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f2fs: wait on atomic writes to count F2FS_CP_WB_DATA

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commit 31867b23d7d1ee3535136c6a410a6cf56f666bfc upstream.

Otherwise, we can get wrong counts incurring checkpoint hang.

IO_W (CP:  -24, Data:   24, Flush: (   0    0    1), Discard: (   0    0))

Thread A                        Thread B
- f2fs_write_data_pages
 -  __write_data_page
  - f2fs_submit_page_write
   - inc_page_count(F2FS_WB_DATA)
     type is F2FS_WB_DATA due to file is non-atomic one
- f2fs_ioc_start_atomic_write
 - set_inode_flag(FI_ATOMIC_FILE)
                                - f2fs_write_end_io
                                 - dec_page_count(F2FS_WB_CP_DATA)
                                   type is F2FS_WB_DATA due to file becomes
                                   atomic one

Cc: <stable@vger.kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jaegeuk Kim 2018-12-28 11:00:38 -08:00 committed by Greg Kroah-Hartman
parent 275a2c08c3
commit 2835c05972
1 changed files with 7 additions and 5 deletions
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10
fs/f2fs/file.c
View file

@ -1736,9 +1736,11 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
if (!get_dirty_pages(inode))
goto skip_flush;
/*
* Should wait end_io to count F2FS_WB_CP_DATA correctly by
* f2fs_is_atomic_file.
*/
if (get_dirty_pages(inode))
f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
"Unexpected flush for atomic writes: ino=%lu, npages=%u",
inode->i_ino, get_dirty_pages(inode));
@ -1747,7 +1749,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
goto out;
}
skip_flush:
set_inode_flag(inode, FI_ATOMIC_FILE);
clear_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST);
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);