Date: Mon, 6 Dec 2004 18:52:28 +0000 (UTC) From: Paul Saab <ps@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/nfsclient nfs_bio.c nfs_node.c nfs_vnops.c nfsnode.h Message-ID: <200412061852.iB6IqSGV000126@repoman.freebsd.org>
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ps 2004-12-06 18:52:28 UTC
FreeBSD src repository
Modified files:
sys/nfsclient nfs_bio.c nfs_node.c nfs_vnops.c
nfsnode.h
Log:
Serialize NFS vinvalbuf operations by acquiring/upgrading to the
vnode EXCLUSIVE lock. This prevents threads from adding pages to
the vnode while an invalidation is in progress, closing potential
races. In the bioread() path, callers acquire the SHARED vnode lock
- so while an invalidate was in progress, it was possible to fault
in new pages onto the vnode causing the invalidation to take a while
or fail. We saw these races at Yahoo! with very large files+heavy
concurrent access. Forcing an upgrade to EXCLUSIVE lock before doing
the invalidation closes all these races.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Revision Changes Path
1.141 +23 -26 src/sys/nfsclient/nfs_bio.c
1.70 +1 -1 src/sys/nfsclient/nfs_node.c
1.235 +0 -2 src/sys/nfsclient/nfs_vnops.c
1.49 +0 -2 src/sys/nfsclient/nfsnode.h
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