ext4: Convert to bdev_open_by_dev()

Convert ext4 to use bdev_open_by_dev() and pass the handle around.

CC: [e-mail]
CC: Ted Tso <[e-mail]>
Acked-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Christian Brauner <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Christian Brauner <[e-mail]>

fs/ext4/ext4.h

···
 	unsigned long s_commit_interval;
 	u32 s_max_batch_time;
 	u32 s_min_batch_time;
-	struct block_device *s_journal_bdev;
+	struct bdev_handle *s_journal_bdev_handle;
 #ifdef CONFIG_QUOTA
 	/* Names of quota files with journalled quota */
 	char __rcu *s_qf_names[EXT4_MAXQUOTAS];

fs/ext4/fsmap.c

···
 	if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
 	    fm->fmr_device == new_encode_dev(sb->s_bdev->bd_dev))
 		return true;
-	if (EXT4_SB(sb)->s_journal_bdev &&
-	    fm->fmr_device == new_encode_dev(EXT4_SB(sb)->s_journal_bdev->bd_dev))
+	if (EXT4_SB(sb)->s_journal_bdev_handle &&
+	    fm->fmr_device ==
+	    new_encode_dev(EXT4_SB(sb)->s_journal_bdev_handle->bdev->bd_dev))
 		return true;
 	return false;
 }
···
 	memset(handlers, 0, sizeof(handlers));
 	handlers[0].gfd_dev = new_encode_dev(sb->s_bdev->bd_dev);
 	handlers[0].gfd_fn = ext4_getfsmap_datadev;
-	if (EXT4_SB(sb)->s_journal_bdev) {
+	if (EXT4_SB(sb)->s_journal_bdev_handle) {
 		handlers[1].gfd_dev = new_encode_dev(
-				EXT4_SB(sb)->s_journal_bdev->bd_dev);
+			EXT4_SB(sb)->s_journal_bdev_handle->bdev->bd_dev);
 		handlers[1].gfd_fn = ext4_getfsmap_logdev;
 	}
 

fs/ext4/super.c

···
 
 	sync_blockdev(sb->s_bdev);
 	invalidate_bdev(sb->s_bdev);
-	if (sbi->s_journal_bdev) {
+	if (sbi->s_journal_bdev_handle) {
 		/*
 		 * 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->s_journal_bdev);
-		invalidate_bdev(sbi->s_journal_bdev);
+		sync_blockdev(sbi->s_journal_bdev_handle->bdev);
+		invalidate_bdev(sbi->s_journal_bdev_handle->bdev);
 	}
 
 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
···
 	 * Add the internal journal blocks whether the journal has been
 	 * loaded or not
 	 */
-	if (sbi->s_journal && !sbi->s_journal_bdev)
+	if (sbi->s_journal && !sbi->s_journal_bdev_handle)
 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
 		/* j_inum for internal journal is non-zero */
···
 #endif
 	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
 	brelse(sbi->s_sbh);
-	if (sbi->s_journal_bdev) {
-		invalidate_bdev(sbi->s_journal_bdev);
-		blkdev_put(sbi->s_journal_bdev, sb);
+	if (sbi->s_journal_bdev_handle) {
+		invalidate_bdev(sbi->s_journal_bdev_handle->bdev);
+		bdev_release(sbi->s_journal_bdev_handle);
 	}
 out_fail:
 	invalidate_bdev(sb->s_bdev);
···
 	return journal;
 }
 
-static struct block_device *ext4_get_journal_blkdev(struct super_block *sb,
+static struct bdev_handle *ext4_get_journal_blkdev(struct super_block *sb,
 					dev_t j_dev, ext4_fsblk_t *j_start,
 					ext4_fsblk_t *j_len)
 {
 	struct buffer_head *bh;
 	struct block_device *bdev;
+	struct bdev_handle *bdev_handle;
 	int hblock, blocksize;
 	ext4_fsblk_t sb_block;
 	unsigned long offset;
···
 
 	/* see get_tree_bdev why this is needed and safe */
 	up_write(&sb->s_umount);
-	bdev = blkdev_get_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
-				 &fs_holder_ops);
+	bdev_handle = bdev_open_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE,
+				       sb, &fs_holder_ops);
 	down_write(&sb->s_umount);
-	if (IS_ERR(bdev)) {
+	if (IS_ERR(bdev_handle)) {
 		ext4_msg(sb, KERN_ERR,
 			 "failed to open journal device unknown-block(%u,%u) %ld",
-			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev));
-		return ERR_CAST(bdev);
+			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_handle));
+		return bdev_handle;
 	}
 
+	bdev = bdev_handle->bdev;
 	blocksize = sb->s_blocksize;
 	hblock = bdev_logical_block_size(bdev);
 	if (blocksize < hblock) {
···
 	*j_start = sb_block + 1;
 	*j_len = ext4_blocks_count(es);
 	brelse(bh);
-	return bdev;
+	return bdev_handle;
 
 out_bh:
 	brelse(bh);
 out_bdev:
-	blkdev_put(bdev, sb);
+	bdev_release(bdev_handle);
 	return ERR_PTR(errno);
 }
 
···
 	journal_t *journal;
 	ext4_fsblk_t j_start;
 	ext4_fsblk_t j_len;
-	struct block_device *journal_bdev;
+	struct bdev_handle *bdev_handle;
 	int errno = 0;
 
-	journal_bdev = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
-	if (IS_ERR(journal_bdev))
-		return ERR_CAST(journal_bdev);
+	bdev_handle = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
+	if (IS_ERR(bdev_handle))
+		return ERR_CAST(bdev_handle);
 
-	journal = jbd2_journal_init_dev(journal_bdev, sb->s_bdev, j_start,
+	journal = jbd2_journal_init_dev(bdev_handle->bdev, sb->s_bdev, j_start,
 					j_len, sb->s_blocksize);
 	if (IS_ERR(journal)) {
 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
···
 		goto out_journal;
 	}
 	journal->j_private = sb;
-	EXT4_SB(sb)->s_journal_bdev = journal_bdev;
+	EXT4_SB(sb)->s_journal_bdev_handle = bdev_handle;
 	ext4_init_journal_params(sb, journal);
 	return journal;
 
 out_journal:
 	jbd2_journal_destroy(journal);
 out_bdev:
-	blkdev_put(journal_bdev, sb);
+	bdev_release(bdev_handle);
 	return ERR_PTR(errno);
 }
 
···
 static void ext4_kill_sb(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	struct block_device *journal_bdev = sbi ? sbi->s_journal_bdev : NULL;
+	struct bdev_handle *handle = sbi ? sbi->s_journal_bdev_handle : NULL;
 
 	kill_block_super(sb);
 
-	if (journal_bdev)
-		blkdev_put(journal_bdev, sb);
+	if (handle)
+		bdev_release(handle);
 }
 
 static struct file_system_type ext4_fs_type = {