From ba44bc49bae6e9e25630388fefbbaa6c6bdd0a11 Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Fri, 8 Sep 2017 17:48:55 +0900 Subject: [PATCH] btrfs: propagate error to btrfs_cmp_data_prepare caller commit 78ad4ce014d025f41b8dde3a81876832ead643cf upstream. btrfs_cmp_data_prepare() (almost) always returns 0 i.e. ignoring errors from gather_extent_pages(). While the pages are freed by btrfs_cmp_data_free(), cmp->num_pages still has > 0. Then, btrfs_extent_same() try to access the already freed pages causing faults (or violates PageLocked assertion). This patch just return the error as is so that the caller stop the process. Signed-off-by: Naohiro Aota Fixes: f441460202cb ("btrfs: fix deadlock with extent-same and readpage") Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 1782804..90185e9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3052,7 +3052,7 @@ static int btrfs_cmp_data_prepare(struct inode *src, u64 loff, out: if (ret) btrfs_cmp_data_free(cmp); - return 0; + return ret; } static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst, -- 2.7.4