/*
- * inode.c - basic inode and dentry operations.
+ * fs/sysfs/inode.c - basic sysfs inode and dentry operations
*
- * sysfs is Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
*
* Please see Documentation/filesystems/sysfs.txt for more information.
*/
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/sched.h>
-#include <asm/semaphore.h>
+#include <linux/xattr.h>
+#include <linux/security.h>
#include "sysfs.h"
extern struct super_block * sysfs_sb;
static const struct address_space_operations sysfs_aops = {
.readpage = simple_readpage,
- .prepare_write = simple_prepare_write,
- .commit_write = simple_commit_write
+ .write_begin = simple_write_begin,
+ .write_end = simple_write_end,
};
static struct backing_dev_info sysfs_backing_dev_info = {
+ .name = "sysfs",
.ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+ .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,
};
-void sysfs_delete_inode(struct inode *inode)
+int __init sysfs_inode_init(void)
{
- /* Free the shadowed directory inode operations */
- if (sysfs_is_shadowed_inode(inode)) {
- kfree(inode->i_op);
- inode->i_op = NULL;
- }
- return generic_delete_inode(inode);
+ return bdi_init(&sysfs_backing_dev_info);
+}
+
+static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd)
+{
+ struct sysfs_inode_attrs *attrs;
+ struct iattr *iattrs;
+
+ attrs = kzalloc(sizeof(struct sysfs_inode_attrs), GFP_KERNEL);
+ if (!attrs)
+ return NULL;
+ iattrs = &attrs->ia_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;
+
+ return attrs;
}
-int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
+int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr * iattr)
{
- struct inode * inode = dentry->d_inode;
- struct sysfs_dirent * sd = dentry->d_fsdata;
- struct iattr * sd_iattr;
+ struct sysfs_inode_attrs *sd_attrs;
+ struct iattr *iattrs;
unsigned int ia_valid = iattr->ia_valid;
+
+ sd_attrs = sd->s_iattr;
+
+ if (!sd_attrs) {
+ /* setting attributes for the first time, allocate now */
+ sd_attrs = sysfs_init_inode_attrs(sd);
+ if (!sd_attrs)
+ return -ENOMEM;
+ sd->s_iattr = sd_attrs;
+ } else {
+ /* attributes were changed at least once in past */
+ iattrs = &sd_attrs->ia_iattr;
+
+ if (ia_valid & ATTR_UID)
+ iattrs->ia_uid = iattr->ia_uid;
+ if (ia_valid & ATTR_GID)
+ iattrs->ia_gid = iattr->ia_gid;
+ if (ia_valid & ATTR_ATIME)
+ iattrs->ia_atime = iattr->ia_atime;
+ if (ia_valid & ATTR_MTIME)
+ iattrs->ia_mtime = iattr->ia_mtime;
+ if (ia_valid & ATTR_CTIME)
+ iattrs->ia_ctime = iattr->ia_ctime;
+ if (ia_valid & ATTR_MODE) {
+ umode_t mode = iattr->ia_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;
- sd_iattr = sd->s_iattr;
-
error = inode_change_ok(inode, iattr);
if (error)
return error;
+ iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
+
error = inode_setattr(inode, iattr);
if (error)
return error;
- if (!sd_iattr) {
- /* setting attributes for the first time, allocate now */
- sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
- if (!sd_iattr)
- 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;
- }
+ mutex_lock(&sysfs_mutex);
+ error = sysfs_sd_setattr(sd, iattr);
+ mutex_unlock(&sysfs_mutex);
- /* attributes were changed atleast once in past */
-
- if (ia_valid & ATTR_UID)
- sd_iattr->ia_uid = iattr->ia_uid;
- if (ia_valid & ATTR_GID)
- sd_iattr->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);
- if (ia_valid & ATTR_MTIME)
- sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
- inode->i_sb->s_time_gran);
- if (ia_valid & ATTR_CTIME)
- sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
- inode->i_sb->s_time_gran);
- 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;
- }
+ 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_default_inode_attr(struct inode * inode, mode_t mode)
{
inode->i_mode = mode;
- inode->i_uid = 0;
- inode->i_gid = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
}
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;
}
+static int sysfs_count_nlink(struct sysfs_dirent *sd)
+{
+ struct sysfs_dirent *child;
+ int nr = 0;
-/*
- * 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;
+ for (child = sd->s_dir.children; child; child = child->s_sibling)
+ if (sysfs_type(child) == SYSFS_DIR)
+ nr++;
-void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
+ return nr + 2;
+}
+
+static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode)
{
- inode->i_blocks = 0;
+ 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_private = sysfs_get(sd);
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;
+ break;
+ case SYSFS_KOBJ_ATTR:
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &sysfs_file_operations;
+ break;
+ case SYSFS_KOBJ_BIN_ATTR:
+ bin_attr = sd->s_bin_attr.bin_attr;
+ inode->i_size = bin_attr->size;
+ inode->i_fop = &bin_fops;
+ break;
+ case SYSFS_KOBJ_LINK:
+ inode->i_op = &sysfs_symlink_inode_operations;
+ break;
+ default:
+ BUG();
+ }
+
+ unlock_new_inode(inode);
}
/**
return inode;
}
-/**
- * sysfs_instantiate - instantiate dentry
- * @dentry: dentry to be instantiated
- * @inode: inode associated with @sd
- *
- * Unlock @inode if locked and instantiate @dentry with @inode.
- *
- * LOCKING:
- * None.
+/*
+ * The sysfs_dirent serves as both an inode and a directory entry for sysfs.
+ * To prevent the sysfs inode numbers from being freed prematurely we take a
+ * reference to sysfs_dirent from the sysfs inode. A
+ * super_operations.delete_inode() implementation is needed to drop that
+ * reference upon inode destruction.
*/
-void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
+void sysfs_delete_inode(struct inode *inode)
{
- BUG_ON(!dentry || dentry->d_inode);
-
- if (inode->i_state & I_NEW) {
- unlock_new_inode(inode);
-
- if (dentry->d_parent && dentry->d_parent->d_inode) {
- struct inode *p_inode = dentry->d_parent->d_inode;
- p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
- }
- }
+ struct sysfs_dirent *sd = inode->i_private;
- d_instantiate(dentry, inode);
+ truncate_inode_pages(&inode->i_data, 0);
+ clear_inode(inode);
+ sysfs_put(sd);
}
-/**
- * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
- * @sd: target sysfs_dirent
- *
- * Drop dentry for @sd. @sd must have been unlinked from its
- * parent on entry to this function such that it can't be looked
- * up anymore.
- *
- * @sd->s_dentry which is protected with sysfs_lock points to the
- * currently associated dentry but we're not holding a reference
- * to it and racing with dput(). Grab dcache_lock and verify
- * dentry before dropping it. If @sd->s_dentry is NULL or dput()
- * beats us, no need to bother.
- */
-void sysfs_drop_dentry(struct sysfs_dirent *sd)
+int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
{
- struct dentry *dentry = NULL;
- struct timespec curtime;
- struct inode *inode;
-
- /* We're not holding a reference to ->s_dentry dentry but the
- * field will stay valid as long as sysfs_lock is held.
- */
- spin_lock(&sysfs_lock);
- spin_lock(&dcache_lock);
-
- /* drop dentry if it's there and dput() didn't kill it yet */
- if (sd->s_dentry && sd->s_dentry->d_inode) {
- dentry = dget_locked(sd->s_dentry);
- spin_lock(&dentry->d_lock);
- __d_drop(dentry);
- spin_unlock(&dentry->d_lock);
- }
+ struct sysfs_addrm_cxt acxt;
+ struct sysfs_dirent *sd;
- spin_unlock(&dcache_lock);
- spin_unlock(&sysfs_lock);
-
- dput(dentry);
- /* XXX: unpin if directory, this will go away soon */
- if (sd->s_type & SYSFS_DIR)
- dput(dentry);
-
- /* adjust nlink and update timestamp */
- curtime = CURRENT_TIME;
-
- inode = ilookup(sysfs_sb, sd->s_ino);
- if (inode) {
- mutex_lock(&inode->i_mutex);
-
- inode->i_ctime = curtime;
- drop_nlink(inode);
- if (sd->s_type & SYSFS_DIR)
- drop_nlink(inode);
+ if (!dir_sd)
+ return -ENOENT;
- mutex_unlock(&inode->i_mutex);
- iput(inode);
- }
+ sysfs_addrm_start(&acxt, dir_sd);
- /* adjust nlink and udpate timestamp of the parent */
- inode = ilookup(sysfs_sb, sd->s_parent->s_ino);
- if (inode) {
- mutex_lock(&inode->i_mutex);
+ sd = sysfs_find_dirent(dir_sd, name);
+ if (sd)
+ sysfs_remove_one(&acxt, sd);
- inode->i_ctime = inode->i_mtime = curtime;
- if (sd->s_type & SYSFS_DIR)
- drop_nlink(inode);
+ sysfs_addrm_finish(&acxt);
- mutex_unlock(&inode->i_mutex);
- iput(inode);
- }
+ if (sd)
+ return 0;
+ else
+ return -ENOENT;
}
-int sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_permission(struct inode *inode, int mask)
{
- struct sysfs_dirent **pos, *sd;
- struct sysfs_dirent *parent_sd;
- int found = 0;
+ struct sysfs_dirent *sd = inode->i_private;
- if (!dir)
- return -ENOENT;
+ mutex_lock(&sysfs_mutex);
+ sysfs_refresh_inode(sd, inode);
+ mutex_unlock(&sysfs_mutex);
- if (dir->d_inode == NULL)
- /* no inode means this hasn't been made visible yet */
- return -ENOENT;
-
- parent_sd = dir->d_fsdata;
- mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
- for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
- sd = *pos;
-
- if (!sd->s_type)
- continue;
- if (!strcmp(sd->s_name, name)) {
- *pos = sd->s_sibling;
- sd->s_sibling = NULL;
- found = 1;
- break;
- }
- }
- mutex_unlock(&dir->d_inode->i_mutex);
-
- if (!found)
- return -ENOENT;
-
- sysfs_drop_dentry(sd);
- sysfs_deactivate(sd);
- sysfs_put(sd);
-
- return 0;
+ return generic_permission(inode, mask, NULL);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff