From: Juan Quintela <quintela@redhat.com>
Date: Thu, 4 Mar 2010 09:00:39 +0000 (+0100)
Subject: documentation: qemu_write_full don't work with non-blocking fd's
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1298cb6804d6073ef3cb9c06e663ee59d06d92cc;p=qemu.git

documentation: qemu_write_full don't work with non-blocking fd's

Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---

diff --git a/osdep.c b/osdep.c
index 5bf3c00fd1..abbc8a2381 100644
--- a/osdep.c
+++ b/osdep.c
@@ -261,6 +261,11 @@ int qemu_open(const char *name, int flags, ...)
  *
  * Return the number of bytes transferred.
  * Set errno if fewer than `count' bytes are written.
+ *
+ * This function don't work with non-blocking fd's.
+ * Any of the possibilities with non-bloking fd's is bad:
+ *   - return a short write (then name is wrong)
+ *   - busy wait adding (errno == EAGAIN) to the loop
  */
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 {