CRED: Wrap task credential accesses in the NCPFS filesystem

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 44 insertions, 47 deletions

diff --git a/fs/ncpfs/ioctl.c b/fs/ncpfs/ioctl.c
index 3a97c95e1ca..6d04e050c74 100644
--- a/fs/ncpfs/ioctl.c
+++ b/fs/ncpfs/ioctl.c
@@ -40,10 +40,10 @@ ncp_get_fs_info(struct ncp_server * server, struct file *file,
         struct inode *inode = file->f_path.dentry->d_inode;
         struct ncp_fs_info info;
 
-        if ((file_permission(file, MAY_WRITE) != 0)
-            && (current->uid != server->m.mounted_uid)) {
+        if (file_permission(file, MAY_WRITE) != 0
+            && current_uid() != server->m.mounted_uid)
                 return -EACCES;
-        }
+
         if (copy_from_user(&info, arg, sizeof(info)))
                 return -EFAULT;
 
@@ -70,10 +70,10 @@ ncp_get_fs_info_v2(struct ncp_server * server, struct file *file,
         struct inode *inode = file->f_path.dentry->d_inode;
         struct ncp_fs_info_v2 info2;
 
-        if ((file_permission(file, MAY_WRITE) != 0)
-            && (current->uid != server->m.mounted_uid)) {
+        if (file_permission(file, MAY_WRITE) != 0
+            && current_uid() != server->m.mounted_uid)
                 return -EACCES;
-        }
+
         if (copy_from_user(&info2, arg, sizeof(info2)))
                 return -EFAULT;
 
@@ -141,10 +141,10 @@ ncp_get_compat_fs_info_v2(struct ncp_server * server, struct file *file,
         struct inode *inode = file->f_path.dentry->d_inode;
         struct compat_ncp_fs_info_v2 info2;
 
-        if ((file_permission(file, MAY_WRITE) != 0)
-            && (current->uid != server->m.mounted_uid)) {
+        if (file_permission(file, MAY_WRITE) != 0
+            && current_uid() != server->m.mounted_uid)
                 return -EACCES;
-        }
+
         if (copy_from_user(&info2, arg, sizeof(info2)))
                 return -EFAULT;
 
@@ -270,16 +270,17 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
         struct ncp_ioctl_request request;
         char* bouncebuffer;
         void __user *argp = (void __user *)arg;
+        uid_t uid = current_uid();
 
         switch (cmd) {
 #ifdef CONFIG_COMPAT
         case NCP_IOC_NCPREQUEST_32:
 #endif
         case NCP_IOC_NCPREQUEST:
-                if ((file_permission(filp, MAY_WRITE) != 0)
-                    && (current->uid != server->m.mounted_uid)) {
+                if (file_permission(filp, MAY_WRITE) != 0
+                    && uid != server->m.mounted_uid)
                         return -EACCES;
-                }
+
 #ifdef CONFIG_COMPAT
                 if (cmd == NCP_IOC_NCPREQUEST_32) {
                         struct compat_ncp_ioctl_request request32;
@@ -356,10 +357,10 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
         case NCP_IOC_GETMOUNTUID16:
         case NCP_IOC_GETMOUNTUID32:
         case NCP_IOC_GETMOUNTUID64:
-                if ((file_permission(filp, MAY_READ) != 0)
-                        && (current->uid != server->m.mounted_uid)) {
+                if (file_permission(filp, MAY_READ) != 0
+                        && uid != server->m.mounted_uid)
                         return -EACCES;
-                }
+
                 if (cmd == NCP_IOC_GETMOUNTUID16) {
                         u16 uid;
                         SET_UID(uid, server->m.mounted_uid);
@@ -380,11 +381,10 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
                 {
                         struct ncp_setroot_ioctl sr;
 
-                        if ((file_permission(filp, MAY_READ) != 0)
-                            && (current->uid != server->m.mounted_uid))
-                        {
+                        if (file_permission(filp, MAY_READ) != 0
+                            && uid != server->m.mounted_uid)
                                 return -EACCES;
-                        }
+
                         if (server->m.mounted_vol[0]) {
                                 struct dentry* dentry = inode->i_sb->s_root;
 
@@ -408,6 +408,7 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
                                 return -EFAULT;
                         return 0;
                 }
+
         case NCP_IOC_SETROOT:
                 {
                         struct ncp_setroot_ioctl sr;
@@ -455,11 +456,10 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
 
 #ifdef CONFIG_NCPFS_PACKET_SIGNING      
         case NCP_IOC_SIGN_INIT:
-                if ((file_permission(filp, MAY_WRITE) != 0)
-                    && (current->uid != server->m.mounted_uid))
-                {
+                if (file_permission(filp, MAY_WRITE) != 0
+                    && uid != server->m.mounted_uid)
                         return -EACCES;
-                }
+
                 if (argp) {
                         if (server->sign_wanted)
                         {
@@ -478,24 +478,22 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
                 return 0;               
                 
         case NCP_IOC_SIGN_WANTED:
-                if ((file_permission(filp, MAY_READ) != 0)
-                    && (current->uid != server->m.mounted_uid))
-                {
+                if (file_permission(filp, MAY_READ) != 0
+                    && uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 
                 if (put_user(server->sign_wanted, (int __user *)argp))
                         return -EFAULT;
                 return 0;
+
         case NCP_IOC_SET_SIGN_WANTED:
                 {
                         int newstate;
 
-                        if ((file_permission(filp, MAY_WRITE) != 0)
-                            && (current->uid != server->m.mounted_uid))
-                        {
+                        if (file_permission(filp, MAY_WRITE) != 0
+                            && uid != server->m.mounted_uid)
                                 return -EACCES;
-                        }
+
                         /* get only low 8 bits... */
                         if (get_user(newstate, (unsigned char __user *)argp))
                                 return -EFAULT;
@@ -512,11 +510,10 @@ static int __ncp_ioctl(struct inode *inode, struct file *filp,
 
 #ifdef CONFIG_NCPFS_IOCTL_LOCKING
         case NCP_IOC_LOCKUNLOCK:
-                if ((file_permission(filp, MAY_WRITE) != 0)
-                    && (current->uid != server->m.mounted_uid))
-                {
+                if (file_permission(filp, MAY_WRITE) != 0
+                    && uid != server->m.mounted_uid)
                         return -EACCES;
-                }
+
                 {
                         struct ncp_lock_ioctl    rqdata;
 
@@ -585,9 +582,8 @@ outrel:
 
 #ifdef CONFIG_COMPAT
         case NCP_IOC_GETOBJECTNAME_32:
-                if (current->uid != server->m.mounted_uid) {
+                if (uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 {
                         struct compat_ncp_objectname_ioctl user;
                         size_t outl;
@@ -609,10 +605,10 @@ outrel:
                         return 0;
                 }
 #endif
+
         case NCP_IOC_GETOBJECTNAME:
-                if (current->uid != server->m.mounted_uid) {
+                if (uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 {
                         struct ncp_objectname_ioctl user;
                         size_t outl;
@@ -633,13 +629,13 @@ outrel:
                                 return -EFAULT;
                         return 0;
                 }
+
 #ifdef CONFIG_COMPAT
         case NCP_IOC_SETOBJECTNAME_32:
 #endif
         case NCP_IOC_SETOBJECTNAME:
-                if (current->uid != server->m.mounted_uid) {
+                if (uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 {
                         struct ncp_objectname_ioctl user;
                         void* newname;
@@ -691,13 +687,13 @@ outrel:
                         kfree(oldname);
                         return 0;
                 }
+
 #ifdef CONFIG_COMPAT
         case NCP_IOC_GETPRIVATEDATA_32:
 #endif
         case NCP_IOC_GETPRIVATEDATA:
-                if (current->uid != server->m.mounted_uid) {
+                if (uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 {
                         struct ncp_privatedata_ioctl user;
                         size_t outl;
@@ -736,13 +732,13 @@ outrel:
 
                         return 0;
                 }
+
 #ifdef CONFIG_COMPAT
         case NCP_IOC_SETPRIVATEDATA_32:
 #endif
         case NCP_IOC_SETPRIVATEDATA:
-                if (current->uid != server->m.mounted_uid) {
+                if (uid != server->m.mounted_uid)
                         return -EACCES;
-                }
                 {
                         struct ncp_privatedata_ioctl user;
                         void* new;
@@ -794,9 +790,10 @@ outrel:
 #endif /* CONFIG_NCPFS_NLS */
 
         case NCP_IOC_SETDENTRYTTL:
-                if ((file_permission(filp, MAY_WRITE) != 0) &&
-                                 (current->uid != server->m.mounted_uid))
+                if (file_permission(filp, MAY_WRITE) != 0 &&
+                    uid != server->m.mounted_uid)
                         return -EACCES;
+
                 {
                         u_int32_t user;