readv() return and errno

[Balbir Singh]

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You are right, the latest POSIX spec says

ERRORS
....
The readv() function may fail if:

[EINVAL]
The iovcnt argument was less than or equal to 0, or
greater than {IOV_MAX}

Apply this trivial patch, if you want the required
behaviour (see attached)

Balbir

List:     linux-kernel
Subject:  readv() return and errno
From:     "Jim Hollenback" <[e-mail]>
Date:     2002-03-15 21:54:26
[Download message RAW]

In doing some testing on the project I'm working on I 
came across something that is causing a bit of 
confusion on my part.

According to readv(2) EINVAL is returned for an 
invalid  argument.  The examples given were count
might 
be greater than MAX_IOVEC or zero. The test case I am 
working with has count = 0 and I get return of 0 and 
errno 0 instead of the expected -1 and errno EINVAL.

Am I missing something?

Thanks!

Jim Hollenback

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--- read_write.c.org	Fri Mar 15 16:10:05 2002
+++ read_write.c	Fri Mar 15 16:10:13 2002
@@ -241,10 +241,9 @@
 	 * First get the "struct iovec" from user memory and
 	 * verify all the pointers
 	 */
-	ret = 0;
+	ret = -EINVAL;
 	if (!count)
 		goto out_nofree;
-	ret = -EINVAL;
 	if (count > UIO_MAXIOV)
 		goto out_nofree;
 	if (!file->f_op)

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