The patch titled
make inotify event handles use GFP_NOFS
has been added to the -mm tree. Its filename is
inotify-use-gfp_nofs-in-kernel_event-to-work-around-a-lockdep-false-positive-fix.patch
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------------------------------------------------------
Subject: make inotify event handles use GFP_NOFS
From: Eric Paris <eparis@xxxxxxxxxx>
I think this is a bandaide to shut up lockdep. I could either figure out
lockdep classes and figure out how to reclassify inotify locks since I
believe Nick is correct when he says inotify watches pin the inode in core
so memory pressure can't evict it. I don't want to do that as I think the
real fix is my next generation fsnotify which does zero allocations under
locks and so everything can be GFP_KERNEL. I'm posting this as it is
clearly safe and should fix the issue.
http://marc.info/?l=linux-kernel&m=123617147432377&w=2
includes a lockdep warning that shows while we are reclaiming FS memory
and inode may get evicted which generates an IN_IGNORED message. Half
of that code path already used GFP_NOFS but a second allocation to store
the filename was using GFP_KERNEL. As a precaution I also moved the
audit handle_event code path to use GFP_NOFS.
This is much the same as the precaution in f04b30de3c82528 which did
something similar.
Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Christoph Lameter <clameter@xxxxxxx>
Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/auditfilter.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN kernel/auditfilter.c~inotify-use-gfp_nofs-in-kernel_event-to-work-around-a-lockdep-false-positive-fix kernel/auditfilter.c
--- a/kernel/auditfilter.c~inotify-use-gfp_nofs-in-kernel_event-to-work-around-a-lockdep-false-positive-fix
+++ a/kernel/auditfilter.c
@@ -1028,7 +1028,7 @@ static void audit_update_watch(struct au
if (audit_enabled) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_KERNEL,
+ ab = audit_log_start(NULL, GFP_NOFS,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, "auid=%u ses=%u",
audit_get_loginuid(current),
@@ -1067,7 +1067,7 @@ static void audit_remove_parent_watches(
e = container_of(r, struct audit_entry, rule);
if (audit_enabled) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_KERNEL,
+ ab = audit_log_start(NULL, GFP_NOFS,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, "auid=%u ses=%u",
audit_get_loginuid(current),
_
Patches currently in -mm which might be from eparis@xxxxxxxxxx are
inotify-use-gfp_nofs-in-kernel_event-to-work-around-a-lockdep-false-positive.patch
inotify-use-gfp_nofs-in-kernel_event-to-work-around-a-lockdep-false-positive-fix.patch
linux-next.patch
fsnotify-unified-filesystem-notification-backend.patch
fsnotify-add-marks-to-inodes-so-groups-can-interpret-how-to-handle-those-inodes.patch
fsnotify-parent-event-notification.patch
dnotify-reimplement-dnotify-using-fsnotify.patch
fsnotify-generic-notification-queue-and-waitq.patch
fsnotify-include-pathnames-with-entries-when-possible.patch
fsnotify-add-correlations-between-events.patch
fsnotify-allow-groups-to-add-private-data-to-events.patch
fsnotify-fsnotify-marks-on-inodes-pin-them-in-core.patch
fsnotify-handle-filesystem-unmounts-with-fsnotify-marks.patch
inotify-reimplement-inotify-using-fsnotify.patch
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