pnfs/blocklayout: Ensure disk address in block device map

It's possible that the device map is smaller than the offset into the device
for the I/O we're adding.  Add a check for it and bail out, otherwise we
risk botching the bio calculations that follow.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trondmy@gmail.com>

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index ca6cf54b54df397ba0978eaa7935a2acea6c09e2..7cb5c38c19e4f7386902740f9575a070bd15687b 100644 (file)
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -137,6 +137,11 @@ bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector,
        return bio;
 }
 
+static bool offset_in_map(u64 offset, struct pnfs_block_dev_map *map)
+{
+       return offset >= map->start && offset < map->start + map->len;
+}
+
 static struct bio *
 do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect,
                struct page *page, struct pnfs_block_dev_map *map,
@@ -156,8 +161,8 @@ do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect,
 
        /* translate to physical disk offset */
        disk_addr = (u64)isect << SECTOR_SHIFT;
-       if (disk_addr < map->start || disk_addr >= map->start + map->len) {
-               if (!dev->map(dev, disk_addr, map))
+       if (!offset_in_map(disk_addr, map)) {
+               if (!dev->map(dev, disk_addr, map) || !offset_in_map(disk_addr, map))
                        return ERR_PTR(-EIO);
                bio = bl_submit_bio(bio);
        }