Bug 3291 – XIO writev doesn't handle iovcnt > IOVEC

Bug 3291 - XIO writev doesn't handle iovcnt > IOVEC

Summary:

XIO writev doesn't handle iovcnt > IOVEC

Status:	RESOLVED FIXED

Product:	XIO
Component:	Globus XIO
Version:	4.0.0
Platform:	Sun Solaris

Importance:	P3 normal
Target Milestone:	---
Assigned To:	John Bresnahan

URL:
Keywords:

Depends on:
Blocks:	3292
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Reported:	2005-05-04 16:04 by Joe Bester
Modified:	2005-05-05 09:58 (History)

Attachments
iovc_limit_patch.diff (1.48 KB, patch) 2005-05-04 16:50, Joe Bester	Details
Add an attachment (proposed patch, testcase, etc.)

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Description From Joe Bester 2005-05-04 16:04:19

When doing a writev with an iovec containing too many buffers, xio write fails
with "globus_xio: System error in writev: Invalid argument". It'd be nicer if
this  were handled somehow by the XIO drivers or system.

------- Comment #1 From John Bresnahan 2005-05-04 16:11:21 -------

This brings up interesting issues with drivers that are not reliable and
ordered.  May be a good time to introduce some driver description funtionality.

------- Comment #2 From Joe Bester 2005-05-04 16:50:57 -------

Created an attachment (id=601) [details]
iovc_limit_patch.diff

Attaching patch which keeps the iovc passed to writev and readv smaller than
IOVCNT.

------- Comment #3 From John Bresnahan 2005-05-04 17:14:40 -------

The udp driver is the only one that i am aware of that can't repass data down
the stack (semantically).  It properly handles any short write as a failure so
this patch is fine.  We need to add documentation to the driver code to say that
it is the drivers responsibility to deal with short reads/writes if it must have
all the data sent in a single packet.

Down the road we may want to add driver descriptors which tell the xio
framework, and other drivers, hints about a driver.  Things like ordered,
reliable, packet, stream, etc.  This would potientially allow the framework to
ease more burden on the driver.

------- Comment #4 From Joe Bester 2005-05-05 09:58:07 -------

Patch committed to 4.0 branch and trunk.
Added to advisories page.
Update package available at 
http://www-unix.globus.org/ftppub/gt4/4.0/4.0.0/updates/src/globus_xio-0.29.tar.gz