ext4 fast_commit: make use of name_snapshot primitives

... rather than open-coding them.  As a bonus, that avoids the pointless
work with extra allocations, etc. for long names.

Reviewed-by: Jeff Layton <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Al Viro <[email protected]>

Author: Al Viro

fs/ext4/fast_commit.c

@@ -322,9 +322,7 @@ void ext4_fc_del(struct inode *inode)
 	WARN_ON(!list_empty(&ei->i_fc_dilist));
 	spin_unlock(&sbi->s_fc_lock);
 
-	if (fc_dentry->fcd_name.name &&
-		fc_dentry->fcd_name.len > DNAME_INLINE_LEN)
-		kfree(fc_dentry->fcd_name.name);
+	release_dentry_name_snapshot(&fc_dentry->fcd_name);
 	kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry);
 
 	return;
@@ -449,22 +447,7 @@ static int __track_dentry_update(handle_t *handle, struct inode *inode,
 	node->fcd_op = dentry_update->op;
 	node->fcd_parent = dir->i_ino;
 	node->fcd_ino = inode->i_ino;
-	if (dentry->d_name.len > DNAME_INLINE_LEN) {
-		node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS);
-		if (!node->fcd_name.name) {
-			kmem_cache_free(ext4_fc_dentry_cachep, node);
-			ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, handle);
-			mutex_lock(&ei->i_fc_lock);
-			return -ENOMEM;
-		}
-		memcpy((u8 *)node->fcd_name.name, dentry->d_name.name,
-			dentry->d_name.len);
-	} else {
-		memcpy(node->fcd_iname, dentry->d_name.name,
-			dentry->d_name.len);
-		node->fcd_name.name = node->fcd_iname;
-	}
-	node->fcd_name.len = dentry->d_name.len;
+	take_dentry_name_snapshot(&node->fcd_name, dentry);
 	INIT_LIST_HEAD(&node->fcd_dilist);
 	spin_lock(&sbi->s_fc_lock);
 	if (sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
@@ -832,7 +815,7 @@ static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u32 *crc,
 {
 	struct ext4_fc_dentry_info fcd;
 	struct ext4_fc_tl tl;
-	int dlen = fc_dentry->fcd_name.len;
+	int dlen = fc_dentry->fcd_name.name.len;
 	u8 *dst = ext4_fc_reserve_space(sb,
 			EXT4_FC_TAG_BASE_LEN + sizeof(fcd) + dlen, crc);
 
@@ -847,7 +830,7 @@ static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u32 *crc,
 	dst += EXT4_FC_TAG_BASE_LEN;
 	memcpy(dst, &fcd, sizeof(fcd));
 	dst += sizeof(fcd);
-	memcpy(dst, fc_dentry->fcd_name.name, dlen);
+	memcpy(dst, fc_dentry->fcd_name.name.name, dlen);
 
 	return true;
 }
@@ -1328,9 +1311,7 @@ static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid)
 		list_del_init(&fc_dentry->fcd_dilist);
 		spin_unlock(&sbi->s_fc_lock);
 
-		if (fc_dentry->fcd_name.name &&
-			fc_dentry->fcd_name.len > DNAME_INLINE_LEN)
-			kfree(fc_dentry->fcd_name.name);
+		release_dentry_name_snapshot(&fc_dentry->fcd_name);
 		kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry);
 		spin_lock(&sbi->s_fc_lock);
 	}

fs/ext4/fast_commit.h

@@ -109,8 +109,7 @@ struct ext4_fc_dentry_update {
 	int fcd_op;		/* Type of update create / unlink / link */
 	int fcd_parent;		/* Parent inode number */
 	int fcd_ino;		/* Inode number */
-	struct qstr fcd_name;	/* Dirent name */
-	unsigned char fcd_iname[DNAME_INLINE_LEN];	/* Dirent name string */
+	struct name_snapshot fcd_name;	/* Dirent name */
 	struct list_head fcd_list;
 	struct list_head fcd_dilist;
 };