[PATCH 06/12] jbd2: cleanup load_superblock()

Zhang Yi
2023-07-04T13:44:15Z

From: Zhang Yi <yi.zhang@huawei.com>

Rename load_superblock() to journal_load_superblock(), move getting and
reading superblock from journal_init_common() and
journal_get_superblock() to this function, and also rename
journal_get_superblock() to journal_check_superblock(), make it a pure
check helper to check superblock validity from disk.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
fs/jbd2/journal.c | 95 +++++++++++++++++++++--------------------------
1 file changed, 43 insertions(+), 52 deletions(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 46ab47b4439e..efdb8db3c06e 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1340,46 +1340,33 @@ static void journal_fail_superblock(journal_t *journal)
journal->j_sb_buffer = NULL;
}

-/*
- * Read the superblock for a given journal, performing initial
+/**
+ * journal_check_superblock()
+ * @journal: journal to act on.
+ *
+ * Check the superblock for a given journal, performing initial
* validation of the format.
*/
-static int journal_get_superblock(journal_t *journal)
+static int journal_check_superblock(journal_t *journal)
{
- struct buffer_head *bh;
- journal_superblock_t *sb;
- int err;
-
- bh = journal->j_sb_buffer;
-
- J_ASSERT(bh != NULL);
-
- err = bh_read(bh, 0);
- if (err < 0) {
- printk(KERN_ERR
- "JBD2: IO error reading journal superblock\n");
- goto out;
- }
-
- sb = journal->j_superblock;
-
- err = -EINVAL;
+ journal_superblock_t *sb = journal->j_superblock;
+ int err = -EINVAL;

if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
- goto out;
+ return err;
}

if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 &&
be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) {
printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
- goto out;
+ return err;
}

if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
printk(KERN_WARNING "JBD2: journal file too short\n");
- goto out;
+ return err;
}

if (be32_to_cpu(sb->s_first) == 0 ||
@@ -1387,7 +1374,7 @@ static int journal_get_superblock(journal_t *journal)
printk(KERN_WARNING
"JBD2: Invalid start block of journal: %u\n",
be32_to_cpu(sb->s_first));
- goto out;
+ return err;
}

/*
@@ -1402,7 +1389,7 @@ static int journal_get_superblock(journal_t *journal)
(sb->s_feature_incompat &
~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
printk(KERN_WARNING "JBD2: Unrecognised features on journal\n");
- goto out;
+ return err;
}

if (jbd2_has_feature_csum2(journal) &&
@@ -1410,7 +1397,7 @@ static int journal_get_superblock(journal_t *journal)
/* Can't have checksum v2 and v3 at the same time! */
printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
"at the same time!\n");
- goto out;
+ return err;
}

if (jbd2_journal_has_csum_v2or3_feature(journal) &&
@@ -1418,14 +1405,14 @@ static int journal_get_superblock(journal_t *journal)
/* Can't have checksum v1 and v2 on at the same time! */
printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
"at the same time!\n");
- goto out;
+ return err;
}

/* Load the checksum driver */
if (jbd2_journal_has_csum_v2or3_feature(journal)) {
if (sb->s_checksum_type != JBD2_CRC32C_CHKSUM) {
printk(KERN_ERR "JBD2: Unknown checksum type\n");
- goto out;
+ return err;
}

journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
@@ -1433,20 +1420,17 @@ static int journal_get_superblock(journal_t *journal)
printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
err = PTR_ERR(journal->j_chksum_driver);
journal->j_chksum_driver = NULL;
- goto out;
+ return err;
}
/* Check superblock checksum */
if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
printk(KERN_ERR "JBD2: journal checksum error\n");
err = -EFSBADCRC;
- goto out;
+ return err;
}
}
- return 0;

-out:
- journal_fail_superblock(journal);
- return err;
+ return 0;
}

static int journal_revoke_records_per_block(journal_t *journal)
@@ -1464,21 +1448,38 @@ static int journal_revoke_records_per_block(journal_t *journal)
return space / record_size;
}

-/*
+/**
+ * journal_load_superblock()
+ * @journal: journal to act on.
+ *
* Load the on-disk journal superblock and read the key fields into the
* journal_t.
*/
-static int load_superblock(journal_t *journal)
+static int journal_load_superblock(journal_t *journal)
{
int err;
+ struct buffer_head *bh;
journal_superblock_t *sb;
int num_fc_blocks;

- err = journal_get_superblock(journal);
- if (err)
- return err;
+ bh = getblk_unmovable(journal->j_dev, journal->j_blk_offset,
+ journal->j_blocksize);
+ if (bh)
+ err = bh_read(bh, 0);
+ if (!bh || err < 0) {
+ pr_err("%s: Cannot read journal superblock\n", __func__);
+ brelse(bh);
+ return -EIO;
+ }

- sb = journal->j_superblock;
+ journal->j_sb_buffer = bh;
+ sb = (journal_superblock_t *)bh->b_data;
+ journal->j_superblock = sb;
+ err = journal_check_superblock(journal);
+ if (err) {
+ journal_fail_superblock(journal);
+ return err;
+ }

journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
journal->j_tail = be32_to_cpu(sb->s_start);
@@ -1524,7 +1525,6 @@ static journal_t *journal_init_common(struct block_device *bdev,
static struct lock_class_key jbd2_trans_commit_key;
journal_t *journal;
int err;
- struct buffer_head *bh;
int n;

journal = kzalloc(sizeof(*journal), GFP_KERNEL);
@@ -1577,16 +1577,7 @@ static journal_t *journal_init_common(struct block_device *bdev,
if (!journal->j_wbuf)
goto err_cleanup;

- bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize);
- if (!bh) {
- pr_err("%s: Cannot get buffer for journal superblock\n",
- __func__);
- goto err_cleanup;
- }
- journal->j_sb_buffer = bh;
- journal->j_superblock = (journal_superblock_t *)bh->b_data;
-
- err = load_superblock(journal);
+ err = journal_load_superblock(journal);
if (err)
goto err_cleanup;

--
2.39.2