| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * linux/fs/jbd2/commit.c |
| * |
| * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 |
| * |
| * Copyright 1998 Red Hat corp --- All Rights Reserved |
| * |
| * Journal commit routines for the generic filesystem journaling code; |
| * part of the ext2fs journaling system. |
| */ |
| |
| #include <linux/time.h> |
| #include <linux/fs.h> |
| #include <linux/jbd2.h> |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/jiffies.h> |
| #include <linux/crc32.h> |
| #include <linux/writeback.h> |
| #include <linux/backing-dev.h> |
| #include <linux/bio.h> |
| #include <linux/blkdev.h> |
| #include <linux/bitops.h> |
| #include <trace/events/jbd2.h> |
| |
| /* |
| * IO end handler for temporary buffer_heads handling writes to the journal. |
| */ |
| static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate) |
| { |
| struct buffer_head *orig_bh = bh->b_private; |
| |
| BUFFER_TRACE(bh, ""); |
| if (uptodate) |
| set_buffer_uptodate(bh); |
| else |
| clear_buffer_uptodate(bh); |
| if (orig_bh) { |
| clear_bit_unlock(BH_Shadow, &orig_bh->b_state); |
| smp_mb__after_atomic(); |
| wake_up_bit(&orig_bh->b_state, BH_Shadow); |
| } |
| unlock_buffer(bh); |
| } |
| |
| /* |
| * When an ext4 file is truncated, it is possible that some pages are not |
| * successfully freed, because they are attached to a committing transaction. |
| * After the transaction commits, these pages are left on the LRU, with no |
| * ->mapping, and with attached buffers. These pages are trivially reclaimable |
| * by the VM, but their apparent absence upsets the VM accounting, and it makes |
| * the numbers in /proc/meminfo look odd. |
| * |
| * So here, we have a buffer which has just come off the forget list. Look to |
| * see if we can strip all buffers from the backing page. |
| * |
| * Called under lock_journal(), and possibly under journal_datalist_lock. The |
| * caller provided us with a ref against the buffer, and we drop that here. |
| */ |
| static void release_buffer_page(struct buffer_head *bh) |
| { |
| struct page *page; |
| |
| if (buffer_dirty(bh)) |
| goto nope; |
| if (atomic_read(&bh->b_count) != 1) |
| goto nope; |
| page = bh->b_page; |
| if (!page) |
| goto nope; |
| if (page->mapping) |
| goto nope; |
| |
| /* OK, it's a truncated page */ |
| if (!trylock_page(page)) |
| goto nope; |
| |
| get_page(page); |
| __brelse(bh); |
| try_to_free_buffers(page); |
| unlock_page(page); |
| put_page(page); |
| return; |
| |
| nope: |
| __brelse(bh); |
| } |
| |
| static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh) |
| { |
| struct commit_header *h; |
| __u32 csum; |
| |
| if (!jbd2_journal_has_csum_v2or3(j)) |
| return; |
| |
| h = (struct commit_header *)(bh->b_data); |
| h->h_chksum_type = 0; |
| h->h_chksum_size = 0; |
| h->h_chksum[0] = 0; |
| csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize); |
| h->h_chksum[0] = cpu_to_be32(csum); |
| } |
| |
| /* |
| * 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_submit_commit_record(journal_t *journal, |
| transaction_t *commit_transaction, |
| struct buffer_head **cbh, |
| __u32 crc32_sum) |
| { |
| struct commit_header *tmp; |
| struct buffer_head *bh; |
| int ret; |
| struct timespec64 now; |
| |
| *cbh = NULL; |
| |
| if (is_journal_aborted(journal)) |
| return 0; |
| |
| bh = jbd2_journal_get_descriptor_buffer(commit_transaction, |
| JBD2_COMMIT_BLOCK); |
| if (!bh) |
| return 1; |
| |
| tmp = (struct commit_header *)bh->b_data; |
| ktime_get_coarse_real_ts64(&now); |
| tmp->h_commit_sec = cpu_to_be64(now.tv_sec); |
| tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec); |
| |
| if (jbd2_has_feature_checksum(journal)) { |
| tmp->h_chksum_type = JBD2_CRC32_CHKSUM; |
| tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE; |
| tmp->h_chksum[0] = cpu_to_be32(crc32_sum); |
| } |
| jbd2_commit_block_csum_set(journal, bh); |
| |
| BUFFER_TRACE(bh, "submit commit block"); |
| lock_buffer(bh); |
| clear_buffer_dirty(bh); |
| set_buffer_uptodate(bh); |
| bh->b_end_io = journal_end_buffer_io_sync; |
| |
| if (journal->j_flags & JBD2_BARRIER && |
| !jbd2_has_feature_async_commit(journal)) |
| ret = submit_bh(REQ_OP_WRITE, |
| REQ_SYNC | REQ_PREFLUSH | REQ_FUA, bh); |
| else |
| ret = submit_bh(REQ_OP_WRITE, REQ_SYNC, bh); |
| |
| *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(journal_t *journal, |
| struct buffer_head *bh) |
| { |
| int ret = 0; |
| |
| clear_buffer_dirty(bh); |
| wait_on_buffer(bh); |
| |
| if (unlikely(!buffer_uptodate(bh))) |
| ret = -EIO; |
| put_bh(bh); /* One for getblk() */ |
| |
| return ret; |
| } |
| |
| /* |
| * write the filemap data using writepage() address_space_operations. |
| * We don't do block allocation here even for delalloc. We don't |
| * use writepages() because with delayed allocation we may be doing |
| * block allocation in writepages(). |
| */ |
| int jbd2_journal_submit_inode_data_buffers(struct jbd2_inode *jinode) |
| { |
| struct address_space *mapping = jinode->i_vfs_inode->i_mapping; |
| struct writeback_control wbc = { |
| .sync_mode = WB_SYNC_ALL, |
| .nr_to_write = mapping->nrpages * 2, |
| .range_start = jinode->i_dirty_start, |
| .range_end = jinode->i_dirty_end, |
| }; |
| |
| /* |
| * submit the inode data buffers. We use writepage |
| * instead of writepages. Because writepages can do |
| * block allocation with delalloc. We need to write |
| * only allocated blocks here. |
| */ |
| return generic_writepages(mapping, &wbc); |
| } |
| |
| /* Send all the data buffers related to an inode */ |
| int jbd2_submit_inode_data(struct jbd2_inode *jinode) |
| { |
| |
| if (!jinode || !(jinode->i_flags & JI_WRITE_DATA)) |
| return 0; |
| |
| trace_jbd2_submit_inode_data(jinode->i_vfs_inode); |
| return jbd2_journal_submit_inode_data_buffers(jinode); |
| |
| } |
| EXPORT_SYMBOL(jbd2_submit_inode_data); |
| |
| int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode) |
| { |
| if (!jinode || !(jinode->i_flags & JI_WAIT_DATA) || |
| !jinode->i_vfs_inode || !jinode->i_vfs_inode->i_mapping) |
| return 0; |
| return filemap_fdatawait_range_keep_errors( |
| jinode->i_vfs_inode->i_mapping, jinode->i_dirty_start, |
| jinode->i_dirty_end); |
| } |
| EXPORT_SYMBOL(jbd2_wait_inode_data); |
| |
| /* |
| * Submit all the data buffers of inode associated with the transaction to |
| * disk. |
| * |
| * We are in a committing transaction. Therefore no new inode can be added to |
| * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently |
| * operate on from being released while we write out pages. |
| */ |
| static int journal_submit_data_buffers(journal_t *journal, |
| transaction_t *commit_transaction) |
| { |
| struct jbd2_inode *jinode; |
| int err, ret = 0; |
| |
| spin_lock(&journal->j_list_lock); |
| list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) { |
| if (!(jinode->i_flags & JI_WRITE_DATA)) |
| continue; |
| jinode->i_flags |= JI_COMMIT_RUNNING; |
| spin_unlock(&journal->j_list_lock); |
| /* submit the inode data buffers. */ |
| trace_jbd2_submit_inode_data(jinode->i_vfs_inode); |
| if (journal->j_submit_inode_data_buffers) { |
| err = journal->j_submit_inode_data_buffers(jinode); |
| if (!ret) |
| ret = err; |
| } |
| spin_lock(&journal->j_list_lock); |
| J_ASSERT(jinode->i_transaction == commit_transaction); |
| jinode->i_flags &= ~JI_COMMIT_RUNNING; |
| smp_mb(); |
| wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING); |
| } |
| spin_unlock(&journal->j_list_lock); |
| return ret; |
| } |
| |
| int jbd2_journal_finish_inode_data_buffers(struct jbd2_inode *jinode) |
| { |
| struct address_space *mapping = jinode->i_vfs_inode->i_mapping; |
| |
| return filemap_fdatawait_range_keep_errors(mapping, |
| jinode->i_dirty_start, |
| jinode->i_dirty_end); |
| } |
| |
| /* |
| * Wait for data submitted for writeout, refile inodes to proper |
| * transaction if needed. |
| * |
| */ |
| static int journal_finish_inode_data_buffers(journal_t *journal, |
| transaction_t *commit_transaction) |
| { |
| struct jbd2_inode *jinode, *next_i; |
| int err, ret = 0; |
| |
| /* For locking, see the comment in journal_submit_data_buffers() */ |
| spin_lock(&journal->j_list_lock); |
| list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) { |
| if (!(jinode->i_flags & JI_WAIT_DATA)) |
| continue; |
| jinode->i_flags |= JI_COMMIT_RUNNING; |
| spin_unlock(&journal->j_list_lock); |
| /* wait for the inode data buffers writeout. */ |
| if (journal->j_finish_inode_data_buffers) { |
| err = journal->j_finish_inode_data_buffers(jinode); |
| if (!ret) |
| ret = err; |
| } |
| spin_lock(&journal->j_list_lock); |
| jinode->i_flags &= ~JI_COMMIT_RUNNING; |
| smp_mb(); |
| wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING); |
| } |
| |
| /* Now refile inode to proper lists */ |
| list_for_each_entry_safe(jinode, next_i, |
| &commit_transaction->t_inode_list, i_list) { |
| list_del(&jinode->i_list); |
| if (jinode->i_next_transaction) { |
| jinode->i_transaction = jinode->i_next_transaction; |
| jinode->i_next_transaction = NULL; |
| list_add(&jinode->i_list, |
| &jinode->i_transaction->t_inode_list); |
| } else { |
| jinode->i_transaction = NULL; |
| jinode->i_dirty_start = 0; |
| jinode->i_dirty_end = 0; |
| } |
| } |
| spin_unlock(&journal->j_list_lock); |
| |
| return ret; |
| } |
| |
| 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); |
| checksum = crc32_be(crc32_sum, |
| (void *)(addr + offset_in_page(bh->b_data)), bh->b_size); |
| kunmap_atomic(addr); |
| |
| return checksum; |
| } |
| |
| static void write_tag_block(journal_t *j, journal_block_tag_t *tag, |
| unsigned long long block) |
| { |
| tag->t_blocknr = cpu_to_be32(block & (u32)~0); |
| if (jbd2_has_feature_64bit(j)) |
| tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1); |
| } |
| |
| static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag, |
| struct buffer_head *bh, __u32 sequence) |
| { |
| journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag; |
| struct page *page = bh->b_page; |
| __u8 *addr; |
| __u32 csum32; |
| __be32 seq; |
| |
| if (!jbd2_journal_has_csum_v2or3(j)) |
| return; |
| |
| seq = cpu_to_be32(sequence); |
| addr = kmap_atomic(page); |
| csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq)); |
| csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data), |
| bh->b_size); |
| kunmap_atomic(addr); |
| |
| if (jbd2_has_feature_csum3(j)) |
| tag3->t_checksum = cpu_to_be32(csum32); |
| else |
| tag->t_checksum = cpu_to_be16(csum32); |
| } |
| /* |
| * jbd2_journal_commit_transaction |
| * |
| * The primary function for committing a transaction to the log. This |
| * function is called by the journal thread to begin a complete commit. |
| */ |
| void jbd2_journal_commit_transaction(journal_t *journal) |
| { |
| struct transaction_stats_s stats; |
| transaction_t *commit_transaction; |
| struct journal_head *jh; |
| struct buffer_head *descriptor; |
| struct buffer_head **wbuf = journal->j_wbuf; |
| int bufs; |
| int flags; |
| int err; |
| unsigned long long blocknr; |
| ktime_t start_time; |
| u64 commit_time; |
| char *tagp = NULL; |
| journal_block_tag_t *tag = NULL; |
| int space_left = 0; |
| int first_tag = 0; |
| int tag_flag; |
| int i; |
| int tag_bytes = journal_tag_bytes(journal); |
| struct buffer_head *cbh = NULL; /* For transactional checksums */ |
| __u32 crc32_sum = ~0; |
| struct blk_plug plug; |
| /* Tail of the journal */ |
| unsigned long first_block; |
| tid_t first_tid; |
| int update_tail; |
| int csum_size = 0; |
| LIST_HEAD(io_bufs); |
| LIST_HEAD(log_bufs); |
| |
| if (jbd2_journal_has_csum_v2or3(journal)) |
| csum_size = sizeof(struct jbd2_journal_block_tail); |
| |
| /* |
| * First job: lock down the current transaction and wait for |
| * all outstanding updates to complete. |
| */ |
| |
| /* Do we need to erase the effects of a prior jbd2_journal_flush? */ |
| if (journal->j_flags & JBD2_FLUSHED) { |
| jbd_debug(3, "super block updated\n"); |
| mutex_lock_io(&journal->j_checkpoint_mutex); |
| /* |
| * We hold j_checkpoint_mutex so tail cannot change under us. |
| * We don't need any special data guarantees for writing sb |
| * since journal is empty and it is ok for write to be |
| * flushed only with transaction commit. |
| */ |
| jbd2_journal_update_sb_log_tail(journal, |
| journal->j_tail_sequence, |
| journal->j_tail, |
| REQ_SYNC); |
| mutex_unlock(&journal->j_checkpoint_mutex); |
| } else { |
| jbd_debug(3, "superblock not updated\n"); |
| } |
| |
| J_ASSERT(journal->j_running_transaction != NULL); |
| J_ASSERT(journal->j_committing_transaction == NULL); |
| |
| write_lock(&journal->j_state_lock); |
| journal->j_flags |= JBD2_FULL_COMMIT_ONGOING; |
| while (journal->j_flags & JBD2_FAST_COMMIT_ONGOING) { |
| DEFINE_WAIT(wait); |
| |
| prepare_to_wait(&journal->j_fc_wait, &wait, |
| TASK_UNINTERRUPTIBLE); |
| write_unlock(&journal->j_state_lock); |
| schedule(); |
| write_lock(&journal->j_state_lock); |
| finish_wait(&journal->j_fc_wait, &wait); |
| /* |
| * TODO: by blocking fast commits here, we are increasing |
| * fsync() latency slightly. Strictly speaking, we don't need |
| * to block fast commits until the transaction enters T_FLUSH |
| * state. So an optimization is possible where we block new fast |
| * commits here and wait for existing ones to complete |
| * just before we enter T_FLUSH. That way, the existing fast |
| * commits and this full commit can proceed parallely. |
| */ |
| } |
| write_unlock(&journal->j_state_lock); |
| |
| commit_transaction = journal->j_running_transaction; |
| |
| trace_jbd2_start_commit(journal, commit_transaction); |
| jbd_debug(1, "JBD2: starting commit of transaction %d\n", |
| commit_transaction->t_tid); |
| |
| write_lock(&journal->j_state_lock); |
| journal->j_fc_off = 0; |
| J_ASSERT(commit_transaction->t_state == T_RUNNING); |
| commit_transaction->t_state = T_LOCKED; |
| |
| trace_jbd2_commit_locking(journal, commit_transaction); |
| stats.run.rs_wait = commit_transaction->t_max_wait; |
| stats.run.rs_request_delay = 0; |
| stats.run.rs_locked = jiffies; |
| if (commit_transaction->t_requested) |
| stats.run.rs_request_delay = |
| jbd2_time_diff(commit_transaction->t_requested, |
| stats.run.rs_locked); |
| stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start, |
| stats.run.rs_locked); |
| |
| spin_lock(&commit_transaction->t_handle_lock); |
| while (atomic_read(&commit_transaction->t_updates)) { |
| DEFINE_WAIT(wait); |
| |
| prepare_to_wait(&journal->j_wait_updates, &wait, |
| TASK_UNINTERRUPTIBLE); |
| if (atomic_read(&commit_transaction->t_updates)) { |
| spin_unlock(&commit_transaction->t_handle_lock); |
| write_unlock(&journal->j_state_lock); |
| schedule(); |
| write_lock(&journal->j_state_lock); |
| spin_lock(&commit_transaction->t_handle_lock); |
| } |
| finish_wait(&journal->j_wait_updates, &wait); |
| } |
| spin_unlock(&commit_transaction->t_handle_lock); |
| commit_transaction->t_state = T_SWITCH; |
| write_unlock(&journal->j_state_lock); |
| |
| J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <= |
| journal->j_max_transaction_buffers); |
| |
| /* |
| * First thing we are allowed to do is to discard any remaining |
| * BJ_Reserved buffers. Note, it is _not_ permissible to assume |
| * that there are no such buffers: if a large filesystem |
| * operation like a truncate needs to split itself over multiple |
| * transactions, then it may try to do a jbd2_journal_restart() while |
| * there are still BJ_Reserved buffers outstanding. These must |
| * be released cleanly from the current transaction. |
| * |
| * In this case, the filesystem must still reserve write access |
| * again before modifying the buffer in the new transaction, but |
| * we do not require it to remember exactly which old buffers it |
| * has reserved. This is consistent with the existing behaviour |
| * that multiple jbd2_journal_get_write_access() calls to the same |
| * buffer are perfectly permissible. |
| */ |
| while (commit_transaction->t_reserved_list) { |
| jh = commit_transaction->t_reserved_list; |
| JBUFFER_TRACE(jh, "reserved, unused: refile"); |
| /* |
| * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may |
| * leave undo-committed data. |
| */ |
| if (jh->b_committed_data) { |
| struct buffer_head *bh = jh2bh(jh); |
| |
| spin_lock(&jh->b_state_lock); |
| jbd2_free(jh->b_committed_data, bh->b_size); |
| jh->b_committed_data = NULL; |
| spin_unlock(&jh->b_state_lock); |
| } |
| jbd2_journal_refile_buffer(journal, jh); |
| } |
| |
| /* |
| * Now try to drop any written-back buffers from the journal's |
| * checkpoint lists. We do this *before* commit because it potentially |
| * frees some memory |
| */ |
| spin_lock(&journal->j_list_lock); |
| __jbd2_journal_clean_checkpoint_list(journal, false); |
| spin_unlock(&journal->j_list_lock); |
| |
| jbd_debug(3, "JBD2: commit phase 1\n"); |
| |
| /* |
| * Clear revoked flag to reflect there is no revoked buffers |
| * in the next transaction which is going to be started. |
| */ |
| jbd2_clear_buffer_revoked_flags(journal); |
| |
| /* |
| * Switch to a new revoke table. |
| */ |
| jbd2_journal_switch_revoke_table(journal); |
| |
| /* |
| * Reserved credits cannot be claimed anymore, free them |
| */ |
| atomic_sub(atomic_read(&journal->j_reserved_credits), |
| &commit_transaction->t_outstanding_credits); |
| |
| write_lock(&journal->j_state_lock); |
| trace_jbd2_commit_flushing(journal, commit_transaction); |
| stats.run.rs_flushing = jiffies; |
| stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked, |
| stats.run.rs_flushing); |
| |
| commit_transaction->t_state = T_FLUSH; |
| journal->j_committing_transaction = commit_transaction; |
| journal->j_running_transaction = NULL; |
| start_time = ktime_get(); |
| commit_transaction->t_log_start = journal->j_head; |
| wake_up(&journal->j_wait_transaction_locked); |
| write_unlock(&journal->j_state_lock); |
| |
| jbd_debug(3, "JBD2: commit phase 2a\n"); |
| |
| /* |
| * Now start flushing things to disk, in the order they appear |
| * on the transaction lists. Data blocks go first. |
| */ |
| err = journal_submit_data_buffers(journal, commit_transaction); |
| if (err) |
| jbd2_journal_abort(journal, err); |
| |
| blk_start_plug(&plug); |
| jbd2_journal_write_revoke_records(commit_transaction, &log_bufs); |
| |
| jbd_debug(3, "JBD2: commit phase 2b\n"); |
| |
| /* |
| * Way to go: we have now written out all of the data for a |
| * transaction! Now comes the tricky part: we need to write out |
| * metadata. Loop over the transaction's entire buffer list: |
| */ |
| write_lock(&journal->j_state_lock); |
| commit_transaction->t_state = T_COMMIT; |
| write_unlock(&journal->j_state_lock); |
| |
| trace_jbd2_commit_logging(journal, commit_transaction); |
| stats.run.rs_logging = jiffies; |
| stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing, |
| stats.run.rs_logging); |
| stats.run.rs_blocks = commit_transaction->t_nr_buffers; |
| stats.run.rs_blocks_logged = 0; |
| |
| J_ASSERT(commit_transaction->t_nr_buffers <= |
| atomic_read(&commit_transaction->t_outstanding_credits)); |
| |
| err = 0; |
| bufs = 0; |
| descriptor = NULL; |
| while (commit_transaction->t_buffers) { |
| |
| /* Find the next buffer to be journaled... */ |
| |
| jh = commit_transaction->t_buffers; |
| |
| /* If we're in abort mode, we just un-journal the buffer and |
| release it. */ |
| |
| if (is_journal_aborted(journal)) { |
| clear_buffer_jbddirty(jh2bh(jh)); |
| JBUFFER_TRACE(jh, "journal is aborting: refile"); |
| jbd2_buffer_abort_trigger(jh, |
| jh->b_frozen_data ? |
| jh->b_frozen_triggers : |
| jh->b_triggers); |
| jbd2_journal_refile_buffer(journal, jh); |
| /* If that was the last one, we need to clean up |
| * any descriptor buffers which may have been |
| * already allocated, even if we are now |
| * aborting. */ |
| if (!commit_transaction->t_buffers) |
| goto start_journal_io; |
| continue; |
| } |
| |
| /* Make sure we have a descriptor block in which to |
| record the metadata buffer. */ |
| |
| if (!descriptor) { |
| J_ASSERT (bufs == 0); |
| |
| jbd_debug(4, "JBD2: get descriptor\n"); |
| |
| descriptor = jbd2_journal_get_descriptor_buffer( |
| commit_transaction, |
| JBD2_DESCRIPTOR_BLOCK); |
| if (!descriptor) { |
| jbd2_journal_abort(journal, -EIO); |
| continue; |
| } |
| |
| jbd_debug(4, "JBD2: got buffer %llu (%p)\n", |
| (unsigned long long)descriptor->b_blocknr, |
| descriptor->b_data); |
| tagp = &descriptor->b_data[sizeof(journal_header_t)]; |
| space_left = descriptor->b_size - |
| sizeof(journal_header_t); |
| first_tag = 1; |
| set_buffer_jwrite(descriptor); |
| set_buffer_dirty(descriptor); |
| wbuf[bufs++] = descriptor; |
| |
| /* Record it so that we can wait for IO |
| completion later */ |
| BUFFER_TRACE(descriptor, "ph3: file as descriptor"); |
| jbd2_file_log_bh(&log_bufs, descriptor); |
| } |
| |
| /* Where is the buffer to be written? */ |
| |
| err = jbd2_journal_next_log_block(journal, &blocknr); |
| /* If the block mapping failed, just abandon the buffer |
| and repeat this loop: we'll fall into the |
| refile-on-abort condition above. */ |
| if (err) { |
| jbd2_journal_abort(journal, err); |
| continue; |
| } |
| |
| /* |
| * start_this_handle() uses t_outstanding_credits to determine |
| * the free space in the log. |
| */ |
| atomic_dec(&commit_transaction->t_outstanding_credits); |
| |
| /* Bump b_count to prevent truncate from stumbling over |
| the shadowed buffer! @@@ This can go if we ever get |
| rid of the shadow pairing of buffers. */ |
| atomic_inc(&jh2bh(jh)->b_count); |
| |
| /* |
| * Make a temporary IO buffer with which to write it out |
| * (this will requeue the metadata buffer to BJ_Shadow). |
| */ |
| set_bit(BH_JWrite, &jh2bh(jh)->b_state); |
| JBUFFER_TRACE(jh, "ph3: write metadata"); |
| flags = jbd2_journal_write_metadata_buffer(commit_transaction, |
| jh, &wbuf[bufs], blocknr); |
| if (flags < 0) { |
| jbd2_journal_abort(journal, flags); |
| continue; |
| } |
| jbd2_file_log_bh(&io_bufs, wbuf[bufs]); |
| |
| /* Record the new block's tag in the current descriptor |
| buffer */ |
| |
| tag_flag = 0; |
| if (flags & 1) |
| tag_flag |= JBD2_FLAG_ESCAPE; |
| if (!first_tag) |
| tag_flag |= JBD2_FLAG_SAME_UUID; |
| |
| tag = (journal_block_tag_t *) tagp; |
| write_tag_block(journal, tag, jh2bh(jh)->b_blocknr); |
| tag->t_flags = cpu_to_be16(tag_flag); |
| jbd2_block_tag_csum_set(journal, tag, wbuf[bufs], |
| commit_transaction->t_tid); |
| tagp += tag_bytes; |
| space_left -= tag_bytes; |
| bufs++; |
| |
| if (first_tag) { |
| memcpy (tagp, journal->j_uuid, 16); |
| tagp += 16; |
| space_left -= 16; |
| first_tag = 0; |
| } |
| |
| /* If there's no more to do, or if the descriptor is full, |
| let the IO rip! */ |
| |
| if (bufs == journal->j_wbufsize || |
| commit_transaction->t_buffers == NULL || |
| space_left < tag_bytes + 16 + csum_size) { |
| |
| jbd_debug(4, "JBD2: Submit %d IOs\n", bufs); |
| |
| /* Write an end-of-descriptor marker before |
| submitting the IOs. "tag" still points to |
| the last tag we set up. */ |
| |
| tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG); |
| start_journal_io: |
| if (descriptor) |
| jbd2_descriptor_block_csum_set(journal, |
| descriptor); |
| |
| for (i = 0; i < bufs; i++) { |
| struct buffer_head *bh = wbuf[i]; |
| /* |
| * Compute checksum. |
| */ |
| if (jbd2_has_feature_checksum(journal)) { |
| crc32_sum = |
| jbd2_checksum_data(crc32_sum, bh); |
| } |
| |
| lock_buffer(bh); |
| clear_buffer_dirty(bh); |
| set_buffer_uptodate(bh); |
| bh->b_end_io = journal_end_buffer_io_sync; |
| submit_bh(REQ_OP_WRITE, REQ_SYNC, bh); |
| } |
| cond_resched(); |
| |
| /* Force a new descriptor to be generated next |
| time round the loop. */ |
| descriptor = NULL; |
| bufs = 0; |
| } |
| } |
| |
| err = journal_finish_inode_data_buffers(journal, commit_transaction); |
| if (err) { |
| printk(KERN_WARNING |
| "JBD2: Detected IO errors while flushing file data " |
| "on %s\n", journal->j_devname); |
| if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR) |
| jbd2_journal_abort(journal, err); |
| err = 0; |
| } |
| |
| /* |
| * Get current oldest transaction in the log before we issue flush |
| * to the filesystem device. After the flush we can be sure that |
| * blocks of all older transactions are checkpointed to persistent |
| * storage and we will be safe to update journal start in the |
| * superblock with the numbers we get here. |
| */ |
| update_tail = |
| jbd2_journal_get_log_tail(journal, &first_tid, &first_block); |
| |
| write_lock(&journal->j_state_lock); |
| if (update_tail) { |
| long freed = first_block - journal->j_tail; |
| |
| 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 < jbd2_journal_get_max_txn_bufs(journal)) |
| update_tail = 0; |
| } |
| J_ASSERT(commit_transaction->t_state == T_COMMIT); |
| commit_transaction->t_state = T_COMMIT_DFLUSH; |
| write_unlock(&journal->j_state_lock); |
| |
| /* |
| * If the journal is not located on the file system device, |
| * then we must flush the file system device before we issue |
| * the commit record |
| */ |
| if (commit_transaction->t_need_data_flush && |
| (journal->j_fs_dev != journal->j_dev) && |
| (journal->j_flags & JBD2_BARRIER)) |
| blkdev_issue_flush(journal->j_fs_dev); |
| |
| /* Done it all: now write the commit record asynchronously. */ |
| if (jbd2_has_feature_async_commit(journal)) { |
| err = journal_submit_commit_record(journal, commit_transaction, |
| &cbh, crc32_sum); |
| if (err) |
| jbd2_journal_abort(journal, err); |
| } |
| |
| blk_finish_plug(&plug); |
| |
| /* 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 |
| transaction's t_log_list queue, and metadata buffers are on |
| the io_bufs list. |
| |
| Wait for the buffers in reverse order. That way we are |
| less likely to be woken up until all IOs have completed, and |
| so we incur less scheduling load. |
| */ |
| |
| jbd_debug(3, "JBD2: commit phase 3\n"); |
| |
| while (!list_empty(&io_bufs)) { |
| struct buffer_head *bh = list_entry(io_bufs.prev, |
| struct buffer_head, |
| b_assoc_buffers); |
| |
| wait_on_buffer(bh); |
| cond_resched(); |
| |
| if (unlikely(!buffer_uptodate(bh))) |
| err = -EIO; |
| jbd2_unfile_log_bh(bh); |
| stats.run.rs_blocks_logged++; |
| |
| /* |
| * The list contains temporary buffer heads created by |
| * jbd2_journal_write_metadata_buffer(). |
| */ |
| BUFFER_TRACE(bh, "dumping temporary bh"); |
| __brelse(bh); |
| J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); |
| free_buffer_head(bh); |
| |
| /* We also have to refile the corresponding shadowed buffer */ |
| jh = commit_transaction->t_shadow_list->b_tprev; |
| bh = jh2bh(jh); |
| clear_buffer_jwrite(bh); |
| J_ASSERT_BH(bh, buffer_jbddirty(bh)); |
| J_ASSERT_BH(bh, !buffer_shadow(bh)); |
| |
| /* The metadata is now released for reuse, but we need |
| to remember it against this transaction so that when |
| we finally commit, we can do any checkpointing |
| required. */ |
| JBUFFER_TRACE(jh, "file as BJ_Forget"); |
| jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget); |
| JBUFFER_TRACE(jh, "brelse shadowed buffer"); |
| __brelse(bh); |
| } |
| |
| J_ASSERT (commit_transaction->t_shadow_list == NULL); |
| |
| jbd_debug(3, "JBD2: commit phase 4\n"); |
| |
| /* Here we wait for the revoke record and descriptor record buffers */ |
| while (!list_empty(&log_bufs)) { |
| struct buffer_head *bh; |
| |
| bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers); |
| wait_on_buffer(bh); |
| cond_resched(); |
| |
| if (unlikely(!buffer_uptodate(bh))) |
| err = -EIO; |
| |
| BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); |
| clear_buffer_jwrite(bh); |
| jbd2_unfile_log_bh(bh); |
| stats.run.rs_blocks_logged++; |
| __brelse(bh); /* One for getblk */ |
| /* AKPM: bforget here */ |
| } |
| |
| if (err) |
| jbd2_journal_abort(journal, err); |
| |
| jbd_debug(3, "JBD2: commit phase 5\n"); |
| write_lock(&journal->j_state_lock); |
| J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH); |
| commit_transaction->t_state = T_COMMIT_JFLUSH; |
| write_unlock(&journal->j_state_lock); |
| |
| if (!jbd2_has_feature_async_commit(journal)) { |
| err = journal_submit_commit_record(journal, commit_transaction, |
| &cbh, crc32_sum); |
| if (err) |
| jbd2_journal_abort(journal, err); |
| } |
| if (cbh) |
| err = journal_wait_on_commit_record(journal, cbh); |
| stats.run.rs_blocks_logged++; |
| if (jbd2_has_feature_async_commit(journal) && |
| journal->j_flags & JBD2_BARRIER) { |
| blkdev_issue_flush(journal->j_dev); |
| } |
| |
| if (err) |
| jbd2_journal_abort(journal, err); |
| |
| WARN_ON_ONCE( |
| atomic_read(&commit_transaction->t_outstanding_credits) < 0); |
| |
| /* |
| * Now disk caches for filesystem device are flushed so we are safe to |
| * erase checkpointed transactions from the log by updating journal |
| * superblock. |
| */ |
| if (update_tail) |
| jbd2_update_log_tail(journal, first_tid, first_block); |
| |
| /* End of a transaction! Finally, we can do checkpoint |
| processing: any buffers committed as a result of this |
| transaction can be removed from any checkpoint list it was on |
| before. */ |
| |
| jbd_debug(3, "JBD2: commit phase 6\n"); |
| |
| J_ASSERT(list_empty(&commit_transaction->t_inode_list)); |
| J_ASSERT(commit_transaction->t_buffers == NULL); |
| J_ASSERT(commit_transaction->t_checkpoint_list == NULL); |
| J_ASSERT(commit_transaction->t_shadow_list == NULL); |
| |
| restart_loop: |
| /* |
| * As there are other places (journal_unmap_buffer()) adding buffers |
| * to this list we have to be careful and hold the j_list_lock. |
| */ |
| spin_lock(&journal->j_list_lock); |
| while (commit_transaction->t_forget) { |
| transaction_t *cp_transaction; |
| struct buffer_head *bh; |
| int try_to_free = 0; |
| bool drop_ref; |
| |
| jh = commit_transaction->t_forget; |
| spin_unlock(&journal->j_list_lock); |
| bh = jh2bh(jh); |
| /* |
| * Get a reference so that bh cannot be freed before we are |
| * done with it. |
| */ |
| get_bh(bh); |
| spin_lock(&jh->b_state_lock); |
| J_ASSERT_JH(jh, jh->b_transaction == commit_transaction); |
| |
| /* |
| * If there is undo-protected committed data against |
| * this buffer, then we can remove it now. If it is a |
| * buffer needing such protection, the old frozen_data |
| * field now points to a committed version of the |
| * buffer, so rotate that field to the new committed |
| * data. |
| * |
| * Otherwise, we can just throw away the frozen data now. |
| * |
| * We also know that the frozen data has already fired |
| * its triggers if they exist, so we can clear that too. |
| */ |
| if (jh->b_committed_data) { |
| jbd2_free(jh->b_committed_data, bh->b_size); |
| jh->b_committed_data = NULL; |
| if (jh->b_frozen_data) { |
| jh->b_committed_data = jh->b_frozen_data; |
| jh->b_frozen_data = NULL; |
| jh->b_frozen_triggers = NULL; |
| } |
| } else if (jh->b_frozen_data) { |
| jbd2_free(jh->b_frozen_data, bh->b_size); |
| jh->b_frozen_data = NULL; |
| jh->b_frozen_triggers = NULL; |
| } |
| |
| spin_lock(&journal->j_list_lock); |
| cp_transaction = jh->b_cp_transaction; |
| if (cp_transaction) { |
| JBUFFER_TRACE(jh, "remove from old cp transaction"); |
| cp_transaction->t_chp_stats.cs_dropped++; |
| __jbd2_journal_remove_checkpoint(jh); |
| } |
| |
| /* Only re-checkpoint the buffer_head if it is marked |
| * dirty. If the buffer was added to the BJ_Forget list |
| * by jbd2_journal_forget, it may no longer be dirty and |
| * there's no point in keeping a checkpoint record for |
| * it. */ |
| |
| /* |
| * A buffer which has been freed while still being journaled |
| * by a previous transaction, refile the buffer to BJ_Forget of |
| * the running transaction. If the just committed transaction |
| * contains "add to orphan" operation, we can completely |
| * invalidate the buffer now. We are rather through in that |
| * since the buffer may be still accessible when blocksize < |
| * pagesize and it is attached to the last partial page. |
| */ |
| if (buffer_freed(bh) && !jh->b_next_transaction) { |
| struct address_space *mapping; |
| |
| clear_buffer_freed(bh); |
| clear_buffer_jbddirty(bh); |
| |
| /* |
| * Block device buffers need to stay mapped all the |
| * time, so it is enough to clear buffer_jbddirty and |
| * buffer_freed bits. For the file mapping buffers (i.e. |
| * journalled data) we need to unmap buffer and clear |
| * more bits. We also need to be careful about the check |
| * because the data page mapping can get cleared under |
| * our hands. Note that if mapping == NULL, we don't |
| * need to make buffer unmapped because the page is |
| * already detached from the mapping and buffers cannot |
| * get reused. |
| */ |
| mapping = READ_ONCE(bh->b_page->mapping); |
| if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) { |
| clear_buffer_mapped(bh); |
| clear_buffer_new(bh); |
| clear_buffer_req(bh); |
| bh->b_bdev = NULL; |
| } |
| } |
| |
| if (buffer_jbddirty(bh)) { |
| JBUFFER_TRACE(jh, "add to new checkpointing trans"); |
| __jbd2_journal_insert_checkpoint(jh, commit_transaction); |
| if (is_journal_aborted(journal)) |
| clear_buffer_jbddirty(bh); |
| } else { |
| J_ASSERT_BH(bh, !buffer_dirty(bh)); |
| /* |
| * The buffer on BJ_Forget list and not jbddirty means |
| * it has been freed by this transaction and hence it |
| * could not have been reallocated until this |
| * transaction has committed. *BUT* it could be |
| * reallocated once we have written all the data to |
| * disk and before we process the buffer on BJ_Forget |
| * list. |
| */ |
| if (!jh->b_next_transaction) |
| try_to_free = 1; |
| } |
| JBUFFER_TRACE(jh, "refile or unfile buffer"); |
| drop_ref = __jbd2_journal_refile_buffer(jh); |
| spin_unlock(&jh->b_state_lock); |
| if (drop_ref) |
| jbd2_journal_put_journal_head(jh); |
| if (try_to_free) |
| release_buffer_page(bh); /* Drops bh reference */ |
| else |
| __brelse(bh); |
| cond_resched_lock(&journal->j_list_lock); |
| } |
| spin_unlock(&journal->j_list_lock); |
| /* |
| * This is a bit sleazy. We use j_list_lock to protect transition |
| * of a transaction into T_FINISHED state and calling |
| * __jbd2_journal_drop_transaction(). Otherwise we could race with |
| * other checkpointing code processing the transaction... |
| */ |
| write_lock(&journal->j_state_lock); |
| spin_lock(&journal->j_list_lock); |
| /* |
| * Now recheck if some buffers did not get attached to the transaction |
| * while the lock was dropped... |
| */ |
| if (commit_transaction->t_forget) { |
| spin_unlock(&journal->j_list_lock); |
| write_unlock(&journal->j_state_lock); |
| goto restart_loop; |
| } |
| |
| /* Add the transaction to the checkpoint list |
| * __journal_remove_checkpoint() can not destroy transaction |
| * under us because it is not marked as T_FINISHED yet */ |
| if (journal->j_checkpoint_transactions == NULL) { |
| journal->j_checkpoint_transactions = commit_transaction; |
| commit_transaction->t_cpnext = commit_transaction; |
| commit_transaction->t_cpprev = commit_transaction; |
| } else { |
| commit_transaction->t_cpnext = |
| journal->j_checkpoint_transactions; |
| commit_transaction->t_cpprev = |
| commit_transaction->t_cpnext->t_cpprev; |
| commit_transaction->t_cpnext->t_cpprev = |
| commit_transaction; |
| commit_transaction->t_cpprev->t_cpnext = |
| commit_transaction; |
| } |
| spin_unlock(&journal->j_list_lock); |
| |
| /* Done with this transaction! */ |
| |
| jbd_debug(3, "JBD2: commit phase 7\n"); |
| |
| J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH); |
| |
| commit_transaction->t_start = jiffies; |
| stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging, |
| commit_transaction->t_start); |
| |
| /* |
| * File the transaction statistics |
| */ |
| stats.ts_tid = commit_transaction->t_tid; |
| stats.run.rs_handle_count = |
| atomic_read(&commit_transaction->t_handle_count); |
| trace_jbd2_run_stats(journal->j_fs_dev->bd_dev, |
| commit_transaction->t_tid, &stats.run); |
| stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0; |
| |
| commit_transaction->t_state = T_COMMIT_CALLBACK; |
| J_ASSERT(commit_transaction == journal->j_committing_transaction); |
| journal->j_commit_sequence = commit_transaction->t_tid; |
| journal->j_committing_transaction = NULL; |
| commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); |
| |
| /* |
| * weight the commit time higher than the average time so we don't |
| * react too strongly to vast changes in the commit time |
| */ |
| if (likely(journal->j_average_commit_time)) |
| journal->j_average_commit_time = (commit_time + |
| journal->j_average_commit_time*3) / 4; |
| else |
| journal->j_average_commit_time = commit_time; |
| |
| write_unlock(&journal->j_state_lock); |
| |
| if (journal->j_commit_callback) |
| journal->j_commit_callback(journal, commit_transaction); |
| if (journal->j_fc_cleanup_callback) |
| journal->j_fc_cleanup_callback(journal, 1, commit_transaction->t_tid); |
| |
| trace_jbd2_end_commit(journal, commit_transaction); |
| jbd_debug(1, "JBD2: commit %d complete, head %d\n", |
| journal->j_commit_sequence, journal->j_tail_sequence); |
| |
| write_lock(&journal->j_state_lock); |
| journal->j_flags &= ~JBD2_FULL_COMMIT_ONGOING; |
| journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING; |
| spin_lock(&journal->j_list_lock); |
| commit_transaction->t_state = T_FINISHED; |
| /* Check if the transaction can be dropped now that we are finished */ |
| if (commit_transaction->t_checkpoint_list == NULL && |
| commit_transaction->t_checkpoint_io_list == NULL) { |
| __jbd2_journal_drop_transaction(journal, commit_transaction); |
| jbd2_journal_free_transaction(commit_transaction); |
| } |
| spin_unlock(&journal->j_list_lock); |
| write_unlock(&journal->j_state_lock); |
| wake_up(&journal->j_wait_done_commit); |
| wake_up(&journal->j_fc_wait); |
| |
| /* |
| * Calculate overall stats |
| */ |
| spin_lock(&journal->j_history_lock); |
| journal->j_stats.ts_tid++; |
| journal->j_stats.ts_requested += stats.ts_requested; |
| journal->j_stats.run.rs_wait += stats.run.rs_wait; |
| journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay; |
| journal->j_stats.run.rs_running += stats.run.rs_running; |
| journal->j_stats.run.rs_locked += stats.run.rs_locked; |
| journal->j_stats.run.rs_flushing += stats.run.rs_flushing; |
| journal->j_stats.run.rs_logging += stats.run.rs_logging; |
| journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count; |
| journal->j_stats.run.rs_blocks += stats.run.rs_blocks; |
| journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged; |
| spin_unlock(&journal->j_history_lock); |
| } |