The patch titled
inotify: report rounded-up event size to user space
has been added to the -mm tree. Its filename is
inotify-reimplement-inotify-using-fsnotify-report-rounded-up-event-size-to-user-space.patch
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------------------------------------------------------
Subject: inotify: report rounded-up event size to user space
From: Wu Fengguang <fengguang.wu@xxxxxxxxx>
On Wed, May 06, 2009 at 09:42:58PM +0800, Kay Sievers wrote:
> On Mon, May 4, 2009 at 15:30, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote:
>
> > I tried remove every udev rules in /etc/udev/ and /lib/udev, the /etc/group
> > accesses disappeared in strace, but udevd is still busy.
>
> > ppoll([{fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=3, events=POLLIN}], 3, NULL, [], 8) = 1 ([{fd=3, revents=POLLIN}])
> > ioctl(3, FIONREAD, [39]) Â Â Â Â Â Â Â Â = 0
> > read(3, 0x62ad60, 39) Â Â Â Â Â Â Â Â Â = -1 EINVAL (Invalid argument)
>
> Seems, you have issues with inotify on your nfs mount?
>
> Inotify wakes up udevd to tell something in the rules directory has
> changed, but inotify seems not to return anything useful, but keeps
> waking us up. That causes an endless loop of parsing rules files.
Thanks for the tip. The failed inotify read() is caused by the size *roundup*
behavior introduced by the -mm commit 3b46cf7d5f3ca(Reimplement inotify_user
using fsnotify). Which says:
+ /*
+ * We need to pad the filename so as to properly align an
+ * array of inotify_event structures. Because the structure is
+ * small and the common case is a small filename, we just round
+ * up to the next multiple of the structure's sizeof. This is
+ * simple and safe for all architectures.
+ */
The udev madness originates from these kernel testing failures:
[ 756.569243] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.600103] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.630265] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.670862] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.701845] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.732899] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.763126] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.794829] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.824985] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 756.856760] get_one_event: event_size=48 > count=38, name_len=22, name=61-dev-root-link.rules
[ 761.608521] __ratelimit: 210 callbacks suppressed
Which are printed by the following patch:
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Acked-by: Eric Paris <eparis@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/notify/inotify/inotify_user.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN fs/notify/inotify/inotify_user.c~inotify-reimplement-inotify-using-fsnotify-report-rounded-up-event-size-to-user-space fs/notify/inotify/inotify_user.c
--- a/fs/notify/inotify/inotify_user.c~inotify-reimplement-inotify-using-fsnotify-report-rounded-up-event-size-to-user-space
+++ a/fs/notify/inotify/inotify_user.c
@@ -318,7 +318,9 @@ static long inotify_ioctl(struct file *f
mutex_lock(&group->notification_mutex);
list_for_each_entry(holder, &group->notification_list, event_list) {
event = holder->event;
- send_len += sizeof(struct inotify_event) + event->name_len;
+ send_len += sizeof(struct inotify_event);
+ send_len += roundup(event->name_len,
+ sizeof(struct inotify_event));
}
mutex_unlock(&group->notification_mutex);
ret = put_user(send_len, (int __user *) p);
_
Patches currently in -mm which might be from fengguang.wu@xxxxxxxxx are
origin.patch
linux-next.patch
readahead-make-mmap_miss-an-unsigned-int.patch
readahead-move-max_sane_readahead-calls-into-force_page_cache_readahead.patch
readahead-apply-max_sane_readahead-limit-in-ondemand_readahead.patch
readahead-remove-one-unnecessary-radix-tree-lookup.patch
readahead-increase-interleaved-readahead-size.patch
readahead-remove-sync-async-readahead-call-dependency.patch
readahead-clean-up-and-simplify-the-code-for-filemap-page-fault-readahead.patch
readahead-sequential-mmap-readahead.patch
readahead-enforce-full-readahead-size-on-async-mmap-readahead.patch
readahead-record-mmap-read-around-states-in-file_ra_state.patch
radix-tree-add-radix_tree_prev_hole.patch
readahead-move-the-random-read-case-to-bottom.patch
readahead-introduce-context-readahead-algorithm.patch
readahead-introduce-context-readahead-algorithm-update.patch
readahead-remove-redundant-test-in-shrink_readahead_size_eio.patch
readahead-enforce-full-sync-mmap-readahead-size.patch
pagemap-document-clarifications.patch
pagemap-documentation-9-more-exported-page-flags.patch
mm-introduce-pagehuge-for-testing-huge-gigantic-pages.patch
proc-kpagecount-kpageflags-code-cleanup.patch
proc-export-more-page-flags-in-proc-kpageflags.patch
vmscan-cleanup-the-scan-batching-code.patch
vmscan-dont-export-nr_saved_scan-in-proc-zoneinfo.patch
vmscan-zvc-updates-in-shrink_active_list-can-be-done-once.patch
inotify-reimplement-inotify-using-fsnotify-report-rounded-up-event-size-to-user-space.patch
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