Re: [PATCH] xfs_db: don't put null inode

[Eric Sandeen <sandeen@sandeen.net>]

Ugh subject should be xfs_db of course :/

Eric Sandeen wrote:
> John Willis pointed this out:
> 
> $ sudo xfs_db -x /dev/evms/RAID5-SATA-1 
> cache_node_purge: refcount was 1, not zero (node=0x80dd660)
> xfs_db: cannot read root inode (22)
> cache_node_purge: refcount was 1, not zero (node=0x80e0008)
> xfs_db: cannot read realtime bitmap inode (22)
> Segmentation fault
> 
> it dies when pthread code gets a null ptr, like this:
> 
> (gdb) bt
> #0  0x0000003ef1c08309 in pthread_mutex_lock () from /lib64/libpthread.so.0
> #1  0x000000000044f5af in cache_node_put (cache=0x25a2030, node=0x0) at cache.c:368
> #2  0x000000000041ff7e in libxfs_mount (mp=0x0, sb=<value optimized out>, dev=<value optimized out>, logdev=<value optimized out>, 
>     rtdev=<value optimized out>, flags=1) at init.c:680
> #3  0x0000000000416157 in init (argc=2, argv=0x7fffd9e19798) at init.c:125
> #4  0x000000000041635a in main (argc=48, argv=0x7fffd9e19798) at init.c:153
> (gdb) 
> 
> when reading the root inode fails, and we try to libxfs_iput it anyway.
> 
> The following seems to fix it ...
> 
> -Eric
> 
> Index: xfsprogs/libxfs/init.c
> ===================================================================
> --- xfsprogs.orig/libxfs/init.c
> +++ xfsprogs/libxfs/init.c
> @@ -677,7 +677,8 @@ libxfs_mount(
>  		ASSERT(mp->m_rootip != NULL);
>  	}
>  	if ((flags & LIBXFS_MOUNT_ROOTINOS) && rtmount_inodes(mp)) {
> -		libxfs_iput(mp->m_rootip, 0);
> +		if (mp->m_rootip)
> +			libxfs_iput(mp->m_rootip, 0);
>  		return NULL;
>  	}
>  
> 
>