From: Christoph Hellwig <hch@infradead.org>
To: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
hch@infradead.org, darrick.wong@oracle.com
Subject: Re: [PATCH v2] iomap: return partial I/O count on error in iomap_dio_bio_actor
Date: Tue, 25 Feb 2020 12:53:42 -0800 [thread overview]
Message-ID: <20200225205342.GA12066@infradead.org> (raw)
In-Reply-To: <20200221045110.612705204E@d06av21.portsmouth.uk.ibm.com>
On Fri, Feb 21, 2020 at 10:21:04AM +0530, Ritesh Harjani wrote:
> > if (dio->error) {
> > iov_iter_revert(dio->submit.iter, copied);
> > - copied = ret = 0;
> > + ret = 0;
> > goto out;
> > }
>
> But if I am seeing this correctly, even after there was a dio->error
> if you return copied > 0, then the loop in iomap_dio_rw will continue
> for next iteration as well. Until the second time it won't copy
> anything since dio->error is set and from there I guess it may return
> 0 which will break the loop.
In addition to that copied is also iov_iter_reexpand call. We don't
really need the re-expand in case of errors, and in fact we also
have the iov_iter_revert call before jumping out, so this will
need a little bit more of an audit and properly documented in the
commit log.
>
> Is this the correct flow? Shouldn't the while loop doing
> iomap_apply in iomap_dio_rw should also break in case of
> dio->error? Or did I miss anything?
We'd need something there iff we care about a good number of written
in case of the error. Goldwyn, can you explain what you need this
number for in btrfs? Maybe with a pointer to the current code base?
next prev parent reply other threads:[~2020-02-25 20:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-20 15:23 [PATCH v2] iomap: return partial I/O count on error in iomap_dio_bio_actor Goldwyn Rodrigues
2020-02-20 17:42 ` Matthew Wilcox
2020-02-21 2:06 ` Goldwyn Rodrigues
2020-02-21 4:51 ` Ritesh Harjani
2020-02-21 12:48 ` Goldwyn Rodrigues
2020-02-25 20:53 ` Christoph Hellwig [this message]
2020-02-26 2:12 ` Damien Le Moal
2020-02-26 2:55 ` Goldwyn Rodrigues
2020-02-28 19:44 ` Goldwyn Rodrigues
2020-02-28 19:59 ` Matthew Wilcox
2020-02-28 20:35 ` Goldwyn Rodrigues
2020-03-02 13:31 ` Christoph Hellwig
2020-02-21 13:14 ` David Sterba
2020-02-20 15:24 Goldwyn Rodrigues
2020-03-19 15:08 Goldwyn Rodrigues
2020-03-20 14:05 ` Christoph Hellwig
2020-03-20 14:23 ` Josef Bacik
2020-03-20 14:35 ` Christoph Hellwig
2020-03-20 15:35 ` Goldwyn Rodrigues
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