From 8e94af8e2b582e5915abc171a28130881d1c26e4 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 25 Jul 2012 09:32:40 -0500 Subject: [PATCH] rbd: encapsulate header validity test If an rbd image header is read and it doesn't begin with the expected magic information, a warning is displayed. This is a fairly simple test, but it could be extended at some point. Fix the comparison so it actually looks at the "text" field rather than the front of the structure. In any case, encapsulate the validity test in its own function. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index bb7f436..ae65fac 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -481,6 +481,12 @@ static void rbd_coll_release(struct kref *kref) kfree(coll); } +static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk) +{ + return !memcmp(&ondisk->text, + RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)); +} + /* * Create a new header structure, translate header format from the on-disk * header. @@ -492,7 +498,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header, { u32 i, snap_count; - if (memcmp(ondisk, RBD_HEADER_TEXT, sizeof(RBD_HEADER_TEXT))) + if (!rbd_dev_ondisk_valid(ondisk)) return -ENXIO; snap_count = le32_to_cpu(ondisk->snap_count); -- 2.7.4