Patch "reiserfs: Make flush bios explicitely sync" has been added to the 4.11-stable tree

This is a note to let you know that I've just added the patch titled

reiserfs: Make flush bios explicitely sync

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
reiserfs-make-flush-bios-explicitely-sync.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jan Kara <[email protected]>
Date: Tue, 2 May 2017 13:16:18 +0200
Subject: reiserfs: Make flush bios explicitely sync

From: Jan Kara <[email protected]>

commit d8747d642ec4ce96adf17ae35652a5e4015cfe02 upstream.

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...} definitions. generic_make_request_checks() however strips REQ_FUA and REQ_PREFLUSH flags from a bio when the storage doesn't report volatile write cache and thus write effectively becomes asynchronous which can lead to performance regressions

Fix the problem by making sure all bios which are synchronous are properly marked with REQ_SYNC.

---
 fs/reiserfs/journal.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -1112,7 +1112,7 @@ static int flush_commit_list(struct supe
 		depth = reiserfs_write_unlock_nested(s);
 		if (reiserfs_barrier_flush(s))
 			__sync_dirty_buffer(jl->j_commit_bh,
-					REQ_PREFLUSH | REQ_FUA);
+					REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
 		else
 			sync_dirty_buffer(jl->j_commit_bh);
 		reiserfs_write_lock_nested(s, depth);

@@ -1271,7 +1271,7 @@ static int _update_journal_header_block(
 
 		if (reiserfs_barrier_flush(sb))
 			__sync_dirty_buffer(journal->j_header_bh,
-					REQ_PREFLUSH | REQ_FUA);
+					REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
 		else
 			sync_dirty_buffer(journal->j_header_bh);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/reiserfs-make-flush-bios-explicitely-sync.patch queue-4.11/ext4-fix-data-corruption-with-ext4_get_blocks_zero.patch queue-4.11/cfq-iosched-fix-the-delay-of-cfq_group-s-vdisktime-under-iops-mode.patch queue-4.11/ext4-fix-fdatasync-2-after-extent-manipulation-operations.patch queue-4.11/gfs2-make-flush-bios-explicitely-sync.patch queue-4.11/block-avoid-that-blk_exit_rl-triggers-a-use-after-free.patch queue-4.11/ext4-fix-seek_hole.patch