Patch "ext4: do not polute the extents cache while shifting extents" has been added to the 4.9-stable tree

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

ext4: do not polute the extents cache while shifting extents

to the 4.9-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:
ext4-do-not-polute-the-extents-cache-while-shifting-extents.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Roman Pen <[email protected]>
Date: Sun, 8 Jan 2017 21:00:35 -0500
Subject: ext4: do not polute the extents cache while shifting extents

From: Roman Pen <[email protected]>

commit 03e916fa8b5577d85471452a3d0c5738aa658dae upstream.

Inside ext4_ext_shift_extents() function ext4_find_extent() is called without EXT4_EX_NOCACHE flag, which should prevent cache population.

This leads to oudated offsets in the extents tree and wrong blocks afterwards.

Patch fixes the problem providing EXT4_EX_NOCACHE flag for each ext4_find_extents() call inside ext4_ext_shift_extents function.

---
 fs/ext4/extents.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

@@ -5344,7 +5344,8 @@ ext4_ext_shift_extents(struct inode *ino
 	ext4_lblk_t stop, *iterator, ex_start, ex_end;
 
 	/* Let path point to the last extent */
-	path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
+	path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
+				EXT4_EX_NOCACHE);
 	if (IS_ERR(path))
 		return PTR_ERR(path);
 

@@ -5360,7 +5361,8 @@ ext4_ext_shift_extents(struct inode *ino
 	 * sure the hole is big enough to accommodate the shift.
 	*/
 	if (SHIFT == SHIFT_LEFT) {
-		path = ext4_find_extent(inode, start - 1, &path, 0);
+		path = ext4_find_extent(inode, start - 1, &path,
+					EXT4_EX_NOCACHE);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
 		depth = path->p_depth;

@@ -5398,7 +5400,8 @@ ext4_ext_shift_extents(struct inode *ino
 	 * becomes NULL to indicate the end of the loop.
 	 */
 	while (iterator && start <= stop) {
-		path = ext4_find_extent(inode, *iterator, &path, 0);
+		path = ext4_find_extent(inode, *iterator, &path,
+					EXT4_EX_NOCACHE);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
 		depth = path->p_depth;

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

queue-4.9/ext4-include-forgotten-start-block-on-fallocate-insert-range.patch queue-4.9/ext4-do-not-polute-the-extents-cache-while-shifting-extents.patch