NFS: pass cred explicitly for access tests
Storing the 'struct cred *' in nfs_access_entry is problematic.
An active 'cred' can keep a 'struct key *' active, and a quota is
imposed on the number of such keys that a user can maintain.
Cached 'nfs_access_entry' structs have indefinite lifetime, and having
these keep 'struct key's alive imposes on that quota.
So a future patch will remove the ->cred ref from nfs_access_entry.
To prepare, change various functions to not assume there is a 'cred' in
the nfs_access_entry, but to pass the cred around explicitly.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8487a6d..a34351c 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2758,7 +2758,9 @@ int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
}
EXPORT_SYMBOL_GPL(nfs_access_get_cached);
-static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
+static void nfs_access_add_rbtree(struct inode *inode,
+ struct nfs_access_entry *set,
+ const struct cred *cred)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct rb_root *root_node = &nfsi->access_cache;
@@ -2771,7 +2773,7 @@ static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *
while (*p != NULL) {
parent = *p;
entry = rb_entry(parent, struct nfs_access_entry, rb_node);
- cmp = cred_fscmp(set->cred, entry->cred);
+ cmp = cred_fscmp(cred, entry->cred);
if (cmp < 0)
p = &parent->rb_left;
@@ -2793,13 +2795,14 @@ static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *
nfs_access_free_entry(entry);
}
-void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
+void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set,
+ const struct cred *cred)
{
struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
if (cache == NULL)
return;
RB_CLEAR_NODE(&cache->rb_node);
- cache->cred = get_cred(set->cred);
+ cache->cred = get_cred(cred);
cache->mask = set->mask;
/* The above field assignments must be visible
@@ -2807,7 +2810,7 @@ void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
* use rcu_assign_pointer, so just force the memory barrier.
*/
smp_wmb();
- nfs_access_add_rbtree(inode, cache);
+ nfs_access_add_rbtree(inode, cache, cred);
/* Update accounting */
smp_mb__before_atomic();
@@ -2893,7 +2896,7 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
else
cache.mask |= NFS_ACCESS_EXECUTE;
cache.cred = cred;
- status = NFS_PROTO(inode)->access(inode, &cache);
+ status = NFS_PROTO(inode)->access(inode, &cache, cred);
if (status != 0) {
if (status == -ESTALE) {
if (!S_ISDIR(inode->i_mode))
@@ -2903,7 +2906,7 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
}
goto out;
}
- nfs_access_add_cache(inode, &cache);
+ nfs_access_add_cache(inode, &cache, cred);
out_cached:
cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 7100514..1597eef 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -220,7 +220,8 @@ static int nfs3_proc_lookupp(struct inode *inode, struct nfs_fh *fhandle,
task_flags);
}
-static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry,
+ const struct cred *cred)
{
struct nfs3_accessargs arg = {
.fh = NFS_FH(inode),
@@ -231,7 +232,7 @@ static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
.rpc_proc = &nfs3_procedures[NFS3PROC_ACCESS],
.rpc_argp = &arg,
.rpc_resp = &res,
- .rpc_cred = entry->cred,
+ .rpc_cred = cred,
};
int status = -ENOMEM;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 322ff45..f02aa987 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2655,7 +2655,7 @@ static int nfs4_opendata_access(const struct cred *cred,
cache.cred = cred;
nfs_access_set_mask(&cache, opendata->o_res.access_result);
- nfs_access_add_cache(state->inode, &cache);
+ nfs_access_add_cache(state->inode, &cache, cred);
flags = NFS4_ACCESS_READ | NFS4_ACCESS_EXECUTE | NFS4_ACCESS_LOOKUP;
if ((mask & ~cache.mask & flags) == 0)
@@ -4441,7 +4441,8 @@ static int nfs4_proc_lookupp(struct inode *inode, struct nfs_fh *fhandle,
return err;
}
-static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry,
+ const struct cred *cred)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs4_accessargs args = {
@@ -4455,7 +4456,7 @@ static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry
.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ACCESS],
.rpc_argp = &args,
.rpc_resp = &res,
- .rpc_cred = entry->cred,
+ .rpc_cred = cred,
};
int status = 0;
@@ -4475,14 +4476,15 @@ static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry
return status;
}
-static int nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+static int nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry,
+ const struct cred *cred)
{
struct nfs4_exception exception = {
.interruptible = true,
};
int err;
do {
- err = _nfs4_proc_access(inode, entry);
+ err = _nfs4_proc_access(inode, entry, cred);
trace_nfs4_access(inode, err);
err = nfs4_handle_exception(NFS_SERVER(inode), err,
&exception);