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If the thread failed to create the subsequent wait_event will hang forever. This is likely to happen if kernel hits max_threads limit. Will be critical for virtualization systems that limit the number of tasks and kernel memory usage within the container. (akpm: JBD should be converted fully to the kthread API: kthread_should_stop() and kthread_stop()). Cc: <linux-ext4@vger.kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2089 lines
56 KiB
C
2089 lines
56 KiB
C
/*
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* linux/fs/jbd2/journal.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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* Generic filesystem journal-writing code; part of the ext2fs
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* journaling system.
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*
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* This file manages journals: areas of disk reserved for logging
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* transactional updates. This includes the kernel journaling thread
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* which is responsible for scheduling updates to the log.
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*
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* We do not actually manage the physical storage of the journal in this
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* file: that is left to a per-journal policy function, which allows us
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* to store the journal within a filesystem-specified area for ext2
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* journaling (ext2 can use a reserved inode for storing the log).
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*/
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#include <linux/module.h>
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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/init.h>
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#include <linux/mm.h>
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#include <linux/freezer.h>
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#include <linux/pagemap.h>
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#include <linux/kthread.h>
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#include <linux/poison.h>
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#include <linux/proc_fs.h>
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#include <asm/uaccess.h>
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#include <asm/page.h>
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EXPORT_SYMBOL(jbd2_journal_start);
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EXPORT_SYMBOL(jbd2_journal_restart);
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EXPORT_SYMBOL(jbd2_journal_extend);
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EXPORT_SYMBOL(jbd2_journal_stop);
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EXPORT_SYMBOL(jbd2_journal_lock_updates);
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EXPORT_SYMBOL(jbd2_journal_unlock_updates);
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EXPORT_SYMBOL(jbd2_journal_get_write_access);
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EXPORT_SYMBOL(jbd2_journal_get_create_access);
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EXPORT_SYMBOL(jbd2_journal_get_undo_access);
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EXPORT_SYMBOL(jbd2_journal_dirty_data);
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EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
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EXPORT_SYMBOL(jbd2_journal_release_buffer);
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EXPORT_SYMBOL(jbd2_journal_forget);
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#if 0
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EXPORT_SYMBOL(journal_sync_buffer);
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#endif
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EXPORT_SYMBOL(jbd2_journal_flush);
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EXPORT_SYMBOL(jbd2_journal_revoke);
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EXPORT_SYMBOL(jbd2_journal_init_dev);
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EXPORT_SYMBOL(jbd2_journal_init_inode);
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EXPORT_SYMBOL(jbd2_journal_update_format);
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EXPORT_SYMBOL(jbd2_journal_check_used_features);
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EXPORT_SYMBOL(jbd2_journal_check_available_features);
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EXPORT_SYMBOL(jbd2_journal_set_features);
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EXPORT_SYMBOL(jbd2_journal_create);
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EXPORT_SYMBOL(jbd2_journal_load);
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EXPORT_SYMBOL(jbd2_journal_destroy);
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EXPORT_SYMBOL(jbd2_journal_update_superblock);
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EXPORT_SYMBOL(jbd2_journal_abort);
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EXPORT_SYMBOL(jbd2_journal_errno);
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EXPORT_SYMBOL(jbd2_journal_ack_err);
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EXPORT_SYMBOL(jbd2_journal_clear_err);
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EXPORT_SYMBOL(jbd2_log_wait_commit);
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EXPORT_SYMBOL(jbd2_journal_start_commit);
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EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
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EXPORT_SYMBOL(jbd2_journal_wipe);
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EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
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EXPORT_SYMBOL(jbd2_journal_invalidatepage);
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EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
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EXPORT_SYMBOL(jbd2_journal_force_commit);
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static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
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static void __journal_abort_soft (journal_t *journal, int errno);
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static int jbd2_journal_create_jbd_slab(size_t slab_size);
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/*
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* Helper function used to manage commit timeouts
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*/
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static void commit_timeout(unsigned long __data)
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{
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struct task_struct * p = (struct task_struct *) __data;
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wake_up_process(p);
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}
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/*
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* kjournald2: The main thread function used to manage a logging device
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* journal.
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*
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* This kernel thread is responsible for two things:
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*
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* 1) COMMIT: Every so often we need to commit the current state of the
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* filesystem to disk. The journal thread is responsible for writing
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* all of the metadata buffers to disk.
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*
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* 2) CHECKPOINT: We cannot reuse a used section of the log file until all
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* of the data in that part of the log has been rewritten elsewhere on
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* the disk. Flushing these old buffers to reclaim space in the log is
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* known as checkpointing, and this thread is responsible for that job.
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*/
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static int kjournald2(void *arg)
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{
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journal_t *journal = arg;
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transaction_t *transaction;
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/*
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* Set up an interval timer which can be used to trigger a commit wakeup
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* after the commit interval expires
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*/
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setup_timer(&journal->j_commit_timer, commit_timeout,
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(unsigned long)current);
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/* Record that the journal thread is running */
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journal->j_task = current;
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wake_up(&journal->j_wait_done_commit);
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printk(KERN_INFO "kjournald2 starting. Commit interval %ld seconds\n",
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journal->j_commit_interval / HZ);
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/*
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* And now, wait forever for commit wakeup events.
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*/
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spin_lock(&journal->j_state_lock);
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loop:
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if (journal->j_flags & JBD2_UNMOUNT)
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goto end_loop;
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jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
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journal->j_commit_sequence, journal->j_commit_request);
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if (journal->j_commit_sequence != journal->j_commit_request) {
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jbd_debug(1, "OK, requests differ\n");
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spin_unlock(&journal->j_state_lock);
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del_timer_sync(&journal->j_commit_timer);
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jbd2_journal_commit_transaction(journal);
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spin_lock(&journal->j_state_lock);
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goto loop;
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}
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wake_up(&journal->j_wait_done_commit);
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if (freezing(current)) {
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/*
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* The simpler the better. Flushing journal isn't a
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* good idea, because that depends on threads that may
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* be already stopped.
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*/
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jbd_debug(1, "Now suspending kjournald2\n");
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spin_unlock(&journal->j_state_lock);
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refrigerator();
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spin_lock(&journal->j_state_lock);
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} else {
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/*
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* We assume on resume that commits are already there,
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* so we don't sleep
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*/
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DEFINE_WAIT(wait);
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int should_sleep = 1;
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prepare_to_wait(&journal->j_wait_commit, &wait,
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TASK_INTERRUPTIBLE);
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if (journal->j_commit_sequence != journal->j_commit_request)
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should_sleep = 0;
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transaction = journal->j_running_transaction;
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if (transaction && time_after_eq(jiffies,
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transaction->t_expires))
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should_sleep = 0;
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if (journal->j_flags & JBD2_UNMOUNT)
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should_sleep = 0;
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if (should_sleep) {
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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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}
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finish_wait(&journal->j_wait_commit, &wait);
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}
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jbd_debug(1, "kjournald2 wakes\n");
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/*
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* Were we woken up by a commit wakeup event?
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*/
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transaction = journal->j_running_transaction;
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if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
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journal->j_commit_request = transaction->t_tid;
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jbd_debug(1, "woke because of timeout\n");
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}
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goto loop;
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end_loop:
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spin_unlock(&journal->j_state_lock);
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del_timer_sync(&journal->j_commit_timer);
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journal->j_task = NULL;
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wake_up(&journal->j_wait_done_commit);
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jbd_debug(1, "Journal thread exiting.\n");
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return 0;
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}
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static int jbd2_journal_start_thread(journal_t *journal)
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{
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struct task_struct *t;
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t = kthread_run(kjournald2, journal, "kjournald2");
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if (IS_ERR(t))
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return PTR_ERR(t);
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wait_event(journal->j_wait_done_commit, journal->j_task != 0);
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return 0;
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}
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static void journal_kill_thread(journal_t *journal)
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{
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spin_lock(&journal->j_state_lock);
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journal->j_flags |= JBD2_UNMOUNT;
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while (journal->j_task) {
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wake_up(&journal->j_wait_commit);
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spin_unlock(&journal->j_state_lock);
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wait_event(journal->j_wait_done_commit, journal->j_task == 0);
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spin_lock(&journal->j_state_lock);
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}
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spin_unlock(&journal->j_state_lock);
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}
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/*
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* jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
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*
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* Writes a metadata buffer to a given disk block. The actual IO is not
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* performed but a new buffer_head is constructed which labels the data
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* to be written with the correct destination disk block.
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*
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* Any magic-number escaping which needs to be done will cause a
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* copy-out here. If the buffer happens to start with the
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* JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
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* magic number is only written to the log for descripter blocks. In
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* this case, we copy the data and replace the first word with 0, and we
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* return a result code which indicates that this buffer needs to be
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* marked as an escaped buffer in the corresponding log descriptor
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* block. The missing word can then be restored when the block is read
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* during recovery.
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*
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* If the source buffer has already been modified by a new transaction
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* since we took the last commit snapshot, we use the frozen copy of
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* that data for IO. If we end up using the existing buffer_head's data
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* for the write, then we *have* to lock the buffer to prevent anyone
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* else from using and possibly modifying it while the IO is in
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* progress.
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*
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* The function returns a pointer to the buffer_heads to be used for IO.
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*
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* We assume that the journal has already been locked in this function.
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*
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* Return value:
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* <0: Error
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* >=0: Finished OK
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*
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* On success:
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* Bit 0 set == escape performed on the data
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* Bit 1 set == buffer copy-out performed (kfree the data after IO)
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*/
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int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
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struct journal_head *jh_in,
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struct journal_head **jh_out,
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unsigned long long blocknr)
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{
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int need_copy_out = 0;
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int done_copy_out = 0;
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int do_escape = 0;
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char *mapped_data;
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struct buffer_head *new_bh;
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struct journal_head *new_jh;
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struct page *new_page;
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unsigned int new_offset;
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struct buffer_head *bh_in = jh2bh(jh_in);
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/*
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* The buffer really shouldn't be locked: only the current committing
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* transaction is allowed to write it, so nobody else is allowed
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* to do any IO.
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*
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* akpm: except if we're journalling data, and write() output is
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* also part of a shared mapping, and another thread has
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* decided to launch a writepage() against this buffer.
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*/
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J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
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new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
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/*
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* If a new transaction has already done a buffer copy-out, then
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* we use that version of the data for the commit.
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*/
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jbd_lock_bh_state(bh_in);
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repeat:
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if (jh_in->b_frozen_data) {
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done_copy_out = 1;
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new_page = virt_to_page(jh_in->b_frozen_data);
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new_offset = offset_in_page(jh_in->b_frozen_data);
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} else {
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new_page = jh2bh(jh_in)->b_page;
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new_offset = offset_in_page(jh2bh(jh_in)->b_data);
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}
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mapped_data = kmap_atomic(new_page, KM_USER0);
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/*
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* Check for escaping
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*/
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if (*((__be32 *)(mapped_data + new_offset)) ==
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cpu_to_be32(JBD2_MAGIC_NUMBER)) {
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need_copy_out = 1;
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do_escape = 1;
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}
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kunmap_atomic(mapped_data, KM_USER0);
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/*
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* Do we need to do a data copy?
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*/
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if (need_copy_out && !done_copy_out) {
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char *tmp;
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jbd_unlock_bh_state(bh_in);
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tmp = jbd2_slab_alloc(bh_in->b_size, GFP_NOFS);
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jbd_lock_bh_state(bh_in);
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if (jh_in->b_frozen_data) {
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jbd2_slab_free(tmp, bh_in->b_size);
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goto repeat;
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}
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jh_in->b_frozen_data = tmp;
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mapped_data = kmap_atomic(new_page, KM_USER0);
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memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
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kunmap_atomic(mapped_data, KM_USER0);
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new_page = virt_to_page(tmp);
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new_offset = offset_in_page(tmp);
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done_copy_out = 1;
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}
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/*
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* Did we need to do an escaping? Now we've done all the
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* copying, we can finally do so.
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*/
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if (do_escape) {
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mapped_data = kmap_atomic(new_page, KM_USER0);
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*((unsigned int *)(mapped_data + new_offset)) = 0;
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kunmap_atomic(mapped_data, KM_USER0);
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}
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/* keep subsequent assertions sane */
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new_bh->b_state = 0;
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init_buffer(new_bh, NULL, NULL);
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atomic_set(&new_bh->b_count, 1);
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jbd_unlock_bh_state(bh_in);
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new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
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set_bh_page(new_bh, new_page, new_offset);
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new_jh->b_transaction = NULL;
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new_bh->b_size = jh2bh(jh_in)->b_size;
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new_bh->b_bdev = transaction->t_journal->j_dev;
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new_bh->b_blocknr = blocknr;
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set_buffer_mapped(new_bh);
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set_buffer_dirty(new_bh);
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*jh_out = new_jh;
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/*
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* The to-be-written buffer needs to get moved to the io queue,
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* and the original buffer whose contents we are shadowing or
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* copying is moved to the transaction's shadow queue.
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*/
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JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
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jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
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JBUFFER_TRACE(new_jh, "file as BJ_IO");
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jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
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return do_escape | (done_copy_out << 1);
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}
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/*
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* Allocation code for the journal file. Manage the space left in the
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* journal, so that we can begin checkpointing when appropriate.
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*/
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/*
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* __jbd2_log_space_left: Return the number of free blocks left in the journal.
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*
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* Called with the journal already locked.
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*
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* Called under j_state_lock
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*/
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int __jbd2_log_space_left(journal_t *journal)
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{
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int left = journal->j_free;
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assert_spin_locked(&journal->j_state_lock);
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|
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/*
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* Be pessimistic here about the number of those free blocks which
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* might be required for log descriptor control blocks.
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*/
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#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
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left -= MIN_LOG_RESERVED_BLOCKS;
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if (left <= 0)
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return 0;
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left -= (left >> 3);
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return left;
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}
|
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|
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/*
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* Called under j_state_lock. Returns true if a transaction was started.
|
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*/
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int __jbd2_log_start_commit(journal_t *journal, tid_t target)
|
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{
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/*
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* Are we already doing a recent enough commit?
|
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*/
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if (!tid_geq(journal->j_commit_request, target)) {
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/*
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* We want a new commit: OK, mark the request and wakup the
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* commit thread. We do _not_ do the commit ourselves.
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*/
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journal->j_commit_request = target;
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jbd_debug(1, "JBD: requesting commit %d/%d\n",
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journal->j_commit_request,
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journal->j_commit_sequence);
|
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wake_up(&journal->j_wait_commit);
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return 1;
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}
|
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return 0;
|
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}
|
|
|
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int jbd2_log_start_commit(journal_t *journal, tid_t tid)
|
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{
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int ret;
|
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|
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spin_lock(&journal->j_state_lock);
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ret = __jbd2_log_start_commit(journal, tid);
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spin_unlock(&journal->j_state_lock);
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return ret;
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}
|
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|
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/*
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* Force and wait upon a commit if the calling process is not within
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* transaction. This is used for forcing out undo-protected data which contains
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* bitmaps, when the fs is running out of space.
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*
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* We can only force the running transaction if we don't have an active handle;
|
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* otherwise, we will deadlock.
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*
|
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* Returns true if a transaction was started.
|
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*/
|
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int jbd2_journal_force_commit_nested(journal_t *journal)
|
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{
|
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transaction_t *transaction = NULL;
|
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tid_t tid;
|
|
|
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spin_lock(&journal->j_state_lock);
|
|
if (journal->j_running_transaction && !current->journal_info) {
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transaction = journal->j_running_transaction;
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__jbd2_log_start_commit(journal, transaction->t_tid);
|
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} else if (journal->j_committing_transaction)
|
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transaction = journal->j_committing_transaction;
|
|
|
|
if (!transaction) {
|
|
spin_unlock(&journal->j_state_lock);
|
|
return 0; /* Nothing to retry */
|
|
}
|
|
|
|
tid = transaction->t_tid;
|
|
spin_unlock(&journal->j_state_lock);
|
|
jbd2_log_wait_commit(journal, tid);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Start a commit of the current running transaction (if any). Returns true
|
|
* if a transaction was started, and fills its tid in at *ptid
|
|
*/
|
|
int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
|
|
{
|
|
int ret = 0;
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
if (journal->j_running_transaction) {
|
|
tid_t tid = journal->j_running_transaction->t_tid;
|
|
|
|
ret = __jbd2_log_start_commit(journal, tid);
|
|
if (ret && ptid)
|
|
*ptid = tid;
|
|
} else if (journal->j_committing_transaction && ptid) {
|
|
/*
|
|
* If ext3_write_super() recently started a commit, then we
|
|
* have to wait for completion of that transaction
|
|
*/
|
|
*ptid = journal->j_committing_transaction->t_tid;
|
|
ret = 1;
|
|
}
|
|
spin_unlock(&journal->j_state_lock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Wait for a specified commit to complete.
|
|
* The caller may not hold the journal lock.
|
|
*/
|
|
int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
|
|
{
|
|
int err = 0;
|
|
|
|
#ifdef CONFIG_JBD_DEBUG
|
|
spin_lock(&journal->j_state_lock);
|
|
if (!tid_geq(journal->j_commit_request, tid)) {
|
|
printk(KERN_EMERG
|
|
"%s: error: j_commit_request=%d, tid=%d\n",
|
|
__FUNCTION__, journal->j_commit_request, tid);
|
|
}
|
|
spin_unlock(&journal->j_state_lock);
|
|
#endif
|
|
spin_lock(&journal->j_state_lock);
|
|
while (tid_gt(tid, journal->j_commit_sequence)) {
|
|
jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
|
|
tid, journal->j_commit_sequence);
|
|
wake_up(&journal->j_wait_commit);
|
|
spin_unlock(&journal->j_state_lock);
|
|
wait_event(journal->j_wait_done_commit,
|
|
!tid_gt(tid, journal->j_commit_sequence));
|
|
spin_lock(&journal->j_state_lock);
|
|
}
|
|
spin_unlock(&journal->j_state_lock);
|
|
|
|
if (unlikely(is_journal_aborted(journal))) {
|
|
printk(KERN_EMERG "journal commit I/O error\n");
|
|
err = -EIO;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Log buffer allocation routines:
|
|
*/
|
|
|
|
int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
|
|
{
|
|
unsigned long blocknr;
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
J_ASSERT(journal->j_free > 1);
|
|
|
|
blocknr = journal->j_head;
|
|
journal->j_head++;
|
|
journal->j_free--;
|
|
if (journal->j_head == journal->j_last)
|
|
journal->j_head = journal->j_first;
|
|
spin_unlock(&journal->j_state_lock);
|
|
return jbd2_journal_bmap(journal, blocknr, retp);
|
|
}
|
|
|
|
/*
|
|
* Conversion of logical to physical block numbers for the journal
|
|
*
|
|
* On external journals the journal blocks are identity-mapped, so
|
|
* this is a no-op. If needed, we can use j_blk_offset - everything is
|
|
* ready.
|
|
*/
|
|
int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
|
|
unsigned long long *retp)
|
|
{
|
|
int err = 0;
|
|
unsigned long long ret;
|
|
|
|
if (journal->j_inode) {
|
|
ret = bmap(journal->j_inode, blocknr);
|
|
if (ret)
|
|
*retp = ret;
|
|
else {
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
printk(KERN_ALERT "%s: journal block not found "
|
|
"at offset %lu on %s\n",
|
|
__FUNCTION__,
|
|
blocknr,
|
|
bdevname(journal->j_dev, b));
|
|
err = -EIO;
|
|
__journal_abort_soft(journal, err);
|
|
}
|
|
} else {
|
|
*retp = blocknr; /* +journal->j_blk_offset */
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* We play buffer_head aliasing tricks to write data/metadata blocks to
|
|
* the journal without copying their contents, but for journal
|
|
* descriptor blocks we do need to generate bona fide buffers.
|
|
*
|
|
* After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
|
|
* the buffer's contents they really should run flush_dcache_page(bh->b_page).
|
|
* But we don't bother doing that, so there will be coherency problems with
|
|
* mmaps of blockdevs which hold live JBD-controlled filesystems.
|
|
*/
|
|
struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
|
|
{
|
|
struct buffer_head *bh;
|
|
unsigned long long blocknr;
|
|
int err;
|
|
|
|
err = jbd2_journal_next_log_block(journal, &blocknr);
|
|
|
|
if (err)
|
|
return NULL;
|
|
|
|
bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
|
|
lock_buffer(bh);
|
|
memset(bh->b_data, 0, journal->j_blocksize);
|
|
set_buffer_uptodate(bh);
|
|
unlock_buffer(bh);
|
|
BUFFER_TRACE(bh, "return this buffer");
|
|
return jbd2_journal_add_journal_head(bh);
|
|
}
|
|
|
|
/*
|
|
* Management for journal control blocks: functions to create and
|
|
* destroy journal_t structures, and to initialise and read existing
|
|
* journal blocks from disk. */
|
|
|
|
/* First: create and setup a journal_t object in memory. We initialise
|
|
* very few fields yet: that has to wait until we have created the
|
|
* journal structures from from scratch, or loaded them from disk. */
|
|
|
|
static journal_t * journal_init_common (void)
|
|
{
|
|
journal_t *journal;
|
|
int err;
|
|
|
|
journal = jbd_kmalloc(sizeof(*journal), GFP_KERNEL);
|
|
if (!journal)
|
|
goto fail;
|
|
memset(journal, 0, sizeof(*journal));
|
|
|
|
init_waitqueue_head(&journal->j_wait_transaction_locked);
|
|
init_waitqueue_head(&journal->j_wait_logspace);
|
|
init_waitqueue_head(&journal->j_wait_done_commit);
|
|
init_waitqueue_head(&journal->j_wait_checkpoint);
|
|
init_waitqueue_head(&journal->j_wait_commit);
|
|
init_waitqueue_head(&journal->j_wait_updates);
|
|
mutex_init(&journal->j_barrier);
|
|
mutex_init(&journal->j_checkpoint_mutex);
|
|
spin_lock_init(&journal->j_revoke_lock);
|
|
spin_lock_init(&journal->j_list_lock);
|
|
spin_lock_init(&journal->j_state_lock);
|
|
|
|
journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE);
|
|
|
|
/* The journal is marked for error until we succeed with recovery! */
|
|
journal->j_flags = JBD2_ABORT;
|
|
|
|
/* Set up a default-sized revoke table for the new mount. */
|
|
err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
|
|
if (err) {
|
|
kfree(journal);
|
|
goto fail;
|
|
}
|
|
return journal;
|
|
fail:
|
|
return NULL;
|
|
}
|
|
|
|
/* jbd2_journal_init_dev and jbd2_journal_init_inode:
|
|
*
|
|
* Create a journal structure assigned some fixed set of disk blocks to
|
|
* the journal. We don't actually touch those disk blocks yet, but we
|
|
* need to set up all of the mapping information to tell the journaling
|
|
* system where the journal blocks are.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure
|
|
* @bdev: Block device on which to create the journal
|
|
* @fs_dev: Device which hold journalled filesystem for this journal.
|
|
* @start: Block nr Start of journal.
|
|
* @len: Length of the journal in blocks.
|
|
* @blocksize: blocksize of journalling device
|
|
* @returns: a newly created journal_t *
|
|
*
|
|
* jbd2_journal_init_dev creates a journal which maps a fixed contiguous
|
|
* range of blocks on an arbitrary block device.
|
|
*
|
|
*/
|
|
journal_t * jbd2_journal_init_dev(struct block_device *bdev,
|
|
struct block_device *fs_dev,
|
|
unsigned long long start, int len, int blocksize)
|
|
{
|
|
journal_t *journal = journal_init_common();
|
|
struct buffer_head *bh;
|
|
int n;
|
|
|
|
if (!journal)
|
|
return NULL;
|
|
|
|
/* journal descriptor can store up to n blocks -bzzz */
|
|
journal->j_blocksize = blocksize;
|
|
n = journal->j_blocksize / sizeof(journal_block_tag_t);
|
|
journal->j_wbufsize = n;
|
|
journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
|
|
if (!journal->j_wbuf) {
|
|
printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
|
|
__FUNCTION__);
|
|
kfree(journal);
|
|
journal = NULL;
|
|
goto out;
|
|
}
|
|
journal->j_dev = bdev;
|
|
journal->j_fs_dev = fs_dev;
|
|
journal->j_blk_offset = start;
|
|
journal->j_maxlen = len;
|
|
|
|
bh = __getblk(journal->j_dev, start, journal->j_blocksize);
|
|
J_ASSERT(bh != NULL);
|
|
journal->j_sb_buffer = bh;
|
|
journal->j_superblock = (journal_superblock_t *)bh->b_data;
|
|
out:
|
|
return journal;
|
|
}
|
|
|
|
/**
|
|
* journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
|
|
* @inode: An inode to create the journal in
|
|
*
|
|
* jbd2_journal_init_inode creates a journal which maps an on-disk inode as
|
|
* the journal. The inode must exist already, must support bmap() and
|
|
* must have all data blocks preallocated.
|
|
*/
|
|
journal_t * jbd2_journal_init_inode (struct inode *inode)
|
|
{
|
|
struct buffer_head *bh;
|
|
journal_t *journal = journal_init_common();
|
|
int err;
|
|
int n;
|
|
unsigned long long blocknr;
|
|
|
|
if (!journal)
|
|
return NULL;
|
|
|
|
journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
|
|
journal->j_inode = inode;
|
|
jbd_debug(1,
|
|
"journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
|
|
journal, inode->i_sb->s_id, inode->i_ino,
|
|
(long long) inode->i_size,
|
|
inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
|
|
|
|
journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
|
|
journal->j_blocksize = inode->i_sb->s_blocksize;
|
|
|
|
/* journal descriptor can store up to n blocks -bzzz */
|
|
n = journal->j_blocksize / sizeof(journal_block_tag_t);
|
|
journal->j_wbufsize = n;
|
|
journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
|
|
if (!journal->j_wbuf) {
|
|
printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
|
|
__FUNCTION__);
|
|
kfree(journal);
|
|
return NULL;
|
|
}
|
|
|
|
err = jbd2_journal_bmap(journal, 0, &blocknr);
|
|
/* If that failed, give up */
|
|
if (err) {
|
|
printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
|
|
__FUNCTION__);
|
|
kfree(journal);
|
|
return NULL;
|
|
}
|
|
|
|
bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
|
|
J_ASSERT(bh != NULL);
|
|
journal->j_sb_buffer = bh;
|
|
journal->j_superblock = (journal_superblock_t *)bh->b_data;
|
|
|
|
return journal;
|
|
}
|
|
|
|
/*
|
|
* If the journal init or create aborts, we need to mark the journal
|
|
* superblock as being NULL to prevent the journal destroy from writing
|
|
* back a bogus superblock.
|
|
*/
|
|
static void journal_fail_superblock (journal_t *journal)
|
|
{
|
|
struct buffer_head *bh = journal->j_sb_buffer;
|
|
brelse(bh);
|
|
journal->j_sb_buffer = NULL;
|
|
}
|
|
|
|
/*
|
|
* Given a journal_t structure, initialise the various fields for
|
|
* startup of a new journaling session. We use this both when creating
|
|
* a journal, and after recovering an old journal to reset it for
|
|
* subsequent use.
|
|
*/
|
|
|
|
static int journal_reset(journal_t *journal)
|
|
{
|
|
journal_superblock_t *sb = journal->j_superblock;
|
|
unsigned long long first, last;
|
|
|
|
first = be32_to_cpu(sb->s_first);
|
|
last = be32_to_cpu(sb->s_maxlen);
|
|
|
|
journal->j_first = first;
|
|
journal->j_last = last;
|
|
|
|
journal->j_head = first;
|
|
journal->j_tail = first;
|
|
journal->j_free = last - first;
|
|
|
|
journal->j_tail_sequence = journal->j_transaction_sequence;
|
|
journal->j_commit_sequence = journal->j_transaction_sequence - 1;
|
|
journal->j_commit_request = journal->j_commit_sequence;
|
|
|
|
journal->j_max_transaction_buffers = journal->j_maxlen / 4;
|
|
|
|
/* Add the dynamic fields and write it to disk. */
|
|
jbd2_journal_update_superblock(journal, 1);
|
|
return jbd2_journal_start_thread(journal);
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_create() - Initialise the new journal file
|
|
* @journal: Journal to create. This structure must have been initialised
|
|
*
|
|
* Given a journal_t structure which tells us which disk blocks we can
|
|
* use, create a new journal superblock and initialise all of the
|
|
* journal fields from scratch.
|
|
**/
|
|
int jbd2_journal_create(journal_t *journal)
|
|
{
|
|
unsigned long long blocknr;
|
|
struct buffer_head *bh;
|
|
journal_superblock_t *sb;
|
|
int i, err;
|
|
|
|
if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) {
|
|
printk (KERN_ERR "Journal length (%d blocks) too short.\n",
|
|
journal->j_maxlen);
|
|
journal_fail_superblock(journal);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (journal->j_inode == NULL) {
|
|
/*
|
|
* We don't know what block to start at!
|
|
*/
|
|
printk(KERN_EMERG
|
|
"%s: creation of journal on external device!\n",
|
|
__FUNCTION__);
|
|
BUG();
|
|
}
|
|
|
|
/* Zero out the entire journal on disk. We cannot afford to
|
|
have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */
|
|
jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
|
|
for (i = 0; i < journal->j_maxlen; i++) {
|
|
err = jbd2_journal_bmap(journal, i, &blocknr);
|
|
if (err)
|
|
return err;
|
|
bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
|
|
lock_buffer(bh);
|
|
memset (bh->b_data, 0, journal->j_blocksize);
|
|
BUFFER_TRACE(bh, "marking dirty");
|
|
mark_buffer_dirty(bh);
|
|
BUFFER_TRACE(bh, "marking uptodate");
|
|
set_buffer_uptodate(bh);
|
|
unlock_buffer(bh);
|
|
__brelse(bh);
|
|
}
|
|
|
|
sync_blockdev(journal->j_dev);
|
|
jbd_debug(1, "JBD: journal cleared.\n");
|
|
|
|
/* OK, fill in the initial static fields in the new superblock */
|
|
sb = journal->j_superblock;
|
|
|
|
sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
|
|
sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
|
|
|
|
sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
|
|
sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
|
|
sb->s_first = cpu_to_be32(1);
|
|
|
|
journal->j_transaction_sequence = 1;
|
|
|
|
journal->j_flags &= ~JBD2_ABORT;
|
|
journal->j_format_version = 2;
|
|
|
|
return journal_reset(journal);
|
|
}
|
|
|
|
/**
|
|
* void jbd2_journal_update_superblock() - Update journal sb on disk.
|
|
* @journal: The journal to update.
|
|
* @wait: Set to '0' if you don't want to wait for IO completion.
|
|
*
|
|
* Update a journal's dynamic superblock fields and write it to disk,
|
|
* optionally waiting for the IO to complete.
|
|
*/
|
|
void jbd2_journal_update_superblock(journal_t *journal, int wait)
|
|
{
|
|
journal_superblock_t *sb = journal->j_superblock;
|
|
struct buffer_head *bh = journal->j_sb_buffer;
|
|
|
|
/*
|
|
* As a special case, if the on-disk copy is already marked as needing
|
|
* no recovery (s_start == 0) and there are no outstanding transactions
|
|
* in the filesystem, then we can safely defer the superblock update
|
|
* until the next commit by setting JBD2_FLUSHED. This avoids
|
|
* attempting a write to a potential-readonly device.
|
|
*/
|
|
if (sb->s_start == 0 && journal->j_tail_sequence ==
|
|
journal->j_transaction_sequence) {
|
|
jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
|
|
"(start %ld, seq %d, errno %d)\n",
|
|
journal->j_tail, journal->j_tail_sequence,
|
|
journal->j_errno);
|
|
goto out;
|
|
}
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
|
|
journal->j_tail, journal->j_tail_sequence, journal->j_errno);
|
|
|
|
sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
|
|
sb->s_start = cpu_to_be32(journal->j_tail);
|
|
sb->s_errno = cpu_to_be32(journal->j_errno);
|
|
spin_unlock(&journal->j_state_lock);
|
|
|
|
BUFFER_TRACE(bh, "marking dirty");
|
|
mark_buffer_dirty(bh);
|
|
if (wait)
|
|
sync_dirty_buffer(bh);
|
|
else
|
|
ll_rw_block(SWRITE, 1, &bh);
|
|
|
|
out:
|
|
/* If we have just flushed the log (by marking s_start==0), then
|
|
* any future commit will have to be careful to update the
|
|
* superblock again to re-record the true start of the log. */
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
if (sb->s_start)
|
|
journal->j_flags &= ~JBD2_FLUSHED;
|
|
else
|
|
journal->j_flags |= JBD2_FLUSHED;
|
|
spin_unlock(&journal->j_state_lock);
|
|
}
|
|
|
|
/*
|
|
* Read the superblock for a given journal, performing initial
|
|
* validation of the format.
|
|
*/
|
|
|
|
static int journal_get_superblock(journal_t *journal)
|
|
{
|
|
struct buffer_head *bh;
|
|
journal_superblock_t *sb;
|
|
int err = -EIO;
|
|
|
|
bh = journal->j_sb_buffer;
|
|
|
|
J_ASSERT(bh != NULL);
|
|
if (!buffer_uptodate(bh)) {
|
|
ll_rw_block(READ, 1, &bh);
|
|
wait_on_buffer(bh);
|
|
if (!buffer_uptodate(bh)) {
|
|
printk (KERN_ERR
|
|
"JBD: IO error reading journal superblock\n");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
err = -EINVAL;
|
|
|
|
if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
|
|
sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
|
|
printk(KERN_WARNING "JBD: no valid journal superblock found\n");
|
|
goto out;
|
|
}
|
|
|
|
switch(be32_to_cpu(sb->s_header.h_blocktype)) {
|
|
case JBD2_SUPERBLOCK_V1:
|
|
journal->j_format_version = 1;
|
|
break;
|
|
case JBD2_SUPERBLOCK_V2:
|
|
journal->j_format_version = 2;
|
|
break;
|
|
default:
|
|
printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
|
|
goto out;
|
|
}
|
|
|
|
if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
|
|
journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
|
|
else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
|
|
printk (KERN_WARNING "JBD: journal file too short\n");
|
|
goto out;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out:
|
|
journal_fail_superblock(journal);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Load the on-disk journal superblock and read the key fields into the
|
|
* journal_t.
|
|
*/
|
|
|
|
static int load_superblock(journal_t *journal)
|
|
{
|
|
int err;
|
|
journal_superblock_t *sb;
|
|
|
|
err = journal_get_superblock(journal);
|
|
if (err)
|
|
return err;
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
|
|
journal->j_tail = be32_to_cpu(sb->s_start);
|
|
journal->j_first = be32_to_cpu(sb->s_first);
|
|
journal->j_last = be32_to_cpu(sb->s_maxlen);
|
|
journal->j_errno = be32_to_cpu(sb->s_errno);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* int jbd2_journal_load() - Read journal from disk.
|
|
* @journal: Journal to act on.
|
|
*
|
|
* Given a journal_t structure which tells us which disk blocks contain
|
|
* a journal, read the journal from disk to initialise the in-memory
|
|
* structures.
|
|
*/
|
|
int jbd2_journal_load(journal_t *journal)
|
|
{
|
|
int err;
|
|
journal_superblock_t *sb;
|
|
|
|
err = load_superblock(journal);
|
|
if (err)
|
|
return err;
|
|
|
|
sb = journal->j_superblock;
|
|
/* If this is a V2 superblock, then we have to check the
|
|
* features flags on it. */
|
|
|
|
if (journal->j_format_version >= 2) {
|
|
if ((sb->s_feature_ro_compat &
|
|
~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
|
|
(sb->s_feature_incompat &
|
|
~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
|
|
printk (KERN_WARNING
|
|
"JBD: Unrecognised features on journal\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a slab for this blocksize
|
|
*/
|
|
err = jbd2_journal_create_jbd_slab(be32_to_cpu(sb->s_blocksize));
|
|
if (err)
|
|
return err;
|
|
|
|
/* Let the recovery code check whether it needs to recover any
|
|
* data from the journal. */
|
|
if (jbd2_journal_recover(journal))
|
|
goto recovery_error;
|
|
|
|
/* OK, we've finished with the dynamic journal bits:
|
|
* reinitialise the dynamic contents of the superblock in memory
|
|
* and reset them on disk. */
|
|
if (journal_reset(journal))
|
|
goto recovery_error;
|
|
|
|
journal->j_flags &= ~JBD2_ABORT;
|
|
journal->j_flags |= JBD2_LOADED;
|
|
return 0;
|
|
|
|
recovery_error:
|
|
printk (KERN_WARNING "JBD: recovery failed\n");
|
|
return -EIO;
|
|
}
|
|
|
|
/**
|
|
* void jbd2_journal_destroy() - Release a journal_t structure.
|
|
* @journal: Journal to act on.
|
|
*
|
|
* Release a journal_t structure once it is no longer in use by the
|
|
* journaled object.
|
|
*/
|
|
void jbd2_journal_destroy(journal_t *journal)
|
|
{
|
|
/* Wait for the commit thread to wake up and die. */
|
|
journal_kill_thread(journal);
|
|
|
|
/* Force a final log commit */
|
|
if (journal->j_running_transaction)
|
|
jbd2_journal_commit_transaction(journal);
|
|
|
|
/* Force any old transactions to disk */
|
|
|
|
/* Totally anal locking here... */
|
|
spin_lock(&journal->j_list_lock);
|
|
while (journal->j_checkpoint_transactions != NULL) {
|
|
spin_unlock(&journal->j_list_lock);
|
|
jbd2_log_do_checkpoint(journal);
|
|
spin_lock(&journal->j_list_lock);
|
|
}
|
|
|
|
J_ASSERT(journal->j_running_transaction == NULL);
|
|
J_ASSERT(journal->j_committing_transaction == NULL);
|
|
J_ASSERT(journal->j_checkpoint_transactions == NULL);
|
|
spin_unlock(&journal->j_list_lock);
|
|
|
|
/* We can now mark the journal as empty. */
|
|
journal->j_tail = 0;
|
|
journal->j_tail_sequence = ++journal->j_transaction_sequence;
|
|
if (journal->j_sb_buffer) {
|
|
jbd2_journal_update_superblock(journal, 1);
|
|
brelse(journal->j_sb_buffer);
|
|
}
|
|
|
|
if (journal->j_inode)
|
|
iput(journal->j_inode);
|
|
if (journal->j_revoke)
|
|
jbd2_journal_destroy_revoke(journal);
|
|
kfree(journal->j_wbuf);
|
|
kfree(journal);
|
|
}
|
|
|
|
|
|
/**
|
|
*int jbd2_journal_check_used_features () - Check if features specified are used.
|
|
* @journal: Journal to check.
|
|
* @compat: bitmask of compatible features
|
|
* @ro: bitmask of features that force read-only mount
|
|
* @incompat: bitmask of incompatible features
|
|
*
|
|
* Check whether the journal uses all of a given set of
|
|
* features. Return true (non-zero) if it does.
|
|
**/
|
|
|
|
int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
|
|
unsigned long ro, unsigned long incompat)
|
|
{
|
|
journal_superblock_t *sb;
|
|
|
|
if (!compat && !ro && !incompat)
|
|
return 1;
|
|
if (journal->j_format_version == 1)
|
|
return 0;
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
|
|
((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
|
|
((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_check_available_features() - Check feature set in journalling layer
|
|
* @journal: Journal to check.
|
|
* @compat: bitmask of compatible features
|
|
* @ro: bitmask of features that force read-only mount
|
|
* @incompat: bitmask of incompatible features
|
|
*
|
|
* Check whether the journaling code supports the use of
|
|
* all of a given set of features on this journal. Return true
|
|
* (non-zero) if it can. */
|
|
|
|
int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
|
|
unsigned long ro, unsigned long incompat)
|
|
{
|
|
journal_superblock_t *sb;
|
|
|
|
if (!compat && !ro && !incompat)
|
|
return 1;
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
/* We can support any known requested features iff the
|
|
* superblock is in version 2. Otherwise we fail to support any
|
|
* extended sb features. */
|
|
|
|
if (journal->j_format_version != 2)
|
|
return 0;
|
|
|
|
if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
|
|
(ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
|
|
(incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_set_features () - Mark a given journal feature in the superblock
|
|
* @journal: Journal to act on.
|
|
* @compat: bitmask of compatible features
|
|
* @ro: bitmask of features that force read-only mount
|
|
* @incompat: bitmask of incompatible features
|
|
*
|
|
* Mark a given journal feature as present on the
|
|
* superblock. Returns true if the requested features could be set.
|
|
*
|
|
*/
|
|
|
|
int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
|
|
unsigned long ro, unsigned long incompat)
|
|
{
|
|
journal_superblock_t *sb;
|
|
|
|
if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
|
|
return 1;
|
|
|
|
if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
|
|
return 0;
|
|
|
|
jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
|
|
compat, ro, incompat);
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
sb->s_feature_compat |= cpu_to_be32(compat);
|
|
sb->s_feature_ro_compat |= cpu_to_be32(ro);
|
|
sb->s_feature_incompat |= cpu_to_be32(incompat);
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
/**
|
|
* int jbd2_journal_update_format () - Update on-disk journal structure.
|
|
* @journal: Journal to act on.
|
|
*
|
|
* Given an initialised but unloaded journal struct, poke about in the
|
|
* on-disk structure to update it to the most recent supported version.
|
|
*/
|
|
int jbd2_journal_update_format (journal_t *journal)
|
|
{
|
|
journal_superblock_t *sb;
|
|
int err;
|
|
|
|
err = journal_get_superblock(journal);
|
|
if (err)
|
|
return err;
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
switch (be32_to_cpu(sb->s_header.h_blocktype)) {
|
|
case JBD2_SUPERBLOCK_V2:
|
|
return 0;
|
|
case JBD2_SUPERBLOCK_V1:
|
|
return journal_convert_superblock_v1(journal, sb);
|
|
default:
|
|
break;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int journal_convert_superblock_v1(journal_t *journal,
|
|
journal_superblock_t *sb)
|
|
{
|
|
int offset, blocksize;
|
|
struct buffer_head *bh;
|
|
|
|
printk(KERN_WARNING
|
|
"JBD: Converting superblock from version 1 to 2.\n");
|
|
|
|
/* Pre-initialise new fields to zero */
|
|
offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
|
|
blocksize = be32_to_cpu(sb->s_blocksize);
|
|
memset(&sb->s_feature_compat, 0, blocksize-offset);
|
|
|
|
sb->s_nr_users = cpu_to_be32(1);
|
|
sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
|
|
journal->j_format_version = 2;
|
|
|
|
bh = journal->j_sb_buffer;
|
|
BUFFER_TRACE(bh, "marking dirty");
|
|
mark_buffer_dirty(bh);
|
|
sync_dirty_buffer(bh);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* int jbd2_journal_flush () - Flush journal
|
|
* @journal: Journal to act on.
|
|
*
|
|
* Flush all data for a given journal to disk and empty the journal.
|
|
* Filesystems can use this when remounting readonly to ensure that
|
|
* recovery does not need to happen on remount.
|
|
*/
|
|
|
|
int jbd2_journal_flush(journal_t *journal)
|
|
{
|
|
int err = 0;
|
|
transaction_t *transaction = NULL;
|
|
unsigned long old_tail;
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
|
|
/* Force everything buffered to the log... */
|
|
if (journal->j_running_transaction) {
|
|
transaction = journal->j_running_transaction;
|
|
__jbd2_log_start_commit(journal, transaction->t_tid);
|
|
} else if (journal->j_committing_transaction)
|
|
transaction = journal->j_committing_transaction;
|
|
|
|
/* Wait for the log commit to complete... */
|
|
if (transaction) {
|
|
tid_t tid = transaction->t_tid;
|
|
|
|
spin_unlock(&journal->j_state_lock);
|
|
jbd2_log_wait_commit(journal, tid);
|
|
} else {
|
|
spin_unlock(&journal->j_state_lock);
|
|
}
|
|
|
|
/* ...and flush everything in the log out to disk. */
|
|
spin_lock(&journal->j_list_lock);
|
|
while (!err && journal->j_checkpoint_transactions != NULL) {
|
|
spin_unlock(&journal->j_list_lock);
|
|
err = jbd2_log_do_checkpoint(journal);
|
|
spin_lock(&journal->j_list_lock);
|
|
}
|
|
spin_unlock(&journal->j_list_lock);
|
|
jbd2_cleanup_journal_tail(journal);
|
|
|
|
/* Finally, mark the journal as really needing no recovery.
|
|
* This sets s_start==0 in the underlying superblock, which is
|
|
* the magic code for a fully-recovered superblock. Any future
|
|
* commits of data to the journal will restore the current
|
|
* s_start value. */
|
|
spin_lock(&journal->j_state_lock);
|
|
old_tail = journal->j_tail;
|
|
journal->j_tail = 0;
|
|
spin_unlock(&journal->j_state_lock);
|
|
jbd2_journal_update_superblock(journal, 1);
|
|
spin_lock(&journal->j_state_lock);
|
|
journal->j_tail = old_tail;
|
|
|
|
J_ASSERT(!journal->j_running_transaction);
|
|
J_ASSERT(!journal->j_committing_transaction);
|
|
J_ASSERT(!journal->j_checkpoint_transactions);
|
|
J_ASSERT(journal->j_head == journal->j_tail);
|
|
J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
|
|
spin_unlock(&journal->j_state_lock);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_wipe() - Wipe journal contents
|
|
* @journal: Journal to act on.
|
|
* @write: flag (see below)
|
|
*
|
|
* Wipe out all of the contents of a journal, safely. This will produce
|
|
* a warning if the journal contains any valid recovery information.
|
|
* Must be called between journal_init_*() and jbd2_journal_load().
|
|
*
|
|
* If 'write' is non-zero, then we wipe out the journal on disk; otherwise
|
|
* we merely suppress recovery.
|
|
*/
|
|
|
|
int jbd2_journal_wipe(journal_t *journal, int write)
|
|
{
|
|
journal_superblock_t *sb;
|
|
int err = 0;
|
|
|
|
J_ASSERT (!(journal->j_flags & JBD2_LOADED));
|
|
|
|
err = load_superblock(journal);
|
|
if (err)
|
|
return err;
|
|
|
|
sb = journal->j_superblock;
|
|
|
|
if (!journal->j_tail)
|
|
goto no_recovery;
|
|
|
|
printk (KERN_WARNING "JBD: %s recovery information on journal\n",
|
|
write ? "Clearing" : "Ignoring");
|
|
|
|
err = jbd2_journal_skip_recovery(journal);
|
|
if (write)
|
|
jbd2_journal_update_superblock(journal, 1);
|
|
|
|
no_recovery:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* journal_dev_name: format a character string to describe on what
|
|
* device this journal is present.
|
|
*/
|
|
|
|
static const char *journal_dev_name(journal_t *journal, char *buffer)
|
|
{
|
|
struct block_device *bdev;
|
|
|
|
if (journal->j_inode)
|
|
bdev = journal->j_inode->i_sb->s_bdev;
|
|
else
|
|
bdev = journal->j_dev;
|
|
|
|
return bdevname(bdev, buffer);
|
|
}
|
|
|
|
/*
|
|
* Journal abort has very specific semantics, which we describe
|
|
* for journal abort.
|
|
*
|
|
* Two internal function, which provide abort to te jbd layer
|
|
* itself are here.
|
|
*/
|
|
|
|
/*
|
|
* Quick version for internal journal use (doesn't lock the journal).
|
|
* Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
|
|
* and don't attempt to make any other journal updates.
|
|
*/
|
|
void __jbd2_journal_abort_hard(journal_t *journal)
|
|
{
|
|
transaction_t *transaction;
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
if (journal->j_flags & JBD2_ABORT)
|
|
return;
|
|
|
|
printk(KERN_ERR "Aborting journal on device %s.\n",
|
|
journal_dev_name(journal, b));
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
journal->j_flags |= JBD2_ABORT;
|
|
transaction = journal->j_running_transaction;
|
|
if (transaction)
|
|
__jbd2_log_start_commit(journal, transaction->t_tid);
|
|
spin_unlock(&journal->j_state_lock);
|
|
}
|
|
|
|
/* Soft abort: record the abort error status in the journal superblock,
|
|
* but don't do any other IO. */
|
|
static void __journal_abort_soft (journal_t *journal, int errno)
|
|
{
|
|
if (journal->j_flags & JBD2_ABORT)
|
|
return;
|
|
|
|
if (!journal->j_errno)
|
|
journal->j_errno = errno;
|
|
|
|
__jbd2_journal_abort_hard(journal);
|
|
|
|
if (errno)
|
|
jbd2_journal_update_superblock(journal, 1);
|
|
}
|
|
|
|
/**
|
|
* void jbd2_journal_abort () - Shutdown the journal immediately.
|
|
* @journal: the journal to shutdown.
|
|
* @errno: an error number to record in the journal indicating
|
|
* the reason for the shutdown.
|
|
*
|
|
* Perform a complete, immediate shutdown of the ENTIRE
|
|
* journal (not of a single transaction). This operation cannot be
|
|
* undone without closing and reopening the journal.
|
|
*
|
|
* The jbd2_journal_abort function is intended to support higher level error
|
|
* recovery mechanisms such as the ext2/ext3 remount-readonly error
|
|
* mode.
|
|
*
|
|
* Journal abort has very specific semantics. Any existing dirty,
|
|
* unjournaled buffers in the main filesystem will still be written to
|
|
* disk by bdflush, but the journaling mechanism will be suspended
|
|
* immediately and no further transaction commits will be honoured.
|
|
*
|
|
* Any dirty, journaled buffers will be written back to disk without
|
|
* hitting the journal. Atomicity cannot be guaranteed on an aborted
|
|
* filesystem, but we _do_ attempt to leave as much data as possible
|
|
* behind for fsck to use for cleanup.
|
|
*
|
|
* Any attempt to get a new transaction handle on a journal which is in
|
|
* ABORT state will just result in an -EROFS error return. A
|
|
* jbd2_journal_stop on an existing handle will return -EIO if we have
|
|
* entered abort state during the update.
|
|
*
|
|
* Recursive transactions are not disturbed by journal abort until the
|
|
* final jbd2_journal_stop, which will receive the -EIO error.
|
|
*
|
|
* Finally, the jbd2_journal_abort call allows the caller to supply an errno
|
|
* which will be recorded (if possible) in the journal superblock. This
|
|
* allows a client to record failure conditions in the middle of a
|
|
* transaction without having to complete the transaction to record the
|
|
* failure to disk. ext3_error, for example, now uses this
|
|
* functionality.
|
|
*
|
|
* Errors which originate from within the journaling layer will NOT
|
|
* supply an errno; a null errno implies that absolutely no further
|
|
* writes are done to the journal (unless there are any already in
|
|
* progress).
|
|
*
|
|
*/
|
|
|
|
void jbd2_journal_abort(journal_t *journal, int errno)
|
|
{
|
|
__journal_abort_soft(journal, errno);
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_errno () - returns the journal's error state.
|
|
* @journal: journal to examine.
|
|
*
|
|
* This is the errno numbet set with jbd2_journal_abort(), the last
|
|
* time the journal was mounted - if the journal was stopped
|
|
* without calling abort this will be 0.
|
|
*
|
|
* If the journal has been aborted on this mount time -EROFS will
|
|
* be returned.
|
|
*/
|
|
int jbd2_journal_errno(journal_t *journal)
|
|
{
|
|
int err;
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
if (journal->j_flags & JBD2_ABORT)
|
|
err = -EROFS;
|
|
else
|
|
err = journal->j_errno;
|
|
spin_unlock(&journal->j_state_lock);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* int jbd2_journal_clear_err () - clears the journal's error state
|
|
* @journal: journal to act on.
|
|
*
|
|
* An error must be cleared or Acked to take a FS out of readonly
|
|
* mode.
|
|
*/
|
|
int jbd2_journal_clear_err(journal_t *journal)
|
|
{
|
|
int err = 0;
|
|
|
|
spin_lock(&journal->j_state_lock);
|
|
if (journal->j_flags & JBD2_ABORT)
|
|
err = -EROFS;
|
|
else
|
|
journal->j_errno = 0;
|
|
spin_unlock(&journal->j_state_lock);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* void jbd2_journal_ack_err() - Ack journal err.
|
|
* @journal: journal to act on.
|
|
*
|
|
* An error must be cleared or Acked to take a FS out of readonly
|
|
* mode.
|
|
*/
|
|
void jbd2_journal_ack_err(journal_t *journal)
|
|
{
|
|
spin_lock(&journal->j_state_lock);
|
|
if (journal->j_errno)
|
|
journal->j_flags |= JBD2_ACK_ERR;
|
|
spin_unlock(&journal->j_state_lock);
|
|
}
|
|
|
|
int jbd2_journal_blocks_per_page(struct inode *inode)
|
|
{
|
|
return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
|
|
}
|
|
|
|
/*
|
|
* helper functions to deal with 32 or 64bit block numbers.
|
|
*/
|
|
size_t journal_tag_bytes(journal_t *journal)
|
|
{
|
|
if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
|
|
return JBD_TAG_SIZE64;
|
|
else
|
|
return JBD_TAG_SIZE32;
|
|
}
|
|
|
|
/*
|
|
* Simple support for retrying memory allocations. Introduced to help to
|
|
* debug different VM deadlock avoidance strategies.
|
|
*/
|
|
void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry)
|
|
{
|
|
return kmalloc(size, flags | (retry ? __GFP_NOFAIL : 0));
|
|
}
|
|
|
|
/*
|
|
* jbd slab management: create 1k, 2k, 4k, 8k slabs as needed
|
|
* and allocate frozen and commit buffers from these slabs.
|
|
*
|
|
* Reason for doing this is to avoid, SLAB_DEBUG - since it could
|
|
* cause bh to cross page boundary.
|
|
*/
|
|
|
|
#define JBD_MAX_SLABS 5
|
|
#define JBD_SLAB_INDEX(size) (size >> 11)
|
|
|
|
static struct kmem_cache *jbd_slab[JBD_MAX_SLABS];
|
|
static const char *jbd_slab_names[JBD_MAX_SLABS] = {
|
|
"jbd2_1k", "jbd2_2k", "jbd2_4k", NULL, "jbd2_8k"
|
|
};
|
|
|
|
static void jbd2_journal_destroy_jbd_slabs(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < JBD_MAX_SLABS; i++) {
|
|
if (jbd_slab[i])
|
|
kmem_cache_destroy(jbd_slab[i]);
|
|
jbd_slab[i] = NULL;
|
|
}
|
|
}
|
|
|
|
static int jbd2_journal_create_jbd_slab(size_t slab_size)
|
|
{
|
|
int i = JBD_SLAB_INDEX(slab_size);
|
|
|
|
BUG_ON(i >= JBD_MAX_SLABS);
|
|
|
|
/*
|
|
* Check if we already have a slab created for this size
|
|
*/
|
|
if (jbd_slab[i])
|
|
return 0;
|
|
|
|
/*
|
|
* Create a slab and force alignment to be same as slabsize -
|
|
* this will make sure that allocations won't cross the page
|
|
* boundary.
|
|
*/
|
|
jbd_slab[i] = kmem_cache_create(jbd_slab_names[i],
|
|
slab_size, slab_size, 0, NULL, NULL);
|
|
if (!jbd_slab[i]) {
|
|
printk(KERN_EMERG "JBD: no memory for jbd_slab cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void * jbd2_slab_alloc(size_t size, gfp_t flags)
|
|
{
|
|
int idx;
|
|
|
|
idx = JBD_SLAB_INDEX(size);
|
|
BUG_ON(jbd_slab[idx] == NULL);
|
|
return kmem_cache_alloc(jbd_slab[idx], flags | __GFP_NOFAIL);
|
|
}
|
|
|
|
void jbd2_slab_free(void *ptr, size_t size)
|
|
{
|
|
int idx;
|
|
|
|
idx = JBD_SLAB_INDEX(size);
|
|
BUG_ON(jbd_slab[idx] == NULL);
|
|
kmem_cache_free(jbd_slab[idx], ptr);
|
|
}
|
|
|
|
/*
|
|
* Journal_head storage management
|
|
*/
|
|
static struct kmem_cache *jbd2_journal_head_cache;
|
|
#ifdef CONFIG_JBD_DEBUG
|
|
static atomic_t nr_journal_heads = ATOMIC_INIT(0);
|
|
#endif
|
|
|
|
static int journal_init_jbd2_journal_head_cache(void)
|
|
{
|
|
int retval;
|
|
|
|
J_ASSERT(jbd2_journal_head_cache == 0);
|
|
jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
|
|
sizeof(struct journal_head),
|
|
0, /* offset */
|
|
0, /* flags */
|
|
NULL, /* ctor */
|
|
NULL); /* dtor */
|
|
retval = 0;
|
|
if (jbd2_journal_head_cache == 0) {
|
|
retval = -ENOMEM;
|
|
printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
|
|
{
|
|
J_ASSERT(jbd2_journal_head_cache != NULL);
|
|
kmem_cache_destroy(jbd2_journal_head_cache);
|
|
jbd2_journal_head_cache = NULL;
|
|
}
|
|
|
|
/*
|
|
* journal_head splicing and dicing
|
|
*/
|
|
static struct journal_head *journal_alloc_journal_head(void)
|
|
{
|
|
struct journal_head *ret;
|
|
static unsigned long last_warning;
|
|
|
|
#ifdef CONFIG_JBD_DEBUG
|
|
atomic_inc(&nr_journal_heads);
|
|
#endif
|
|
ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
|
|
if (ret == 0) {
|
|
jbd_debug(1, "out of memory for journal_head\n");
|
|
if (time_after(jiffies, last_warning + 5*HZ)) {
|
|
printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
|
|
__FUNCTION__);
|
|
last_warning = jiffies;
|
|
}
|
|
while (ret == 0) {
|
|
yield();
|
|
ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void journal_free_journal_head(struct journal_head *jh)
|
|
{
|
|
#ifdef CONFIG_JBD_DEBUG
|
|
atomic_dec(&nr_journal_heads);
|
|
memset(jh, JBD_POISON_FREE, sizeof(*jh));
|
|
#endif
|
|
kmem_cache_free(jbd2_journal_head_cache, jh);
|
|
}
|
|
|
|
/*
|
|
* A journal_head is attached to a buffer_head whenever JBD has an
|
|
* interest in the buffer.
|
|
*
|
|
* Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
|
|
* is set. This bit is tested in core kernel code where we need to take
|
|
* JBD-specific actions. Testing the zeroness of ->b_private is not reliable
|
|
* there.
|
|
*
|
|
* When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
|
|
*
|
|
* When a buffer has its BH_JBD bit set it is immune from being released by
|
|
* core kernel code, mainly via ->b_count.
|
|
*
|
|
* A journal_head may be detached from its buffer_head when the journal_head's
|
|
* b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
|
|
* Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
|
|
* journal_head can be dropped if needed.
|
|
*
|
|
* Various places in the kernel want to attach a journal_head to a buffer_head
|
|
* _before_ attaching the journal_head to a transaction. To protect the
|
|
* journal_head in this situation, jbd2_journal_add_journal_head elevates the
|
|
* journal_head's b_jcount refcount by one. The caller must call
|
|
* jbd2_journal_put_journal_head() to undo this.
|
|
*
|
|
* So the typical usage would be:
|
|
*
|
|
* (Attach a journal_head if needed. Increments b_jcount)
|
|
* struct journal_head *jh = jbd2_journal_add_journal_head(bh);
|
|
* ...
|
|
* jh->b_transaction = xxx;
|
|
* jbd2_journal_put_journal_head(jh);
|
|
*
|
|
* Now, the journal_head's b_jcount is zero, but it is safe from being released
|
|
* because it has a non-zero b_transaction.
|
|
*/
|
|
|
|
/*
|
|
* Give a buffer_head a journal_head.
|
|
*
|
|
* Doesn't need the journal lock.
|
|
* May sleep.
|
|
*/
|
|
struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
|
|
{
|
|
struct journal_head *jh;
|
|
struct journal_head *new_jh = NULL;
|
|
|
|
repeat:
|
|
if (!buffer_jbd(bh)) {
|
|
new_jh = journal_alloc_journal_head();
|
|
memset(new_jh, 0, sizeof(*new_jh));
|
|
}
|
|
|
|
jbd_lock_bh_journal_head(bh);
|
|
if (buffer_jbd(bh)) {
|
|
jh = bh2jh(bh);
|
|
} else {
|
|
J_ASSERT_BH(bh,
|
|
(atomic_read(&bh->b_count) > 0) ||
|
|
(bh->b_page && bh->b_page->mapping));
|
|
|
|
if (!new_jh) {
|
|
jbd_unlock_bh_journal_head(bh);
|
|
goto repeat;
|
|
}
|
|
|
|
jh = new_jh;
|
|
new_jh = NULL; /* We consumed it */
|
|
set_buffer_jbd(bh);
|
|
bh->b_private = jh;
|
|
jh->b_bh = bh;
|
|
get_bh(bh);
|
|
BUFFER_TRACE(bh, "added journal_head");
|
|
}
|
|
jh->b_jcount++;
|
|
jbd_unlock_bh_journal_head(bh);
|
|
if (new_jh)
|
|
journal_free_journal_head(new_jh);
|
|
return bh->b_private;
|
|
}
|
|
|
|
/*
|
|
* Grab a ref against this buffer_head's journal_head. If it ended up not
|
|
* having a journal_head, return NULL
|
|
*/
|
|
struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
|
|
{
|
|
struct journal_head *jh = NULL;
|
|
|
|
jbd_lock_bh_journal_head(bh);
|
|
if (buffer_jbd(bh)) {
|
|
jh = bh2jh(bh);
|
|
jh->b_jcount++;
|
|
}
|
|
jbd_unlock_bh_journal_head(bh);
|
|
return jh;
|
|
}
|
|
|
|
static void __journal_remove_journal_head(struct buffer_head *bh)
|
|
{
|
|
struct journal_head *jh = bh2jh(bh);
|
|
|
|
J_ASSERT_JH(jh, jh->b_jcount >= 0);
|
|
|
|
get_bh(bh);
|
|
if (jh->b_jcount == 0) {
|
|
if (jh->b_transaction == NULL &&
|
|
jh->b_next_transaction == NULL &&
|
|
jh->b_cp_transaction == NULL) {
|
|
J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
|
|
J_ASSERT_BH(bh, buffer_jbd(bh));
|
|
J_ASSERT_BH(bh, jh2bh(jh) == bh);
|
|
BUFFER_TRACE(bh, "remove journal_head");
|
|
if (jh->b_frozen_data) {
|
|
printk(KERN_WARNING "%s: freeing "
|
|
"b_frozen_data\n",
|
|
__FUNCTION__);
|
|
jbd2_slab_free(jh->b_frozen_data, bh->b_size);
|
|
}
|
|
if (jh->b_committed_data) {
|
|
printk(KERN_WARNING "%s: freeing "
|
|
"b_committed_data\n",
|
|
__FUNCTION__);
|
|
jbd2_slab_free(jh->b_committed_data, bh->b_size);
|
|
}
|
|
bh->b_private = NULL;
|
|
jh->b_bh = NULL; /* debug, really */
|
|
clear_buffer_jbd(bh);
|
|
__brelse(bh);
|
|
journal_free_journal_head(jh);
|
|
} else {
|
|
BUFFER_TRACE(bh, "journal_head was locked");
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
|
|
* and has a zero b_jcount then remove and release its journal_head. If we did
|
|
* see that the buffer is not used by any transaction we also "logically"
|
|
* decrement ->b_count.
|
|
*
|
|
* We in fact take an additional increment on ->b_count as a convenience,
|
|
* because the caller usually wants to do additional things with the bh
|
|
* after calling here.
|
|
* The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
|
|
* time. Once the caller has run __brelse(), the buffer is eligible for
|
|
* reaping by try_to_free_buffers().
|
|
*/
|
|
void jbd2_journal_remove_journal_head(struct buffer_head *bh)
|
|
{
|
|
jbd_lock_bh_journal_head(bh);
|
|
__journal_remove_journal_head(bh);
|
|
jbd_unlock_bh_journal_head(bh);
|
|
}
|
|
|
|
/*
|
|
* Drop a reference on the passed journal_head. If it fell to zero then try to
|
|
* release the journal_head from the buffer_head.
|
|
*/
|
|
void jbd2_journal_put_journal_head(struct journal_head *jh)
|
|
{
|
|
struct buffer_head *bh = jh2bh(jh);
|
|
|
|
jbd_lock_bh_journal_head(bh);
|
|
J_ASSERT_JH(jh, jh->b_jcount > 0);
|
|
--jh->b_jcount;
|
|
if (!jh->b_jcount && !jh->b_transaction) {
|
|
__journal_remove_journal_head(bh);
|
|
__brelse(bh);
|
|
}
|
|
jbd_unlock_bh_journal_head(bh);
|
|
}
|
|
|
|
/*
|
|
* /proc tunables
|
|
*/
|
|
#if defined(CONFIG_JBD_DEBUG)
|
|
int jbd2_journal_enable_debug;
|
|
EXPORT_SYMBOL(jbd2_journal_enable_debug);
|
|
#endif
|
|
|
|
#if defined(CONFIG_JBD_DEBUG) && defined(CONFIG_PROC_FS)
|
|
|
|
static struct proc_dir_entry *proc_jbd_debug;
|
|
|
|
static int read_jbd_debug(char *page, char **start, off_t off,
|
|
int count, int *eof, void *data)
|
|
{
|
|
int ret;
|
|
|
|
ret = sprintf(page + off, "%d\n", jbd2_journal_enable_debug);
|
|
*eof = 1;
|
|
return ret;
|
|
}
|
|
|
|
static int write_jbd_debug(struct file *file, const char __user *buffer,
|
|
unsigned long count, void *data)
|
|
{
|
|
char buf[32];
|
|
|
|
if (count > ARRAY_SIZE(buf) - 1)
|
|
count = ARRAY_SIZE(buf) - 1;
|
|
if (copy_from_user(buf, buffer, count))
|
|
return -EFAULT;
|
|
buf[ARRAY_SIZE(buf) - 1] = '\0';
|
|
jbd2_journal_enable_debug = simple_strtoul(buf, NULL, 10);
|
|
return count;
|
|
}
|
|
|
|
#define JBD_PROC_NAME "sys/fs/jbd2-debug"
|
|
|
|
static void __init create_jbd_proc_entry(void)
|
|
{
|
|
proc_jbd_debug = create_proc_entry(JBD_PROC_NAME, 0644, NULL);
|
|
if (proc_jbd_debug) {
|
|
/* Why is this so hard? */
|
|
proc_jbd_debug->read_proc = read_jbd_debug;
|
|
proc_jbd_debug->write_proc = write_jbd_debug;
|
|
}
|
|
}
|
|
|
|
static void __exit jbd2_remove_jbd_proc_entry(void)
|
|
{
|
|
if (proc_jbd_debug)
|
|
remove_proc_entry(JBD_PROC_NAME, NULL);
|
|
}
|
|
|
|
#else
|
|
|
|
#define create_jbd_proc_entry() do {} while (0)
|
|
#define jbd2_remove_jbd_proc_entry() do {} while (0)
|
|
|
|
#endif
|
|
|
|
struct kmem_cache *jbd2_handle_cache;
|
|
|
|
static int __init journal_init_handle_cache(void)
|
|
{
|
|
jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
|
|
sizeof(handle_t),
|
|
0, /* offset */
|
|
0, /* flags */
|
|
NULL, /* ctor */
|
|
NULL); /* dtor */
|
|
if (jbd2_handle_cache == NULL) {
|
|
printk(KERN_EMERG "JBD: failed to create handle cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void jbd2_journal_destroy_handle_cache(void)
|
|
{
|
|
if (jbd2_handle_cache)
|
|
kmem_cache_destroy(jbd2_handle_cache);
|
|
}
|
|
|
|
/*
|
|
* Module startup and shutdown
|
|
*/
|
|
|
|
static int __init journal_init_caches(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = jbd2_journal_init_revoke_caches();
|
|
if (ret == 0)
|
|
ret = journal_init_jbd2_journal_head_cache();
|
|
if (ret == 0)
|
|
ret = journal_init_handle_cache();
|
|
return ret;
|
|
}
|
|
|
|
static void jbd2_journal_destroy_caches(void)
|
|
{
|
|
jbd2_journal_destroy_revoke_caches();
|
|
jbd2_journal_destroy_jbd2_journal_head_cache();
|
|
jbd2_journal_destroy_handle_cache();
|
|
jbd2_journal_destroy_jbd_slabs();
|
|
}
|
|
|
|
static int __init journal_init(void)
|
|
{
|
|
int ret;
|
|
|
|
BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
|
|
|
|
ret = journal_init_caches();
|
|
if (ret != 0)
|
|
jbd2_journal_destroy_caches();
|
|
create_jbd_proc_entry();
|
|
return ret;
|
|
}
|
|
|
|
static void __exit journal_exit(void)
|
|
{
|
|
#ifdef CONFIG_JBD_DEBUG
|
|
int n = atomic_read(&nr_journal_heads);
|
|
if (n)
|
|
printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
|
|
#endif
|
|
jbd2_remove_jbd_proc_entry();
|
|
jbd2_journal_destroy_caches();
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
module_init(journal_init);
|
|
module_exit(journal_exit);
|
|
|