ext4: rename journal_dev to s_journal_dev inside ext4_sb_info

Rename journal_dev to s_journal_dev inside ext4_sb_info, keep
the naming rules consistent with other variables, which is
convenient for code reading and writing.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/1600916623-544-1-git-send-email-brookxu@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 593eb12..b2f654f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -950,10 +950,10 @@ static void ext4_blkdev_put(struct block_device *bdev)
 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 {
 	struct block_device *bdev;
-	bdev = sbi->journal_bdev;
+	bdev = sbi->s_journal_bdev;
 	if (bdev) {
 		ext4_blkdev_put(bdev);
-		sbi->journal_bdev = NULL;
+		sbi->s_journal_bdev = NULL;
 	}
 }
 
@@ -1084,14 +1084,14 @@ static void ext4_put_super(struct super_block *sb)
 
 	sync_blockdev(sb->s_bdev);
 	invalidate_bdev(sb->s_bdev);
-	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
+	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
 		/*
 		 * Invalidate the journal device's buffers.  We don't want them
 		 * floating about in memory - the physical journal device may
 		 * hotswapped, and it breaks the `ro-after' testing code.
 		 */
-		sync_blockdev(sbi->journal_bdev);
-		invalidate_bdev(sbi->journal_bdev);
+		sync_blockdev(sbi->s_journal_bdev);
+		invalidate_bdev(sbi->s_journal_bdev);
 		ext4_blkdev_remove(sbi);
 	}
 
@@ -3765,7 +3765,7 @@ int ext4_calculate_overhead(struct super_block *sb)
 	 * Add the internal journal blocks whether the journal has been
 	 * loaded or not
 	 */
-	if (sbi->s_journal && !sbi->journal_bdev)
+	if (sbi->s_journal && !sbi->s_journal_bdev)
 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
 		/* j_inum for internal journal is non-zero */
@@ -5126,7 +5126,7 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
 			be32_to_cpu(journal->j_superblock->s_nr_users));
 		goto out_journal;
 	}
-	EXT4_SB(sb)->journal_bdev = bdev;
+	EXT4_SB(sb)->s_journal_bdev = bdev;
 	ext4_init_journal_params(sb, journal);
 	return journal;