Re: [PATCH 12/12] ext4: ext4_get_{dev}_journal return proper error value

Jan Kara
2023-08-03T16:19:11Z

On Tue 04-07-23 21:42:33, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
>
> ext4_get_journal() and ext4_get_dev_journal() return NULL if they failed
> to init journal, making them return proper error value instead, also
> rename them to ext4_open_{inode,dev}_journal().
>
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/super.c | 51 +++++++++++++++++++++++++++++--------------------
> 1 file changed, 30 insertions(+), 21 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 25ae536a370f..ae8a964e493d 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -5752,18 +5752,18 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
> journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
> if (IS_ERR(journal_inode)) {
> ext4_msg(sb, KERN_ERR, "no journal found");
> - return NULL;
> + return ERR_CAST(journal_inode);
> }
> if (!journal_inode->i_nlink) {
> make_bad_inode(journal_inode);
> iput(journal_inode);
> ext4_msg(sb, KERN_ERR, "journal inode is deleted");
> - return NULL;
> + return ERR_PTR(-EFSCORRUPTED);
> }
> if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
> ext4_msg(sb, KERN_ERR, "invalid journal inode");
> iput(journal_inode);
> - return NULL;
> + return ERR_PTR(-EFSCORRUPTED);
> }
>
> ext4_debug("Journal inode found at %p: %lld bytes\n",
> @@ -5793,21 +5793,21 @@ static int ext4_journal_bmap(journal_t *journal, sector_t *block)
> return 0;
> }
>
> -static journal_t *ext4_get_journal(struct super_block *sb,
> - unsigned int journal_inum)
> +static journal_t *ext4_open_inode_journal(struct super_block *sb,
> + unsigned int journal_inum)
> {
> struct inode *journal_inode;
> journal_t *journal;
>
> journal_inode = ext4_get_journal_inode(sb, journal_inum);
> - if (!journal_inode)
> - return NULL;
> + if (IS_ERR(journal_inode))
> + return ERR_CAST(journal_inode);
>
> journal = jbd2_journal_init_inode(journal_inode);
> if (IS_ERR(journal)) {
> ext4_msg(sb, KERN_ERR, "Could not load journal inode");
> iput(journal_inode);
> - return NULL;
> + return ERR_CAST(journal);
> }
> journal->j_private = sb;
> journal->j_bmap = ext4_journal_bmap;
> @@ -5825,6 +5825,7 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> ext4_fsblk_t sb_block;
> unsigned long offset;
> struct ext4_super_block *es;
> + int errno;
>
> bdev = blkdev_get_by_dev(j_dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
> &ext4_holder_ops);
> @@ -5832,7 +5833,7 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> 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 NULL;
> + return ERR_CAST(bdev);
> }
>
> blocksize = sb->s_blocksize;
> @@ -5840,6 +5841,7 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> if (blocksize < hblock) {
> ext4_msg(sb, KERN_ERR,
> "blocksize too small for journal device");
> + errno = -EINVAL;
> goto out_bdev;
> }
>
> @@ -5850,6 +5852,7 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> if (!bh) {
> ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
> "external journal");
> + errno = -EINVAL;
> goto out_bdev;
> }
>
> @@ -5858,6 +5861,7 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> !(le32_to_cpu(es->s_feature_incompat) &
> EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
> ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
> + errno = -EFSCORRUPTED;
> goto out_bh;
> }
>
> @@ -5865,11 +5869,13 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
> es->s_checksum != ext4_superblock_csum(sb, es)) {
> ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
> + errno = -EFSCORRUPTED;
> goto out_bh;
> }
>
> if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
> ext4_msg(sb, KERN_ERR, "journal UUID does not match");
> + errno = -EFSCORRUPTED;
> goto out_bh;
> }
>
> @@ -5882,31 +5888,34 @@ static struct block_device *ext4_get_journal_dev(struct super_block *sb,
> brelse(bh);
> out_bdev:
> blkdev_put(bdev, sb);
> - return NULL;
> + return ERR_PTR(errno);
> }
>
> -static journal_t *ext4_get_dev_journal(struct super_block *sb,
> - dev_t j_dev)
> +static journal_t *ext4_open_dev_journal(struct super_block *sb,
> + dev_t j_dev)
> {
> journal_t *journal;
> ext4_fsblk_t j_start;
> ext4_fsblk_t j_len;
> struct block_device *journal_bdev;
> + int errno = 0;
>
> journal_bdev = ext4_get_journal_dev(sb, j_dev, &j_start, &j_len);
> - if (!journal_bdev)
> - return NULL;
> + if (IS_ERR(journal_bdev))
> + return ERR_CAST(journal_bdev);
>
> journal = jbd2_journal_init_dev(journal_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");
> + errno = PTR_ERR(journal);
> goto out_bdev;
> }
> if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
> ext4_msg(sb, KERN_ERR, "External journal has more than one "
> "user (unsupported) - %d",
> be32_to_cpu(journal->j_superblock->s_nr_users));
> + errno = -EINVAL;
> goto out_journal;
> }
> journal->j_private = sb;
> @@ -5918,7 +5927,7 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
> jbd2_journal_destroy(journal);
> out_bdev:
> blkdev_put(journal_bdev, sb);
> - return NULL;
> + return ERR_PTR(errno);
> }
>
> static int ext4_load_journal(struct super_block *sb,
> @@ -5950,13 +5959,13 @@ static int ext4_load_journal(struct super_block *sb,
> }
>
> if (journal_inum) {
> - journal = ext4_get_journal(sb, journal_inum);
> - if (!journal)
> - return -EINVAL;
> + journal = ext4_open_inode_journal(sb, journal_inum);
> + if (IS_ERR(journal))
> + return PTR_ERR(journal);
> } else {
> - journal = ext4_get_dev_journal(sb, journal_dev);
> - if (!journal)
> - return -EINVAL;
> + journal = ext4_open_dev_journal(sb, journal_dev);
> + if (IS_ERR(journal))
> + return PTR_ERR(journal);
> }
>
> journal_dev_ro = bdev_read_only(journal->j_dev);
> --
> 2.39.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR