/*
- * linux/fs/checkpoint.c
- *
+ * linux/fs/jbd/checkpoint.c
+ *
* Written by Stephen C. Tweedie <sct@redhat.com>, 1999
*
* Copyright 1999 Red Hat Software --- All Rights Reserved
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*
- * Checkpoint routines for the generic filesystem journaling code.
- * Part of the ext2fs journaling system.
+ * Checkpoint routines for the generic filesystem journaling code.
+ * Part of the ext2fs journaling system.
*
* Checkpointing is the process of ensuring that a section of the log is
* committed fully to disk, so that that portion of the log can be
*
* Called with j_list_lock held.
*/
-
-static void __buffer_unlink_first(struct journal_head *jh)
+static inline void __buffer_unlink_first(struct journal_head *jh)
{
- transaction_t *transaction;
-
- transaction = jh->b_cp_transaction;
+ transaction_t *transaction = jh->b_cp_transaction;
jh->b_cpnext->b_cpprev = jh->b_cpprev;
jh->b_cpprev->b_cpnext = jh->b_cpnext;
*
* Called with j_list_lock held.
*/
-
static inline void __buffer_unlink(struct journal_head *jh)
{
- transaction_t *transaction;
-
- transaction = jh->b_cp_transaction;
+ transaction_t *transaction = jh->b_cp_transaction;
__buffer_unlink_first(jh);
if (transaction->t_checkpoint_io_list == jh) {
*
* Called with j_list_lock held
*/
-
static inline void __buffer_relink_io(struct journal_head *jh)
{
- transaction_t *transaction;
+ transaction_t *transaction = jh->b_cp_transaction;
- transaction = jh->b_cp_transaction;
__buffer_unlink_first(jh);
if (!transaction->t_checkpoint_io_list) {
int ret = 0;
struct buffer_head *bh = jh2bh(jh);
- if (jh->b_jlist == BJ_None && !buffer_locked(bh) && !buffer_dirty(bh)) {
+ if (jh->b_jlist == BJ_None && !buffer_locked(bh) &&
+ !buffer_dirty(bh) && !buffer_write_io_error(bh)) {
JBUFFER_TRACE(jh, "remove from checkpoint list");
ret = __journal_remove_checkpoint(jh) + 1;
jbd_unlock_bh_state(bh);
*/
void __log_wait_for_space(journal_t *journal)
{
- int nblocks;
+ int nblocks, space_left;
assert_spin_locked(&journal->j_state_lock);
nblocks = jbd_space_needed(journal);
if (journal->j_flags & JFS_ABORT)
return;
spin_unlock(&journal->j_state_lock);
- down(&journal->j_checkpoint_sem);
+ mutex_lock(&journal->j_checkpoint_mutex);
/*
* Test again, another process may have checkpointed while we
- * were waiting for the checkpoint lock
+ * were waiting for the checkpoint lock. If there are no
+ * transactions ready to be checkpointed, try to recover
+ * journal space by calling cleanup_journal_tail(), and if
+ * that doesn't work, by waiting for the currently committing
+ * transaction to complete. If there is absolutely no way
+ * to make progress, this is either a BUG or corrupted
+ * filesystem, so abort the journal and leave a stack
+ * trace for forensic evidence.
*/
spin_lock(&journal->j_state_lock);
+ spin_lock(&journal->j_list_lock);
nblocks = jbd_space_needed(journal);
- if (__log_space_left(journal) < nblocks) {
+ space_left = __log_space_left(journal);
+ if (space_left < nblocks) {
+ int chkpt = journal->j_checkpoint_transactions != NULL;
+ tid_t tid = 0;
+
+ if (journal->j_committing_transaction)
+ tid = journal->j_committing_transaction->t_tid;
+ spin_unlock(&journal->j_list_lock);
spin_unlock(&journal->j_state_lock);
- log_do_checkpoint(journal);
+ if (chkpt) {
+ log_do_checkpoint(journal);
+ } else if (cleanup_journal_tail(journal) == 0) {
+ /* We were able to recover space; yay! */
+ ;
+ } else if (tid) {
+ log_wait_commit(journal, tid);
+ } else {
+ printk(KERN_ERR "%s: needed %d blocks and "
+ "only had %d space available\n",
+ __func__, nblocks, space_left);
+ printk(KERN_ERR "%s: no way to get more "
+ "journal space\n", __func__);
+ WARN_ON(1);
+ journal_abort(journal, 0);
+ }
spin_lock(&journal->j_state_lock);
+ } else {
+ spin_unlock(&journal->j_list_lock);
}
- up(&journal->j_checkpoint_sem);
+ mutex_unlock(&journal->j_checkpoint_mutex);
}
}
* jbd_unlock_bh_state().
*/
static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh)
+ __releases(journal->j_list_lock)
{
get_bh(bh);
spin_unlock(&journal->j_list_lock);
* buffers. Note that we take the buffers in the opposite ordering
* from the one in which they were submitted for IO.
*
+ * Return 0 on success, and return <0 if some buffers have failed
+ * to be written out.
+ *
* Called with j_list_lock held.
*/
-
-static void __wait_cp_io(journal_t *journal, transaction_t *transaction)
+static int __wait_cp_io(journal_t *journal, transaction_t *transaction)
{
struct journal_head *jh;
struct buffer_head *bh;
tid_t this_tid;
int released = 0;
+ int ret = 0;
this_tid = transaction->t_tid;
restart:
- /* Didn't somebody clean up the transaction in the meanwhile */
+ /* Did somebody clean up the transaction in the meanwhile? */
if (journal->j_checkpoint_transactions != transaction ||
- transaction->t_tid != this_tid)
- return;
+ transaction->t_tid != this_tid)
+ return ret;
while (!released && transaction->t_checkpoint_io_list) {
jh = transaction->t_checkpoint_io_list;
bh = jh2bh(jh);
spin_lock(&journal->j_list_lock);
goto restart;
}
+ if (unlikely(buffer_write_io_error(bh)))
+ ret = -EIO;
+
/*
* Now in whatever state the buffer currently is, we know that
* it has been written out and so we can drop it from the list
*/
released = __journal_remove_checkpoint(jh);
jbd_unlock_bh_state(bh);
+ journal_remove_journal_head(bh);
+ __brelse(bh);
}
+
+ return ret;
}
#define NR_BATCH 64
* Try to flush one buffer from the checkpoint list to disk.
*
* Return 1 if something happened which requires us to abort the current
- * scan of the checkpoint list.
+ * scan of the checkpoint list. Return <0 if the buffer has failed to
+ * be written out.
*
* Called with j_list_lock held and drops it if 1 is returned
* Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
int ret = 0;
if (buffer_locked(bh)) {
- get_bh(bh);
+ atomic_inc(&bh->b_count);
spin_unlock(&journal->j_list_lock);
jbd_unlock_bh_state(bh);
wait_on_buffer(bh);
/* the journal_head may have gone by now */
BUFFER_TRACE(bh, "brelse");
- put_bh(bh);
+ __brelse(bh);
ret = 1;
- }
- else if (jh->b_transaction != NULL) {
+ } else if (jh->b_transaction != NULL) {
transaction_t *t = jh->b_transaction;
tid_t tid = t->t_tid;
log_start_commit(journal, tid);
log_wait_commit(journal, tid);
ret = 1;
- }
- else if (!buffer_dirty(bh)) {
+ } else if (!buffer_dirty(bh)) {
+ ret = 1;
+ if (unlikely(buffer_write_io_error(bh)))
+ ret = -EIO;
J_ASSERT_JH(jh, !buffer_jbddirty(bh));
BUFFER_TRACE(bh, "remove from checkpoint");
__journal_remove_checkpoint(jh);
spin_unlock(&journal->j_list_lock);
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh);
- put_bh(bh);
- ret = 1;
- }
- else {
+ __brelse(bh);
+ } else {
/*
* Important: we are about to write the buffer, and
* possibly block, while still holding the journal lock.
* We cannot afford to let the transaction logic start
* messing around with this buffer before we write it to
- * disk, as that would break recoverability.
+ * disk, as that would break recoverability.
*/
BUFFER_TRACE(bh, "queue");
get_bh(bh);
* Perform an actual checkpoint. We take the first transaction on the
* list of transactions to be checkpointed and send all its buffers
* to disk. We submit larger chunks of data at once.
- *
+ *
* The journal should be locked before calling this function.
+ * Called with j_checkpoint_mutex held.
*/
int log_do_checkpoint(journal_t *journal)
{
jbd_debug(1, "Start checkpoint\n");
- /*
+ /*
* First thing: if there are any transactions in the log which
* don't need checkpointing, just eliminate them from the
- * journal straight away.
+ * journal straight away.
*/
result = cleanup_journal_tail(journal);
jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
* OK, we need to start writing disk blocks. Take one transaction
* and write it.
*/
+ result = 0;
spin_lock(&journal->j_list_lock);
if (!journal->j_checkpoint_transactions)
goto out;
* done (maybe it's a new transaction, but it fell at the same
* address).
*/
- if (journal->j_checkpoint_transactions == transaction &&
+ if (journal->j_checkpoint_transactions == transaction &&
transaction->t_tid == this_tid) {
int batch_count = 0;
struct buffer_head *bhs[NR_BATCH];
struct journal_head *jh;
- int retry = 0;
+ int retry = 0, err;
while (!retry && transaction->t_checkpoint_list) {
struct buffer_head *bh;
retry = 1;
break;
}
- retry = __process_buffer(journal, jh, bhs,
- &batch_count);
- if (!retry &&
- lock_need_resched(&journal->j_list_lock)) {
+ retry = __process_buffer(journal, jh, bhs,&batch_count);
+ if (retry < 0 && !result)
+ result = retry;
+ if (!retry && (need_resched() ||
+ spin_needbreak(&journal->j_list_lock))) {
spin_unlock(&journal->j_list_lock);
retry = 1;
break;
}
/*
* Now we have cleaned up the first transaction's checkpoint
- * list. Let's clean up the second one.
+ * list. Let's clean up the second one
*/
- __wait_cp_io(journal, transaction);
+ err = __wait_cp_io(journal, transaction);
+ if (!result)
+ result = err;
}
out:
spin_unlock(&journal->j_list_lock);
- result = cleanup_journal_tail(journal);
if (result < 0)
- return result;
- return 0;
+ journal_abort(journal, result);
+ else
+ result = cleanup_journal_tail(journal);
+
+ return (result < 0) ? result : 0;
}
/*
* we have already got rid of any since the last update of the log tail
* in the journal superblock. If so, we can instantly roll the
* superblock forward to remove those transactions from the log.
- *
+ *
* Return <0 on error, 0 on success, 1 if there was nothing to clean up.
- *
+ *
* Called with the journal lock held.
*
* This is the only part of the journaling code which really needs to be
* aware of transaction aborts. Checkpointing involves writing to the
* main filesystem area rather than to the journal, so it can proceed
- * even in abort state, but we must not update the journal superblock if
- * we have an abort error outstanding.
+ * even in abort state, but we must not update the super block if
+ * checkpointing may have failed. Otherwise, we would lose some metadata
+ * buffers which should be written-back to the filesystem.
*/
int cleanup_journal_tail(journal_t *journal)
{
transaction_t * transaction;
tid_t first_tid;
- unsigned long blocknr, freed;
+ unsigned int blocknr, freed;
+
+ if (is_journal_aborted(journal))
+ return 1;
/* OK, work out the oldest transaction remaining in the log, and
- * the log block it starts at.
- *
+ * the log block it starts at.
+ *
* If the log is now empty, we need to work out which is the
* next transaction ID we will write, and where it will
* start. */
freed = freed + journal->j_last - journal->j_first;
jbd_debug(1,
- "Cleaning journal tail from %d to %d (offset %lu), "
- "freeing %lu\n",
+ "Cleaning journal tail from %d to %d (offset %u), "
+ "freeing %u\n",
journal->j_tail_sequence, first_tid, blocknr, freed);
journal->j_free += freed;
if (!jh)
return 0;
- last_jh = jh->b_cpprev;
+ last_jh = jh->b_cpprev;
do {
jh = next_jh;
next_jh = jh->b_cpnext;
}
}
/*
- * This function only frees up some memory if possible so we
- * dont have an obligation to finish processing. Bail out if
- * preemption requested:
+ * This function only frees up some memory
+ * if possible so we dont have an obligation
+ * to finish processing. Bail out if preemption
+ * requested:
*/
if (need_resched())
return freed;
int __journal_clean_checkpoint_list(journal_t *journal)
{
transaction_t *transaction, *last_transaction, *next_transaction;
- int ret = 0, released;
+ int ret = 0;
+ int released;
transaction = journal->j_checkpoint_transactions;
if (!transaction)
next_transaction = transaction->t_cpnext;
ret += journal_clean_one_cp_list(transaction->
t_checkpoint_list, &released);
+ /*
+ * This function only frees up some memory if possible so we
+ * dont have an obligation to finish processing. Bail out if
+ * preemption requested:
+ */
if (need_resched())
goto out;
if (released)
return ret;
}
-/*
+/*
* journal_remove_checkpoint: called after a buffer has been committed
* to disk (either by being write-back flushed to disk, or being
* committed to the log).
/*
* There is one special case to worry about: if we have just pulled the
- * buffer off a committing transaction's forget list, then even if the
- * checkpoint list is empty, the transaction obviously cannot be
- * dropped!
+ * buffer off a running or committing transaction's checkpoing list,
+ * then even if the checkpoint list is empty, the transaction obviously
+ * cannot be dropped!
*
- * The locking here around j_committing_transaction is a bit sleazy.
+ * The locking here around t_state is a bit sleazy.
* See the comment at the end of journal_commit_transaction().
*/
- if (transaction == journal->j_committing_transaction) {
- JBUFFER_TRACE(jh, "belongs to committing transaction");
+ if (transaction->t_state != T_FINISHED) {
+ JBUFFER_TRACE(jh, "belongs to running/committing transaction");
goto out;
}
* Called with the journal locked.
* Called with j_list_lock held.
*/
-void __journal_insert_checkpoint(struct journal_head *jh,
+void __journal_insert_checkpoint(struct journal_head *jh,
transaction_t *transaction)
{
JBUFFER_TRACE(jh, "entry");
/*
* We've finished with this transaction structure: adios...
- *
+ *
* The transaction must have no links except for the checkpoint by this
* point.
*
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff