#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/security.h>
#include "sysfs.h"
extern struct super_block * sysfs_sb;
};
static struct backing_dev_info sysfs_backing_dev_info = {
+ .name = "sysfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static const struct inode_operations sysfs_inode_operations ={
+ .permission = sysfs_permission,
.setattr = sysfs_setattr,
+ .getattr = sysfs_getattr,
+ .setxattr = sysfs_setxattr,
};
int __init sysfs_inode_init(void)
return bdi_init(&sysfs_backing_dev_info);
}
-int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
+static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd)
{
- struct inode * inode = dentry->d_inode;
- struct sysfs_dirent * sd = dentry->d_fsdata;
- struct iattr * sd_iattr;
- unsigned int ia_valid = iattr->ia_valid;
- int error;
+ struct sysfs_inode_attrs *attrs;
+ struct iattr *iattrs;
- if (!sd)
- return -EINVAL;
+ attrs = kzalloc(sizeof(struct sysfs_inode_attrs), GFP_KERNEL);
+ if (!attrs)
+ return NULL;
+ iattrs = &attrs->ia_iattr;
- sd_iattr = sd->s_iattr;
+ /* assign default attributes */
+ iattrs->ia_mode = sd->s_mode;
+ iattrs->ia_uid = 0;
+ iattrs->ia_gid = 0;
+ iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME;
- error = inode_change_ok(inode, iattr);
- if (error)
- return error;
+ return attrs;
+}
- iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
+int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr * iattr)
+{
+ struct sysfs_inode_attrs *sd_attrs;
+ struct iattr *iattrs;
+ unsigned int ia_valid = iattr->ia_valid;
- error = inode_setattr(inode, iattr);
- if (error)
- return error;
+ sd_attrs = sd->s_iattr;
- if (!sd_iattr) {
+ if (!sd_attrs) {
/* setting attributes for the first time, allocate now */
- sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
- if (!sd_iattr)
+ sd_attrs = sysfs_init_inode_attrs(sd);
+ if (!sd_attrs)
return -ENOMEM;
- /* assign default attributes */
- sd_iattr->ia_mode = sd->s_mode;
- sd_iattr->ia_uid = 0;
- sd_iattr->ia_gid = 0;
- sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
- sd->s_iattr = sd_iattr;
+ sd->s_iattr = sd_attrs;
}
-
- /* attributes were changed atleast once in past */
+ /* attributes were changed at least once in past */
+ iattrs = &sd_attrs->ia_iattr;
if (ia_valid & ATTR_UID)
- sd_iattr->ia_uid = iattr->ia_uid;
+ iattrs->ia_uid = iattr->ia_uid;
if (ia_valid & ATTR_GID)
- sd_iattr->ia_gid = iattr->ia_gid;
+ iattrs->ia_gid = iattr->ia_gid;
if (ia_valid & ATTR_ATIME)
- sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
- inode->i_sb->s_time_gran);
+ iattrs->ia_atime = iattr->ia_atime;
if (ia_valid & ATTR_MTIME)
- sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
- inode->i_sb->s_time_gran);
+ iattrs->ia_mtime = iattr->ia_mtime;
if (ia_valid & ATTR_CTIME)
- sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
- inode->i_sb->s_time_gran);
+ iattrs->ia_ctime = iattr->ia_ctime;
if (ia_valid & ATTR_MODE) {
umode_t mode = iattr->ia_mode;
-
- if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
- mode &= ~S_ISGID;
- sd_iattr->ia_mode = sd->s_mode = mode;
+ iattrs->ia_mode = sd->s_mode = mode;
}
+ return 0;
+}
+
+int sysfs_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = dentry->d_inode;
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ int error;
+
+ if (!sd)
+ return -EINVAL;
+
+ mutex_lock(&sysfs_mutex);
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ goto out;
+
+ iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
+
+ error = inode_setattr(inode, iattr);
+ if (error)
+ goto out;
+ error = sysfs_sd_setattr(sd, iattr);
+out:
+ mutex_unlock(&sysfs_mutex);
+ return error;
+}
+
+static int sysfs_sd_setsecdata(struct sysfs_dirent *sd, void **secdata, u32 *secdata_len)
+{
+ struct sysfs_inode_attrs *iattrs;
+ void *old_secdata;
+ size_t old_secdata_len;
+
+ iattrs = sd->s_iattr;
+ if (!iattrs)
+ iattrs = sysfs_init_inode_attrs(sd);
+ if (!iattrs)
+ return -ENOMEM;
+
+ old_secdata = iattrs->ia_secdata;
+ old_secdata_len = iattrs->ia_secdata_len;
+
+ iattrs->ia_secdata = *secdata;
+ iattrs->ia_secdata_len = *secdata_len;
+
+ *secdata = old_secdata;
+ *secdata_len = old_secdata_len;
+ return 0;
+}
+
+int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ void *secdata;
+ int error;
+ u32 secdata_len = 0;
+
+ if (!sd)
+ return -EINVAL;
+
+ 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;
+ error = security_inode_getsecctx(dentry->d_inode,
+ &secdata, &secdata_len);
+ if (error)
+ goto out;
+
+ mutex_lock(&sysfs_mutex);
+ error = sysfs_sd_setsecdata(sd, &secdata, &secdata_len);
+ mutex_unlock(&sysfs_mutex);
+
+ if (secdata)
+ security_release_secctx(secdata, secdata_len);
+ } else
+ return -EINVAL;
+out:
return error;
}
static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
{
- inode->i_mode = iattr->ia_mode;
inode->i_uid = iattr->ia_uid;
inode->i_gid = iattr->ia_gid;
inode->i_atime = iattr->ia_atime;
inode->i_ctime = iattr->ia_ctime;
}
-
-/*
- * sysfs has a different i_mutex lock order behavior for i_mutex than other
- * filesystems; sysfs i_mutex is called in many places with subsystem locks
- * held. At the same time, many of the VFS locking rules do not apply to
- * sysfs at all (cross directory rename for example). To untangle this mess
- * (which gives false positives in lockdep), we're giving sysfs inodes their
- * own class for i_mutex.
- */
-static struct lock_class_key sysfs_inode_imutex_key;
-
static int sysfs_count_nlink(struct sysfs_dirent *sd)
{
struct sysfs_dirent *child;
return nr + 2;
}
+static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode)
+{
+ struct sysfs_inode_attrs *iattrs = sd->s_iattr;
+
+ inode->i_mode = sd->s_mode;
+ if (iattrs) {
+ /* sysfs_dirent has non-default attributes
+ * get them from persistent copy in sysfs_dirent
+ */
+ set_inode_attr(inode, &iattrs->ia_iattr);
+ security_inode_notifysecctx(inode,
+ iattrs->ia_secdata,
+ iattrs->ia_secdata_len);
+ }
+
+ if (sysfs_type(sd) == SYSFS_DIR)
+ inode->i_nlink = sysfs_count_nlink(sd);
+}
+
+int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct inode *inode = dentry->d_inode;
+
+ mutex_lock(&sysfs_mutex);
+ sysfs_refresh_inode(sd, inode);
+ mutex_unlock(&sysfs_mutex);
+
+ generic_fillattr(inode, stat);
+ return 0;
+}
+
static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
{
struct bin_attribute *bin_attr;
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
- inode->i_ino = sd->s_ino;
- lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
-
- if (sd->s_iattr) {
- /* sysfs_dirent has non-default attributes
- * get them for the new inode from persistent copy
- * in sysfs_dirent
- */
- set_inode_attr(inode, sd->s_iattr);
- } else
- set_default_inode_attr(inode, sd->s_mode);
+ set_default_inode_attr(inode, sd->s_mode);
+ sysfs_refresh_inode(sd, inode);
/* initialize inode according to type */
switch (sysfs_type(sd)) {
case SYSFS_DIR:
inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
- inode->i_nlink = sysfs_count_nlink(sd);
break;
case SYSFS_KOBJ_ATTR:
inode->i_size = PAGE_SIZE;
/**
* sysfs_get_inode - get inode for sysfs_dirent
+ * @sb: super block
* @sd: sysfs_dirent to allocate inode for
*
* Get inode for @sd. If such inode doesn't exist, a new inode
* RETURNS:
* Pointer to allocated inode on success, NULL on failure.
*/
-struct inode * sysfs_get_inode(struct sysfs_dirent *sd)
+struct inode * sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd)
{
struct inode *inode;
- inode = iget_locked(sysfs_sb, sd->s_ino);
+ inode = iget_locked(sb, sd->s_ino);
if (inode && (inode->i_state & I_NEW))
sysfs_init_inode(sd, inode);
else
return -ENOENT;
}
+
+int sysfs_permission(struct inode *inode, int mask)
+{
+ struct sysfs_dirent *sd = inode->i_private;
+
+ mutex_lock(&sysfs_mutex);
+ sysfs_refresh_inode(sd, inode);
+ mutex_unlock(&sysfs_mutex);
+
+ return generic_permission(inode, mask, NULL);
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff