/*
- * linux/fs/transaction.c
- *
+ * linux/fs/jbd/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
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/timer.h>
-#include <linux/smp_lock.h>
#include <linux/mm.h>
#include <linux/highmem.h>
+#include <linux/hrtimer.h>
+
+static void __journal_temp_unlink_buffer(struct journal_head *jh);
/*
* get_transaction: obtain a new transaction_t object.
{
transaction->t_journal = journal;
transaction->t_state = T_RUNNING;
+ transaction->t_start_time = ktime_get();
transaction->t_tid = journal->j_transaction_sequence++;
transaction->t_expires = jiffies + journal->j_commit_interval;
spin_lock_init(&transaction->t_handle_lock);
/* Set up the commit timer for the new transaction. */
- journal->j_commit_timer.expires = transaction->t_expires;
+ journal->j_commit_timer.expires =
+ round_jiffies_up(transaction->t_expires);
add_timer(&journal->j_commit_timer);
J_ASSERT(journal->j_running_transaction == NULL);
* 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)
alloc_transaction:
if (!journal->j_running_transaction) {
- new_transaction = jbd_kmalloc(sizeof(*new_transaction),
- GFP_NOFS);
+ new_transaction = kzalloc(sizeof(*new_transaction),
+ GFP_NOFS|__GFP_NOFAIL);
if (!new_transaction) {
ret = -ENOMEM;
goto out;
}
- memset(new_transaction, 0, sizeof(*new_transaction));
}
jbd_debug(3, "New handle %p going live.\n", 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
__log_space_left(journal));
spin_unlock(&transaction->t_handle_lock);
spin_unlock(&journal->j_state_lock);
+
+ lock_map_acquire(&handle->h_lockdep_map);
out:
- kfree(new_transaction);
+ if (unlikely(new_transaction)) /* It's usually NULL */
+ kfree(new_transaction);
return ret;
}
+static struct lock_class_key jbd_handle_key;
+
/* Allocate a new handle. This should probably be in a slab... */
static handle_t *new_handle(int nblocks)
{
handle->h_buffer_credits = nblocks;
handle->h_ref = 1;
+ lockdep_init_map(&handle->h_lockdep_map, "jbd_handle", &jbd_handle_key, 0);
+
return handle;
}
/**
- * 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.
jbd_free_handle(handle);
current->journal_info = NULL;
handle = ERR_PTR(err);
+ goto out;
}
+out:
return handle;
}
* 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 .
+ * int journal_restart() - restart a handle.
* @handle: handle to restart
* @nblocks: nr credits requested
- *
+ *
* Restart a handle for a multi-transaction filesystem
* operation.
*
__log_start_commit(journal, transaction->t_tid);
spin_unlock(&journal->j_state_lock);
+ lock_map_release(&handle->h_lockdep_map);
handle->h_buffer_credits = nblocks;
ret = start_this_handle(journal, handle);
return ret;
/**
* 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.
wake_up(&journal->j_wait_transaction_locked);
}
-/*
- * Report any unexpected dirty buffers which turn up. Normally those
- * indicate an error, but they can occur if the user is running (say)
- * tune2fs to modify the live filesystem, so we need the option of
- * continuing as gracefully as possible. #
- *
- * The caller should already hold the journal lock and
- * j_list_lock spinlock: most callers will need those anyway
- * in order to probe the buffer's journaling state safely.
- */
-static void jbd_unexpected_dirty_buffer(struct journal_head *jh)
+static void warn_dirty_buffer(struct buffer_head *bh)
{
- int jlist;
-
- /* If this buffer is one which might reasonably be dirty
- * --- ie. data, or not part of this journal --- then
- * we're OK to leave it alone, but otherwise we need to
- * move the dirty bit to the journal's own internal
- * JBDDirty bit. */
- jlist = jh->b_jlist;
+ char b[BDEVNAME_SIZE];
- if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
- jlist == BJ_Shadow || jlist == BJ_Forget) {
- struct buffer_head *bh = jh2bh(jh);
-
- if (test_clear_buffer_dirty(bh))
- set_buffer_jbddirty(bh);
- }
+ printk(KERN_WARNING
+ "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). "
+ "There's a risk of filesystem corruption in case of system "
+ "crash.\n",
+ bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
}
/*
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)
J_ASSERT_JH(jh, jh->b_next_transaction ==
transaction);
+ warn_dirty_buffer(bh);
}
/*
* In any case we need to clean the dirty flag and we must
* do it under the buffer lock to be sure we don't race
* with running write-out.
*/
- JBUFFER_TRACE(jh, "Unexpected dirty buffer");
- jbd_unexpected_dirty_buffer(jh);
- }
+ JBUFFER_TRACE(jh, "Journalling dirty buffer");
+ clear_buffer_dirty(bh);
+ set_buffer_jbddirty(bh);
+ }
unlock_buffer(bh);
goto done;
/*
+ * this is the first time this transaction is touching this buffer,
+ * reset the modified flag
+ */
+ jh->b_modified = 0;
+
+ /*
* If there is already a copy-out version of this buffer, then we don't
* need to make another one
*/
* 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
if (!frozen_buffer) {
JBUFFER_TRACE(jh, "allocate memory for buffer");
jbd_unlock_bh_state(bh);
- frozen_buffer = jbd_kmalloc(jh2bh(jh)->b_size,
- GFP_NOFS);
+ frozen_buffer =
+ jbd_alloc(jh2bh(jh)->b_size,
+ GFP_NOFS);
if (!frozen_buffer) {
printk(KERN_EMERG
"%s: OOM for frozen_buffer\n",
- __FUNCTION__);
+ __func__);
JBUFFER_TRACE(jh, "oom!");
error = -ENOMEM;
jbd_lock_bh_state(bh);
journal_cancel_revoke(handle, jh);
out:
- kfree(frozen_buffer);
+ if (unlikely(frozen_buffer)) /* It's usually NULL */
+ jbd_free(frozen_buffer, bh->b_size);
JBUFFER_TRACE(jh, "exit");
return error;
* int journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update.
* @handle: transaction to add buffer modifications to
* @bh: bh to be used for metadata writes
- * @credits: variable that will receive credits for the buffer
*
* Returns an error code or 0 on success.
*
* 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;
J_ASSERT_JH(jh, buffer_locked(jh2bh(jh)));
if (jh->b_transaction == NULL) {
+ /*
+ * Previous journal_forget() could have left the buffer
+ * with jbddirty bit set because it was being committed. When
+ * the commit finished, we've filed the buffer for
+ * checkpointing and marked it dirty. Now we are reallocating
+ * the buffer so the transaction freeing it must have
+ * committed and so it's safe to clear the dirty bit.
+ */
+ clear_buffer_dirty(jh2bh(jh));
jh->b_transaction = transaction;
+
+ /* first access by this transaction */
+ jh->b_modified = 0;
+
JBUFFER_TRACE(jh, "file as BJ_Reserved");
__journal_file_buffer(jh, transaction, BJ_Reserved);
} else if (jh->b_transaction == journal->j_committing_transaction) {
+ /* first access by this transaction */
+ jh->b_modified = 0;
+
JBUFFER_TRACE(jh, "set next transaction");
jh->b_next_transaction = transaction;
}
}
/**
- * int journal_get_undo_access() - Notify intent to modify metadata with
- * non-rewindable consequences
+ * int journal_get_undo_access() - Notify intent to modify metadata with non-rewindable consequences
* @handle: transaction
* @bh: buffer to undo
- * @credits: store the number of taken credits here (if not NULL)
*
* Sometimes there is a need to distinguish between metadata which has
* been committed to disk and that which has not. The ext3fs code uses
* 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
repeat:
if (!jh->b_committed_data) {
- committed_data = jbd_kmalloc(jh2bh(jh)->b_size, GFP_NOFS);
+ committed_data = jbd_alloc(jh2bh(jh)->b_size, GFP_NOFS);
if (!committed_data) {
printk(KERN_EMERG "%s: No memory for committed data\n",
- __FUNCTION__);
+ __func__);
err = -ENOMEM;
goto out;
}
jbd_unlock_bh_state(bh);
out:
journal_put_journal_head(jh);
- kfree(committed_data);
+ if (unlikely(committed_data))
+ jbd_free(committed_data, bh->b_size);
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.
+/**
+ * int journal_dirty_data() - mark a buffer as containing dirty data to be flushed
* @handle: transaction
* @bh: bufferhead to mark
- *
+ *
+ * Description:
+ * Mark a buffer as containing dirty data which needs to be flushed before
+ * we can commit the current transaction.
+ *
* The buffer is placed on the transaction's data list and is marked as
* belonging to the transaction.
*
journal_t *journal = handle->h_transaction->t_journal;
int need_brelse = 0;
struct journal_head *jh;
+ int ret = 0;
if (is_handle_aborted(handle))
- return 0;
+ return ret;
jh = journal_add_journal_head(bh);
JBUFFER_TRACE(jh, "entry");
/*
* 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.
*
*/
jbd_lock_bh_state(bh);
spin_lock(&journal->j_list_lock);
+
+ /* Now that we have bh_state locked, are we really still mapped? */
+ if (!buffer_mapped(bh)) {
+ JBUFFER_TRACE(jh, "unmapped buffer, bailing out");
+ goto no_journal;
+ }
+
if (jh->b_transaction) {
JBUFFER_TRACE(jh, "has transaction");
if (jh->b_transaction != handle->h_transaction) {
sync_dirty_buffer(bh);
jbd_lock_bh_state(bh);
spin_lock(&journal->j_list_lock);
+ /* Since we dropped the lock... */
+ if (!buffer_mapped(bh)) {
+ JBUFFER_TRACE(jh, "buffer got unmapped");
+ goto no_journal;
+ }
/* The buffer may become locked again at any
time if it is redirtied */
}
- /* journal_clean_data_list() may have got there first */
+ /*
+ * We cannot remove the buffer with io error from the
+ * committing transaction, because otherwise it would
+ * miss the error and the commit would not abort.
+ */
+ if (unlikely(!buffer_uptodate(bh))) {
+ ret = -EIO;
+ goto no_journal;
+ }
+
if (jh->b_transaction != NULL) {
JBUFFER_TRACE(jh, "unfile from commit");
__journal_temp_unlink_buffer(jh);
}
JBUFFER_TRACE(jh, "exit");
journal_put_journal_head(jh);
- return 0;
+ return ret;
}
-/**
- * int journal_dirty_metadata() - mark a buffer as containing dirty metadata
+/**
+ * int journal_dirty_metadata() - mark a buffer as containing dirty metadata
* @handle: transaction to add buffer to.
- * @bh: buffer to mark
- *
- * mark dirty metadata which needs to be journaled as part of the current
+ * @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");
}
/* That test should have eliminated the following case: */
- J_ASSERT_JH(jh, jh->b_frozen_data == 0);
+ J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
JBUFFER_TRACE(jh, "file as BJ_Metadata");
spin_lock(&journal->j_list_lock);
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.
*/
struct journal_head *jh;
int drop_reserve = 0;
int err = 0;
+ int was_modified = 0;
BUFFER_TRACE(bh, "entry");
goto not_jbd;
}
+ /* keep track of wether or not this transaction modified us */
+ was_modified = jh->b_modified;
+
/*
* The buffer's going from the transaction, we must drop
* all references -bzzz
JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
- drop_reserve = 1;
+ /*
+ * we only want to drop a reference if this transaction
+ * modified the buffer
+ */
+ if (was_modified)
+ 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... */
if (jh->b_next_transaction) {
J_ASSERT(jh->b_next_transaction == transaction);
jh->b_next_transaction = NULL;
- drop_reserve = 1;
+
+ /*
+ * only drop a reference if this transaction modified
+ * the buffer
+ */
+ if (was_modified)
+ drop_reserve = 1;
}
}
/**
* 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.
*/
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
- int old_handle_count, err;
+ int 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,
* on IO anyway. Speeds up many-threaded, many-dir operations
* by 30x or more...
*
+ * We try and optimize the sleep time against what the underlying disk
+ * can do, instead of having a static sleep time. This is usefull for
+ * the case where our storage is so fast that it is more optimal to go
+ * ahead and force a flush and wait for the transaction to be committed
+ * than it is to wait for an arbitrary amount of time for new writers to
+ * join the transaction. We acheive this by measuring how long it takes
+ * to commit a transaction, and compare it with how long this
+ * transaction has been running, and if run time < commit time then we
+ * sleep for the delta and commit. This greatly helps super fast disks
+ * that would see slowdowns as more threads started doing fsyncs.
+ *
* But don't do this if this process was the most recent one to
* perform a synchronous write. We do this to detect the case where a
* single process is doing a stream of sync writes. No point in waiting
*/
pid = current->pid;
if (handle->h_sync && journal->j_last_sync_writer != pid) {
+ u64 commit_time, trans_time;
+
journal->j_last_sync_writer = pid;
- do {
- old_handle_count = transaction->t_handle_count;
- schedule_timeout_uninterruptible(1);
- } while (old_handle_count != transaction->t_handle_count);
+
+ spin_lock(&journal->j_state_lock);
+ commit_time = journal->j_average_commit_time;
+ spin_unlock(&journal->j_state_lock);
+
+ trans_time = ktime_to_ns(ktime_sub(ktime_get(),
+ transaction->t_start_time));
+
+ commit_time = min_t(u64, commit_time,
+ 1000*jiffies_to_usecs(1));
+
+ if (trans_time < commit_time) {
+ ktime_t expires = ktime_add_ns(ktime_get(),
+ commit_time);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
+ }
}
+ if (handle->h_sync)
+ transaction->t_synchronous_commit = 1;
current->journal_info = NULL;
spin_lock(&journal->j_state_lock);
spin_lock(&transaction->t_handle_lock);
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);
spin_unlock(&journal->j_state_lock);
}
+ lock_map_release(&handle->h_lockdep_map);
+
jbd_free_handle(handle);
return err;
}
-/**int journal_force_commit() - force any uncommitted transactions
+/**
+ * int journal_force_commit() - force any uncommitted transactions
* @journal: journal to force
*
* For synchronous operations: force any uncommitted transactions
* 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
*
* Called under j_list_lock. The journal may not be locked.
*/
-void __journal_temp_unlink_buffer(struct journal_head *jh)
+static void __journal_temp_unlink_buffer(struct journal_head *jh)
{
struct journal_head **list = NULL;
transaction_t *transaction;
J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
if (jh->b_jlist != BJ_None)
- J_ASSERT_JH(jh, transaction != 0);
+ J_ASSERT_JH(jh, transaction != NULL);
switch (jh->b_jlist) {
case BJ_None:
if (buffer_locked(bh) || buffer_dirty(bh))
goto out;
- if (jh->b_next_transaction != 0)
+ if (jh->b_next_transaction != NULL)
goto out;
spin_lock(&journal->j_list_lock);
- if (jh->b_transaction != 0 && jh->b_cp_transaction == 0) {
+ if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) {
if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) {
/* A written-back ordered data buffer */
JBUFFER_TRACE(jh, "release data");
journal_remove_journal_head(bh);
__brelse(bh);
}
- } else if (jh->b_cp_transaction != 0 && jh->b_transaction == 0) {
+ } else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
/* written-back checkpointed metadata buffer */
if (jh->b_jlist == BJ_None) {
JBUFFER_TRACE(jh, "remove from checkpoint list");
return;
}
-
-/**
+/**
* int journal_try_to_free_buffers() - try to free page buffers.
* @journal: journal for operation
* @page: to try and free
- * @unused_gfp_mask: unused
+ * @gfp_mask: we use the mask to detect how hard should we try to release
+ * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
+ * release the buffers.
+ *
*
- *
* 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
* journal_try_to_free_buffer() is changing its state. But that
* cannot happen because we never reallocate freed data as metadata
* while the data is part of a transaction. Yes?
+ *
+ * Return 0 on failure, 1 on success
*/
-int journal_try_to_free_buffers(journal_t *journal,
- struct page *page, gfp_t unused_gfp_mask)
+int journal_try_to_free_buffers(journal_t *journal,
+ struct page *page, gfp_t gfp_mask)
{
struct buffer_head *head;
struct buffer_head *bh;
if (buffer_jbd(bh))
goto busy;
} while ((bh = bh->b_this_page) != head);
+
ret = try_to_free_buffers(page);
+
busy:
return ret;
}
if (jh->b_cp_transaction) {
JBUFFER_TRACE(jh, "on running+cp transaction");
+ /*
+ * We don't want to write the buffer anymore, clear the
+ * bit so that we don't confuse checks in
+ * __journal_file_buffer
+ */
+ clear_buffer_dirty(bh);
__journal_file_buffer(jh, transaction, BJ_Forget);
- clear_buffer_jbddirty(bh);
may_free = 0;
} else {
JBUFFER_TRACE(jh, "on running transaction");
}
/*
- * 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
*/
/*
}
}
} else if (transaction == journal->j_committing_transaction) {
+ JBUFFER_TRACE(jh, "on committing transaction");
if (jh->b_jlist == BJ_Locked) {
/*
* The buffer is on the committing transaction's locked
* can remove it's next_transaction pointer from the
* running transaction if that is set, but nothing
* else. */
- JBUFFER_TRACE(jh, "on committing transaction");
set_buffer_freed(bh);
if (jh->b_next_transaction) {
J_ASSERT(jh->b_next_transaction ==
* i_size already for this truncate so recovery will not
* expose the disk blocks we are discarding here.) */
J_ASSERT_JH(jh, transaction == journal->j_running_transaction);
+ JBUFFER_TRACE(jh, "on running transaction");
may_free = __dispose_buffer(jh, transaction);
}
return may_free;
}
-/**
- * void journal_invalidatepage()
- * @journal: journal to use for flush...
+/**
+ * void journal_invalidatepage() - invalidate a journal page
+ * @journal: journal to use for flush
* @page: page to flush
* @offset: length of page to invalidate.
*
* Reap page buffers containing data after offset in page.
- *
*/
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)
J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
J_ASSERT_JH(jh, jh->b_transaction == transaction ||
- jh->b_transaction == 0);
+ jh->b_transaction == NULL);
if (jh->b_transaction && jh->b_jlist == jlist)
return;
- /* The following list of buffer states needs to be consistent
- * 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) {
+ /*
+ * For metadata buffers, we track dirty bit in buffer_jbddirty
+ * instead of buffer_dirty. We should not see a dirty bit set
+ * here because we clear it in do_get_write_access but e.g.
+ * tune2fs can modify the sb and set the dirty bit at any time
+ * so we try to gracefully handle that.
+ */
+ if (buffer_dirty(bh))
+ warn_dirty_buffer(bh);
if (test_clear_buffer_dirty(bh) ||
test_clear_buffer_jbddirty(bh))
was_dirty = 1;
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
jh->b_transaction = jh->b_next_transaction;
jh->b_next_transaction = NULL;
__journal_file_buffer(jh, jh->b_transaction,
- was_dirty ? BJ_Metadata : BJ_Reserved);
+ jh->b_modified ? BJ_Metadata : BJ_Reserved);
J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
if (was_dirty)
* 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://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff