From d87f639258a6a5980183f11876c884931ad93da2 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Fri, 28 Feb 2020 16:14:11 -0800 Subject: ext4: use non-movable memory for superblock readahead Since commit a8ac900b8163 ("ext4: use non-movable memory for the superblock") buffers for ext4 superblock were allocated using the sb_bread_unmovable() helper which allocated buffer heads out of non-movable memory blocks. It was necessarily to not block page migrations and do not cause cma allocation failures. However commit 85c8f176a611 ("ext4: preload block group descriptors") broke this by introducing pre-reading of the ext4 superblock. The problem is that __breadahead() is using __getblk() underneath, which allocates buffer heads out of movable memory. It resulted in page migration failures I've seen on a machine with an ext4 partition and a preallocated cma area. Fix this by introducing sb_breadahead_unmovable() and __breadahead_gfp() helpers which use non-movable memory for buffer head allocations and use them for the ext4 superblock readahead. Reviewed-by: Andreas Dilger Fixes: 85c8f176a611 ("ext4: preload block group descriptors") Signed-off-by: Roman Gushchin Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com Signed-off-by: Theodore Ts'o --- include/linux/buffer_head.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/buffer_head.h') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index e0b020eaf32e..15b765a181b8 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -189,6 +189,8 @@ struct buffer_head *__getblk_gfp(struct block_device *bdev, sector_t block, void __brelse(struct buffer_head *); void __bforget(struct buffer_head *); void __breadahead(struct block_device *, sector_t block, unsigned int size); +void __breadahead_gfp(struct block_device *, sector_t block, unsigned int size, + gfp_t gfp); struct buffer_head *__bread_gfp(struct block_device *, sector_t block, unsigned size, gfp_t gfp); void invalidate_bh_lrus(void); @@ -319,6 +321,12 @@ sb_breadahead(struct super_block *sb, sector_t block) __breadahead(sb->s_bdev, block, sb->s_blocksize); } +static inline void +sb_breadahead_unmovable(struct super_block *sb, sector_t block) +{ + __breadahead_gfp(sb->s_bdev, block, sb->s_blocksize, 0); +} + static inline struct buffer_head * sb_getblk(struct super_block *sb, sector_t block) { -- cgit v1.2.3 From 7b59435a2afed12dc9b2ec1b930efa2e94f1c397 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Mon, 1 Jun 2020 21:48:03 -0700 Subject: buffer_head.h: remove attach_page_buffers All the callers have replaced attach_page_buffers with the new function attach_page_private, so remove it. Signed-off-by: Guoqing Jiang Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Roman Gushchin Cc: Andreas Dilger Link: http://lkml.kernel.org/r/20200517214718.468-10-guoqing.jiang@cloud.ionos.com Signed-off-by: Linus Torvalds --- include/linux/buffer_head.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux/buffer_head.h') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 15b765a181b8..22fb11e2d2e0 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -272,14 +272,6 @@ void buffer_init(void); * inline definitions */ -static inline void attach_page_buffers(struct page *page, - struct buffer_head *head) -{ - get_page(page); - SetPagePrivate(page); - set_page_private(page, (unsigned long)head); -} - static inline void get_bh(struct buffer_head *bh) { atomic_inc(&bh->b_count); -- cgit v1.2.3