4.17-stable review patch. If anyone has any objections, please let me know.
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From: Chao Yu yuchao0@huawei.com
[ Upstream commit 27319ba4044c0c67d62ae39e53c0118c89f0a029 ]
Thread GC thread - f2fs_ioc_start_atomic_write - get_dirty_pages - filemap_write_and_wait_range - f2fs_gc - do_garbage_collect - gc_data_segment - move_data_page - f2fs_is_atomic_file - set_page_dirty - set_inode_flag(, FI_ATOMIC_FILE)
Dirty data page can still be generated by GC in race condition as above call stack.
This patch adds fi->dio_rwsem[WRITE] in f2fs_ioc_start_atomic_write to avoid such race.
Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/file.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1670,6 +1670,8 @@ static int f2fs_ioc_start_atomic_write(s
inode_lock(inode);
+ down_write(&F2FS_I(inode)->dio_rwsem[WRITE]); + if (f2fs_is_atomic_file(inode)) goto out;
@@ -1699,6 +1701,7 @@ inc_stat: stat_inc_atomic_write(inode); stat_update_max_atomic_write(inode); out: + up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); inode_unlock(inode); mnt_drop_write_file(filp); return ret;