new file mode 100644
@@ -0,0 +1,1160 @@
+// 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 j_list_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 folio *folio;
+
+ if (buffer_dirty(bh))
+ goto nope;
+ if (atomic_read(&bh->b_count) != 1)
+ goto nope;
+ folio = bh->b_folio;
+ if (folio->mapping)
+ goto nope;
+
+ /* OK, it's a truncated page */
+ if (!folio_trylock(folio))
+ goto nope;
+
+ folio_get(folio);
+ __brelse(bh);
+ try_to_free_buffers(folio);
+ folio_unlock(folio);
+ folio_put(folio);
+ 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_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;
+ struct timespec64 now;
+ blk_opf_t write_flags = REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS;
+
+ *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))
+ write_flags |= REQ_PREFLUSH | REQ_FUA;
+
+ submit_bh(write_flags, bh);
+ *cbh = bh;
+ return 0;
+}
+
+/*
+ * 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;
+}
+
+/* Send all the data buffers related to an inode */
+int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode)
+{
+ if (!jinode || !(jinode->i_flags & JI_WRITE_DATA))
+ return 0;
+
+ trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
+ return journal->j_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;
+ }
+ cond_resched();
+ 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)
+{
+ char *addr;
+ __u32 checksum;
+
+ addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
+ checksum = crc32_be(crc32_sum, addr, bh->b_size);
+ kunmap_local(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;
+ __u8 *addr;
+ __u32 csum32;
+ __be32 seq;
+
+ if (!jbd2_journal_has_csum_v2or3(j))
+ return;
+
+ seq = cpu_to_be32(sequence);
+ addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
+ csum32 = jbd2_chksum(j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
+ csum32 = jbd2_chksum(csum32, addr, bh->b_size);
+ kunmap_local(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 escape;
+ 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) {
+ jbd2_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, 0);
+ mutex_unlock(&journal->j_checkpoint_mutex);
+ } else {
+ jbd2_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);
+ jbd2_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);
+
+ // waits for any t_updates to finish
+ jbd2_journal_wait_updates(journal);
+
+ commit_transaction->t_state = T_SWITCH;
+
+ 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.
+ * We use journal->j_state_lock here to serialize processing of
+ * t_reserved_list with eviction of buffers from journal_unmap_buffer().
+ */
+ 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);
+ }
+
+ write_unlock(&journal->j_state_lock);
+ /*
+ * 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, JBD2_SHRINK_BUSY_STOP);
+ spin_unlock(&journal->j_list_lock);
+
+ jbd2_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);
+
+ write_lock(&journal->j_state_lock);
+ /*
+ * Reserved credits cannot be claimed anymore, free them
+ */
+ atomic_sub(atomic_read(&journal->j_reserved_credits),
+ &commit_transaction->t_outstanding_credits);
+
+ 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_all(&journal->j_wait_transaction_locked);
+ write_unlock(&journal->j_state_lock);
+
+ jbd2_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);
+
+ jbd2_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));
+
+ 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);
+
+ jbd2_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;
+ }
+
+ jbd2_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");
+ escape = jbd2_journal_write_metadata_buffer(commit_transaction,
+ jh, &wbuf[bufs], blocknr);
+ jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
+
+ /* Record the new block's tag in the current descriptor
+ buffer */
+
+ tag_flag = 0;
+ if (escape)
+ 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) {
+
+ jbd2_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 | JBD2_JOURNAL_REQ_FLAGS,
+ 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 %d while flushing file data on %s\n",
+ err, journal->j_devname);
+ 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 < journal->j_max_transaction_buffers)
+ 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 and update the journal tail sequence.
+ */
+ if ((commit_transaction->t_need_data_flush || update_tail) &&
+ (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.
+ */
+
+ jbd2_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);
+
+ jbd2_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);
+
+ jbd2_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. */
+
+ jbd2_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_folio->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! */
+
+ jbd2_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);
+ WRITE_ONCE(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);
+ jbd2_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) {
+ __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);
+}
new file mode 100644
@@ -0,0 +1,996 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * linux/fs/jbd2/recovery.c
+ *
+ * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
+ *
+ * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
+ *
+ * Journal recovery routines for the generic filesystem journaling code;
+ * part of the ext2fs journaling system.
+ */
+
+#ifndef __KERNEL__
+#include "jfs_user.h"
+#else
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd2.h>
+#include <linux/errno.h>
+#include <linux/crc32.h>
+#include <linux/blkdev.h>
+#include <linux/string_choices.h>
+#endif
+
+/*
+ * Maintain information about the progress of the recovery job, so that
+ * the different passes can carry information between them.
+ */
+struct recovery_info
+{
+ tid_t start_transaction;
+ tid_t end_transaction;
+ unsigned long head_block;
+
+ int nr_replays;
+ int nr_revokes;
+ int nr_revoke_hits;
+};
+
+static int do_one_pass(journal_t *journal,
+ struct recovery_info *info, enum passtype pass);
+static int scan_revoke_records(journal_t *, enum passtype, struct buffer_head *,
+ tid_t, struct recovery_info *);
+
+#ifdef __KERNEL__
+
+/* Release readahead buffers after use */
+static void journal_brelse_array(struct buffer_head *b[], int n)
+{
+ while (--n >= 0)
+ brelse (b[n]);
+}
+
+
+/*
+ * When reading from the journal, we are going through the block device
+ * layer directly and so there is no readahead being done for us. We
+ * need to implement any readahead ourselves if we want it to happen at
+ * all. Recovery is basically one long sequential read, so make sure we
+ * do the IO in reasonably large chunks.
+ *
+ * This is not so critical that we need to be enormously clever about
+ * the readahead size, though. 128K is a purely arbitrary, good-enough
+ * fixed value.
+ */
+
+#define MAXBUF 8
+static void do_readahead(journal_t *journal, unsigned int start)
+{
+ unsigned int max, nbufs, next;
+ unsigned long long blocknr;
+ struct buffer_head *bh;
+
+ struct buffer_head * bufs[MAXBUF];
+
+ /* Do up to 128K of readahead */
+ max = start + (128 * 1024 / journal->j_blocksize);
+ 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. */
+
+ nbufs = 0;
+
+ for (next = start; next < max; next++) {
+ int err = jbd2_journal_bmap(journal, next, &blocknr);
+
+ if (err) {
+ printk(KERN_ERR "JBD2: bad block at offset %u\n",
+ next);
+ goto failed;
+ }
+
+ bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
+ if (!bh)
+ goto failed;
+
+ if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
+ bufs[nbufs++] = bh;
+ if (nbufs == MAXBUF) {
+ bh_readahead_batch(nbufs, bufs, 0);
+ journal_brelse_array(bufs, nbufs);
+ nbufs = 0;
+ }
+ } else
+ brelse(bh);
+ }
+
+ if (nbufs)
+ bh_readahead_batch(nbufs, bufs, 0);
+
+failed:
+ if (nbufs)
+ journal_brelse_array(bufs, nbufs);
+}
+
+#endif /* __KERNEL__ */
+
+
+/*
+ * Read a block from the journal
+ */
+
+static int jread(struct buffer_head **bhp, journal_t *journal,
+ unsigned int offset)
+{
+ int err;
+ unsigned long long blocknr;
+ struct buffer_head *bh;
+
+ *bhp = NULL;
+
+ if (offset >= journal->j_total_len) {
+ printk(KERN_ERR "JBD2: corrupted journal superblock\n");
+ return -EFSCORRUPTED;
+ }
+
+ err = jbd2_journal_bmap(journal, offset, &blocknr);
+
+ if (err) {
+ printk(KERN_ERR "JBD2: bad block at offset %u\n",
+ offset);
+ return err;
+ }
+
+ bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
+ if (!bh)
+ return -ENOMEM;
+
+ if (!buffer_uptodate(bh)) {
+ /*
+ * If this is a brand new buffer, start readahead.
+ * Otherwise, we assume we are already reading it.
+ */
+ bool need_readahead = !buffer_req(bh);
+
+ bh_read_nowait(bh, 0);
+ if (need_readahead)
+ do_readahead(journal, offset);
+ wait_on_buffer(bh);
+ }
+
+ if (!buffer_uptodate(bh)) {
+ printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
+ offset);
+ brelse(bh);
+ return -EIO;
+ }
+
+ *bhp = bh;
+ return 0;
+}
+
+static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
+{
+ struct jbd2_journal_block_tail *tail;
+ __be32 provided;
+ __u32 calculated;
+
+ if (!jbd2_journal_has_csum_v2or3(j))
+ return 1;
+
+ tail = (struct jbd2_journal_block_tail *)((char *)buf +
+ j->j_blocksize - sizeof(struct jbd2_journal_block_tail));
+ provided = tail->t_checksum;
+ tail->t_checksum = 0;
+ calculated = jbd2_chksum(j->j_csum_seed, buf, j->j_blocksize);
+ tail->t_checksum = provided;
+
+ return provided == cpu_to_be32(calculated);
+}
+
+/*
+ * Count the number of in-use tags in a journal descriptor block.
+ */
+
+static int count_tags(journal_t *journal, struct buffer_head *bh)
+{
+ char * tagp;
+ journal_block_tag_t tag;
+ int nr = 0, size = journal->j_blocksize;
+ int tag_bytes = journal_tag_bytes(journal);
+
+ if (jbd2_journal_has_csum_v2or3(journal))
+ size -= sizeof(struct jbd2_journal_block_tail);
+
+ tagp = &bh->b_data[sizeof(journal_header_t)];
+
+ while ((tagp - bh->b_data + tag_bytes) <= size) {
+ memcpy(&tag, tagp, sizeof(tag));
+
+ nr++;
+ tagp += tag_bytes;
+ if (!(tag.t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
+ tagp += 16;
+
+ if (tag.t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
+ break;
+ }
+
+ return nr;
+}
+
+
+/* Make sure we wrap around the log correctly! */
+#define wrap(journal, var) \
+do { \
+ if (var >= (journal)->j_last) \
+ var -= ((journal)->j_last - (journal)->j_first); \
+} while (0)
+
+static int fc_do_one_pass(journal_t *journal,
+ struct recovery_info *info, enum passtype pass)
+{
+ unsigned int expected_commit_id = info->end_transaction;
+ unsigned long next_fc_block;
+ struct buffer_head *bh;
+ int err = 0;
+
+ next_fc_block = journal->j_fc_first;
+ if (!journal->j_fc_replay_callback)
+ return 0;
+
+ while (next_fc_block <= journal->j_fc_last) {
+ jbd2_debug(3, "Fast commit replay: next block %ld\n",
+ next_fc_block);
+ err = jread(&bh, journal, next_fc_block);
+ if (err) {
+ jbd2_debug(3, "Fast commit replay: read error\n");
+ break;
+ }
+
+ err = journal->j_fc_replay_callback(journal, bh, pass,
+ next_fc_block - journal->j_fc_first,
+ expected_commit_id);
+ brelse(bh);
+ next_fc_block++;
+ if (err < 0 || err == JBD2_FC_REPLAY_STOP)
+ break;
+ err = 0;
+ }
+
+ if (err)
+ jbd2_debug(3, "Fast commit replay failed, err = %d\n", err);
+
+ return err;
+}
+
+/**
+ * jbd2_journal_recover - recovers a on-disk journal
+ * @journal: the journal to recover
+ *
+ * The primary function for recovering the log contents when mounting a
+ * journaled device.
+ *
+ * Recovery is done in three passes. In the first pass, we look for the
+ * end of the log. In the second, we assemble the list of revoke
+ * blocks. In the third and final pass, we replay any un-revoked blocks
+ * in the log.
+ */
+int jbd2_journal_recover(journal_t *journal)
+{
+ int err, err2;
+ struct recovery_info info;
+
+ memset(&info, 0, sizeof(info));
+
+ /*
+ * The journal superblock's s_start field (the current log head)
+ * is always zero if, and only if, the journal was cleanly
+ * unmounted. We use its in-memory version j_tail here because
+ * jbd2_journal_wipe() could have updated it without updating journal
+ * superblock.
+ */
+ if (!journal->j_tail) {
+ journal_superblock_t *sb = journal->j_superblock;
+
+ jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n",
+ be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head));
+ journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
+ journal->j_head = be32_to_cpu(sb->s_head);
+ return 0;
+ }
+
+ err = do_one_pass(journal, &info, PASS_SCAN);
+ if (!err)
+ err = do_one_pass(journal, &info, PASS_REVOKE);
+ if (!err)
+ err = do_one_pass(journal, &info, PASS_REPLAY);
+
+ jbd2_debug(1, "JBD2: recovery, exit status %d, "
+ "recovered transactions %u to %u\n",
+ err, info.start_transaction, info.end_transaction);
+ jbd2_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
+ info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
+
+ /* Restart the log at the next transaction ID, thus invalidating
+ * any existing commit records in the log. */
+ journal->j_transaction_sequence = ++info.end_transaction;
+ journal->j_head = info.head_block;
+ jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n",
+ journal->j_transaction_sequence, journal->j_head);
+
+ jbd2_journal_clear_revoke(journal);
+ /* Free revoke table allocated for replay */
+ if (journal->j_revoke != journal->j_revoke_table[0] &&
+ journal->j_revoke != journal->j_revoke_table[1]) {
+ jbd2_journal_destroy_revoke_table(journal->j_revoke);
+ journal->j_revoke = journal->j_revoke_table[1];
+ }
+ err2 = sync_blockdev(journal->j_fs_dev);
+ if (!err)
+ err = err2;
+ err2 = jbd2_check_fs_dev_write_error(journal);
+ if (!err)
+ err = err2;
+ /* Make sure all replayed data is on permanent storage */
+ if (journal->j_flags & JBD2_BARRIER) {
+ err2 = blkdev_issue_flush(journal->j_fs_dev);
+ if (!err)
+ err = err2;
+ }
+ return err;
+}
+
+/**
+ * jbd2_journal_skip_recovery - Start journal and wipe exiting records
+ * @journal: journal to startup
+ *
+ * Locate any valid recovery information from the journal and set up the
+ * journal structures in memory to ignore it (presumably because the
+ * caller has evidence that it is out of date).
+ * This function doesn't appear to be exported..
+ *
+ * We perform one pass over the journal to allow us to tell the user how
+ * much recovery information is being erased, and to let us initialise
+ * the journal transaction sequence numbers to the next unused ID.
+ */
+int jbd2_journal_skip_recovery(journal_t *journal)
+{
+ int err;
+
+ struct recovery_info info;
+
+ memset (&info, 0, sizeof(info));
+
+ err = do_one_pass(journal, &info, PASS_SCAN);
+
+ if (err) {
+ printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
+ ++journal->j_transaction_sequence;
+ journal->j_head = journal->j_first;
+ } else {
+#ifdef CONFIG_JBD2_DEBUG
+ int dropped = info.end_transaction -
+ be32_to_cpu(journal->j_superblock->s_sequence);
+ jbd2_debug(1,
+ "JBD2: ignoring %d transaction%s from the journal.\n",
+ dropped, str_plural(dropped));
+#endif
+ journal->j_transaction_sequence = ++info.end_transaction;
+ journal->j_head = info.head_block;
+ }
+
+ journal->j_tail = 0;
+ return err;
+}
+
+static inline unsigned long long read_tag_block(journal_t *journal,
+ journal_block_tag_t *tag)
+{
+ unsigned long long block = be32_to_cpu(tag->t_blocknr);
+ if (jbd2_has_feature_64bit(journal))
+ block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
+ 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 "JBD2: 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);
+ }
+ put_bh(obh);
+ }
+ return 0;
+}
+
+static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
+{
+ struct commit_header *h;
+ __be32 provided;
+ __u32 calculated;
+
+ if (!jbd2_journal_has_csum_v2or3(j))
+ return 1;
+
+ h = buf;
+ provided = h->h_chksum[0];
+ h->h_chksum[0] = 0;
+ calculated = jbd2_chksum(j->j_csum_seed, buf, j->j_blocksize);
+ h->h_chksum[0] = provided;
+
+ return provided == cpu_to_be32(calculated);
+}
+
+static bool jbd2_commit_block_csum_verify_partial(journal_t *j, void *buf)
+{
+ struct commit_header *h;
+ __be32 provided;
+ __u32 calculated;
+ void *tmpbuf;
+
+ tmpbuf = kzalloc(j->j_blocksize, GFP_KERNEL);
+ if (!tmpbuf)
+ return false;
+
+ memcpy(tmpbuf, buf, sizeof(struct commit_header));
+ h = tmpbuf;
+ provided = h->h_chksum[0];
+ h->h_chksum[0] = 0;
+ calculated = jbd2_chksum(j->j_csum_seed, tmpbuf, j->j_blocksize);
+ kfree(tmpbuf);
+
+ return provided == cpu_to_be32(calculated);
+}
+
+static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
+ journal_block_tag3_t *tag3,
+ void *buf, __u32 sequence)
+{
+ __u32 csum32;
+ __be32 seq;
+
+ if (!jbd2_journal_has_csum_v2or3(j))
+ return 1;
+
+ seq = cpu_to_be32(sequence);
+ csum32 = jbd2_chksum(j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
+ csum32 = jbd2_chksum(csum32, buf, j->j_blocksize);
+
+ if (jbd2_has_feature_csum3(j))
+ return tag3->t_checksum == cpu_to_be32(csum32);
+ else
+ return tag->t_checksum == cpu_to_be16(csum32);
+}
+
+static __always_inline int jbd2_do_replay(journal_t *journal,
+ struct recovery_info *info,
+ struct buffer_head *bh,
+ unsigned long *next_log_block,
+ unsigned int next_commit_ID)
+{
+ char *tagp;
+ int flags;
+ int ret = 0;
+ int tag_bytes = journal_tag_bytes(journal);
+ int descr_csum_size = 0;
+ unsigned long io_block;
+ journal_block_tag_t tag;
+ struct buffer_head *obh;
+ struct buffer_head *nbh;
+
+ if (jbd2_journal_has_csum_v2or3(journal))
+ descr_csum_size = sizeof(struct jbd2_journal_block_tail);
+
+ tagp = &bh->b_data[sizeof(journal_header_t)];
+ while (tagp - bh->b_data + tag_bytes <=
+ journal->j_blocksize - descr_csum_size) {
+ int err;
+
+ memcpy(&tag, tagp, sizeof(tag));
+ flags = be16_to_cpu(tag.t_flags);
+
+ io_block = (*next_log_block)++;
+ wrap(journal, *next_log_block);
+ err = jread(&obh, journal, io_block);
+ if (err) {
+ /* Recover what we can, but report failure at the end. */
+ ret = err;
+ pr_err("JBD2: IO error %d recovering block %lu in log\n",
+ err, io_block);
+ } else {
+ unsigned long long blocknr;
+
+ J_ASSERT(obh != NULL);
+ blocknr = read_tag_block(journal, &tag);
+
+ /* If the block has been revoked, then we're all done here. */
+ if (jbd2_journal_test_revoke(journal, blocknr,
+ next_commit_ID)) {
+ brelse(obh);
+ ++info->nr_revoke_hits;
+ goto skip_write;
+ }
+
+ /* Look for block corruption */
+ if (!jbd2_block_tag_csum_verify(journal, &tag,
+ (journal_block_tag3_t *)tagp,
+ obh->b_data, next_commit_ID)) {
+ brelse(obh);
+ ret = -EFSBADCRC;
+ pr_err("JBD2: Invalid checksum recovering data block %llu in journal block %lu\n",
+ blocknr, io_block);
+ goto skip_write;
+ }
+
+ /* Find a buffer for the new data being restored */
+ nbh = __getblk(journal->j_fs_dev, blocknr,
+ journal->j_blocksize);
+ if (nbh == NULL) {
+ pr_err("JBD2: Out of memory during recovery.\n");
+ brelse(obh);
+ return -ENOMEM;
+ }
+
+ lock_buffer(nbh);
+ memcpy(nbh->b_data, obh->b_data, journal->j_blocksize);
+ if (flags & JBD2_FLAG_ESCAPE) {
+ *((__be32 *)nbh->b_data) =
+ cpu_to_be32(JBD2_MAGIC_NUMBER);
+ }
+
+ BUFFER_TRACE(nbh, "marking dirty");
+ set_buffer_uptodate(nbh);
+ mark_buffer_dirty(nbh);
+ BUFFER_TRACE(nbh, "marking uptodate");
+ ++info->nr_replays;
+ unlock_buffer(nbh);
+ brelse(obh);
+ brelse(nbh);
+ }
+
+skip_write:
+ tagp += tag_bytes;
+ if (!(flags & JBD2_FLAG_SAME_UUID))
+ tagp += 16;
+
+ if (flags & JBD2_FLAG_LAST_TAG)
+ break;
+ }
+
+ return ret;
+}
+
+static int do_one_pass(journal_t *journal,
+ struct recovery_info *info, enum passtype pass)
+{
+ unsigned int first_commit_ID, next_commit_ID;
+ unsigned long next_log_block, head_block;
+ int err, success = 0;
+ journal_superblock_t * sb;
+ journal_header_t * tmp;
+ struct buffer_head *bh = NULL;
+ unsigned int sequence;
+ int blocktype;
+ __u32 crc32_sum = ~0; /* Transactional Checksums */
+ bool need_check_commit_time = false;
+ __u64 last_trans_commit_time = 0, commit_time;
+
+ /*
+ * First thing is to establish what we expect to find in the log
+ * (in terms of transaction IDs), and where (in terms of log
+ * block offsets): query the superblock.
+ */
+
+ sb = journal->j_superblock;
+ next_commit_ID = be32_to_cpu(sb->s_sequence);
+ next_log_block = be32_to_cpu(sb->s_start);
+ head_block = next_log_block;
+
+ first_commit_ID = next_commit_ID;
+ if (pass == PASS_SCAN)
+ info->start_transaction = first_commit_ID;
+ else if (pass == PASS_REVOKE) {
+ /*
+ * Would the default revoke table have too long hash chains
+ * during replay?
+ */
+ if (info->nr_revokes > JOURNAL_REVOKE_DEFAULT_HASH * 16) {
+ unsigned int hash_size;
+
+ /*
+ * Aim for average chain length of 8, limit at 1M
+ * entries to avoid problems with malicious
+ * filesystems.
+ */
+ hash_size = min(roundup_pow_of_two(info->nr_revokes / 8),
+ 1U << 20);
+ journal->j_revoke =
+ jbd2_journal_init_revoke_table(hash_size);
+ if (!journal->j_revoke) {
+ printk(KERN_ERR
+ "JBD2: failed to allocate revoke table for replay with %u entries. "
+ "Journal replay may be slow.\n", hash_size);
+ journal->j_revoke = journal->j_revoke_table[1];
+ }
+ }
+ }
+
+ jbd2_debug(1, "Starting recovery pass %d\n", pass);
+
+ /*
+ * Now we walk through the log, transaction by transaction,
+ * making sure that each transaction has a commit block in the
+ * expected place. Each complete transaction gets replayed back
+ * into the main filesystem.
+ */
+
+ while (1) {
+ cond_resched();
+
+ /* If we already know where to stop the log traversal,
+ * check right now that we haven't gone past the end of
+ * the log. */
+
+ if (pass != PASS_SCAN)
+ if (tid_geq(next_commit_ID, info->end_transaction))
+ break;
+
+ jbd2_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
+ next_commit_ID, next_log_block, journal->j_last);
+
+ /* Skip over each chunk of the transaction looking
+ * either the next descriptor block or the final commit
+ * record. */
+
+ jbd2_debug(3, "JBD2: checking block %ld\n", next_log_block);
+ brelse(bh);
+ bh = NULL;
+ err = jread(&bh, journal, next_log_block);
+ if (err)
+ goto failed;
+
+ next_log_block++;
+ wrap(journal, next_log_block);
+
+ /* What kind of buffer is it?
+ *
+ * If it is a descriptor block, check that it has the
+ * expected sequence number. Otherwise, we're all done
+ * here. */
+
+ tmp = (journal_header_t *)bh->b_data;
+
+ if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER))
+ break;
+
+ blocktype = be32_to_cpu(tmp->h_blocktype);
+ sequence = be32_to_cpu(tmp->h_sequence);
+ jbd2_debug(3, "Found magic %d, sequence %d\n",
+ blocktype, sequence);
+
+ if (sequence != next_commit_ID)
+ break;
+
+ /* OK, we have a valid descriptor block which matches
+ * all of the sequence number checks. What are we going
+ * to do with it? That depends on the pass... */
+
+ switch(blocktype) {
+ case JBD2_DESCRIPTOR_BLOCK:
+ /* Verify checksum first */
+ if (!jbd2_descriptor_block_csum_verify(journal,
+ bh->b_data)) {
+ /*
+ * PASS_SCAN can see stale blocks due to lazy
+ * journal init. Don't error out on those yet.
+ */
+ if (pass != PASS_SCAN) {
+ pr_err("JBD2: Invalid checksum recovering block %lu in log\n",
+ next_log_block);
+ err = -EFSBADCRC;
+ goto failed;
+ }
+ need_check_commit_time = true;
+ jbd2_debug(1,
+ "invalid descriptor block found in %lu\n",
+ next_log_block);
+ }
+
+ /* If it is a valid descriptor block, replay it
+ * 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_feature_checksum(journal) &&
+ !info->end_transaction) {
+ if (calc_chksums(journal, bh,
+ &next_log_block,
+ &crc32_sum))
+ break;
+ continue;
+ }
+ next_log_block += count_tags(journal, bh);
+ wrap(journal, next_log_block);
+ continue;
+ }
+
+ /*
+ * A descriptor block: we can now write all of the
+ * data blocks. Yay, useful work is finally getting
+ * done here!
+ */
+ err = jbd2_do_replay(journal, info, bh, &next_log_block,
+ next_commit_ID);
+ if (err) {
+ if (err == -ENOMEM)
+ goto failed;
+ success = err;
+ }
+
+ continue;
+
+ case JBD2_COMMIT_BLOCK:
+ if (pass != PASS_SCAN) {
+ next_commit_ID++;
+ continue;
+ }
+
+ /* 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".)
+ */
+ commit_time = be64_to_cpu(
+ ((struct commit_header *)bh->b_data)->h_commit_sec);
+ /*
+ * If need_check_commit_time is set, it means we are in
+ * PASS_SCAN and csum verify failed before. If
+ * commit_time is increasing, it's the same journal,
+ * otherwise it is stale journal block, just end this
+ * recovery.
+ */
+ if (need_check_commit_time) {
+ if (commit_time >= last_trans_commit_time) {
+ pr_err("JBD2: Invalid checksum found in transaction %u\n",
+ next_commit_ID);
+ err = -EFSBADCRC;
+ goto failed;
+ }
+ ignore_crc_mismatch:
+ /*
+ * It likely does not belong to same journal,
+ * just end this recovery with success.
+ */
+ jbd2_debug(1, "JBD2: Invalid checksum ignored in transaction %u, likely stale data\n",
+ next_commit_ID);
+ goto done;
+ }
+
+ /*
+ * 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 (jbd2_has_feature_checksum(journal)) {
+ struct commit_header *cbh =
+ (struct commit_header *)bh->b_data;
+ unsigned found_chksum =
+ be32_to_cpu(cbh->h_chksum[0]);
+
+ if (info->end_transaction) {
+ journal->j_failed_commit =
+ info->end_transaction;
+ break;
+ }
+
+ /* Neither checksum match nor unused? */
+ if (!((crc32_sum == found_chksum &&
+ cbh->h_chksum_type ==
+ JBD2_CRC32_CHKSUM &&
+ cbh->h_chksum_size ==
+ JBD2_CRC32_CHKSUM_SIZE) ||
+ (cbh->h_chksum_type == 0 &&
+ cbh->h_chksum_size == 0 &&
+ found_chksum == 0)))
+ goto chksum_error;
+
+ crc32_sum = ~0;
+ goto chksum_ok;
+ }
+
+ if (jbd2_commit_block_csum_verify(journal, bh->b_data))
+ goto chksum_ok;
+
+ if (jbd2_commit_block_csum_verify_partial(journal,
+ bh->b_data)) {
+ pr_notice("JBD2: Find incomplete commit block in transaction %u block %lu\n",
+ next_commit_ID, next_log_block);
+ goto chksum_ok;
+ }
+
+chksum_error:
+ if (commit_time < last_trans_commit_time)
+ goto ignore_crc_mismatch;
+ info->end_transaction = next_commit_ID;
+ info->head_block = head_block;
+
+ if (!jbd2_has_feature_async_commit(journal)) {
+ journal->j_failed_commit = next_commit_ID;
+ break;
+ }
+
+chksum_ok:
+ last_trans_commit_time = commit_time;
+ head_block = next_log_block;
+ next_commit_ID++;
+ continue;
+
+ case JBD2_REVOKE_BLOCK:
+ /*
+ * If we aren't in the SCAN or REVOKE pass, then we can
+ * just skip over this block.
+ */
+ if (pass != PASS_REVOKE && pass != PASS_SCAN)
+ continue;
+
+ /*
+ * Check revoke block crc in pass_scan, if csum verify
+ * failed, check commit block time later.
+ */
+ if (pass == PASS_SCAN &&
+ !jbd2_descriptor_block_csum_verify(journal,
+ bh->b_data)) {
+ jbd2_debug(1, "JBD2: invalid revoke block found in %lu\n",
+ next_log_block);
+ need_check_commit_time = true;
+ }
+
+ err = scan_revoke_records(journal, pass, bh,
+ next_commit_ID, info);
+ if (err)
+ goto failed;
+ continue;
+
+ default:
+ jbd2_debug(3, "Unrecognised magic %d, end of scan.\n",
+ blocktype);
+ goto done;
+ }
+ }
+
+ done:
+ brelse(bh);
+ /*
+ * We broke out of the log scan loop: either we came to the
+ * known end of the log or we found an unexpected block in the
+ * log. If the latter happened, then we know that the "current"
+ * transaction marks the end of the valid log.
+ */
+
+ if (pass == PASS_SCAN) {
+ if (!info->end_transaction)
+ info->end_transaction = next_commit_ID;
+ if (!info->head_block)
+ info->head_block = head_block;
+ } 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) {
+ printk(KERN_ERR "JBD2: recovery pass %d ended at "
+ "transaction %u, expected %u\n",
+ pass, next_commit_ID, info->end_transaction);
+ if (!success)
+ success = -EIO;
+ }
+ }
+
+ if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE) {
+ err = fc_do_one_pass(journal, info, pass);
+ if (err)
+ success = err;
+ }
+
+ return success;
+
+ failed:
+ brelse(bh);
+ return err;
+}
+
+/* Scan a revoke record, marking all blocks mentioned as revoked. */
+
+static int scan_revoke_records(journal_t *journal, enum passtype pass,
+ struct buffer_head *bh, tid_t sequence,
+ struct recovery_info *info)
+{
+ jbd2_journal_revoke_header_t *header;
+ int offset, max;
+ unsigned csum_size = 0;
+ __u32 rcount;
+ int record_len = 4;
+
+ header = (jbd2_journal_revoke_header_t *) bh->b_data;
+ offset = sizeof(jbd2_journal_revoke_header_t);
+ rcount = be32_to_cpu(header->r_count);
+
+ if (jbd2_journal_has_csum_v2or3(journal))
+ csum_size = sizeof(struct jbd2_journal_block_tail);
+ if (rcount > journal->j_blocksize - csum_size)
+ return -EINVAL;
+ max = rcount;
+
+ if (jbd2_has_feature_64bit(journal))
+ record_len = 8;
+
+ if (pass == PASS_SCAN) {
+ info->nr_revokes += (max - offset) / record_len;
+ return 0;
+ }
+
+ while (offset + record_len <= max) {
+ unsigned long long blocknr;
+ int err;
+
+ if (record_len == 4)
+ blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
+ else
+ blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
+ offset += record_len;
+ err = jbd2_journal_set_revoke(journal, blocknr, sequence);
+ if (err)
+ return err;
+ }
+ return 0;
+}