From d08854f5bcf3ea0cabc6fd2fc49c2d97e00c7c88 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 26 Jun 2016 18:24:01 -0400 Subject: [PATCH] ext4: optimize ext4_should_retry_alloc() to improve ENOSPC performance If there are no pending blocks to be released after a commit, forcing a journal commit has no hope of helping. It's possible that a commit had just completed, so if there are now free blocks available for allocation, it's worth retrying the commit. Reported-by: Chao Yu Signed-off-by: Theodore Ts'o --- fs/ext4/balloc.c | 4 +++- fs/ext4/ext4.h | 1 + fs/ext4/ext4_jbd2.h | 10 +++++++++- fs/ext4/mballoc.c | 12 ++++++++++-- 4 files changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 3020fd70c392..0b8105b3293d 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -610,7 +610,9 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries) jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); - jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); + smp_mb(); + if (EXT4_SB(sb)->s_mb_free_pending) + jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); return 1; } diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index b84aa1ca480a..96c73e6fec6e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1430,6 +1430,7 @@ struct ext4_sb_info { unsigned short *s_mb_offsets; unsigned int *s_mb_maxs; unsigned int s_group_info_size; + unsigned int s_mb_free_pending; /* tunables */ unsigned long s_stripe; diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index 09c1ef38cbe6..b1d52c14098e 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -175,6 +175,13 @@ struct ext4_journal_cb_entry { * There is no guaranteed calling order of multiple registered callbacks on * the same transaction. */ +static inline void _ext4_journal_callback_add(handle_t *handle, + struct ext4_journal_cb_entry *jce) +{ + /* Add the jce to transaction's private list */ + list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list); +} + static inline void ext4_journal_callback_add(handle_t *handle, void (*func)(struct super_block *sb, struct ext4_journal_cb_entry *jce, @@ -187,10 +194,11 @@ static inline void ext4_journal_callback_add(handle_t *handle, /* Add the jce to transaction's private list */ jce->jce_func = func; spin_lock(&sbi->s_md_lock); - list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list); + _ext4_journal_callback_add(handle, jce); spin_unlock(&sbi->s_md_lock); } + /** * ext4_journal_callback_del: delete a registered callback * @handle: active journal transaction handle on which callback was registered diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index c1ab3ec30423..77249e1f5c3a 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2627,6 +2627,7 @@ int ext4_mb_init(struct super_block *sb) spin_lock_init(&sbi->s_md_lock); spin_lock_init(&sbi->s_bal_lock); + sbi->s_mb_free_pending = 0; sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; @@ -2814,6 +2815,9 @@ static void ext4_free_data_callback(struct super_block *sb, /* we expect to find existing buddy because it's pinned */ BUG_ON(err != 0); + spin_lock(&EXT4_SB(sb)->s_md_lock); + EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count; + spin_unlock(&EXT4_SB(sb)->s_md_lock); db = e4b.bd_info; /* there are blocks to put in buddy to make them really free */ @@ -4583,6 +4587,7 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, { ext4_group_t group = e4b->bd_group; ext4_grpblk_t cluster; + ext4_grpblk_t clusters = new_entry->efd_count; struct ext4_free_data *entry; struct ext4_group_info *db = e4b->bd_info; struct super_block *sb = e4b->bd_sb; @@ -4649,8 +4654,11 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, } } /* Add the extent to transaction's private list */ - ext4_journal_callback_add(handle, ext4_free_data_callback, - &new_entry->efd_jce); + new_entry->efd_jce.jce_func = ext4_free_data_callback; + spin_lock(&sbi->s_md_lock); + _ext4_journal_callback_add(handle, &new_entry->efd_jce); + sbi->s_mb_free_pending += clusters; + spin_unlock(&sbi->s_md_lock); return 0; } -- 2.20.1