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Message-Id: <1465353418-12897-1-git-send-email-tytso@mit.edu>
Date: Tue, 7 Jun 2016 22:36:58 -0400
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: Theodore Ts'o <tytso@....edu>
Subject: [PATCH] ext4: optimize ext4_should_retry_alloc() to improve ENOSPC performance
If there are pending blocks to be released after a commit, retrying
the allocation after a journal commit has no hope of helping. So
track how many pending deleted blocks there might be, and don't retry
if there are no pending blocks.
Reported-by: Chao Yu <yuchao0@...wei.com>
Signed-off-by: Theodore Ts'o <tytso@....edu>
---
fs/ext4/balloc.c | 9 ++++++++-
fs/ext4/ext4.h | 1 +
fs/ext4/ext4_jbd2.h | 10 +++++++++-
fs/ext4/fsync.c | 5 +++--
fs/ext4/mballoc.c | 12 ++++++++++--
5 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 3020fd7..371ac63 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -603,7 +603,14 @@ int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
*/
int ext4_should_retry_alloc(struct super_block *sb, int *retries)
{
- if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
+ unsigned int pending_blocks;
+
+ spin_lock(&EXT4_SB(sb)->s_md_lock);
+ pending_blocks = EXT4_SB(sb)->s_mb_free_pending;
+ spin_unlock(&EXT4_SB(sb)->s_md_lock);
+
+ if (pending_blocks == 0 ||
+ !ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
(*retries)++ > 3 ||
!EXT4_SB(sb)->s_journal)
return 0;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b84aa1c..96c73e6 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 09c1ef3..b1d52c1 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/fsync.c b/fs/ext4/fsync.c
index 8850254..7ee4abd 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -106,10 +106,10 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
}
if (!journal) {
- ret = generic_file_fsync(file, start, end, datasync);
+ ret = __generic_file_fsync(file, start, end, datasync);
if (!ret && !hlist_empty(&inode->i_dentry))
ret = ext4_sync_parent(inode);
- goto out;
+ goto issue_flush;
}
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
@@ -140,6 +140,7 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
needs_barrier = true;
ret = jbd2_complete_transaction(journal, commit_tid);
if (needs_barrier) {
+ issue_flush:
err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
if (!ret)
ret = err;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c1ab3ec..77249e1 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;
}
--
2.5.0
--
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