[PATCH] Fix RECVFILE with non-blocking sockets and add OEM recvfile call.

[Michael Adam]

pushed with minor adaption to commit msg. 

On 2014-05-22 at 13:56 -0700, Jeremy Allison wrote:
> On Thu, May 22, 2014 at 02:59:09PM +0200, Stefan (metze) Metzmacher wrote:
> > 
> > I'm getting EINVAL from splice if I use large io sizes, when using SMB3.
> > When count is truncated to TRANSFER_BUF_SIZE (128*1024) it works fine.
> > 
> > We should also make sure we don't get nwritten == 0 from splice,
> > as that would mean we're in an endless loop.
> 
> OK, looking at these patches closely, can you +1
> and add your 'Reviewed-by:' to the first of the
> two patches - that's the one that only fixes
> the non-splice recvfile (the read/write path
> in TRANSFER_BUF_SIZE (128*1024) chunks)
> to work correctly with a non-blocking
> socket.
> 
> That single fix (attached) is independent
> of the splice() code changes, and can
> be pushed independently. It would be good
> to get this in, as it allows people to
> turn on recvfile in SMB2 without needing
> a working splice and I'll work on the splice
> version later.
> 
> Thanks !
> 
> Jeremy

> From 854e864418cb146e038bd23f91111d54d687bea0 Mon Sep 17 00:00:00 2001
> From: Jeremy Allison <jra at samba.org>
> Date: Tue, 15 Apr 2014 12:43:06 -0700
> Subject: [PATCH] s3: smbd : default_sys_recvfile() and spice() recvfile were
>  not written to cope with non-blocking sockets.
> 
> When either the socket read() or splice() return
> -1 EWOULDBLOCK or EAGAIN, if no bytes have been
> processed yet return -1 and let the caller set
> blocking and retry. If bytes have been processed,
> just return them as a short read and let the
> caller retry with the remaining needed reads.
> 
> Signed-off-by: Jeremy Allison <jra at samba.org>
> ---
>  source3/lib/recvfile.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 44 insertions(+), 2 deletions(-)
> 
> diff --git a/source3/lib/recvfile.c b/source3/lib/recvfile.c
> index 500a7e4..bffe07f 100644
> --- a/source3/lib/recvfile.c
> +++ b/source3/lib/recvfile.c
> @@ -75,8 +75,33 @@ static ssize_t default_sys_recvfile(int fromfd,
>  		ssize_t read_ret;
>  		size_t toread = MIN(bufsize,count - total);
>  
> -		/* Read from socket - ignore EINTR. */
> -		read_ret = sys_read(fromfd, buffer, toread);
> +		/*
> +		 * Read from socket - ignore EINTR.
> +		 * Can't use sys_read() as that also
> +		 * ignores EAGAIN and EWOULDBLOCK.
> +		 */
> +		do {
> +			read_ret = read(fromfd, buffer, toread);
> +		} while (read_ret == -1 && errno == EINTR);
> +
> +#if defined(EWOULDBLOCK)
> +		if (read_ret == -1 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
> +#else
> +		if (read_ret == -1 && (errno == EAGAIN)) {
> +#endif
> +			/*
> +			 * fromfd socket is in non-blocking mode.
> +			 * If we already read some and wrote
> +			 * it successfully, return that.
> +			 * Only return -1 if this is the first read
> +			 * attempt. Caller will handle both cases.
> +			 */
> +			if (total_written != 0) {
> +				return total_written;
> +			}
> +			return -1;
> +		}
> +
>  		if (read_ret <= 0) {
>  			/* EOF or socket error. */
>  			return -1;
> @@ -184,6 +209,23 @@ ssize_t sys_recvfile(int fromfd,
>  				return default_sys_recvfile(fromfd, tofd,
>  							    offset, count);
>  			}
> +#if defined(EWOULDBLOCK)
> +			if (errno == EAGAIN || errno == EWOULDBLOCK) {
> +#else
> +			if (errno == EAGAIN) {
> +#endif
> +				/*
> +				 * fromfd socket is in non-blocking mode.
> +				 * If we already read some and wrote
> +				 * it successfully, return that.
> +				 * Only return -1 if this is the first read
> +				 * attempt. Caller will handle both cases.
> +				 */
> +				if (total_written != 0) {
> +					return total_written;
> +				}
> +				return -1;
> +			}
>  			break;
>  		}
>  
> -- 
> 1.9.1.423.g4596e3a
> 

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://lists.samba.org/pipermail/samba-technical/attachments/20140524/ad0c5ecc/attachment.pgp>