#include <linux/module.h>
static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh);
+static void __jbd2_journal_unfile_buffer(struct journal_head *jh);
/*
* jbd2_get_transaction: obtain a new transaction_t object.
if (!jh->b_transaction) {
JBUFFER_TRACE(jh, "no transaction");
J_ASSERT_JH(jh, !jh->b_next_transaction);
- jh->b_transaction = transaction;
JBUFFER_TRACE(jh, "file as BJ_Reserved");
spin_lock(&journal->j_list_lock);
__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
* int jbd2_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.
*
* 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;
* 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
__jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
} else {
__jbd2_journal_unfile_buffer(jh);
- jbd2_journal_remove_journal_head(bh);
- __brelse(bh);
if (!buffer_jbd(bh)) {
spin_unlock(&journal->j_list_lock);
jbd_unlock_bh_state(bh);
mark_buffer_dirty(bh); /* Expose it to the VM */
}
-void __jbd2_journal_unfile_buffer(struct journal_head *jh)
+/*
+ * Remove buffer from all transactions.
+ *
+ * Called with bh_state lock and j_list_lock
+ *
+ * jh and bh may be already freed when this function returns.
+ */
+static void __jbd2_journal_unfile_buffer(struct journal_head *jh)
{
__jbd2_journal_temp_unlink_buffer(jh);
jh->b_transaction = NULL;
+ jbd2_journal_put_journal_head(jh);
}
void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh)
{
- jbd_lock_bh_state(jh2bh(jh));
+ struct buffer_head *bh = jh2bh(jh);
+
+ /* Get reference so that buffer cannot be freed before we unlock it */
+ get_bh(bh);
+ jbd_lock_bh_state(bh);
spin_lock(&journal->j_list_lock);
__jbd2_journal_unfile_buffer(jh);
spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(jh2bh(jh));
+ jbd_unlock_bh_state(bh);
+ __brelse(bh);
}
/*
if (jh->b_jlist == BJ_None) {
JBUFFER_TRACE(jh, "remove from checkpoint list");
__jbd2_journal_remove_checkpoint(jh);
- jbd2_journal_remove_journal_head(bh);
- __brelse(bh);
}
}
spin_unlock(&journal->j_list_lock);
/*
* We take our own ref against the journal_head here to avoid
* having to add tons of locking around each instance of
- * jbd2_journal_remove_journal_head() and
* jbd2_journal_put_journal_head().
*/
jh = jbd2_journal_grab_journal_head(bh);
int may_free = 1;
struct buffer_head *bh = jh2bh(jh);
- __jbd2_journal_unfile_buffer(jh);
-
if (jh->b_cp_transaction) {
JBUFFER_TRACE(jh, "on running+cp transaction");
+ __jbd2_journal_temp_unlink_buffer(jh);
/*
* We don't want to write the buffer anymore, clear the
* bit so that we don't confuse checks in
may_free = 0;
} else {
JBUFFER_TRACE(jh, "on running transaction");
- jbd2_journal_remove_journal_head(bh);
- __brelse(bh);
+ __jbd2_journal_unfile_buffer(jh);
}
return may_free;
}
if (jh->b_transaction)
__jbd2_journal_temp_unlink_buffer(jh);
+ else
+ jbd2_journal_grab_journal_head(bh);
jh->b_transaction = transaction;
switch (jlist) {
* already started to be used by a subsequent transaction, refile the
* buffer on that transaction's metadata list.
*
- * Called under journal->j_list_lock
- *
+ * Called under j_list_lock
* Called under jbd_lock_bh_state(jh2bh(jh))
+ *
+ * jh and bh may be already free when this function returns
*/
void __jbd2_journal_refile_buffer(struct journal_head *jh)
{
was_dirty = test_clear_buffer_jbddirty(bh);
__jbd2_journal_temp_unlink_buffer(jh);
+ /*
+ * We set b_transaction here because b_next_transaction will inherit
+ * our jh reference and thus __jbd2_journal_file_buffer() must not
+ * take a new one.
+ */
jh->b_transaction = jh->b_next_transaction;
jh->b_next_transaction = NULL;
if (buffer_freed(bh))
}
/*
- * For the unlocked version of this call, also make sure that any
- * hanging journal_head is cleaned up if necessary.
- *
- * __jbd2_journal_refile_buffer is usually called as part of a single locked
- * operation on a buffer_head, in which the caller is probably going to
- * be hooking the journal_head onto other lists. In that case it is up
- * to the caller to remove the journal_head if necessary. For the
- * unlocked jbd2_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.
- *
- * *** The journal_head may be freed by this call! ***
+ * __jbd2_journal_refile_buffer() with necessary locking added. We take our
+ * bh reference so that we can safely unlock bh.
+ *
+ * The jh and bh may be freed by this call.
*/
void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh)
{
struct buffer_head *bh = jh2bh(jh);
+ /* Get reference so that buffer cannot be freed before we unlock it */
+ get_bh(bh);
jbd_lock_bh_state(bh);
spin_lock(&journal->j_list_lock);
-
__jbd2_journal_refile_buffer(jh);
jbd_unlock_bh_state(bh);
- jbd2_journal_remove_journal_head(bh);
-
spin_unlock(&journal->j_list_lock);
__brelse(bh);
}
git.openpandora.org / pandora-kernel.git / blobdiff