Date: Thu, 5 Apr 2007 20:49:46 +0000 (UTC) From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/vm vm_fault.c Message-ID: <200704052049.l35KnkwZ009352@repoman.freebsd.org>
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pjd 2007-04-05 20:49:46 UTC
FreeBSD src repository
Modified files:
sys/vm vm_fault.c
Log:
Fix a problem for file systems that don't implement VOP_BMAP() operation.
The problem is this: vm_fault_additional_pages() calls vm_pager_has_page(),
which calls vnode_pager_haspage(). Now when VOP_BMAP() returns an error (eg.
EOPNOTSUPP), vnode_pager_haspage() returns TRUE without initializing 'before'
and 'after' arguments, so we have some accidental values there. This bascially
was causing this condition to be meet:
if ((rahead + rbehind) >
((cnt.v_free_count + cnt.v_cache_count) - cnt.v_free_reserved)) {
pagedaemon_wakeup();
[...]
}
(we have some random values in rahead and rbehind variables)
I'm not entirely sure this is the right fix, maybe we should just return FALSE
in vnode_pager_haspage() when VOP_BMAP() fails?
alc@ knows about this problem, maybe he will be able to come up with a better
fix if this is not the right one.
Revision Changes Path
1.226 +2 -0 src/sys/vm/vm_fault.c
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