From: Chandan Babu R <chandanrlinux@gmail.com>
To: linux-xfs@vger.kernel.org
Cc: Chandan Babu R <chandanrlinux@gmail.com>, djwong@kernel.org
Subject: [PATCH 1/2] xfs: Initialize xfs_alloc_arg->total correctly when allocating minlen extents
Date: Thu, 25 Mar 2021 19:33:38 +0530 [thread overview]
Message-ID: <20210325140339.6603-1-chandanrlinux@gmail.com> (raw)
xfs/538 can cause the following call trace to be printed when executing on a
multi-block directory configuration,
WARNING: CPU: 1 PID: 2578 at fs/xfs/libxfs/xfs_bmap.c:717 xfs_bmap_extents_to_btree+0x520/0x5d0
Call Trace:
? xfs_buf_rele+0x4f/0x450
xfs_bmap_add_extent_hole_real+0x747/0x960
xfs_bmapi_allocate+0x39a/0x440
xfs_bmapi_write+0x507/0x9e0
xfs_da_grow_inode_int+0x1cd/0x330
? up+0x12/0x60
xfs_dir2_grow_inode+0x62/0x110
? xfs_trans_log_inode+0x234/0x2d0
xfs_dir2_sf_to_block+0x103/0x940
? xfs_dir2_sf_check+0x8c/0x210
? xfs_da_compname+0x19/0x30
? xfs_dir2_sf_lookup+0xd0/0x3d0
xfs_dir2_sf_addname+0x10d/0x910
xfs_dir_createname+0x1ad/0x210
xfs_create+0x404/0x620
xfs_generic_create+0x24c/0x320
path_openat+0xda6/0x1030
do_filp_open+0x88/0x130
? kmem_cache_alloc+0x50/0x210
? __cond_resched+0x16/0x40
? kmem_cache_alloc+0x50/0x210
do_sys_openat2+0x97/0x150
__x64_sys_creat+0x49/0x70
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
This occurs because xfs_bmap_exact_minlen_extent_alloc() initializes
xfs_alloc_arg->total to xfs_bmalloca->minlen. In the context of
xfs_bmap_exact_minlen_extent_alloc(), xfs_bmalloca->minlen has a value of 1
and hence the space allocator could choose an AG which has less than
xfs_bmalloca->total number of free blocks available. As the transaction
proceeds, one of the future space allocation requests could fail due to
non-availability of free blocks in the AG that was originally chosen.
This commit fixes the bug by assigning xfs_alloc_arg->total to the value of
xfs_bmalloca->total.
Fixes: 301519674699 ("xfs: Introduce error injection to allocate only minlen size extents for files")
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
fs/xfs/libxfs/xfs_bmap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index e0905ad171f0..585f7e795023 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3586,7 +3586,8 @@ xfs_bmap_exact_minlen_extent_alloc(
args.fsbno = ap->blkno;
args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
args.type = XFS_ALLOCTYPE_FIRST_AG;
- args.total = args.minlen = args.maxlen = ap->minlen;
+ args.minlen = args.maxlen = ap->minlen;
+ args.total = ap->total;
args.alignment = 1;
args.minalignslop = 0;
--
2.29.2
next reply other threads:[~2021-03-25 14:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-25 14:03 Chandan Babu R [this message]
2021-03-25 14:03 ` [PATCH 2/2] xfs: Fix dax inode extent calculation when direct write is performed on an unwritten extent Chandan Babu R
2021-03-25 18:53 ` Darrick J. Wong
2021-04-02 6:45 ` Christoph Hellwig
2021-03-25 18:54 ` [PATCH 1/2] xfs: Initialize xfs_alloc_arg->total correctly when allocating minlen extents Darrick J. Wong
2021-04-02 6:44 ` Christoph Hellwig
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