[PATCH 15/19] mkfs: don't treat files as though they are block devices

[Eric Sandeen]

On 4/7/16 7:25 PM, Eric Sandeen wrote:
>> @@ -1299,15 +1370,23 @@ zero_old_xfs_structures(
>> >  	}
>> >  	memset(buf, 0, new_sb->sb_sectsize);
>> >  
>> > -	tmp = pread(xi->dfd, buf, new_sb->sb_sectsize, 0);
>> > -	if (tmp < 0) {
>> > +	off = pread(xi->dfd, buf, new_sb->sb_sectsize, 0);
>> > +	if (off < 0) {
>> >  		fprintf(stderr, _("existing superblock read failed: %s\n"),
>> >  			strerror(errno));
>> >  		goto done;
>> >  	}
>> > -	if (tmp != new_sb->sb_sectsize) {
>> > -		fprintf(stderr,
>> > -	_("warning: could not read existing superblock, skip zeroing\n"));
>> > +	/*
>> > +	 * If we are creating an image file, it might be of zero length at this
>> > +	 * point in time. Hence reading the existing superblock is going to
>> > +	 * return zero bytes. It's not a failure we need to warn about in this
>> > +	 * case.
>> > +	 */
> except you already did "if (off < 0) fail" above this.

(oh, right, < 0 is different than == 0, sorry; so that part is ok)

Possibly better as:

if (off < 0 || (tmp != new_sb->sb_sectsize && !xi->disfile))
	fprintf("error reading existing superblock ...")

I still think this patch might need a reset though :)

Thanks,
-Eric

> Ok, at this point I think it might be best to revert to Dave's original version.
> 
> If there were specific problems you were trying to address, can you point them out?
> 
> Thanks,
> -Eric
>