diff options
Diffstat (limited to 'fs/jbd2')
| -rw-r--r-- | fs/jbd2/journal.c | 119 |
1 files changed, 116 insertions, 3 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 2dc944442802..3a2ed60ea8b7 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1686,6 +1686,110 @@ static void jbd2_mark_journal_empty(journal_t *journal, int write_op) write_unlock(&journal->j_state_lock); } +/** + * __jbd2_journal_erase() - Discard or zeroout journal blocks (excluding superblock) + * @journal: The journal to erase. + * @flags: A discard/zeroout request is sent for each physically contigous + * region of the journal. Either JBD2_JOURNAL_FLUSH_DISCARD or + * JBD2_JOURNAL_FLUSH_ZEROOUT must be set to determine which operation + * to perform. + * + * Note: JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. Zeroes + * will be explicitly written if no hardware offload is available, see + * blkdev_issue_zeroout for more details. + */ +static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) +{ + int err = 0; + unsigned long block, log_offset; /* logical */ + unsigned long long phys_block, block_start, block_stop; /* physical */ + loff_t byte_start, byte_stop, byte_count; + struct request_queue *q = bdev_get_queue(journal->j_dev); + + /* flags must be set to either discard or zeroout */ + if ((flags & ~JBD2_JOURNAL_FLUSH_VALID) || !flags || + ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && + (flags & JBD2_JOURNAL_FLUSH_ZEROOUT))) + return -EINVAL; + + if (!q) + return -ENXIO; + + if ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && !blk_queue_discard(q)) + return -EOPNOTSUPP; + + /* + * lookup block mapping and issue discard/zeroout for each + * contiguous region + */ + log_offset = be32_to_cpu(journal->j_superblock->s_first); + block_start = ~0ULL; + for (block = log_offset; block < journal->j_total_len; block++) { + err = jbd2_journal_bmap(journal, block, &phys_block); + if (err) { + pr_err("JBD2: bad block at offset %lu", block); + return err; + } + + if (block_start == ~0ULL) { + block_start = phys_block; + block_stop = block_start - 1; + } + + /* + * last block not contiguous with current block, + * process last contiguous region and return to this block on + * next loop + */ + if (phys_block != block_stop + 1) { + block--; + } else { + block_stop++; + /* + * if this isn't the last block of journal, + * no need to process now because next block may also + * be part of this contiguous region + */ + if (block != journal->j_total_len - 1) + continue; + } + + /* + * end of contiguous region or this is last block of journal, + * take care of the region + */ + byte_start = block_start * journal->j_blocksize; + byte_stop = block_stop * journal->j_blocksize; + byte_count = (block_stop - block_start + 1) * + journal->j_blocksize; + + truncate_inode_pages_range(journal->j_dev->bd_inode->i_mapping, + byte_start, byte_stop); + + if (flags & JBD2_JOURNAL_FLUSH_DISCARD) { + err = blkdev_issue_discard(journal->j_dev, + byte_start >> SECTOR_SHIFT, + byte_count >> SECTOR_SHIFT, + GFP_NOFS, 0); + } else if (flags & JBD2_JOURNAL_FLUSH_ZEROOUT) { + err = blkdev_issue_zeroout(journal->j_dev, + byte_start >> SECTOR_SHIFT, + byte_count >> SECTOR_SHIFT, + GFP_NOFS, 0); + } + + if (unlikely(err != 0)) { + pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu", + err, block_start, block_stop); + return err; + } + + /* reset start and stop after processing a region */ + block_start = ~0ULL; + } + + return blkdev_issue_flush(journal->j_dev); +} /** * jbd2_journal_update_sb_errno() - Update error in the journal. @@ -2246,13 +2350,18 @@ EXPORT_SYMBOL(jbd2_journal_clear_features); /** * jbd2_journal_flush() - Flush journal * @journal: Journal to act on. + * @flags: optional operation on the journal blocks after the flush (see below) * * Flush all data for a given journal to disk and empty the journal. * Filesystems can use this when remounting readonly to ensure that - * recovery does not need to happen on remount. + * recovery does not need to happen on remount. Optionally, a discard or zeroout + * can be issued on the journal blocks after flushing. + * + * flags: + * JBD2_JOURNAL_FLUSH_DISCARD: issues discards for the journal blocks + * JBD2_JOURNAL_FLUSH_ZEROOUT: issues zeroouts for the journal blocks */ - -int jbd2_journal_flush(journal_t *journal) +int jbd2_journal_flush(journal_t *journal, unsigned int flags) { int err = 0; transaction_t *transaction = NULL; @@ -2306,6 +2415,10 @@ int jbd2_journal_flush(journal_t *journal) * commits of data to the journal will restore the current * s_start value. */ jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA); + + if (flags) + err = __jbd2_journal_erase(journal, flags); + mutex_unlock(&journal->j_checkpoint_mutex); write_lock(&journal->j_state_lock); J_ASSERT(!journal->j_running_transaction); |