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![Jens Axboe](/assets/img/avatar_default.png)
'write_op' was still used, even though it was always WRITE_SYNC now. Add plugging around the cases where it submits IO, and flush them before we end up waiting for that IO. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
1035 lines
31 KiB
C
1035 lines
31 KiB
C
/*
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* linux/fs/jbd2/commit.c
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*
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* Written by Stephen C. Tweedie <sct@redhat.com>, 1998
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*
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* Copyright 1998 Red Hat corp --- All Rights Reserved
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*
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* This file is part of the Linux kernel and is made available under
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* the terms of the GNU General Public License, version 2, or at your
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* option, any later version, incorporated herein by reference.
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*
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* Journal commit routines for the generic filesystem journaling code;
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* part of the ext2fs journaling system.
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*/
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/jbd2.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/jiffies.h>
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#include <linux/crc32.h>
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#include <linux/writeback.h>
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#include <linux/backing-dev.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/bitops.h>
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#include <trace/events/jbd2.h>
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#include <asm/system.h>
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/*
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* Default IO end handler for temporary BJ_IO buffer_heads.
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*/
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static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
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{
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BUFFER_TRACE(bh, "");
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if (uptodate)
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set_buffer_uptodate(bh);
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else
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clear_buffer_uptodate(bh);
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unlock_buffer(bh);
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}
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/*
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* When an ext4 file is truncated, it is possible that some pages are not
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* successfully freed, because they are attached to a committing transaction.
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* After the transaction commits, these pages are left on the LRU, with no
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* ->mapping, and with attached buffers. These pages are trivially reclaimable
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* by the VM, but their apparent absence upsets the VM accounting, and it makes
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* the numbers in /proc/meminfo look odd.
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*
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* So here, we have a buffer which has just come off the forget list. Look to
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* see if we can strip all buffers from the backing page.
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*
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* Called under lock_journal(), and possibly under journal_datalist_lock. The
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* caller provided us with a ref against the buffer, and we drop that here.
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*/
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static void release_buffer_page(struct buffer_head *bh)
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{
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struct page *page;
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if (buffer_dirty(bh))
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goto nope;
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if (atomic_read(&bh->b_count) != 1)
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goto nope;
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page = bh->b_page;
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if (!page)
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goto nope;
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if (page->mapping)
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goto nope;
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/* OK, it's a truncated page */
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if (!trylock_page(page))
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goto nope;
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page_cache_get(page);
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__brelse(bh);
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try_to_free_buffers(page);
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unlock_page(page);
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page_cache_release(page);
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return;
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nope:
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__brelse(bh);
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}
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/*
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* Done it all: now submit the commit record. We should have
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* cleaned up our previous buffers by now, so if we are in abort
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* mode we can now just skip the rest of the journal write
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* entirely.
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*
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* Returns 1 if the journal needs to be aborted or 0 on success
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*/
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static int journal_submit_commit_record(journal_t *journal,
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transaction_t *commit_transaction,
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struct buffer_head **cbh,
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__u32 crc32_sum)
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{
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struct journal_head *descriptor;
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struct commit_header *tmp;
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struct buffer_head *bh;
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int ret;
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struct timespec now = current_kernel_time();
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if (is_journal_aborted(journal))
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return 0;
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descriptor = jbd2_journal_get_descriptor_buffer(journal);
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if (!descriptor)
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return 1;
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bh = jh2bh(descriptor);
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tmp = (struct commit_header *)bh->b_data;
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tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
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tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
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tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
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tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
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tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
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if (JBD2_HAS_COMPAT_FEATURE(journal,
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JBD2_FEATURE_COMPAT_CHECKSUM)) {
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tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
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tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
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tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
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}
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JBUFFER_TRACE(descriptor, "submit commit block");
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lock_buffer(bh);
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clear_buffer_dirty(bh);
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set_buffer_uptodate(bh);
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bh->b_end_io = journal_end_buffer_io_sync;
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if (journal->j_flags & JBD2_BARRIER &&
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!JBD2_HAS_INCOMPAT_FEATURE(journal,
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JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
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ret = submit_bh(WRITE_SYNC | WRITE_FLUSH_FUA, bh);
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else
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ret = submit_bh(WRITE_SYNC, bh);
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*cbh = bh;
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return ret;
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}
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/*
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* This function along with journal_submit_commit_record
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* allows to write the commit record asynchronously.
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*/
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static int journal_wait_on_commit_record(journal_t *journal,
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struct buffer_head *bh)
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{
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int ret = 0;
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clear_buffer_dirty(bh);
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wait_on_buffer(bh);
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if (unlikely(!buffer_uptodate(bh)))
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ret = -EIO;
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put_bh(bh); /* One for getblk() */
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jbd2_journal_put_journal_head(bh2jh(bh));
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return ret;
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}
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/*
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* write the filemap data using writepage() address_space_operations.
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* We don't do block allocation here even for delalloc. We don't
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* use writepages() because with dealyed allocation we may be doing
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* block allocation in writepages().
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*/
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static int journal_submit_inode_data_buffers(struct address_space *mapping)
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{
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int ret;
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struct writeback_control wbc = {
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.sync_mode = WB_SYNC_ALL,
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.nr_to_write = mapping->nrpages * 2,
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.range_start = 0,
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.range_end = i_size_read(mapping->host),
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};
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ret = generic_writepages(mapping, &wbc);
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return ret;
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}
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/*
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* Submit all the data buffers of inode associated with the transaction to
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* disk.
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*
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* We are in a committing transaction. Therefore no new inode can be added to
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* our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
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* operate on from being released while we write out pages.
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*/
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static int journal_submit_data_buffers(journal_t *journal,
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transaction_t *commit_transaction)
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{
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struct jbd2_inode *jinode;
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int err, ret = 0;
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struct address_space *mapping;
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spin_lock(&journal->j_list_lock);
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list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
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mapping = jinode->i_vfs_inode->i_mapping;
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set_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
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spin_unlock(&journal->j_list_lock);
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/*
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* submit the inode data buffers. We use writepage
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* instead of writepages. Because writepages can do
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* block allocation with delalloc. We need to write
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* only allocated blocks here.
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*/
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trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
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err = journal_submit_inode_data_buffers(mapping);
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if (!ret)
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ret = err;
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spin_lock(&journal->j_list_lock);
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J_ASSERT(jinode->i_transaction == commit_transaction);
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commit_transaction->t_flushed_data_blocks = 1;
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clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
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smp_mb__after_clear_bit();
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wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
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}
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spin_unlock(&journal->j_list_lock);
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return ret;
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}
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/*
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* Wait for data submitted for writeout, refile inodes to proper
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* transaction if needed.
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*
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*/
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static int journal_finish_inode_data_buffers(journal_t *journal,
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transaction_t *commit_transaction)
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{
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struct jbd2_inode *jinode, *next_i;
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int err, ret = 0;
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/* For locking, see the comment in journal_submit_data_buffers() */
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spin_lock(&journal->j_list_lock);
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list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
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set_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
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spin_unlock(&journal->j_list_lock);
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err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
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if (err) {
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/*
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* Because AS_EIO is cleared by
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* filemap_fdatawait_range(), set it again so
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* that user process can get -EIO from fsync().
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*/
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set_bit(AS_EIO,
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&jinode->i_vfs_inode->i_mapping->flags);
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if (!ret)
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ret = err;
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}
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spin_lock(&journal->j_list_lock);
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clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
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smp_mb__after_clear_bit();
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wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
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}
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/* Now refile inode to proper lists */
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list_for_each_entry_safe(jinode, next_i,
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&commit_transaction->t_inode_list, i_list) {
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list_del(&jinode->i_list);
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if (jinode->i_next_transaction) {
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jinode->i_transaction = jinode->i_next_transaction;
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jinode->i_next_transaction = NULL;
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list_add(&jinode->i_list,
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&jinode->i_transaction->t_inode_list);
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} else {
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jinode->i_transaction = NULL;
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}
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}
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spin_unlock(&journal->j_list_lock);
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return ret;
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}
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static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
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{
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struct page *page = bh->b_page;
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char *addr;
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__u32 checksum;
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addr = kmap_atomic(page, KM_USER0);
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checksum = crc32_be(crc32_sum,
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(void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
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kunmap_atomic(addr, KM_USER0);
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return checksum;
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}
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static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
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unsigned long long block)
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{
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tag->t_blocknr = cpu_to_be32(block & (u32)~0);
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if (tag_bytes > JBD2_TAG_SIZE32)
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tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
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}
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/*
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* jbd2_journal_commit_transaction
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*
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* The primary function for committing a transaction to the log. This
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* function is called by the journal thread to begin a complete commit.
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*/
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void jbd2_journal_commit_transaction(journal_t *journal)
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{
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struct transaction_stats_s stats;
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transaction_t *commit_transaction;
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struct journal_head *jh, *new_jh, *descriptor;
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struct buffer_head **wbuf = journal->j_wbuf;
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int bufs;
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int flags;
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int err;
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unsigned long long blocknr;
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ktime_t start_time;
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u64 commit_time;
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char *tagp = NULL;
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journal_header_t *header;
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journal_block_tag_t *tag = NULL;
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int space_left = 0;
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int first_tag = 0;
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int tag_flag;
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int i, to_free = 0;
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int tag_bytes = journal_tag_bytes(journal);
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struct buffer_head *cbh = NULL; /* For transactional checksums */
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__u32 crc32_sum = ~0;
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struct blk_plug plug;
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/*
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* First job: lock down the current transaction and wait for
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* all outstanding updates to complete.
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*/
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#ifdef COMMIT_STATS
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spin_lock(&journal->j_list_lock);
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summarise_journal_usage(journal);
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spin_unlock(&journal->j_list_lock);
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#endif
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/* Do we need to erase the effects of a prior jbd2_journal_flush? */
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if (journal->j_flags & JBD2_FLUSHED) {
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jbd_debug(3, "super block updated\n");
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jbd2_journal_update_superblock(journal, 1);
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} else {
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jbd_debug(3, "superblock not updated\n");
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}
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J_ASSERT(journal->j_running_transaction != NULL);
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J_ASSERT(journal->j_committing_transaction == NULL);
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commit_transaction = journal->j_running_transaction;
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J_ASSERT(commit_transaction->t_state == T_RUNNING);
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trace_jbd2_start_commit(journal, commit_transaction);
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jbd_debug(1, "JBD: starting commit of transaction %d\n",
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commit_transaction->t_tid);
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write_lock(&journal->j_state_lock);
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commit_transaction->t_state = T_LOCKED;
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trace_jbd2_commit_locking(journal, commit_transaction);
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stats.run.rs_wait = commit_transaction->t_max_wait;
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stats.run.rs_locked = jiffies;
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stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
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stats.run.rs_locked);
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spin_lock(&commit_transaction->t_handle_lock);
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while (atomic_read(&commit_transaction->t_updates)) {
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DEFINE_WAIT(wait);
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prepare_to_wait(&journal->j_wait_updates, &wait,
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TASK_UNINTERRUPTIBLE);
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if (atomic_read(&commit_transaction->t_updates)) {
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spin_unlock(&commit_transaction->t_handle_lock);
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write_unlock(&journal->j_state_lock);
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schedule();
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write_lock(&journal->j_state_lock);
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spin_lock(&commit_transaction->t_handle_lock);
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}
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finish_wait(&journal->j_wait_updates, &wait);
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}
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spin_unlock(&commit_transaction->t_handle_lock);
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J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
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journal->j_max_transaction_buffers);
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/*
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* First thing we are allowed to do is to discard any remaining
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* BJ_Reserved buffers. Note, it is _not_ permissible to assume
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* that there are no such buffers: if a large filesystem
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* operation like a truncate needs to split itself over multiple
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* transactions, then it may try to do a jbd2_journal_restart() while
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* there are still BJ_Reserved buffers outstanding. These must
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* be released cleanly from the current transaction.
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*
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* In this case, the filesystem must still reserve write access
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* again before modifying the buffer in the new transaction, but
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* we do not require it to remember exactly which old buffers it
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* has reserved. This is consistent with the existing behaviour
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* that multiple jbd2_journal_get_write_access() calls to the same
|
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* buffer are perfectly permissable.
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*/
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while (commit_transaction->t_reserved_list) {
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jh = commit_transaction->t_reserved_list;
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JBUFFER_TRACE(jh, "reserved, unused: refile");
|
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/*
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* A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
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* leave undo-committed data.
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*/
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if (jh->b_committed_data) {
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struct buffer_head *bh = jh2bh(jh);
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|
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jbd_lock_bh_state(bh);
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jbd2_free(jh->b_committed_data, bh->b_size);
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jh->b_committed_data = NULL;
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jbd_unlock_bh_state(bh);
|
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}
|
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jbd2_journal_refile_buffer(journal, jh);
|
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}
|
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|
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/*
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* Now try to drop any written-back buffers from the journal's
|
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* checkpoint lists. We do this *before* commit because it potentially
|
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* frees some memory
|
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*/
|
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spin_lock(&journal->j_list_lock);
|
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__jbd2_journal_clean_checkpoint_list(journal);
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spin_unlock(&journal->j_list_lock);
|
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|
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jbd_debug (3, "JBD: commit phase 1\n");
|
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|
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/*
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* Switch to a new revoke table.
|
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*/
|
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jbd2_journal_switch_revoke_table(journal);
|
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|
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trace_jbd2_commit_flushing(journal, commit_transaction);
|
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stats.run.rs_flushing = jiffies;
|
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stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
|
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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;
|
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wake_up(&journal->j_wait_transaction_locked);
|
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write_unlock(&journal->j_state_lock);
|
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|
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jbd_debug (3, "JBD: commit phase 2\n");
|
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|
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/*
|
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* Now start flushing things to disk, in the order they appear
|
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* on the transaction lists. Data blocks go first.
|
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*/
|
|
err = journal_submit_data_buffers(journal, commit_transaction);
|
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if (err)
|
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jbd2_journal_abort(journal, err);
|
|
|
|
blk_start_plug(&plug);
|
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jbd2_journal_write_revoke_records(journal, commit_transaction,
|
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WRITE_SYNC);
|
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blk_finish_plug(&plug);
|
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|
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jbd_debug(3, "JBD: commit phase 2\n");
|
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|
|
/*
|
|
* Way to go: we have now written out all of the data for a
|
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* transaction! Now comes the tricky part: we need to write out
|
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* metadata. Loop over the transaction's entire buffer list:
|
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*/
|
|
write_lock(&journal->j_state_lock);
|
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commit_transaction->t_state = T_COMMIT;
|
|
write_unlock(&journal->j_state_lock);
|
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|
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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 =
|
|
atomic_read(&commit_transaction->t_outstanding_credits);
|
|
stats.run.rs_blocks_logged = 0;
|
|
|
|
J_ASSERT(commit_transaction->t_nr_buffers <=
|
|
atomic_read(&commit_transaction->t_outstanding_credits));
|
|
|
|
err = 0;
|
|
descriptor = NULL;
|
|
bufs = 0;
|
|
blk_start_plug(&plug);
|
|
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) {
|
|
struct buffer_head *bh;
|
|
|
|
J_ASSERT (bufs == 0);
|
|
|
|
jbd_debug(4, "JBD: get descriptor\n");
|
|
|
|
descriptor = jbd2_journal_get_descriptor_buffer(journal);
|
|
if (!descriptor) {
|
|
jbd2_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(JBD2_MAGIC_NUMBER);
|
|
header->h_blocktype = cpu_to_be32(JBD2_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");
|
|
jbd2_journal_file_buffer(descriptor, commit_transaction,
|
|
BJ_LogCtl);
|
|
}
|
|
|
|
/* 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, but this counter is changed
|
|
* by jbd2_journal_next_log_block() also.
|
|
*/
|
|
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 BJ_IO/BJ_Shadow pairing of buffers. */
|
|
atomic_inc(&jh2bh(jh)->b_count);
|
|
|
|
/* 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_bit(BH_JWrite, &jh2bh(jh)->b_state);
|
|
/*
|
|
* akpm: jbd2_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 = jbd2_journal_write_metadata_buffer(commit_transaction,
|
|
jh, &new_jh, blocknr);
|
|
if (flags < 0) {
|
|
jbd2_journal_abort(journal, flags);
|
|
continue;
|
|
}
|
|
set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
|
|
wbuf[bufs++] = jh2bh(new_jh);
|
|
|
|
/* 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(tag_bytes, tag, jh2bh(jh)->b_blocknr);
|
|
tag->t_flags = cpu_to_be32(tag_flag);
|
|
tagp += tag_bytes;
|
|
space_left -= tag_bytes;
|
|
|
|
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) {
|
|
|
|
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(JBD2_FLAG_LAST_TAG);
|
|
|
|
start_journal_io:
|
|
for (i = 0; i < bufs; i++) {
|
|
struct buffer_head *bh = wbuf[i];
|
|
/*
|
|
* Compute checksum.
|
|
*/
|
|
if (JBD2_HAS_COMPAT_FEATURE(journal,
|
|
JBD2_FEATURE_COMPAT_CHECKSUM)) {
|
|
crc32_sum =
|
|
jbd2_checksum_data(crc32_sum, bh);
|
|
}
|
|
|
|
lock_buffer(bh);
|
|
clear_buffer_dirty(bh);
|
|
set_buffer_uptodate(bh);
|
|
bh->b_end_io = journal_end_buffer_io_sync;
|
|
submit_bh(WRITE_SYNC, bh);
|
|
}
|
|
cond_resched();
|
|
stats.run.rs_blocks_logged += bufs;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/*
|
|
* 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_flushed_data_blocks &&
|
|
(journal->j_fs_dev != journal->j_dev) &&
|
|
(journal->j_flags & JBD2_BARRIER))
|
|
blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
|
|
|
|
/* Done it all: now write the commit record asynchronously. */
|
|
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
|
|
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
|
|
err = journal_submit_commit_record(journal, commit_transaction,
|
|
&cbh, crc32_sum);
|
|
if (err)
|
|
__jbd2_journal_abort_hard(journal);
|
|
}
|
|
|
|
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 3\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");
|
|
jbd2_journal_unfile_buffer(journal, jh);
|
|
|
|
/*
|
|
* ->t_iobuf_list should contain only dummy buffer_heads
|
|
* which were created by jbd2_journal_write_metadata_buffer().
|
|
*/
|
|
BUFFER_TRACE(bh, "dumping temporary bh");
|
|
jbd2_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_bit(BH_JWrite, &bh->b_state);
|
|
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");
|
|
jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
|
|
/* Wake up any transactions which were waiting for this
|
|
IO to complete */
|
|
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 4\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);
|
|
jbd2_journal_unfile_buffer(journal, jh);
|
|
jbd2_journal_put_journal_head(jh);
|
|
__brelse(bh); /* One for getblk */
|
|
/* AKPM: bforget here */
|
|
}
|
|
|
|
if (err)
|
|
jbd2_journal_abort(journal, err);
|
|
|
|
jbd_debug(3, "JBD: commit phase 5\n");
|
|
|
|
if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
|
|
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
|
|
err = journal_submit_commit_record(journal, commit_transaction,
|
|
&cbh, crc32_sum);
|
|
if (err)
|
|
__jbd2_journal_abort_hard(journal);
|
|
}
|
|
if (!err && !is_journal_aborted(journal))
|
|
err = journal_wait_on_commit_record(journal, cbh);
|
|
if (JBD2_HAS_INCOMPAT_FEATURE(journal,
|
|
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
|
|
journal->j_flags & JBD2_BARRIER) {
|
|
blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL);
|
|
}
|
|
|
|
if (err)
|
|
jbd2_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 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_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;
|
|
|
|
jh = commit_transaction->t_forget;
|
|
spin_unlock(&journal->j_list_lock);
|
|
bh = jh2bh(jh);
|
|
jbd_lock_bh_state(bh);
|
|
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 may end up still
|
|
* being dirty here, but we want to avoid writing back
|
|
* that buffer in the future after the "add to orphan"
|
|
* operation been committed, That's not only a performance
|
|
* gain, it also stops aliasing problems if the buffer is
|
|
* left behind for writeback and gets reallocated for another
|
|
* use in a different page. */
|
|
if (buffer_freed(bh) && !jh->b_next_transaction) {
|
|
clear_buffer_freed(bh);
|
|
clear_buffer_jbddirty(bh);
|
|
}
|
|
|
|
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);
|
|
JBUFFER_TRACE(jh, "refile for checkpoint writeback");
|
|
__jbd2_journal_refile_buffer(jh);
|
|
jbd_unlock_bh_state(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. */
|
|
JBUFFER_TRACE(jh, "refile or unfile freed buffer");
|
|
__jbd2_journal_refile_buffer(jh);
|
|
if (!jh->b_transaction) {
|
|
jbd_unlock_bh_state(bh);
|
|
/* needs a brelse */
|
|
jbd2_journal_remove_journal_head(bh);
|
|
release_buffer_page(bh);
|
|
} else
|
|
jbd_unlock_bh_state(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;
|
|
}
|
|
|
|
/* Done with this transaction! */
|
|
|
|
jbd_debug(3, "JBD: commit phase 7\n");
|
|
|
|
J_ASSERT(commit_transaction->t_state == T_COMMIT);
|
|
|
|
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);
|
|
|
|
/*
|
|
* Calculate overall stats
|
|
*/
|
|
spin_lock(&journal->j_history_lock);
|
|
journal->j_stats.ts_tid++;
|
|
journal->j_stats.run.rs_wait += stats.run.rs_wait;
|
|
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);
|
|
|
|
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 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 (commit_transaction->t_checkpoint_list == NULL &&
|
|
commit_transaction->t_checkpoint_io_list == NULL) {
|
|
__jbd2_journal_drop_transaction(journal, commit_transaction);
|
|
to_free = 1;
|
|
} 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);
|
|
|
|
if (journal->j_commit_callback)
|
|
journal->j_commit_callback(journal, commit_transaction);
|
|
|
|
trace_jbd2_end_commit(journal, commit_transaction);
|
|
jbd_debug(1, "JBD: commit %d complete, head %d\n",
|
|
journal->j_commit_sequence, journal->j_tail_sequence);
|
|
if (to_free)
|
|
kfree(commit_transaction);
|
|
|
|
wake_up(&journal->j_wait_done_commit);
|
|
}
|