[PATCH 2/2] ext4: Move quota initialization out of inode allocation transaction

[Jan Kara <jack@suse.cz>]

Inode allocation transaction is pretty heavy (246 credits with quotas
and extents before previous patch, still around 200 after it).  This is
mostly due to credits required for allocation of quota structures
(credits there are heavily overestimated but it's difficult to make
better estimates if we don't want to wire non-trivial assumptions about
quota format into filesystem).

So move quota initialization out of allocation transaction. That way
transaction for quota structure allocation will be started only if we
need to look up quota structure on disk (rare) and furthermore it will
be started for each quota type separately, not for all of them at once.
This reduces maximum transaction size to 34 is most cases and to 73 in
the worst case.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ialloc.c |   62 +++++++++++++++++++++++++++---------------------------
 fs/ext4/namei.c  |   12 +++-------
 2 files changed, 35 insertions(+), 39 deletions(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 6c5bb8d..3f37297 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -652,6 +652,7 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 	struct inode *ret;
 	ext4_group_t i;
 	ext4_group_t flex_group;
+	bool quota_allocated = false;
 
 	/* Cannot create files in a deleted directory */
 	if (!dir || !dir->i_nlink)
@@ -666,6 +667,23 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 	ei = EXT4_I(inode);
 	sbi = EXT4_SB(sb);
 
+	/*
+	 * Initalize owners and quota early so that we don't have to account
+	 * for quota initialization worst case in standard inode creating
+	 * transaction
+	 */
+	if (owner) {
+		inode->i_mode = mode;
+		i_uid_write(inode, owner[0]);
+		i_gid_write(inode, owner[1]);
+	} else if (test_opt(sb, GRPID)) {
+		inode->i_mode = mode;
+		inode->i_uid = current_fsuid();
+		inode->i_gid = dir->i_gid;
+	} else
+		inode_init_owner(inode, dir, mode);
+	dquot_initialize(inode);
+
 	if (!goal)
 		goal = sbi->s_inode_goal;
 
@@ -851,17 +869,6 @@ got:
 		flex_group = ext4_flex_group(sbi, group);
 		atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
 	}
-	if (owner) {
-		inode->i_mode = mode;
-		i_uid_write(inode, owner[0]);
-		i_gid_write(inode, owner[1]);
-	} else if (test_opt(sb, GRPID)) {
-		inode->i_mode = mode;
-		inode->i_uid = current_fsuid();
-		inode->i_gid = dir->i_gid;
-	} else
-		inode_init_owner(inode, dir, mode);
-
 	inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
 	/* This is the optimal IO size (for stat), not the fs block size */
 	inode->i_blocks = 0;
@@ -918,18 +925,18 @@ got:
 		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
 
 	ret = inode;
-	dquot_initialize(inode);
 	err = dquot_alloc_inode(inode);
 	if (err)
-		goto fail_drop;
+		goto out;
+	quota_allocated = true;
 
 	err = ext4_init_acl(handle, inode, dir);
 	if (err)
-		goto fail_free_drop;
+		goto out;
 
 	err = ext4_init_security(handle, inode, dir, qstr);
 	if (err)
-		goto fail_free_drop;
+		goto out;
 
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 		/* set extent flag only for directory, file and normal symlink*/
@@ -945,10 +952,8 @@ got:
 	}
 
 	err = ext4_mark_inode_dirty(handle, inode);
-	if (err) {
-		ext4_std_error(sb, err);
-		goto fail_free_drop;
-	}
+	if (err)
+		goto fail;
 
 	ext4_debug("allocating inode %lu\n", inode->i_ino);
 	trace_ext4_allocate_inode(inode, dir, mode);
@@ -956,23 +961,18 @@ got:
 fail:
 	ext4_std_error(sb, err);
 out:
-	iput(inode);
-	ret = ERR_PTR(err);
-really_out:
-	brelse(inode_bitmap_bh);
-	return ret;
-
-fail_free_drop:
-	dquot_free_inode(inode);
-
-fail_drop:
+	if (quota_allocated)
+		dquot_free_inode(inode);
 	dquot_drop(inode);
 	inode->i_flags |= S_NOQUOTA;
 	clear_nlink(inode);
-	unlock_new_inode(inode);
+	if (inode->i_state & I_NEW)
+		unlock_new_inode(inode);
 	iput(inode);
+	ret = ERR_PTR(err);
+really_out:
 	brelse(inode_bitmap_bh);
-	return ERR_PTR(err);
+	return ret;
 }
 
 /* Verify that we are loading a valid orphan from disk */
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 3825d6a..ede1337 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2251,8 +2251,7 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 	dquot_initialize(dir);
 
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
-		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
-		   EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
 	inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
 					    NULL, EXT4_HT_DIR, credits);
@@ -2286,8 +2285,7 @@ static int ext4_mknod(struct inode *dir, struct dentry *dentry,
 	dquot_initialize(dir);
 
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
-		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
-		   EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
 	inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
 					    NULL, EXT4_HT_DIR, credits);
@@ -2396,8 +2394,7 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	dquot_initialize(dir);
 
 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
-		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
-		   EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
 retry:
 	inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
 					    &dentry->d_name,
@@ -2826,8 +2823,7 @@ static int ext4_symlink(struct inode *dir,
 		 * quota blocks, sb is already counted in previous macros).
 		 */
 		credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
-			  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
-			  EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
+			  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
 	}
 retry:
 	inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
-- 
1.7.1