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Message-ID: <1540000565.3151.9.camel@slavad-ubuntu-14.04>
Subject: Re: [PATCH 2/2] hfs: fix return value of hfs_get_block()
From: Viacheslav Dubeyko <slava@dubeyko.com>
To: "Ernesto A." =?ISO-8859-1?Q?Fern=E1ndez?=
        <ernesto.mnd.fernandez@gmail.com>
Cc: linux-fsdevel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Date: Fri, 19 Oct 2018 18:56:05 -0700
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On Wed, 2018-10-10 at 15:24 -0300, Ernesto A. Fernández wrote:
> Direct writes to empty inodes fail with EIO.  The generic direct-io code
> is in part to blame (a patch has been submitted as "direct-io: allow
> direct writes to empty inodes"), but hfs is worse affected than the
> other filesystems because the fallback to buffered I/O doesn't happen.
> 
> The problem is the return value of hfs_get_block() when called with
> !create.  Change it to be more consistent with the other modules.
> 
> Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
> ---
>  fs/hfs/extent.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
> index 0c638c612152..5f1ff97a3b98 100644
> --- a/fs/hfs/extent.c
> +++ b/fs/hfs/extent.c
> @@ -345,7 +345,9 @@ int hfs_get_block(struct inode *inode, sector_t block,
>  	ablock = (u32)block / HFS_SB(sb)->fs_div;
>  
>  	if (block >= HFS_I(inode)->fs_blocks) {
> -		if (block > HFS_I(inode)->fs_blocks || !create)
> +		if (!create)
> +			return 0;
> +		if (block > HFS_I(inode)->fs_blocks)
>  			return -EIO;
>  		if (ablock >= HFS_I(inode)->alloc_blocks) {
>  			res = hfs_extend_file(inode);

Looks good. Finally, I think it should work properly.

Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>

Thanks,
Vyacheslav Dubeyko.