btrfs-progs: use on-stack buffer for dev_to_fsid

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index c6ed388..25317fa 100644 (file)
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -510,18 +510,13 @@ out:
 static int dev_to_fsid(char *dev, __u8 *fsid)
 {
        struct btrfs_super_block *disk_super;
-       char *buf;
+       char buf[BTRFS_SUPER_INFO_SIZE];
        int ret;
        int fd;
 
-       buf = malloc(4096);
-       if (!buf)
-               return -ENOMEM;
-
        fd = open(dev, O_RDONLY);
        if (fd < 0) {
                ret = -errno;
-               free(buf);
                return ret;
        }
 
@@ -536,7 +531,6 @@ static int dev_to_fsid(char *dev, __u8 *fsid)
 
 out:
        close(fd);
-       free(buf);
        return ret;
 }