[PATCH 3.16 044/366] ext4: factor out helper ext4_sample_last_mounted()

[Ben Hutchings <ben@xxxxxxxxxxxxxxx>]

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Amir Goldstein <amir73il@xxxxxxxxx>

commit 833a950882d33a7dfc319d5e152fdf35028936eb upstream.

Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
[bwh: Backported to 3.16:
 - Move up declaration of ret in ext4_file_open()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/ext4/file.c | 82 ++++++++++++++++++++++++++++----------------------
 1 file changed, 46 insertions(+), 36 deletions(-)

--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -208,52 +208,64 @@ static int ext4_file_mmap(struct file *f
 	return 0;
 }
 
-static int ext4_file_open(struct inode * inode, struct file * filp)
+static int ext4_sample_last_mounted(struct super_block *sb,
+				    struct vfsmount *mnt)
 {
-	struct super_block *sb = inode->i_sb;
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	struct vfsmount *mnt = filp->f_path.mnt;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct path path;
 	char buf[64], *cp;
+	handle_t *handle;
+	int err;
+
+	if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED))
+		return 0;
+
+	if (sb->s_flags & MS_RDONLY)
+		return 0;
+
+	sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
+	/*
+	 * Sample where the filesystem has been mounted and
+	 * store it in the superblock for sysadmin convenience
+	 * when trying to sort through large numbers of block
+	 * devices or filesystem images.
+	 */
+	memset(buf, 0, sizeof(buf));
+	path.mnt = mnt;
+	path.dentry = mnt->mnt_root;
+	cp = d_path(&path, buf, sizeof(buf));
+	if (IS_ERR(cp))
+		return 0;
+
+	handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	if (err)
+		goto out;
+	strlcpy(sbi->s_es->s_last_mounted, cp,
+		sizeof(sbi->s_es->s_last_mounted));
+	ext4_handle_dirty_super(handle, sb);
+out:
+	ext4_journal_stop(handle);
+	return err;
+}
+
+static int ext4_file_open(struct inode * inode, struct file * filp)
+{
+	int ret;
+
+	ret = ext4_sample_last_mounted(inode->i_sb, filp->f_path.mnt);
+	if (ret)
+		return ret;
 
-	if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
-		     !(sb->s_flags & MS_RDONLY))) {
-		sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
-		/*
-		 * Sample where the filesystem has been mounted and
-		 * store it in the superblock for sysadmin convenience
-		 * when trying to sort through large numbers of block
-		 * devices or filesystem images.
-		 */
-		memset(buf, 0, sizeof(buf));
-		path.mnt = mnt;
-		path.dentry = mnt->mnt_root;
-		cp = d_path(&path, buf, sizeof(buf));
-		if (!IS_ERR(cp)) {
-			handle_t *handle;
-			int err;
-
-			handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
-			if (IS_ERR(handle))
-				return PTR_ERR(handle);
-			BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
-			if (err) {
-				ext4_journal_stop(handle);
-				return err;
-			}
-			strlcpy(sbi->s_es->s_last_mounted, cp,
-				sizeof(sbi->s_es->s_last_mounted));
-			ext4_handle_dirty_super(handle, sb);
-			ext4_journal_stop(handle);
-		}
-	}
 	/*
 	 * Set up the jbd2_inode if we are opening the inode for
 	 * writing and the journal is present
 	 */
 	if (filp->f_mode & FMODE_WRITE) {
-		int ret = ext4_inode_attach_jinode(inode);
+		ret = ext4_inode_attach_jinode(inode);
 		if (ret < 0)
 			return ret;
 	}