1022 lines
30 KiB
C
Executable File
1022 lines
30 KiB
C
Executable File
/*
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* linux/fs/jbd/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/jbd.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <trace/events/jbd.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 ext3-ordered file is truncated, it is possible that many pages are
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* not 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 journal->j_list_lock. The caller provided us with a ref
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* 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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* Decrement reference counter for data buffer. If it has been marked
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* 'BH_Freed', release it and the page to which it belongs if possible.
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*/
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static void release_data_buffer(struct buffer_head *bh)
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{
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if (buffer_freed(bh)) {
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WARN_ON_ONCE(buffer_dirty(bh));
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clear_buffer_freed(bh);
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clear_buffer_mapped(bh);
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clear_buffer_new(bh);
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clear_buffer_req(bh);
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bh->b_bdev = NULL;
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release_buffer_page(bh);
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} else
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put_bh(bh);
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}
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/*
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* Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
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* held. For ranking reasons we must trylock. If we lose, schedule away and
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* return 0. j_list_lock is dropped in this case.
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*/
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static int inverted_lock(journal_t *journal, struct buffer_head *bh)
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{
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if (!jbd_trylock_bh_state(bh)) {
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spin_unlock(&journal->j_list_lock);
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schedule();
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return 0;
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}
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return 1;
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}
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/* Done it all: now write 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_write_commit_record(journal_t *journal,
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transaction_t *commit_transaction)
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{
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struct journal_head *descriptor;
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struct buffer_head *bh;
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journal_header_t *header;
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int ret;
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if (is_journal_aborted(journal))
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return 0;
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descriptor = 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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header = (journal_header_t *)(bh->b_data);
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header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
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header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK);
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header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
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JBUFFER_TRACE(descriptor, "write commit block");
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set_buffer_dirty(bh);
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if (journal->j_flags & JFS_BARRIER)
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ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
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else
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ret = sync_dirty_buffer(bh);
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put_bh(bh); /* One for getblk() */
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journal_put_journal_head(descriptor);
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return (ret == -EIO);
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}
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static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
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int write_op)
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{
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int i;
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for (i = 0; i < bufs; i++) {
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wbuf[i]->b_end_io = end_buffer_write_sync;
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/*
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* Here we write back pagecache data that may be mmaped. Since
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* we cannot afford to clean the page and set PageWriteback
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* here due to lock ordering (page lock ranks above transaction
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* start), the data can change while IO is in flight. Tell the
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* block layer it should bounce the bio pages if stable data
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* during write is required.
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*
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* We use up our safety reference in submit_bh().
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*/
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_submit_bh(write_op, wbuf[i], 1 << BIO_SNAP_STABLE);
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}
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}
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/*
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* Submit all the data buffers to disk
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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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int write_op)
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{
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struct journal_head *jh;
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struct buffer_head *bh;
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int locked;
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int bufs = 0;
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struct buffer_head **wbuf = journal->j_wbuf;
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int err = 0;
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/*
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* Whenever we unlock the journal and sleep, things can get added
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* onto ->t_sync_datalist, so we have to keep looping back to
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* write_out_data until we *know* that the list is empty.
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*
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* Cleanup any flushed data buffers from the data list. Even in
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* abort mode, we want to flush this out as soon as possible.
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*/
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write_out_data:
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cond_resched();
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spin_lock(&journal->j_list_lock);
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while (commit_transaction->t_sync_datalist) {
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jh = commit_transaction->t_sync_datalist;
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bh = jh2bh(jh);
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locked = 0;
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/* Get reference just to make sure buffer does not disappear
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* when we are forced to drop various locks */
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get_bh(bh);
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/* If the buffer is dirty, we need to submit IO and hence
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* we need the buffer lock. We try to lock the buffer without
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* blocking. If we fail, we need to drop j_list_lock and do
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* blocking lock_buffer().
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*/
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if (buffer_dirty(bh)) {
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if (!trylock_buffer(bh)) {
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BUFFER_TRACE(bh, "needs blocking lock");
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spin_unlock(&journal->j_list_lock);
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trace_jbd_do_submit_data(journal,
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commit_transaction);
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/* Write out all data to prevent deadlocks */
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journal_do_submit_data(wbuf, bufs, write_op);
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bufs = 0;
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lock_buffer(bh);
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spin_lock(&journal->j_list_lock);
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}
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locked = 1;
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}
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/* We have to get bh_state lock. Again out of order, sigh. */
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if (!inverted_lock(journal, bh)) {
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jbd_lock_bh_state(bh);
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spin_lock(&journal->j_list_lock);
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}
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/* Someone already cleaned up the buffer? */
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if (!buffer_jbd(bh) || bh2jh(bh) != jh
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|| jh->b_transaction != commit_transaction
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|| jh->b_jlist != BJ_SyncData) {
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jbd_unlock_bh_state(bh);
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if (locked)
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unlock_buffer(bh);
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BUFFER_TRACE(bh, "already cleaned up");
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release_data_buffer(bh);
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continue;
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}
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if (locked && test_clear_buffer_dirty(bh)) {
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BUFFER_TRACE(bh, "needs writeout, adding to array");
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wbuf[bufs++] = bh;
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__journal_file_buffer(jh, commit_transaction,
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BJ_Locked);
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jbd_unlock_bh_state(bh);
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if (bufs == journal->j_wbufsize) {
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spin_unlock(&journal->j_list_lock);
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trace_jbd_do_submit_data(journal,
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commit_transaction);
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journal_do_submit_data(wbuf, bufs, write_op);
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bufs = 0;
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goto write_out_data;
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}
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} else if (!locked && buffer_locked(bh)) {
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__journal_file_buffer(jh, commit_transaction,
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BJ_Locked);
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jbd_unlock_bh_state(bh);
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put_bh(bh);
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} else {
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BUFFER_TRACE(bh, "writeout complete: unfile");
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if (unlikely(!buffer_uptodate(bh)))
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err = -EIO;
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__journal_unfile_buffer(jh);
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jbd_unlock_bh_state(bh);
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if (locked)
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unlock_buffer(bh);
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release_data_buffer(bh);
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}
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if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
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spin_unlock(&journal->j_list_lock);
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goto write_out_data;
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}
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}
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spin_unlock(&journal->j_list_lock);
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trace_jbd_do_submit_data(journal, commit_transaction);
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journal_do_submit_data(wbuf, bufs, write_op);
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return err;
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}
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/*
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* 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 journal_commit_transaction(journal_t *journal)
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{
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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 int 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;
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struct blk_plug plug;
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int write_op = WRITE;
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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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/* Do we need to erase the effects of a prior journal_flush? */
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if (journal->j_flags & JFS_FLUSHED) {
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jbd_debug(3, "super block updated\n");
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mutex_lock(&journal->j_checkpoint_mutex);
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/*
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* We hold j_checkpoint_mutex so tail cannot change under us.
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* We don't need any special data guarantees for writing sb
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* since journal is empty and it is ok for write to be
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* flushed only with transaction commit.
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*/
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journal_update_sb_log_tail(journal, journal->j_tail_sequence,
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journal->j_tail, WRITE_SYNC);
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mutex_unlock(&journal->j_checkpoint_mutex);
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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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trace_jbd_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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spin_lock(&journal->j_state_lock);
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J_ASSERT(commit_transaction->t_state == T_RUNNING);
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commit_transaction->t_state = T_LOCKED;
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trace_jbd_commit_locking(journal, commit_transaction);
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spin_lock(&commit_transaction->t_handle_lock);
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while (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 (commit_transaction->t_updates) {
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spin_unlock(&commit_transaction->t_handle_lock);
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spin_unlock(&journal->j_state_lock);
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schedule();
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spin_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 (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 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 journal_get_write_access() calls to the same
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* buffer are perfectly permissible.
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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 journal_get_undo_access()+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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jbd_lock_bh_state(bh);
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jbd_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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journal_refile_buffer(journal, jh);
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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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__journal_clean_checkpoint_list(journal);
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spin_unlock(&journal->j_list_lock);
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jbd_debug (3, "JBD: commit phase 1\n");
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/*
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* Clear revoked flag to reflect there is no revoked buffers
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* in the next transaction which is going to be started.
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*/
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journal_clear_buffer_revoked_flags(journal);
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/*
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* Switch to a new revoke table.
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*/
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journal_switch_revoke_table(journal);
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trace_jbd_commit_flushing(journal, commit_transaction);
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commit_transaction->t_state = T_FLUSH;
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journal->j_committing_transaction = commit_transaction;
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journal->j_running_transaction = NULL;
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start_time = ktime_get();
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commit_transaction->t_log_start = journal->j_head;
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wake_up(&journal->j_wait_transaction_locked);
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spin_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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if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid))
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write_op = WRITE_SYNC;
|
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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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*/
|
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blk_start_plug(&plug);
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err = journal_submit_data_buffers(journal, commit_transaction,
|
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write_op);
|
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blk_finish_plug(&plug);
|
|
|
|
/*
|
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* Wait for all previously submitted IO to complete.
|
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*/
|
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spin_lock(&journal->j_list_lock);
|
|
while (commit_transaction->t_locked_list) {
|
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struct buffer_head *bh;
|
|
|
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jh = commit_transaction->t_locked_list->b_tprev;
|
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bh = jh2bh(jh);
|
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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)) {
|
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spin_unlock(&journal->j_list_lock);
|
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lock_page(bh->b_page);
|
|
spin_lock(&journal->j_list_lock);
|
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}
|
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if (bh->b_page->mapping)
|
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set_bit(AS_EIO, &bh->b_page->mapping->flags);
|
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|
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unlock_page(bh->b_page);
|
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SetPageError(bh->b_page);
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err = -EIO;
|
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}
|
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if (!inverted_lock(journal, bh)) {
|
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put_bh(bh);
|
|
spin_lock(&journal->j_list_lock);
|
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continue;
|
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}
|
|
if (buffer_jbd(bh) && bh2jh(bh) == jh &&
|
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jh->b_transaction == commit_transaction &&
|
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jh->b_jlist == BJ_Locked)
|
|
__journal_unfile_buffer(jh);
|
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jbd_unlock_bh_state(bh);
|
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release_data_buffer(bh);
|
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cond_resched_lock(&journal->j_list_lock);
|
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}
|
|
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)
|
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journal_abort(journal, err);
|
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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);
|
|
}
|