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| author | Roman Gushchin <guro@fb.com> | 2020-02-29 03:14:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-23 11:30:12 +0300 |
| commit | a6375c9877a81896837c79877fef874bc8a2023b (patch) | |
| tree | 8841d4c5eaf613f03b5928b870c4e8f673c576d4 /include | |
| parent | 45533ebd5e5ceb5b0cbb865c3e67adaff65356b1 (diff) | |
| download | linux-a6375c9877a81896837c79877fef874bc8a2023b.tar.xz | |
ext4: use non-movable memory for superblock readahead
commit d87f639258a6a5980183f11876c884931ad93da2 upstream.
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 <adilger@dilger.ca>
Fixes: 85c8f176a611 ("ext4: preload block group descriptors")
Signed-off-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/buffer_head.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 96225a77c112..9168fc33a4f7 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) { |