change.c 29.6 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>
#ifdef HAVE_SYS_ERRNO_H
#include <sys/errno.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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#ifdef HAVE_SYS_INOTIFY_H
#include <sys/inotify.h>
#define USE_INOTIFY
#elif defined(__linux__) && defined(__i386__)
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#define SYS_inotify_init	291
#define SYS_inotify_add_watch	292
#define SYS_inotify_rm_watch	293

struct inotify_event {
    int           wd;
    unsigned int  mask;
    unsigned int  cookie;
    unsigned int  len;
    char          name[1];
};

#define IN_ACCESS        0x00000001
#define IN_MODIFY        0x00000002
#define IN_ATTRIB        0x00000004
#define IN_CLOSE_WRITE   0x00000008
#define IN_CLOSE_NOWRITE 0x00000010
#define IN_OPEN          0x00000020
#define IN_MOVED_FROM    0x00000040
#define IN_MOVED_TO      0x00000080
#define IN_CREATE        0x00000100
#define IN_DELETE        0x00000200
#define IN_DELETE_SELF   0x00000400

static inline int inotify_init( void )
{
    int ret;
    __asm__ __volatile__( "int $0x80"
                          : "=a" (ret)
                          : "0" (SYS_inotify_init));
    if (ret<0) { errno = -ret; ret = -1; }
    return ret;
}

static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
{
    int ret;
    __asm__ __volatile__( "pushl %%ebx;\n\t"
                          "movl %2,%%ebx;\n\t"
                          "int $0x80;\n\t"
                          "popl %%ebx"
                          : "=a" (ret) : "0" (SYS_inotify_add_watch),
                            "r" (fd), "c" (name), "d" (mask) );
    if (ret<0) { errno = -ret; ret = -1; }
    return ret;
}

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static inline int inotify_rm_watch( int fd, int wd )
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{
    int ret;
    __asm__ __volatile__( "pushl %%ebx;\n\t"
                          "movl %2,%%ebx;\n\t"
                          "int $0x80;\n\t"
                          "popl %%ebx"
                          : "=a" (ret) : "0" (SYS_inotify_rm_watch),
                            "r" (fd), "c" (wd) );
    if (ret<0) { errno = -ret; ret = -1; }
    return ret;
}

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#define USE_INOTIFY
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#endif

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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;
    int action;
    int len;
    char name[1];
};

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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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    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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};

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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 );
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 */
    dir_dump,                 /* dump */
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    no_get_type,              /* get_type */
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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_fd_map_access,    /* map_access */
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    dir_get_sd,               /* get_sd */
    dir_set_sd,               /* set_sd */
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    no_lookup_name,           /* lookup_name */
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    no_open_file,             /* open_file */
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    fd_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 */
    no_flush,                    /* flush */
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    dir_get_fd_type,             /* get_fd_type */
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    default_fd_ioctl,            /* ioctl */
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    default_fd_queue_async,      /* queue_async */
    default_fd_reselect_async,   /* reselect_async */
    default_fd_cancel_async      /* cancel_async */
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};

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static struct list change_list = LIST_INIT(change_list);

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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;
        interlocked_xchg_add( &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 (interlocked_xchg( &dir->notified, 0 ))
            fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
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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;
    mode_t mode;
    int unix_fd;

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

    unix_fd = get_dir_unix_fd( dir );

    if (unix_fd == -1) return 1;

    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 */
        mode = dir->mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG);
        mode |= sd_to_mode( sd, owner );

        if (dir->mode != mode)
        {
            if (fchmod( unix_fd, mode ) == -1)
            {
                file_set_error();
                return 0;
            }

            dir->mode = mode;
        }
    }
    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 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_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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}

static struct dir *
get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
{
    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 USE_INOTIFY

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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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};

struct list inode_hash[ HASH_SIZE ];
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 */
    NULL,                        /* reselect_async */
    NULL,                        /* cancel_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,
                                      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, name[len]) );
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        if (!record)
            return;

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        record->action = action;
        memcpy( record->name, relpath, len );
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        record->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)
        filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
    if (ie->mask & IN_ATTRIB)
        filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
    if (ie->mask & IN_ACCESS)
        filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
    if (ie->mask & IN_CREATE)
        filter |= FILE_NOTIFY_CHANGE_CREATION;

    return filter;
}

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/* 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 )
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{
    struct list *head;
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    char *path;
    int len;

    if (!inode)
        return NULL;
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    head = list_head( &inode->dirs );
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    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;
}

static int inode_check_dir( struct inode *parent, const char *name )
{
    char *path;
    unsigned int filter;
    struct inode *inode;
    struct stat st;
    int wd = -1, r = -1;
734

735
    path = inode_get_path( parent, strlen(name) );
736
    if (!path)
737 738 739
        return r;

    strcat( path, name );
740 741

    r = stat( path, &st );
742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
    if (r < 0) goto end;

    if (!S_ISDIR(st.st_mode))
    {
        r = 0;
        goto end;
    }

    r = 1;

    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:
767
    free( path );
768 769
    return r;
}
770

771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795
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;
796 797
}

798 799
static void inotify_notify_all( struct inotify_event *ie )
{
800
    unsigned int filter, action;
801 802
    struct inode *inode, *i;
    char *path = NULL;
803 804 805 806 807 808 809 810 811 812
    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 );
813 814 815
    
    if (ie->mask & IN_CREATE)
    {
816
        switch (inode_check_dir( inode, ie->name ))
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833
        {
        case 1:
            filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
            break;
        case 0:
            filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
            break;
        default:
            break;
            /* Maybe the file disappeared before we could check it? */
        }
        action = FILE_ACTION_ADDED;
    }
    else if (ie->mask & IN_DELETE)
        action = FILE_ACTION_REMOVED;
    else
        action = FILE_ACTION_MODIFIED;
834

835
    /*
836
     * Work our way up the inode hierarchy
837
     *  extending the relative path as we go
838
     *  and notifying all recursive watches.
839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860
     */
    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))
                inotify_do_change_notify( dir, action, path );

        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 );
    }
861 862
}

863 864 865 866 867 868 869 870 871 872 873 874 875 876
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;
    }

877
    for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
878 879 880 881
    {
        ie = (struct inotify_event*) &buffer[ofs];
        if (!ie->len)
            break;
882 883
        ofs += offsetof( struct inotify_event, name[ie->len] );
        if (ofs > r) break;
884
        inotify_notify_all( ie );
885 886 887
    }
}

888
static inline struct fd *create_inotify_fd( void )
889 890 891 892 893 894
{
    int unix_fd;

    unix_fd = inotify_init();
    if (unix_fd<0)
        return NULL;
895
    return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
896 897
}

898
static int map_flags( unsigned int filter )
899
{
900 901 902 903
    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);
904

905 906 907 908 909 910 911 912 913 914 915
    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)
        mask |= IN_ACCESS;
    if (filter & FILE_NOTIFY_CHANGE_SECURITY)
        mask |= IN_ATTRIB;

916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976
    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;
    }

977
    filter = filter_from_inode( inode, 0 );
978 979 980 981 982 983 984

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

    inode_set_wd( inode, wd );

985
    return 1;
986 987
}

988 989 990 991 992 993 994 995
static char *get_basename( const char *link )
{
    char *buffer, *name = NULL;
    int r, n = 0x100;

    while (1)
    {
        buffer = malloc( n );
996
        if (!buffer) return NULL;
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 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

        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;
}

1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
#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 );
}

1104 1105 1106 1107 1108
static int dir_add_to_existing_notify( struct dir *dir )
{
    return 0;
}

1109
#endif  /* USE_INOTIFY */
1110

1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
struct object *create_dir_obj( struct fd *fd )
{
    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;
    set_fd_user( fd, &dir_fd_ops, &dir->obj );

1128 1129
    dir_add_to_existing_notify( dir );

1130 1131 1132
    return &dir->obj;
}

1133 1134 1135 1136
/* enable change notifications for a directory */
DECL_HANDLER(read_directory_changes)
{
    struct dir *dir;
1137
    struct async *async;
1138 1139 1140 1141 1142 1143 1144

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

1145
    dir = get_dir_obj( current->process, req->async.handle, 0 );
1146 1147
    if (!dir)
        return;
1148

1149
    /* requests don't timeout */
1150
    if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1151

1152 1153 1154
    /* assign it once */
    if (!dir->filter)
    {
1155
        init_inotify();
1156 1157
        insert_change( dir );
        dir->filter = req->filter;
1158
        dir->subtree = req->subtree;
1159
        dir->want_data = req->want_data;
1160 1161
    }

1162
    /* if there's already a change in the queue, send it */
1163
    if (!list_empty( &dir->change_records ))
1164
        fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1165

1166
    /* setup the real notification */
1167
    if (!inotify_adjust_changes( dir ))
1168
        dnotify_adjust_changes( dir );
1169

1170
    release_object( async );
1171 1172 1173 1174
    set_error(STATUS_PENDING);

end:
    release_object( dir );
1175
}
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196

DECL_HANDLER(read_change)
{
    struct change_record *record;
    struct dir *dir;

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

    if ((record = get_first_change_record( dir )) != NULL)
    {
        reply->action = record->action;
        set_reply_data( record->name, record->len );
        free( record );
    }
    else
        set_error( STATUS_NO_DATA_DETECTED );

    release_object( dir );
}