git: e7474c619270 - stable/14 - nfsd: Fix close handling when vfs.nfsd.enable_locallocks=1
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Date: Sat, 12 Oct 2024 00:44:53 UTC
The branch stable/14 has been updated by rmacklem:
URL: https://cgit.FreeBSD.org/src/commit/?id=e7474c619270c5c325ce844b77eecc2dcf98147c
commit e7474c619270c5c325ce844b77eecc2dcf98147c
Author: Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2024-09-30 22:49:57 +0000
Commit: Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2024-10-12 00:43:27 +0000
nfsd: Fix close handling when vfs.nfsd.enable_locallocks=1
nfsrv_freeopen() was being called after the mutex
lock was released, making it possible for other
kernel threads to change the lists while nfsrv_freeopen()
took the nfsstateid out of the lists.
This patch moves the code around
"if (nfsrv_freeopen(stp, vp, 1 p) == 0) {"
into nfsrv_freeopen(), so that it can remove the nfsstateid
structure from all lists before unlocking the mutex.
This should avoid any race between CLOSE and other nfsd threads
updating the NFSv4 state.
The patch does not affect semantics when vfs.nfsd.enable_locallocks=0.
PR: 280978
Tested by: Matthew L. Dailey <matthew.l.dailey@dartmouth.edu>
(cherry picked from commit eb345e05ac6602eeef0c33fce9025bbc8ec44d0f)
---
sys/fs/nfsserver/nfs_nfsdstate.c | 62 +++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 32 deletions(-)
diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c
index 6b40e0f64141..6cd8c1c861ec 100644
--- a/sys/fs/nfsserver/nfs_nfsdstate.c
+++ b/sys/fs/nfsserver/nfs_nfsdstate.c
@@ -139,7 +139,7 @@ static void nfsrv_dumpaclient(struct nfsclient *clp,
struct nfsd_dumpclients *dumpp);
static void nfsrv_freeopenowner(struct nfsstate *stp, int cansleep,
NFSPROC_T *p);
-static int nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep,
+static void nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep,
NFSPROC_T *p);
static void nfsrv_freelockowner(struct nfsstate *stp, vnode_t vp, int cansleep,
NFSPROC_T *p);
@@ -1566,7 +1566,7 @@ nfsrv_freeopenowner(struct nfsstate *stp, int cansleep, NFSPROC_T *p)
while (nstp != LIST_END(&stp->ls_open)) {
tstp = nstp;
nstp = LIST_NEXT(nstp, ls_list);
- (void) nfsrv_freeopen(tstp, NULL, cansleep, p);
+ nfsrv_freeopen(tstp, NULL, cansleep, p);
}
if (stp->ls_op)
nfsrvd_derefcache(stp->ls_op);
@@ -1581,12 +1581,11 @@ nfsrv_freeopenowner(struct nfsstate *stp, int cansleep, NFSPROC_T *p)
* are no other opens on the file.
* Returns 1 if it free'd the nfslockfile, 0 otherwise.
*/
-static int
+static void
nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep, NFSPROC_T *p)
{
struct nfsstate *nstp, *tstp;
struct nfslockfile *lfp;
- int ret;
LIST_REMOVE(stp, ls_hash);
LIST_REMOVE(stp, ls_list);
@@ -1595,35 +1594,46 @@ nfsrv_freeopen(struct nfsstate *stp, vnode_t vp, int cansleep, NFSPROC_T *p)
lfp = stp->ls_lfp;
/*
* Now, free all lockowners associated with this open.
+ * Note that, if vp != NULL, nfsrv_freelockowner() will
+ * not call nfsrv_freeallnfslocks(), so it needs to be called, below.
*/
LIST_FOREACH_SAFE(tstp, &stp->ls_open, ls_list, nstp)
nfsrv_freelockowner(tstp, vp, cansleep, p);
+ if (vp != NULL) {
+ KASSERT(cansleep != 0, ("nfsrv_freeopen: cansleep == 0"));
+ mtx_assert(NFSSTATEMUTEXPTR, MA_OWNED);
+ /*
+ * Only called with vp != NULL for Close when
+ * vfs.nfsd.enable_locallocks != 0.
+ * Lock the lfp so that it will not go away and do the
+ * nfsrv_freeallnfslocks() call that was not done by
+ * nfsrv_freelockowner().
+ */
+ nfsrv_locklf(lfp);
+ NFSUNLOCKSTATE();
+ NFSVOPUNLOCK(vp);
+ nfsrv_freeallnfslocks(stp, vp, cansleep, p);
+ NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
+ NFSLOCKSTATE();
+ nfsrv_unlocklf(lfp);
+ }
+
/*
* The nfslockfile is freed here if there are no locks
* associated with the open.
* If there are locks associated with the open, the
* nfslockfile structure can be freed via nfsrv_freelockowner().
- * Acquire the state mutex to avoid races with calls to
- * nfsrv_getlockfile().
*/
- if (cansleep != 0)
- NFSLOCKSTATE();
if (lfp != NULL && LIST_EMPTY(&lfp->lf_open) &&
LIST_EMPTY(&lfp->lf_deleg) && LIST_EMPTY(&lfp->lf_lock) &&
LIST_EMPTY(&lfp->lf_locallock) && LIST_EMPTY(&lfp->lf_rollback) &&
lfp->lf_usecount == 0 &&
- (cansleep != 0 || nfsv4_testlock(&lfp->lf_locallock_lck) == 0)) {
+ nfsv4_testlock(&lfp->lf_locallock_lck) == 0)
nfsrv_freenfslockfile(lfp);
- ret = 1;
- } else
- ret = 0;
- if (cansleep != 0)
- NFSUNLOCKSTATE();
free(stp, M_NFSDSTATE);
NFSD_VNET(nfsstatsv1_p)->srvopens--;
nfsrv_openpluslock--;
- return (ret);
}
/*
@@ -1636,7 +1646,8 @@ nfsrv_freelockowner(struct nfsstate *stp, vnode_t vp, int cansleep,
LIST_REMOVE(stp, ls_hash);
LIST_REMOVE(stp, ls_list);
- nfsrv_freeallnfslocks(stp, vp, cansleep, p);
+ if (vp == NULL)
+ nfsrv_freeallnfslocks(stp, vp, cansleep, p);
if (stp->ls_op)
nfsrvd_derefcache(stp->ls_op);
free(stp, M_NFSDSTATE);
@@ -3431,7 +3442,6 @@ nfsrv_openupdate(vnode_t vp, struct nfsstate *new_stp, nfsquad_t clientid,
{
struct nfsstate *stp;
struct nfsclient *clp;
- struct nfslockfile *lfp;
u_int32_t bits;
int error = 0, gotstate = 0, len = 0;
u_char *clidp = NULL;
@@ -3526,9 +3536,7 @@ nfsrv_openupdate(vnode_t vp, struct nfsstate *new_stp, nfsquad_t clientid,
NFSBCOPY(clp->lc_id, clidp, len);
gotstate = 1;
}
- NFSUNLOCKSTATE();
} else if (new_stp->ls_flags & NFSLCK_CLOSE) {
- lfp = stp->ls_lfp;
if (retwriteaccessp != NULL) {
if ((stp->ls_flags & NFSLCK_WRITEACCESS) != 0)
*retwriteaccessp = 1;
@@ -3536,20 +3544,10 @@ nfsrv_openupdate(vnode_t vp, struct nfsstate *new_stp, nfsquad_t clientid,
*retwriteaccessp = 0;
}
if (nfsrv_dolocallocks != 0 && !LIST_EMPTY(&stp->ls_open)) {
- /* Get the lf lock */
- nfsrv_locklf(lfp);
- NFSUNLOCKSTATE();
ASSERT_VOP_ELOCKED(vp, "nfsrv_openupdate");
- NFSVOPUNLOCK(vp);
- if (nfsrv_freeopen(stp, vp, 1, p) == 0) {
- NFSLOCKSTATE();
- nfsrv_unlocklf(lfp);
- NFSUNLOCKSTATE();
- }
- NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
+ nfsrv_freeopen(stp, vp, 1, p);
} else {
- (void) nfsrv_freeopen(stp, NULL, 0, p);
- NFSUNLOCKSTATE();
+ nfsrv_freeopen(stp, NULL, 0, p);
}
} else {
/*
@@ -3567,8 +3565,8 @@ nfsrv_openupdate(vnode_t vp, struct nfsstate *new_stp, nfsquad_t clientid,
if ((nd->nd_flag & ND_NFSV41) != 0 &&
stp->ls_stateid.seqid == 0)
stp->ls_stateid.seqid = 1;
- NFSUNLOCKSTATE();
}
+ NFSUNLOCKSTATE();
/*
* If the client just confirmed its first open, write a timestamp