Re: [PATCH v3] xfs: Check for delayed allocations before setting extsize

["Darrick J. Wong" <djwong@kernel.org>]

On Fri, Oct 11, 2024 at 08:24:27PM +0530, Ojaswin Mujoo wrote:
> Extsize is allowed to be set on files with no data in it. For this,
> we were checking if the files have extents but missed to check if
> delayed extents were present. This patch adds that check.
> 
> While we are at it, also refactor this check into a helper since
> its used in some other places as well like xfs_inactive() or
> xfs_ioctl_setattr_xflags()
> 
> **Without the patch (SUCCEEDS)**
> 
> $ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536'
> 
> wrote 1024/1024 bytes at offset 0
> 1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec)
> 
> **With the patch (FAILS as expected)**
> 
> $ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536'
> 
> wrote 1024/1024 bytes at offset 0
> 1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec)
> xfs_io: FS_IOC_FSSETXATTR testfile: Invalid argument
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>

Looks good now,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_inode.c | 2 +-
>  fs/xfs/xfs_inode.h | 5 +++++
>  fs/xfs/xfs_ioctl.c | 4 ++--
>  3 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index bcc277fc0a83..19dcb569a3e7 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -1409,7 +1409,7 @@ xfs_inactive(
>  
>  	if (S_ISREG(VFS_I(ip)->i_mode) &&
>  	    (ip->i_disk_size != 0 || XFS_ISIZE(ip) != 0 ||
> -	     ip->i_df.if_nextents > 0 || ip->i_delayed_blks > 0))
> +	     xfs_inode_has_filedata(ip)))
>  		truncate = 1;
>  
>  	if (xfs_iflags_test(ip, XFS_IQUOTAUNCHECKED)) {
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index 97ed912306fd..03944b6c5fba 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -292,6 +292,11 @@ static inline bool xfs_is_cow_inode(struct xfs_inode *ip)
>  	return xfs_is_reflink_inode(ip) || xfs_is_always_cow_inode(ip);
>  }
>  
> +static inline bool xfs_inode_has_filedata(const struct xfs_inode *ip)
> +{
> +	return ip->i_df.if_nextents > 0 || ip->i_delayed_blks > 0;
> +}
> +
>  /*
>   * Check if an inode has any data in the COW fork.  This might be often false
>   * even for inodes with the reflink flag when there is no pending COW operation.
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index a20d426ef021..2567fd2a0994 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -481,7 +481,7 @@ xfs_ioctl_setattr_xflags(
>  
>  	if (rtflag != XFS_IS_REALTIME_INODE(ip)) {
>  		/* Can't change realtime flag if any extents are allocated. */
> -		if (ip->i_df.if_nextents || ip->i_delayed_blks)
> +		if (xfs_inode_has_filedata(ip))
>  			return -EINVAL;
>  
>  		/*
> @@ -602,7 +602,7 @@ xfs_ioctl_setattr_check_extsize(
>  	if (!fa->fsx_valid)
>  		return 0;
>  
> -	if (S_ISREG(VFS_I(ip)->i_mode) && ip->i_df.if_nextents &&
> +	if (S_ISREG(VFS_I(ip)->i_mode) && xfs_inode_has_filedata(ip) &&
>  	    XFS_FSB_TO_B(mp, ip->i_extsize) != fa->fsx_extsize)
>  		return -EINVAL;
>  
> -- 
> 2.43.5
> 
>