From 74e9374ed552160261e29647bf6e1907cdd27523 Mon Sep 17 00:00:00 2001 From: Gioh Kim Date: Thu, 4 Sep 2014 22:04:42 -0400 Subject: fs/buffer.c: support buffer cache allocations with gfp modifiers commit 3b5e6454aaf6b4439b19400d8365e2ec2d24e411 upstream. A buffer cache is allocated from movable area because it is referred for a while and released soon. But some filesystems are taking buffer cache for a long time and it can disturb page migration. New APIs are introduced to allocate buffer cache with user specific flag. *_gfp APIs are for user want to set page allocation flag for page cache allocation. And *_unmovable APIs are for the user wants to allocate page cache from non-movable area. Signed-off-by: Gioh Kim Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara [bwh: Prerequisite for "bufferhead: Add _gfp version for sb_getblk()". Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- include/linux/buffer_head.h | 47 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 458f497..1738420 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -166,12 +166,13 @@ void __wait_on_buffer(struct buffer_head *); wait_queue_head_t *bh_waitq_head(struct buffer_head *bh); struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block, unsigned size); -struct buffer_head *__getblk(struct block_device *bdev, sector_t block, - unsigned size); +struct buffer_head *__getblk_gfp(struct block_device *bdev, sector_t block, + unsigned size, gfp_t gfp); void __brelse(struct buffer_head *); void __bforget(struct buffer_head *); void __breadahead(struct block_device *, sector_t block, unsigned int size); -struct buffer_head *__bread(struct block_device *, sector_t block, unsigned size); +struct buffer_head *__bread_gfp(struct block_device *, + sector_t block, unsigned size, gfp_t gfp); void invalidate_bh_lrus(void); struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); void free_buffer_head(struct buffer_head * bh); @@ -286,7 +287,13 @@ static inline void bforget(struct buffer_head *bh) static inline struct buffer_head * sb_bread(struct super_block *sb, sector_t block) { - return __bread(sb->s_bdev, block, sb->s_blocksize); + return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE); +} + +static inline struct buffer_head * +sb_bread_unmovable(struct super_block *sb, sector_t block) +{ + return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, 0); } static inline void @@ -298,7 +305,7 @@ sb_breadahead(struct super_block *sb, sector_t block) static inline struct buffer_head * sb_getblk(struct super_block *sb, sector_t block) { - return __getblk(sb->s_bdev, block, sb->s_blocksize); + return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE); } static inline struct buffer_head * @@ -335,6 +342,36 @@ static inline void lock_buffer(struct buffer_head *bh) __lock_buffer(bh); } +static inline struct buffer_head *getblk_unmovable(struct block_device *bdev, + sector_t block, + unsigned size) +{ + return __getblk_gfp(bdev, block, size, 0); +} + +static inline struct buffer_head *__getblk(struct block_device *bdev, + sector_t block, + unsigned size) +{ + return __getblk_gfp(bdev, block, size, __GFP_MOVABLE); +} + +/** + * __bread() - reads a specified block and returns the bh + * @bdev: the block_device to read from + * @block: number of block + * @size: size (in bytes) to read + * + * Reads a specified block, and returns buffer head that contains it. + * The page cache is allocated from movable area so that it can be migrated. + * It returns NULL if the block was unreadable. + */ +static inline struct buffer_head * +__bread(struct block_device *bdev, sector_t block, unsigned size) +{ + return __bread_gfp(bdev, block, size, __GFP_MOVABLE); +} + extern int __set_page_dirty_buffers(struct page *page); #else /* CONFIG_BLOCK */ -- cgit v1.1