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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-02 17:25:22 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-02 17:25:22 -0400 |
| commit | 6d7d0603ca7c397a07efc88e314e38b4242a3a8d (patch) | |
| tree | db8072825fd71da64117fbf9cf056af65dcf061d | |
| parent | e0178b546d24f42a85f4d4da080fb801e0d49107 (diff) | |
| parent | 3582e74599d376bc18cae123045cd295360d885b (diff) | |
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fix from Ted Ts'o:
"Fix an ext4 regression which landed during the 6.4 merge window"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
Revert "ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits"
| -rw-r--r-- | fs/ext4/mballoc.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 7b2e36d103cb..20f67a260df5 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2062,7 +2062,7 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac, if (bex->fe_len < gex->fe_len) return; - if (finish_group) + if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan) ext4_mb_use_best_found(ac, e4b); } @@ -2074,6 +2074,20 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac, * in the context. Later, the best found extent will be used, if * mballoc can't find good enough extent. * + * The algorithm used is roughly as follows: + * + * * If free extent found is exactly as big as goal, then + * stop the scan and use it immediately + * + * * If free extent found is smaller than goal, then keep retrying + * upto a max of sbi->s_mb_max_to_scan times (default 200). After + * that stop scanning and use whatever we have. + * + * * If free extent found is bigger than goal, then keep retrying + * upto a max of sbi->s_mb_min_to_scan times (default 10) before + * stopping the scan and using the extent. + * + * * FIXME: real allocation policy is to be designed yet! */ static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, |