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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 /fs/ext4/super.c | |
| 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 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c76962eba5dd..cc8c738480e8 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4207,7 +4207,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) /* Pre-read the descriptors into the buffer cache */ for (i = 0; i < db_count; i++) { block = descriptor_loc(sb, logical_sb_block, i); - sb_breadahead(sb, block); + sb_breadahead_unmovable(sb, block); } for (i = 0; i < db_count; i++) { |