diff options
Diffstat (limited to 'fs/jbd2')
| -rw-r--r-- | fs/jbd2/commit.c | 198 | ||||
| -rw-r--r-- | fs/jbd2/journal.c | 26 | ||||
| -rw-r--r-- | fs/jbd2/recovery.c | 151 |
3 files changed, 318 insertions, 57 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 8749a86..da8d0eb 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -21,6 +21,7 @@ #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/jiffies.h> +#include <linux/crc32.h> /* * Default IO end handler for temporary BJ_IO buffer_heads. @@ -93,19 +94,23 @@ static int inverted_lock(journal_t *journal, struct buffer_head *bh) return 1; } -/* Done it all: now write the commit record. We should have +/* + * Done it all: now submit the commit record. We should have * cleaned up our previous buffers by now, so if we are in abort * mode we can now just skip the rest of the journal write * entirely. * * Returns 1 if the journal needs to be aborted or 0 on success */ -static int journal_write_commit_record(journal_t *journal, - transaction_t *commit_transaction) +static int journal_submit_commit_record(journal_t *journal, + transaction_t *commit_transaction, + struct buffer_head **cbh, + __u32 crc32_sum) { struct journal_head *descriptor; + struct commit_header *tmp; struct buffer_head *bh; - int i, ret; + int ret; int barrier_done = 0; if (is_journal_aborted(journal)) @@ -117,21 +122,33 @@ static int journal_write_commit_record(journal_t *journal, bh = jh2bh(descriptor); - /* AKPM: buglet - add `i' to tmp! */ - for (i = 0; i < bh->b_size; i += 512) { - journal_header_t *tmp = (journal_header_t*)bh->b_data; - tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); - tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK); - tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid); + tmp = (struct commit_header *)bh->b_data; + tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); + tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK); + tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid); + + if (JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_COMPAT_CHECKSUM)) { + tmp->h_chksum_type = JBD2_CRC32_CHKSUM; + tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE; + tmp->h_chksum[0] = cpu_to_be32(crc32_sum); } - JBUFFER_TRACE(descriptor, "write commit block"); + JBUFFER_TRACE(descriptor, "submit commit block"); + lock_buffer(bh); + set_buffer_dirty(bh); - if (journal->j_flags & JBD2_BARRIER) { + set_buffer_uptodate(bh); + bh->b_end_io = journal_end_buffer_io_sync; + + if (journal->j_flags & JBD2_BARRIER && + !JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) { set_buffer_ordered(bh); barrier_done = 1; } - ret = sync_dirty_buffer(bh); + ret = submit_bh(WRITE, bh); + /* is it possible for another commit to fail at roughly * the same time as this one? If so, we don't want to * trust the barrier flag in the super, but instead want @@ -152,14 +169,72 @@ static int journal_write_commit_record(journal_t *journal, clear_buffer_ordered(bh); set_buffer_uptodate(bh); set_buffer_dirty(bh); - ret = sync_dirty_buffer(bh); + ret = submit_bh(WRITE, bh); } - put_bh(bh); /* One for getblk() */ - jbd2_journal_put_journal_head(descriptor); + *cbh = bh; + return ret; +} + +/* + * This function along with journal_submit_commit_record + * allows to write the commit record asynchronously. + */ +static int journal_wait_on_commit_record(struct buffer_head *bh) +{ + int ret = 0; + + clear_buffer_dirty(bh); + wait_on_buffer(bh); - return (ret == -EIO); + if (unlikely(!buffer_uptodate(bh))) + ret = -EIO; + put_bh(bh); /* One for getblk() */ + jbd2_journal_put_journal_head(bh2jh(bh)); + + return ret; } +/* + * Wait for all submitted IO to complete. + */ +static int journal_wait_on_locked_list(journal_t *journal, + transaction_t *commit_transaction) +{ + int ret = 0; + struct journal_head *jh; + + while (commit_transaction->t_locked_list) { + struct buffer_head *bh; + + jh = commit_transaction->t_locked_list->b_tprev; + bh = jh2bh(jh); + get_bh(bh); + if (buffer_locked(bh)) { + spin_unlock(&journal->j_list_lock); + wait_on_buffer(bh); + if (unlikely(!buffer_uptodate(bh))) + ret = -EIO; + spin_lock(&journal->j_list_lock); + } + if (!inverted_lock(journal, bh)) { + put_bh(bh); + spin_lock(&journal->j_list_lock); + continue; + } + if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) { + __jbd2_journal_unfile_buffer(jh); + jbd_unlock_bh_state(bh); + jbd2_journal_remove_journal_head(bh); + put_bh(bh); + } else { + jbd_unlock_bh_state(bh); + } + put_bh(bh); + cond_resched_lock(&journal->j_list_lock); + } + return ret; + } + static void journal_do_submit_data(struct buffer_head **wbuf, int bufs) { int i; @@ -275,7 +350,21 @@ write_out_data: journal_do_submit_data(wbuf, bufs); } -static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag, +static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh) +{ + struct page *page = bh->b_page; + char *addr; + __u32 checksum; + + addr = kmap_atomic(page, KM_USER0); + checksum = crc32_be(crc32_sum, + (void *)(addr + offset_in_page(bh->b_data)), bh->b_size); + kunmap_atomic(addr, KM_USER0); + + return checksum; +} + +static void write_tag_block(int tag_bytes, journal_block_tag_t *tag, unsigned long long block) { tag->t_blocknr = cpu_to_be32(block & (u32)~0); @@ -307,6 +396,8 @@ void jbd2_journal_commit_transaction(journal_t *journal) int tag_flag; int i; int tag_bytes = journal_tag_bytes(journal); + struct buffer_head *cbh = NULL; /* For transactional checksums */ + __u32 crc32_sum = ~0; /* * First job: lock down the current transaction and wait for @@ -451,38 +542,15 @@ void jbd2_journal_commit_transaction(journal_t *journal) journal_submit_data_buffers(journal, commit_transaction); /* - * Wait for all previously submitted IO to complete. + * Wait for all previously submitted IO to complete if commit + * record is to be written synchronously. */ spin_lock(&journal->j_list_lock); - while (commit_transaction->t_locked_list) { - struct buffer_head *bh; + if (!JBD2_HAS_INCOMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) + err = journal_wait_on_locked_list(journal, + commit_transaction); - jh = commit_transaction->t_locked_list->b_tprev; - bh = jh2bh(jh); - get_bh(bh); - if (buffer_locked(bh)) { - spin_unlock(&journal->j_list_lock); - wait_on_buffer(bh); - if (unlikely(!buffer_uptodate(bh))) - err = -EIO; - spin_lock(&journal->j_list_lock); - } - if (!inverted_lock(journal, bh)) { - put_bh(bh); - spin_lock(&journal->j_list_lock); - continue; - } - if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) { - __jbd2_journal_unfile_buffer(jh); - jbd_unlock_bh_state(bh); - jbd2_journal_remove_journal_head(bh); - put_bh(bh); - } else { - jbd_unlock_bh_state(bh); - } - put_bh(bh); - cond_resched_lock(&journal->j_list_lock); - } spin_unlock(&journal->j_list_lock); if (err) @@ -656,6 +724,15 @@ void jbd2_journal_commit_transaction(journal_t *journal) start_journal_io: for (i = 0; i < bufs; i++) { struct buffer_head *bh = wbuf[i]; + /* + * Compute checksum. + */ + if (JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_COMPAT_CHECKSUM)) { + crc32_sum = + jbd2_checksum_data(crc32_sum, bh); + } + lock_buffer(bh); clear_buffer_dirty(bh); set_buffer_uptodate(bh); @@ -672,6 +749,23 @@ start_journal_io: } } + /* Done it all: now write the commit record asynchronously. */ + + if (JBD2_HAS_INCOMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) { + err = journal_submit_commit_record(journal, commit_transaction, + &cbh, crc32_sum); + if (err) + __jbd2_journal_abort_hard(journal); + + spin_lock(&journal->j_list_lock); + err = journal_wait_on_locked_list(journal, + commit_transaction); + spin_unlock(&journal->j_list_lock); + if (err) + __jbd2_journal_abort_hard(journal); + } + /* Lo and behold: we have just managed to send a transaction to the log. Before we can commit it, wait for the IO so far to complete. Control buffers being written are on the @@ -771,8 +865,14 @@ wait_for_iobuf: jbd_debug(3, "JBD: commit phase 6\n"); - if (journal_write_commit_record(journal, commit_transaction)) - err = -EIO; + if (!JBD2_HAS_INCOMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) { + err = journal_submit_commit_record(journal, commit_transaction, + &cbh, crc32_sum); + if (err) + __jbd2_journal_abort_hard(journal); + } + err = journal_wait_on_commit_record(cbh); if (err) jbd2_journal_abort(journal, err); diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 3667c91..59ba249 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1578,6 +1578,32 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat, return 1; } +/* + * jbd2_journal_clear_features () - Clear a given journal feature in the + * superblock + * @journal: Journal to act on. + * @compat: bitmask of compatible features + * @ro: bitmask of features that force read-only mount + * @incompat: bitmask of incompatible features + * + * Clear a given journal feature as present on the + * superblock. + */ +void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, + unsigned long ro, unsigned long incompat) +{ + journal_superblock_t *sb; + + jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", + compat, ro, incompat); + + sb = journal->j_superblock; + + sb->s_feature_compat &= ~cpu_to_be32(compat); + sb->s_feature_ro_compat &= ~cpu_to_be32(ro); + sb->s_feature_incompat &= ~cpu_to_be32(incompat); +} +EXPORT_SYMBOL(jbd2_journal_clear_features); /** * int jbd2_journal_update_format () - Update on-disk journal structure. diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index d0ce627..9216806 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -21,6 +21,7 @@ #include <linux/jbd2.h> #include <linux/errno.h> #include <linux/slab.h> +#include <linux/crc32.h> #endif /* @@ -316,6 +317,37 @@ static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag return block; } +/* + * calc_chksums calculates the checksums for the blocks described in the + * descriptor block. + */ +static int calc_chksums(journal_t *journal, struct buffer_head *bh, + unsigned long *next_log_block, __u32 *crc32_sum) +{ + int i, num_blks, err; + unsigned long io_block; + struct buffer_head *obh; + + num_blks = count_tags(journal, bh); + /* Calculate checksum of the descriptor block. */ + *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size); + + for (i = 0; i < num_blks; i++) { + io_block = (*next_log_block)++; + wrap(journal, *next_log_block); + err = jread(&obh, journal, io_block); + if (err) { + printk(KERN_ERR "JBD: IO error %d recovering block " + "%lu in log\n", err, io_block); + return 1; + } else { + *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data, + obh->b_size); + } + } + return 0; +} + static int do_one_pass(journal_t *journal, struct recovery_info *info, enum passtype pass) { @@ -328,6 +360,7 @@ static int do_one_pass(journal_t *journal, unsigned int sequence; int blocktype; int tag_bytes = journal_tag_bytes(journal); + __u32 crc32_sum = ~0; /* Transactional Checksums */ /* Precompute the maximum metadata descriptors in a descriptor block */ int MAX_BLOCKS_PER_DESC; @@ -419,12 +452,26 @@ static int do_one_pass(journal_t *journal, switch(blocktype) { case JBD2_DESCRIPTOR_BLOCK: /* If it is a valid descriptor block, replay it - * in pass REPLAY; otherwise, just skip over the - * blocks it describes. */ + * in pass REPLAY; if journal_checksums enabled, then + * calculate checksums in PASS_SCAN, otherwise, + * just skip over the blocks it describes. */ if (pass != PASS_REPLAY) { + if (pass == PASS_SCAN && + JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_COMPAT_CHECKSUM) && + !info->end_transaction) { + if (calc_chksums(journal, bh, + &next_log_block, + &crc32_sum)) { + put_bh(bh); + break; + } + put_bh(bh); + continue; + } next_log_block += count_tags(journal, bh); wrap(journal, next_log_block); - brelse(bh); + put_bh(bh); continue; } @@ -516,9 +563,96 @@ static int do_one_pass(journal_t *journal, continue; case JBD2_COMMIT_BLOCK: - /* Found an expected commit block: not much to - * do other than move on to the next sequence + /* How to differentiate between interrupted commit + * and journal corruption ? + * + * {nth transaction} + * Checksum Verification Failed + * | + * ____________________ + * | | + * async_commit sync_commit + * | | + * | GO TO NEXT "Journal Corruption" + * | TRANSACTION + * | + * {(n+1)th transanction} + * | + * _______|______________ + * | | + * Commit block found Commit block not found + * | | + * "Journal Corruption" | + * _____________|_________ + * | | + * nth trans corrupt OR nth trans + * and (n+1)th interrupted interrupted + * before commit block + * could reach the disk. + * (Cannot find the difference in above + * mentioned conditions. Hence assume + * "Interrupted Commit".) + */ + + /* Found an expected commit block: if checksums + * are present verify them in PASS_SCAN; else not + * much to do other than move on to the next sequence * number. */ + if (pass == PASS_SCAN && + JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_COMPAT_CHECKSUM)) { + int chksum_err, chksum_seen; + struct commit_header *cbh = + (struct commit_header *)bh->b_data; + unsigned found_chksum = + be32_to_cpu(cbh->h_chksum[0]); + + chksum_err = chksum_seen = 0; + + if (info->end_transaction) { + printk(KERN_ERR "JBD: Transaction %u " + "found to be corrupt.\n", + next_commit_ID - 1); + brelse(bh); + break; + } + + if (crc32_sum == found_chksum && + cbh->h_chksum_type == JBD2_CRC32_CHKSUM && + cbh->h_chksum_size == + JBD2_CRC32_CHKSUM_SIZE) + chksum_seen = 1; + else if (!(cbh->h_chksum_type == 0 && + cbh->h_chksum_size == 0 && + found_chksum == 0 && + !chksum_seen)) + /* + * If fs is mounted using an old kernel and then + * kernel with journal_chksum is used then we + * get a situation where the journal flag has + * checksum flag set but checksums are not + * present i.e chksum = 0, in the individual + * commit blocks. + * Hence to avoid checksum failures, in this + * situation, this extra check is added. + */ + chksum_err = 1; + + if (chksum_err) { + info->end_transaction = next_commit_ID; + + if (!JBD2_HAS_COMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){ + printk(KERN_ERR + "JBD: Transaction %u " + "found to be corrupt.\n", + next_commit_ID); + brelse(bh); + break; + } + } + crc32_sum = ~0; + } brelse(bh); next_commit_ID++; continue; @@ -554,9 +688,10 @@ static int do_one_pass(journal_t *journal, * transaction marks the end of the valid log. */ - if (pass == PASS_SCAN) - info->end_transaction = next_commit_ID; - else { + if (pass == PASS_SCAN) { + if (!info->end_transaction) + info->end_transaction = next_commit_ID; + } else { /* It's really bad news if different passes end up at * different places (but possible due to IO errors). */ if (info->end_transaction != next_commit_ID) { |
