/* * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA */ #include "config.h" #include "wine/port.h" #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_SYS_ERRNO_H #include #endif #include "ntstatus.h" #define WIN32_NO_STATUS #include "windef.h" #include "file.h" #include "handle.h" #include "thread.h" #include "request.h" #include "process.h" #include "security.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 attributes */ #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */ #endif #endif /* inotify support */ #ifdef HAVE_SYS_INOTIFY_H #include #define USE_INOTIFY #elif 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_rm_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 */ mode_t mode; /* file stat.st_mode */ uid_t uid; /* file stat.st_uid */ struct list entry; /* entry in global change notifications list */ unsigned int filter; /* notification filter */ int notified; /* SIGIO counter */ int want_data; /* return change data */ int subtree; /* do we want to watch subdirectories? */ 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 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 ); static void dir_dump( struct object *obj, int verbose ); static void dir_destroy( struct object *obj ); static const struct object_ops dir_ops = { sizeof(struct dir), /* size */ dir_dump, /* dump */ no_get_type, /* get_type */ add_queue, /* add_queue */ remove_queue, /* remove_queue */ default_fd_signaled, /* signaled */ no_satisfied, /* satisfied */ no_signal, /* signal */ dir_get_fd, /* get_fd */ default_fd_map_access, /* map_access */ dir_get_sd, /* get_sd */ dir_set_sd, /* set_sd */ no_lookup_name, /* lookup_name */ no_open_file, /* open_file */ fd_close_handle, /* close_handle */ dir_destroy /* destroy */ }; static int dir_get_poll_events( struct fd *fd ); static enum server_fd_type dir_get_fd_type( 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_fd_type, /* get_fd_type */ default_fd_ioctl, /* ioctl */ default_fd_queue_async, /* queue_async */ default_fd_reselect_async, /* reselect_async */ default_fd_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 filter=%08x\n", dir->fd, dir->filter ); } /* 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; } } /* 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 ) { if (interlocked_xchg( &dir->notified, 0 )) fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_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 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; struct stat st; mode_t mode; int unix_fd; assert( obj->ops == &dir_ops ); unix_fd = get_dir_unix_fd( dir ); if (unix_fd == -1 || fstat( unix_fd, &st ) == -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 = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG); mode |= sd_to_mode( sd, owner ); if (st.st_mode != mode && fchmod( unix_fd, mode ) == -1) { file_set_error(); return 0; } } return 1; } 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 ); } while ((record = get_first_change_record( dir ))) free( record ); release_object( dir->fd ); if (inotify_fd && list_empty( &change_list )) { release_object( inotify_fd ); inotify_fd = NULL; } } 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 enum server_fd_type dir_get_fd_type( struct fd *fd ) { return FD_TYPE_DIR; } #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 ) { free (inode->name); inode->name = name ? strdup( name ) : NULL; } static void free_inode( struct inode *inode ) { int subtree = 0, watches = 0; struct inode *tmp, *next; struct dir *dir; LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry ) { subtree |= dir->subtree; watches++; } if (!subtree && !inode->parent) { 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 ); /* 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; } if (inode->wd != -1) { inotify_rm_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 const struct fd_ops inotify_fd_ops = { inotify_get_poll_events, /* get_poll_events */ inotify_poll_event, /* poll_event */ NULL, /* flush */ NULL, /* get_fd_type */ NULL, /* ioctl */ NULL, /* queue_async */ NULL, /* reselect_async */ NULL, /* 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 ); } fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, 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 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, 0 ); } 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; ifd ); 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, unsigned int access, mode_t mode ) { 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; dir->mode = mode; dir->uid = ~(uid_t)0; 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 dir *dir; struct async *async; if (!req->filter) { set_error(STATUS_INVALID_PARAMETER); return; } dir = get_dir_obj( current->process, req->async.handle, 0 ); if (!dir) return; /* requests don't timeout */ if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end; /* 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; } /* if there's already a change in the queue, send it */ if (!list_empty( &dir->change_records )) fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED ); /* setup the real notification */ if (!inotify_adjust_changes( dir )) dnotify_adjust_changes( dir ); release_object( async ); 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 ); release_object( dir ); }