This is a note to let you know that I've just added the patch titled
ocfs2: ac->ac_allow_chain_relink=0 won't disable group relink
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ocfs2-ac-ac_allow_chain_relink-0-won-t-disable-group-relink.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 309a85b6861fedbb48a22d45e0e079d1be993b3a Mon Sep 17 00:00:00 2001
From: "Xiaowei.Hu" <xiaowei.hu@xxxxxxxxxx>
Date: Wed, 27 Feb 2013 17:02:49 -0800
Subject: ocfs2: ac->ac_allow_chain_relink=0 won't disable group relink
From: "Xiaowei.Hu" <xiaowei.hu@xxxxxxxxxx>
commit 309a85b6861fedbb48a22d45e0e079d1be993b3a upstream.
ocfs2_block_group_alloc_discontig() disables chain relink by setting
ac->ac_allow_chain_relink = 0 because it grabs clusters from multiple
cluster groups.
It doesn't keep the credits for all chain relink,but
ocfs2_claim_suballoc_bits overrides this in this call trace:
ocfs2_block_group_claim_bits()->ocfs2_claim_clusters()->
__ocfs2_claim_clusters()->ocfs2_claim_suballoc_bits()
ocfs2_claim_suballoc_bits set ac->ac_allow_chain_relink = 1; then call
ocfs2_search_chain() one time and disable it again, and then we run out
of credits.
Fix is to allow relink by default and disable it in
ocfs2_block_group_alloc_discontig.
Without this patch, End-users will run into a crash due to run out of
credits, backtrace like this:
RIP: 0010:[<ffffffffa0808b14>] [<ffffffffa0808b14>]
jbd2_journal_dirty_metadata+0x164/0x170 [jbd2]
RSP: 0018:ffff8801b919b5b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88022139ddc0 RCX: ffff880159f652d0
RDX: ffff880178aa3000 RSI: ffff880159f652d0 RDI: ffff880087f09bf8
RBP: ffff8801b919b5e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001e00 R11: 00000000000150b0 R12: ffff880159f652d0
R13: ffff8801a0cae908 R14: ffff880087f09bf8 R15: ffff88018d177800
FS: 00007fc9b0b6b6e0(0000) GS:ffff88022fd40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 000000000040819c CR3: 0000000184017000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process dd (pid: 9945, threadinfo ffff8801b919a000, task ffff880149a264c0)
Call Trace:
ocfs2_journal_dirty+0x2f/0x70 [ocfs2]
ocfs2_relink_block_group+0x111/0x480 [ocfs2]
ocfs2_search_chain+0x455/0x9a0 [ocfs2]
...
Signed-off-by: Xiaowei.Hu <xiaowei.hu@xxxxxxxxxx>
Reviewed-by: Srinivas Eeda <srinivas.eeda@xxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/suballoc.c | 7 +++----
fs/ocfs2/suballoc.h | 2 +-
2 files changed, 4 insertions(+), 5 deletions(-)
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -642,7 +642,7 @@ ocfs2_block_group_alloc_discontig(handle
* cluster groups will be staying in cache for the duration of
* this operation.
*/
- ac->ac_allow_chain_relink = 0;
+ ac->ac_disable_chain_relink = 1;
/* Claim the first region */
status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
@@ -1823,7 +1823,7 @@ static int ocfs2_search_chain(struct ocf
* Do this *after* figuring out how many bits we're taking out
* of our target group.
*/
- if (ac->ac_allow_chain_relink &&
+ if (!ac->ac_disable_chain_relink &&
(prev_group_bh) &&
(ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
status = ocfs2_relink_block_group(handle, alloc_inode,
@@ -1928,7 +1928,6 @@ static int ocfs2_claim_suballoc_bits(str
victim = ocfs2_find_victim_chain(cl);
ac->ac_chain = victim;
- ac->ac_allow_chain_relink = 1;
status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
res, &bits_left);
@@ -1947,7 +1946,7 @@ static int ocfs2_claim_suballoc_bits(str
* searching each chain in order. Don't allow chain relinking
* because we only calculate enough journal credits for one
* relink per alloc. */
- ac->ac_allow_chain_relink = 0;
+ ac->ac_disable_chain_relink = 1;
for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
if (i == victim)
continue;
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -49,7 +49,7 @@ struct ocfs2_alloc_context {
/* these are used by the chain search */
u16 ac_chain;
- int ac_allow_chain_relink;
+ int ac_disable_chain_relink;
group_search_t *ac_group_search;
u64 ac_last_group;
Patches currently in stable-queue which might be from xiaowei.hu@xxxxxxxxxx are
queue-3.0/ocfs2-ac-ac_allow_chain_relink-0-won-t-disable-group-relink.patch
--
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