From 294fc7a4c8ec42b3053b1d2e87b0dafef80a76b8 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Thu, 1 Aug 2019 13:47:07 -0700
Subject: [PATCH] fs: xfs: xfs_log: Don't use KM_MAYFAIL at xfs_log_reserve().
Git-commit: 294fc7a4c8ec42b3053b1d2e87b0dafef80a76b8
Patch-mainline: v5.3-rc5
References: bsc#1148033
When the system is close-to-OOM, fsync() may fail due to -ENOMEM because
xfs_log_reserve() is using KM_MAYFAIL. It is a bad thing to fail writeback
operation due to user-triggerable OOM condition. Since we are not using
KM_MAYFAIL at xfs_trans_alloc() before calling xfs_log_reserve(), let's
use the same flags at xfs_log_reserve().
oom-torture: page allocation failure: order:0, mode:0x46c40(GFP_NOFS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), nodemask=(null)
CPU: 7 PID: 1662 Comm: oom-torture Kdump: loaded Not tainted 5.3.0-rc2+ #925
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00
Call Trace:
dump_stack+0x67/0x95
warn_alloc+0xa9/0x140
__alloc_pages_slowpath+0x9a8/0xbce
__alloc_pages_nodemask+0x372/0x3b0
alloc_slab_page+0x3a/0x8d0
new_slab+0x330/0x420
___slab_alloc.constprop.94+0x879/0xb00
__slab_alloc.isra.89.constprop.93+0x43/0x6f
kmem_cache_alloc+0x331/0x390
kmem_zone_alloc+0x9f/0x110 [xfs]
kmem_zone_alloc+0x9f/0x110 [xfs]
xlog_ticket_alloc+0x33/0xd0 [xfs]
xfs_log_reserve+0xb4/0x410 [xfs]
xfs_trans_reserve+0x1d1/0x2b0 [xfs]
xfs_trans_alloc+0xc9/0x250 [xfs]
xfs_setfilesize_trans_alloc.isra.27+0x44/0xc0 [xfs]
xfs_submit_ioend.isra.28+0xa5/0x180 [xfs]
xfs_vm_writepages+0x76/0xa0 [xfs]
do_writepages+0x17/0x80
__filemap_fdatawrite_range+0xc1/0xf0
file_write_and_wait_range+0x53/0xa0
xfs_file_fsync+0x87/0x290 [xfs]
vfs_fsync_range+0x37/0x80
do_fsync+0x38/0x60
__x64_sys_fsync+0xf/0x20
do_syscall_64+0x4a/0x1c0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fixes: eb01c9cd87 ("[XFS] Remove the xlog_ticket allocator")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Anthony Iliopoulos <ailiopoulos@suse.com>
---
fs/xfs/xfs_log.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 00e9f5c388d3..7fc3c1ad36bc 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -429,10 +429,7 @@ xfs_log_reserve(
ASSERT(*ticp == NULL);
tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
- KM_SLEEP | KM_MAYFAIL);
- if (!tic)
- return -ENOMEM;
-
+ KM_SLEEP);
*ticp = tic;
xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
--
2.16.4