Re: kern/57307: panic: ffs_blkfree: bad size

[Chuck Silvers <chuq%chuq.com@localhost>]

The following reply was made to PR kern/57307; it has been noted by GNATS.

From: Chuck Silvers <chuq%chuq.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/57307: panic: ffs_blkfree: bad size
Date: Wed, 29 Mar 2023 07:31:06 -0700

 On Wed, Mar 29, 2023 at 07:55:00AM +0000, manu%netbsd.org@localhost wrote:
 > Snapshot is created with 
 > fss_flags = FSS_UNCONFIG_ON_CLOSE|unlink_on_create
 > Backing store is truncate()'ed to  vfs.f_blocks * vfs.f_frsize which means the size of the partition, 14 To.
 
 could you please supply the source for the program you're using to create the snapshot?
 
 
 > The panic is 
 > panic: ffs_blkfree: bad size: dev = 0xa804, bno = 1 bsize = 32768, size = 32768, fs = /raid0
 
 "bno = 1" means that this is probably a UFS native snapshot inode,
 which uses special bno values such as:
 
 #define	BLK_NOCOPY	((daddr_t)(1))
 
 ffs_truncate() is supposed to call ffs_snapremove() to remove all of the special
 bno values from the bmap before going into the normal loop to free real blocks,
 but it looks like somehow that is not happening.
 
 -Chuck