From: Ye Bin yebin10@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LHTR CVE: NA
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When do BULKSTAT test got issues as follows: WARNING: CPU: 3 PID: 8425 at fs/xfs/xfs_aops.c:509 xfs_vm_writepages+0x184/0x1c0 Modules linked in: CPU: 3 PID: 8425 Comm: xfs_bulkstat Not tainted 6.3.0-next-20230505-00003-gf3329adf5424-dirty #456 RIP: 0010:xfs_vm_writepages+0x184/0x1c0 RSP: 0018:ffffc90014bb7088 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff92002976e11 RCX: ffff88817aef8000 RDX: 0000000000000000 RSI: ffff88817aef8000 RDI: 0000000000000002 RBP: ffff888267dd2ad8 R08: ffffffff8313f414 R09: ffffed1022377c18 R10: ffff888111bbe0bb R11: ffffed1022377c17 R12: ffff88817aef8000 R13: ffffc90014bb7358 R14: dffffc0000000000 R15: ffffffff8313f290 FS: 00007f9568bb0440(0000) GS:ffff88882fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000d7a008 CR3: 000000024e11f000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> do_writepages+0x1a8/0x630 __writeback_single_inode+0x126/0xe00 writeback_single_inode+0x2ae/0x530 write_inode_now+0x16e/0x1e0 iput.part.0+0x46c/0x730 iput+0x60/0x80 xfs_bulkstat_one_int+0xd87/0x1580 xfs_bulkstat_iwalk+0x6e/0xd0 xfs_iwalk_ag_recs+0x449/0x770 xfs_iwalk_run_callbacks+0x305/0x630 xfs_iwalk_ag+0x819/0xae0 xfs_iwalk+0x2d5/0x4e0 xfs_bulkstat+0x358/0x520 xfs_ioc_bulkstat.isra.0+0x242/0x340 xfs_file_ioctl+0x1d6/0x1ba0 __x64_sys_ioctl+0x197/0x210 do_syscall_64+0x39/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Above issue may happens as follows: Porcess1 Process2 process3 process4 xfs_bulkstat xfs_trans_alloc_empty xfs_bulkstat_one_int xfs_iget(XFS_IGET_DONTCACHE) ->Get inode from disk and mark inode with I_DONTCACHE
xfs_lookup xfs_iget ->Hold inode refcount xfs_irele
xfs_file_write_iter ->Write file made some dirty pages close file
xfs_bulkstat xfs_trans_alloc_empty xfs_bulkstat_one_int xfs_iget(XFS_IGET_DONTCACHE)
-> process4 close file
******Trigger dentry reclaim, inode refcount is 1****** xfs_irele iput ->Put the last refcount iput_final write_inode_now xfs_vm_writepages WARN_ON_ONCE(current->journal_info) ->Trigger warning
As commit a6343e4d9278 grab an empty transaction when do BULKSTAT. If put the last refcount of inode maybe cause writepages will trigger warning, and also lead to data loss. To solve above issue if xfs_iget_cache_hit() just clear inode's I_DONTCACHE flags.
Fixes: a6343e4d9278 ("xfs: avoid buffer deadlocks when walking fs inodes") Signed-off-by: Ye Bin yebin10@huawei.com Signed-off-by: Long Li leo.lilong@huawei.com --- fs/xfs/xfs_icache.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 3c210ac83713..f4971bd1de05 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -557,6 +557,12 @@ xfs_iget_cache_hit( if (!igrab(inode)) goto out_skip;
+ if (!(flags & XFS_IGET_DONTCACHE)) { + spin_lock(&inode->i_lock); + inode->i_state &= ~I_DONTCACHE; + spin_unlock(&inode->i_lock); + } + /* We've got a live one. */ spin_unlock(&ip->i_flags_lock); rcu_read_unlock();