goto out;
}
- lock_acquire(&handle->h_lockdep_map, 0, 0, 0, 2, _THIS_IP_);
+ lock_map_acquire(&handle->h_lockdep_map);
out:
return handle;
jh->b_next_transaction == transaction)
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
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);
if (jh->b_transaction == NULL) {
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;
}
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;
}
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.
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;
}
}
spin_unlock(&journal->j_state_lock);
}
- lock_release(&handle->h_lockdep_map, 1, _THIS_IP_);
+ lock_map_release(&handle->h_lockdep_map);
jbd_free_handle(handle);
return err;
return;
}
+/*
+ * journal_try_to_free_buffers() could race with journal_commit_transaction()
+ * The latter might still hold the a count on buffers when inspecting
+ * them on t_syncdata_list or t_locked_list.
+ *
+ * journal_try_to_free_buffers() will call this function to
+ * wait for the current transaction to finish syncing data buffers, before
+ * tryinf to free that buffer.
+ *
+ * Called with journal->j_state_lock held.
+ */
+static void journal_wait_for_transaction_sync_data(journal_t *journal)
+{
+ transaction_t *transaction = NULL;
+ tid_t tid;
+
+ spin_lock(&journal->j_state_lock);
+ transaction = journal->j_committing_transaction;
+
+ if (!transaction) {
+ spin_unlock(&journal->j_state_lock);
+ return;
+ }
+
+ tid = transaction->t_tid;
+ spin_unlock(&journal->j_state_lock);
+ log_wait_commit(journal, tid);
+}
/**
* 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,
* 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)
+ 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);
+
+ /*
+ * There are a number of places where journal_try_to_free_buffers()
+ * could race with journal_commit_transaction(), the later still
+ * holds the reference to the buffers to free while processing them.
+ * try_to_free_buffers() failed to free those buffers. Some of the
+ * caller of releasepage() request page buffers to be dropped, otherwise
+ * treat the fail-to-free as errors (such as generic_file_direct_IO())
+ *
+ * So, if the caller of try_to_release_page() wants the synchronous
+ * behaviour(i.e make sure buffers are dropped upon return),
+ * let's wait for the current transaction to finish flush of
+ * dirty data buffers, then try to free those buffers again,
+ * with the journal locked.
+ */
+ if (ret == 0 && (gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS)) {
+ journal_wait_for_transaction_sync_data(journal);
+ ret = try_to_free_buffers(page);
+ }
+
busy:
return ret;
}
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)
projects / linux-2.6-omap-h63xx.git / blobdiff