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- cache_lookup() now locks the new vnode for us to prevent some races.

Browse Source 
Remove redundant code.

Sponsored by:	Isilon Systems, Inc.
This commit is contained in:
Jeff Roberson 2005-03-29 13:00:37 +00:00
parent 5280e61f2f
commit 5c5e51fd9a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=144297
3 changed files with 73 additions and 134 deletions
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94
sys/fs/smbfs/smbfs_vnops.c
View File

@ -1120,64 +1120,44 @@ smbfs_lookup(ap)
if (error) { /* name was found */
struct vattr vattr;
vhold(*vpp);
vp = *vpp;
if (dvp == vp) { /* lookup on current */
vref(vp);
error = 0;
SMBVDEBUG("cached '.'\n");
} else if (flags & ISDOTDOT) {
VOP_UNLOCK(dvp, 0, td); /* unlock parent */
error = vget(vp, LK_EXCLUSIVE, td);
if (error)
if (vn_lock(dvp, LK_EXCLUSIVE, td))
panic("smbfs_lookup: Can't "
"relock directory.");
} else
error = vget(vp, LK_EXCLUSIVE, td);
if (!error) {
killit = 0;
error = VOP_GETATTR(vp, &vattr, cnp->cn_cred, td);
/*
* If the file type on the server is inconsistent
* with what it was when we created the vnode,
* kill the bogus vnode now and fall through to
* the code below to create a new one with the
* right type.
*/
if (error == 0 &&
((vp->v_type == VDIR &&
(VTOSMB(vp)->n_dosattr & SMB_FA_DIR) == 0) ||
(vp->v_type == VREG &&
(VTOSMB(vp)->n_dosattr & SMB_FA_DIR) != 0)))
killit = 1;
else if (error == 0
/* && vattr.va_ctime.tv_sec == VTOSMB(vp)->n_ctime*/) {
if (nameiop != LOOKUP && islastcn)
cnp->cn_flags |= SAVENAME;
SMBVDEBUG("use cached vnode\n");
vdrop(vp);
return (0);
}
cache_purge(vp);
/*
* XXX This is not quite right, if '.' is
* inconsistent, we really need to start the lookup
* all over again. Hopefully there is some other
* guarantee that prevents this case from happening.
*/
if (killit && vp != dvp)
vgone(vp);
if (vp != dvp)
vput(vp);
else
vrele(vp);
if (flags & ISDOTDOT)
if (vn_lock(dvp, LK_EXCLUSIVE, td))
panic("smbfs_lookup: Can't "
"relock directory.");
killit = 0;
error = VOP_GETATTR(vp, &vattr, cnp->cn_cred, td);
/*
* If the file type on the server is inconsistent
* with what it was when we created the vnode,
* kill the bogus vnode now and fall through to
* the code below to create a new one with the
* right type.
*/
if (error == 0 &&
((vp->v_type == VDIR &&
(VTOSMB(vp)->n_dosattr & SMB_FA_DIR) == 0) ||
(vp->v_type == VREG &&
(VTOSMB(vp)->n_dosattr & SMB_FA_DIR) != 0)))
killit = 1;
else if (error == 0
/* && vattr.va_ctime.tv_sec == VTOSMB(vp)->n_ctime*/) {
if (nameiop != LOOKUP && islastcn)
cnp->cn_flags |= SAVENAME;
SMBVDEBUG("use cached vnode\n");
return (0);
}
vdrop(vp);
cache_purge(vp);
/*
* XXX This is not quite right, if '.' is
* inconsistent, we really need to start the lookup
* all over again. Hopefully there is some other
* guarantee that prevents this case from happening.
*/
if (killit && vp != dvp)
vgone(vp);
if (vp != dvp)
vput(vp);
else
vrele(vp);
if (flags & ISDOTDOT)
if (vn_lock(dvp, LK_EXCLUSIVE, td))
panic("smbfs_lookup: Can't relock directory.");
*vpp = NULLVP;
}
/*

57
sys/nfs4client/nfs4_vnops.c
View File

@ -956,50 +956,29 @@ nfs4_lookup(struct vop_lookup_args *ap)
isdot = cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.';
if ((error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td)) != 0) {
*vpp = NULLVP;
return (error);
}
if ((error = cache_lookup(dvp, vpp, cnp)) && error != ENOENT) {
struct vattr vattr;
if ((error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td)) != 0) {
*vpp = NULLVP;
return (error);
}
vhold(*vpp);
newvp = *vpp;
/*
* See the comment starting `Step through' in ufs/ufs_lookup.c
* for an explanation of the locking protocol
*/
if (dvp == newvp) {
VREF(newvp);
error = 0;
} else if (flags & ISDOTDOT) {
VOP_UNLOCK(dvp, 0, td);
error = vget(newvp, LK_EXCLUSIVE, td);
if (error)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
} else
error = vget(newvp, LK_EXCLUSIVE, td);
if (!error) {
if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, td)
&& vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime) {
nfsstats.lookupcache_hits++;
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
cnp->cn_flags |= SAVENAME;
vdrop(newvp);
return (0);
}
cache_purge(newvp);
if (newvp != dvp)
vput(newvp);
else
vrele(newvp);
if (flags & ISDOTDOT)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, td)
&& vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime) {
nfsstats.lookupcache_hits++;
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
cnp->cn_flags |= SAVENAME;
return (0);
}
vdrop(newvp);
*vpp = NULLVP;
cache_purge(newvp);
if (newvp != dvp)
vput(newvp);
else
vrele(newvp);
if (flags & ISDOTDOT)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
}
error = 0;

56
sys/nfsclient/nfs_vnops.c
View File

@ -789,49 +789,29 @@ nfs_lookup(struct vop_lookup_args *ap)
wantparent = flags & (LOCKPARENT|WANTPARENT);
nmp = VFSTONFS(dvp->v_mount);
np = VTONFS(dvp);
if ((error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td)) != 0) {
*vpp = NULLVP;
return (error);
}
if ((error = cache_lookup(dvp, vpp, cnp)) && error != ENOENT) {
struct vattr vattr;
if ((error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td)) != 0) {
*vpp = NULLVP;
return (error);
}
vhold(*vpp);
newvp = *vpp;
/*
* See the comment starting `Step through' in ufs/ufs_lookup.c
* for an explanation of the locking protocol
*/
if (dvp == newvp) {
VREF(newvp);
error = 0;
} else if (flags & ISDOTDOT) {
VOP_UNLOCK(dvp, 0, td);
error = vget(newvp, LK_EXCLUSIVE, td);
if (error)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
} else
error = vget(newvp, LK_EXCLUSIVE, td);
if (!error) {
if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, td)
&& vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime) {
nfsstats.lookupcache_hits++;
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
cnp->cn_flags |= SAVENAME;
vdrop(newvp);
return (0);
}
cache_purge(newvp);
if (dvp != newvp)
vput(newvp);
else
vrele(newvp);
if (flags & ISDOTDOT)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, td)
&& vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime) {
nfsstats.lookupcache_hits++;
if (cnp->cn_nameiop != LOOKUP &&
(flags & ISLASTCN))
cnp->cn_flags |= SAVENAME;
return (0);
}
vdrop(newvp);
cache_purge(newvp);
if (dvp != newvp)
vput(newvp);
else
vrele(newvp);
if (flags & ISDOTDOT)
vn_lock(dvp, LK_EXCLUSIVE|LK_RETRY, td);
*vpp = NULLVP;
}
error = 0;