Re: [PATCH][RFC] incorrect direct io error handling (v3)

From: Dmitriy Monakhov
Date: Fri Jan 26 2007 - 02:59:46 EST


Andrew Morton <akpm@xxxxxxxx> writes:

> On Wed, 24 Jan 2007 22:05:06 +0300
> Dmitriy Monakhov <dmonakhov@xxxxx> wrote:
>
>> incorrect direct io error handling (v3)
>> Changes from v2:
>> - Remove BUG_ON(!mutex_is_locked(..)) for non blkdev.
>> - vmtruncate() called from generic_file_aio_write().
>> - depends on patch titled:
>> [PATH][RFC] mm: Move common segments checks to separate function
>
> drat, I skipped that patch due to rejects, and because Nick is working on
> things in the same area.
>
[skip]
>> if ((written >= 0 || written == -EIOCBQUEUED) &&
>> ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
>> @@ -2365,6 +2366,17 @@ ssize_t generic_file_aio_write(struct ki
>> &iocb->ki_pos);
>> mutex_unlock(&inode->i_mutex);
>>
>> + if (unlikely(ret < 0 && (file->f_flags & O_DIRECT))) {
>> + ssize_t cnt = generic_segment_checks(nr_segs, iov, VERIFY_READ);
>> + loff_t isize = i_size_read(inode);
>> + /*
>> + * generic_file_direct_write() may have instantiated a few
>> + * blocks outside i_size. Trim these off again.
>> + */
>> + if (cnt > 0 && (pos + cnt > isize))
>> + vmtruncate(inode, isize);
>> + }
>> +
>
> vmtruncate() really wants i_mutex to be held. Can't we do that here?
Yepp 110% true, baaahh ..... it looks like my brain was't clear at the time i
wrote this. We have to do vmtruncate() brfore droping i_mutex , right after
__generic_file_aio_write_nolock() call , i'm sorry to waste your time.


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