kernfs: implement "trusted.*" xattr support
kernfs inherited "security.*" xattr support from sysfs. This patch
extends xattr support to "trusted.*" using simple_xattr_*(). As
trusted xattrs are restricted to CAP_SYS_ADMIN, simple_xattr_*() which
uses kernel memory for storage shouldn't be problematic.
Note that the existing "security.*" support doesn't implement
get/remove/list and the this patch only implements those ops for
"trusted.*". We probably want to extend those ops to include support
for "security.*".
This patch will allow using kernfs from cgroup which requires
"trusted.*" xattr support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David P. Quigley <dpquigl@tycho.nsa.gov>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index a1f8382..18ad431 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -35,6 +35,9 @@
.setattr = sysfs_setattr,
.getattr = sysfs_getattr,
.setxattr = sysfs_setxattr,
+ .removexattr = sysfs_removexattr,
+ .getxattr = sysfs_getxattr,
+ .listxattr = sysfs_listxattr,
};
void __init sysfs_inode_init(void)
@@ -61,6 +64,8 @@
iattrs->ia_gid = GLOBAL_ROOT_GID;
iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME;
+ simple_xattrs_init(&sd->s_iattr->xattrs);
+
return sd->s_iattr;
}
@@ -162,23 +167,25 @@
size_t size, int flags)
{
struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_inode_attrs *attrs;
void *secdata;
int error;
u32 secdata_len = 0;
- if (!sd)
- return -EINVAL;
+ attrs = sysfs_inode_attrs(sd);
+ if (!attrs)
+ return -ENOMEM;
if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) {
const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
error = security_inode_setsecurity(dentry->d_inode, suffix,
value, size, flags);
if (error)
- goto out;
+ return error;
error = security_inode_getsecctx(dentry->d_inode,
&secdata, &secdata_len);
if (error)
- goto out;
+ return error;
mutex_lock(&sysfs_mutex);
error = sysfs_sd_setsecdata(sd, &secdata, &secdata_len);
@@ -186,10 +193,50 @@
if (secdata)
security_release_secctx(secdata, secdata_len);
- } else
- return -EINVAL;
-out:
- return error;
+ return error;
+ } else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) {
+ return simple_xattr_set(&attrs->xattrs, name, value, size,
+ flags);
+ }
+
+ return -EINVAL;
+}
+
+int sysfs_removexattr(struct dentry *dentry, const char *name)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_inode_attrs *attrs;
+
+ attrs = sysfs_inode_attrs(sd);
+ if (!attrs)
+ return -ENOMEM;
+
+ return simple_xattr_remove(&attrs->xattrs, name);
+}
+
+ssize_t sysfs_getxattr(struct dentry *dentry, const char *name, void *buf,
+ size_t size)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_inode_attrs *attrs;
+
+ attrs = sysfs_inode_attrs(sd);
+ if (!attrs)
+ return -ENOMEM;
+
+ return simple_xattr_get(&attrs->xattrs, name, buf, size);
+}
+
+ssize_t sysfs_listxattr(struct dentry *dentry, char *buf, size_t size)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_inode_attrs *attrs;
+
+ attrs = sysfs_inode_attrs(sd);
+ if (!attrs)
+ return -ENOMEM;
+
+ return simple_xattr_list(&attrs->xattrs, buf, size);
}
static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
