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| author | Chao Yu <chao2.yu@samsung.com> | 2016-02-26 04:33:04 +0300 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2016-02-26 22:52:03 +0300 |
| commit | 19c7377b56a618c2a6ae1dfef1c22f19ad9d427c (patch) | |
| tree | 401ffa888a214a430e2b39e7eba259014d5dca5b /fs/f2fs/node.c | |
| parent | 406657dd1868a4d7b12be04ed769d9215ec9a7d1 (diff) | |
| download | linux-19c7377b56a618c2a6ae1dfef1c22f19ad9d427c.tar.xz | |
f2fs: fix to avoid deadlock when merging inline data
When testing with fsstress, kworker and user threads were both blocked:
INFO: task kworker/u16:1:16580 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u16:1 D ffff8803f2595390 0 16580 2 0x00000000
Workqueue: writeback bdi_writeback_workfn (flush-251:0)
ffff8802730e5760 0000000000000046 ffff880274729fc0 0000000000012440
ffff8802730e5fd8 ffff8802730e4010 0000000000012440 0000000000012440
ffff8802730e5fd8 0000000000012440 ffff880274729fc0 ffff88026eb50000
Call Trace:
[<ffffffff816fe9d9>] schedule+0x29/0x70
[<ffffffff816ff895>] rwsem_down_read_failed+0xa5/0xf9
[<ffffffff81378584>] call_rwsem_down_read_failed+0x14/0x30
[<ffffffffa0694feb>] f2fs_write_data_page+0x31b/0x420 [f2fs]
[<ffffffffa0690f1a>] __f2fs_writepage+0x1a/0x50 [f2fs]
[<ffffffffa06922a0>] f2fs_write_data_pages+0xe0/0x290 [f2fs]
[<ffffffff811473b3>] do_writepages+0x23/0x40
[<ffffffff811cc3ee>] __writeback_single_inode+0x4e/0x250
[<ffffffff811cd4f1>] writeback_sb_inodes+0x2c1/0x470
[<ffffffff811cd73e>] __writeback_inodes_wb+0x9e/0xd0
[<ffffffff811cda0b>] wb_writeback+0x1fb/0x2d0
[<ffffffff811cdb7c>] wb_do_writeback+0x9c/0x220
[<ffffffff811ce232>] bdi_writeback_workfn+0x72/0x1c0
[<ffffffff8106b74e>] process_one_work+0x1de/0x5b0
[<ffffffff8106e78f>] worker_thread+0x11f/0x3e0
[<ffffffff810750ce>] kthread+0xde/0xf0
[<ffffffff817093f8>] ret_from_fork+0x58/0x90
fsstress thread stack:
[<ffffffff81139f0e>] sleep_on_page+0xe/0x20
[<ffffffff81139ef7>] __lock_page+0x67/0x70
[<ffffffff8113b100>] find_lock_page+0x50/0x80
[<ffffffff8113b24f>] find_or_create_page+0x3f/0xb0
[<ffffffffa06983a9>] sync_node_pages+0x259/0x810 [f2fs]
[<ffffffffa068d874>] write_checkpoint+0x1a4/0xce0 [f2fs]
[<ffffffffa0686b0c>] f2fs_sync_fs+0x7c/0xd0 [f2fs]
[<ffffffffa067c813>] f2fs_sync_file+0x143/0x5f0 [f2fs]
[<ffffffff811d301b>] vfs_fsync_range+0x2b/0x40
[<ffffffff811d304c>] vfs_fsync+0x1c/0x20
[<ffffffff811d3291>] do_fsync+0x41/0x70
[<ffffffff811d32d3>] SyS_fdatasync+0x13/0x20
[<ffffffff817094a2>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
The reason of this issue is:
CPU0: CPU1:
- f2fs_write_data_pages
- f2fs_sync_fs
- write_checkpoint
- block_operations
- f2fs_lock_all
- down_write(sbi->cp_rwsem)
- lock_page(page)
- f2fs_write_data_page
- sync_node_pages
- flush_inline_data
- pagecache_get_page(page, GFP_LOCK)
- f2fs_lock_op
- down_read(sbi->cp_rwsem)
This patch alters to use trylock_page in flush_inline_data to fix this ABBA
deadlock issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/node.c')
| -rw-r--r-- | fs/f2fs/node.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 7b613dd16e77..d714b607bf46 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1203,10 +1203,13 @@ static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino) if (!inode) return; - page = pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0); + page = pagecache_get_page(inode->i_mapping, 0, FGP_NOWAIT, 0); if (!page) goto iput_out; + if (!trylock_page(page)) + goto release_out; + if (!PageUptodate(page)) goto page_out; @@ -1221,7 +1224,9 @@ static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino) else set_page_dirty(page); page_out: - f2fs_put_page(page, 1); + unlock_page(page); +release_out: + f2fs_put_page(page, 0); iput_out: iput(inode); } |