Hey folks,
Looks like there's a regression with inotify since the rewrite to use
fanotify. Events are simply missing and not being delivered to
userspace.
Here's a simple test case, just compile and run it:
----8<--------8<--------8<--------8<--------8<--------8<--------8<----
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/inotify.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
enum {
WD = 0x01,
FOO = 0x02,
BAR = 0x04,
SUBDIR_WD = 0x08,
SUBDIR = 0x10,
SUBDIR_FOO = 0x20,
ALL = 0x3f
};
int
main (int argc,
char *argv[])
{
int fd;
char dirname[PATH_MAX];
char filename[PATH_MAX];
int ret;
FILE * fp;
int wd;
int subdir_wd;
char buf[4096];
int expected;
ssize_t len;
size_t sz;
fd = inotify_init ();
assert (fd >= 0);
/* Create a temporary directory with two files and a sub-directory
* containing just one file.
*/
strcpy (dirname, "/tmp/inotify_test_XXXXXX");
assert (mkdtemp (dirname));
strcpy (filename, dirname);
strcat (filename, "/subdir");
ret = mkdir (filename, 0755);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/subdir/foo");
fp = fopen (filename, "w");
assert (fp);
fprintf (fp, "file in a sub-directory\n");
ret = fclose (fp);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/foo");
fp = fopen (filename, "w");
assert (fp);
fprintf (fp, "this is a test\n");
ret = fclose (fp);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/bar");
fp = fopen (filename, "w");
assert (fp);
fprintf (fp, "this is another test\n");
ret = fclose (fp);
assert (ret == 0);
/* Watch those directories for deletions */
wd = inotify_add_watch (fd, dirname, IN_DELETE);
assert (wd >= 0);
strcpy (filename, dirname);
strcat (filename, "/subdir");
subdir_wd = inotify_add_watch (fd, filename, IN_DELETE);
assert (wd >= 0);
/* Clean up the directory */
strcpy (filename, dirname);
strcat (filename, "/subdir/foo");
ret = unlink (filename);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/subdir");
ret = rmdir (filename);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/bar");
ret = unlink (filename);
assert (ret == 0);
strcpy (filename, dirname);
strcat (filename, "/foo");
ret = unlink (filename);
assert (ret == 0);
ret = rmdir (dirname);
assert (ret == 0);
/* Read the inotify events */
expected = ALL;
while (expected) {
struct inotify_event *ev;
ssize_t off;
printf ("Waiting for:");
if (expected & WD)
printf (" wd");
if (expected & FOO)
printf (" foo");
if (expected & BAR)
printf (" bar");
if (expected & SUBDIR_WD)
printf (" subdir_wd");
if (expected & SUBDIR)
printf (" subdir");
if (expected & SUBDIR_FOO)
printf (" subdir/foo");
printf ("\n");
len = read (fd, buf, sizeof buf);
assert (len > 0);
off = 0;
while (off < len) {
ev = (struct inotify_event *)(buf + off);
sz = sizeof (struct inotify_event) + ev->len;
off += sz;
/* Eliminate the silly */
assert (! (ev->mask & IN_Q_OVERFLOW));
assert (! (ev->mask & IN_UNMOUNT));
/* Print the event for debugging */
printf ("Got ");
if (ev->mask & IN_DELETE)
printf ("DELETE ");
if (ev->mask & IN_IGNORED)
printf ("IGNORED ");
if (ev->mask & IN_ISDIR)
printf ("ISDIR ");
if (ev->len)
printf ("\"%.*s\" ", ev->len, ev->name);
printf ("(%d)\n", ev->wd);
/* Expect the file in the sub-directory to go */
if ((ev->wd == subdir_wd)
&& (ev->mask & IN_DELETE)
&& (! (ev->mask & IN_ISDIR))
&& (strncmp (ev->name, "foo", ev->len) == 0))
expected &= ~SUBDIR_FOO;
/* Expect the sub-directory to go */
if ((ev->wd == wd)
&& (ev->mask & IN_DELETE)
&& (ev->mask & IN_ISDIR)
&& (strncmp (ev->name, "subdir", ev->len) == 0))
expected &= ~SUBDIR;
/* Expect an IS_IGNORED for the sub-directory watch */
if ((ev->wd == subdir_wd)
&& (ev->mask & IN_IGNORED))
expected &= ~SUBDIR_WD;
/* Expect the first file in the directory to go */
if ((ev->wd == wd)
&& (ev->mask & IN_DELETE)
&& (! (ev->mask & IN_ISDIR))
&& (strncmp (ev->name, "foo", ev->len) == 0))
expected &= ~FOO;
/* Expect the second file in the directory to go */
if ((ev->wd == wd)
&& (ev->mask & IN_DELETE)
&& (! (ev->mask & IN_ISDIR))
&& (strncmp (ev->name, "bar", ev->len) == 0))
expected &= ~BAR;
/* And finally expect an IS_IGNORED for the directory */
if ((ev->wd == wd)
&& (ev->mask & IN_IGNORED))
expected &= ~WD;
}
}
ret = close (fd);
assert (ret == 0);
printf ("\n");
printf ("All good!\n");
return 0;
}
---->8-------->8-------->8-------->8-------->8-------->8-------->8----
With 2.6.30, you see (as you'd expect) an inotify delete event for each
of the files and the sub-directory along with the IN_IGNORED for the
sub-directory and directory as the watch gets cleaned up by the kernel:
Waiting for: wd foo bar subdir_wd subdir subdir/foo
Got DELETE "foo" (2)
Got DELETE ISDIR "subdir" (1)
Got IGNORED (2)
Got DELETE "bar" (1)
Got DELETE "foo" (1)
Got IGNORED (1)
All good!
But with 2.6.31-rc2, the event for the "foo" file isn't delivered:
Waiting for: wd foo bar subdir_wd subdir subdir/foo
Got DELETE "foo" (2)
Got DELETE ISDIR "subdir" (1)
Got IGNORED (2)
Got DELETE "bar" (1)
Got IGNORED (1)
Waiting for: foo
This doesn't seem to be related to the removal of the parent directory,
without removing that we still hang waiting for the event for that file.
Scott
--
Scott James Remnant
[email protected]
On Sat, 2009-07-11 at 17:02 +0100, Scott James Remnant wrote:
> Hey folks,
>
> Looks like there's a regression with inotify since the rewrite to use
> fanotify. Events are simply missing and not being delivered to
> userspace.
>
> Here's a simple test case, just compile and run it:
I bet I know exactly what it is (notification.c tail merge code isn't
comparing filename only inode+mask) but I'm walking out of the house.
I'll try my theory later tonight and post a patch.
Stupid Eric, Stupid.
-Eric
On Sat, 2009-07-11 at 07:50 -0400, Eric Paris wrote:
> On Sat, 2009-07-11 at 17:02 +0100, Scott James Remnant wrote:
> > Looks like there's a regression with inotify since the rewrite to use
> > fanotify. Events are simply missing and not being delivered to
> > userspace.
> >
> > Here's a simple test case, just compile and run it:
>
> I bet I know exactly what it is (notification.c tail merge code isn't
> comparing filename only inode+mask) but I'm walking out of the house.
> I'll try my theory later tonight and post a patch.
>
> Stupid Eric, Stupid.
>
In other words, when the second deleted-file-in-a-directory event comes
through, it gets ignored because there's already a
"deleted-file-in-a-directory" event for that directory?
Scott
--
Scott James Remnant
[email protected]
On Mon, 2009-07-13 at 13:21 +0100, Scott James Remnant wrote:
> On Sat, 2009-07-11 at 07:50 -0400, Eric Paris wrote:
>
> > On Sat, 2009-07-11 at 17:02 +0100, Scott James Remnant wrote:
> > > Looks like there's a regression with inotify since the rewrite to use
> > > fanotify. Events are simply missing and not being delivered to
> > > userspace.
> > >
> > > Here's a simple test case, just compile and run it:
> >
> > I bet I know exactly what it is (notification.c tail merge code isn't
> > comparing filename only inode+mask) but I'm walking out of the house.
> > I'll try my theory later tonight and post a patch.
> >
> > Stupid Eric, Stupid.
> >
> In other words, when the second deleted-file-in-a-directory event comes
> through, it gets ignored because there's already a
> "deleted-file-in-a-directory" event for that directory?
Yes, and I sent a patch but apparent screwed up the --smtp-server option
so it never got out. Resending. Sorry.....
-Eric
On Monday 13 July 2009, Eric Paris wrote:
> On Mon, 2009-07-13 at 13:21 +0100, Scott James Remnant wrote:
> > On Sat, 2009-07-11 at 07:50 -0400, Eric Paris wrote:
> >
> > > On Sat, 2009-07-11 at 17:02 +0100, Scott James Remnant wrote:
> > > > Looks like there's a regression with inotify since the rewrite to use
> > > > fanotify. Events are simply missing and not being delivered to
> > > > userspace.
> > > >
> > > > Here's a simple test case, just compile and run it:
> > >
> > > I bet I know exactly what it is (notification.c tail merge code isn't
> > > comparing filename only inode+mask) but I'm walking out of the house.
> > > I'll try my theory later tonight and post a patch.
> > >
> > > Stupid Eric, Stupid.
> > >
> > In other words, when the second deleted-file-in-a-directory event comes
> > through, it gets ignored because there's already a
> > "deleted-file-in-a-directory" event for that directory?
>
> Yes, and I sent a patch but apparent screwed up the --smtp-server option
> so it never got out. Resending. Sorry.....
Did the patch reach Linus eventually?
Rafael
On Sun, 2009-07-26 at 00:23 +0200, Rafael J. Wysocki wrote:
> On Monday 13 July 2009, Eric Paris wrote:
> > On Mon, 2009-07-13 at 13:21 +0100, Scott James Remnant wrote:
> > > On Sat, 2009-07-11 at 07:50 -0400, Eric Paris wrote:
> > >
> > > > On Sat, 2009-07-11 at 17:02 +0100, Scott James Remnant wrote:
> > > > > Looks like there's a regression with inotify since the rewrite to use
> > > > > fanotify. Events are simply missing and not being delivered to
> > > > > userspace.
> > > > >
> > > > > Here's a simple test case, just compile and run it:
> > > >
> > > > I bet I know exactly what it is (notification.c tail merge code isn't
> > > > comparing filename only inode+mask) but I'm walking out of the house.
> > > > I'll try my theory later tonight and post a patch.
> > > >
> > > > Stupid Eric, Stupid.
> > > >
> > > In other words, when the second deleted-file-in-a-directory event comes
> > > through, it gets ignored because there's already a
> > > "deleted-file-in-a-directory" event for that directory?
> >
> > Yes, and I sent a patch but apparent screwed up the --smtp-server option
> > so it never got out. Resending. Sorry.....
>
> Did the patch reach Linus eventually?
No, I sent a git-pull but Linus did not pull from my tree before -rc4.
If he doesn't do it in his openning -rc5 salvo I'll send the request
again.
-Eric