cvs commit: src/sys/kern vfs_cache.c vfs_subr.c src/sys/sys
dillon 2005/02/12 10:56:47 PST
DragonFly src repository
Modified files:
sys/kern vfs_cache.c vfs_subr.c
sys/sys namecache.h
Log:
Fix a cache_resolve() vs cache_inval() race which can result in a livelock.
The namecache invalidation code was being a bit overzealous when asked to
invalidate a subhierarchy. It was retrying until the subhierarchy was
completely invalidated, re-invalidating new entries created after the initial
call to cache_inval(). This can occur if the filesystem is heavily loaded
and a high level directory is being recursively invalidated.
It is unnecessary to retry in this case... the purpose is to invalidate
as-of the call to cache_inval(), so it is acceptable to allow new entries
to be resolved within the subhierarchy undergoing the invalidation.
Certain higher level entities... rename, and vnode reclamation, require
complete invalidation. The retry has been moved to a higher level for
these entities. The basic cache_inval() code is now single-pass.
Reported-by: Richard Nyberg <rnyberg@it.su.se>
Revision Changes Path
1.51 +52 -16 src/sys/kern/vfs_cache.c
1.52 +4 -1 src/sys/kern/vfs_subr.c
1.19 +2 -2 src/sys/sys/namecache.h
http://www.dragonflybsd.org/cvsweb/src/sys/kern/vfs_cache.c.diff?r1=1.50&r2=1.51&f=u
http://www.dragonflybsd.org/cvsweb/src/sys/kern/vfs_subr.c.diff?r1=1.51&r2=1.52&f=u
http://www.dragonflybsd.org/cvsweb/src/sys/sys/namecache.h.diff?r1=1.18&r2=1.19&f=u