The patch titled
logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutex
has been added to the -mm tree. Its filename is
logfs-fix-deadlock-in-logfs_get_wblocks-hold-and-wait-on-super-s_write_mutex.patch
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------------------------------------------------------
Subject: logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutex
From: Prasad Joshi <prasadjoshi124@xxxxxxxxx>
do_logfs_journal_wl_pass() should use GFP_NOFS for memory allocation GC
code calls btree_insert32 with GFP_KERNEL while holding a mutex
super->s_write_mutex. The same mutex is used in
address_space_operations->writepage(). Call to writepage() could be
triggered as a result of memory allocation in btree_insert32, causing a
deadlock.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20342
Signed-off-by: Prasad Joshi <prasadjoshi124@xxxxxxxxx>
Cc: Joern Engel <joern@xxxxxxxxx>
Cc: Florian Mickler <florian@xxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: Maciej Rutecki <maciej.rutecki@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/logfs/journal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN fs/logfs/journal.c~logfs-fix-deadlock-in-logfs_get_wblocks-hold-and-wait-on-super-s_write_mutex fs/logfs/journal.c
--- a/fs/logfs/journal.c~logfs-fix-deadlock-in-logfs_get_wblocks-hold-and-wait-on-super-s_write_mutex
+++ a/fs/logfs/journal.c
@@ -828,7 +828,7 @@ void do_logfs_journal_wl_pass(struct sup
super->s_journal_seg[i] = segno;
super->s_journal_ec[i] = ec;
logfs_set_segment_reserved(sb, segno);
- err = btree_insert32(head, segno, (void *)1, GFP_KERNEL);
+ err = btree_insert32(head, segno, (void *)1, GFP_NOFS);
BUG_ON(err); /* mempool should prevent this */
err = logfs_erase_segment(sb, segno, 1);
BUG_ON(err); /* FIXME: remount-ro would be nicer */
_
Patches currently in -mm which might be from prasadjoshi124@xxxxxxxxx are
logfs-fix-deadlock-in-logfs_get_wblocks-hold-and-wait-on-super-s_write_mutex.patch
logfs-fix-kernel-bug-at-readwritec-1193.patch
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