From: Badari Pulavarty Date: Fri, 22 Dec 2006 09:06:23 +0000 (-0800) Subject: [PATCH] Fix for shmem_truncate_range() BUG_ON() X-Git-Tag: v2.6.20-rc2~53 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=92a3d03aab912624cae799e5772a6eb2ef55083f;p=linux-2.6 [PATCH] Fix for shmem_truncate_range() BUG_ON() Ran into BUG() while doing madvise(REMOVE) testing. If we are punching a hole into shared memory segment using madvise(REMOVE) and the entire hole is below the indirect blocks, we hit following assert. BUG_ON(limit <= SHMEM_NR_DIRECT); Signed-off-by: Badari Pulavarty Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/shmem.c b/mm/shmem.c index 4bb28d218e..70da7a0981 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -515,7 +515,12 @@ static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end) size = SHMEM_NR_DIRECT; nr_swaps_freed = shmem_free_swp(ptr+idx, ptr+size); } - if (!topdir) + + /* + * If there are no indirect blocks or we are punching a hole + * below indirect blocks, nothing to be done. + */ + if (!topdir || (punch_hole && (limit <= SHMEM_NR_DIRECT))) goto done2; BUG_ON(limit <= SHMEM_NR_DIRECT);