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- Include opt_vfs.h for LOOKUP_SHARED.

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- Control the behavior of shared lookups with the lookup_shared sysctl
   which has its default behavior set via the LOOKUP_SHARED option.
This commit is contained in:
jeff 2005-04-03 23:50:20 +00:00
parent b8a893bbd4
commit d9338897d1
1 changed files with 16 additions and 8 deletions
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24
sys/kern/vfs_lookup.c
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@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$");
#include "opt_ktrace.h"
#include "opt_mac.h"
#include "opt_vfs.h"
#include <sys/param.h>
#include <sys/systm.h>
@ -52,6 +53,7 @@ __FBSDID("$FreeBSD$");
#include <sys/filedesc.h>
#include <sys/proc.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
@ -75,6 +77,14 @@ nameiinit(void *dummy __unused)
}
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL)
#ifdef LOOKUP_SHARED
static int lookup_shared = 1;
#else
static int lookup_shared = 0;
#endif
SYSCTL_INT(_vfs, OID_AUTO, lookup_shared, CTLFLAG_RW, &lookup_shared, 0,
"Enables/Disables shared locks for path name translation");
/*
* Convert a pathname into a pointer to a locked inode.
*
@ -117,9 +127,8 @@ namei(ndp)
("namei: nameiop contaminated with flags"));
KASSERT((cnp->cn_flags & OPMASK) == 0,
("namei: flags contaminated with nameiops"));
#ifndef LOOKUP_SHARED
cnp->cn_flags &= ~LOCKSHARED;
#endif
if (!lookup_shared)
cnp->cn_flags &= ~LOCKSHARED;
fdp = p->p_fd;
/*
@ -362,15 +371,14 @@ lookup(ndp)
rdonly = cnp->cn_flags & RDONLY;
cnp->cn_flags &= ~ISSYMLINK;
ndp->ni_dvp = NULL;
#ifdef LOOKUP_SHARED
/*
* We use shared locks until we hit the parent of the last cn then
* we adjust based on the requesting flags.
*/
cnp->cn_lkflags = LK_SHARED;
#else
cnp->cn_lkflags = LK_EXCLUSIVE;
#endif
if (lookup_shared)
cnp->cn_lkflags = LK_SHARED;
else
cnp->cn_lkflags = LK_EXCLUSIVE;
dp = ndp->ni_startdir;
ndp->ni_startdir = NULLVP;
vn_lock(dp, cnp->cn_lkflags | LK_RETRY, td);