diff options
Diffstat (limited to 'fs/configfs/dir.c')
-rw-r--r-- | fs/configfs/dir.c | 222 |
1 files changed, 165 insertions, 57 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index a7a1b218f308..f419519ec41f 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -255,6 +255,12 @@ static void configfs_init_file(struct inode * inode) inode->i_fop = &configfs_file_operations; } +static void configfs_init_bin_file(struct inode *inode) +{ + inode->i_size = 0; + inode->i_fop = &configfs_bin_file_operations; +} + static void init_symlink(struct inode * inode) { inode->i_op = &configfs_symlink_inode_operations; @@ -423,7 +429,9 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den spin_unlock(&configfs_dirent_lock); error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, - configfs_init_file); + (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ? + configfs_init_bin_file : + configfs_init_file); if (error) { configfs_put(sd); return error; @@ -583,6 +591,7 @@ static int populate_attrs(struct config_item *item) { struct config_item_type *t = item->ci_type; struct configfs_attribute *attr; + struct configfs_bin_attribute *bin_attr; int error = 0; int i; @@ -594,6 +603,13 @@ static int populate_attrs(struct config_item *item) break; } } + if (t->ct_bin_attrs) { + for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) { + error = configfs_create_bin_file(item, bin_attr); + if (error) + break; + } + } if (error) detach_attrs(item); @@ -624,13 +640,13 @@ static void detach_groups(struct config_group *group) child = sd->s_dentry; - mutex_lock(&d_inode(child)->i_mutex); + inode_lock(d_inode(child)); configfs_detach_group(sd->s_element); d_inode(child)->i_flags |= S_DEAD; dont_mount(child); - mutex_unlock(&d_inode(child)->i_mutex); + inode_unlock(d_inode(child)); d_delete(child); dput(child); @@ -818,11 +834,11 @@ static int configfs_attach_item(struct config_item *parent_item, * the VFS may already have hit and used them. Thus, * we must lock them as rmdir() would. */ - mutex_lock(&d_inode(dentry)->i_mutex); + inode_lock(d_inode(dentry)); configfs_remove_dir(item); d_inode(dentry)->i_flags |= S_DEAD; dont_mount(dentry); - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); d_delete(dentry); } } @@ -858,7 +874,7 @@ static int configfs_attach_group(struct config_item *parent_item, * We must also lock the inode to remove it safely in case of * error, as rmdir() would. */ - mutex_lock_nested(&d_inode(dentry)->i_mutex, I_MUTEX_CHILD); + inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD); configfs_adjust_dir_dirent_depth_before_populate(sd); ret = populate_groups(to_config_group(item)); if (ret) { @@ -867,7 +883,7 @@ static int configfs_attach_group(struct config_item *parent_item, dont_mount(dentry); } configfs_adjust_dir_dirent_depth_after_populate(sd); - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); if (ret) d_delete(dentry); } @@ -1054,11 +1070,55 @@ out: return ret; } +static int configfs_do_depend_item(struct dentry *subsys_dentry, + struct config_item *target) +{ + struct configfs_dirent *p; + int ret; + + spin_lock(&configfs_dirent_lock); + /* Scan the tree, return 0 if found */ + ret = configfs_depend_prep(subsys_dentry, target); + if (ret) + goto out_unlock_dirent_lock; + + /* + * We are sure that the item is not about to be removed by rmdir(), and + * not in the middle of attachment by mkdir(). + */ + p = target->ci_dentry->d_fsdata; + p->s_dependent_count += 1; + +out_unlock_dirent_lock: + spin_unlock(&configfs_dirent_lock); + + return ret; +} + +static inline struct configfs_dirent * +configfs_find_subsys_dentry(struct configfs_dirent *root_sd, + struct config_item *subsys_item) +{ + struct configfs_dirent *p; + struct configfs_dirent *ret = NULL; + + list_for_each_entry(p, &root_sd->s_children, s_sibling) { + if (p->s_type & CONFIGFS_DIR && + p->s_element == subsys_item) { + ret = p; + break; + } + } + + return ret; +} + + int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target) { int ret; - struct configfs_dirent *p, *root_sd, *subsys_sd = NULL; + struct configfs_dirent *subsys_sd; struct config_item *s_item = &subsys->su_group.cg_item; struct dentry *root; @@ -1075,43 +1135,19 @@ int configfs_depend_item(struct configfs_subsystem *subsys, * subsystem is really registered, and so we need to lock out * configfs_[un]register_subsystem(). */ - mutex_lock(&d_inode(root)->i_mutex); - - root_sd = root->d_fsdata; - - list_for_each_entry(p, &root_sd->s_children, s_sibling) { - if (p->s_type & CONFIGFS_DIR) { - if (p->s_element == s_item) { - subsys_sd = p; - break; - } - } - } + inode_lock(d_inode(root)); + subsys_sd = configfs_find_subsys_dentry(root->d_fsdata, s_item); if (!subsys_sd) { ret = -ENOENT; goto out_unlock_fs; } /* Ok, now we can trust subsys/s_item */ + ret = configfs_do_depend_item(subsys_sd->s_dentry, target); - spin_lock(&configfs_dirent_lock); - /* Scan the tree, return 0 if found */ - ret = configfs_depend_prep(subsys_sd->s_dentry, target); - if (ret) - goto out_unlock_dirent_lock; - - /* - * We are sure that the item is not about to be removed by rmdir(), and - * not in the middle of attachment by mkdir(). - */ - p = target->ci_dentry->d_fsdata; - p->s_dependent_count += 1; - -out_unlock_dirent_lock: - spin_unlock(&configfs_dirent_lock); out_unlock_fs: - mutex_unlock(&d_inode(root)->i_mutex); + inode_unlock(d_inode(root)); /* * If we succeeded, the fs is pinned via other methods. If not, @@ -1128,8 +1164,7 @@ EXPORT_SYMBOL(configfs_depend_item); * configfs_depend_item() because we know that that the client driver is * pinned, thus the subsystem is pinned, and therefore configfs is pinned. */ -void configfs_undepend_item(struct configfs_subsystem *subsys, - struct config_item *target) +void configfs_undepend_item(struct config_item *target) { struct configfs_dirent *sd; @@ -1152,6 +1187,79 @@ void configfs_undepend_item(struct configfs_subsystem *subsys, } EXPORT_SYMBOL(configfs_undepend_item); +/* + * caller_subsys is a caller's subsystem not target's. This is used to + * determine if we should lock root and check subsys or not. When we are + * in the same subsystem as our target there is no need to do locking as + * we know that subsys is valid and is not unregistered during this function + * as we are called from callback of one of his children and VFS holds a lock + * on some inode. Otherwise we have to lock our root to ensure that target's + * subsystem it is not unregistered during this function. + */ +int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys, + struct config_item *target) +{ + struct configfs_subsystem *target_subsys; + struct config_group *root, *parent; + struct configfs_dirent *subsys_sd; + int ret = -ENOENT; + + /* Disallow this function for configfs root */ + if (configfs_is_root(target)) + return -EINVAL; + + parent = target->ci_group; + /* + * This may happen when someone is trying to depend root + * directory of some subsystem + */ + if (configfs_is_root(&parent->cg_item)) { + target_subsys = to_configfs_subsystem(to_config_group(target)); + root = parent; + } else { + target_subsys = parent->cg_subsys; + /* Find a cofnigfs root as we may need it for locking */ + for (root = parent; !configfs_is_root(&root->cg_item); + root = root->cg_item.ci_group) + ; + } + + if (target_subsys != caller_subsys) { + /* + * We are in other configfs subsystem, so we have to do + * additional locking to prevent other subsystem from being + * unregistered + */ + inode_lock(d_inode(root->cg_item.ci_dentry)); + + /* + * As we are trying to depend item from other subsystem + * we have to check if this subsystem is still registered + */ + subsys_sd = configfs_find_subsys_dentry( + root->cg_item.ci_dentry->d_fsdata, + &target_subsys->su_group.cg_item); + if (!subsys_sd) + goto out_root_unlock; + } else { + subsys_sd = target_subsys->su_group.cg_item.ci_dentry->d_fsdata; + } + + /* Now we can execute core of depend item */ + ret = configfs_do_depend_item(subsys_sd->s_dentry, target); + + if (target_subsys != caller_subsys) +out_root_unlock: + /* + * We were called from subsystem other than our target so we + * took some locks so now it's time to release them + */ + inode_unlock(d_inode(root->cg_item.ci_dentry)); + + return ret; +} +EXPORT_SYMBOL(configfs_depend_item_unlocked); + static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { int ret = 0; @@ -1453,7 +1561,7 @@ int configfs_rename_dir(struct config_item * item, const char *new_name) down_write(&configfs_rename_sem); parent = item->parent->dentry; - mutex_lock(&d_inode(parent)->i_mutex); + inode_lock(d_inode(parent)); new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); if (!IS_ERR(new_dentry)) { @@ -1469,7 +1577,7 @@ int configfs_rename_dir(struct config_item * item, const char *new_name) error = -EEXIST; dput(new_dentry); } - mutex_unlock(&d_inode(parent)->i_mutex); + inode_unlock(d_inode(parent)); up_write(&configfs_rename_sem); return error; @@ -1482,7 +1590,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file) struct configfs_dirent * parent_sd = dentry->d_fsdata; int err; - mutex_lock(&d_inode(dentry)->i_mutex); + inode_lock(d_inode(dentry)); /* * Fake invisibility if dir belongs to a group/default groups hierarchy * being attached @@ -1495,7 +1603,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file) else err = 0; } - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); return err; } @@ -1505,11 +1613,11 @@ static int configfs_dir_close(struct inode *inode, struct file *file) struct dentry * dentry = file->f_path.dentry; struct configfs_dirent * cursor = file->private_data; - mutex_lock(&d_inode(dentry)->i_mutex); + inode_lock(d_inode(dentry)); spin_lock(&configfs_dirent_lock); list_del_init(&cursor->s_sibling); spin_unlock(&configfs_dirent_lock); - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); release_configfs_dirent(cursor); @@ -1590,7 +1698,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) { struct dentry * dentry = file->f_path.dentry; - mutex_lock(&d_inode(dentry)->i_mutex); + inode_lock(d_inode(dentry)); switch (whence) { case 1: offset += file->f_pos; @@ -1598,7 +1706,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) if (offset >= 0) break; default: - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); return -EINVAL; } if (offset != file->f_pos) { @@ -1624,7 +1732,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) spin_unlock(&configfs_dirent_lock); } } - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); return offset; } @@ -1659,14 +1767,14 @@ int configfs_register_group(struct config_group *parent_group, parent = parent_group->cg_item.ci_dentry; - mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT); + inode_lock_nested(d_inode(parent), I_MUTEX_PARENT); ret = create_default_group(parent_group, group); if (!ret) { spin_lock(&configfs_dirent_lock); configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata); spin_unlock(&configfs_dirent_lock); } - mutex_unlock(&d_inode(parent)->i_mutex); + inode_unlock(d_inode(parent)); return ret; } EXPORT_SYMBOL(configfs_register_group); @@ -1683,7 +1791,7 @@ void configfs_unregister_group(struct config_group *group) struct dentry *dentry = group->cg_item.ci_dentry; struct dentry *parent = group->cg_item.ci_parent->ci_dentry; - mutex_lock_nested(&d_inode(parent)->i_mutex, I_MUTEX_PARENT); + inode_lock_nested(d_inode(parent), I_MUTEX_PARENT); spin_lock(&configfs_dirent_lock); configfs_detach_prep(dentry, NULL); spin_unlock(&configfs_dirent_lock); @@ -1692,7 +1800,7 @@ void configfs_unregister_group(struct config_group *group) d_inode(dentry)->i_flags |= S_DEAD; dont_mount(dentry); d_delete(dentry); - mutex_unlock(&d_inode(parent)->i_mutex); + inode_unlock(d_inode(parent)); dput(dentry); @@ -1764,7 +1872,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) sd = root->d_fsdata; link_group(to_config_group(sd->s_element), group); - mutex_lock_nested(&d_inode(root)->i_mutex, I_MUTEX_PARENT); + inode_lock_nested(d_inode(root), I_MUTEX_PARENT); err = -ENOMEM; dentry = d_alloc_name(root, group->cg_item.ci_name); @@ -1784,7 +1892,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) } } - mutex_unlock(&d_inode(root)->i_mutex); + inode_unlock(d_inode(root)); if (err) { unlink_group(group); @@ -1805,9 +1913,9 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) return; } - mutex_lock_nested(&d_inode(root)->i_mutex, + inode_lock_nested(d_inode(root), I_MUTEX_PARENT); - mutex_lock_nested(&d_inode(dentry)->i_mutex, I_MUTEX_CHILD); + inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD); mutex_lock(&configfs_symlink_mutex); spin_lock(&configfs_dirent_lock); if (configfs_detach_prep(dentry, NULL)) { @@ -1818,11 +1926,11 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) configfs_detach_group(&group->cg_item); d_inode(dentry)->i_flags |= S_DEAD; dont_mount(dentry); - mutex_unlock(&d_inode(dentry)->i_mutex); + inode_unlock(d_inode(dentry)); d_delete(dentry); - mutex_unlock(&d_inode(root)->i_mutex); + inode_unlock(d_inode(root)); dput(dentry); |