Commit dfa74280 authored Jun 04, 2018 by Chao Yu Committed by Jaegeuk Kim Jun 04, 2018

f2fs: fix to clear FI_VOLATILE_FILE correctly



Thread A			Thread B
- f2fs_release_file
 - clear_inode_flag(FI_VOLATILE_FILE)
				- wb_writeback
				 - writeback_sb_inodes
				  - __writeback_single_inode
				   - do_writepages
				    - f2fs_write_data_pages
				     - __write_data_page
				     all volatile file's pages
				     are writebacked to storage
 - set_inode_flag(FI_DROP_CACHE)
 - filemap_fdatawrite

There is a hole that mm can flush all dirty pages of volatile file as
inode is not tagged with both FI_VOLATILE_FILE and FI_DROP_CACHE flags,
we should never writeback the page #0 and also it's unneeded to writeback
other pages.

This patch adjusts to relocate clear_inode_flag(FI_VOLATILE_FILE), so that
FI_VOLATILE_FILE flag can be remained before all dirty pages were dropped
to avoid issue.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

parent c29fd0c0

fs/f2fs/file.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1564,11 +1564,11 @@ static int f2fs_release_file(struct inode inode, struct file filp)
		if (f2fs_is_atomic_file(inode))
		f2fs_drop_inmem_pages(inode);
		if (f2fs_is_volatile_file(inode)) {
		clear_inode_flag(inode, FI_VOLATILE_FILE);
		stat_dec_volatile_write(inode);
		set_inode_flag(inode, FI_DROP_CACHE);
		filemap_fdatawrite(inode->i_mapping);
		clear_inode_flag(inode, FI_DROP_CACHE);
		clear_inode_flag(inode, FI_VOLATILE_FILE);
		stat_dec_volatile_write(inode);
		}
		return 0;
		}

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