The following commit has been merged in the linux branch: commit 945526846a84c00adac1efd1c6befdaa77039623 Author: Andreas Gruenbacher agruen@suse.de Date: Thu Oct 15 00:13:23 2009 +0200

dnotify: ignore FS_EVENT_ON_CHILD

Mask off FS_EVENT_ON_CHILD in dnotify_handle_event(). Otherwise, when there is more than one watch on a directory and dnotify_should_send_event() succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause spurious events.

This case was overlooked in commit e42e2773.

#define _GNU_SOURCE

#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <signal.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h>

static void create_event(int s, siginfo_t* si, void* p) { printf("create\n"); }

static void delete_event(int s, siginfo_t* si, void* p) { printf("delete\n"); }

int main (void) { struct sigaction action; char *tmpdir, *file; int fd1, fd2;

sigemptyset (&action.sa_mask); action.sa_flags = SA_SIGINFO;

action.sa_sigaction = create_event; sigaction (SIGRTMIN + 0, &action, NULL);

action.sa_sigaction = delete_event; sigaction (SIGRTMIN + 1, &action, NULL);

# define TMPDIR "/tmp/test.XXXXXX" tmpdir = malloc(strlen(TMPDIR) + 1); strcpy(tmpdir, TMPDIR); mkdtemp(tmpdir);

# define TMPFILE "/file" file = malloc(strlen(tmpdir) + strlen(TMPFILE) + 1); sprintf(file, "%s/%s", tmpdir, TMPFILE);

fd1 = open (tmpdir, O_RDONLY); fcntl(fd1, F_SETSIG, SIGRTMIN); fcntl(fd1, F_NOTIFY, DN_MULTISHOT | DN_CREATE);

fd2 = open (tmpdir, O_RDONLY); fcntl(fd2, F_SETSIG, SIGRTMIN + 1); fcntl(fd2, F_NOTIFY, DN_MULTISHOT | DN_DELETE);

if (fork()) { /* This triggers a create event */ creat(file, 0600); /* This triggers a create and delete event (!) */ unlink(file); } else { sleep(1); rmdir(tmpdir); }

return 0; }

Signed-off-by: Andreas Gruenbacher agruen@suse.de Signed-off-by: Eric Paris eparis@redhat.com

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index 828a889..7e54e52 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -91,6 +91,7 @@ static int dnotify_handle_event(struct fsnotify_group *group, struct dnotify_struct *dn; struct dnotify_struct **prev; struct fown_struct *fown; + __u32 test_mask = event->mask & ~FS_EVENT_ON_CHILD;

to_tell = event->to_tell;

@@ -106,7 +107,7 @@ static int dnotify_handle_event(struct fsnotify_group *group, spin_lock(&entry->lock); prev = &dnentry->dn; while ((dn = *prev) != NULL) { - if ((dn->dn_mask & event->mask) == 0) { + if ((dn->dn_mask & test_mask) == 0) { prev = &dn->dn_next; continue; }