/*
* linux/fs/transaction.c
- *
+ *
* Written by Stephen C. Tweedie <sct@redhat.com>, 1998
*
* Copyright 1998 Red Hat corp --- All Rights Reserved
* option, any later version, incorporated herein by reference.
*
* Generic filesystem transaction handling code; part of the ext2fs
- * journaling system.
+ * journaling system.
*
* This file manages transactions (compound commits managed by the
* journaling code) and handles (individual atomic operations by the
* start_this_handle: Given a handle, deal with any locking or stalling
* needed to make sure that there is enough journal space for the handle
* to begin. Attach the handle to a transaction and set up the
- * transaction's buffer credits.
+ * transaction's buffer credits.
*/
static int start_this_handle(journal_t *journal, handle_t *handle)
if (is_journal_aborted(journal) ||
(journal->j_errno != 0 && !(journal->j_flags & JFS_ACK_ERR))) {
spin_unlock(&journal->j_state_lock);
- ret = -EROFS;
+ ret = -EROFS;
goto out;
}
goto repeat;
}
- /*
+ /*
* The commit code assumes that it can get enough log space
* without forcing a checkpoint. This is *critical* for
* correctness: a checkpoint of a buffer which is also
*
* We must therefore ensure the necessary space in the journal
* *before* starting to dirty potentially checkpointed buffers
- * in the new transaction.
+ * in the new transaction.
*
* The worst part is, any transaction currently committing can
* reduce the free space arbitrarily. Be careful to account for
}
/**
- * handle_t *journal_start() - Obtain a new handle.
+ * handle_t *journal_start() - Obtain a new handle.
* @journal: Journal to start transaction on.
* @nblocks: number of block buffer we might modify
*
* We make sure that the transaction can guarantee at least nblocks of
* modified buffers in the log. We block until the log can guarantee
- * that much space.
+ * that much space.
*
* This function is visible to journal users (like ext3fs), so is not
* called with the journal already locked.
* int journal_extend() - extend buffer credits.
* @handle: handle to 'extend'
* @nblocks: nr blocks to try to extend by.
- *
+ *
* Some transactions, such as large extends and truncates, can be done
* atomically all at once or in several stages. The operation requests
* a credit for a number of buffer modications in advance, but can
- * extend its credit if it needs more.
+ * extend its credit if it needs more.
*
* journal_extend tries to give the running handle more buffer credits.
* It does not guarantee that allocation - this is a best-effort only.
* int journal_restart() - restart a handle .
* @handle: handle to restart
* @nblocks: nr credits requested
- *
+ *
* Restart a handle for a multi-transaction filesystem
* operation.
*
/**
* void journal_unlock_updates (journal_t* journal) - release barrier
* @journal: Journal to release the barrier on.
- *
+ *
* Release a transaction barrier obtained with journal_lock_updates().
*
* Should be called without the journal lock held.
jbd_lock_bh_state(bh);
/* We now hold the buffer lock so it is safe to query the buffer
- * state. Is the buffer dirty?
- *
+ * state. Is the buffer dirty?
+ *
* If so, there are two possibilities. The buffer may be
* non-journaled, and undergoing a quite legitimate writeback.
* Otherwise, it is journaled, and we don't expect dirty buffers
*/
if (jh->b_transaction) {
J_ASSERT_JH(jh,
- jh->b_transaction == transaction ||
+ jh->b_transaction == transaction ||
jh->b_transaction ==
journal->j_committing_transaction);
if (jh->b_next_transaction)
*/
JBUFFER_TRACE(jh, "Unexpected dirty buffer");
jbd_unexpected_dirty_buffer(jh);
- }
+ }
unlock_buffer(bh);
* buffer had better remain locked during the kmalloc,
* but that should be true --- we hold the journal lock
* still and the buffer is already on the BUF_JOURNAL
- * list so won't be flushed.
+ * list so won't be flushed.
*
* Subtle point, though: if this is a get_undo_access,
* then we will be relying on the frozen_data to contain
out:
if (unlikely(frozen_buffer)) /* It's usually NULL */
- kfree(frozen_buffer);
+ jbd_slab_free(frozen_buffer, bh->b_size);
JBUFFER_TRACE(jh, "exit");
return error;
* manually rather than reading off disk), then we need to keep the
* buffer_head locked until it has been completely filled with new
* data. In this case, we should be able to make the assertion that
- * the bh is not already part of an existing transaction.
- *
+ * the bh is not already part of an existing transaction.
+ *
* The buffer should already be locked by the caller by this point.
* There is no lock ranking violation: it was a newly created,
* unlocked buffer beforehand. */
*
* Call this if you create a new bh.
*/
-int journal_get_create_access(handle_t *handle, struct buffer_head *bh)
+int journal_get_create_access(handle_t *handle, struct buffer_head *bh)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
* do not reuse freed space until the deallocation has been committed,
* since if we overwrote that space we would make the delete
* un-rewindable in case of a crash.
- *
+ *
* To deal with that, journal_get_undo_access requests write access to a
* buffer for parts of non-rewindable operations such as delete
* operations on the bitmaps. The journaling code must keep a copy of
* the buffer's contents prior to the undo_access call until such time
* as we know that the buffer has definitely been committed to disk.
- *
+ *
* We never need to know which transaction the committed data is part
* of, buffers touched here are guaranteed to be dirtied later and so
* will be committed to a new transaction in due course, at which point
return err;
}
-/**
+/**
* int journal_dirty_data() - mark a buffer as containing dirty data which
* needs to be flushed before we can commit the
- * current transaction.
+ * current transaction.
* @handle: transaction
* @bh: bufferhead to mark
- *
+ *
* The buffer is placed on the transaction's data list and is marked as
* belonging to the transaction.
*
/*
* What if the buffer is already part of a running transaction?
- *
+ *
* There are two cases:
* 1) It is part of the current running transaction. Refile it,
* just in case we have allocated it as metadata, deallocated
- * it, then reallocated it as data.
+ * it, then reallocated it as data.
* 2) It is part of the previous, still-committing transaction.
* If all we want to do is to guarantee that the buffer will be
* written to disk before this new transaction commits, then
- * being sure that the *previous* transaction has this same
+ * being sure that the *previous* transaction has this same
* property is sufficient for us! Just leave it on its old
* transaction.
*
return 0;
}
-/**
+/**
* int journal_dirty_metadata() - mark a buffer as containing dirty metadata
* @handle: transaction to add buffer to.
- * @bh: buffer to mark
- *
+ * @bh: buffer to mark
+ *
* mark dirty metadata which needs to be journaled as part of the current
* transaction.
*
* The buffer is placed on the transaction's metadata list and is marked
- * as belonging to the transaction.
+ * as belonging to the transaction.
*
- * Returns error number or 0 on success.
+ * Returns error number or 0 on success.
*
* Special care needs to be taken if the buffer already belongs to the
* current committing transaction (in which case we should have frozen
set_buffer_jbddirty(bh);
- /*
+ /*
* Metadata already on the current transaction list doesn't
* need to be filed. Metadata on another transaction's list must
* be committing, and will be refiled once the commit completes:
- * leave it alone for now.
+ * leave it alone for now.
*/
if (jh->b_transaction != transaction) {
JBUFFER_TRACE(jh, "already on other transaction");
return 0;
}
-/*
+/*
* journal_release_buffer: undo a get_write_access without any buffer
* updates, if the update decided in the end that it didn't need access.
*
BUFFER_TRACE(bh, "entry");
}
-/**
+/**
* void journal_forget() - bforget() for potentially-journaled buffers.
* @handle: transaction handle
* @bh: bh to 'forget'
*
* We can only do the bforget if there are no commits pending against the
* buffer. If the buffer is dirty in the current running transaction we
- * can safely unlink it.
+ * can safely unlink it.
*
* bh may not be a journalled buffer at all - it may be a non-JBD
* buffer which came off the hashtable. Check for this.
*
* Decrements bh->b_count by one.
- *
+ *
* Allow this call even if the handle has aborted --- it may be part of
* the caller's cleanup after an abort.
*/
drop_reserve = 1;
- /*
+ /*
* We are no longer going to journal this buffer.
* However, the commit of this transaction is still
* important to the buffer: the delete that we are now
*
* So, if we have a checkpoint on the buffer, we should
* now refile the buffer on our BJ_Forget list so that
- * we know to remove the checkpoint after we commit.
+ * we know to remove the checkpoint after we commit.
*/
if (jh->b_cp_transaction) {
}
}
} else if (jh->b_transaction) {
- J_ASSERT_JH(jh, (jh->b_transaction ==
+ J_ASSERT_JH(jh, (jh->b_transaction ==
journal->j_committing_transaction));
/* However, if the buffer is still owned by a prior
* (committing) transaction, we can't drop it yet... */
/**
* int journal_stop() - complete a transaction
* @handle: tranaction to complete.
- *
+ *
* All done for a particular handle.
*
* There is not much action needed here. We just return any remaining
* filesystem is marked for synchronous update.
*
* journal_stop itself will not usually return an error, but it may
- * do so in unusual circumstances. In particular, expect it to
+ * do so in unusual circumstances. In particular, expect it to
* return -EIO if a journal_abort has been executed since the
* transaction began.
*/
int old_handle_count, err;
pid_t pid;
- J_ASSERT(transaction->t_updates > 0);
J_ASSERT(journal_current_handle() == handle);
if (is_handle_aborted(handle))
err = -EIO;
- else
+ else {
+ J_ASSERT(transaction->t_updates > 0);
err = 0;
+ }
if (--handle->h_ref > 0) {
jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
if (handle->h_sync ||
transaction->t_outstanding_credits >
journal->j_max_transaction_buffers ||
- time_after_eq(jiffies, transaction->t_expires)) {
+ time_after_eq(jiffies, transaction->t_expires)) {
/* Do this even for aborted journals: an abort still
* completes the commit thread, it just doesn't write
* anything to disk. */
/*
* Special case: JFS_SYNC synchronous updates require us
- * to wait for the commit to complete.
+ * to wait for the commit to complete.
*/
if (handle->h_sync && !(current->flags & PF_MEMALLOC))
err = log_wait_commit(journal, tid);
* jbd_lock_bh_state(jh2bh(jh)) is held.
*/
-static inline void
+static inline void
__blist_add_buffer(struct journal_head **list, struct journal_head *jh)
{
if (!*list) {
}
}
-/*
+/*
* Remove a buffer from a transaction list, given the transaction's list
* head pointer.
*
jh->b_tnext->b_tprev = jh->b_tprev;
}
-/*
+/*
* Remove a buffer from the appropriate transaction list.
*
* Note that this function can *change* the value of
}
-/**
+/**
* int journal_try_to_free_buffers() - try to free page buffers.
* @journal: journal for operation
* @page: to try and free
* @unused_gfp_mask: unused
*
- *
+ *
* For all the buffers on this page,
* if they are fully written out ordered data, move them onto BUF_CLEAN
* so try_to_free_buffers() can reap them.
- *
+ *
* This function returns non-zero if we wish try_to_free_buffers()
* to be called. We do this if the page is releasable by try_to_free_buffers().
* We also do it if the page has locked or dirty buffers and the caller wants
* cannot happen because we never reallocate freed data as metadata
* while the data is part of a transaction. Yes?
*/
-int journal_try_to_free_buffers(journal_t *journal,
+int journal_try_to_free_buffers(journal_t *journal,
struct page *page, gfp_t unused_gfp_mask)
{
struct buffer_head *head;
}
/*
- * journal_invalidatepage
+ * journal_invalidatepage
*
* This code is tricky. It has a number of cases to deal with.
*
*
* i_size must be updated on disk before we start calling invalidatepage on the
* data.
- *
+ *
* This is done in ext3 by defining an ext3_setattr method which
* updates i_size before truncate gets going. By maintaining this
* invariant, we can be sure that it is safe to throw away any buffers
* attached to the current transaction: once the transaction commits,
* we know that the data will not be needed.
- *
+ *
* Note however that we can *not* throw away data belonging to the
- * previous, committing transaction!
+ * previous, committing transaction!
*
* Any disk blocks which *are* part of the previous, committing
* transaction (and which therefore cannot be discarded immediately) are
* don't make guarantees about the order in which data hits disk --- in
* particular we don't guarantee that new dirty data is flushed before
* transaction commit --- so it is always safe just to discard data
- * immediately in that mode. --sct
+ * immediately in that mode. --sct
*/
/*
return may_free;
}
-/**
+/**
* void journal_invalidatepage()
- * @journal: journal to use for flush...
+ * @journal: journal to use for flush...
* @page: page to flush
* @offset: length of page to invalidate.
*
*
*/
void journal_invalidatepage(journal_t *journal,
- struct page *page,
+ struct page *page,
unsigned long offset)
{
struct buffer_head *head, *bh, *next;
next = bh->b_this_page;
if (offset <= curr_off) {
- /* This block is wholly outside the truncation point */
+ /* This block is wholly outside the truncation point */
lock_buffer(bh);
may_free &= journal_unmap_buffer(journal, bh);
unlock_buffer(bh);
}
}
-/*
- * File a buffer on the given transaction list.
+/*
+ * File a buffer on the given transaction list.
*/
void __journal_file_buffer(struct journal_head *jh,
transaction_t *transaction, int jlist)
* with __jbd_unexpected_dirty_buffer()'s handling of dirty
* state. */
- if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
+ if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
jlist == BJ_Shadow || jlist == BJ_Forget) {
if (test_clear_buffer_dirty(bh) ||
test_clear_buffer_jbddirty(bh))
jbd_unlock_bh_state(jh2bh(jh));
}
-/*
+/*
* Remove a buffer from its current buffer list in preparation for
* dropping it from its current transaction entirely. If the buffer has
* already started to be used by a subsequent transaction, refile the
* to the caller to remove the journal_head if necessary. For the
* unlocked journal_refile_buffer call, the caller isn't going to be
* doing anything else to the buffer so we need to do the cleanup
- * ourselves to avoid a jh leak.
+ * ourselves to avoid a jh leak.
*
* *** The journal_head may be freed by this call! ***
*/
git.openpandora.org / pandora-kernel.git / blobdiff