Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

2 files changed, 52 insertions, 47 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 18bfd5dab64..e378cb38397 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -297,6 +297,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 	unsigned int new_offset;
 	struct buffer_head *bh_in = jh2bh(jh_in);
 	struct jbd2_buffer_trigger_type *triggers;
+	journal_t *journal = transaction->t_journal;
 
 	/*
 	 * The buffer really shouldn't be locked: only the current committing
@@ -310,6 +311,11 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 	J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
 
 	new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
+	/* keep subsequent assertions sane */
+	new_bh->b_state = 0;
+	init_buffer(new_bh, NULL, NULL);
+	atomic_set(&new_bh->b_count, 1);
+	new_jh = jbd2_journal_add_journal_head(new_bh);	/* This sleeps */
 
 	/*
 	 * If a new transaction has already done a buffer copy-out, then
@@ -388,14 +394,6 @@ repeat:
 		kunmap_atomic(mapped_data, KM_USER0);
 	}
 
-	/* keep subsequent assertions sane */
-	new_bh->b_state = 0;
-	init_buffer(new_bh, NULL, NULL);
-	atomic_set(&new_bh->b_count, 1);
-	jbd_unlock_bh_state(bh_in);
-
-	new_jh = jbd2_journal_add_journal_head(new_bh);	/* This sleeps */
-
 	set_bh_page(new_bh, new_page, new_offset);
 	new_jh->b_transaction = NULL;
 	new_bh->b_size = jh2bh(jh_in)->b_size;
@@ -412,7 +410,11 @@ repeat:
 	 * copying is moved to the transaction's shadow queue.
 	 */
 	JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
-	jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
+	spin_lock(&journal->j_list_lock);
+	__jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
+	spin_unlock(&journal->j_list_lock);
+	jbd_unlock_bh_state(bh_in);
+
 	JBUFFER_TRACE(new_jh, "file as BJ_IO");
 	jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
 
@@ -2410,6 +2412,7 @@ const char *jbd2_dev_to_name(dev_t device)
 	int	i = hash_32(device, CACHE_SIZE_BITS);
 	char	*ret;
 	struct block_device *bd;
+	static struct devname_cache *new_dev;
 
 	rcu_read_lock();
 	if (devcache[i] && devcache[i]->device == device) {
@@ -2419,20 +2422,20 @@ const char *jbd2_dev_to_name(dev_t device)
 	}
 	rcu_read_unlock();
 
+	new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL);
+	if (!new_dev)
+		return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
 	spin_lock(&devname_cache_lock);
 	if (devcache[i]) {
 		if (devcache[i]->device == device) {
+			kfree(new_dev);
 			ret = devcache[i]->devname;
 			spin_unlock(&devname_cache_lock);
 			return ret;
 		}
 		call_rcu(&devcache[i]->rcu, free_devcache);
 	}
-	devcache[i] = kmalloc(sizeof(struct devname_cache), GFP_KERNEL);
-	if (!devcache[i]) {
-		spin_unlock(&devname_cache_lock);
-		return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
-	}
+	devcache[i] = new_dev;
 	devcache[i]->device = device;
 	bd = bdget(device);
 	if (bd) {
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 494501edba6..6213ac728f3 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -499,34 +499,15 @@ void jbd2_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);
 }
 
 /*
@@ -593,14 +574,16 @@ 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);
@@ -843,6 +826,15 @@ int jbd2_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 jbd2_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 */
@@ -1644,8 +1636,13 @@ 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);
 		__jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
-		clear_buffer_jbddirty(bh);
 		may_free = 0;
 	} else {
 		JBUFFER_TRACE(jh, "on running transaction");
@@ -1896,12 +1893,17 @@ void __jbd2_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;