diff options
Diffstat (limited to 'fs/sysfs/inode.c')
| -rw-r--r-- | fs/sysfs/inode.c | 331 |
1 files changed, 0 insertions, 331 deletions
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c deleted file mode 100644 index 1750f79..0000000 --- a/fs/sysfs/inode.c +++ /dev/null @@ -1,331 +0,0 @@ -/* - * fs/sysfs/inode.c - basic sysfs inode and dentry operations - * - * 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. - */ - -#undef DEBUG - -#include <linux/pagemap.h> -#include <linux/namei.h> -#include <linux/backing-dev.h> -#include <linux/capability.h> -#include <linux/errno.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/sysfs.h> -#include <linux/xattr.h> -#include <linux/security.h> -#include "sysfs.h" - -static const struct address_space_operations sysfs_aops = { - .readpage = simple_readpage, - .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_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); -} - -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 = GLOBAL_ROOT_UID; - iattrs->ia_gid = GLOBAL_ROOT_GID; - iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME; - - return attrs; -} - -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; - - 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; - } - /* 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; - - mutex_lock(&sysfs_mutex); - error = inode_change_ok(inode, iattr); - if (error) - goto out; - - error = sysfs_sd_setattr(sd, iattr); - if (error) - goto out; - - /* this ignores size changes */ - setattr_copy(inode, 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; - - if (!sd->s_iattr) { - sd->s_iattr = sysfs_init_inode_attrs(sd); - if (!sd->s_iattr) - return -ENOMEM; - } - - iattrs = sd->s_iattr; - 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, umode_t mode) -{ - inode->i_mode = mode; - 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_uid = iattr->ia_uid; - inode->i_gid = iattr->ia_gid; - inode->i_atime = iattr->ia_atime; - inode->i_mtime = iattr->ia_mtime; - inode->i_ctime = iattr->ia_ctime; -} - -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) - set_nlink(inode, sd->s_dir.subdirs + 2); -} - -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; - - 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_attr.bin_attr; - inode->i_size = bin_attr->size; - inode->i_fop = &sysfs_bin_operations; - break; - case SYSFS_KOBJ_LINK: - inode->i_op = &sysfs_symlink_inode_operations; - break; - default: - BUG(); - } - - unlock_new_inode(inode); -} - -/** - * 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 - * is allocated and basics are initialized. New inode is - * returned locked. - * - * LOCKING: - * Kernel thread context (may sleep). - * - * RETURNS: - * Pointer to allocated inode on success, NULL on failure. - */ -struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd) -{ - struct inode *inode; - - inode = iget_locked(sb, sd->s_ino); - if (inode && (inode->i_state & I_NEW)) - sysfs_init_inode(sd, inode); - - return inode; -} - -/* - * 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.evict_inode() implementation is needed to drop that - * reference upon inode destruction. - */ -void sysfs_evict_inode(struct inode *inode) -{ - struct sysfs_dirent *sd = inode->i_private; - - truncate_inode_pages(&inode->i_data, 0); - clear_inode(inode); - sysfs_put(sd); -} - -int sysfs_permission(struct inode *inode, int mask) -{ - struct sysfs_dirent *sd; - - if (mask & MAY_NOT_BLOCK) - return -ECHILD; - - sd = inode->i_private; - - mutex_lock(&sysfs_mutex); - sysfs_refresh_inode(sd, inode); - mutex_unlock(&sysfs_mutex); - - return generic_permission(inode, mask); -} |