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fs/configfs/dir.c
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/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * dir.c - Operations for configfs directories. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. * * Based on sysfs: * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel * * configfs Copyright (C) 2005 Oracle. All rights reserved. */ #undef DEBUG #include <linux/fs.h> #include <linux/mount.h> #include <linux/module.h> #include <linux/slab.h> |
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#include <linux/err.h> |
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#include <linux/configfs.h> #include "configfs_internal.h" DECLARE_RWSEM(configfs_rename_sem); |
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/* * Protects mutations of configfs_dirent linkage together with proper i_mutex |
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* Also protects mutations of symlinks linkage to target configfs_dirent |
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* Mutators of configfs_dirent linkage must *both* have the proper inode locked * and configfs_dirent_lock locked, in that order. |
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* This allows one to safely traverse configfs_dirent trees and symlinks without * having to lock inodes. |
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* * Protects setting of CONFIGFS_USET_DROPPING: checking the flag * unlocked is not reliable unless in detach_groups() called from * rmdir()/unregister() and from configfs_attach_group() |
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*/ DEFINE_SPINLOCK(configfs_dirent_lock); |
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static void configfs_d_iput(struct dentry * dentry, struct inode * inode) { struct configfs_dirent * sd = dentry->d_fsdata; if (sd) { BUG_ON(sd->s_dentry != dentry); sd->s_dentry = NULL; configfs_put(sd); } iput(inode); } /* * We _must_ delete our dentries on last dput, as the chain-to-parent * behavior is required to clear the parents of default_groups. */ static int configfs_d_delete(struct dentry *dentry) { return 1; } |
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static const struct dentry_operations configfs_dentry_ops = { |
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.d_iput = configfs_d_iput, /* simple_delete_dentry() isn't exported */ .d_delete = configfs_d_delete, }; |
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#ifdef CONFIG_LOCKDEP /* * Helpers to make lockdep happy with our recursive locking of default groups' * inodes (see configfs_attach_group() and configfs_detach_group()). * We put default groups i_mutexes in separate classes according to their depth * from the youngest non-default group ancestor. * * For a non-default group A having default groups A/B, A/C, and A/C/D, default * groups A/B and A/C will have their inode's mutex in class * default_group_class[0], and default group A/C/D will be in * default_group_class[1]. * * The lock classes are declared and assigned in inode.c, according to the * s_depth value. * The s_depth value is initialized to -1, adjusted to >= 0 when attaching * default groups, and reset to -1 when all default groups are attached. During * attachment, if configfs_create() sees s_depth > 0, the lock class of the new * inode's mutex is set to default_group_class[s_depth - 1]. */ static void configfs_init_dirent_depth(struct configfs_dirent *sd) { sd->s_depth = -1; } static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd, struct configfs_dirent *sd) { int parent_depth = parent_sd->s_depth; if (parent_depth >= 0) sd->s_depth = parent_depth + 1; } static void configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd) { /* * item's i_mutex class is already setup, so s_depth is now only * used to set new sub-directories s_depth, which is always done * with item's i_mutex locked. */ /* * sd->s_depth == -1 iff we are a non default group. * else (we are a default group) sd->s_depth > 0 (see * create_dir()). */ if (sd->s_depth == -1) /* * We are a non default group and we are going to create * default groups. */ sd->s_depth = 0; } static void configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd) { /* We will not create default groups anymore. */ sd->s_depth = -1; } #else /* CONFIG_LOCKDEP */ static void configfs_init_dirent_depth(struct configfs_dirent *sd) { } static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd, struct configfs_dirent *sd) { } static void configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd) { } static void configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd) { } #endif /* CONFIG_LOCKDEP */ |
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/* * Allocates a new configfs_dirent and links it to the parent configfs_dirent */ |
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static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd, void *element, int type) |
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{ struct configfs_dirent * sd; |
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sd = kmem_cache_zalloc(configfs_dir_cachep, GFP_KERNEL); |
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if (!sd) |
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return ERR_PTR(-ENOMEM); |
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|
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atomic_set(&sd->s_count, 1); INIT_LIST_HEAD(&sd->s_links); INIT_LIST_HEAD(&sd->s_children); |
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sd->s_element = element; |
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sd->s_type = type; |
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configfs_init_dirent_depth(sd); |
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spin_lock(&configfs_dirent_lock); |
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if (parent_sd->s_type & CONFIGFS_USET_DROPPING) { spin_unlock(&configfs_dirent_lock); kmem_cache_free(configfs_dir_cachep, sd); return ERR_PTR(-ENOENT); } |
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list_add(&sd->s_sibling, &parent_sd->s_children); spin_unlock(&configfs_dirent_lock); |
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return sd; } |
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/* * * Return -EEXIST if there is already a configfs element with the same * name for the same parent. * * called with parent inode's i_mutex held */ |
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static int configfs_dirent_exists(struct configfs_dirent *parent_sd, const unsigned char *new) |
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{ struct configfs_dirent * sd; list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { if (sd->s_element) { const unsigned char *existing = configfs_get_name(sd); if (strcmp(existing, new)) continue; else return -EEXIST; } } return 0; } |
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int configfs_make_dirent(struct configfs_dirent * parent_sd, struct dentry * dentry, void * element, umode_t mode, int type) { struct configfs_dirent * sd; |
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sd = configfs_new_dirent(parent_sd, element, type); |
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if (IS_ERR(sd)) return PTR_ERR(sd); |
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sd->s_mode = mode; |
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sd->s_dentry = dentry; if (dentry) { dentry->d_fsdata = configfs_get(sd); dentry->d_op = &configfs_dentry_ops; } return 0; } static int init_dir(struct inode * inode) { inode->i_op = &configfs_dir_inode_operations; inode->i_fop = &configfs_dir_operations; /* directory inodes start off with i_nlink == 2 (for "." entry) */ |
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inc_nlink(inode); |
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return 0; } |
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static int configfs_init_file(struct inode * inode) |
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{ inode->i_size = PAGE_SIZE; inode->i_fop = &configfs_file_operations; return 0; } static int init_symlink(struct inode * inode) { inode->i_op = &configfs_symlink_inode_operations; return 0; } static int create_dir(struct config_item * k, struct dentry * p, struct dentry * d) { int error; umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
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error = configfs_dirent_exists(p->d_fsdata, d->d_name.name); if (!error) error = configfs_make_dirent(p->d_fsdata, d, k, mode, |
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CONFIGFS_DIR | CONFIGFS_USET_CREATING); |
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if (!error) { |
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configfs_set_dir_dirent_depth(p->d_fsdata, d->d_fsdata); |
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error = configfs_create(d, mode, init_dir); |
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if (!error) { |
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inc_nlink(p->d_inode); |
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(d)->d_op = &configfs_dentry_ops; |
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} else { struct configfs_dirent *sd = d->d_fsdata; if (sd) { |
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spin_lock(&configfs_dirent_lock); |
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list_del_init(&sd->s_sibling); |
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spin_unlock(&configfs_dirent_lock); |
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configfs_put(sd); } |
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} } return error; } /** * configfs_create_dir - create a directory for an config_item. * @item: config_itemwe're creating directory for. * @dentry: config_item's dentry. |
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* * Note: user-created entries won't be allowed under this new directory * until it is validated by configfs_dir_set_ready() |
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*/ static int configfs_create_dir(struct config_item * item, struct dentry *dentry) { struct dentry * parent; int error = 0; BUG_ON(!item); if (item->ci_parent) parent = item->ci_parent->ci_dentry; else if (configfs_mount && configfs_mount->mnt_sb) parent = configfs_mount->mnt_sb->s_root; else return -EFAULT; error = create_dir(item,parent,dentry); if (!error) item->ci_dentry = dentry; return error; } |
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/* * Allow userspace to create new entries under a new directory created with * configfs_create_dir(), and under all of its chidlren directories recursively. * @sd configfs_dirent of the new directory to validate * * Caller must hold configfs_dirent_lock. */ static void configfs_dir_set_ready(struct configfs_dirent *sd) { struct configfs_dirent *child_sd; sd->s_type &= ~CONFIGFS_USET_CREATING; list_for_each_entry(child_sd, &sd->s_children, s_sibling) if (child_sd->s_type & CONFIGFS_USET_CREATING) configfs_dir_set_ready(child_sd); } /* * Check that a directory does not belong to a directory hierarchy being * attached and not validated yet. * @sd configfs_dirent of the directory to check * * @return non-zero iff the directory was validated * * Note: takes configfs_dirent_lock, so the result may change from false to true * in two consecutive calls, but never from true to false. */ int configfs_dirent_is_ready(struct configfs_dirent *sd) { int ret; spin_lock(&configfs_dirent_lock); ret = !(sd->s_type & CONFIGFS_USET_CREATING); spin_unlock(&configfs_dirent_lock); return ret; } |
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int configfs_create_link(struct configfs_symlink *sl, struct dentry *parent, struct dentry *dentry) { int err = 0; umode_t mode = S_IFLNK | S_IRWXUGO; |
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err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode, CONFIGFS_ITEM_LINK); |
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if (!err) { |
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err = configfs_create(dentry, mode, init_symlink); |
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if (!err) dentry->d_op = &configfs_dentry_ops; |
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else { struct configfs_dirent *sd = dentry->d_fsdata; if (sd) { |
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spin_lock(&configfs_dirent_lock); |
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list_del_init(&sd->s_sibling); |
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spin_unlock(&configfs_dirent_lock); |
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configfs_put(sd); } } |
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} return err; } static void remove_dir(struct dentry * d) { struct dentry * parent = dget(d->d_parent); struct configfs_dirent * sd; sd = d->d_fsdata; |
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spin_lock(&configfs_dirent_lock); |
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list_del_init(&sd->s_sibling); |
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spin_unlock(&configfs_dirent_lock); |
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configfs_put(sd); if (d->d_inode) simple_rmdir(parent->d_inode,d); pr_debug(" o %s removing done (%d) ",d->d_name.name, atomic_read(&d->d_count)); dput(parent); } /** * configfs_remove_dir - remove an config_item's directory. * @item: config_item we're removing. * * The only thing special about this is that we remove any files in * the directory before we remove the directory, and we've inlined * what used to be configfs_rmdir() below, instead of calling separately. |
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* * Caller holds the mutex of the item's inode |
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*/ static void configfs_remove_dir(struct config_item * item) { struct dentry * dentry = dget(item->ci_dentry); if (!dentry) return; remove_dir(dentry); /** * Drop reference from dget() on entrance. */ dput(dentry); } /* attaches attribute's configfs_dirent to the dentry corresponding to the * attribute file */ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry) { struct configfs_attribute * attr = sd->s_element; int error; |
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dentry->d_fsdata = configfs_get(sd); sd->s_dentry = dentry; |
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error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, configfs_init_file); |
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if (error) { configfs_put(sd); |
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return error; |
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} |
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dentry->d_op = &configfs_dentry_ops; |
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d_rehash(dentry); return 0; } static struct dentry * configfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata; struct configfs_dirent * sd; int found = 0; |
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int err; /* * Fake invisibility if dir belongs to a group/default groups hierarchy * being attached * * This forbids userspace to read/write attributes of items which may * not complete their initialization, since the dentries of the * attributes won't be instantiated. */ err = -ENOENT; if (!configfs_dirent_is_ready(parent_sd)) goto out; |
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list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { if (sd->s_type & CONFIGFS_NOT_PINNED) { const unsigned char * name = configfs_get_name(sd); if (strcmp(name, dentry->d_name.name)) continue; found = 1; err = configfs_attach_attr(sd, dentry); break; } } if (!found) { /* * If it doesn't exist and it isn't a NOT_PINNED item, * it must be negative. */ return simple_lookup(dir, dentry, nd); } |
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out: |
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return ERR_PTR(err); } /* * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are |
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* attributes and are removed by rmdir(). We recurse, setting * CONFIGFS_USET_DROPPING on all children that are candidates for * default detach. * If there is an error, the caller will reset the flags via * configfs_detach_rollback(). |
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*/ |
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static int configfs_detach_prep(struct dentry *dentry, struct mutex **wait_mutex) |
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{ struct configfs_dirent *parent_sd = dentry->d_fsdata; struct configfs_dirent *sd; int ret; |
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/* Mark that we're trying to drop the group */ parent_sd->s_type |= CONFIGFS_USET_DROPPING; |
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ret = -EBUSY; if (!list_empty(&parent_sd->s_links)) goto out; ret = 0; list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { |
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if (!sd->s_element || (sd->s_type & CONFIGFS_NOT_PINNED)) |
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continue; if (sd->s_type & CONFIGFS_USET_DEFAULT) { |
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/* Abort if racing with mkdir() */ if (sd->s_type & CONFIGFS_USET_IN_MKDIR) { if (wait_mutex) *wait_mutex = &sd->s_dentry->d_inode->i_mutex; return -EAGAIN; } |
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/* * Yup, recursive. If there's a problem, blame * deep nesting of default_groups */ |
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ret = configfs_detach_prep(sd->s_dentry, wait_mutex); |
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if (!ret) |
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continue; |
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} else ret = -ENOTEMPTY; break; } out: return ret; } /* |
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* Walk the tree, resetting CONFIGFS_USET_DROPPING wherever it was |
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* set. */ static void configfs_detach_rollback(struct dentry *dentry) { struct configfs_dirent *parent_sd = dentry->d_fsdata; struct configfs_dirent *sd; |
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parent_sd->s_type &= ~CONFIGFS_USET_DROPPING; list_for_each_entry(sd, &parent_sd->s_children, s_sibling) if (sd->s_type & CONFIGFS_USET_DEFAULT) |
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configfs_detach_rollback(sd->s_dentry); |
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} static void detach_attrs(struct config_item * item) { struct dentry * dentry = dget(item->ci_dentry); struct configfs_dirent * parent_sd; struct configfs_dirent * sd, * tmp; if (!dentry) return; pr_debug("configfs %s: dropping attrs for dir ", dentry->d_name.name); parent_sd = dentry->d_fsdata; list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED)) continue; |
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spin_lock(&configfs_dirent_lock); |
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list_del_init(&sd->s_sibling); |
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spin_unlock(&configfs_dirent_lock); |
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configfs_drop_dentry(sd, dentry); configfs_put(sd); } /** * Drop reference from dget() on entrance. */ dput(dentry); } static int populate_attrs(struct config_item *item) { struct config_item_type *t = item->ci_type; struct configfs_attribute *attr; int error = 0; int i; if (!t) return -EINVAL; if (t->ct_attrs) { for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) { if ((error = configfs_create_file(item, attr))) break; } } if (error) detach_attrs(item); return error; } static int configfs_attach_group(struct config_item *parent_item, struct config_item *item, struct dentry *dentry); static void configfs_detach_group(struct config_item *item); static void detach_groups(struct config_group *group) { struct dentry * dentry = dget(group->cg_item.ci_dentry); struct dentry *child; struct configfs_dirent *parent_sd; struct configfs_dirent *sd, *tmp; if (!dentry) return; parent_sd = dentry->d_fsdata; list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { if (!sd->s_element || !(sd->s_type & CONFIGFS_USET_DEFAULT)) continue; child = sd->s_dentry; |
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mutex_lock(&child->d_inode->i_mutex); |
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configfs_detach_group(sd->s_element); child->d_inode->i_flags |= S_DEAD; |
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mutex_unlock(&child->d_inode->i_mutex); |
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d_delete(child); dput(child); } /** * Drop reference from dget() on entrance. */ dput(dentry); } /* * This fakes mkdir(2) on a default_groups[] entry. It * creates a dentry, attachs it, and then does fixup * on the sd->s_type. * * We could, perhaps, tweak our parent's ->mkdir for a minute and * try using vfs_mkdir. Just a thought. */ static int create_default_group(struct config_group *parent_group, struct config_group *group) { int ret; struct qstr name; struct configfs_dirent *sd; /* We trust the caller holds a reference to parent */ struct dentry *child, *parent = parent_group->cg_item.ci_dentry; if (!group->cg_item.ci_name) group->cg_item.ci_name = group->cg_item.ci_namebuf; name.name = group->cg_item.ci_name; name.len = strlen(name.name); name.hash = full_name_hash(name.name, name.len); ret = -ENOMEM; child = d_alloc(parent, &name); if (child) { d_add(child, NULL); ret = configfs_attach_group(&parent_group->cg_item, &group->cg_item, child); if (!ret) { sd = child->d_fsdata; sd->s_type |= CONFIGFS_USET_DEFAULT; } else { d_delete(child); dput(child); } } return ret; } static int populate_groups(struct config_group *group) { struct config_group *new_group; |
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int ret = 0; int i; |
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if (group->default_groups) { |
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for (i = 0; group->default_groups[i]; i++) { new_group = group->default_groups[i]; ret = create_default_group(group, new_group); |
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|
694 695 |
if (ret) { detach_groups(group); |
7063fbf22
|
696 |
break; |
2e2ce171c
|
697 |
} |
7063fbf22
|
698 |
} |
7063fbf22
|
699 |
} |
7063fbf22
|
700 701 702 703 704 |
return ret; } /* * All of link_obj/unlink_obj/link_group/unlink_group require that |
e6bd07aee
|
705 |
* subsys->su_mutex is held. |
7063fbf22
|
706 707 708 709 710 711 712 713 714 715 716 717 |
*/ static void unlink_obj(struct config_item *item) { struct config_group *group; group = item->ci_group; if (group) { list_del_init(&item->ci_entry); item->ci_group = NULL; item->ci_parent = NULL; |
eed7a0db4
|
718 719 |
/* Drop the reference for ci_entry */ |
7063fbf22
|
720 |
config_item_put(item); |
eed7a0db4
|
721 |
/* Drop the reference for ci_parent */ |
7063fbf22
|
722 723 724 725 726 727 |
config_group_put(group); } } static void link_obj(struct config_item *parent_item, struct config_item *item) { |
eed7a0db4
|
728 729 730 731 |
/* * Parent seems redundant with group, but it makes certain * traversals much nicer. */ |
7063fbf22
|
732 |
item->ci_parent = parent_item; |
eed7a0db4
|
733 734 735 736 737 |
/* * We hold a reference on the parent for the child's ci_parent * link. */ |
7063fbf22
|
738 739 |
item->ci_group = config_group_get(to_config_group(parent_item)); list_add_tail(&item->ci_entry, &item->ci_group->cg_children); |
eed7a0db4
|
740 741 742 743 |
/* * We hold a reference on the child for ci_entry on the parent's * cg_children */ |
7063fbf22
|
744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 |
config_item_get(item); } static void unlink_group(struct config_group *group) { int i; struct config_group *new_group; if (group->default_groups) { for (i = 0; group->default_groups[i]; i++) { new_group = group->default_groups[i]; unlink_group(new_group); } } group->cg_subsys = NULL; unlink_obj(&group->cg_item); } static void link_group(struct config_group *parent_group, struct config_group *group) { int i; struct config_group *new_group; struct configfs_subsystem *subsys = NULL; /* gcc is a turd */ link_obj(&parent_group->cg_item, &group->cg_item); if (parent_group->cg_subsys) subsys = parent_group->cg_subsys; else if (configfs_is_root(&parent_group->cg_item)) subsys = to_configfs_subsystem(group); else BUG(); group->cg_subsys = subsys; if (group->default_groups) { for (i = 0; group->default_groups[i]; i++) { new_group = group->default_groups[i]; link_group(group, new_group); } } } /* * The goal is that configfs_attach_item() (and * configfs_attach_group()) can be called from either the VFS or this * module. That is, they assume that the items have been created, * the dentry allocated, and the dcache is all ready to go. * * If they fail, they must clean up after themselves as if they * had never been called. The caller (VFS or local function) will * handle cleaning up the dcache bits. * * configfs_detach_group() and configfs_detach_item() behave similarly on * the way out. They assume that the proper semaphores are held, they * clean up the configfs items, and they expect their callers will * handle the dcache bits. */ static int configfs_attach_item(struct config_item *parent_item, struct config_item *item, struct dentry *dentry) { int ret; ret = configfs_create_dir(item, dentry); if (!ret) { ret = populate_attrs(item); if (ret) { |
2e2ce171c
|
812 813 814 815 816 817 |
/* * We are going to remove an inode and its dentry but * the VFS may already have hit and used them. Thus, * we must lock them as rmdir() would. */ mutex_lock(&dentry->d_inode->i_mutex); |
7063fbf22
|
818 |
configfs_remove_dir(item); |
2e2ce171c
|
819 820 |
dentry->d_inode->i_flags |= S_DEAD; mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf22
|
821 822 823 824 825 826 |
d_delete(dentry); } } return ret; } |
2e2ce171c
|
827 |
/* Caller holds the mutex of the item's inode */ |
7063fbf22
|
828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 |
static void configfs_detach_item(struct config_item *item) { detach_attrs(item); configfs_remove_dir(item); } static int configfs_attach_group(struct config_item *parent_item, struct config_item *item, struct dentry *dentry) { int ret; struct configfs_dirent *sd; ret = configfs_attach_item(parent_item, item, dentry); if (!ret) { sd = dentry->d_fsdata; sd->s_type |= CONFIGFS_USET_DIR; |
2e2ce171c
|
845 846 847 848 849 850 851 852 853 854 |
/* * FYI, we're faking mkdir in populate_groups() * We must lock the group's inode to avoid races with the VFS * which can already hit the inode and try to add/remove entries * under it. * * We must also lock the inode to remove it safely in case of * error, as rmdir() would. */ mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); |
e74cc06df
|
855 |
configfs_adjust_dir_dirent_depth_before_populate(sd); |
7063fbf22
|
856 857 858 |
ret = populate_groups(to_config_group(item)); if (ret) { configfs_detach_item(item); |
2e2ce171c
|
859 |
dentry->d_inode->i_flags |= S_DEAD; |
7063fbf22
|
860 |
} |
e74cc06df
|
861 |
configfs_adjust_dir_dirent_depth_after_populate(sd); |
2e2ce171c
|
862 863 864 |
mutex_unlock(&dentry->d_inode->i_mutex); if (ret) d_delete(dentry); |
7063fbf22
|
865 866 867 868 |
} return ret; } |
2e2ce171c
|
869 |
/* Caller holds the mutex of the group's inode */ |
7063fbf22
|
870 871 872 873 874 875 876 |
static void configfs_detach_group(struct config_item *item) { detach_groups(to_config_group(item)); configfs_detach_item(item); } /* |
299894cc9
|
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 |
* After the item has been detached from the filesystem view, we are * ready to tear it out of the hierarchy. Notify the client before * we do that so they can perform any cleanup that requires * navigating the hierarchy. A client does not need to provide this * callback. The subsystem semaphore MUST be held by the caller, and * references must be valid for both items. It also assumes the * caller has validated ci_type. */ static void client_disconnect_notify(struct config_item *parent_item, struct config_item *item) { struct config_item_type *type; type = parent_item->ci_type; BUG_ON(!type); if (type->ct_group_ops && type->ct_group_ops->disconnect_notify) type->ct_group_ops->disconnect_notify(to_config_group(parent_item), item); } /* |
7063fbf22
|
899 900 901 902 903 904 905 906 907 908 909 910 |
* Drop the initial reference from make_item()/make_group() * This function assumes that reference is held on item * and that item holds a valid reference to the parent. Also, it * assumes the caller has validated ci_type. */ static void client_drop_item(struct config_item *parent_item, struct config_item *item) { struct config_item_type *type; type = parent_item->ci_type; BUG_ON(!type); |
eed7a0db4
|
911 912 913 914 |
/* * If ->drop_item() exists, it is responsible for the * config_item_put(). */ |
7063fbf22
|
915 916 |
if (type->ct_group_ops && type->ct_group_ops->drop_item) type->ct_group_ops->drop_item(to_config_group(parent_item), |
299894cc9
|
917 |
item); |
7063fbf22
|
918 919 920 |
else config_item_put(item); } |
631d1feba
|
921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 |
#ifdef DEBUG static void configfs_dump_one(struct configfs_dirent *sd, int level) { printk(KERN_INFO "%*s\"%s\": ", level, " ", configfs_get_name(sd)); #define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s ", level, " ", #_type); type_print(CONFIGFS_ROOT); type_print(CONFIGFS_DIR); type_print(CONFIGFS_ITEM_ATTR); type_print(CONFIGFS_ITEM_LINK); type_print(CONFIGFS_USET_DIR); type_print(CONFIGFS_USET_DEFAULT); type_print(CONFIGFS_USET_DROPPING); #undef type_print } static int configfs_dump(struct configfs_dirent *sd, int level) { struct configfs_dirent *child_sd; int ret = 0; configfs_dump_one(sd, level); if (!(sd->s_type & (CONFIGFS_DIR|CONFIGFS_ROOT))) return 0; list_for_each_entry(child_sd, &sd->s_children, s_sibling) { ret = configfs_dump(child_sd, level + 2); if (ret) break; } return ret; } #endif /* * configfs_depend_item() and configfs_undepend_item() * * WARNING: Do not call these from a configfs callback! * * This describes these functions and their helpers. * * Allow another kernel system to depend on a config_item. If this * happens, the item cannot go away until the dependant can live without * it. The idea is to give client modules as simple an interface as * possible. When a system asks them to depend on an item, they just * call configfs_depend_item(). If the item is live and the client * driver is in good shape, we'll happily do the work for them. * * Why is the locking complex? Because configfs uses the VFS to handle * all locking, but this function is called outside the normal * VFS->configfs path. So it must take VFS locks to prevent the * VFS->configfs stuff (configfs_mkdir(), configfs_rmdir(), etc). This is * why you can't call these functions underneath configfs callbacks. * * Note, btw, that this can be called at *any* time, even when a configfs * subsystem isn't registered, or when configfs is loading or unloading. * Just like configfs_register_subsystem(). So we take the same |
420118caa
|
983 984 |
* precautions. We pin the filesystem. We lock configfs_dirent_lock. * If we can find the target item in the |
631d1feba
|
985 |
* configfs tree, it must be part of the subsystem tree as well, so we |
420118caa
|
986 987 |
* do not need the subsystem semaphore. Holding configfs_dirent_lock helps * locking out mkdir() and rmdir(), who might be racing us. |
631d1feba
|
988 989 990 991 992 993 994 995 996 997 998 999 |
*/ /* * configfs_depend_prep() * * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are * attributes. This is similar but not the same to configfs_detach_prep(). * Note that configfs_detach_prep() expects the parent to be locked when it * is called, but we lock the parent *inside* configfs_depend_prep(). We * do that so we can unlock it if we find nothing. * * Here we do a depth-first search of the dentry hierarchy looking for |
420118caa
|
1000 1001 1002 1003 1004 1005 1006 1007 1008 |
* our object. * We deliberately ignore items tagged as dropping since they are virtually * dead, as well as items in the middle of attachment since they virtually * do not exist yet. This completes the locking out of racing mkdir() and * rmdir(). * Note: subdirectories in the middle of attachment start with s_type = * CONFIGFS_DIR|CONFIGFS_USET_CREATING set by create_dir(). When * CONFIGFS_USET_CREATING is set, we ignore the item. The actual set of * s_type is in configfs_new_dirent(), which has configfs_dirent_lock. |
631d1feba
|
1009 |
* |
420118caa
|
1010 |
* If the target is not found, -ENOENT is bubbled up. |
631d1feba
|
1011 1012 1013 |
* * This adds a requirement that all config_items be unique! * |
420118caa
|
1014 |
* This is recursive. There isn't |
631d1feba
|
1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 |
* much on the stack, though, so folks that need this function - be careful * about your stack! Patches will be accepted to make it iterative. */ static int configfs_depend_prep(struct dentry *origin, struct config_item *target) { struct configfs_dirent *child_sd, *sd = origin->d_fsdata; int ret = 0; BUG_ON(!origin || !sd); |
631d1feba
|
1025 1026 1027 1028 |
if (sd->s_element == target) /* Boo-yah */ goto out; list_for_each_entry(child_sd, &sd->s_children, s_sibling) { |
420118caa
|
1029 1030 1031 |
if ((child_sd->s_type & CONFIGFS_DIR) && !(child_sd->s_type & CONFIGFS_USET_DROPPING) && !(child_sd->s_type & CONFIGFS_USET_CREATING)) { |
631d1feba
|
1032 1033 1034 1035 1036 1037 1038 1039 |
ret = configfs_depend_prep(child_sd->s_dentry, target); if (!ret) goto out; /* Child path boo-yah */ } } /* We looped all our children and didn't find target */ |
631d1feba
|
1040 1041 1042 1043 1044 |
ret = -ENOENT; out: return ret; } |
631d1feba
|
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 |
int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target) { int ret; struct configfs_dirent *p, *root_sd, *subsys_sd = NULL; struct config_item *s_item = &subsys->su_group.cg_item; /* * Pin the configfs filesystem. This means we can safely access * the root of the configfs filesystem. */ ret = configfs_pin_fs(); if (ret) return ret; /* * Next, lock the root directory. We're going to check that the * subsystem is really registered, and so we need to lock out * configfs_[un]register_subsystem(). */ mutex_lock(&configfs_sb->s_root->d_inode->i_mutex); root_sd = configfs_sb->s_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; } } } if (!subsys_sd) { ret = -ENOENT; goto out_unlock_fs; } /* Ok, now we can trust subsys/s_item */ |
420118caa
|
1084 1085 |
spin_lock(&configfs_dirent_lock); /* Scan the tree, return 0 if found */ |
631d1feba
|
1086 1087 |
ret = configfs_depend_prep(subsys_sd->s_dentry, target); if (ret) |
420118caa
|
1088 |
goto out_unlock_dirent_lock; |
631d1feba
|
1089 |
|
420118caa
|
1090 1091 1092 1093 |
/* * We are sure that the item is not about to be removed by rmdir(), and * not in the middle of attachment by mkdir(). */ |
631d1feba
|
1094 1095 |
p = target->ci_dentry->d_fsdata; p->s_dependent_count += 1; |
420118caa
|
1096 1097 |
out_unlock_dirent_lock: spin_unlock(&configfs_dirent_lock); |
631d1feba
|
1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 |
out_unlock_fs: mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); /* * If we succeeded, the fs is pinned via other methods. If not, * we're done with it anyway. So release_fs() is always right. */ configfs_release_fs(); return ret; } EXPORT_SYMBOL(configfs_depend_item); /* * Release the dependent linkage. This is much simpler than * 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) { struct configfs_dirent *sd; /* |
420118caa
|
1122 1123 |
* Since we can trust everything is pinned, we just need * configfs_dirent_lock. |
631d1feba
|
1124 |
*/ |
420118caa
|
1125 |
spin_lock(&configfs_dirent_lock); |
631d1feba
|
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 |
sd = target->ci_dentry->d_fsdata; BUG_ON(sd->s_dependent_count < 1); sd->s_dependent_count -= 1; /* * After this unlock, we cannot trust the item to stay alive! * DO NOT REFERENCE item after this unlock. */ |
420118caa
|
1136 |
spin_unlock(&configfs_dirent_lock); |
631d1feba
|
1137 1138 |
} EXPORT_SYMBOL(configfs_undepend_item); |
7063fbf22
|
1139 1140 1141 |
static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { |
a6795e9eb
|
1142 1143 1144 1145 |
int ret = 0; int module_got = 0; struct config_group *group = NULL; struct config_item *item = NULL; |
7063fbf22
|
1146 1147 1148 1149 |
struct config_item *parent_item; struct configfs_subsystem *subsys; struct configfs_dirent *sd; struct config_item_type *type; |
70526b674
|
1150 |
struct module *subsys_owner = NULL, *new_item_owner = NULL; |
7063fbf22
|
1151 |
char *name; |
84efad1a5
|
1152 1153 1154 1155 |
if (dentry->d_parent == configfs_sb->s_root) { ret = -EPERM; goto out; } |
7063fbf22
|
1156 1157 |
sd = dentry->d_parent->d_fsdata; |
2a109f2a4
|
1158 1159 1160 1161 1162 1163 1164 1165 1166 |
/* * Fake invisibility if dir belongs to a group/default groups hierarchy * being attached */ if (!configfs_dirent_is_ready(sd)) { ret = -ENOENT; goto out; } |
84efad1a5
|
1167 1168 1169 1170 |
if (!(sd->s_type & CONFIGFS_USET_DIR)) { ret = -EPERM; goto out; } |
7063fbf22
|
1171 |
|
84efad1a5
|
1172 |
/* Get a working ref for the duration of this function */ |
7063fbf22
|
1173 1174 1175 1176 1177 1178 1179 1180 |
parent_item = configfs_get_config_item(dentry->d_parent); type = parent_item->ci_type; subsys = to_config_group(parent_item)->cg_subsys; BUG_ON(!subsys); if (!type || !type->ct_group_ops || (!type->ct_group_ops->make_group && !type->ct_group_ops->make_item)) { |
84efad1a5
|
1181 1182 |
ret = -EPERM; /* Lack-of-mkdir returns -EPERM */ goto out_put; |
7063fbf22
|
1183 |
} |
70526b674
|
1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 |
/* * The subsystem may belong to a different module than the item * being created. We don't want to safely pin the new item but * fail to pin the subsystem it sits under. */ if (!subsys->su_group.cg_item.ci_type) { ret = -EINVAL; goto out_put; } subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner; if (!try_module_get(subsys_owner)) { ret = -EINVAL; goto out_put; } |
7063fbf22
|
1198 1199 |
name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL); if (!name) { |
84efad1a5
|
1200 |
ret = -ENOMEM; |
70526b674
|
1201 |
goto out_subsys_put; |
7063fbf22
|
1202 |
} |
84efad1a5
|
1203 |
|
7063fbf22
|
1204 |
snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name); |
e6bd07aee
|
1205 |
mutex_lock(&subsys->su_mutex); |
7063fbf22
|
1206 |
if (type->ct_group_ops->make_group) { |
f89ab8619
|
1207 |
group = type->ct_group_ops->make_group(to_config_group(parent_item), name); |
a6795e9eb
|
1208 1209 1210 |
if (!group) group = ERR_PTR(-ENOMEM); if (!IS_ERR(group)) { |
7063fbf22
|
1211 1212 |
link_group(to_config_group(parent_item), group); item = &group->cg_item; |
a6795e9eb
|
1213 1214 |
} else ret = PTR_ERR(group); |
7063fbf22
|
1215 |
} else { |
f89ab8619
|
1216 |
item = type->ct_group_ops->make_item(to_config_group(parent_item), name); |
a6795e9eb
|
1217 1218 1219 |
if (!item) item = ERR_PTR(-ENOMEM); if (!IS_ERR(item)) |
7063fbf22
|
1220 |
link_obj(parent_item, item); |
a6795e9eb
|
1221 1222 |
else ret = PTR_ERR(item); |
7063fbf22
|
1223 |
} |
e6bd07aee
|
1224 |
mutex_unlock(&subsys->su_mutex); |
7063fbf22
|
1225 1226 |
kfree(name); |
a6795e9eb
|
1227 |
if (ret) { |
eed7a0db4
|
1228 |
/* |
dacdd0e04
|
1229 |
* If ret != 0, then link_obj() was never called. |
eed7a0db4
|
1230 1231 |
* There are no extra references to clean up. */ |
70526b674
|
1232 |
goto out_subsys_put; |
7063fbf22
|
1233 |
} |
eed7a0db4
|
1234 1235 1236 1237 |
/* * link_obj() has been called (via link_group() for groups). * From here on out, errors must clean that up. */ |
7063fbf22
|
1238 |
type = item->ci_type; |
eed7a0db4
|
1239 1240 1241 1242 |
if (!type) { ret = -EINVAL; goto out_unlink; } |
7063fbf22
|
1243 |
|
70526b674
|
1244 1245 |
new_item_owner = type->ct_owner; if (!try_module_get(new_item_owner)) { |
eed7a0db4
|
1246 1247 1248 |
ret = -EINVAL; goto out_unlink; } |
7063fbf22
|
1249 |
|
eed7a0db4
|
1250 1251 1252 1253 1254 1255 |
/* * I hate doing it this way, but if there is * an error, module_put() probably should * happen after any cleanup. */ module_got = 1; |
6d8344bae
|
1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 |
/* * Make racing rmdir() fail if it did not tag parent with * CONFIGFS_USET_DROPPING * Note: if CONFIGFS_USET_DROPPING is already set, attach_group() will * fail and let rmdir() terminate correctly */ spin_lock(&configfs_dirent_lock); /* This will make configfs_detach_prep() fail */ sd->s_type |= CONFIGFS_USET_IN_MKDIR; spin_unlock(&configfs_dirent_lock); |
eed7a0db4
|
1266 1267 1268 1269 |
if (group) ret = configfs_attach_group(parent_item, item, dentry); else ret = configfs_attach_item(parent_item, item, dentry); |
6d8344bae
|
1270 1271 |
spin_lock(&configfs_dirent_lock); sd->s_type &= ~CONFIGFS_USET_IN_MKDIR; |
2a109f2a4
|
1272 1273 |
if (!ret) configfs_dir_set_ready(dentry->d_fsdata); |
6d8344bae
|
1274 |
spin_unlock(&configfs_dirent_lock); |
eed7a0db4
|
1275 1276 1277 |
out_unlink: if (ret) { /* Tear down everything we built up */ |
e6bd07aee
|
1278 |
mutex_lock(&subsys->su_mutex); |
299894cc9
|
1279 1280 |
client_disconnect_notify(parent_item, item); |
eed7a0db4
|
1281 1282 1283 1284 1285 |
if (group) unlink_group(group); else unlink_obj(item); client_drop_item(parent_item, item); |
299894cc9
|
1286 |
|
e6bd07aee
|
1287 |
mutex_unlock(&subsys->su_mutex); |
eed7a0db4
|
1288 1289 |
if (module_got) |
70526b674
|
1290 |
module_put(new_item_owner); |
7063fbf22
|
1291 |
} |
70526b674
|
1292 1293 1294 |
out_subsys_put: if (ret) module_put(subsys_owner); |
84efad1a5
|
1295 1296 |
out_put: /* |
eed7a0db4
|
1297 1298 1299 |
* link_obj()/link_group() took a reference from child->parent, * so the parent is safely pinned. We can drop our working * reference. |
84efad1a5
|
1300 1301 1302 1303 |
*/ config_item_put(parent_item); out: |
7063fbf22
|
1304 1305 1306 1307 1308 1309 1310 1311 1312 |
return ret; } static int configfs_rmdir(struct inode *dir, struct dentry *dentry) { struct config_item *parent_item; struct config_item *item; struct configfs_subsystem *subsys; struct configfs_dirent *sd; |
70526b674
|
1313 |
struct module *subsys_owner = NULL, *dead_item_owner = NULL; |
7063fbf22
|
1314 1315 1316 1317 1318 1319 1320 1321 |
int ret; if (dentry->d_parent == configfs_sb->s_root) return -EPERM; sd = dentry->d_fsdata; if (sd->s_type & CONFIGFS_USET_DEFAULT) return -EPERM; |
84efad1a5
|
1322 |
/* Get a working ref until we have the child */ |
7063fbf22
|
1323 1324 1325 1326 1327 1328 1329 1330 |
parent_item = configfs_get_config_item(dentry->d_parent); subsys = to_config_group(parent_item)->cg_subsys; BUG_ON(!subsys); if (!parent_item->ci_type) { config_item_put(parent_item); return -EINVAL; } |
70526b674
|
1331 1332 1333 |
/* configfs_mkdir() shouldn't have allowed this */ BUG_ON(!subsys->su_group.cg_item.ci_type); subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner; |
9a73d78cd
|
1334 1335 1336 1337 |
/* * Ensure that no racing symlink() will make detach_prep() fail while * the new link is temporarily attached */ |
6d8344bae
|
1338 1339 |
do { struct mutex *wait_mutex; |
de6bf18e9
|
1340 1341 |
mutex_lock(&configfs_symlink_mutex); spin_lock(&configfs_dirent_lock); |
420118caa
|
1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 |
/* * Here's where we check for dependents. We're protected by * configfs_dirent_lock. * If no dependent, atomically tag the item as dropping. */ ret = sd->s_dependent_count ? -EBUSY : 0; if (!ret) { ret = configfs_detach_prep(dentry, &wait_mutex); if (ret) configfs_detach_rollback(dentry); } |
de6bf18e9
|
1353 1354 1355 1356 |
spin_unlock(&configfs_dirent_lock); mutex_unlock(&configfs_symlink_mutex); if (ret) { |
6d8344bae
|
1357 1358 1359 1360 1361 1362 1363 1364 |
if (ret != -EAGAIN) { config_item_put(parent_item); return ret; } /* Wait until the racing operation terminates */ mutex_lock(wait_mutex); mutex_unlock(wait_mutex); |
6d8344bae
|
1365 1366 |
} } while (ret == -EAGAIN); |
7063fbf22
|
1367 |
|
84efad1a5
|
1368 |
/* Get a working ref for the duration of this function */ |
7063fbf22
|
1369 1370 1371 1372 1373 1374 |
item = configfs_get_config_item(dentry); /* Drop reference from above, item already holds one. */ config_item_put(parent_item); if (item->ci_type) |
70526b674
|
1375 |
dead_item_owner = item->ci_type->ct_owner; |
7063fbf22
|
1376 1377 1378 |
if (sd->s_type & CONFIGFS_USET_DIR) { configfs_detach_group(item); |
e6bd07aee
|
1379 |
mutex_lock(&subsys->su_mutex); |
299894cc9
|
1380 |
client_disconnect_notify(parent_item, item); |
7063fbf22
|
1381 1382 1383 |
unlink_group(to_config_group(item)); } else { configfs_detach_item(item); |
e6bd07aee
|
1384 |
mutex_lock(&subsys->su_mutex); |
299894cc9
|
1385 |
client_disconnect_notify(parent_item, item); |
7063fbf22
|
1386 1387 1388 1389 |
unlink_obj(item); } client_drop_item(parent_item, item); |
e6bd07aee
|
1390 |
mutex_unlock(&subsys->su_mutex); |
7063fbf22
|
1391 1392 1393 |
/* Drop our reference from above */ config_item_put(item); |
70526b674
|
1394 1395 |
module_put(dead_item_owner); module_put(subsys_owner); |
7063fbf22
|
1396 1397 1398 |
return 0; } |
754661f14
|
1399 |
const struct inode_operations configfs_dir_inode_operations = { |
7063fbf22
|
1400 1401 1402 1403 1404 |
.mkdir = configfs_mkdir, .rmdir = configfs_rmdir, .symlink = configfs_symlink, .unlink = configfs_unlink, .lookup = configfs_lookup, |
3d0f89bb1
|
1405 |
.setattr = configfs_setattr, |
7063fbf22
|
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 |
}; #if 0 int configfs_rename_dir(struct config_item * item, const char *new_name) { int error = 0; struct dentry * new_dentry, * parent; if (!strcmp(config_item_name(item), new_name)) return -EINVAL; if (!item->parent) return -EINVAL; down_write(&configfs_rename_sem); parent = item->parent->dentry; |
1b1dcc1b5
|
1422 |
mutex_lock(&parent->d_inode->i_mutex); |
7063fbf22
|
1423 1424 1425 |
new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); if (!IS_ERR(new_dentry)) { |
e7515d065
|
1426 |
if (!new_dentry->d_inode) { |
7063fbf22
|
1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 |
error = config_item_set_name(item, "%s", new_name); if (!error) { d_add(new_dentry, NULL); d_move(item->dentry, new_dentry); } else d_delete(new_dentry); } else error = -EEXIST; dput(new_dentry); } |
1b1dcc1b5
|
1438 |
mutex_unlock(&parent->d_inode->i_mutex); |
7063fbf22
|
1439 1440 1441 1442 1443 1444 1445 1446 |
up_write(&configfs_rename_sem); return error; } #endif static int configfs_dir_open(struct inode *inode, struct file *file) { |
867fa491a
|
1447 |
struct dentry * dentry = file->f_path.dentry; |
7063fbf22
|
1448 |
struct configfs_dirent * parent_sd = dentry->d_fsdata; |
2a109f2a4
|
1449 |
int err; |
7063fbf22
|
1450 |
|
1b1dcc1b5
|
1451 |
mutex_lock(&dentry->d_inode->i_mutex); |
2a109f2a4
|
1452 1453 1454 1455 1456 1457 |
/* * Fake invisibility if dir belongs to a group/default groups hierarchy * being attached */ err = -ENOENT; if (configfs_dirent_is_ready(parent_sd)) { |
420118caa
|
1458 |
file->private_data = configfs_new_dirent(parent_sd, NULL, 0); |
2a109f2a4
|
1459 1460 1461 1462 1463 |
if (IS_ERR(file->private_data)) err = PTR_ERR(file->private_data); else err = 0; } |
1b1dcc1b5
|
1464 |
mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf22
|
1465 |
|
2a109f2a4
|
1466 |
return err; |
7063fbf22
|
1467 1468 1469 1470 |
} static int configfs_dir_close(struct inode *inode, struct file *file) { |
867fa491a
|
1471 |
struct dentry * dentry = file->f_path.dentry; |
7063fbf22
|
1472 |
struct configfs_dirent * cursor = file->private_data; |
1b1dcc1b5
|
1473 |
mutex_lock(&dentry->d_inode->i_mutex); |
6f6107640
|
1474 |
spin_lock(&configfs_dirent_lock); |
7063fbf22
|
1475 |
list_del_init(&cursor->s_sibling); |
6f6107640
|
1476 |
spin_unlock(&configfs_dirent_lock); |
1b1dcc1b5
|
1477 |
mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf22
|
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 |
release_configfs_dirent(cursor); return 0; } /* Relationship between s_mode and the DT_xxx types */ static inline unsigned char dt_type(struct configfs_dirent *sd) { return (sd->s_mode >> 12) & 15; } static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir) { |
867fa491a
|
1492 |
struct dentry *dentry = filp->f_path.dentry; |
7063fbf22
|
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 |
struct configfs_dirent * parent_sd = dentry->d_fsdata; struct configfs_dirent *cursor = filp->private_data; struct list_head *p, *q = &cursor->s_sibling; ino_t ino; int i = filp->f_pos; switch (i) { case 0: ino = dentry->d_inode->i_ino; if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) break; filp->f_pos++; i++; /* fallthrough */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) break; filp->f_pos++; i++; /* fallthrough */ default: if (filp->f_pos == 2) { |
6f6107640
|
1516 |
spin_lock(&configfs_dirent_lock); |
f116629d0
|
1517 |
list_move(q, &parent_sd->s_children); |
6f6107640
|
1518 |
spin_unlock(&configfs_dirent_lock); |
7063fbf22
|
1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 |
} for (p=q->next; p!= &parent_sd->s_children; p=p->next) { struct configfs_dirent *next; const char * name; int len; next = list_entry(p, struct configfs_dirent, s_sibling); if (!next->s_element) continue; name = configfs_get_name(next); len = strlen(name); if (next->s_dentry) ino = next->s_dentry->d_inode->i_ino; else ino = iunique(configfs_sb, 2); if (filldir(dirent, name, len, filp->f_pos, ino, dt_type(next)) < 0) return 0; |
6f6107640
|
1540 |
spin_lock(&configfs_dirent_lock); |
f116629d0
|
1541 |
list_move(q, p); |
6f6107640
|
1542 |
spin_unlock(&configfs_dirent_lock); |
7063fbf22
|
1543 1544 1545 1546 1547 1548 1549 1550 1551 |
p = q; filp->f_pos++; } } return 0; } static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin) { |
867fa491a
|
1552 |
struct dentry * dentry = file->f_path.dentry; |
7063fbf22
|
1553 |
|
1b1dcc1b5
|
1554 |
mutex_lock(&dentry->d_inode->i_mutex); |
7063fbf22
|
1555 1556 1557 1558 1559 1560 1561 |
switch (origin) { case 1: offset += file->f_pos; case 0: if (offset >= 0) break; default: |
867fa491a
|
1562 |
mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
7063fbf22
|
1563 1564 1565 1566 1567 1568 1569 1570 1571 |
return -EINVAL; } if (offset != file->f_pos) { file->f_pos = offset; if (file->f_pos >= 2) { struct configfs_dirent *sd = dentry->d_fsdata; struct configfs_dirent *cursor = file->private_data; struct list_head *p; loff_t n = file->f_pos - 2; |
6f6107640
|
1572 |
spin_lock(&configfs_dirent_lock); |
7063fbf22
|
1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 |
list_del(&cursor->s_sibling); p = sd->s_children.next; while (n && p != &sd->s_children) { struct configfs_dirent *next; next = list_entry(p, struct configfs_dirent, s_sibling); if (next->s_element) n--; p = p->next; } list_add_tail(&cursor->s_sibling, p); |
6f6107640
|
1584 |
spin_unlock(&configfs_dirent_lock); |
7063fbf22
|
1585 1586 |
} } |
1b1dcc1b5
|
1587 |
mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf22
|
1588 1589 |
return offset; } |
4b6f5d20b
|
1590 |
const struct file_operations configfs_dir_operations = { |
7063fbf22
|
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 |
.open = configfs_dir_open, .release = configfs_dir_close, .llseek = configfs_dir_lseek, .read = generic_read_dir, .readdir = configfs_readdir, }; int configfs_register_subsystem(struct configfs_subsystem *subsys) { int err; struct config_group *group = &subsys->su_group; struct qstr name; struct dentry *dentry; struct configfs_dirent *sd; err = configfs_pin_fs(); if (err) return err; if (!group->cg_item.ci_name) group->cg_item.ci_name = group->cg_item.ci_namebuf; sd = configfs_sb->s_root->d_fsdata; link_group(to_config_group(sd->s_element), group); |
ba611edfe
|
1615 1616 |
mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, I_MUTEX_PARENT); |
7063fbf22
|
1617 1618 1619 1620 1621 1622 1623 |
name.name = group->cg_item.ci_name; name.len = strlen(name.name); name.hash = full_name_hash(name.name, name.len); err = -ENOMEM; dentry = d_alloc(configfs_sb->s_root, &name); |
afdf04ea0
|
1624 1625 |
if (dentry) { d_add(dentry, NULL); |
7063fbf22
|
1626 |
|
afdf04ea0
|
1627 1628 1629 1630 1631 |
err = configfs_attach_group(sd->s_element, &group->cg_item, dentry); if (err) { d_delete(dentry); dput(dentry); |
2a109f2a4
|
1632 1633 1634 1635 |
} else { spin_lock(&configfs_dirent_lock); configfs_dir_set_ready(dentry->d_fsdata); spin_unlock(&configfs_dirent_lock); |
afdf04ea0
|
1636 1637 |
} } |
7063fbf22
|
1638 |
|
1b1dcc1b5
|
1639 |
mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); |
7063fbf22
|
1640 |
|
afdf04ea0
|
1641 1642 1643 |
if (err) { unlink_group(group); configfs_release_fs(); |
7063fbf22
|
1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 |
} return err; } void configfs_unregister_subsystem(struct configfs_subsystem *subsys) { struct config_group *group = &subsys->su_group; struct dentry *dentry = group->cg_item.ci_dentry; if (dentry->d_parent != configfs_sb->s_root) { printk(KERN_ERR "configfs: Tried to unregister non-subsystem! "); return; } |
55ed16029
|
1659 1660 1661 |
mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, I_MUTEX_PARENT); mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); |
9a73d78cd
|
1662 |
mutex_lock(&configfs_symlink_mutex); |
b3e76af87
|
1663 |
spin_lock(&configfs_dirent_lock); |
6d8344bae
|
1664 |
if (configfs_detach_prep(dentry, NULL)) { |
7063fbf22
|
1665 1666 1667 |
printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem! "); } |
b3e76af87
|
1668 |
spin_unlock(&configfs_dirent_lock); |
9a73d78cd
|
1669 |
mutex_unlock(&configfs_symlink_mutex); |
7063fbf22
|
1670 1671 |
configfs_detach_group(&group->cg_item); dentry->d_inode->i_flags |= S_DEAD; |
1b1dcc1b5
|
1672 |
mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf22
|
1673 1674 |
d_delete(dentry); |
1b1dcc1b5
|
1675 |
mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); |
7063fbf22
|
1676 1677 1678 1679 1680 1681 1682 1683 1684 |
dput(dentry); unlink_group(group); configfs_release_fs(); } EXPORT_SYMBOL(configfs_register_subsystem); EXPORT_SYMBOL(configfs_unregister_subsystem); |