Re: [PATCH 01/12] jbd2: move load_superblock() dependent functions

Jan Kara
2023-08-03T14:09:12Z

On Tue 04-07-23 21:42:22, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
>
> Moving load_superblock() dependent functions before
> journal_init_common(), just preparing for moving the call to
> load_superblock() from jbd2_journal_load() and jbd2_journal_wipe() to
> journal_init_common(), no functional changes.
>
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

I'd just slightly rephrase the changelog:

Move load_superblock() declaration and the functions it calls before
journal_init_common(). This is a preparation for moving a call to
load_superblock() from jbd2_journal_load() and jbd2_journal_wipe() to
journal_init_common(). No functional changes.

Otherwise the patch looks good. Feel free to add:

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

Honza

> ---
> fs/jbd2/journal.c | 337 +++++++++++++++++++++++-----------------------
> 1 file changed, 168 insertions(+), 169 deletions(-)
>
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index fbce16fedaa4..48c44c7fccf4 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1336,6 +1336,174 @@ static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink,
> return count;
> }
>
> +/*
> + * If the journal init or create aborts, we need to mark the journal
> + * superblock as being NULL to prevent the journal destroy from writing
> + * back a bogus superblock.
> + */
> +static void journal_fail_superblock(journal_t *journal)
> +{
> + struct buffer_head *bh = journal->j_sb_buffer;
> + brelse(bh);
> + journal->j_sb_buffer = NULL;
> +}
> +
> +/*
> + * Read the superblock for a given journal, performing initial
> + * validation of the format.
> + */
> +static int journal_get_superblock(journal_t *journal)
> +{
> + struct buffer_head *bh;
> + journal_superblock_t *sb;
> + int err;
> +
> + bh = journal->j_sb_buffer;
> +
> + J_ASSERT(bh != NULL);
> + if (buffer_verified(bh))
> + return 0;
> +
> + 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;
> +
> + 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;
> + }
> +
> + 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;
> + }
> +
> + if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
> + printk(KERN_WARNING "JBD2: journal file too short\n");
> + goto out;
> + }
> +
> + if (be32_to_cpu(sb->s_first) == 0 ||
> + be32_to_cpu(sb->s_first) >= journal->j_total_len) {
> + printk(KERN_WARNING
> + "JBD2: Invalid start block of journal: %u\n",
> + be32_to_cpu(sb->s_first));
> + goto out;
> + }
> +
> + if (jbd2_has_feature_csum2(journal) &&
> + jbd2_has_feature_csum3(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;
> + }
> +
> + if (jbd2_journal_has_csum_v2or3_feature(journal) &&
> + jbd2_has_feature_checksum(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;
> + }
> +
> + if (!jbd2_verify_csum_type(journal, sb)) {
> + printk(KERN_ERR "JBD2: Unknown checksum type\n");
> + goto out;
> + }
> +
> + /* Load the checksum driver */
> + if (jbd2_journal_has_csum_v2or3_feature(journal)) {
> + journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
> + if (IS_ERR(journal->j_chksum_driver)) {
> + printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
> + err = PTR_ERR(journal->j_chksum_driver);
> + journal->j_chksum_driver = NULL;
> + goto out;
> + }
> + /* Check superblock checksum */
> + if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
> + printk(KERN_ERR "JBD2: journal checksum error\n");
> + err = -EFSBADCRC;
> + goto out;
> + }
> + }
> + set_buffer_verified(bh);
> + return 0;
> +
> +out:
> + journal_fail_superblock(journal);
> + return err;
> +}
> +
> +static int journal_revoke_records_per_block(journal_t *journal)
> +{
> + int record_size;
> + int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t);
> +
> + if (jbd2_has_feature_64bit(journal))
> + record_size = 8;
> + else
> + record_size = 4;
> +
> + if (jbd2_journal_has_csum_v2or3(journal))
> + space -= sizeof(struct jbd2_journal_block_tail);
> + return space / record_size;
> +}
> +
> +/*
> + * Load the on-disk journal superblock and read the key fields into the
> + * journal_t.
> + */
> +static int load_superblock(journal_t *journal)
> +{
> + int err;
> + journal_superblock_t *sb;
> + int num_fc_blocks;
> +
> + err = journal_get_superblock(journal);
> + if (err)
> + return err;
> +
> + sb = journal->j_superblock;
> +
> + journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
> + journal->j_tail = be32_to_cpu(sb->s_start);
> + journal->j_first = be32_to_cpu(sb->s_first);
> + journal->j_errno = be32_to_cpu(sb->s_errno);
> + journal->j_last = be32_to_cpu(sb->s_maxlen);
> +
> + if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
> + journal->j_total_len = be32_to_cpu(sb->s_maxlen);
> + /* Precompute checksum seed for all metadata */
> + if (jbd2_journal_has_csum_v2or3(journal))
> + journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
> + sizeof(sb->s_uuid));
> + journal->j_revoke_records_per_block =
> + journal_revoke_records_per_block(journal);
> +
> + if (jbd2_has_feature_fast_commit(journal)) {
> + journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
> + num_fc_blocks = jbd2_journal_get_num_fc_blks(sb);
> + if (journal->j_last - num_fc_blocks >= JBD2_MIN_JOURNAL_BLOCKS)
> + journal->j_last = journal->j_fc_last - num_fc_blocks;
> + journal->j_fc_first = journal->j_last + 1;
> + journal->j_fc_off = 0;
> + }
> +
> + return 0;
> +}
> +
> +
> /*
> * Management for journal control blocks: functions to create and
> * destroy journal_t structures, and to initialise and read existing
> @@ -1521,18 +1689,6 @@ journal_t *jbd2_journal_init_inode(struct inode *inode)
> return journal;
> }
>
> -/*
> - * If the journal init or create aborts, we need to mark the journal
> - * superblock as being NULL to prevent the journal destroy from writing
> - * back a bogus superblock.
> - */
> -static void journal_fail_superblock(journal_t *journal)
> -{
> - struct buffer_head *bh = journal->j_sb_buffer;
> - brelse(bh);
> - journal->j_sb_buffer = NULL;
> -}
> -
> /*
> * Given a journal_t structure, initialise the various fields for
> * startup of a new journaling session. We use this both when creating
> @@ -1889,163 +2045,6 @@ void jbd2_journal_update_sb_errno(journal_t *journal)
> }
> EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
>
> -static int journal_revoke_records_per_block(journal_t *journal)
> -{
> - int record_size;
> - int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t);
> -
> - if (jbd2_has_feature_64bit(journal))
> - record_size = 8;
> - else
> - record_size = 4;
> -
> - if (jbd2_journal_has_csum_v2or3(journal))
> - space -= sizeof(struct jbd2_journal_block_tail);
> - return space / record_size;
> -}
> -
> -/*
> - * Read the superblock for a given journal, performing initial
> - * validation of the format.
> - */
> -static int journal_get_superblock(journal_t *journal)
> -{
> - struct buffer_head *bh;
> - journal_superblock_t *sb;
> - int err;
> -
> - bh = journal->j_sb_buffer;
> -
> - J_ASSERT(bh != NULL);
> - if (buffer_verified(bh))
> - return 0;
> -
> - 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;
> -
> - 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;
> - }
> -
> - 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;
> - }
> -
> - if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
> - printk(KERN_WARNING "JBD2: journal file too short\n");
> - goto out;
> - }
> -
> - if (be32_to_cpu(sb->s_first) == 0 ||
> - be32_to_cpu(sb->s_first) >= journal->j_total_len) {
> - printk(KERN_WARNING
> - "JBD2: Invalid start block of journal: %u\n",
> - be32_to_cpu(sb->s_first));
> - goto out;
> - }
> -
> - if (jbd2_has_feature_csum2(journal) &&
> - jbd2_has_feature_csum3(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;
> - }
> -
> - if (jbd2_journal_has_csum_v2or3_feature(journal) &&
> - jbd2_has_feature_checksum(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;
> - }
> -
> - if (!jbd2_verify_csum_type(journal, sb)) {
> - printk(KERN_ERR "JBD2: Unknown checksum type\n");
> - goto out;
> - }
> -
> - /* Load the checksum driver */
> - if (jbd2_journal_has_csum_v2or3_feature(journal)) {
> - journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
> - if (IS_ERR(journal->j_chksum_driver)) {
> - printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
> - err = PTR_ERR(journal->j_chksum_driver);
> - journal->j_chksum_driver = NULL;
> - goto out;
> - }
> - /* Check superblock checksum */
> - if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
> - printk(KERN_ERR "JBD2: journal checksum error\n");
> - err = -EFSBADCRC;
> - goto out;
> - }
> - }
> - set_buffer_verified(bh);
> - return 0;
> -
> -out:
> - journal_fail_superblock(journal);
> - return err;
> -}
> -
> -/*
> - * Load the on-disk journal superblock and read the key fields into the
> - * journal_t.
> - */
> -
> -static int load_superblock(journal_t *journal)
> -{
> - int err;
> - journal_superblock_t *sb;
> - int num_fc_blocks;
> -
> - err = journal_get_superblock(journal);
> - if (err)
> - return err;
> -
> - sb = journal->j_superblock;
> -
> - journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
> - journal->j_tail = be32_to_cpu(sb->s_start);
> - journal->j_first = be32_to_cpu(sb->s_first);
> - journal->j_errno = be32_to_cpu(sb->s_errno);
> - journal->j_last = be32_to_cpu(sb->s_maxlen);
> -
> - if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
> - journal->j_total_len = be32_to_cpu(sb->s_maxlen);
> - /* Precompute checksum seed for all metadata */
> - if (jbd2_journal_has_csum_v2or3(journal))
> - journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
> - sizeof(sb->s_uuid));
> - journal->j_revoke_records_per_block =
> - journal_revoke_records_per_block(journal);
> -
> - if (jbd2_has_feature_fast_commit(journal)) {
> - journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
> - num_fc_blocks = jbd2_journal_get_num_fc_blks(sb);
> - if (journal->j_last - num_fc_blocks >= JBD2_MIN_JOURNAL_BLOCKS)
> - journal->j_last = journal->j_fc_last - num_fc_blocks;
> - journal->j_fc_first = journal->j_last + 1;
> - journal->j_fc_off = 0;
> - }
> -
> - return 0;
> -}
> -
> -
> /**
> * jbd2_journal_load() - Read journal from disk.
> * @journal: Journal to act on.
> --
> 2.39.2
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR