linux/fs/f2fs
Hyeong-Jun Kim 7377e85396 f2fs: compress: fix potential deadlock of compress file
There is a potential deadlock between writeback process and a process
performing write_begin() or write_cache_pages() while trying to write
same compress file, but not compressable, as below:

[Process A] - doing checkpoint
[Process B]                     [Process C]
f2fs_write_cache_pages()
- lock_page() [all pages in cluster, 0-31]
- f2fs_write_multi_pages()
 - f2fs_write_raw_pages()
  - f2fs_write_single_data_page()
   - f2fs_do_write_data_page()
     - return -EAGAIN [f2fs_trylock_op() failed]
   - unlock_page(page) [e.g., page 0]
                                - generic_perform_write()
                                 - f2fs_write_begin()
                                  - f2fs_prepare_compress_overwrite()
                                   - prepare_compress_overwrite()
                                    - lock_page() [e.g., page 0]
                                    - lock_page() [e.g., page 1]
   - lock_page(page) [e.g., page 0]

Since there is no compress process, it is no longer necessary to hold
locks on every pages in cluster within f2fs_write_raw_pages().

This patch changes f2fs_write_raw_pages() to release all locks first
and then perform write same as the non-compress file in
f2fs_write_cache_pages().

Fixes: 4c8ff7095b ("f2fs: support data compression")
Signed-off-by: Hyeong-Jun Kim <hj514.kim@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-12-14 11:17:55 -08:00
..
acl.c vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
acl.h vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
checkpoint.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
compress.c f2fs: compress: fix potential deadlock of compress file 2021-12-14 11:17:55 -08:00
data.c f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file 2021-12-14 11:17:48 -08:00
debug.c f2fs: convert S_IRUGO to 0444 2021-08-17 11:59:05 -07:00
dir.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
extent_cache.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
f2fs.h f2fs: add gc_urgent_high_remaining sysfs node 2021-12-10 15:48:33 -08:00
file.c f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file 2021-12-14 11:17:48 -08:00
gc.c f2fs: add gc_urgent_high_remaining sysfs node 2021-12-10 15:48:33 -08:00
gc.h f2fs: introduce gc_merge mount option 2021-03-30 18:48:56 -07:00
hash.c f2fs: Handle casefolding with Encryption 2020-12-02 22:00:21 -08:00
inline.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
inode.c f2fs: fix remove page failed in invalidate compress pages 2021-12-10 15:48:32 -08:00
iostat.c f2fs: use iomap for direct I/O 2021-12-10 15:48:30 -08:00
iostat.h f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
Kconfig f2fs: implement iomap operations 2021-12-04 10:53:35 -08:00
Makefile f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
namei.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
node.c f2fs: set SBI_NEED_FSCK flag when inconsistent node block found 2021-09-20 16:29:00 -07:00
node.h f2fs: introduce excess_dirty_threshold() 2021-09-20 16:12:51 -07:00
recovery.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
segment.c f2fs: invalidate META_MAPPING before IPU/DIO write 2021-11-09 08:16:34 -08:00
segment.h f2fs: introduce fragment allocation mode mount option 2021-10-26 14:04:30 -07:00
shrinker.c f2fs: avoid race condition for shrinker count 2020-12-03 00:59:26 -08:00
super.c f2fs: add gc_urgent_high_remaining sysfs node 2021-12-10 15:48:33 -08:00
sysfs.c f2fs: add gc_urgent_high_remaining sysfs node 2021-12-10 15:48:33 -08:00
verity.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
xattr.c f2fs: support fault injection for dquot_initialize() 2021-10-29 10:38:53 -07:00
xattr.h f2fs: code cleanup by removing ifdef macro surrounding 2020-05-26 18:56:10 -07:00