Patch "ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

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

    ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp

to the 4.1-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-avoid-deadlocks-in-the-writeback-path-by-using-sb_getblk_gfp.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From c45653c341f5c8a0ce19c8f0ad4678640849cb86 Mon Sep 17 00:00:00 2001
From: Nikolay Borisov <kernel@kyup.com>
Date: Thu, 2 Jul 2015 01:34:07 -0400
Subject: ext4: avoid deadlocks in the writeback path by using sb_getblk_gfp

From: Nikolay Borisov <kernel@kyup.com>

commit c45653c341f5c8a0ce19c8f0ad4678640849cb86 upstream.

Switch ext4 to using sb_getblk_gfp with GFP_NOFS added to fix possible
deadlocks in the page writeback path.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -503,7 +503,7 @@ __read_extent_tree_block(const char *fun
 	struct buffer_head		*bh;
 	int				err;
 
-	bh = sb_getblk(inode->i_sb, pblk);
+	bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
 	if (unlikely(!bh))
 		return ERR_PTR(-ENOMEM);
 
@@ -1088,7 +1088,7 @@ static int ext4_ext_split(handle_t *hand
 		err = -EIO;
 		goto cleanup;
 	}
-	bh = sb_getblk(inode->i_sb, newblock);
+	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
 	if (unlikely(!bh)) {
 		err = -ENOMEM;
 		goto cleanup;
@@ -1282,7 +1282,7 @@ static int ext4_ext_grow_indepth(handle_
 	if (newblock == 0)
 		return err;
 
-	bh = sb_getblk(inode->i_sb, newblock);
+	bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
 	if (unlikely(!bh))
 		return -ENOMEM;
 	lock_buffer(bh);


Patches currently in stable-queue which might be from kernel@kyup.com are

queue-4.1/bufferhead-add-_gfp-version-for-sb_getblk.patch
queue-4.1/ext4-avoid-deadlocks-in-the-writeback-path-by-using-sb_getblk_gfp.patch