From: Wang Sheng-Hui <shhuiw@gmail.com> When use crc area, we should check if it can host the desired num of crcs. Add the check in init stage. And the check should be more strict: the first page has sizeof(u64)*2 cannot used for crc. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> --- fs/btrfs/free-space-cache.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 4ea66d4..058fc9b 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -286,8 +286,14 @@ static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode, if (!io_ctl->pages) return -ENOMEM; io_ctl->root = root; - if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID) + if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID) { io_ctl->check_crcs = 1; + if ((io_ctl.num_pages * sizeof(u32)) > + (PAGE_CACHE_SIZE - sizeof(u64) * 2)) { + WARN_ON(1); + return -1; + } + } return 0; } @@ -917,7 +923,8 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, /* Make sure we can fit our crcs into the first page */ if (io_ctl.check_crcs && - (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) { + (io_ctl.num_pages * sizeof(u32)) > + (PAGE_CACHE_SIZE - sizeof(u64) * 2)) { WARN_ON(1); goto out_nospc; } -- 1.6.0.2 -- 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