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.
Signed-off-by: Prasad Joshi <[email protected]>
---
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c
index f46ee8b..9da2970 100644
--- a/fs/logfs/journal.c
+++ b/fs/logfs/journal.c
@@ -828,7 +828,7 @@ void do_logfs_journal_wl_pass(struct super_block *sb)
???? ??? 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 */
---------- Forwarded message ----------
From: <[email protected]>
Date: Tue, Nov 16, 2010 at 3:28 PM
Subject: [Bug 20342] [LogFS] [2.6.36-rc7] Deadlock in
logfs_get_wblocks, hold and wait on same lock super->s_write_mutex
To: [email protected]
https://bugzilla.kernel.org/show_bug.cgi?id=20342
Florian Mickler <[email protected]> changed:
? ? ? ? ? What ? ?|Removed ? ? ? ? ? ? ? ? ? ? |Added
----------------------------------------------------------------------------
? ? ? ? ? ? ? ? CC| ? ? ? ? ? ? ? ? ? ? ? ? ? ?|[email protected]
--- Comment #2 from Florian Mickler <[email protected]> ?2010-11-16
15:27:59 ---
Please submit this patch on lkml and the logfs mailinglist for review. The
logfs maintainers seem to not be aware of the bugzilla.
( Documentation/SubmittingPatches )
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