btrfs-progs: check fopen failure in cmds-send

Check for fopen() failure.  This shows up in static analysis as a
possible null pointer derference.

Signed-off-by: Zach Brown <zab@redhat.com>
Laughed-at-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/cmds-send.c b/cmds-send.c
index 374d040..81b3e49 100644 (file)
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -72,6 +72,9 @@ int find_mount_root(const char *path, char **mount_root)
        close(fd);
 
        mnttab = fopen("/proc/mounts", "r");
+       if (!mnttab)
+               return -errno;
+
        while ((ent = getmntent(mnttab))) {
                len = strlen(ent->mnt_dir);
                if (strncmp(ent->mnt_dir, path, len) == 0) {