From aa750fd71c242dba02ee2034e15fbd7d0cdb2461 Mon Sep 17 00:00:00 2001 From: Junichi Nomura Date: Thu, 5 Nov 2015 18:47:23 -0800 Subject: mm/filemap.c: make global sync not clear error status of individual inodes filemap_fdatawait() is a function to wait for on-going writeback to complete but also consume and clear error status of the mapping set during writeback. The latter functionality is critical for applications to detect writeback error with system calls like fsync(2)/fdatasync(2). However filemap_fdatawait() is also used by sync(2) or FIFREEZE ioctl, which don't check error status of individual mappings. As a result, fsync() may not be able to detect writeback error if events happen in the following order: Application System admin ---------------------------------------------------------- write data on page cache Run sync command writeback completes with error filemap_fdatawait() clears error fsync returns success (but the data is not on disk) This patch adds filemap_fdatawait_keep_errors() for call sites where writeback error is not handled so that they don't clear error status. Signed-off-by: Jun'ichi Nomura Acked-by: Andi Kleen Reviewed-by: Tejun Heo Cc: Fengguang Wu Cc: Dave Chinner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 72d8a844c692..9355f377fd46 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2422,6 +2422,7 @@ extern int write_inode_now(struct inode *, int); extern int filemap_fdatawrite(struct address_space *); extern int filemap_flush(struct address_space *); extern int filemap_fdatawait(struct address_space *); +extern void filemap_fdatawait_keep_errors(struct address_space *); extern int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); extern int filemap_write_and_wait(struct address_space *mapping); -- cgit v1.2.3