Commit ede7dc7f authored by Harshad Shirwadkar's avatar Harshad Shirwadkar Committed by Theodore Ts'o
Browse files

jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufs 



The on-disk superblock field sb->s_maxlen represents the total size of
the journal including the fast commit area and is no more the max
number of blocks available for a transaction. The maximum number of
blocks available to a transaction is reduced by the number of fast
commit blocks. So, this patch renames j_maxlen to j_total_len to
better represent its intent. Also, it adds a function to calculate max
number of bufs available for a transaction.

Suggested-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarHarshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-6-harshadshirwadkar@gmail.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent a80f7fcf

fs/ext4/fsmap.c

+1 −1
Original line number Diff line number Diff line
@@ -280,7 +280,7 @@ static int ext4_getfsmap_logdev(struct super_block *sb, struct ext4_fsmap *keys, 


	/* Fabricate an rmap entry for the external log device. */

	irec.fmr_physical = journal->j_blk_offset;

	irec.fmr_length = journal->j_maxlen;

	irec.fmr_length = journal->j_total_len;

	irec.fmr_owner = EXT4_FMR_OWN_LOG;

	irec.fmr_flags = 0;

fs/ext4/super.c

+1 −1
Original line number Diff line number Diff line
@@ -3976,7 +3976,7 @@ int ext4_calculate_overhead(struct super_block *sb) 
	 * loaded or not

	 */

	if (sbi->s_journal && !sbi->s_journal_bdev)

		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);

		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 */

		j_inode = ext4_get_journal_inode(sb, j_inum);

fs/jbd2/commit.c

+1 −1
Original line number Diff line number Diff line
@@ -801,7 +801,7 @@ start_journal_io: 
		if (first_block < journal->j_tail)

			freed += journal->j_last - journal->j_first;

		/* Update tail only if we free significant amount of space */

		if (freed < journal->j_maxlen / 4)

		if (freed < jbd2_journal_get_max_txn_bufs(journal))

			update_tail = 0;

	}

	J_ASSERT(commit_transaction->t_state == T_COMMIT);

fs/jbd2/journal.c

+6 −6
Original line number Diff line number Diff line
@@ -1348,7 +1348,7 @@ static journal_t *journal_init_common(struct block_device *bdev, 
	journal->j_dev = bdev;

	journal->j_fs_dev = fs_dev;

	journal->j_blk_offset = start;

	journal->j_maxlen = len;

	journal->j_total_len = len;

	/* We need enough buffers to write out full descriptor block. */

	n = journal->j_blocksize / jbd2_min_tag_size();

	journal->j_wbufsize = n;
@@ -1531,7 +1531,7 @@ static int journal_reset(journal_t *journal) 
	journal->j_commit_sequence = journal->j_transaction_sequence - 1;

	journal->j_commit_request = journal->j_commit_sequence;



	journal->j_max_transaction_buffers = journal->j_maxlen / 4;

	journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal);



	/*

	 * As a special case, if the on-disk copy is already marked as needing
@@ -1792,15 +1792,15 @@ static int journal_get_superblock(journal_t *journal) 
		goto out;

	}



	if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)

		journal->j_maxlen = be32_to_cpu(sb->s_maxlen);

	else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {

	if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)

		journal->j_total_len = be32_to_cpu(sb->s_maxlen);

	else 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_maxlen) {

	    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));

fs/jbd2/recovery.c

+3 −3
Original line number Diff line number Diff line
@@ -74,8 +74,8 @@ static int do_readahead(journal_t *journal, unsigned int start) 


	/* Do up to 128K of readahead */

	max = start + (128 * 1024 / journal->j_blocksize);

	if (max > journal->j_maxlen)

		max = journal->j_maxlen;

	if (max > journal->j_total_len)

		max = journal->j_total_len;



	/* Do the readahead itself.  We'll submit MAXBUF buffer_heads at

	 * a time to the block device IO layer. */
@@ -134,7 +134,7 @@ static int jread(struct buffer_head **bhp, journal_t *journal, 


	*bhp = NULL;



	if (offset >= journal->j_maxlen) {

	if (offset >= journal->j_total_len) {

		printk(KERN_ERR "JBD2: corrupted journal superblock\n");

		return -EFSCORRUPTED;

	}

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