Btrfs devel - Apr 2013 - [PATCH] Btrfs: don't call readahead hook until we have read the entire eb

Martin Steigerwald reported a BUG_ON() where we were given a bogus bytenr to
map.  Turns out he is using > PAGESIZE leafsizes.  The readahead stuff is
called
every time we do a completion, but we may not have finished reading in all the
pages, so the bytenr we read off the node could be completely bogus.  Fix this
by only calling the readahead hook once all pages have been read in.  Thanks,

Reported-by: Martin Steigerwald <Martin@lichtvoll.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
 fs/btrfs/disk-io.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fa8438f..f4628c7 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -674,10 +674,9 @@ static int btree_readpage_end_io_hook(struct page *page,
u64 start, u64 end,
 	if (!ret)
 		set_extent_buffer_uptodate(eb);
 err:
-	if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
-		clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
+	if (reads_done &&
+	    test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))
 		btree_readahead_hook(root, eb, eb->start, ret);
-	}
 
 	if (ret) {
 		/*
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs"
in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html