jbd2: cleanup load_superblock()

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>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230811063610.2980059-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 5d4744203e39193eeffeae6c543edd8bb95ccaab..89f9eb35323da4d58d4a43990f3416a804bf0b1a 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1341,45 +1341,29 @@ static void journal_fail_superblock(journal_t *journal)
 }
 
 /*
- * Read the superblock for a given journal, performing initial
+ * 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 +1371,7 @@ 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 +1386,7 @@ 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 +1394,7 @@ 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 +1402,14 @@ 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 +1417,17 @@ 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)
@@ -1468,17 +1449,31 @@ static int journal_revoke_records_per_block(journal_t *journal)
  * 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 +1519,6 @@ 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 +1571,7 @@ 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;