Merge tag 'regulator-v3.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni...

[~andy/linux] / fs / jbd / transaction.c

diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index e3e255c0a50968cd41efe9f9b9706290875f47fd..be0c39b66fe082402435673cab806426ba3a165e 100644 (file)
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -2019,16 +2019,20 @@ zap_buffer_unlocked:
  * void journal_invalidatepage() - invalidate a journal page
  * @journal: journal to use for flush
  * @page:    page to flush
- * @offset:  length of page to invalidate.
+ * @offset:  offset of the range to invalidate
+ * @length:  length of the range to invalidate
  *
- * Reap page buffers containing data after offset in page.
+ * Reap page buffers containing data in specified range in page.
  */
 void journal_invalidatepage(journal_t *journal,
                      struct page *page,
-                     unsigned long offset)
+                     unsigned int offset,
+                     unsigned int length)
 {
        struct buffer_head *head, *bh, *next;
+       unsigned int stop = offset + length;
        unsigned int curr_off = 0;
+       int partial_page = (offset || length < PAGE_CACHE_SIZE);
        int may_free = 1;
 
        if (!PageLocked(page))
@@ -2036,6 +2040,8 @@ void journal_invalidatepage(journal_t *journal,
        if (!page_has_buffers(page))
                return;
 
+       BUG_ON(stop > PAGE_CACHE_SIZE || stop < length);
+
        /* We will potentially be playing with lists other than just the
         * data lists (especially for journaled data mode), so be
         * cautious in our locking. */
@@ -2045,11 +2051,14 @@ void journal_invalidatepage(journal_t *journal,
                unsigned int next_off = curr_off + bh->b_size;
                next = bh->b_this_page;
 
+               if (next_off > stop)
+                       return;
+
                if (offset <= curr_off) {
                        /* This block is wholly outside the truncation point */
                        lock_buffer(bh);
                        may_free &= journal_unmap_buffer(journal, bh,
-                                                        offset > 0);
+                                                        partial_page);
                        unlock_buffer(bh);
                }
                curr_off = next_off;
@@ -2057,7 +2066,7 @@ void journal_invalidatepage(journal_t *journal,
 
        } while (bh != head);
 
-       if (!offset) {
+       if (!partial_page) {
                if (may_free && try_to_free_buffers(page))
                        J_ASSERT(!page_has_buffers(page));
        }