4.16-stable review patch. If anyone has any objections, please let me know.
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From: Su Yue suy.fnst@cn.fujitsu.com
commit 090a127afa8f73e9618d4058d6755f7ec7453dd6 upstream.
In cow_file_range(), create_io_em() may fail, but its return value is not recorded. Then return value may be 0 even it failed which is a wrong behavior.
Let cow_file_range() return PTR_ERR(em) if create_io_em() failed.
Fixes: 6f9994dbabe5 ("Btrfs: create a helper to create em for IO") CC: stable@vger.kernel.org # 4.11+ Signed-off-by: Su Yue suy.fnst@cn.fujitsu.com Reviewed-by: Nikolay Borisov nborisov@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/inode.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1037,8 +1037,10 @@ static noinline int cow_file_range(struc ram_size, /* ram_bytes */ BTRFS_COMPRESS_NONE, /* compress_type */ BTRFS_ORDERED_REGULAR /* type */); - if (IS_ERR(em)) + if (IS_ERR(em)) { + ret = PTR_ERR(em); goto out_reserve; + } free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,