From 31867b23d7d1ee3535136c6a410a6cf56f666bfc Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Fri, 28 Dec 2018 11:00:38 -0800
Subject: [PATCH] f2fs: wait on atomic writes to count F2FS_CP_WB_DATA
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>
---
fs/f2fs/file.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index bba56b39dcc55..ae2b45e758473 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1750,10 +1750,12 @@ 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;
-
- f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
+ /*
+ * 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));
ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
@@ -1761,7 +1763,7 @@ 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]);
--
2.39.5