From: Nikolay Borisov <kernel@kyup.com>
Date: Thu, 2 Jul 2015 05:32:44 +0000 (-0400)
Subject: bufferhead: Add _gfp version for sb_getblk()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=bd7ade3cd9b0850264306f5c2b79024a417b6396;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

bufferhead: Add _gfp version for sb_getblk()

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>
Cc: stable@vger.kernel.org
---

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 73b45225a7ca..e6797ded700e 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -317,6 +317,13 @@ sb_getblk(struct super_block *sb, sector_t block)
 	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)
 {