Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

[cascardo/linux.git] / fs / jbd / transaction.c

diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 73242ba..c03ac11 100644 (file)
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -489,34 +489,15 @@ void journal_unlock_updates (journal_t *journal)
        wake_up(&journal->j_wait_transaction_locked);
 }
 
-/*
- * Report any unexpected dirty buffers which turn up.  Normally those
- * indicate an error, but they can occur if the user is running (say)
- * tune2fs to modify the live filesystem, so we need the option of
- * continuing as gracefully as possible.  #
- *
- * The caller should already hold the journal lock and
- * j_list_lock spinlock: most callers will need those anyway
- * in order to probe the buffer's journaling state safely.
- */
-static void jbd_unexpected_dirty_buffer(struct journal_head *jh)
+static void warn_dirty_buffer(struct buffer_head *bh)
 {
-       int jlist;
-
-       /* If this buffer is one which might reasonably be dirty
-        * --- ie. data, or not part of this journal --- then
-        * we're OK to leave it alone, but otherwise we need to
-        * move the dirty bit to the journal's own internal
-        * JBDDirty bit. */
-       jlist = jh->b_jlist;
+       char b[BDEVNAME_SIZE];
 
-       if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
-           jlist == BJ_Shadow || jlist == BJ_Forget) {
-               struct buffer_head *bh = jh2bh(jh);
-
-               if (test_clear_buffer_dirty(bh))
-                       set_buffer_jbddirty(bh);
-       }
+       printk(KERN_WARNING
+              "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). "
+              "There's a risk of filesystem corruption in case of system "
+              "crash.\n",
+              bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
 }
 
 /*
@@ -583,14 +564,16 @@ repeat:
                        if (jh->b_next_transaction)
                                J_ASSERT_JH(jh, jh->b_next_transaction ==
                                                        transaction);
+                       warn_dirty_buffer(bh);
                }
                /*
                 * In any case we need to clean the dirty flag and we must
                 * do it under the buffer lock to be sure we don't race
                 * with running write-out.
                 */
-               JBUFFER_TRACE(jh, "Unexpected dirty buffer");
-               jbd_unexpected_dirty_buffer(jh);
+               JBUFFER_TRACE(jh, "Journalling dirty buffer");
+               clear_buffer_dirty(bh);
+               set_buffer_jbddirty(bh);
        }
 
        unlock_buffer(bh);
@@ -826,6 +809,15 @@ int journal_get_create_access(handle_t *handle, struct buffer_head *bh)
        J_ASSERT_JH(jh, buffer_locked(jh2bh(jh)));
 
        if (jh->b_transaction == NULL) {
+               /*
+                * Previous journal_forget() could have left the buffer
+                * with jbddirty bit set because it was being committed. When
+                * the commit finished, we've filed the buffer for
+                * checkpointing and marked it dirty. Now we are reallocating
+                * the buffer so the transaction freeing it must have
+                * 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 */
@@ -1782,8 +1774,13 @@ static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction)
 
        if (jh->b_cp_transaction) {
                JBUFFER_TRACE(jh, "on running+cp transaction");
+               /*
+                * We don't want to write the buffer anymore, clear the
+                * bit so that we don't confuse checks in
+                * __journal_file_buffer
+                */
+               clear_buffer_dirty(bh);
                __journal_file_buffer(jh, transaction, BJ_Forget);
-               clear_buffer_jbddirty(bh);
                may_free = 0;
        } else {
                JBUFFER_TRACE(jh, "on running transaction");
@@ -2041,12 +2038,17 @@ void __journal_file_buffer(struct journal_head *jh,
        if (jh->b_transaction && jh->b_jlist == jlist)
                return;
 
-       /* The following list of buffer states needs to be consistent
-        * with __jbd_unexpected_dirty_buffer()'s handling of dirty
-        * state. */
-
        if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
            jlist == BJ_Shadow || jlist == BJ_Forget) {
+               /*
+                * For metadata buffers, we track dirty bit in buffer_jbddirty
+                * instead of buffer_dirty. We should not see a dirty bit set
+                * here because we clear it in do_get_write_access but e.g.
+                * tune2fs can modify the sb and set the dirty bit at any time
+                * so we try to gracefully handle that.
+                */
+               if (buffer_dirty(bh))
+                       warn_dirty_buffer(bh);
                if (test_clear_buffer_dirty(bh) ||
                    test_clear_buffer_jbddirty(bh))
                        was_dirty = 1;