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| author | Roman Gushchin <guro@fb.com> | 2020-02-28 16:14:11 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-24 08:01:00 +0200 |
| commit | 73a55c0a66a5bb60297c1c98fcbc62b0507878dd (patch) | |
| tree | f0ac92462a190094c29af027a8d0b4164780f45d /fs/buffer.c | |
| parent | c1ac17ab54ee38924670911d800ddfc8b1d610a1 (diff) | |
| download | linux-stable-73a55c0a66a5bb60297c1c98fcbc62b0507878dd.tar.gz linux-stable-73a55c0a66a5bb60297c1c98fcbc62b0507878dd.tar.bz2 linux-stable-73a55c0a66a5bb60297c1c98fcbc62b0507878dd.zip | |
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 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index bdca7b10e239..cae7f24a0410 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1398,6 +1398,17 @@ void __breadahead(struct block_device *bdev, sector_t block, unsigned size) } EXPORT_SYMBOL(__breadahead); +void __breadahead_gfp(struct block_device *bdev, sector_t block, unsigned size, + gfp_t gfp) +{ + struct buffer_head *bh = __getblk_gfp(bdev, block, size, gfp); + if (likely(bh)) { + ll_rw_block(REQ_OP_READ, REQ_RAHEAD, 1, &bh); + brelse(bh); + } +} +EXPORT_SYMBOL(__breadahead_gfp); + /** * __bread_gfp() - reads a specified block and returns the bh * @bdev: the block_device to read from |