reactos/wine
1
0
Fork 0
mirror of https://github.com/reactos/wine.git synced 2024-12-04 17:56:51 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
6e660bb220
wine/server/change.c

1170 lines
29 KiB
C
Raw Blame History

/*
* Server-side change notification management
*
* Copyright (C) 1998 Alexandre Julliard
* Copyright (C) 2006 Mike McCormack
*
* 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
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include "wine/port.h"
#include <assert.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <limits.h>
#include <dirent.h>
#include <errno.h>
#ifdef HAVE_SYS_ERRNO_H
#include <sys/errno.h>
#endif
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "file.h"
#include "handle.h"
#include "thread.h"
#include "request.h"
#include "winternl.h"
/* dnotify support */
#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 */
#define DN_ATTRIB 0x00000020 /* File changed attibutes */
#define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
#endif
#endif
/* inotify support */
#if defined(__linux__) && defined(__i386__)
#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;
}
static inline int inotify_remove_watch( int fd, int wd )
{
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;
}
#define USE_INOTIFY
#endif
struct inode;
static void free_inode( struct inode *inode );
static struct fd *inotify_fd;
struct change_record {
struct list entry;
int action;
int len;
char name[1];
};
struct dir
{
struct object obj; /* object header */
struct fd *fd; /* file descriptor to the directory */
struct list entry; /* entry in global change notifications list */
struct event *event;
unsigned int filter; /* notification filter */
int notified; /* SIGIO counter */
int want_data; /* return change data */
long signaled; /* the file changed */
int subtree; /* do we want to watch subdirectories? */
struct list change_q; /* change readers */
struct list change_records; /* data for the change */
struct list in_entry; /* entry in the inode dirs list */
struct inode *inode; /* inode of the associated directory */
};
static struct fd *dir_get_fd( struct object *obj );
static unsigned int dir_map_access( struct object *obj, unsigned int access );
static void dir_dump( struct object *obj, int verbose );
static void dir_destroy( struct object *obj );
static int dir_signaled( struct object *obj, struct thread *thread );
static const struct object_ops dir_ops =
{
sizeof(struct dir), /* size */
dir_dump, /* dump */
add_queue, /* add_queue */
remove_queue, /* remove_queue */
dir_signaled, /* signaled */
no_satisfied, /* satisfied */
no_signal, /* signal */
dir_get_fd, /* get_fd */
dir_map_access, /* map_access */
no_lookup_name, /* lookup_name */
no_close_handle, /* close_handle */
dir_destroy /* destroy */
};
static int dir_get_poll_events( struct fd *fd );
static int dir_get_info( struct fd *fd );
static void dir_cancel_async( struct fd *fd );
static const struct fd_ops dir_fd_ops =
{
dir_get_poll_events, /* get_poll_events */
default_poll_event, /* poll_event */
no_flush, /* flush */
dir_get_info, /* get_file_info */
default_fd_queue_async, /* queue_async */
dir_cancel_async /* cancel_async */
};
static struct list change_list = LIST_INIT(change_list);
static void dnotify_adjust_changes( struct dir *dir )
{
#if defined(F_SETSIG) && defined(F_NOTIFY)
int fd = get_unix_fd( dir->fd );
unsigned int filter = dir->filter;
unsigned int val;
if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
return;
val = DN_MULTISHOT;
if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
val |= DN_RENAME | DN_DELETE | DN_CREATE;
if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
val |= DN_RENAME | DN_DELETE | DN_CREATE;
if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
val |= DN_ATTRIB;
if (filter & FILE_NOTIFY_CHANGE_SIZE)
val |= DN_MODIFY;
if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
val |= DN_MODIFY;
if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
val |= DN_ACCESS;
if (filter & FILE_NOTIFY_CHANGE_CREATION)
val |= DN_CREATE;
if (filter & FILE_NOTIFY_CHANGE_SECURITY)
val |= DN_ATTRIB;
fcntl( fd, F_NOTIFY, val );
#endif
}
/* insert change in the global list */
static inline void insert_change( struct dir *dir )
{
sigset_t sigset;
sigemptyset( &sigset );
sigaddset( &sigset, SIGIO );
sigprocmask( SIG_BLOCK, &sigset, NULL );
list_add_head( &change_list, &dir->entry );
sigprocmask( SIG_UNBLOCK, &sigset, NULL );
}
/* remove change from the global list */
static inline void remove_change( struct dir *dir )
{
sigset_t sigset;
sigemptyset( &sigset );
sigaddset( &sigset, SIGIO );
sigprocmask( SIG_BLOCK, &sigset, NULL );
list_remove( &dir->entry );
sigprocmask( SIG_UNBLOCK, &sigset, NULL );
}
static void dir_dump( struct object *obj, int verbose )
{
struct dir *dir = (struct dir *)obj;
assert( obj->ops == &dir_ops );
fprintf( stderr, "Dirfile fd=%p event=%p filter=%08x\n",
dir->fd, dir->event, dir->filter );
}
static int dir_signaled( struct object *obj, struct thread *thread )
{
struct dir *dir = (struct dir *)obj;
assert (obj->ops == &dir_ops);
return (dir->event == NULL) && dir->signaled;
}
/* enter here directly from SIGIO signal handler */
void do_change_notify( int unix_fd )
{
struct dir *dir;
/* FIXME: this is O(n) ... probably can be improved */
LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
{
if (get_unix_fd( dir->fd ) != unix_fd) continue;
interlocked_xchg_add( &dir->notified, 1 );
break;
}
}
static void dir_signal_changed( struct dir *dir )
{
if (dir->event)
set_event( dir->event );
else
wake_up( &dir->obj, 0 );
}
/* SIGIO callback, called synchronously with the poll loop */
void sigio_callback(void)
{
struct dir *dir;
LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
{
long count = interlocked_xchg( &dir->notified, 0 );
if (count)
{
dir->signaled += count;
if (dir->signaled == count) /* was it 0? */
dir_signal_changed( dir );
}
}
}
static struct fd *dir_get_fd( struct object *obj )
{
struct dir *dir = (struct dir *)obj;
assert( obj->ops == &dir_ops );
return (struct fd *)grab_object( dir->fd );
}
static unsigned int dir_map_access( struct object *obj, unsigned int access )
{
if (access & GENERIC_READ) access |= FILE_GENERIC_READ;
if (access & GENERIC_WRITE) access |= FILE_GENERIC_WRITE;
if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
if (access & GENERIC_ALL) access |= FILE_ALL_ACCESS;
return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
}
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 );
}
static void dir_destroy( struct object *obj )
{
struct change_record *record;
struct dir *dir = (struct dir *)obj;
assert (obj->ops == &dir_ops);
if (dir->filter)
remove_change( dir );
if (dir->inode)
{
list_remove( &dir->in_entry );
free_inode( dir->inode );
}
async_terminate_queue( &dir->change_q, STATUS_CANCELLED );
while ((record = get_first_change_record( dir ))) free( record );
if (dir->event)
{
set_event( dir->event );
release_object( dir->event );
}
release_object( dir->fd );
if (inotify_fd && list_empty( &change_list ))
{
release_object( inotify_fd );
inotify_fd = NULL;
}
}
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;
}
static int dir_get_info( struct fd *fd )
{
return 0;
}
static void dir_cancel_async( struct fd *fd )
{
struct dir *dir = (struct dir *) get_fd_user( fd );
async_terminate_queue( &dir->change_q, STATUS_CANCELLED );
}
#ifdef USE_INOTIFY
#define HASH_SIZE 31
struct inode {
struct list ch_entry; /* entry in the children list */
struct list children; /* children of this inode */
struct inode *parent; /* parent of this inode */
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 */
char *name; /* basename name of the inode */
};
struct list inode_hash[ HASH_SIZE ];
struct list wd_hash[ HASH_SIZE ];
static int inotify_add_dir( char *path, unsigned int filter );
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 ];
}
static struct inode *find_inode( dev_t dev, ino_t ino )
{
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)
{
list_init( &inode->children );
list_init( &inode->dirs );
inode->ino = ino;
inode->dev = dev;
inode->wd = -1;
inode->parent = NULL;
inode->name = NULL;
list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
}
return inode;
}
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 );
}
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 );
}
static void inode_set_name( struct inode *inode, const char *name )
{
if (inode->name)
free (inode->name);
inode->name = name ? strdup( name ) : NULL;
}
static void free_inode( struct inode *inode )
{
int subtree = 0, watches = 0;
struct dir *dir;
LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
{
subtree |= dir->subtree;
watches++;
}
if (!subtree && !inode->parent)
{
struct inode *tmp, *next;
LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
struct inode, ch_entry )
{
assert( tmp != inode );
assert( tmp->parent == inode );
free_inode( tmp );
}
}
if (watches)
return;
if (inode->parent)
list_remove( &inode->ch_entry );
if (inode->wd != -1)
{
inotify_remove_watch( get_unix_fd( inotify_fd ), inode->wd );
list_remove( &inode->wd_entry );
}
list_remove( &inode->ino_entry );
free( inode->name );
free( inode );
}
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;
}
static int inotify_get_poll_events( struct fd *fd );
static void inotify_poll_event( struct fd *fd, int event );
static int inotify_get_info( struct fd *fd );
static const struct fd_ops inotify_fd_ops =
{
inotify_get_poll_events, /* get_poll_events */
inotify_poll_event, /* poll_event */
no_flush, /* flush */
inotify_get_info, /* get_file_info */
default_fd_queue_async, /* queue_async */
default_fd_cancel_async, /* cancel_async */
};
static int inotify_get_poll_events( struct fd *fd )
{
return POLLIN;
}
static void inotify_do_change_notify( struct dir *dir, unsigned int action,
const char *relpath )
{
struct change_record *record;
assert( dir->obj.ops == &dir_ops );
if (dir->want_data)
{
size_t len = strlen(relpath);
record = malloc( offsetof(struct change_record, name[len]) );
if (!record)
return;
record->action = action;
memcpy( record->name, relpath, len );
record->len = len;
list_add_tail( &dir->change_records, &record->entry );
}
if (!list_empty( &dir->change_q ))
async_terminate_head( &dir->change_q, STATUS_ALERTED );
}
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;
}
/* 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 )
{
struct list *head;
char *path;
int len;
if (!inode)
return NULL;
head = list_head( &inode->dirs );
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;
path = inode_get_path( parent, strlen(name) );
if (!path)
return r;
strcat( path, name );
r = stat( path, &st );
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:
free( path );
return r;
}
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;
}
static void inotify_notify_all( struct inotify_event *ie )
{
unsigned int filter, action;
struct inode *inode, *i;
char *path = NULL;
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 );
if (ie->mask & IN_CREATE)
{
switch (inode_check_dir( inode, ie->name ))
{
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;
/*
* Work our way up the inode hierarchy
* extending the relative path as we go
* and notifying all recursive watches.
*/
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 );
}
}
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;
}
for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
{
ie = (struct inotify_event*) &buffer[ofs];
if (!ie->len)
break;
ofs += offsetof( struct inotify_event, name[ie->len] );
if (ofs > r) break;
inotify_notify_all( ie );
}
}
static int inotify_get_info( struct fd *fd )
{
return 0;
}
static inline struct fd *create_inotify_fd( void )
{
int unix_fd;
unix_fd = inotify_init();
if (unix_fd<0)
return NULL;
return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL );
}
static int map_flags( unsigned int filter )
{
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);
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;
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;
}
filter = filter_from_inode( inode, 0 );
sprintf( path, "/proc/self/fd/%u", unix_fd );
wd = inotify_add_dir( path, filter );
if (wd == -1) return 0;
inode_set_wd( inode, wd );
return 1;
}
static char *get_basename( const char *link )
{
char *buffer, *name = NULL;
int r, n = 0x100;
while (1)
{
buffer = malloc( n );
if (!buffer) return NULL;
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;
}
#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 );
}
static int dir_add_to_existing_notify( struct dir *dir )
{
return 0;
}
#endif /* USE_INOTIFY */
struct object *create_dir_obj( struct fd *fd )
{
struct dir *dir;
dir = alloc_object( &dir_ops );
if (!dir)
return NULL;
list_init( &dir->change_q );
list_init( &dir->change_records );
dir->event = NULL;
dir->filter = 0;
dir->notified = 0;
dir->signaled = 0;
dir->want_data = 0;
dir->inode = NULL;
grab_object( fd );
dir->fd = fd;
set_fd_user( fd, &dir_fd_ops, &dir->obj );
dir_add_to_existing_notify( dir );
return &dir->obj;
}
/* enable change notifications for a directory */
DECL_HANDLER(read_directory_changes)
{
struct event *event = NULL;
struct dir *dir;
if (!req->filter)
{
set_error(STATUS_INVALID_PARAMETER);
return;
}
dir = get_dir_obj( current->process, req->handle, 0 );
if (!dir)
return;
/* possibly send changes through an event flag */
if (req->event)
{
event = get_event_obj( current->process, req->event, EVENT_MODIFY_STATE );
if (!event)
goto end;
}
/* discard the current data, and move onto the next event */
if (dir->event) release_object( dir->event );
dir->event = event;
/* requests don't timeout */
if ( req->io_apc && !create_async( current, NULL, &dir->change_q,
req->io_apc, req->io_user, req->io_sb ))
return;
/* assign it once */
if (!dir->filter)
{
init_inotify();
insert_change( dir );
dir->filter = req->filter;
dir->subtree = req->subtree;
dir->want_data = req->want_data;
}
/* remove any notifications */
if (dir->signaled>0)
dir->signaled--;
/* clear the event */
if (event)
reset_event( event );
/* if there's already a change in the queue, send it */
if (!list_empty( &dir->change_q ) &&
!list_empty( &dir->change_records ))
async_terminate_head( &dir->change_q, STATUS_ALERTED );
/* setup the real notification */
if (!inotify_adjust_changes( dir ))
dnotify_adjust_changes( dir );
set_error(STATUS_PENDING);
end:
release_object( dir );
}
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 );
/* now signal it */
dir->signaled++;
dir_signal_changed( dir );
release_object( dir );
}
Reference in New Issue View Git Blame Copy Permalink