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Beat vnode locking in the NFS server code into submission. This change

Browse Source 
is not pretty, but it fixes the code so that it no longer violates the
vnode locking rules in the VFS API and doesn't trip any of the locking
assertions enabled by the DEBUG_VFS_LOCKS kernel configuration option.
There is one report that this patch fixed a "locking against myself"
panic on an NFS server that was tripped by a diskless client.

Approved by:	re (scottl)
This commit is contained in:
Don Lewis 2003-05-25 06:17:33 +00:00
parent a35e7eaa1a
commit 263c8abeb9
3 changed files with 203 additions and 114 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/nfsserver/nfs.h
View File

@ -332,7 +332,8 @@ void nfsm_srvpostopattr(struct nfsrv_descript *, int, struct vattr *,
int netaddr_match(int, union nethostaddr *, struct sockaddr *);
int nfs_namei(struct nameidata *, fhandle_t *, int,
struct nfssvc_sock *, struct sockaddr *, struct mbuf **,
caddr_t *, struct vnode **, struct thread *, int);
caddr_t *, struct vnode **, int, struct vattr *, int *,
struct thread *, int);
void nfsm_adj(struct mbuf *, int, int);
int nfsm_mbuftouio(struct mbuf **, struct uio *, int, caddr_t *);
void nfsrv_initcache(void);

298
sys/nfsserver/nfs_serv.c
View File

@ -467,7 +467,7 @@ nfsrv_lookup(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nd.ni_cnd.cn_nameiop = LOOKUP;
nd.ni_cnd.cn_flags = LOCKLEAF | SAVESTART;
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, pubflag);
&dirp, v3, &dirattr, &dirattr_ret, td, pubflag);
/*
* namei failure, only dirp to cleanup. Clear out garbarge from
@ -476,9 +476,6 @@ nfsrv_lookup(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
if (error) {
if (dirp) {
if (v3)
dirattr_ret = VOP_GETATTR(dirp, &dirattr, cred,
td);
vrele(dirp);
dirp = NULL;
}
@ -551,9 +548,6 @@ nfsrv_lookup(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
}
if (dirp) {
if (v3)
dirattr_ret = VOP_GETATTR(dirp, &dirattr, cred,
td);
vrele(dirp);
dirp = NULL;
}
@ -1630,15 +1624,10 @@ nfsrv_create(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
* prior to calling nfsm_reply ( which might goto nfsmout ).
*/
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error) {
nfsm_reply(NFSX_WCCDATA(v3));
@ -1809,9 +1798,25 @@ nfsrv_create(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
if (exclusive_flag && !error &&
bcmp(cverf, (caddr_t)&vap->va_atime, NFSX_V3CREATEVERF))
error = EEXIST;
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
vrele(dirp);
dirp = NULL;
if (dirp == nd.ni_dvp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
else {
/* Drop the other locks to avoid deadlock. */
if (nd.ni_dvp) {
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
}
if (nd.ni_vp)
vput(nd.ni_vp);
nd.ni_dvp = NULL;
nd.ni_vp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
}
ereply:
nfsm_reply(NFSX_SRVFH(v3) + NFSX_FATTR(v3) + NFSX_WCCDATA(v3));
@ -1906,9 +1911,7 @@ nfsrv_mknod(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
*/
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp)
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred, td);
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (error) {
nfsm_reply(NFSX_WCCDATA(1));
nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
@ -2006,10 +2009,10 @@ nfsrv_mknod(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
vp = NULL;
nd.ni_vp = NULL;
}
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
if (dirp) {
vrele(dirp);
dirp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
ereply:
nfsm_reply(NFSX_SRVFH(1) + NFSX_POSTOPATTR(1) + NFSX_WCCDATA(1));
@ -2085,15 +2088,10 @@ nfsrv_remove(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nd.ni_cnd.cn_nameiop = DELETE;
nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error == 0) {
if (nd.ni_vp->v_type == VDIR) {
@ -2114,7 +2112,25 @@ nfsrv_remove(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
}
}
if (dirp && v3) {
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
if (dirp == nd.ni_dvp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
else {
/* Drop the other locks to avoid deadlock. */
if (nd.ni_dvp) {
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
}
if (nd.ni_vp)
vput(nd.ni_vp);
nd.ni_dvp = NULL;
nd.ni_vp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
vrele(dirp);
dirp = NULL;
}
@ -2200,15 +2216,10 @@ nfsrv_rename(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
fromnd.ni_cnd.cn_nameiop = DELETE;
fromnd.ni_cnd.cn_flags = WANTPARENT | SAVESTART;
error = nfs_namei(&fromnd, ffhp, len, slp, nam, &md,
&dpos, &fdirp, td, FALSE);
if (fdirp) {
if (v3) {
fdirfor_ret = VOP_GETATTR(fdirp, &fdirfor, cred,
td);
} else {
vrele(fdirp);
fdirp = NULL;
}
&dpos, &fdirp, v3, &fdirfor, &fdirfor_ret, td, FALSE);
if (fdirp && !v3) {
vrele(fdirp);
fdirp = NULL;
}
if (error) {
nfsm_reply(2 * NFSX_WCCDATA(v3));
@ -2227,15 +2238,10 @@ nfsrv_rename(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
tond.ni_cnd.cn_nameiop = RENAME;
tond.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF | NOCACHE | SAVESTART;
error = nfs_namei(&tond, tfhp, len2, slp, nam, &md,
&dpos, &tdirp, td, FALSE);
if (tdirp) {
if (v3) {
tdirfor_ret = VOP_GETATTR(tdirp, &tdirfor, cred,
td);
} else {
vrele(tdirp);
tdirp = NULL;
}
&dpos, &tdirp, v3, &tdirfor, &tdirfor_ret, td, FALSE);
if (tdirp && !v3) {
vrele(tdirp);
tdirp = NULL;
}
if (error)
goto out1;
@ -2318,12 +2324,30 @@ nfsrv_rename(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
/* fall through */
out1:
if (fdirp)
fdiraft_ret = VOP_GETATTR(fdirp, &fdiraft, cred, td);
if (tdirp)
tdiraft_ret = VOP_GETATTR(tdirp, &tdiraft, cred, td);
nfsm_reply(2 * NFSX_WCCDATA(v3));
if (v3) {
/* Release existing locks to prevent deadlock. */
if (tond.ni_dvp) {
if (tond.ni_dvp == tond.ni_vp)
vrele(tond.ni_dvp);
else
vput(tond.ni_dvp);
}
if (tond.ni_vp)
vput(tond.ni_vp);
tond.ni_dvp = NULL;
tond.ni_vp = NULL;
if (fdirp) {
vn_lock(fdirp, LK_EXCLUSIVE | LK_RETRY, td);
fdiraft_ret = VOP_GETATTR(fdirp, &fdiraft, cred, td);
VOP_UNLOCK(fdirp, 0, td);
}
if (tdirp) {
vn_lock(tdirp, LK_EXCLUSIVE | LK_RETRY, td);
tdiraft_ret = VOP_GETATTR(tdirp, &tdiraft, cred, td);
VOP_UNLOCK(tdirp, 0, td);
}
nfsm_srvwcc_data(fdirfor_ret, &fdirfor, fdiraft_ret, &fdiraft);
nfsm_srvwcc_data(tdirfor_ret, &tdirfor, tdiraft_ret, &tdiraft);
}
@ -2407,7 +2431,7 @@ nfsrv_link(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nfsm_srvmtofh(dfhp);
nfsm_srvnamesiz(len);
error = nfsrv_fhtovp(fhp, FALSE, &vp, cred, slp, nam, &rdonly, TRUE);
error = nfsrv_fhtovp(fhp, TRUE, &vp, cred, slp, nam, &rdonly, TRUE);
if (error) {
nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_WCCDATA(v3));
if (v3) {
@ -2418,47 +2442,71 @@ nfsrv_link(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
error = 0;
goto nfsmout;
}
if (v3)
getret = VOP_GETATTR(vp, &at, cred, td);
if (vp->v_type == VDIR) {
error = EPERM; /* POSIX */
goto out1;
}
VOP_UNLOCK(vp, 0, td);
nd.ni_cnd.cn_cred = cred;
nd.ni_cnd.cn_nameiop = CREATE;
nd.ni_cnd.cn_flags = LOCKPARENT;
error = nfs_namei(&nd, dfhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error) {
vrele(vp);
vp = NULL;
goto out2;
}
if (error)
goto out1;
xp = nd.ni_vp;
if (xp != NULL) {
error = EEXIST;
goto out;
vrele(vp);
vp = NULL;
goto out2;
}
xp = nd.ni_dvp;
if (vp->v_mount != xp->v_mount)
if (vp->v_mount != xp->v_mount) {
error = EXDEV;
out:
if (!error) {
error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
NDFREE(&nd, NDF_ONLY_PNBUF);
vrele(vp);
vp = NULL;
goto out2;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
NDFREE(&nd, NDF_ONLY_PNBUF);
/* fall through */
out1:
if (v3)
getret = VOP_GETATTR(vp, &at, cred, td);
if (dirp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
out2:
if (dirp) {
if (dirp == nd.ni_dvp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
else {
/* Release existing locks to prevent deadlock. */
if (nd.ni_dvp) {
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
}
if (nd.ni_vp)
vrele(nd.ni_vp);
nd.ni_dvp = NULL;
nd.ni_vp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
}
ereply:
nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_WCCDATA(v3));
if (v3) {
@ -2473,7 +2521,7 @@ nfsrv_link(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
if (dirp)
vrele(dirp);
if (vp)
vrele(vp);
vput(vp);
if (nd.ni_dvp) {
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
@ -2534,15 +2582,10 @@ nfsrv_symlink(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nd.ni_cnd.cn_nameiop = CREATE;
nd.ni_cnd.cn_flags = LOCKPARENT | SAVESTART;
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error)
goto out;
@ -2630,9 +2673,9 @@ nfsrv_symlink(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
pathcp = NULL;
}
if (dirp) {
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
vrele(dirp);
dirp = NULL;
VOP_UNLOCK(dirp, 0, td);
}
if (nd.ni_startdir) {
vrele(nd.ni_startdir);
@ -2719,15 +2762,10 @@ nfsrv_mkdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nd.ni_cnd.cn_flags = LOCKPARENT;
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error) {
nfsm_reply(NFSX_WCCDATA(v3));
@ -2778,8 +2816,31 @@ nfsrv_mkdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
error = VOP_GETATTR(nd.ni_vp, vap, cred, td);
}
out:
if (dirp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
if (dirp) {
if (dirp == nd.ni_dvp) {
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
} else {
/* Release existing locks to prevent deadlock. */
if (nd.ni_dvp) {
NDFREE(&nd, NDF_ONLY_PNBUF);
if (nd.ni_dvp == nd.ni_vp && vpexcl)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
}
if (nd.ni_vp) {
if (vpexcl)
vput(nd.ni_vp);
else
vrele(nd.ni_vp);
}
nd.ni_dvp = NULL;
nd.ni_vp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
}
nfsm_reply(NFSX_SRVFH(v3) + NFSX_POSTOPATTR(v3) + NFSX_WCCDATA(v3));
if (v3) {
if (!error) {
@ -2859,15 +2920,10 @@ nfsrv_rmdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
nd.ni_cnd.cn_nameiop = DELETE;
nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
error = nfs_namei(&nd, fhp, len, slp, nam, &md, &dpos,
&dirp, td, FALSE);
if (dirp) {
if (v3) {
dirfor_ret = VOP_GETATTR(dirp, &dirfor, cred,
td);
} else {
vrele(dirp);
dirp = NULL;
}
&dirp, v3, &dirfor, &dirfor_ret, td, FALSE);
if (dirp && !v3) {
vrele(dirp);
dirp = NULL;
}
if (error) {
nfsm_reply(NFSX_WCCDATA(v3));
@ -2902,8 +2958,26 @@ nfsrv_rmdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
NDFREE(&nd, NDF_ONLY_PNBUF);
if (dirp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
if (dirp) {
if (dirp == nd.ni_dvp)
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
else {
/* Release existing locks to prevent deadlock. */
if (nd.ni_dvp) {
if (nd.ni_dvp == nd.ni_vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
}
if (nd.ni_vp)
vput(nd.ni_vp);
nd.ni_dvp = NULL;
nd.ni_vp = NULL;
vn_lock(dirp, LK_EXCLUSIVE | LK_RETRY, td);
diraft_ret = VOP_GETATTR(dirp, &diraft, cred, td);
VOP_UNLOCK(dirp, 0, td);
}
}
nfsm_reply(NFSX_WCCDATA(v3));
error = 0;
if (v3)

16
sys/nfsserver/nfs_srvsubs.c
View File

@ -592,7 +592,8 @@ MODULE_VERSION(nfsserver, 1);
int
nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
struct nfssvc_sock *slp, struct sockaddr *nam, struct mbuf **mdp,
caddr_t *dposp, struct vnode **retdirp, struct thread *td, int pubflag)
caddr_t *dposp, struct vnode **retdirp, int v3, struct vattr *retdirattrp,
int *retdirattr_retp, struct thread *td, int pubflag)
{
int i, rem;
struct mbuf *md;
@ -602,6 +603,7 @@ nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
struct vnode *dp;
int error, rdonly, linklen;
struct componentname *cnp = &ndp->ni_cnd;
int lockleaf = (cnp->cn_flags & LOCKLEAF) != 0;
*retdirp = NULL;
cnp->cn_flags |= NOMACCHECK;
@ -664,6 +666,12 @@ nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
* to the returned pointer
*/
*retdirp = dp;
if (v3) {
vn_lock(dp, LK_EXCLUSIVE | LK_RETRY, td);
*retdirattr_retp = VOP_GETATTR(dp, retdirattrp,
ndp->ni_cnd.cn_cred, td);
VOP_UNLOCK(dp, 0, td);
}
if (pubflag) {
/*
@ -736,6 +744,8 @@ nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
VREF(dp);
ndp->ni_startdir = dp;
if (!lockleaf)
cnp->cn_flags |= LOCKLEAF;
for (;;) {
cnp->cn_nameptr = cnp->cn_pnbuf;
/*
@ -761,6 +771,8 @@ nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
cnp->cn_flags |= HASBUF;
else
uma_zfree(namei_zone, cnp->cn_pnbuf);
if (ndp->ni_vp && !lockleaf)
VOP_UNLOCK(ndp->ni_vp, 0, td);
break;
}
@ -840,6 +852,8 @@ nfs_namei(struct nameidata *ndp, fhandle_t *fhp, int len,
ndp->ni_startdir = ndp->ni_dvp;
ndp->ni_dvp = NULL;
}
if (!lockleaf)
cnp->cn_flags &= ~LOCKLEAF;
/*
* nfs_namei() guarentees that fields will not contain garbage