bufferhead: Add _gfp version for sb_getblk()

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: Zefan Li <lizefan@huawei.com>

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 1738420c5b5a9a220dada119c191b55b9030de6c..fed3f3ac489da0a3490e5f8f4fc70c418a1d3ffc 100644 (file)
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -308,6 +308,13 @@ 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)
 {