diff options
| author | Jan Kara <jack@suse.cz> | 2017-02-10 00:50:56 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2017-02-10 00:50:56 -0500 |
| commit | d9b22cf9f5466a057f2a4f1e642b469fa9d73117 (patch) | |
| tree | 61fb0bf8028df1bd79ea44c4376b213dcd70249a | |
| parent | 168316db3583253b9e5d46392e5b9d03d531406f (diff) | |
| download | linux-d9b22cf9f5466a057f2a4f1e642b469fa9d73117.tar.bz2 | |
ext4: fix stripe-unaligned allocations
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>
| -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 f513f273ff89..10c62de642c6 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2146,8 +2146,10 @@ 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 */ @@ -2217,7 +2219,7 @@ 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)) |