NFSv4: Add ACCESS operation to OPEN compound

The OPEN operation has no way to differentiate an open for read and an
open for execution - both look like read to the server. This allowed
users to read files that didn't have READ access but did have EXEC access,
which is obviously wrong.

This patch adds an ACCESS call to the OPEN compound to handle the
difference between OPENs for reading and execution.  Since we're going
through the trouble of calling ACCESS, we check all possible access bits
and cache the results hopefully avoiding an ACCESS call in the future.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 383f3313f053..334a2f5f6bf1 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -360,6 +360,8 @@ extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
+extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
 extern int nfs_permission(struct inode *, int);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 5da789fdf25b..655490dae953 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -334,6 +334,7 @@ struct nfs_openargs {
         struct nfs_seqid *      seqid;
         int                     open_flags;
         fmode_t                 fmode;
+        u32                     access;
         __u64                   clientid;
         struct stateowner_id    id;
         union {
@@ -368,6 +369,8 @@ struct nfs_openres {
         struct nfs4_string      *owner;
         struct nfs4_string      *group_owner;
         struct nfs4_sequence_res        seq_res;
+        __u32                   access_supported;
+        __u32                   access_result;
 };
 
 /*