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-rw-r--r--fs/jbd2/transaction.c94
1 files changed, 55 insertions, 39 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index fb1ab9533b6..df9f29760ef 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -209,7 +209,8 @@ repeat:
if (!new_transaction)
goto alloc_transaction;
write_lock(&journal->j_state_lock);
- if (!journal->j_running_transaction) {
+ if (!journal->j_running_transaction &&
+ !journal->j_barrier_count) {
jbd2_get_transaction(journal, new_transaction);
new_transaction = NULL;
}
@@ -1207,17 +1208,6 @@ out:
return ret;
}
-/*
- * jbd2_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.
- *
- */
-void
-jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh)
-{
- BUFFER_TRACE(bh, "entry");
-}
-
/**
* void jbd2_journal_forget() - bforget() for potentially-journaled buffers.
* @handle: transaction handle
@@ -1261,7 +1251,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
goto not_jbd;
}
- /* keep track of wether or not this transaction modified us */
+ /* keep track of whether or not this transaction modified us */
was_modified = jh->b_modified;
/*
@@ -1841,12 +1831,12 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction)
* We're outside-transaction here. Either or both of j_running_transaction
* and j_committing_transaction may be NULL.
*/
-static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
+static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh,
+ int partial_page)
{
transaction_t *transaction;
struct journal_head *jh;
int may_free = 1;
- int ret;
BUFFER_TRACE(bh, "entry");
@@ -1878,10 +1868,18 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
* clear the buffer dirty bit at latest at the moment when the
* transaction marking the buffer as freed in the filesystem
* structures is committed because from that moment on the
- * buffer can be reallocated and used by a different page.
+ * block can be reallocated and used by a different page.
* Since the block hasn't been freed yet but the inode has
* already been added to orphan list, it is safe for us to add
* the buffer to BJ_Forget list of the newest transaction.
+ *
+ * Also we have to clear buffer_mapped flag of a truncated buffer
+ * because the buffer_head may be attached to the page straddling
+ * i_size (can happen only when blocksize < pagesize) and thus the
+ * buffer_head can be reused when the file is extended again. So we end
+ * up keeping around invalidated buffers attached to transactions'
+ * BJ_Forget list just to stop checkpointing code from cleaning up
+ * the transaction this buffer was modified in.
*/
transaction = jh->b_transaction;
if (transaction == NULL) {
@@ -1908,13 +1906,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
* committed, the buffer won't be needed any
* longer. */
JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget");
- ret = __dispose_buffer(jh,
+ may_free = __dispose_buffer(jh,
journal->j_running_transaction);
- jbd2_journal_put_journal_head(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- write_unlock(&journal->j_state_lock);
- return ret;
+ goto zap_buffer;
} else {
/* There is no currently-running transaction. So the
* orphan record which we wrote for this file must have
@@ -1922,13 +1916,9 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
* the committing transaction, if it exists. */
if (journal->j_committing_transaction) {
JBUFFER_TRACE(jh, "give to committing trans");
- ret = __dispose_buffer(jh,
+ may_free = __dispose_buffer(jh,
journal->j_committing_transaction);
- jbd2_journal_put_journal_head(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- write_unlock(&journal->j_state_lock);
- return ret;
+ goto zap_buffer;
} else {
/* The orphan record's transaction has
* committed. We can cleanse this buffer */
@@ -1940,10 +1930,21 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
JBUFFER_TRACE(jh, "on committing transaction");
/*
* The buffer is committing, we simply cannot touch
- * it. So we just set j_next_transaction to the
- * running transaction (if there is one) and mark
- * buffer as freed so that commit code knows it should
- * clear dirty bits when it is done with the buffer.
+ * it. If the page is straddling i_size we have to wait
+ * for commit and try again.
+ */
+ if (partial_page) {
+ jbd2_journal_put_journal_head(jh);
+ spin_unlock(&journal->j_list_lock);
+ jbd_unlock_bh_state(bh);
+ write_unlock(&journal->j_state_lock);
+ return -EBUSY;
+ }
+ /*
+ * OK, buffer won't be reachable after truncate. We just set
+ * j_next_transaction to the running transaction (if there is
+ * one) and mark buffer as freed so that commit code knows it
+ * should clear dirty bits when it is done with the buffer.
*/
set_buffer_freed(bh);
if (journal->j_running_transaction && buffer_jbddirty(bh))
@@ -1966,6 +1967,15 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
}
zap_buffer:
+ /*
+ * This is tricky. Although the buffer is truncated, it may be reused
+ * if blocksize < pagesize and it is attached to the page straddling
+ * EOF. Since the buffer might have been added to BJ_Forget list of the
+ * running transaction, journal_get_write_access() won't clear
+ * b_modified and credit accounting gets confused. So clear b_modified
+ * here.
+ */
+ jh->b_modified = 0;
jbd2_journal_put_journal_head(jh);
zap_buffer_no_jh:
spin_unlock(&journal->j_list_lock);
@@ -1989,21 +1999,23 @@ zap_buffer_unlocked:
* @page: page to flush
* @offset: length of page to invalidate.
*
- * Reap page buffers containing data after offset in page.
- *
+ * Reap page buffers containing data after offset in page. Can return -EBUSY
+ * if buffers are part of the committing transaction and the page is straddling
+ * i_size. Caller then has to wait for current commit and try again.
*/
-void jbd2_journal_invalidatepage(journal_t *journal,
- struct page *page,
- unsigned long offset)
+int jbd2_journal_invalidatepage(journal_t *journal,
+ struct page *page,
+ unsigned long offset)
{
struct buffer_head *head, *bh, *next;
unsigned int curr_off = 0;
int may_free = 1;
+ int ret = 0;
if (!PageLocked(page))
BUG();
if (!page_has_buffers(page))
- return;
+ return 0;
/* We will potentially be playing with lists other than just the
* data lists (especially for journaled data mode), so be
@@ -2017,8 +2029,11 @@ void jbd2_journal_invalidatepage(journal_t *journal,
if (offset <= curr_off) {
/* This block is wholly outside the truncation point */
lock_buffer(bh);
- may_free &= journal_unmap_buffer(journal, bh);
+ ret = journal_unmap_buffer(journal, bh, offset > 0);
unlock_buffer(bh);
+ if (ret < 0)
+ return ret;
+ may_free &= ret;
}
curr_off = next_off;
bh = next;
@@ -2029,6 +2044,7 @@ void jbd2_journal_invalidatepage(journal_t *journal,
if (may_free && try_to_free_buffers(page))
J_ASSERT(!page_has_buffers(page));
}
+ return 0;
}
/*