Date: Mon, 21 Jun 1999 18:39:58 -0700 (PDT) From: Kirk McKusick <mckusick@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/kern vfs_bio.c Message-ID: <199906220139.SAA39500@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
mckusick 1999/06/21 18:39:57 PDT
Modified files:
sys/kern vfs_bio.c
Log:
When allocating new buffers in getnewbuf, there are several points
at which we may sleep. So, after completing our buffer allocation
we must ensure that another process has not come along and allocated
a different buffer with the same identity. We do this by keeping a
global counter of the number of buffers that getnewbuf has allocated.
We save this count when we enter getnewbuf and check it when we are
about to return. If it has changed, then other buffers were allocated
while we were in getnewbuf, so we must return NULL to let our parent
know that it must recheck to see if it still needs the new buffer.
Hopefully this fix will eliminate the creation of duplicate buffers
with the same identity and the obscure corruptions that they cause.
Revision Changes Path
1.215 +40 -11 src/sys/kern/vfs_bio.c
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199906220139.SAA39500>