diff options
Diffstat (limited to 'fs/jbd/commit.c')
| -rw-r--r-- | fs/jbd/commit.c | 1021 |
1 files changed, 0 insertions, 1021 deletions
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c deleted file mode 100644 index bb217dcb41af..000000000000 --- a/fs/jbd/commit.c +++ /dev/null @@ -1,1021 +0,0 @@ -/* - * linux/fs/jbd/commit.c - * - * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 - * - * Copyright 1998 Red Hat corp --- All Rights Reserved - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. - * - * 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/jbd.h> -#include <linux/errno.h> -#include <linux/mm.h> -#include <linux/pagemap.h> -#include <linux/bio.h> -#include <linux/blkdev.h> -#include <trace/events/jbd.h> - -/* - * Default IO end handler for temporary BJ_IO buffer_heads. - */ -static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate) -{ - BUFFER_TRACE(bh, ""); - if (uptodate) - set_buffer_uptodate(bh); - else - clear_buffer_uptodate(bh); - unlock_buffer(bh); -} - -/* - * When an ext3-ordered file is truncated, it is possible that many 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 journal->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 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; - - page_cache_get(page); - __brelse(bh); - try_to_free_buffers(page); - unlock_page(page); - page_cache_release(page); - return; - -nope: - __brelse(bh); -} - -/* - * Decrement reference counter for data buffer. If it has been marked - * 'BH_Freed', release it and the page to which it belongs if possible. - */ -static void release_data_buffer(struct buffer_head *bh) -{ - if (buffer_freed(bh)) { - WARN_ON_ONCE(buffer_dirty(bh)); - clear_buffer_freed(bh); - clear_buffer_mapped(bh); - clear_buffer_new(bh); - clear_buffer_req(bh); - bh->b_bdev = NULL; - release_buffer_page(bh); - } else - put_bh(bh); -} - -/* - * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is - * held. For ranking reasons we must trylock. If we lose, schedule away and - * return 0. j_list_lock is dropped in this case. - */ -static int inverted_lock(journal_t *journal, struct buffer_head *bh) -{ - if (!jbd_trylock_bh_state(bh)) { - spin_unlock(&journal->j_list_lock); - schedule(); - return 0; - } - return 1; -} - -/* Done it all: now write the commit record. We should have - * cleaned up our previous buffers by now, so if we are in abort - * mode we can now just skip the rest of the journal write - * entirely. - * - * Returns 1 if the journal needs to be aborted or 0 on success - */ -static int journal_write_commit_record(journal_t *journal, - transaction_t *commit_transaction) -{ - struct journal_head *descriptor; - struct buffer_head *bh; - journal_header_t *header; - int ret; - - if (is_journal_aborted(journal)) - return 0; - - descriptor = journal_get_descriptor_buffer(journal); - if (!descriptor) - return 1; - - bh = jh2bh(descriptor); - - header = (journal_header_t *)(bh->b_data); - header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); - header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK); - header->h_sequence = cpu_to_be32(commit_transaction->t_tid); - - JBUFFER_TRACE(descriptor, "write commit block"); - set_buffer_dirty(bh); - - if (journal->j_flags & JFS_BARRIER) - ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA); - else - ret = sync_dirty_buffer(bh); - - put_bh(bh); /* One for getblk() */ - journal_put_journal_head(descriptor); - - return (ret == -EIO); -} - -static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, - int write_op) -{ - int i; - - for (i = 0; i < bufs; i++) { - wbuf[i]->b_end_io = end_buffer_write_sync; - /* - * Here we write back pagecache data that may be mmaped. Since - * we cannot afford to clean the page and set PageWriteback - * here due to lock ordering (page lock ranks above transaction - * start), the data can change while IO is in flight. Tell the - * block layer it should bounce the bio pages if stable data - * during write is required. - * - * We use up our safety reference in submit_bh(). - */ - _submit_bh(write_op, wbuf[i], 1 << BIO_SNAP_STABLE); - } -} - -/* - * Submit all the data buffers to disk - */ -static int journal_submit_data_buffers(journal_t *journal, - transaction_t *commit_transaction, - int write_op) -{ - struct journal_head *jh; - struct buffer_head *bh; - int locked; - int bufs = 0; - struct buffer_head **wbuf = journal->j_wbuf; - int err = 0; - - /* - * Whenever we unlock the journal and sleep, things can get added - * onto ->t_sync_datalist, so we have to keep looping back to - * write_out_data until we *know* that the list is empty. - * - * Cleanup any flushed data buffers from the data list. Even in - * abort mode, we want to flush this out as soon as possible. - */ -write_out_data: - cond_resched(); - spin_lock(&journal->j_list_lock); - - while (commit_transaction->t_sync_datalist) { - jh = commit_transaction->t_sync_datalist; - bh = jh2bh(jh); - locked = 0; - - /* Get reference just to make sure buffer does not disappear - * when we are forced to drop various locks */ - get_bh(bh); - /* If the buffer is dirty, we need to submit IO and hence - * we need the buffer lock. We try to lock the buffer without - * blocking. If we fail, we need to drop j_list_lock and do - * blocking lock_buffer(). - */ - if (buffer_dirty(bh)) { - if (!trylock_buffer(bh)) { - BUFFER_TRACE(bh, "needs blocking lock"); - spin_unlock(&journal->j_list_lock); - trace_jbd_do_submit_data(journal, - commit_transaction); - /* Write out all data to prevent deadlocks */ - journal_do_submit_data(wbuf, bufs, write_op); - bufs = 0; - lock_buffer(bh); - spin_lock(&journal->j_list_lock); - } - locked = 1; - } - /* We have to get bh_state lock. Again out of order, sigh. */ - if (!inverted_lock(journal, bh)) { - jbd_lock_bh_state(bh); - spin_lock(&journal->j_list_lock); - } - /* Someone already cleaned up the buffer? */ - if (!buffer_jbd(bh) || bh2jh(bh) != jh - || jh->b_transaction != commit_transaction - || jh->b_jlist != BJ_SyncData) { - jbd_unlock_bh_state(bh); - if (locked) - unlock_buffer(bh); - BUFFER_TRACE(bh, "already cleaned up"); - release_data_buffer(bh); - continue; - } - if (locked && test_clear_buffer_dirty(bh)) { - BUFFER_TRACE(bh, "needs writeout, adding to array"); - wbuf[bufs++] = bh; - __journal_file_buffer(jh, commit_transaction, - BJ_Locked); - jbd_unlock_bh_state(bh); - if (bufs == journal->j_wbufsize) { - spin_unlock(&journal->j_list_lock); - trace_jbd_do_submit_data(journal, - commit_transaction); - journal_do_submit_data(wbuf, bufs, write_op); - bufs = 0; - goto write_out_data; - } - } else if (!locked && buffer_locked(bh)) { - __journal_file_buffer(jh, commit_transaction, - BJ_Locked); - jbd_unlock_bh_state(bh); - put_bh(bh); - } else { - BUFFER_TRACE(bh, "writeout complete: unfile"); - if (unlikely(!buffer_uptodate(bh))) - err = -EIO; - __journal_unfile_buffer(jh); - jbd_unlock_bh_state(bh); - if (locked) - unlock_buffer(bh); - release_data_buffer(bh); - } - - if (need_resched() || spin_needbreak(&journal->j_list_lock)) { - spin_unlock(&journal->j_list_lock); - goto write_out_data; - } - } - spin_unlock(&journal->j_list_lock); - trace_jbd_do_submit_data(journal, commit_transaction); - journal_do_submit_data(wbuf, bufs, write_op); - - return err; -} - -/* - * 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 journal_commit_transaction(journal_t *journal) -{ - transaction_t *commit_transaction; - struct journal_head *jh, *new_jh, *descriptor; - struct buffer_head **wbuf = journal->j_wbuf; - int bufs; - int flags; - int err; - unsigned int blocknr; - ktime_t start_time; - u64 commit_time; - char *tagp = NULL; - journal_header_t *header; - journal_block_tag_t *tag = NULL; - int space_left = 0; - int first_tag = 0; - int tag_flag; - int i; - struct blk_plug plug; - int write_op = WRITE; - - /* - * 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 journal_flush? */ - if (journal->j_flags & JFS_FLUSHED) { - jbd_debug(3, "super block updated\n"); - mutex_lock(&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. - */ - journal_update_sb_log_tail(journal, journal->j_tail_sequence, - journal->j_tail, WRITE_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); - - commit_transaction = journal->j_running_transaction; - - trace_jbd_start_commit(journal, commit_transaction); - jbd_debug(1, "JBD: starting commit of transaction %d\n", - commit_transaction->t_tid); - - spin_lock(&journal->j_state_lock); - J_ASSERT(commit_transaction->t_state == T_RUNNING); - commit_transaction->t_state = T_LOCKED; - - trace_jbd_commit_locking(journal, commit_transaction); - spin_lock(&commit_transaction->t_handle_lock); - while (commit_transaction->t_updates) { - DEFINE_WAIT(wait); - - prepare_to_wait(&journal->j_wait_updates, &wait, - TASK_UNINTERRUPTIBLE); - if (commit_transaction->t_updates) { - spin_unlock(&commit_transaction->t_handle_lock); - spin_unlock(&journal->j_state_lock); - schedule(); - spin_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); - - J_ASSERT (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 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 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 journal_get_undo_access()+journal_release_buffer() may - * leave undo-committed data. - */ - if (jh->b_committed_data) { - struct buffer_head *bh = jh2bh(jh); - - jbd_lock_bh_state(bh); - jbd_free(jh->b_committed_data, bh->b_size); - jh->b_committed_data = NULL; - jbd_unlock_bh_state(bh); - } - 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); - __journal_clean_checkpoint_list(journal); - spin_unlock(&journal->j_list_lock); - - jbd_debug (3, "JBD: commit phase 1\n"); - - /* - * Clear revoked flag to reflect there is no revoked buffers - * in the next transaction which is going to be started. - */ - journal_clear_buffer_revoked_flags(journal); - - /* - * Switch to a new revoke table. - */ - journal_switch_revoke_table(journal); - - trace_jbd_commit_flushing(journal, commit_transaction); - 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); - spin_unlock(&journal->j_state_lock); - - jbd_debug (3, "JBD: commit phase 2\n"); - - if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid)) - write_op = WRITE_SYNC; - - /* - * Now start flushing things to disk, in the order they appear - * on the transaction lists. Data blocks go first. - */ - blk_start_plug(&plug); - err = journal_submit_data_buffers(journal, commit_transaction, - write_op); - blk_finish_plug(&plug); - - /* - * Wait for all previously submitted IO to complete. - */ - spin_lock(&journal->j_list_lock); - while (commit_transaction->t_locked_list) { - struct buffer_head *bh; - - jh = commit_transaction->t_locked_list->b_tprev; - bh = jh2bh(jh); - get_bh(bh); - if (buffer_locked(bh)) { - spin_unlock(&journal->j_list_lock); - wait_on_buffer(bh); - spin_lock(&journal->j_list_lock); - } - if (unlikely(!buffer_uptodate(bh))) { - if (!trylock_page(bh->b_page)) { - spin_unlock(&journal->j_list_lock); - lock_page(bh->b_page); - spin_lock(&journal->j_list_lock); - } - if (bh->b_page->mapping) - set_bit(AS_EIO, &bh->b_page->mapping->flags); - - unlock_page(bh->b_page); - SetPageError(bh->b_page); - err = -EIO; - } - if (!inverted_lock(journal, bh)) { - put_bh(bh); - spin_lock(&journal->j_list_lock); - continue; - } - if (buffer_jbd(bh) && bh2jh(bh) == jh && - jh->b_transaction == commit_transaction && - jh->b_jlist == BJ_Locked) - __journal_unfile_buffer(jh); - jbd_unlock_bh_state(bh); - release_data_buffer(bh); - cond_resched_lock(&journal->j_list_lock); - } - spin_unlock(&journal->j_list_lock); - - if (err) { - char b[BDEVNAME_SIZE]; - - printk(KERN_WARNING - "JBD: Detected IO errors while flushing file data " - "on %s\n", bdevname(journal->j_fs_dev, b)); - if (journal->j_flags & JFS_ABORT_ON_SYNCDATA_ERR) - journal_abort(journal, err); - err = 0; - } - - blk_start_plug(&plug); - - journal_write_revoke_records(journal, commit_transaction, write_op); - - /* - * If we found any dirty or locked buffers, then we should have - * looped back up to the write_out_data label. If there weren't - * any then journal_clean_data_list should have wiped the list - * clean by now, so check that it is in fact empty. - */ - J_ASSERT (commit_transaction->t_sync_datalist == NULL); - - jbd_debug (3, "JBD: commit phase 3\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: - */ - spin_lock(&journal->j_state_lock); - commit_transaction->t_state = T_COMMIT; - spin_unlock(&journal->j_state_lock); - - trace_jbd_commit_logging(journal, commit_transaction); - J_ASSERT(commit_transaction->t_nr_buffers <= - commit_transaction->t_outstanding_credits); - - descriptor = NULL; - bufs = 0; - 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"); - 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) { - struct buffer_head *bh; - - J_ASSERT (bufs == 0); - - jbd_debug(4, "JBD: get descriptor\n"); - - descriptor = journal_get_descriptor_buffer(journal); - if (!descriptor) { - journal_abort(journal, -EIO); - continue; - } - - bh = jh2bh(descriptor); - jbd_debug(4, "JBD: got buffer %llu (%p)\n", - (unsigned long long)bh->b_blocknr, bh->b_data); - header = (journal_header_t *)&bh->b_data[0]; - header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); - header->h_blocktype = cpu_to_be32(JFS_DESCRIPTOR_BLOCK); - header->h_sequence = cpu_to_be32(commit_transaction->t_tid); - - tagp = &bh->b_data[sizeof(journal_header_t)]; - space_left = bh->b_size - sizeof(journal_header_t); - first_tag = 1; - set_buffer_jwrite(bh); - set_buffer_dirty(bh); - wbuf[bufs++] = bh; - - /* Record it so that we can wait for IO - completion later */ - BUFFER_TRACE(bh, "ph3: file as descriptor"); - journal_file_buffer(descriptor, commit_transaction, - BJ_LogCtl); - } - - /* Where is the buffer to be written? */ - - err = 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) { - journal_abort(journal, err); - continue; - } - - /* - * start_this_handle() uses t_outstanding_credits to determine - * the free space in the log, but this counter is changed - * by journal_next_log_block() also. - */ - 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 BJ_IO/BJ_Shadow pairing of buffers. */ - get_bh(jh2bh(jh)); - - /* Make a temporary IO buffer with which to write it out - (this will requeue both the metadata buffer and the - temporary IO buffer). new_bh goes on BJ_IO*/ - - set_buffer_jwrite(jh2bh(jh)); - /* - * akpm: journal_write_metadata_buffer() sets - * new_bh->b_transaction to commit_transaction. - * We need to clean this up before we release new_bh - * (which is of type BJ_IO) - */ - JBUFFER_TRACE(jh, "ph3: write metadata"); - flags = journal_write_metadata_buffer(commit_transaction, - jh, &new_jh, blocknr); - set_buffer_jwrite(jh2bh(new_jh)); - wbuf[bufs++] = jh2bh(new_jh); - - /* Record the new block's tag in the current descriptor - buffer */ - - tag_flag = 0; - if (flags & 1) - tag_flag |= JFS_FLAG_ESCAPE; - if (!first_tag) - tag_flag |= JFS_FLAG_SAME_UUID; - - tag = (journal_block_tag_t *) tagp; - tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr); - tag->t_flags = cpu_to_be32(tag_flag); - tagp += sizeof(journal_block_tag_t); - space_left -= sizeof(journal_block_tag_t); - - 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 < sizeof(journal_block_tag_t) + 16) { - - jbd_debug(4, "JBD: 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_be32(JFS_FLAG_LAST_TAG); - -start_journal_io: - for (i = 0; i < bufs; i++) { - struct buffer_head *bh = wbuf[i]; - lock_buffer(bh); - clear_buffer_dirty(bh); - set_buffer_uptodate(bh); - bh->b_end_io = journal_end_buffer_io_sync; - /* - * In data=journal mode, here we can end up - * writing pagecache data that might be - * mmapped. Since we can't afford to clean the - * page and set PageWriteback (see the comment - * near the other use of _submit_bh()), the - * data can change while the write is in - * flight. Tell the block layer to bounce the - * bio pages if stable pages are required. - */ - _submit_bh(write_op, bh, 1 << BIO_SNAP_STABLE); - } - cond_resched(); - - /* Force a new descriptor to be generated next - time round the loop. */ - descriptor = NULL; - bufs = 0; - } - } - - 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 t_iobuf_list queue. - - 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, "JBD: commit phase 4\n"); - - /* - * akpm: these are BJ_IO, and j_list_lock is not needed. - * See __journal_try_to_free_buffer. - */ -wait_for_iobuf: - while (commit_transaction->t_iobuf_list != NULL) { - struct buffer_head *bh; - - jh = commit_transaction->t_iobuf_list->b_tprev; - bh = jh2bh(jh); - if (buffer_locked(bh)) { - wait_on_buffer(bh); - goto wait_for_iobuf; - } - if (cond_resched()) - goto wait_for_iobuf; - - if (unlikely(!buffer_uptodate(bh))) - err = -EIO; - - clear_buffer_jwrite(bh); - - JBUFFER_TRACE(jh, "ph4: unfile after journal write"); - journal_unfile_buffer(journal, jh); - - /* - * ->t_iobuf_list should contain only dummy buffer_heads - * which were created by journal_write_metadata_buffer(). - */ - BUFFER_TRACE(bh, "dumping temporary bh"); - journal_put_journal_head(jh); - __brelse(bh); - J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); - free_buffer_head(bh); - - /* We also have to unlock and free 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)); - - /* 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"); - journal_file_buffer(jh, commit_transaction, BJ_Forget); - /* - * Wake up any transactions which were waiting for this - * IO to complete. The barrier must be here so that changes - * by journal_file_buffer() take effect before wake_up_bit() - * does the waitqueue check. - */ - smp_mb(); - wake_up_bit(&bh->b_state, BH_Unshadow); - JBUFFER_TRACE(jh, "brelse shadowed buffer"); - __brelse(bh); - } - - J_ASSERT (commit_transaction->t_shadow_list == NULL); - - jbd_debug(3, "JBD: commit phase 5\n"); - - /* Here we wait for the revoke record and descriptor record buffers */ - wait_for_ctlbuf: - while (commit_transaction->t_log_list != NULL) { - struct buffer_head *bh; - - jh = commit_transaction->t_log_list->b_tprev; - bh = jh2bh(jh); - if (buffer_locked(bh)) { - wait_on_buffer(bh); - goto wait_for_ctlbuf; - } - if (cond_resched()) - goto wait_for_ctlbuf; - - if (unlikely(!buffer_uptodate(bh))) - err = -EIO; - - BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); - clear_buffer_jwrite(bh); - journal_unfile_buffer(journal, jh); - journal_put_journal_head(jh); - __brelse(bh); /* One for getblk */ - /* AKPM: bforget here */ - } - - if (err) - journal_abort(journal, err); - - jbd_debug(3, "JBD: commit phase 6\n"); - - /* All metadata is written, now write commit record and do cleanup */ - spin_lock(&journal->j_state_lock); - J_ASSERT(commit_transaction->t_state == T_COMMIT); - commit_transaction->t_state = T_COMMIT_RECORD; - spin_unlock(&journal->j_state_lock); - - if (journal_write_commit_record(journal, commit_transaction)) - err = -EIO; - - if (err) - journal_abort(journal, err); - - /* 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, "JBD: commit phase 7\n"); - - J_ASSERT(commit_transaction->t_sync_datalist == NULL); - J_ASSERT(commit_transaction->t_buffers == NULL); - J_ASSERT(commit_transaction->t_checkpoint_list == NULL); - J_ASSERT(commit_transaction->t_iobuf_list == NULL); - J_ASSERT(commit_transaction->t_shadow_list == NULL); - J_ASSERT(commit_transaction->t_log_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; - - 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); - jbd_lock_bh_state(bh); - J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || - jh->b_transaction == journal->j_running_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. - */ - if (jh->b_committed_data) { - jbd_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; - } - } else if (jh->b_frozen_data) { - jbd_free(jh->b_frozen_data, bh->b_size); - jh->b_frozen_data = NULL; - } - - spin_lock(&journal->j_list_lock); - cp_transaction = jh->b_cp_transaction; - if (cp_transaction) { - JBUFFER_TRACE(jh, "remove from old cp transaction"); - __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 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. - */ - if (buffer_freed(bh)) { - /* - * If the running transaction is the one containing - * "add to orphan" operation (b_next_transaction != - * NULL), we have to wait for that transaction to - * commit before we can really get rid of the buffer. - * So just clear b_modified to not confuse transaction - * credit accounting and 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 throughout in that since the - * buffer may be still accessible when blocksize < - * pagesize and it is attached to the last partial - * page. - */ - jh->b_modified = 0; - if (!jh->b_next_transaction) { - clear_buffer_freed(bh); - clear_buffer_jbddirty(bh); - 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"); - __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 freed buffer"); - __journal_refile_buffer(jh); - jbd_unlock_bh_state(bh); - if (try_to_free) - release_buffer_page(bh); - 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 - * __journal_drop_transaction(). Otherwise we could race with - * other checkpointing code processing the transaction... - */ - spin_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); - spin_unlock(&journal->j_state_lock); - goto restart_loop; - } - - /* Done with this transaction! */ - - jbd_debug(3, "JBD: commit phase 8\n"); - - J_ASSERT(commit_transaction->t_state == T_COMMIT_RECORD); - - commit_transaction->t_state = T_FINISHED; - 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 commit time - */ - if (likely(journal->j_average_commit_time)) - journal->j_average_commit_time = (commit_time*3 + - journal->j_average_commit_time) / 4; - else - journal->j_average_commit_time = commit_time; - - spin_unlock(&journal->j_state_lock); - - if (commit_transaction->t_checkpoint_list == NULL && - commit_transaction->t_checkpoint_io_list == NULL) { - __journal_drop_transaction(journal, commit_transaction); - } else { - 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); - - trace_jbd_end_commit(journal, commit_transaction); - jbd_debug(1, "JBD: commit %d complete, head %d\n", - journal->j_commit_sequence, journal->j_tail_sequence); - - wake_up(&journal->j_wait_done_commit); -} |