[PATCH -V2 6/6] fs/9p: Add access = client option to opt in acl evaluation.
From: Aneesh Kumar K.V
Date: Thu Aug 26 2010 - 07:21:29 EST
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/9p.txt | 4 +++-
fs/9p/acl.c | 37 ++++++++++++++++++++++++++++++++++++-
fs/9p/fid.c | 1 +
fs/9p/v9fs.c | 12 ++++++++++++
fs/9p/v9fs.h | 8 ++++++--
fs/9p/vfs_inode.c | 14 ++++++++++----
fs/9p/vfs_super.c | 16 +++++++++++-----
7 files changed, 79 insertions(+), 13 deletions(-)
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index c0236e7..1a48155 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -111,7 +111,7 @@ OPTIONS
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 @@ OPTIONS
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 e7982a1..96fa9fc 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -21,6 +21,7 @@
#include <linux/posix_acl_xattr.h>
#include "xattr.h"
#include "v9fs_vfs.h"
+#include "v9fs.h"
static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
@@ -85,7 +86,18 @@ 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);
@@ -208,7 +220,13 @@ static size_t v9fs_xattr_list_acl_access(struct dentry *dentry, char *list,
size_t list_len, const char *name,
size_t name_len, int type)
{
+ struct v9fs_session_info *v9ses;
const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
+
+ v9ses = v9fs_inode2v9ses(dentry->d_inode);
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return 0;
+
if (list && size <= list_len)
memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
return size;
@@ -218,7 +236,13 @@ static size_t v9fs_xattr_list_acl_default(struct dentry *dentry, char *list,
size_t list_len, const char *name,
size_t name_len, int type)
{
+ struct v9fs_session_info *v9ses;
const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
+
+ v9ses = v9fs_inode2v9ses(dentry->d_inode);
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return 0;
+
if (list && size <= list_len)
memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
return size;
@@ -227,12 +251,17 @@ static size_t v9fs_xattr_list_acl_default(struct dentry *dentry, char *list,
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);
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return -EOPNOTSUPP;
+
acl = v9fs_get_cached_acl(dentry->d_inode, type);
if (IS_ERR(acl))
return PTR_ERR(acl);
@@ -250,10 +279,16 @@ static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
{
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);
+ if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
+ return -EOPNOTSUPP;
+
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 3585636..4876a0e 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -149,6 +149,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
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..735ff25 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -193,6 +193,8 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
v9ses->flags |= V9FS_ACCESS_USER;
else if (strcmp(s, "any") == 0)
v9ses->flags |= V9FS_ACCESS_ANY;
+ else if (strcmp(s, "client") == 0)
+ v9ses->flags |= V9FS_ACCESS_CLIENT;
else {
v9ses->flags |= V9FS_ACCESS_SINGLE;
v9ses->uid = simple_strtoul(s, &e, 10);
@@ -278,6 +280,16 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
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_inode.c b/fs/9p/vfs_inode.c
index 3e365f6..9040db5 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -500,10 +500,16 @@ v9fs_inode_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
v9fs_vcookie_set_qid(ret, &st->qid);
v9fs_cache_inode_get_cookie(ret);
#endif
- err = v9fs_get_acl(ret, fid);
- if (err) {
- iput(ret);
- goto error;
+ if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT) {
+ /*
+ * On access = client mode get the acl
+ * values from the server
+ */
+ err = v9fs_get_acl(ret, fid);
+ if (err) {
+ iput(ret);
+ goto error;
+ }
}
kfree(st);
return ret;
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index a120a48..e15e9ac 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -90,7 +90,8 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
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);
@@ -178,10 +179,15 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
p9stat_free(st);
kfree(st);
}
- retval = v9fs_get_acl(inode, fid);
- if (retval)
- goto release_sb;
-
+ if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT) {
+ /*
+ * On access = client mode get the acl
+ * values from the server
+ */
+ 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");
--
1.7.0.4
--
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