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author | Sayali Lokhande <sayalil@codeaurora.org> | 2020-04-30 16:28:29 +0530 |
---|---|---|
committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2020-05-11 20:36:47 -0700 |
commit | 34c061ad85a2f5d5e9e3b045d72f3b211db6e282 (patch) | |
tree | 82291cc1ba147c8eaa395da771ccd4ea65807519 /fs/f2fs/checkpoint.c | |
parent | baaa7ebf25c78c5cb712fac16b7f549100beddd3 (diff) | |
download | linux-34c061ad85a2f5d5e9e3b045d72f3b211db6e282.tar.bz2 |
f2fs: Avoid double lock for cp_rwsem during checkpoint
There could be a scenario where f2fs_sync_node_pages gets
called during checkpoint, which in turn tries to flush
inline data and calls iput(). This results in deadlock as
iput() tries to hold cp_rwsem, which is already held at the
beginning by checkpoint->block_operations().
Call stack :
Thread A Thread B
f2fs_write_checkpoint()
- block_operations(sbi)
- f2fs_lock_all(sbi);
- down_write(&sbi->cp_rwsem);
- open()
- igrab()
- write() write inline data
- unlink()
- f2fs_sync_node_pages()
- if (is_inline_node(page))
- flush_inline_data()
- ilookup()
page = f2fs_pagecache_get_page()
if (!page)
goto iput_out;
iput_out:
-close()
-iput()
iput(inode);
- f2fs_evict_inode()
- f2fs_truncate_blocks()
- f2fs_lock_op()
- down_read(&sbi->cp_rwsem);
Fixes: 2049d4fcb057 ("f2fs: avoid multiple node page writes due to inline_data")
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/checkpoint.c')
-rw-r--r-- | fs/f2fs/checkpoint.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index d49f7a01d8a2..79e605f38f4f 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1168,6 +1168,11 @@ static int block_operations(struct f2fs_sb_info *sbi) }; int err = 0, cnt = 0; + /* + * Let's flush inline_data in dirty node pages. + */ + f2fs_flush_inline_data(sbi); + retry_flush_quotas: f2fs_lock_all(sbi); if (__need_flush_quota(sbi)) { |