X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsysfs%2Finode.c;h=a4a0a9419711be52782e7afa4f9c81f9cb587658;hb=61d5eb2985b3b1d69fd53d7dc9789037c27f8d91;hp=e2f6ef138d20e4d957ad68870bdbe8a708846a55;hpb=380e6fbb729a55b73d5d8409551474884e0d93fc;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index e2f6ef1..a4a0a94 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -1,7 +1,11 @@ /* - * 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 + * + * This file is released under the GPLv2. * * Please see Documentation/filesystems/sysfs.txt for more information. */ @@ -14,107 +18,182 @@ #include #include #include -#include +#include +#include +#include #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); } -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; +} - error = inode_setattr(inode, iattr); - if (error) - return error; +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_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_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; @@ -122,38 +201,90 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) 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); } /** * 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 @@ -166,151 +297,62 @@ void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *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); 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); - } - - spin_unlock(&dcache_lock); - spin_unlock(&sysfs_lock); - - dput(dentry); - /* XXX: unpin if directory, this will go away soon */ - if (sysfs_type(sd) == 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); + struct sysfs_addrm_cxt acxt; + struct sysfs_dirent *sd; - inode->i_ctime = curtime; - drop_nlink(inode); - if (sysfs_type(sd) == 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 (sysfs_type(sd) == 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; - - if (!dir) - return -ENOENT; - - 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 (!sysfs_type(sd)) - continue; - if (!strcmp(sd->s_name, name)) { - sd->s_flags |= SYSFS_FLAG_REMOVED; - *pos = sd->s_sibling; - sd->s_sibling = NULL; - found = 1; - break; - } - } - mutex_unlock(&dir->d_inode->i_mutex); + struct sysfs_dirent *sd = inode->i_private; - if (!found) - return -ENOENT; + mutex_lock(&sysfs_mutex); + sysfs_refresh_inode(sd, inode); + mutex_unlock(&sysfs_mutex); - sysfs_drop_dentry(sd); - sysfs_deactivate(sd); - sysfs_put(sd); - - return 0; + return generic_permission(inode, mask, NULL); }