fs/9p: Add access = client option to opt in acl evaluation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 77 insertions, 1 deletions

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 8b3c54a4958c..12d602351dbe 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -22,6 +22,7 @@
 #include "xattr.h"
 #include "acl.h"
 #include "v9fs_vfs.h"
+#include "v9fs.h"
 
 static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
 {
@@ -55,7 +56,14 @@ int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
 {
         int retval = 0;
         struct posix_acl *pacl, *dacl;
+        struct v9fs_session_info *v9ses;
 
+        v9ses = v9fs_inode2v9ses(inode);
+        if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
+                set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
+                set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
+                return 0;
+        }
         /* get the default/access acl values and cache them */
         dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
         pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
@@ -85,7 +93,18 @@ static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
 
 int v9fs_check_acl(struct inode *inode, int mask)
 {
-        struct posix_acl *acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
+        struct posix_acl *acl;
+        struct v9fs_session_info *v9ses;
+
+        v9ses = v9fs_inode2v9ses(inode);
+        if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
+                /*
+                 * On access = client mode get the acl
+                 * values from the server
+                 */
+                return 0;
+        }
+        acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
 
         if (IS_ERR(acl))
                 return PTR_ERR(acl);
@@ -204,15 +223,41 @@ cleanup:
 
 }
 
+static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
+                               void *buffer, size_t size, int type)
+{
+        char *full_name;
+
+        switch (type) {
+        case ACL_TYPE_ACCESS:
+                full_name =  POSIX_ACL_XATTR_ACCESS;
+                break;
+        case ACL_TYPE_DEFAULT:
+                full_name = POSIX_ACL_XATTR_DEFAULT;
+                break;
+        default:
+                BUG();
+        }
+        return v9fs_xattr_get(dentry, full_name, buffer, size);
+}
+
 static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
                               void *buffer, size_t size, int type)
 {
+        struct v9fs_session_info *v9ses;
         struct posix_acl *acl;
         int error;
 
         if (strcmp(name, "") != 0)
                 return -EINVAL;
 
+        v9ses = v9fs_inode2v9ses(dentry->d_inode);
+        /*
+         * We allow set/get/list of acl when access=client is not specified
+         */
+        if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+                return v9fs_remote_get_acl(dentry, name, buffer, size, type);
+
         acl = v9fs_get_cached_acl(dentry->d_inode, type);
         if (IS_ERR(acl))
                 return PTR_ERR(acl);
@@ -224,16 +269,47 @@ static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
         return error;
 }
 
+static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
+                              const void *value, size_t size,
+                              int flags, int type)
+{
+        char *full_name;
+
+        switch (type) {
+        case ACL_TYPE_ACCESS:
+                full_name =  POSIX_ACL_XATTR_ACCESS;
+                break;
+        case ACL_TYPE_DEFAULT:
+                full_name = POSIX_ACL_XATTR_DEFAULT;
+                break;
+        default:
+                BUG();
+        }
+        return v9fs_xattr_set(dentry, full_name, value, size, flags);
+}
+
+
 static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
                               const void *value, size_t size,
                               int flags, int type)
 {
         int retval;
         struct posix_acl *acl;
+        struct v9fs_session_info *v9ses;
         struct inode *inode = dentry->d_inode;
 
         if (strcmp(name, "") != 0)
                 return -EINVAL;
+
+        v9ses = v9fs_inode2v9ses(dentry->d_inode);
+        /*
+         * set the attribute on the remote. Without even looking at the
+         * xattr value. We leave it to the server to validate
+         */
+        if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+                return v9fs_remote_set_acl(dentry, name,
+                                           value, size, flags, type);
+
         if (S_ISLNK(inode->i_mode))
                 return -EOPNOTSUPP;
         if (!is_owner_or_cap(inode))