From d32a93f05187684c8a0bab5cfac3741ad4c01c30 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 1 Oct 2017 17:59:54 -0400 Subject: [PATCH] ext4: retry allocations conservatively Now that we no longer try to reserve metadata blocks for delayed allocations (which tended to overestimate the required number of blocks significantly), we really don't need retry allocations when the disk is very full as aggressively any more. The only time when it makes sense to retry an allocation is if we have freshly deleted blocks that will only become available after a transaction commit. And if we lose that race, it's not worth it to try more than once. Signed-off-by: Theodore Ts'o --- fs/ext4/balloc.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index e04ec868e37e7..a3798b25a8dcc 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -600,22 +600,21 @@ int ext4_claim_free_clusters(struct ext4_sb_info *sbi, * ext4_should_retry_alloc() is called when ENOSPC is returned, and if * it is profitable to retry the operation, this function will wait * for the current or committing transaction to complete, and then - * return TRUE. - * - * if the total number of retries exceed three times, return FALSE. + * return TRUE. We will only retry once. */ int ext4_should_retry_alloc(struct super_block *sb, int *retries) { if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) || - (*retries)++ > 3 || + (*retries)++ > 1 || !EXT4_SB(sb)->s_journal) return 0; - jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); - smp_mb(); - if (EXT4_SB(sb)->s_mb_free_pending) - jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); + if (EXT4_SB(sb)->s_mb_free_pending == 0) + return 0; + + jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); + jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); return 1; } -- 2.39.5