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>
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index f9765e8..b22abba 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -111,7 +111,7 @@
This can be used to share devices/named pipes/sockets between
hosts. This functionality will be expanded in later versions.
- access there are three access modes.
+ access there are four access modes.
user = if a user tries to access a file on v9fs
filesystem for the first time, v9fs sends an
attach command (Tattach) for that user.
@@ -120,6 +120,8 @@
the files on the mounted filesystem
any = v9fs does single attach and performs all
operations as one user
+ client = ACL based access check on the 9p client
+ side for access validation
cachetag cache tag to use the specified persistent cache.
cache tags for existing cache sessions can be listed at
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 8b3c54a..12d6023 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 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 @@
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 @@
}
+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 @@
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))
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 6406f89..b00223c 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -149,6 +149,7 @@
switch (access) {
case V9FS_ACCESS_SINGLE:
case V9FS_ACCESS_USER:
+ case V9FS_ACCESS_CLIENT:
uid = current_fsuid();
any = 0;
break;
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 38dc0e0..2f77cd3 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -193,7 +193,17 @@
v9ses->flags |= V9FS_ACCESS_USER;
else if (strcmp(s, "any") == 0)
v9ses->flags |= V9FS_ACCESS_ANY;
- else {
+ else if (strcmp(s, "client") == 0) {
+#ifdef CONFIG_9P_FS_POSIX_ACL
+ v9ses->flags |= V9FS_ACCESS_CLIENT;
+#else
+ P9_DPRINTK(P9_DEBUG_ERROR,
+ "access=client option not supported\n");
+ kfree(s);
+ ret = -EINVAL;
+ goto free_and_return;
+#endif
+ } else {
v9ses->flags |= V9FS_ACCESS_SINGLE;
v9ses->uid = simple_strtoul(s, &e, 10);
if (*e != '\0')
@@ -278,6 +288,16 @@
v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
+ if (!v9fs_proto_dotl(v9ses) &&
+ ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
+ /*
+ * We support ACCESS_CLIENT only for dotl.
+ * Fall back to ACCESS_USER
+ */
+ v9ses->flags &= ~V9FS_ACCESS_MASK;
+ v9ses->flags |= V9FS_ACCESS_USER;
+ }
+ /*FIXME !! */
/* for legacy mode, fall back to V9FS_ACCESS_ANY */
if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 4c963c9..8bb7792 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -33,13 +33,17 @@
*
* Session flags reflect options selected by users at mount time
*/
+#define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
+ V9FS_ACCESS_USER | \
+ V9FS_ACCESS_CLIENT)
+#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
+
enum p9_session_flags {
V9FS_PROTO_2000U = 0x01,
V9FS_PROTO_2000L = 0x02,
V9FS_ACCESS_SINGLE = 0x04,
V9FS_ACCESS_USER = 0x08,
- V9FS_ACCESS_ANY = 0x0C,
- V9FS_ACCESS_MASK = 0x0C,
+ V9FS_ACCESS_CLIENT = 0x10
};
/* possible values of ->cache */
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 14da577..174643f 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -90,7 +90,8 @@
MS_NOATIME;
#ifdef CONFIG_9P_FS_POSIX_ACL
- sb->s_flags |= MS_POSIXACL;
+ if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)
+ sb->s_flags |= MS_POSIXACL;
#endif
save_mount_options(sb, data);
@@ -181,7 +182,6 @@
retval = v9fs_get_acl(inode, fid);
if (retval)
goto release_sb;
-
v9fs_fid_add(root, fid);
P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");