diff options
| author | Jan Kara <jack@suse.cz> | 2017-10-07 22:37:45 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-08 10:06:29 +0100 |
| commit | 5624ea1610407db30f1adaf896f6d9c3cb66f072 (patch) | |
| tree | d4554f7b48fdb2d32ab6b3515e68e9f88cb33729 /fs | |
| parent | a76eb0e8655ef8cf58917549f667e8c9a9be1fc6 (diff) | |
ext4: fix stripe-unaligned allocations
[ Upstream commit d9b22cf9f5466a057f2a4f1e642b469fa9d73117 ]
When a filesystem is created using:
mkfs.ext4 -b 4096 -E stride=512 <dev>
and we try to allocate 64MB extent, we will end up directly in
ext4_mb_complex_scan_group(). This is because the request is detected
as power-of-two allocation (so we start in ext4_mb_regular_allocator()
with ac_criteria == 0) however the check before
ext4_mb_simple_scan_group() refuses the direct buddy scan because the
allocation request is too large. Since cr == 0, the check whether we
should use ext4_mb_scan_aligned() fails as well and we fall back to
ext4_mb_complex_scan_group().
Fix the problem by checking for upper limit on power-of-two requests
directly when detecting them.
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/mballoc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 84cd77663e1f..1ba82dc5afa3 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2136,8 +2136,10 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) * We search using buddy data only if the order of the request * is greater than equal to the sbi_s_mb_order2_reqs * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req + * We also support searching for power-of-two requests only for + * requests upto maximum buddy size we have constructed. */ - if (i >= sbi->s_mb_order2_reqs) { + if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) { /* * This should tell if fe_len is exactly power of 2 */ @@ -2207,7 +2209,7 @@ repeat: } ac->ac_groups_scanned++; - if (cr == 0 && ac->ac_2order < sb->s_blocksize_bits+2) + if (cr == 0) ext4_mb_simple_scan_group(ac, &e4b); else if (cr == 1 && sbi->s_stripe && !(ac->ac_g_ex.fe_len % sbi->s_stripe)) |