Update nfs4_get_vfs_file and nfs4_upgrade_open to handle share
reservation conflict with courtesy client.
If share/access check fails with share denied then check if the
the conflict was caused by courtesy clients. If that's the case
then set CLIENT_EXPIRED flag to expire the courtesy clients and
allow nfs4_get_vfs_file to continue. Client with CLIENT_EXPIRED
is expired by the laundromat.
Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 91 insertions(+), 8 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 2beb0972de88..b16f689f34c3 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4973,9 +4973,75 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
return nfsd_setattr(rqstp, fh, &iattr, 0, (time64_t)0);
}
+static bool
+nfs4_check_access_deny_bmap(struct nfs4_ol_stateid *stp, u32 access,
+ bool share_access)
+{
+ if (share_access) {
+ if (!stp->st_deny_bmap)
+ return false;
+
+ if ((stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_BOTH)) ||
+ (access & NFS4_SHARE_ACCESS_READ &&
+ stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_READ)) ||
+ (access & NFS4_SHARE_ACCESS_WRITE &&
+ stp->st_deny_bmap & (1 << NFS4_SHARE_DENY_WRITE))) {
+ return true;
+ }
+ return false;
+ }
+ if ((access & NFS4_SHARE_DENY_BOTH) ||
+ (access & NFS4_SHARE_DENY_READ &&
+ stp->st_access_bmap & (1 << NFS4_SHARE_ACCESS_READ)) ||
+ (access & NFS4_SHARE_DENY_WRITE &&
+ stp->st_access_bmap & (1 << NFS4_SHARE_ACCESS_WRITE))) {
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Check whether courtesy clients have conflicting access
+ *
+ * access: is op_share_access if share_access is true.
+ * Check if access mode, op_share_access, would conflict with
+ * the current deny mode of the file 'fp'.
+ * access: is op_share_deny if share_access is false.
+ * Check if the deny mode, op_share_deny, would conflict with
+ * current access of the file 'fp'.
+ * stp: skip checking this entry.
+ * new_stp: normal open, not open upgrade.
+ *
+ * Function returns:
+ * true - access/deny mode conflict with normal client.
+ * false - no conflict or conflict with courtesy client(s) is resolved.
+ */
+static bool
+nfs4_resolve_deny_conflicts_locked(struct nfs4_file *fp, bool new_stp,
+ struct nfs4_ol_stateid *stp, u32 access, bool share_access)
+{
+ struct nfs4_ol_stateid *st;
+ struct nfs4_client *clp;
+ bool conflict = false;
+
+ lockdep_assert_held(&fp->fi_lock);
+ list_for_each_entry(st, &fp->fi_stateids, st_perfile) {
+ if (st->st_openstp || (st == stp && new_stp) ||
+ (!nfs4_check_access_deny_bmap(st,
+ access, share_access)))
+ continue;
+ clp = st->st_stid.sc_client;
+ if (nfs4_check_and_expire_courtesy_client(clp))
+ continue;
+ conflict = true;
+ break;
+ }
+ return conflict;
+}
+
static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
- struct nfsd4_open *open)
+ struct nfsd4_open *open, bool new_stp)
{
struct nfsd_file *nf = NULL;
__be32 status;
@@ -4991,15 +5057,29 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
*/
status = nfs4_file_check_deny(fp, open->op_share_deny);
if (status != nfs_ok) {
- spin_unlock(&fp->fi_lock);
- goto out;
+ if (status != nfserr_share_denied) {
+ spin_unlock(&fp->fi_lock);
+ goto out;
+ }
+ if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
+ stp, open->op_share_deny, false)) {
+ spin_unlock(&fp->fi_lock);
+ goto out;
+ }
}
/* set access to the file */
status = nfs4_file_get_access(fp, open->op_share_access);
if (status != nfs_ok) {
- spin_unlock(&fp->fi_lock);
- goto out;
+ if (status != nfserr_share_denied) {
+ spin_unlock(&fp->fi_lock);
+ goto out;
+ }
+ if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
+ stp, open->op_share_access, true)) {
+ spin_unlock(&fp->fi_lock);
+ goto out;
+ }
}
/* Set access bits in stateid */
@@ -5050,7 +5130,7 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c
unsigned char old_deny_bmap = stp->st_deny_bmap;
if (!test_access(open->op_share_access, stp))
- return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open);
+ return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open, false);
/* test and set deny mode */
spin_lock(&fp->fi_lock);
@@ -5059,7 +5139,10 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c
set_deny(open->op_share_deny, stp);
fp->fi_share_deny |=
(open->op_share_deny & NFS4_SHARE_DENY_BOTH);
- }
+ } else if (status == nfserr_share_denied &&
+ !nfs4_resolve_deny_conflicts_locked(fp, false, stp,
+ open->op_share_deny, false))
+ status = nfs_ok;
spin_unlock(&fp->fi_lock);
if (status != nfs_ok)
@@ -5399,7 +5482,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
goto out;
}
} else {
- status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open);
+ status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open, true);
if (status) {
stp->st_stid.sc_type = NFS4_CLOSED_STID;
release_open_stateid(stp);
--
2.9.5
