Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bug fixes from Ted Ts'o:
 "Various bug fixes for ext4.  Perhaps the most serious bug fixed is one
  which could cause file system corruptions when performing file punch
  operations."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: avoid hang when mounting non-journal filesystems with orphan list
  ext4: lock i_mutex when truncating orphan inodes
  ext4: do not try to write superblock on ro remount w/o journal
  ext4: include journal blocks in df overhead calcs
  ext4: remove unaligned AIO warning printk
  ext4: fix an incorrect comment about i_mutex
  ext4: fix deadlock in journal_unmap_buffer()
  ext4: split off ext4_journalled_invalidatepage()
  jbd2: fix assertion failure in jbd2_journal_flush()
  ext4: check dioread_nolock on remount
  ext4: fix extent tree corruption caused by hole punch

1 files changed, 16 insertions, 14 deletions

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 42f6615af0ac..df9f29760efa 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;
                 }
@@ -1839,7 +1840,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh,
 
         BUFFER_TRACE(bh, "entry");
 
-retry:
         /*
          * It is safe to proceed here without the j_list_lock because the
          * buffers cannot be stolen by try_to_free_buffers as long as we are
@@ -1934,14 +1934,11 @@ retry:
                  * for commit and try again.
                  */
                 if (partial_page) {
-                        tid_t tid = journal->j_committing_transaction->t_tid;
-
                         jbd2_journal_put_journal_head(jh);
                         spin_unlock(&journal->j_list_lock);
                         jbd_unlock_bh_state(bh);
                         write_unlock(&journal->j_state_lock);
-                        jbd2_log_wait_commit(journal, tid);
-                        goto retry;
+                        return -EBUSY;
                 }
                 /*
                  * OK, buffer won't be reachable after truncate. We just set
@@ -2002,21 +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
@@ -2030,9 +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,
-                                                         offset > 0);
+                        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;
@@ -2043,6 +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;
 }
 
 /*