Patch "bufferhead: Add _gfp version for sb_getblk()" has been added to the 4.1-stable tree

Patch "bufferhead: Add _gfp version for sb_getblk()" has been added to the 4.1-stable tree

[gregkh]

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

    bufferhead: Add _gfp version for sb_getblk()

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:
     bufferhead-add-_gfp-version-for-sb_getblk.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 bd7ade3cd9b0850264306f5c2b79024a417b6396 Mon Sep 17 00:00:00 2001
From: Nikolay Borisov <kernel@kyup.com>
Date: Thu, 2 Jul 2015 01:32:44 -0400
Subject: bufferhead: Add _gfp version for sb_getblk()

From: Nikolay Borisov <kernel@kyup.com>

commit bd7ade3cd9b0850264306f5c2b79024a417b6396 upstream.

sb_getblk() is used during ext4 (and possibly other FSes) writeback
paths. Sometimes such path require allocating memory and guaranteeing
that such allocation won't block. Currently, however, there is no way
to provide user flags for sb_getblk which could lead to deadlocks.

This patch implements a sb_getblk_gfp with the only difference it can
accept user-provided GFP flags.

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>

---
 include/linux/buffer_head.h |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -317,6 +317,13 @@ sb_getblk(struct super_block *sb, sector
 	return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE);
 }
 
+
+static inline struct buffer_head *
+sb_getblk_gfp(struct super_block *sb, sector_t block, gfp_t gfp)
+{
+	return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, gfp);
+}
+
 static inline struct buffer_head *
 sb_find_get_block(struct super_block *sb, sector_t block)
 {


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