change.c 33.6 KB
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/*
 * Server-side change notification management
 *
 * Copyright (C) 1998 Alexandre Julliard
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 * Copyright (C) 2006 Mike McCormack
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 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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 */

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#include "config.h"
#include "wine/port.h"

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#include <assert.h>
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#include <fcntl.h>
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#include <stdio.h>
#include <stdlib.h>
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#include <signal.h>
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#include <sys/stat.h>
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#include <sys/types.h>
#include <limits.h>
#include <dirent.h>
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#include <errno.h>
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#ifdef HAVE_POLL_H
# include <poll.h>
#endif
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#ifdef HAVE_SYS_INOTIFY_H
#include <sys/inotify.h>
#endif
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#include "ntstatus.h"
#define WIN32_NO_STATUS
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#include "windef.h"
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#include "file.h"
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#include "handle.h"
#include "thread.h"
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#include "request.h"
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#include "process.h"
#include "security.h"
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#include "winternl.h"
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/* dnotify support */

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#ifdef linux
#ifndef F_NOTIFY
#define F_NOTIFY 1026
#define DN_ACCESS       0x00000001      /* File accessed */
#define DN_MODIFY       0x00000002      /* File modified */
#define DN_CREATE       0x00000004      /* File created */
#define DN_DELETE       0x00000008      /* File removed */
#define DN_RENAME       0x00000010      /* File renamed */
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#define DN_ATTRIB       0x00000020      /* File changed attributes */
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#define DN_MULTISHOT    0x80000000      /* Don't remove notifier */
#endif
#endif

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/* inotify support */

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struct inode;

static void free_inode( struct inode *inode );

static struct fd *inotify_fd;

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struct change_record {
    struct list entry;
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    unsigned int cookie;
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    struct filesystem_event event;
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};

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struct dir
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{
    struct object  obj;      /* object header */
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    struct fd     *fd;       /* file descriptor to the directory */
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    mode_t         mode;     /* file stat.st_mode */
    uid_t          uid;      /* file stat.st_uid */
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    struct list    entry;    /* entry in global change notifications list */
    unsigned int   filter;   /* notification filter */
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    volatile int   notified; /* SIGIO counter */
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    int            want_data; /* return change data */
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    int            subtree;  /* do we want to watch subdirectories? */
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    struct list    change_records;   /* data for the change */
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    struct list    in_entry; /* entry in the inode dirs list */
    struct inode  *inode;    /* inode of the associated directory */
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    struct process *client_process;  /* client process that has a cache for this directory */
    int             client_entry;    /* entry in client process cache */
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};

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static struct fd *dir_get_fd( struct object *obj );
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static struct security_descriptor *dir_get_sd( struct object *obj );
static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
                       unsigned int set_info );
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static void dir_dump( struct object *obj, int verbose );
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static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle );
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static void dir_destroy( struct object *obj );
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static const struct object_ops dir_ops =
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{
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    sizeof(struct dir),       /* size */
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    &file_type,               /* type */
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    dir_dump,                 /* dump */
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    add_queue,                /* add_queue */
    remove_queue,             /* remove_queue */
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    default_fd_signaled,      /* signaled */
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    no_satisfied,             /* satisfied */
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    no_signal,                /* signal */
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    dir_get_fd,               /* get_fd */
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    default_map_access,       /* map_access */
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    dir_get_sd,               /* get_sd */
    dir_set_sd,               /* set_sd */
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    no_get_full_name,         /* get_full_name */
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    no_lookup_name,           /* lookup_name */
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    no_link_name,             /* link_name */
    NULL,                     /* unlink_name */
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    no_open_file,             /* open_file */
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    no_kernel_obj_list,       /* get_kernel_obj_list */
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    dir_close_handle,         /* close_handle */
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    dir_destroy               /* destroy */
};

static int dir_get_poll_events( struct fd *fd );
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static enum server_fd_type dir_get_fd_type( struct fd *fd );
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static const struct fd_ops dir_fd_ops =
{
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    dir_get_poll_events,         /* get_poll_events */
    default_poll_event,          /* poll_event */
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    dir_get_fd_type,             /* get_fd_type */
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    no_fd_read,                  /* read */
    no_fd_write,                 /* write */
    no_fd_flush,                 /* flush */
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    default_fd_get_file_info,    /* get_file_info */
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    no_fd_get_volume_info,       /* get_volume_info */
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    default_fd_ioctl,            /* ioctl */
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    default_fd_queue_async,      /* queue_async */
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    default_fd_reselect_async    /* reselect_async */
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};

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static struct list change_list = LIST_INIT(change_list);

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/* per-process structure to keep track of cache entries on the client size */
struct dir_cache
{
    unsigned int  size;
    unsigned int  count;
    unsigned char state[1];
};

enum dir_cache_state
{
    DIR_CACHE_STATE_FREE,
    DIR_CACHE_STATE_INUSE,
    DIR_CACHE_STATE_RELEASED
};

/* return an array of cache entries that can be freed on the client side */
static int *get_free_dir_cache_entries( struct process *process, data_size_t *size )
{
    int *ret;
    struct dir_cache *cache = process->dir_cache;
    unsigned int i, j, count;

    if (!cache) return NULL;
    for (i = count = 0; i < cache->count && count < *size / sizeof(*ret); i++)
        if (cache->state[i] == DIR_CACHE_STATE_RELEASED) count++;
    if (!count) return NULL;

    if ((ret = malloc( count * sizeof(*ret) )))
    {
        for (i = j = 0; j < count; i++)
        {
            if (cache->state[i] != DIR_CACHE_STATE_RELEASED) continue;
            cache->state[i] = DIR_CACHE_STATE_FREE;
            ret[j++] = i;
        }
        *size = count * sizeof(*ret);
    }
    return ret;
}

/* allocate a new client-side directory cache entry */
static int alloc_dir_cache_entry( struct dir *dir, struct process *process )
{
    unsigned int i = 0;
    struct dir_cache *cache = process->dir_cache;

    if (cache)
        for (i = 0; i < cache->count; i++)
            if (cache->state[i] == DIR_CACHE_STATE_FREE) goto found;

    if (!cache || cache->count == cache->size)
    {
        unsigned int size = cache ? cache->size * 2 : 256;
        if (!(cache = realloc( cache, offsetof( struct dir_cache, state[size] ))))
        {
            set_error( STATUS_NO_MEMORY );
            return -1;
        }
        process->dir_cache = cache;
        cache->size = size;
    }
    cache->count = i + 1;

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    cache->state[i] = DIR_CACHE_STATE_INUSE;
    return i;
}

/* release a directory cache entry; it will be freed on the client side on the next cache request */
static void release_dir_cache_entry( struct dir *dir )
{
    struct dir_cache *cache;

    if (!dir->client_process) return;
    cache = dir->client_process->dir_cache;
    cache->state[dir->client_entry] = DIR_CACHE_STATE_RELEASED;
    release_object( dir->client_process );
    dir->client_process = NULL;
}

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static void dnotify_adjust_changes( struct dir *dir )
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{
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#if defined(F_SETSIG) && defined(F_NOTIFY)
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    int fd = get_unix_fd( dir->fd );
    unsigned int filter = dir->filter;
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    unsigned int val;
    if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
        return;

    val = DN_MULTISHOT;
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    if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
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        val |= DN_RENAME | DN_DELETE | DN_CREATE;
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    if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
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        val |= DN_RENAME | DN_DELETE | DN_CREATE;
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    if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
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        val |= DN_ATTRIB;
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    if (filter & FILE_NOTIFY_CHANGE_SIZE)
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        val |= DN_MODIFY;
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    if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
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        val |= DN_MODIFY;
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    if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
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        val |= DN_ACCESS;
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    if (filter & FILE_NOTIFY_CHANGE_CREATION)
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        val |= DN_CREATE;
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    if (filter & FILE_NOTIFY_CHANGE_SECURITY)
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        val |= DN_ATTRIB;
    fcntl( fd, F_NOTIFY, val );
#endif
}

/* insert change in the global list */
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static inline void insert_change( struct dir *dir )
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{
    sigset_t sigset;

    sigemptyset( &sigset );
    sigaddset( &sigset, SIGIO );
    sigprocmask( SIG_BLOCK, &sigset, NULL );
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    list_add_head( &change_list, &dir->entry );
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    sigprocmask( SIG_UNBLOCK, &sigset, NULL );
}

/* remove change from the global list */
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static inline void remove_change( struct dir *dir )
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{
    sigset_t sigset;

    sigemptyset( &sigset );
    sigaddset( &sigset, SIGIO );
    sigprocmask( SIG_BLOCK, &sigset, NULL );
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    list_remove( &dir->entry );
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    sigprocmask( SIG_UNBLOCK, &sigset, NULL );
}
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static void dir_dump( struct object *obj, int verbose )
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{
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    struct dir *dir = (struct dir *)obj;
    assert( obj->ops == &dir_ops );
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    fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
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}

/* enter here directly from SIGIO signal handler */
void do_change_notify( int unix_fd )
{
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    struct dir *dir;
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    /* FIXME: this is O(n) ... probably can be improved */
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    LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
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    {
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        if (get_unix_fd( dir->fd ) != unix_fd) continue;
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        dir->notified = 1;
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        break;
    }
}

/* SIGIO callback, called synchronously with the poll loop */
void sigio_callback(void)
{
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    struct dir *dir;
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    LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
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    {
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        if (!dir->notified) continue;
        dir->notified = 0;
        fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
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    }
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}

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static struct fd *dir_get_fd( struct object *obj )
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{
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    struct dir *dir = (struct dir *)obj;
    assert( obj->ops == &dir_ops );
    return (struct fd *)grab_object( dir->fd );
}
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static int get_dir_unix_fd( struct dir *dir )
{
    return get_unix_fd( dir->fd );
}

static struct security_descriptor *dir_get_sd( struct object *obj )
{
    struct dir *dir = (struct dir *)obj;
    int unix_fd;
    struct stat st;
    struct security_descriptor *sd;
    assert( obj->ops == &dir_ops );

    unix_fd = get_dir_unix_fd( dir );

    if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
        return obj->sd;

    /* mode and uid the same? if so, no need to re-generate security descriptor */
    if (obj->sd &&
        (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
        (st.st_uid == dir->uid))
        return obj->sd;

    sd = mode_to_sd( st.st_mode,
                     security_unix_uid_to_sid( st.st_uid ),
                     token_get_primary_group( current->process->token ));
    if (!sd) return obj->sd;

    dir->mode = st.st_mode;
    dir->uid = st.st_uid;
    free( obj->sd );
    obj->sd = sd;
    return sd;
}

static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
                       unsigned int set_info )
{
    struct dir *dir = (struct dir *)obj;
    const SID *owner;
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    struct stat st;
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    mode_t mode;
    int unix_fd;

    assert( obj->ops == &dir_ops );

    unix_fd = get_dir_unix_fd( dir );

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    if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
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    if (set_info & OWNER_SECURITY_INFORMATION)
    {
        owner = sd_get_owner( sd );
        if (!owner)
        {
            set_error( STATUS_INVALID_SECURITY_DESCR );
            return 0;
        }
        if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
        {
            /* FIXME: get Unix uid and call fchown */
        }
    }
    else if (obj->sd)
        owner = sd_get_owner( obj->sd );
    else
        owner = token_get_user( current->process->token );

    if (set_info & DACL_SECURITY_INFORMATION)
    {
        /* keep the bits that we don't map to access rights in the ACL */
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        mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
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        mode |= sd_to_mode( sd, owner );

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        if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
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        {
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            file_set_error();
            return 0;
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        }
    }
    return 1;
}

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static struct change_record *get_first_change_record( struct dir *dir )
{
    struct list *ptr = list_head( &dir->change_records );
    if (!ptr) return NULL;
    list_remove( ptr );
    return LIST_ENTRY( ptr, struct change_record, entry );
}

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static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
{
    struct dir *dir = (struct dir *)obj;

    if (!fd_close_handle( obj, process, handle )) return 0;
    if (obj->handle_count == 1) release_dir_cache_entry( dir ); /* closing last handle, release cache */
    return 1;  /* ok to close */
}

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static void dir_destroy( struct object *obj )
{
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    struct change_record *record;
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    struct dir *dir = (struct dir *)obj;
    assert (obj->ops == &dir_ops);
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    if (dir->filter)
        remove_change( dir );

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    if (dir->inode)
    {
        list_remove( &dir->in_entry );
        free_inode( dir->inode );
    }
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    while ((record = get_first_change_record( dir ))) free( record );

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    release_dir_cache_entry( dir );
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    release_object( dir->fd );
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    if (inotify_fd && list_empty( &change_list ))
    {
        release_object( inotify_fd );
        inotify_fd = NULL;
    }
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}

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struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
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{
    return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
}

static int dir_get_poll_events( struct fd *fd )
{
    return 0;
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}

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static enum server_fd_type dir_get_fd_type( struct fd *fd )
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{
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    return FD_TYPE_DIR;
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}

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#ifdef HAVE_SYS_INOTIFY_H
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#define HASH_SIZE 31

struct inode {
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    struct list ch_entry;    /* entry in the children list */
    struct list children;    /* children of this inode */
    struct inode *parent;    /* parent of this inode */
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    struct list dirs;        /* directory handles watching this inode */
    struct list ino_entry;   /* entry in the inode hash */
    struct list wd_entry;    /* entry in the watch descriptor hash */
    dev_t dev;               /* device number */
    ino_t ino;               /* device's inode number */
    int wd;                  /* inotify's watch descriptor */
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    char *name;              /* basename name of the inode */
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};

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static struct list inode_hash[ HASH_SIZE ];
static struct list wd_hash[ HASH_SIZE ];
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static int inotify_add_dir( char *path, unsigned int filter );

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static struct inode *inode_from_wd( int wd )
{
    struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
    struct inode *inode;

    LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
        if (inode->wd == wd)
            return inode;

    return NULL;
}

static inline struct list *get_hash_list( dev_t dev, ino_t ino )
{
    return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
}

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static struct inode *find_inode( dev_t dev, ino_t ino )
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{
    struct list *bucket = get_hash_list( dev, ino );
    struct inode *inode;

    LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
        if (inode->ino == ino && inode->dev == dev)
             return inode;

    return NULL;
}

static struct inode *create_inode( dev_t dev, ino_t ino )
{
    struct inode *inode;

    inode = malloc( sizeof *inode );
    if (inode)
    {
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        list_init( &inode->children );
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        list_init( &inode->dirs );
        inode->ino = ino;
        inode->dev = dev;
        inode->wd = -1;
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        inode->parent = NULL;
        inode->name = NULL;
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        list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
    }
    return inode;
}

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static struct inode *get_inode( dev_t dev, ino_t ino )
{
    struct inode *inode;

    inode = find_inode( dev, ino );
    if (inode)
        return inode;
    return create_inode( dev, ino );
}

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static void inode_set_wd( struct inode *inode, int wd )
{
    if (inode->wd != -1)
        list_remove( &inode->wd_entry );
    inode->wd = wd;
    list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
}

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static void inode_set_name( struct inode *inode, const char *name )
{
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    free (inode->name);
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    inode->name = name ? strdup( name ) : NULL;
}

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static void free_inode( struct inode *inode )
{
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    int subtree = 0, watches = 0;
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    struct inode *tmp, *next;
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    struct dir *dir;

    LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
    {
        subtree |= dir->subtree;
        watches++;
    }

    if (!subtree && !inode->parent)
    {
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        LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
                                  struct inode, ch_entry )
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        {
            assert( tmp != inode );
            assert( tmp->parent == inode );
            free_inode( tmp );
        }
    }

    if (watches)
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        return;

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    if (inode->parent)
        list_remove( &inode->ch_entry );

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    /* disconnect remaining children from the parent */
    LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
    {
        list_remove( &tmp->ch_entry );
        tmp->parent = NULL;
    }

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    if (inode->wd != -1)
    {
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        inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
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        list_remove( &inode->wd_entry );
    }
    list_remove( &inode->ino_entry );
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    free( inode->name );
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    free( inode );
}

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static struct inode *inode_add( struct inode *parent,
                                dev_t dev, ino_t ino, const char *name )
{
    struct inode *inode;
 
    inode = get_inode( dev, ino );
    if (!inode)
        return NULL;
 
    if (!inode->parent)
    {
        list_add_tail( &parent->children, &inode->ch_entry );
        inode->parent = parent;
        assert( inode != parent );
    }
    inode_set_name( inode, name );

    return inode;
}

static struct inode *inode_from_name( struct inode *inode, const char *name )
{
    struct inode *i;

    LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
        if (i->name && !strcmp( i->name, name ))
            return i;
    return NULL;
}

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static int inotify_get_poll_events( struct fd *fd );
static void inotify_poll_event( struct fd *fd, int event );

static const struct fd_ops inotify_fd_ops =
{
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    inotify_get_poll_events,     /* get_poll_events */
    inotify_poll_event,          /* poll_event */
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    NULL,                        /* flush */
    NULL,                        /* get_fd_type */
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    NULL,                        /* ioctl */
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    NULL,                        /* queue_async */
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    NULL                         /* reselect_async */
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};

static int inotify_get_poll_events( struct fd *fd )
{
    return POLLIN;
}

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static void inotify_do_change_notify( struct dir *dir, unsigned int action,
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                                      unsigned int cookie, const char *relpath )
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{
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    struct change_record *record;

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    assert( dir->obj.ops == &dir_ops );

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    if (dir->want_data)
    {
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        size_t len = strlen(relpath);
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        record = malloc( offsetof(struct change_record, event.name[len]) );
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        if (!record)
            return;

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        record->cookie = cookie;
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        record->event.action = action;
        memcpy( record->event.name, relpath, len );
        record->event.len = len;
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        list_add_tail( &dir->change_records, &record->entry );
    }
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    fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
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}

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static unsigned int filter_from_event( struct inotify_event *ie )
{
    unsigned int filter = 0;

    if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
        filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
    if (ie->mask & IN_MODIFY)
693
        filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE | FILE_NOTIFY_CHANGE_LAST_ACCESS;
694 695 696 697 698
    if (ie->mask & IN_ATTRIB)
        filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
    if (ie->mask & IN_CREATE)
        filter |= FILE_NOTIFY_CHANGE_CREATION;

699 700 701 702 703
    if (ie->mask & IN_ISDIR)
        filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
    else
        filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;

704 705 706
    return filter;
}

707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726
/* scan up the parent directories for watches */
static unsigned int filter_from_inode( struct inode *inode, int is_parent )
{
    unsigned int filter = 0;
    struct dir *dir;

    /* combine filters from parents watching subtrees */
    while (inode)
    {
        LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
            if (dir->subtree || !is_parent)
                filter |= dir->filter;
        is_parent = 1;
        inode = inode->parent;
    }

    return filter;
}

static char *inode_get_path( struct inode *inode, int sz )
727 728
{
    struct list *head;
729 730 731 732 733
    char *path;
    int len;

    if (!inode)
        return NULL;
734 735

    head = list_head( &inode->dirs );
736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758
    if (head)
    {
        int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
        path = malloc ( 32 + sz );
        if (path)
            sprintf( path, "/proc/self/fd/%u/", unix_fd );
        return path;
    }

    if (!inode->name)
        return NULL;

    len = strlen( inode->name );
    path = inode_get_path( inode->parent, sz + len + 1 );
    if (!path)
        return NULL;
    
    strcat( path, inode->name );
    strcat( path, "/" );

    return path;
}

759
static void inode_check_dir( struct inode *parent, const char *name )
760 761 762 763 764
{
    char *path;
    unsigned int filter;
    struct inode *inode;
    struct stat st;
765
    int wd = -1;
766

767
    path = inode_get_path( parent, strlen(name) );
768
    if (!path)
769
        return;
770 771

    strcat( path, name );
772

773
    if (stat( path, &st ) < 0)
774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790
        goto end;

    filter = filter_from_inode( parent, 1 );
    if (!filter)
        goto end;

    inode = inode_add( parent, st.st_dev, st.st_ino, name );
    if (!inode || inode->wd != -1)
        goto end;

    wd = inotify_add_dir( path, filter );
    if (wd != -1)
        inode_set_wd( inode, wd );
    else
        free_inode( inode );

end:
791
    free( path );
792
}
793

794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818
static int prepend( char **path, const char *segment )
{
    int extra;
    char *p;

    extra = strlen( segment ) + 1;
    if (*path)
    {
        int len = strlen( *path ) + 1;
        p = realloc( *path, len + extra );
        if (!p) return 0;
        memmove( &p[ extra ], p, len );
        p[ extra - 1 ] = '/';
        memcpy( p, segment, extra - 1 );
    }
    else
    {
        p = malloc( extra );
        if (!p) return 0;
        memcpy( p, segment, extra );
    }

    *path = p;

    return 1;
819 820
}

821 822
static void inotify_notify_all( struct inotify_event *ie )
{
823
    unsigned int filter, action;
824 825
    struct inode *inode, *i;
    char *path = NULL;
826 827 828 829 830 831 832 833 834 835
    struct dir *dir;

    inode = inode_from_wd( ie->wd );
    if (!inode)
    {
        fprintf( stderr, "no inode matches %d\n", ie->wd);
        return;
    }

    filter = filter_from_event( ie );
836 837 838
    
    if (ie->mask & IN_CREATE)
    {
839 840 841
        if (ie->mask & IN_ISDIR)
            inode_check_dir( inode, ie->name );

842 843 844 845
        action = FILE_ACTION_ADDED;
    }
    else if (ie->mask & IN_DELETE)
        action = FILE_ACTION_REMOVED;
846 847 848 849
    else if (ie->mask & IN_MOVED_FROM)
        action = FILE_ACTION_RENAMED_OLD_NAME;
    else if (ie->mask & IN_MOVED_TO)
        action = FILE_ACTION_RENAMED_NEW_NAME;
850 851
    else
        action = FILE_ACTION_MODIFIED;
852

853
    /*
854
     * Work our way up the inode hierarchy
855
     *  extending the relative path as we go
856
     *  and notifying all recursive watches.
857 858 859 860 861 862 863 864
     */
    if (!prepend( &path, ie->name ))
        return;

    for (i = inode; i; i = i->parent)
    {
        LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
            if ((filter & dir->filter) && (i==inode || dir->subtree))
865
                inotify_do_change_notify( dir, action, ie->cookie, path );
866 867 868 869 870 871 872 873 874 875 876 877 878

        if (!i->name || !prepend( &path, i->name ))
            break;
    }

    free( path );

    if (ie->mask & IN_DELETE)
    {
        i = inode_from_name( inode, ie->name );
        if (i)
            free_inode( i );
    }
879 880
}

881 882 883 884 885 886 887 888 889 890 891 892 893 894
static void inotify_poll_event( struct fd *fd, int event )
{
    int r, ofs, unix_fd;
    char buffer[0x1000];
    struct inotify_event *ie;

    unix_fd = get_unix_fd( fd );
    r = read( unix_fd, buffer, sizeof buffer );
    if (r < 0)
    {
        fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
        return;
    }

895
    for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
896 897
    {
        ie = (struct inotify_event*) &buffer[ofs];
898 899
        ofs += offsetof( struct inotify_event, name[ie->len] );
        if (ofs > r) break;
900
        if (ie->len) inotify_notify_all( ie );
901 902 903
    }
}

904
static inline struct fd *create_inotify_fd( void )
905 906 907 908 909 910
{
    int unix_fd;

    unix_fd = inotify_init();
    if (unix_fd<0)
        return NULL;
911
    return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
912 913
}

914
static int map_flags( unsigned int filter )
915
{
916 917 918 919
    unsigned int mask;

    /* always watch these so we can track subdirectories in recursive watches */
    mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
920

921 922 923 924 925 926 927
    if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
        mask |= IN_ATTRIB;
    if (filter & FILE_NOTIFY_CHANGE_SIZE)
        mask |= IN_MODIFY;
    if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
        mask |= IN_MODIFY;
    if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
928
        mask |= IN_MODIFY;
929 930 931
    if (filter & FILE_NOTIFY_CHANGE_SECURITY)
        mask |= IN_ATTRIB;

932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992
    return mask;
}

static int inotify_add_dir( char *path, unsigned int filter )
{
    int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
                                path, map_flags( filter ) );
    if (wd != -1)
        set_fd_events( inotify_fd, POLLIN );
    return wd;
}

static int init_inotify( void )
{
    int i;

    if (inotify_fd)
        return 1;

    inotify_fd = create_inotify_fd();
    if (!inotify_fd)
        return 0;

    for (i=0; i<HASH_SIZE; i++)
    {
        list_init( &inode_hash[i] );
        list_init( &wd_hash[i] );
    }

    return 1;
}

static int inotify_adjust_changes( struct dir *dir )
{
    unsigned int filter;
    struct inode *inode;
    struct stat st;
    char path[32];
    int wd, unix_fd;

    if (!inotify_fd)
        return 0;

    unix_fd = get_unix_fd( dir->fd );

    inode = dir->inode;
    if (!inode)
    {
        /* check if this fd is already being watched */
        if (-1 == fstat( unix_fd, &st ))
            return 0;

        inode = get_inode( st.st_dev, st.st_ino );
        if (!inode)
            inode = create_inode( st.st_dev, st.st_ino );
        if (!inode)
            return 0;
        list_add_tail( &inode->dirs, &dir->in_entry );
        dir->inode = inode;
    }

993
    filter = filter_from_inode( inode, 0 );
994 995 996 997 998 999 1000

    sprintf( path, "/proc/self/fd/%u", unix_fd );
    wd = inotify_add_dir( path, filter );
    if (wd == -1) return 0;

    inode_set_wd( inode, wd );

1001
    return 1;
1002 1003
}

1004 1005 1006 1007 1008 1009 1010 1011
static char *get_basename( const char *link )
{
    char *buffer, *name = NULL;
    int r, n = 0x100;

    while (1)
    {
        buffer = malloc( n );
1012
        if (!buffer) return NULL;
1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102

        r = readlink( link, buffer, n );
        if (r < 0)
            break;

        if (r < n)
        {
            name = buffer;
            break;
        }
        free( buffer );
        n *= 2;
    }

    if (name)
    {
        while (r > 0 && name[ r - 1 ] == '/' )
            r--;
        name[ r ] = 0;

        name = strrchr( name, '/' );
        if (name)
            name = strdup( &name[1] );
    }

    free( buffer );
    return name;
}

static int dir_add_to_existing_notify( struct dir *dir )
{
    struct inode *inode, *parent;
    unsigned int filter = 0;
    struct stat st, st_new;
    char link[35], *name;
    int wd, unix_fd;

    if (!inotify_fd)
        return 0;

    unix_fd = get_unix_fd( dir->fd );

    /* check if it's in the list of inodes we want to watch */
    if (-1 == fstat( unix_fd, &st_new ))
        return 0;
    inode = find_inode( st_new.st_dev, st_new.st_ino );
    if (inode)
        return 0;

    /* lookup the parent */
    sprintf( link, "/proc/self/fd/%u/..", unix_fd );
    if (-1 == stat( link, &st ))
        return 0;

    /*
     * If there's no parent, stop.  We could keep going adding
     *  ../ to the path until we hit the root of the tree or
     *  find a recursively watched ancestor.
     * Assume it's too expensive to search up the tree for now.
     */
    parent = find_inode( st.st_dev, st.st_ino );
    if (!parent)
        return 0;

    if (parent->wd == -1)
        return 0;

    filter = filter_from_inode( parent, 1 );
    if (!filter)
        return 0;

    sprintf( link, "/proc/self/fd/%u", unix_fd );
    name = get_basename( link );
    if (!name)
        return 0;
    inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
    free( name );
    if (!inode)
        return 0;

    /* Couldn't find this inode at the start of the function, must be new */
    assert( inode->wd == -1 );

    wd = inotify_add_dir( link, filter );
    if (wd != -1)
        inode_set_wd( inode, wd );

    return 1;
}

1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119
#else

static int init_inotify( void )
{
    return 0;
}

static int inotify_adjust_changes( struct dir *dir )
{
    return 0;
}

static void free_inode( struct inode *inode )
{
    assert( 0 );
}

1120 1121 1122 1123 1124
static int dir_add_to_existing_notify( struct dir *dir )
{
    return 0;
}

1125
#endif  /* HAVE_SYS_INOTIFY_H */
1126

1127
struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
{
    struct dir *dir;

    dir = alloc_object( &dir_ops );
    if (!dir)
        return NULL;

    list_init( &dir->change_records );
    dir->filter = 0;
    dir->notified = 0;
    dir->want_data = 0;
    dir->inode = NULL;
    grab_object( fd );
    dir->fd = fd;
1142 1143
    dir->mode = mode;
    dir->uid  = ~(uid_t)0;
1144
    dir->client_process = NULL;
1145 1146
    set_fd_user( fd, &dir_fd_ops, &dir->obj );

1147 1148
    dir_add_to_existing_notify( dir );

1149 1150 1151
    return &dir->obj;
}

1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
/* retrieve (or allocate) the client-side directory cache entry */
DECL_HANDLER(get_directory_cache_entry)
{
    struct dir *dir;
    int *free_entries;
    data_size_t free_size;

    if (!(dir = get_dir_obj( current->process, req->handle, 0 ))) return;

    if (!dir->client_process)
    {
        if ((dir->client_entry = alloc_dir_cache_entry( dir, current->process )) == -1) goto done;
        dir->client_process = (struct process *)grab_object( current->process );
    }

    if (dir->client_process == current->process) reply->entry = dir->client_entry;
    else set_error( STATUS_SHARING_VIOLATION );

done:  /* allow freeing entries even on failure */
    free_size = get_reply_max_size();
    free_entries = get_free_dir_cache_entries( current->process, &free_size );
    if (free_entries) set_reply_data_ptr( free_entries, free_size );

    release_object( dir );
}

1178 1179 1180 1181
/* enable change notifications for a directory */
DECL_HANDLER(read_directory_changes)
{
    struct dir *dir;
1182
    struct async *async;
1183 1184 1185 1186 1187 1188 1189

    if (!req->filter)
    {
        set_error(STATUS_INVALID_PARAMETER);
        return;
    }

1190
    dir = get_dir_obj( current->process, req->async.handle, 0 );
1191 1192
    if (!dir)
        return;
1193

1194
    /* requests don't timeout */
1195
    if (!(async = create_async( dir->fd, current, &req->async, NULL ))) goto end;
1196
    fd_queue_async( dir->fd, async, ASYNC_TYPE_WAIT );
1197

1198 1199 1200
    /* assign it once */
    if (!dir->filter)
    {
1201
        init_inotify();
1202 1203
        insert_change( dir );
        dir->filter = req->filter;
1204
        dir->subtree = req->subtree;
1205
        dir->want_data = req->want_data;
1206 1207
    }

1208
    /* if there's already a change in the queue, send it */
1209
    if (!list_empty( &dir->change_records ))
1210
        fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1211

1212
    /* setup the real notification */
1213
    if (!inotify_adjust_changes( dir ))
1214
        dnotify_adjust_changes( dir );
1215 1216 1217

    set_error(STATUS_PENDING);

1218
    release_object( async );
1219 1220
end:
    release_object( dir );
1221
}
1222 1223 1224

DECL_HANDLER(read_change)
{
1225
    struct change_record *record, *next;
1226
    struct dir *dir;
1227 1228 1229
    struct list events;
    char *data, *event;
    int size = 0;
1230 1231 1232 1233 1234

    dir = get_dir_obj( current->process, req->handle, 0 );
    if (!dir)
        return;

1235 1236 1237 1238 1239
    list_init( &events );
    list_move_tail( &events, &dir->change_records );
    release_object( dir );

    if (list_empty( &events ))
1240 1241
    {
        set_error( STATUS_NO_DATA_DETECTED );
1242 1243
        return;
    }
1244

1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258
    LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
    {
        size += (offsetof(struct filesystem_event, name[record->event.len])
                + sizeof(int)-1) / sizeof(int) * sizeof(int);
    }

    if (size > get_reply_max_size())
        set_error( STATUS_BUFFER_TOO_SMALL );
    else if ((data = mem_alloc( size )) != NULL)
    {
        event = data;
        LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
        {
            data_size_t len = offsetof( struct filesystem_event, name[record->event.len] );
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274

            /* FIXME: rename events are sometimes reported as delete/create */
            if (record->event.action == FILE_ACTION_RENAMED_OLD_NAME)
            {
                struct list *elem = list_next( &events, &record->entry );
                if (elem)
                    next = LIST_ENTRY(elem, struct change_record, entry);

                if (elem && next->cookie == record->cookie)
                    next->cookie = 0;
                else
                    record->event.action = FILE_ACTION_REMOVED;
            }
            else if (record->event.action == FILE_ACTION_RENAMED_NEW_NAME && record->cookie)
                record->event.action = FILE_ACTION_ADDED;

1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
            memcpy( event, &record->event, len );
            event += len;
            if (len % sizeof(int))
            {
                memset( event, 0, sizeof(int) - len % sizeof(int) );
                event += sizeof(int) - len % sizeof(int);
            }
        }
        set_reply_data_ptr( data, size );
    }

    LIST_FOR_EACH_ENTRY_SAFE( record, next, &events, struct change_record, entry )
    {
        list_remove( &record->entry );
        free( record );
    }
1291
}