Messages in this thread | | | Date | Wed, 06 May 2015 08:40:54 -0600 | From | Jens Axboe <> | Subject | Re: [PATCH v2] splice: sendfile() at once fails for big files |
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On 05/06/2015 08:38 AM, leroy christophe wrote: > > Le 06/05/2015 16:23, Jens Axboe a écrit : >> On 05/05/2015 09:41 PM, Linus Torvalds wrote: >>> Jens, ping? >>> >>> The test results should make this a no-brainer, but I hate how random >>> these flag ops. >> >> Missed the original, apparently. I too am confused how this is a >> correctness fix and not just an optimization. >> >> + if (read_len < len) >> + sd->flags |= SPLICE_F_MORE; >> + else if (!more) >> + sd->flags &= ~SPLICE_F_MORE; >> >> Should that check be for 'more', not '!more'? >> >> > @@ -1204,6 +1204,7 @@ ssize_t splice_direct_to_actor(struct file *in, > struct splice_desc *sd, > * Don't block on output, we have to drain the direct pipe. > */ > sd->flags &= ~SPLICE_F_NONBLOCK; > + more = sd->flags & SPLICE_F_MORE; > > while (len) { > size_t read_len; > @@ -1216,6 +1217,10 @@ ssize_t splice_direct_to_actor(struct file *in, > struct splice_desc *sd, > read_len = ret; > sd->total_len = read_len; > > + if (read_len < len) > + sd->flags |= SPLICE_F_MORE; > + else if (!more) > + sd->flags &= ~SPLICE_F_MORE; > > > > 'more' contains whether sendfile() has been called with SPLICE_F_MORE or > not. > Until all bytes are processed, we have to force SPLICE_F_MORE regardless > of how sendfile() was called. > Once all bytes have been read, we have to reset the flags according to > how sendfile() was called, so if 'more' is NOT set, we have to clear > SPLICE_F_MORE from sd->flags (which was unconditionaly set for > processing the first bytes)
Ah gotcha, that looks correct. Patch is fine with me then.
-- Jens Axboe
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