Re: [PATCH] xfs: Set xfs_buf type flag when growing summary/bitmap files

Christoph Hellwig
2020-09-14T07:25:04Z

On Sat, Sep 12, 2020 at 06:30:15PM +0530, Chandan Babu R wrote:
> The following sequence of commands,
>
> mkfs.xfs -f -m reflink=0 -r rtdev=/dev/loop1,size=10M /dev/loop0
> mount -o rtdev=/dev/loop1 /dev/loop0 /mnt
> xfs_growfs /mnt
>
> ... causes the following call trace to be printed on the console,
>
> XFS: Assertion failed: (bip->bli_flags & XFS_BLI_STALE) || (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF), file: fs/xfs/xfs_buf_item.c, line: 331
> Call Trace:
> xfs_buf_item_format+0x632/0x680
> ? kmem_alloc_large+0x29/0x90
> ? kmem_alloc+0x70/0x120
> ? xfs_log_commit_cil+0x132/0x940
> xfs_log_commit_cil+0x26f/0x940
> ? xfs_buf_item_init+0x1ad/0x240
> ? xfs_growfs_rt_alloc+0x1fc/0x280
> __xfs_trans_commit+0xac/0x370
> xfs_growfs_rt_alloc+0x1fc/0x280
> xfs_growfs_rt+0x1a0/0x5e0
> xfs_file_ioctl+0x3fd/0xc70
> ? selinux_file_ioctl+0x174/0x220
> ksys_ioctl+0x87/0xc0
> __x64_sys_ioctl+0x16/0x20
> do_syscall_64+0x3e/0x70
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> This occurs because the buffer being formatted has the value of
> XFS_BLFT_UNKNOWN_BUF assigned to the 'type' subfield of
> bip->bli_formats->blf_flags.
>
> This commit fixes the issue by assigning one of XFS_BLFT_RTSUMMARY_BUF
> and XFS_BLFT_RTBITMAP_BUF to the 'type' subfield of
> bip->bli_formats->blf_flags before committing the corresponding
> transaction.
>
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
> fs/xfs/xfs_rtalloc.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index 6209e7b6b895..192a69f307d7 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -767,8 +767,12 @@ xfs_growfs_rt_alloc(
> struct xfs_bmbt_irec map; /* block map output */
> int nmap; /* number of block maps */
> int resblks; /* space reservation */
> + enum xfs_blft buf_type;
> struct xfs_trans *tp;
>
> + buf_type = (ip == mp->m_rsumip) ?
> + XFS_BLFT_RTSUMMARY_BUF : XFS_BLFT_RTBITMAP_BUF;

Nit: can you turn this into a normal if / else?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>