d);
  fuse_mutex_init(&dh->lock);

  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->keep_cache    = fi.keep_cache;
    llfi->cache_readdir = fi.cache_readdir;
  }

  if (!err) {
    if (fuse_reply_open(req, llfi) == -ENOENT) {
      /* The opendir syscall was interrupted, so it
         must be cancelled */
      fuse_fs_releasedir(f->fs, &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
readdir_fill(struct fuse           *f_,
             fuse_req_t             req_,
             fuse_dirents_t        *d_,
             struct fuse_file_info *fi_)
{
  int rv;
  struct fuse_intr_data intr_data;

  fuse_prepare_interrupt(f_,req_,&intr_data);
  rv = fuse_fs_readdir(f_->fs,fi_,d_);
  fuse_finish_interrupt(f_,req_,&intr_data);

  return rv;
}

static
int
readdir_plus_fill(struct fuse           *f_,
                  fuse_req_t             req_,
                  fuse_dirents_t        *d_,
                  struct fuse_file_info *fi_)
{
  int rv;
  struct fuse_intr_data intr_data;

  fuse_prepare_interrupt(f_,req_,&intr_data);
  rv = fuse_fs_readdir_plus(f_->fs,fi_,d_);
  fuse_finish_interrupt(f_,req_,&intr_data);

  return rv;
}

static
size_t
readdir_buf_size(fuse_dirents_t *d_,
                 size_t          size_,
                 off_t           off_)
{
  if(off_ >= kv_size(d_->offs))
    return 0;
  if((kv_A(d_->offs,off_) + size_) > d_->data_len)
    return (d_->data_len - kv_A(d_->offs,off_));
  return size_;
}

static
char*
readdir_buf(fuse_dirents_t *d_,
            off_t           off_)
{
  return &d_->buf[kv_A(d_->offs,off_)];
}

static
void
fuse_lib_readdir(fuse_req_t             req_,
                 fuse_ino_t             ino_,
                 size_t                 size_,
                 off_t                  off_,
                 struct fuse_file_info *llffi_)
{
  int rv;
  struct fuse *f;
  fuse_dirents_t *d;
  struct fuse_dh *dh;
  struct fuse_file_info fi;

  f  = req_fuse_prepare(req_);
  dh = get_dirhandle(llffi_,&fi);
  d  = &dh->d;

  pthread_mutex_lock(&dh->lock);

  rv = 0;
  if((off_ == 0) || (d->data_len == 0))
    rv = readdir_fill(f,req_,d,&fi);

  if(rv)
    {
      reply_err(req_,rv);
      goto out;
    }

  size_ = readdir_buf_size(d,size_,off_);

  fuse_reply_buf(req_,
                 readdir_buf(d,off_),
                 size_);

 out:
  pthread_mutex_unlock(&dh->lock);
}

static
void
fuse_lib_readdir_plus(fuse_req_t             req_,
                      fuse_ino_t             ino_,
                      size_t                 size_,
                      off_t                  off_,
                      struct fuse_file_info *llffi_)
{
  int rv;
  struct fuse *f;
  fuse_dirents_t *d;
  struct fuse_dh *dh;
  struct fuse_file_info fi;

  f  = req_fuse_prepare(req_);
  dh = get_dirhandle(llffi_,&fi);
  d  = &dh->d;

  pthread_mutex_lock(&dh->lock);

  rv = 0;
  if((off_ == 0) || (d->data_len == 0))
    rv = readdir_plus_fill(f,req_,d,&fi);

  if(rv)
    {
      reply_err(req_,rv);
      goto out;
    }

  size_ = readdir_buf_size(d,size_,off_);

  fuse_reply_buf(req_,
                 readdir_buf(d,off_),
                 size_);

 out:
  pthread_mutex_unlock(&dh->lock);
}

static
void
fuse_lib_releasedir(fuse_req_t             req_,
                    fuse_ino_t             ino_,
                    struct fuse_file_info *llfi_)
{
  struct fuse *f;
  struct fuse_dh *dh;
  struct fuse_intr_data d;
  struct fuse_file_info fi;

  f  = req_fuse_prepare(req_);
  dh = get_dirhandle(llfi_,&fi);

  fuse_prepare_interrupt(f,req_,&d);
  fuse_fs_releasedir(f->fs,&fi);
  fuse_finish_interrupt(f,req_,&d);

  /* Done to keep race condition between last readdir reply and the unlock */
  pthread_mutex_lock(&dh->lock);
  pthread_mutex_unlock(&dh->lock);
  pthread_mutex_destroy(&dh->lock);
  fuse_dirents_free(&dh->d);
  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;
  int err;
  struct fuse_intr_data d;

  get_dirhandle(llfi, &fi);

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_fsyncdir(f->fs, datasync, &fi);
  fuse_finish_interrupt(f, req, &d);

  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
void
fuse_lib_copy_file_range(fuse_req_t             req_,
                         fuse_ino_t             nodeid_in_,
                         off_t                  off_in_,
                         struct fuse_file_info *ffi_in_,
                         fuse_ino_t             nodeid_out_,
                         off_t                  off_out_,
                         struct fuse_file_info *ffi_out_,
                         size_t                 len_,
                         int                    flags_)
{
  ssize_t rv;
  struct fuse *f;
  struct fuse_intr_data d;

  f = req_fuse_prepare(req_);

  fuse_prepare_interrupt(f,req_,&d);

  rv = fuse_fs_copy_file_range(f->fs,
                               ffi_in_,
                               off_in_,
                               ffi_out_,
                               off_out_,
                               len_,
                               flags_);

  fuse_finish_interrupt(f,req_,&d);

  if(rv >= 0)
    fuse_reply_write(req_,rv);
  else
    reply_err(req_,rv);
}

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,
			     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, fi);
  errlock = fuse_fs_lock(f->fs, 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;
  int err = 0;

  if (fi->flush) {
    err = fuse_flush_common(f, req, ino, fi);
    if (err == -ENOSYS)
      err = 0;
  }

  fuse_prepare_interrupt(f, req, &d);
  fuse_do_release(f, ino, fi);
  fuse_finish_interrupt(f, req, &d);

  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);
  int err;

  err = fuse_flush_common(f, req, ino, fi);

  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);
  int err;
  struct fuse_intr_data d;

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_lock(f->fs, fi, cmd, lock);
  fuse_finish_interrupt(f, req, &d);

  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);
  int err;
  struct fuse_intr_data d;

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_flock(f->fs, fi, op);
  fuse_finish_interrupt(f, req, &d);

  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 long cmd, void *arg,
			   struct fuse_file_info *llfi, unsigned int flags,
			   const void *in_buf, uint32_t in_bufsz,
			   uint32_t out_bufsz_)
{
  struct fuse *f = req_fuse_prepare(req);
  struct fuse_intr_data d;
  struct fuse_file_info fi;
  char *out_buf = NULL;
  int err;
  uint32_t out_bufsz = out_bufsz_;

  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)
    memcpy(out_buf, in_buf, in_bufsz);

  fuse_prepare_interrupt(f, req, &d);

  err = fuse_fs_ioctl(f->fs, cmd, arg, &fi, flags,
                      out_buf ?: (void *)in_buf, &out_bufsz);

  fuse_finish_interrupt(f, req, &d);

  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;
  int err;
  unsigned revents = 0;

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_poll(f->fs, fi, ph, &revents);
  fuse_finish_interrupt(f, req, &d);

  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;
  int err;

  fuse_prepare_interrupt(f, req, &d);
  err = fuse_fs_fallocate(f->fs, mode, offset, length, fi);
  fuse_finish_interrupt(f, req, &d);

  reply_err(req, err);
}

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,
  .readdir_plus    = fuse_lib_readdir_plus,
  .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,
};

int fuse_notify_poll(struct fuse_pollhandle *ph)
{
  return fuse_lowlevel_notify_poll(ph);
}

static void free_cmd(struct fuse_cmd *cmd)
{
  free(cmd->buf);
  free(cmd);
}

void fuse_process_cmd(struct fuse *f, struct fuse_cmd *cmd)
{
  fuse_session_process(f->se, cmd->buf, cmd->buflen, cmd->ch);
  free_cmd(cmd);
}

int fuse_exited(struct fuse *f)
{
  return fuse_session_exited(f->se);
}

struct fuse_session *fuse_get_session(struct fuse *f)
{
  return f->se;
}

static struct fuse_cmd *fuse_alloc_cmd(size_t bufsize)
{
  struct fuse_cmd *cmd = (struct fuse_cmd *) malloc(sizeof(*cmd));
  if (cmd == NULL) {
    fprintf(stderr, "fuse: failed to allocate cmd\n");
    return NULL;
  }
  cmd->buf = (char *) malloc(bufsize);
  if (cmd->buf == NULL) {
    fprintf(stderr, "fuse: failed to allocate read buffer\n");
    free(cmd);
    return NULL;
  }
  return cmd;
}

struct fuse_cmd *fuse_read_cmd(struct fuse *f)
{
  struct fuse_chan *ch = fuse_session_next_chan(f->se, NULL);
  size_t bufsize = fuse_chan_bufsize(ch);
  struct fuse_cmd *cmd = fuse_alloc_cmd(bufsize);
  if (cmd != NULL) {
    int res = fuse_chan_recv(&ch, cmd->buf, bufsize);
    if (res <= 0) {
      free_cmd(cmd);
      if (res < 0 && res != -EINTR && res != -EAGAIN)
        fuse_exit(f);
      return NULL;
    }
    cmd->buflen = res;
    cmd->ch = ch;
  }
  return cmd;
}

int fuse_invalidate(struct fuse *f, const char *path)
{
  (void) f;
  (void) path;
  return -EINVAL;
}

void fuse_exit(struct fuse *f)
{
  fuse_session_exit(f->se);
}

struct fuse_context *fuse_get_context(void)
{
  return &fuse_get_context_internal()->ctx;
}

int fuse_interrupted(void)
{
  return fuse_req_interrupted(fuse_get_context_internal()->req);
}

void fuse_set_getcontext_func(struct fuse_context *(*func)(void))
{
  (void) func;
  /* no-op */
}

enum {
  KEY_HELP,
};

#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("-h",		      KEY_HELP),
  FUSE_OPT_KEY("--help",		      KEY_HELP),
  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("umask=",		      set_mode, 1),
  FUSE_LIB_OPT("umask=%o",	      umask, 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("noforget",              remember, -1),
  FUSE_LIB_OPT("remember=%u",           remember, 0),
  FUSE_LIB_OPT("intr",		      intr, 1),
  FUSE_LIB_OPT("intr_signal=%d",	      intr_signal, 0),
  FUSE_LIB_OPT("threads=%d",            threads, 0),
  FUSE_LIB_OPT("use_ino",               use_ino, 1),
  FUSE_OPT_END
};

static void fuse_lib_help(void)
{
  fprintf(stderr,
          "    -o umask=M             set file permissions (octal)\n"
          "    -o uid=N               set file owner\n"
          "    -o gid=N               set file group\n"
          "    -o noforget            never forget cached inodes\n"
          "    -o remember=T          remember cached inodes for T seconds (0s)\n"
          "    -o intr                allow requests to be interrupted\n"
          "    -o intr_signal=NUM     signal to send on interrupt (%i)\n"
          "    -o threads=NUM         number of worker threads. 0 = autodetect.\n"
          "                           Negative values autodetect then divide by\n"
          "                           absolute value. default = 0\n"
          "\n", FUSE_DEFAULT_INTR_SIGNAL);
}

static int fuse_lib_opt_proc(void *data, const char *arg, int key,
			     struct fuse_args *outargs)
{
  (void) arg; (void) outargs;

  if (key == KEY_HELP) {
    struct fuse_config *conf = (struct fuse_config *) data;
    fuse_lib_help();
    conf->help = 1;
  }

  return 1;
}

int fuse_is_lib_option(const char *opt)
{
  return fuse_lowlevel_is_lib_option(opt) ||
    fuse_opt_match(fuse_lib_opts, opt);
}

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);
}


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) {
    fprintf(stderr, "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) {
    fprintf(stderr, "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) {
    fprintf(stderr, "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;

  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);
  }
}

struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args,
			     const struct fuse_operations *op,
			     size_t op_size, void *user_data)
{
  struct fuse *f;
  struct node *root;
  struct fuse_fs *fs;
  struct fuse_lowlevel_ops llop = fuse_path_ops;

  if (fuse_create_context_key() == -1)
    goto out;

  f = (struct fuse *) calloc(1, sizeof(struct fuse));
  if (f == NULL) {
    fprintf(stderr, "fuse: failed to allocate fuse object\n");
    goto out_delete_context_key;
  }

  fs = fuse_fs_new(op, op_size, user_data);
  if (!fs)
    goto out_free;

  f->fs = fs;

  /* Oh f**k, this is ugly! */
  if (!fs->op.lock) {
    llop.getlk = NULL;
    llop.setlk = NULL;
  }

  f->conf.intr_signal = FUSE_DEFAULT_INTR_SIGNAL;

  f->pagesize = getpagesize();
  init_list_head(&f->partial_slabs);
  init_list_head(&f->full_slabs);
  init_list_head(&f->lru_table);

  if (fuse_opt_parse(args, &f->conf, fuse_lib_opts,
                     fuse_lib_opt_proc) == -1)
    goto out_free_fs;

  f->se = fuse_lowlevel_new_common(args, &llop, sizeof(llop), f);
  if (f->se == NULL) {
    goto out_free_fs;
  }

  fuse_session_add_chan(f->se, ch);

  /* Trace topmost layer by default */
  srand(time(NULL));
  f->fs->debug = f->conf.debug;
  f->ctr = 0;
  f->generation = rand64();
  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;

  fuse_mutex_init(&f->lock);

  root = alloc_node(f);
  if (root == NULL) {
    fprintf(stderr, "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;

  if (f->conf.intr &&
      fuse_init_intr_signal(f->conf.intr_signal,
                            &f->intr_installed) == -1)
    goto out_free_root;

  root->parent = NULL;
  root->nodeid = FUSE_ROOT_ID;
  inc_nlookup(root);
  hash_id(f, root);

  return f;

 out_free_root:
  free(root);
 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:
  /* Horrible compatibility hack to stop the destructor from being
     called on the filesystem without init being called first */
  fs->op.destroy = NULL;
  fuse_fs_destroy(f->fs);
 out_free:
  free(f);
 out_delete_context_key:
  fuse_delete_context_key();
 out:
  return NULL;
}

struct fuse *fuse_new(struct fuse_chan *ch, struct fuse_args *args,
		      const struct fuse_operations *op, size_t op_size,
		      void *user_data)
{
  return fuse_new_common(ch, 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) {
    struct fuse_context_i *c = fuse_get_context_internal();

    memset(c, 0, sizeof(*c));
    c->ctx.fuse = 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)
            fuse_fs_free_hide(f->fs,node->hidden_fh);
        }
    }
  }
  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));

  free(f->id_table.array);
  free(f->name_table.array);
  pthread_mutex_destroy(&f->lock);
  fuse_session_destroy(f->se);
  free(f);
  fuse_delete_context_key();
}

int
fuse_config_num_threads(const struct fuse *fuse_)
{
  return fuse_->conf.threads;
}