From c41570c9d29764f797fa35490d72b7395a0105c3 Mon Sep 17 00:00:00 2001 From: Justin Maggard Date: Tue, 21 Jan 2014 11:18:29 -0800 Subject: [PATCH] btrfs: fix defrag 32-bit integer overflow When defragging a very large file, the cluster variable can wrap its 32-bit signed int type and become negative, which eventually gets passed to btrfs_force_ra() as a very large unsigned long value. On 32-bit platforms, this eventually results in an Oops from the SLAB allocator. Change the cluster and max_cluster signed int variables to unsigned long to match the readahead functions. This also allows the min() comparison in btrfs_defrag_file() to work as intended. Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 62c62b4..34772cb 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1036,7 +1036,7 @@ out: static int cluster_pages_for_defrag(struct inode *inode, struct page **pages, unsigned long start_index, - int num_pages) + unsigned long num_pages) { unsigned long file_end; u64 isize = i_size_read(inode); @@ -1194,8 +1194,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, int defrag_count = 0; int compress_type = BTRFS_COMPRESS_ZLIB; int extent_thresh = range->extent_thresh; - int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; - int cluster = max_cluster; + unsigned long max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; + unsigned long cluster = max_cluster; u64 new_align = ~((u64)128 * 1024 - 1); struct page **pages = NULL; -- 2.7.4