[PATCH RFC 2/4] nfsd: make nfs4_client_reclaim use an xdr_netobj instead of a fixed char array

Scott Mayhew
2018-11-06T18:35:14Z

This will allow the reclaim_str_hashtbl to store either the recovery
directory names used by the legacy client tracking code or the full
client strings used by the nfsdcld client tracking code.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
fs/nfsd/nfs4recover.c | 79 +++++++++++++++++++++++++++++++++++++------
fs/nfsd/nfs4state.c | 30 ++++++++--------
fs/nfsd/state.h | 8 ++---
3 files changed, 87 insertions(+), 30 deletions(-)

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 5188f9f70c78..b288b14273ff 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -178,6 +178,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
struct nfs4_client_reclaim *crp;
int status;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+ struct xdr_netobj name;

if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
@@ -222,9 +223,18 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
inode_unlock(d_inode(dir));
if (status == 0) {
if (nn->in_grace) {
- crp = nfs4_client_to_reclaim(dname, nn);
- if (crp)
- crp->cr_clp = clp;
+ name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+ if (name.data) {
+ name.len = HEXDIR_LEN;
+ crp = nfs4_client_to_reclaim(name, nn);
+ if (crp)
+ crp->cr_clp = clp;
+ else
+ kfree(name.data);
+ } else {
+ dprintk("%s: failed to allocate memory for name.data!\n",
+ __func__);
+ }
}
vfs_fsync(nn->rec_file, 0);
} else {
@@ -353,6 +363,7 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
char dname[HEXDIR_LEN];
int status;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+ struct xdr_netobj name;

if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
return;
@@ -376,9 +387,17 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
vfs_fsync(nn->rec_file, 0);
if (nn->in_grace) {
/* remove reclaim record */
- crp = nfsd4_find_reclaim_client(dname, nn);
- if (crp)
- nfs4_remove_reclaim_record(crp, nn);
+ name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+ if (name.data) {
+ name.len = HEXDIR_LEN;
+ crp = nfsd4_find_reclaim_client(name, nn);
+ kfree(name.data);
+ if (crp)
+ nfs4_remove_reclaim_record(crp, nn);
+ } else {
+ dprintk("%s: failed to allocate memory for name.data!\n",
+ __func__);
+ }
}
}
out_drop_write:
@@ -393,14 +412,31 @@ static int
purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
{
int status;
+ struct xdr_netobj name;

- if (nfs4_has_reclaimed_state(child->d_name.name, nn))
+ if (child->d_name.len != HEXDIR_LEN - 1) {
+ printk("%s: illegal name %pd in recovery directory\n",
+ __func__, child);
+ /* Keep trying; maybe the others are OK: */
return 0;
+ }
+ name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+ if (!name.data) {
+ dprintk("%s: failed to allocate memory for name.data!\n",
+ __func__);
+ goto out;
+ }
+ name.len = HEXDIR_LEN;
+ if (nfs4_has_reclaimed_state(name, nn))
+ goto out_free;

status = vfs_rmdir(d_inode(parent), child);
if (status)
printk("failed to remove client recovery directory %pd\n",
child);
+out_free:
+ kfree(name.data);
+out:
/* Keep trying, success or failure: */
return 0;
}
@@ -430,13 +466,24 @@ nfsd4_recdir_purge_old(struct nfsd_net *nn)
static int
load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
{
+ struct xdr_netobj name;
+
if (child->d_name.len != HEXDIR_LEN - 1) {
- printk("nfsd4: illegal name %pd in recovery directory\n",
- child);
+ printk("%s: illegal name %pd in recovery directory\n",
+ __func__, child);
/* Keep trying; maybe the others are OK: */
return 0;
}
- nfs4_client_to_reclaim(child->d_name.name, nn);
+ name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+ if (!name.data) {
+ dprintk("%s: failed to allocate memory for name.data!\n",
+ __func__);
+ goto out;
+ }
+ name.len = HEXDIR_LEN;
+ if (!nfs4_client_to_reclaim(name, nn))
+ kfree(name.data);
+out:
return 0;
}

@@ -616,6 +663,7 @@ nfsd4_check_legacy_client(struct nfs4_client *clp)
char dname[HEXDIR_LEN];
struct nfs4_client_reclaim *crp;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+ struct xdr_netobj name;

/* did we already find that this client is stable? */
if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
@@ -628,13 +676,22 @@ nfsd4_check_legacy_client(struct nfs4_client *clp)
}

/* look for it in the reclaim hashtable otherwise */
- crp = nfsd4_find_reclaim_client(dname, nn);
+ name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+ if (!name.data) {
+ dprintk("%s: failed to allocate memory for name.data!\n",
+ __func__);
+ goto out_enoent;
+ }
+ name.len = HEXDIR_LEN;
+ crp = nfsd4_find_reclaim_client(name, nn);
+ kfree(name.data);
if (crp) {
set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
crp->cr_clp = clp;
return 0;
}

+out_enoent:
return -ENOENT;
}

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f093fbe47133..777fbb0d2761 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1058,9 +1058,9 @@ static unsigned int clientid_hashval(u32 id)
return id & CLIENT_HASH_MASK;
}

-static unsigned int clientstr_hashval(const char *name)
+static unsigned int clientstr_hashval(struct xdr_netobj name)
{
- return opaque_hashval(name, 8) & CLIENT_HASH_MASK;
+ return opaque_hashval(name.data, 8) & CLIENT_HASH_MASK;
}

/*
@@ -2039,11 +2039,6 @@ compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
return memcmp(o1->data, o2->data, o1->len);
}

-static int same_name(const char *n1, const char *n2)
-{
- return 0 == memcmp(n1, n2, HEXDIR_LEN);
-}
-
static int
same_verf(nfs4_verifier *v1, nfs4_verifier *v2)
{
@@ -6449,7 +6444,7 @@ alloc_reclaim(void)
}

bool
-nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn)
+nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn)
{
struct nfs4_client_reclaim *crp;

@@ -6459,20 +6454,24 @@ nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn)

/*
* failure => all reset bets are off, nfserr_no_grace...
+ *
+ * The caller is responsible for freeing name.data if NULL is returned (it
+ * will be freed in nfs4_remove_reclaim_record in the normal case).
*/
struct nfs4_client_reclaim *
-nfs4_client_to_reclaim(const char *name, struct nfsd_net *nn)
+nfs4_client_to_reclaim(struct xdr_netobj name, struct nfsd_net *nn)
{
unsigned int strhashval;
struct nfs4_client_reclaim *crp;

- dprintk("NFSD nfs4_client_to_reclaim NAME: %.*s\n", HEXDIR_LEN, name);
+ dprintk("NFSD nfs4_client_to_reclaim NAME: %.*s\n", name.len, name.data);
crp = alloc_reclaim();
if (crp) {
strhashval = clientstr_hashval(name);
INIT_LIST_HEAD(&crp->cr_strhash);
list_add(&crp->cr_strhash, &nn->reclaim_str_hashtbl[strhashval]);
- memcpy(crp->cr_recdir, name, HEXDIR_LEN);
+ crp->cr_name.data = name.data;
+ crp->cr_name.len = name.len;
crp->cr_clp = NULL;
nn->reclaim_str_hashtbl_size++;
}
@@ -6483,6 +6482,7 @@ void
nfs4_remove_reclaim_record(struct nfs4_client_reclaim *crp, struct nfsd_net *nn)
{
list_del(&crp->cr_strhash);
+ kfree(crp->cr_name.data);
kfree(crp);
nn->reclaim_str_hashtbl_size--;
}
@@ -6506,16 +6506,16 @@ nfs4_release_reclaim(struct nfsd_net *nn)
/*
* called from OPEN, CLAIM_PREVIOUS with a new clientid. */
struct nfs4_client_reclaim *
-nfsd4_find_reclaim_client(const char *recdir, struct nfsd_net *nn)
+nfsd4_find_reclaim_client(struct xdr_netobj name, struct nfsd_net *nn)
{
unsigned int strhashval;
struct nfs4_client_reclaim *crp = NULL;

- dprintk("NFSD: nfs4_find_reclaim_client for recdir %s\n", recdir);
+ dprintk("NFSD: nfs4_find_reclaim_client for name %.*s\n", name.len, name.data);

- strhashval = clientstr_hashval(recdir);
+ strhashval = clientstr_hashval(name);
list_for_each_entry(crp, &nn->reclaim_str_hashtbl[strhashval], cr_strhash) {
- if (same_name(crp->cr_recdir, recdir)) {
+ if (compare_blob(&crp->cr_name, &name) == 0) {
return crp;
}
}
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 6aacb325b6a0..95dd298c4620 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -367,7 +367,7 @@ struct nfs4_client {
struct nfs4_client_reclaim {
struct list_head cr_strhash; /* hash by cr_name */
struct nfs4_client *cr_clp; /* pointer to associated clp */
- char cr_recdir[HEXDIR_LEN]; /* recover dir */
+ struct xdr_netobj cr_name; /* recovery dir name */
};

/* A reasonable value for REPLAY_ISIZE was estimated as follows:
@@ -619,7 +619,7 @@ void nfs4_put_stid(struct nfs4_stid *s);
void nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid);
void nfs4_remove_reclaim_record(struct nfs4_client_reclaim *, struct nfsd_net *);
extern void nfs4_release_reclaim(struct nfsd_net *);
-extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(const char *recdir,
+extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(struct xdr_netobj name,
struct nfsd_net *nn);
extern __be32 nfs4_check_open_reclaim(clientid_t *clid,
struct nfsd4_compound_state *cstate, struct nfsd_net *nn);
@@ -634,9 +634,9 @@ extern void nfsd4_destroy_callback_queue(void);
extern void nfsd4_shutdown_callback(struct nfs4_client *);
extern void nfsd4_shutdown_copy(struct nfs4_client *clp);
extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp);
-extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name,
+extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name,
struct nfsd_net *nn);
-extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn);
+extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn);

struct nfs4_file *find_file(struct knfsd_fh *fh);
void put_nfs4_file(struct nfs4_file *fi);
--
2.17.1