diff options
Diffstat (limited to 'fs/configfs')
| -rw-r--r-- | fs/configfs/Kconfig | 11 | ||||
| -rw-r--r-- | fs/configfs/configfs_internal.h | 23 | ||||
| -rw-r--r-- | fs/configfs/dir.c | 461 | ||||
| -rw-r--r-- | fs/configfs/file.c | 2 | ||||
| -rw-r--r-- | fs/configfs/inode.c | 133 | ||||
| -rw-r--r-- | fs/configfs/item.c | 60 | ||||
| -rw-r--r-- | fs/configfs/mount.c | 65 | ||||
| -rw-r--r-- | fs/configfs/symlink.c | 19 |
8 files changed, 443 insertions, 331 deletions
diff --git a/fs/configfs/Kconfig b/fs/configfs/Kconfig new file mode 100644 index 00000000000..9febcdefdfd --- /dev/null +++ b/fs/configfs/Kconfig @@ -0,0 +1,11 @@ +config CONFIGFS_FS + tristate "Userspace-driven configuration filesystem" + select SYSFS + help + configfs is a RAM-based filesystem that provides the converse + of sysfs's functionality. Where sysfs is a filesystem-based + view of kernel objects, configfs is a filesystem-based manager + of kernel objects, or config_items. + + Both sysfs and configfs can and should exist together on the + same system. One is not a replacement for the other. diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index 762d287123c..bd4a3c16709 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -24,6 +24,12 @@ * configfs Copyright (C) 2005 Oracle. All rights reserved. */ +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/slab.h> #include <linux/list.h> #include <linux/spinlock.h> @@ -39,6 +45,9 @@ struct configfs_dirent { umode_t s_mode; struct dentry * s_dentry; struct iattr * s_iattr; +#ifdef CONFIG_LOCKDEP + int s_depth; +#endif }; #define CONFIGFS_ROOT 0x0001 @@ -55,13 +64,12 @@ struct configfs_dirent { extern struct mutex configfs_symlink_mutex; extern spinlock_t configfs_dirent_lock; -extern struct vfsmount * configfs_mount; extern struct kmem_cache *configfs_dir_cachep; extern int configfs_is_root(struct config_item *item); -extern struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent *); -extern int configfs_create(struct dentry *, int mode, int (*init)(struct inode *)); +extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *); +extern int configfs_create(struct dentry *, umode_t mode, int (*init)(struct inode *)); extern int configfs_inode_init(void); extern void configfs_inode_exit(void); @@ -77,16 +85,17 @@ extern const unsigned char * configfs_get_name(struct configfs_dirent *sd); extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent); extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr); -extern int configfs_pin_fs(void); +extern struct dentry *configfs_pin_fs(void); extern void configfs_release_fs(void); extern struct rw_semaphore configfs_rename_sem; -extern struct super_block * configfs_sb; extern const struct file_operations configfs_dir_operations; extern const struct file_operations configfs_file_operations; extern const struct file_operations bin_fops; extern const struct inode_operations configfs_dir_inode_operations; +extern const struct inode_operations configfs_root_inode_operations; extern const struct inode_operations configfs_symlink_inode_operations; +extern const struct dentry_operations configfs_dentry_ops; extern int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname); @@ -117,7 +126,7 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry { struct config_item * item = NULL; - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); if (!d_unhashed(dentry)) { struct configfs_dirent * sd = dentry->d_fsdata; if (sd->s_type & CONFIGFS_ITEM_LINK) { @@ -126,7 +135,7 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry } else item = config_item_get(sd->s_element); } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); return item; } diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 8e93341f3e8..668dcabc569 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -53,36 +53,124 @@ DEFINE_SPINLOCK(configfs_dirent_lock); static void configfs_d_iput(struct dentry * dentry, struct inode * inode) { - struct configfs_dirent * sd = dentry->d_fsdata; + struct configfs_dirent *sd = dentry->d_fsdata; if (sd) { - BUG_ON(sd->s_dentry != dentry); - sd->s_dentry = NULL; + /* Coordinate with configfs_readdir */ + spin_lock(&configfs_dirent_lock); + /* Coordinate with configfs_attach_attr where will increase + * sd->s_count and update sd->s_dentry to new allocated one. + * Only set sd->dentry to null when this dentry is the only + * sd owner. + * If not do so, configfs_d_iput may run just after + * configfs_attach_attr and set sd->s_dentry to null + * even it's still in use. + */ + if (atomic_read(&sd->s_count) <= 2) + sd->s_dentry = NULL; + + spin_unlock(&configfs_dirent_lock); configfs_put(sd); } iput(inode); } +const struct dentry_operations configfs_dentry_ops = { + .d_iput = configfs_d_iput, + .d_delete = always_delete_dentry, +}; + +#ifdef CONFIG_LOCKDEP + /* - * We _must_ delete our dentries on last dput, as the chain-to-parent - * behavior is required to clear the parents of default_groups. + * 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 int configfs_d_delete(struct dentry *dentry) + +static void configfs_init_dirent_depth(struct configfs_dirent *sd) { - return 1; + sd->s_depth = -1; } -static struct dentry_operations configfs_dentry_ops = { - .d_iput = configfs_d_iput, - /* simple_delete_dentry() isn't exported */ - .d_delete = configfs_d_delete, -}; +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 */ /* * Allocates a new configfs_dirent and links it to the parent configfs_dirent */ -static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd, - void * element) +static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd, + void *element, int type) { struct configfs_dirent * sd; @@ -94,6 +182,8 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare INIT_LIST_HEAD(&sd->s_links); INIT_LIST_HEAD(&sd->s_children); sd->s_element = element; + sd->s_type = type; + configfs_init_dirent_depth(sd); spin_lock(&configfs_dirent_lock); if (parent_sd->s_type & CONFIGFS_USET_DROPPING) { spin_unlock(&configfs_dirent_lock); @@ -138,17 +228,14 @@ int configfs_make_dirent(struct configfs_dirent * parent_sd, { struct configfs_dirent * sd; - sd = configfs_new_dirent(parent_sd, element); + sd = configfs_new_dirent(parent_sd, element, type); if (IS_ERR(sd)) return PTR_ERR(sd); sd->s_mode = mode; - sd->s_type = type; sd->s_dentry = dentry; - if (dentry) { + if (dentry) dentry->d_fsdata = configfs_get(sd); - dentry->d_op = &configfs_dentry_ops; - } return 0; } @@ -176,21 +263,23 @@ static int init_symlink(struct inode * inode) return 0; } -static int create_dir(struct config_item * k, struct dentry * p, - struct dentry * d) +static int create_dir(struct config_item *k, struct dentry *d) { int error; umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; + struct dentry *p = d->d_parent; + + BUG_ON(!k); error = configfs_dirent_exists(p->d_fsdata, d->d_name.name); if (!error) error = configfs_make_dirent(p->d_fsdata, d, k, mode, CONFIGFS_DIR | CONFIGFS_USET_CREATING); if (!error) { + configfs_set_dir_dirent_depth(p->d_fsdata, d->d_fsdata); error = configfs_create(d, mode, init_dir); if (!error) { inc_nlink(p->d_inode); - (d)->d_op = &configfs_dentry_ops; } else { struct configfs_dirent *sd = d->d_fsdata; if (sd) { @@ -216,19 +305,7 @@ static int create_dir(struct config_item * k, struct dentry * p, 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); + int error = create_dir(item, dentry); if (!error) item->ci_dentry = dentry; return error; @@ -283,9 +360,7 @@ int configfs_create_link(struct configfs_symlink *sl, CONFIGFS_ITEM_LINK); if (!err) { err = configfs_create(dentry, mode, init_symlink); - if (!err) - dentry->d_op = &configfs_dentry_ops; - else { + if (err) { struct configfs_dirent *sd = dentry->d_fsdata; if (sd) { spin_lock(&configfs_dirent_lock); @@ -311,8 +386,7 @@ static void remove_dir(struct dentry * d) if (d->d_inode) simple_rmdir(parent->d_inode,d); - pr_debug(" o %s removing done (%d)\n",d->d_name.name, - atomic_read(&d->d_count)); + pr_debug(" o %s removing done (%d)\n",d->d_name.name, d_count(d)); dput(parent); } @@ -351,8 +425,11 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den struct configfs_attribute * attr = sd->s_element; int error; + spin_lock(&configfs_dirent_lock); dentry->d_fsdata = configfs_get(sd); sd->s_dentry = dentry; + spin_unlock(&configfs_dirent_lock); + error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, configfs_init_file); if (error) { @@ -360,7 +437,6 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den return error; } - dentry->d_op = &configfs_dentry_ops; d_rehash(dentry); return 0; @@ -368,7 +444,7 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den static struct dentry * configfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) + unsigned int flags) { struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata; struct configfs_dirent * sd; @@ -405,7 +481,10 @@ static struct dentry * configfs_lookup(struct inode *dir, * If it doesn't exist and it isn't a NOT_PINNED item, * it must be negative. */ - return simple_lookup(dir, dentry, nd); + if (dentry->d_name.len > NAME_MAX) + return ERR_PTR(-ENAMETOOLONG); + d_add(dentry, NULL); + return NULL; } out: @@ -557,6 +636,7 @@ static void detach_groups(struct config_group *group) configfs_detach_group(sd->s_element); child->d_inode->i_flags |= S_DEAD; + dont_mount(child); mutex_unlock(&child->d_inode->i_mutex); @@ -582,19 +662,15 @@ 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); + child = d_alloc_name(parent, group->cg_item.ci_name); if (child) { d_add(child, NULL); @@ -604,7 +680,8 @@ static int create_default_group(struct config_group *parent_group, sd = child->d_fsdata; sd->s_type |= CONFIGFS_USET_DEFAULT; } else { - d_delete(child); + BUG_ON(child->d_inode); + d_drop(child); dput(child); } } @@ -752,6 +829,7 @@ static int configfs_attach_item(struct config_item *parent_item, mutex_lock(&dentry->d_inode->i_mutex); configfs_remove_dir(item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); mutex_unlock(&dentry->d_inode->i_mutex); d_delete(dentry); } @@ -789,11 +867,14 @@ static int configfs_attach_group(struct config_item *parent_item, * error, as rmdir() would. */ mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); + configfs_adjust_dir_dirent_depth_before_populate(sd); ret = populate_groups(to_config_group(item)); if (ret) { configfs_detach_item(item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); } + configfs_adjust_dir_dirent_depth_after_populate(sd); mutex_unlock(&dentry->d_inode->i_mutex); if (ret) d_delete(dentry); @@ -859,9 +940,9 @@ static void client_drop_item(struct config_item *parent_item, #ifdef DEBUG static void configfs_dump_one(struct configfs_dirent *sd, int level) { - printk(KERN_INFO "%*s\"%s\":\n", level, " ", configfs_get_name(sd)); + pr_info("%*s\"%s\":\n", level, " ", configfs_get_name(sd)); -#define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s\n", level, " ", #_type); +#define type_print(_type) if (sd->s_type & _type) pr_info("%*s %s\n", level, " ", #_type); type_print(CONFIGFS_ROOT); type_print(CONFIGFS_DIR); type_print(CONFIGFS_ITEM_ATTR); @@ -901,7 +982,7 @@ static int configfs_dump(struct configfs_dirent *sd, int level) * 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 + * happens, the item cannot go away until the dependent 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 @@ -916,11 +997,11 @@ static int configfs_dump(struct configfs_dirent *sd, int level) * 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 - * precautions. We pin the filesystem. We lock each i_mutex _in_order_ - * on our way down the tree. If we can find the target item in the + * precautions. We pin the filesystem. We lock configfs_dirent_lock. + * If we can find the target item in the * configfs tree, it must be part of the subsystem tree as well, so we - * do not need the subsystem semaphore. Holding the i_mutex chain locks - * out mkdir() and rmdir(), who might be racing us. + * do not need the subsystem semaphore. Holding configfs_dirent_lock helps + * locking out mkdir() and rmdir(), who might be racing us. */ /* @@ -933,35 +1014,40 @@ static int configfs_dump(struct configfs_dirent *sd, int level) * do that so we can unlock it if we find nothing. * * Here we do a depth-first search of the dentry hierarchy looking for - * our object. We take i_mutex on each step of the way down. IT IS - * ESSENTIAL THAT i_mutex LOCKING IS ORDERED. If we come back up a branch, - * we'll drop the i_mutex. + * 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. * - * If the target is not found, -ENOENT is bubbled up and we have released - * all locks. If the target was found, the locks will be cleared by - * configfs_depend_rollback(). + * If the target is not found, -ENOENT is bubbled up. * * This adds a requirement that all config_items be unique! * - * This is recursive because the locking traversal is tricky. There isn't + * This is recursive. There isn't * 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; + struct configfs_dirent *child_sd, *sd; int ret = 0; - BUG_ON(!origin || !sd); + BUG_ON(!origin || !origin->d_fsdata); + sd = origin->d_fsdata; - /* Lock this guy on the way down */ - mutex_lock(&sd->s_dentry->d_inode->i_mutex); if (sd->s_element == target) /* Boo-yah */ goto out; list_for_each_entry(child_sd, &sd->s_children, s_sibling) { - if (child_sd->s_type & CONFIGFS_DIR) { + if ((child_sd->s_type & CONFIGFS_DIR) && + !(child_sd->s_type & CONFIGFS_USET_DROPPING) && + !(child_sd->s_type & CONFIGFS_USET_CREATING)) { ret = configfs_depend_prep(child_sd->s_dentry, target); if (!ret) @@ -970,56 +1056,36 @@ static int configfs_depend_prep(struct dentry *origin, } /* We looped all our children and didn't find target */ - mutex_unlock(&sd->s_dentry->d_inode->i_mutex); ret = -ENOENT; out: return ret; } -/* - * This is ONLY called if configfs_depend_prep() did its job. So we can - * trust the entire path from item back up to origin. - * - * We walk backwards from item, unlocking each i_mutex. We finish by - * unlocking origin. - */ -static void configfs_depend_rollback(struct dentry *origin, - struct config_item *item) -{ - struct dentry *dentry = item->ci_dentry; - - while (dentry != origin) { - mutex_unlock(&dentry->d_inode->i_mutex); - dentry = dentry->d_parent; - } - - mutex_unlock(&origin->d_inode->i_mutex); -} - 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; + struct dentry *root; /* * Pin the configfs filesystem. This means we can safely access * the root of the configfs filesystem. */ - ret = configfs_pin_fs(); - if (ret) - return ret; + root = configfs_pin_fs(); + if (IS_ERR(root)) + return PTR_ERR(root); /* * 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); + mutex_lock(&root->d_inode->i_mutex); - root_sd = configfs_sb->s_root->d_fsdata; + root_sd = root->d_fsdata; list_for_each_entry(p, &root_sd->s_children, s_sibling) { if (p->s_type & CONFIGFS_DIR) { @@ -1037,19 +1103,23 @@ int configfs_depend_item(struct configfs_subsystem *subsys, /* Ok, now we can trust subsys/s_item */ - /* Scan the tree, locking i_mutex recursively, return 0 if found */ + 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_fs; + goto out_unlock_dirent_lock; - /* We hold all i_mutexes from the subsystem down to the target */ + /* + * 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; - configfs_depend_rollback(subsys_sd->s_dentry, target); - +out_unlock_dirent_lock: + spin_unlock(&configfs_dirent_lock); out_unlock_fs: - mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); + mutex_unlock(&root->d_inode->i_mutex); /* * If we succeeded, the fs is pinned via other methods. If not, @@ -1072,10 +1142,10 @@ void configfs_undepend_item(struct configfs_subsystem *subsys, struct configfs_dirent *sd; /* - * Since we can trust everything is pinned, we just need i_mutex - * on the item. + * Since we can trust everything is pinned, we just need + * configfs_dirent_lock. */ - mutex_lock(&target->ci_dentry->d_inode->i_mutex); + spin_lock(&configfs_dirent_lock); sd = target->ci_dentry->d_fsdata; BUG_ON(sd->s_dependent_count < 1); @@ -1086,11 +1156,11 @@ void configfs_undepend_item(struct configfs_subsystem *subsys, * After this unlock, we cannot trust the item to stay alive! * DO NOT REFERENCE item after this unlock. */ - mutex_unlock(&target->ci_dentry->d_inode->i_mutex); + spin_unlock(&configfs_dirent_lock); } EXPORT_SYMBOL(configfs_undepend_item); -static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { int ret = 0; int module_got = 0; @@ -1103,11 +1173,6 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) struct module *subsys_owner = NULL, *new_item_owner = NULL; char *name; - if (dentry->d_parent == configfs_sb->s_root) { - ret = -EPERM; - goto out; - } - sd = dentry->d_parent->d_fsdata; /* @@ -1279,20 +1344,10 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) struct module *subsys_owner = NULL, *dead_item_owner = NULL; 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; - /* - * Here's where we check for dependents. We're protected by - * i_mutex. - */ - if (sd->s_dependent_count) - return -EBUSY; - /* Get a working ref until we have the child */ parent_item = configfs_get_config_item(dentry->d_parent); subsys = to_config_group(parent_item)->cg_subsys; @@ -1316,9 +1371,17 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) mutex_lock(&configfs_symlink_mutex); spin_lock(&configfs_dirent_lock); - ret = configfs_detach_prep(dentry, &wait_mutex); - if (ret) - configfs_detach_rollback(dentry); + /* + * 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); + } spin_unlock(&configfs_dirent_lock); mutex_unlock(&configfs_symlink_mutex); @@ -1378,6 +1441,11 @@ const struct inode_operations configfs_dir_inode_operations = { .setattr = configfs_setattr, }; +const struct inode_operations configfs_root_inode_operations = { + .lookup = configfs_lookup, + .setattr = configfs_setattr, +}; + #if 0 int configfs_rename_dir(struct config_item * item, const char *new_name) { @@ -1429,7 +1497,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file) */ err = -ENOENT; if (configfs_dirent_is_ready(parent_sd)) { - file->private_data = configfs_new_dirent(parent_sd, NULL); + file->private_data = configfs_new_dirent(parent_sd, NULL, 0); if (IS_ERR(file->private_data)) err = PTR_ERR(file->private_data); else @@ -1462,80 +1530,83 @@ 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) +static int configfs_readdir(struct file *file, struct dir_context *ctx) { - struct dentry *dentry = filp->f_path.dentry; + struct dentry *dentry = file->f_path.dentry; + struct super_block *sb = dentry->d_sb; struct configfs_dirent * parent_sd = dentry->d_fsdata; - struct configfs_dirent *cursor = filp->private_data; + struct configfs_dirent *cursor = file->private_data; struct list_head *p, *q = &cursor->s_sibling; - ino_t ino; - int i = filp->f_pos; + ino_t ino = 0; - 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) { - spin_lock(&configfs_dirent_lock); - list_move(q, &parent_sd->s_children); - spin_unlock(&configfs_dirent_lock); - } - for (p=q->next; p!= &parent_sd->s_children; p=p->next) { - struct configfs_dirent *next; - const char * name; - int len; + if (!dir_emit_dots(file, ctx)) + return 0; + if (ctx->pos == 2) { + spin_lock(&configfs_dirent_lock); + list_move(q, &parent_sd->s_children); + spin_unlock(&configfs_dirent_lock); + } + for (p = q->next; p != &parent_sd->s_children; p = p->next) { + struct configfs_dirent *next; + const char *name; + int len; + struct inode *inode = NULL; + + next = list_entry(p, struct configfs_dirent, s_sibling); + if (!next->s_element) + continue; - next = list_entry(p, struct configfs_dirent, - s_sibling); - if (!next->s_element) - continue; + name = configfs_get_name(next); + len = strlen(name); - 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); + /* + * We'll have a dentry and an inode for + * PINNED items and for open attribute + * files. We lock here to prevent a race + * with configfs_d_iput() clearing + * s_dentry before calling iput(). + * + * Why do we go to the trouble? If + * someone has an attribute file open, + * the inode number should match until + * they close it. Beyond that, we don't + * care. + */ + spin_lock(&configfs_dirent_lock); + dentry = next->s_dentry; + if (dentry) + inode = dentry->d_inode; + if (inode) + ino = inode->i_ino; + spin_unlock(&configfs_dirent_lock); + if (!inode) + ino = iunique(sb, 2); - if (filldir(dirent, name, len, filp->f_pos, ino, - dt_type(next)) < 0) - return 0; + if (!dir_emit(ctx, name, len, ino, dt_type(next))) + return 0; - spin_lock(&configfs_dirent_lock); - list_move(q, p); - spin_unlock(&configfs_dirent_lock); - p = q; - filp->f_pos++; - } + spin_lock(&configfs_dirent_lock); + list_move(q, p); + spin_unlock(&configfs_dirent_lock); + p = q; + ctx->pos++; } return 0; } -static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin) +static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence) { struct dentry * dentry = file->f_path.dentry; mutex_lock(&dentry->d_inode->i_mutex); - switch (origin) { + switch (whence) { case 1: offset += file->f_pos; case 0: if (offset >= 0) break; default: - mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); + mutex_unlock(&file_inode(file)->i_mutex); return -EINVAL; } if (offset != file->f_pos) { @@ -1570,43 +1641,39 @@ const struct file_operations configfs_dir_operations = { .release = configfs_dir_close, .llseek = configfs_dir_lseek, .read = generic_read_dir, - .readdir = configfs_readdir, + .iterate = 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 dentry *root; struct configfs_dirent *sd; - err = configfs_pin_fs(); - if (err) - return err; + root = configfs_pin_fs(); + if (IS_ERR(root)) + return PTR_ERR(root); if (!group->cg_item.ci_name) group->cg_item.ci_name = group->cg_item.ci_namebuf; - sd = configfs_sb->s_root->d_fsdata; + sd = root->d_fsdata; link_group(to_config_group(sd->s_element), group); - mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, - I_MUTEX_PARENT); - - name.name = group->cg_item.ci_name; - name.len = strlen(name.name); - name.hash = full_name_hash(name.name, name.len); + mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT); err = -ENOMEM; - dentry = d_alloc(configfs_sb->s_root, &name); + dentry = d_alloc_name(root, group->cg_item.ci_name); if (dentry) { d_add(dentry, NULL); err = configfs_attach_group(sd->s_element, &group->cg_item, dentry); if (err) { - d_delete(dentry); + BUG_ON(dentry->d_inode); + d_drop(dentry); dput(dentry); } else { spin_lock(&configfs_dirent_lock); @@ -1615,7 +1682,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) } } - mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); + mutex_unlock(&root->d_inode->i_mutex); if (err) { unlink_group(group); @@ -1629,29 +1696,31 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) { struct config_group *group = &subsys->su_group; struct dentry *dentry = group->cg_item.ci_dentry; + struct dentry *root = dentry->d_sb->s_root; - if (dentry->d_parent != configfs_sb->s_root) { - printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n"); + if (dentry->d_parent != root) { + pr_err("Tried to unregister non-subsystem!\n"); return; } - mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, + mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT); mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); mutex_lock(&configfs_symlink_mutex); spin_lock(&configfs_dirent_lock); if (configfs_detach_prep(dentry, NULL)) { - printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n"); + pr_err("Tried to unregister non-empty subsystem!\n"); } spin_unlock(&configfs_dirent_lock); mutex_unlock(&configfs_symlink_mutex); configfs_detach_group(&group->cg_item); dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); mutex_unlock(&dentry->d_inode->i_mutex); d_delete(dentry); - mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); + mutex_unlock(&root->d_inode->i_mutex); dput(dentry); diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 2b6cb23dd14..1d1c41f1014 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -203,7 +203,7 @@ configfs_write_file(struct file *file, const char __user *buf, size_t count, lof mutex_lock(&buffer->mutex); len = fill_write_buffer(buffer, buf, count); if (len > 0) - len = flush_write_buffer(file->f_path.dentry, buffer, count); + len = flush_write_buffer(file->f_path.dentry, buffer, len); if (len > 0) *ppos += len; mutex_unlock(&buffer->mutex); diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 5d349d38e05..5946ad98053 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -23,7 +23,8 @@ * * configfs Copyright (C) 2005 Oracle. All rights reserved. * - * Please see Documentation/filesystems/configfs.txt for more information. + * Please see Documentation/filesystems/configfs/configfs.txt for more + * information. */ #undef DEBUG @@ -33,11 +34,15 @@ #include <linux/backing-dev.h> #include <linux/capability.h> #include <linux/sched.h> +#include <linux/lockdep.h> +#include <linux/slab.h> #include <linux/configfs.h> #include "configfs_internal.h" -extern struct super_block * configfs_sb; +#ifdef CONFIG_LOCKDEP +static struct lock_class_key default_group_class[MAX_LOCK_DEPTH]; +#endif static const struct address_space_operations configfs_aops = { .readpage = simple_readpage, @@ -46,6 +51,7 @@ static const struct address_space_operations configfs_aops = { }; static struct backing_dev_info configfs_backing_dev_info = { + .name = "configfs", .ra_pages = 0, /* No readahead */ .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, }; @@ -66,15 +72,6 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr) return -EINVAL; sd_iattr = sd->s_iattr; - - error = inode_change_ok(inode, iattr); - if (error) - return error; - - error = inode_setattr(inode, iattr); - if (error) - return error; - if (!sd_iattr) { /* setting attributes for the first time, allocate now */ sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL); @@ -82,14 +79,17 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr) return -ENOMEM; /* assign default attributes */ sd_iattr->ia_mode = sd->s_mode; - sd_iattr->ia_uid = 0; - sd_iattr->ia_gid = 0; + sd_iattr->ia_uid = GLOBAL_ROOT_UID; + sd_iattr->ia_gid = GLOBAL_ROOT_GID; sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME; sd->s_iattr = sd_iattr; } - /* attributes were changed atleast once in past */ + error = simple_setattr(dentry, iattr); + if (error) + return error; + if (ia_valid & ATTR_UID) sd_iattr->ia_uid = iattr->ia_uid; if (ia_valid & ATTR_GID) @@ -114,7 +114,7 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr) return error; } -static inline void set_default_inode_attr(struct inode * inode, mode_t mode) +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; @@ -130,10 +130,12 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) inode->i_ctime = iattr->ia_ctime; } -struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) +struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd, + struct super_block *s) { - struct inode * inode = new_inode(configfs_sb); + struct inode * inode = new_inode(s); if (inode) { + inode->i_ino = get_next_ino(); inode->i_mapping->a_ops = &configfs_aops; inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; inode->i_op = &configfs_inode_operations; @@ -150,38 +152,69 @@ struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) return inode; } -int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) +#ifdef CONFIG_LOCKDEP + +static void configfs_set_inode_lock_class(struct configfs_dirent *sd, + struct inode *inode) +{ + int depth = sd->s_depth; + + if (depth > 0) { + if (depth <= ARRAY_SIZE(default_group_class)) { + lockdep_set_class(&inode->i_mutex, + &default_group_class[depth - 1]); + } else { + /* + * In practice the maximum level of locking depth is + * already reached. Just inform about possible reasons. + */ + pr_info("Too many levels of inodes for the locking correctness validator.\n"); + pr_info("Spurious warnings may appear.\n"); + } + } +} + +#else /* CONFIG_LOCKDEP */ + +static void configfs_set_inode_lock_class(struct configfs_dirent *sd, + struct inode *inode) +{ +} + +#endif /* CONFIG_LOCKDEP */ + +int configfs_create(struct dentry * dentry, umode_t mode, int (*init)(struct inode *)) { int error = 0; - struct inode * inode = NULL; - if (dentry) { - if (!dentry->d_inode) { - struct configfs_dirent *sd = dentry->d_fsdata; - if ((inode = configfs_new_inode(mode, sd))) { - 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; - } - goto Proceed; - } - else - error = -ENOMEM; - } else - error = -EEXIST; - } else - error = -ENOENT; - goto Done; + struct inode *inode = NULL; + struct configfs_dirent *sd; + struct inode *p_inode; - Proceed: - if (init) + if (!dentry) + return -ENOENT; + + if (dentry->d_inode) + return -EEXIST; + + sd = dentry->d_fsdata; + inode = configfs_new_inode(mode, sd, dentry->d_sb); + if (!inode) + return -ENOMEM; + + p_inode = dentry->d_parent->d_inode; + p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; + configfs_set_inode_lock_class(sd, inode); + + if (init) { error = init(inode); - if (!error) { - d_instantiate(dentry, inode); - if (S_ISDIR(mode) || S_ISLNK(mode)) - dget(dentry); /* pin link and directory dentries in core */ - } else - iput(inode); - Done: + if (error) { + iput(inode); + return error; + } + } + d_instantiate(dentry, inode); + if (S_ISDIR(mode) || S_ISLNK(mode)) + dget(dentry); /* pin link and directory dentries in core */ return error; } @@ -215,18 +248,14 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) struct dentry * dentry = sd->s_dentry; if (dentry) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry) && dentry->d_inode)) { - dget_locked(dentry); + dget_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, dentry); - } else { + } else spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); - } } } @@ -260,7 +289,7 @@ int __init configfs_inode_init(void) return bdi_init(&configfs_backing_dev_info); } -void __exit configfs_inode_exit(void) +void configfs_inode_exit(void) { bdi_destroy(&configfs_backing_dev_info); } diff --git a/fs/configfs/item.c b/fs/configfs/item.c index 76dc4c3e5d5..e65f9ffbb99 100644 --- a/fs/configfs/item.c +++ b/fs/configfs/item.c @@ -19,11 +19,11 @@ * Boston, MA 021110-1307, USA. * * Based on kobject: - * kobject is Copyright (c) 2002-2003 Patrick Mochel + * kobject is Copyright (c) 2002-2003 Patrick Mochel * * configfs Copyright (C) 2005 Oracle. All rights reserved. * - * Please see the file Documentation/filesystems/configfs.txt for + * Please see the file Documentation/filesystems/configfs/configfs.txt for * critical information about using the config_item interface. */ @@ -35,9 +35,9 @@ #include <linux/configfs.h> -static inline struct config_item * to_item(struct list_head * entry) +static inline struct config_item *to_item(struct list_head *entry) { - return container_of(entry,struct config_item,ci_entry); + return container_of(entry, struct config_item, ci_entry); } /* Evil kernel */ @@ -47,34 +47,35 @@ static void config_item_release(struct kref *kref); * config_item_init - initialize item. * @item: item in question. */ -void config_item_init(struct config_item * item) +void config_item_init(struct config_item *item) { kref_init(&item->ci_kref); INIT_LIST_HEAD(&item->ci_entry); } +EXPORT_SYMBOL(config_item_init); /** * config_item_set_name - Set the name of an item * @item: item. - * @name: name. + * @fmt: The vsnprintf()'s format string. * * If strlen(name) >= CONFIGFS_ITEM_NAME_LEN, then use a * dynamically allocated string that @item->ci_name points to. * Otherwise, use the static @item->ci_namebuf array. */ -int config_item_set_name(struct config_item * item, const char * fmt, ...) +int config_item_set_name(struct config_item *item, const char *fmt, ...) { int error = 0; int limit = CONFIGFS_ITEM_NAME_LEN; int need; va_list args; - char * name; + char *name; /* * First, try the static array */ - va_start(args,fmt); - need = vsnprintf(item->ci_namebuf,limit,fmt,args); + va_start(args, fmt); + need = vsnprintf(item->ci_namebuf, limit, fmt, args); va_end(args); if (need < limit) name = item->ci_namebuf; @@ -83,13 +84,13 @@ int config_item_set_name(struct config_item * item, const char * fmt, ...) * Need more space? Allocate it and try again */ limit = need + 1; - name = kmalloc(limit,GFP_KERNEL); + name = kmalloc(limit, GFP_KERNEL); if (!name) { error = -ENOMEM; goto Done; } - va_start(args,fmt); - need = vsnprintf(name,limit,fmt,args); + va_start(args, fmt); + need = vsnprintf(name, limit, fmt, args); va_end(args); /* Still? Give up. */ @@ -109,7 +110,6 @@ int config_item_set_name(struct config_item * item, const char * fmt, ...) Done: return error; } - EXPORT_SYMBOL(config_item_set_name); void config_item_init_type_name(struct config_item *item, @@ -131,20 +131,21 @@ void config_group_init_type_name(struct config_group *group, const char *name, } EXPORT_SYMBOL(config_group_init_type_name); -struct config_item * config_item_get(struct config_item * item) +struct config_item *config_item_get(struct config_item *item) { if (item) kref_get(&item->ci_kref); return item; } +EXPORT_SYMBOL(config_item_get); -static void config_item_cleanup(struct config_item * item) +static void config_item_cleanup(struct config_item *item) { - struct config_item_type * t = item->ci_type; - struct config_group * s = item->ci_group; - struct config_item * parent = item->ci_parent; + struct config_item_type *t = item->ci_type; + struct config_group *s = item->ci_group; + struct config_item *parent = item->ci_parent; - pr_debug("config_item %s: cleaning up\n",config_item_name(item)); + pr_debug("config_item %s: cleaning up\n", config_item_name(item)); if (item->ci_name != item->ci_namebuf) kfree(item->ci_name); item->ci_name = NULL; @@ -167,21 +168,23 @@ static void config_item_release(struct kref *kref) * * Decrement the refcount, and if 0, call config_item_cleanup(). */ -void config_item_put(struct config_item * item) +void config_item_put(struct config_item *item) { if (item) kref_put(&item->ci_kref, config_item_release); } +EXPORT_SYMBOL(config_item_put); /** * config_group_init - initialize a group for use - * @k: group + * @group: config_group */ void config_group_init(struct config_group *group) { config_item_init(&group->cg_item); INIT_LIST_HEAD(&group->cg_children); } +EXPORT_SYMBOL(config_group_init); /** * config_group_find_item - search for item in group. @@ -195,11 +198,11 @@ void config_group_init(struct config_group *group) struct config_item *config_group_find_item(struct config_group *group, const char *name) { - struct list_head * entry; - struct config_item * ret = NULL; + struct list_head *entry; + struct config_item *ret = NULL; - list_for_each(entry,&group->cg_children) { - struct config_item * item = to_item(entry); + list_for_each(entry, &group->cg_children) { + struct config_item *item = to_item(entry); if (config_item_name(item) && !strcmp(config_item_name(item), name)) { ret = config_item_get(item); @@ -208,9 +211,4 @@ struct config_item *config_group_find_item(struct config_group *group, } return ret; } - -EXPORT_SYMBOL(config_item_init); -EXPORT_SYMBOL(config_group_init); -EXPORT_SYMBOL(config_item_get); -EXPORT_SYMBOL(config_item_put); EXPORT_SYMBOL(config_group_find_item); diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c index 8421cea7d8c..f6c28583339 100644 --- a/fs/configfs/mount.c +++ b/fs/configfs/mount.c @@ -29,6 +29,7 @@ #include <linux/mount.h> #include <linux/pagemap.h> #include <linux/init.h> +#include <linux/slab.h> #include <linux/configfs.h> #include "configfs_internal.h" @@ -36,8 +37,7 @@ /* Random magic number */ #define CONFIGFS_MAGIC 0x62656570 -struct vfsmount * configfs_mount = NULL; -struct super_block * configfs_sb = NULL; +static struct vfsmount *configfs_mount = NULL; struct kmem_cache *configfs_dir_cachep; static int configfs_mnt_count = 0; @@ -76,50 +76,51 @@ static int configfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_magic = CONFIGFS_MAGIC; sb->s_op = &configfs_ops; sb->s_time_gran = 1; - configfs_sb = sb; inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, - &configfs_root); + &configfs_root, sb); if (inode) { - inode->i_op = &configfs_dir_inode_operations; + inode->i_op = &configfs_root_inode_operations; inode->i_fop = &configfs_dir_operations; /* directory inodes start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); } else { - pr_debug("configfs: could not get root inode\n"); + pr_debug("could not get root inode\n"); return -ENOMEM; } - root = d_alloc_root(inode); + root = d_make_root(inode); if (!root) { pr_debug("%s: could not get root dentry!\n",__func__); - iput(inode); return -ENOMEM; } config_group_init(&configfs_root_group); configfs_root_group.cg_item.ci_dentry = root; root->d_fsdata = &configfs_root; sb->s_root = root; + sb->s_d_op = &configfs_dentry_ops; /* the rest get that */ return 0; } -static int configfs_get_sb(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data, struct vfsmount *mnt) +static struct dentry *configfs_do_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) { - return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt); + return mount_single(fs_type, flags, data, configfs_fill_super); } static struct file_system_type configfs_fs_type = { .owner = THIS_MODULE, .name = "configfs", - .get_sb = configfs_get_sb, + .mount = configfs_do_mount, .kill_sb = kill_litter_super, }; +MODULE_ALIAS_FS("configfs"); -int configfs_pin_fs(void) +struct dentry *configfs_pin_fs(void) { - return simple_pin_fs(&configfs_fs_type, &configfs_mount, + int err = simple_pin_fs(&configfs_fs_type, &configfs_mount, &configfs_mnt_count); + return err ? ERR_PTR(err) : configfs_mount->mnt_root; } void configfs_release_fs(void) @@ -141,28 +142,26 @@ static int __init configfs_init(void) goto out; config_kobj = kobject_create_and_add("config", kernel_kobj); - if (!config_kobj) { - kmem_cache_destroy(configfs_dir_cachep); - configfs_dir_cachep = NULL; - goto out; - } + if (!config_kobj) + goto out2; + + err = configfs_inode_init(); + if (err) + goto out3; err = register_filesystem(&configfs_fs_type); - if (err) { - printk(KERN_ERR "configfs: Unable to register filesystem!\n"); - kobject_put(config_kobj); - kmem_cache_destroy(configfs_dir_cachep); - configfs_dir_cachep = NULL; - goto out; - } + if (err) + goto out4; - err = configfs_inode_init(); - if (err) { - unregister_filesystem(&configfs_fs_type); - kobject_put(config_kobj); - kmem_cache_destroy(configfs_dir_cachep); - configfs_dir_cachep = NULL; - } + return 0; +out4: + pr_err("Unable to register filesystem!\n"); + configfs_inode_exit(); +out3: + kobject_put(config_kobj); +out2: + kmem_cache_destroy(configfs_dir_cachep); + configfs_dir_cachep = NULL; out: return err; } diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c index 932a92b3148..cc9f2546ea4 100644 --- a/fs/configfs/symlink.c +++ b/fs/configfs/symlink.c @@ -27,6 +27,7 @@ #include <linux/fs.h> #include <linux/module.h> #include <linux/namei.h> +#include <linux/slab.h> #include <linux/configfs.h> #include "configfs_internal.h" @@ -109,20 +110,22 @@ out: static int get_target(const char *symname, struct path *path, - struct config_item **target) + struct config_item **target, struct super_block *sb) { int ret; ret = kern_path(symname, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, path); if (!ret) { - if (path->dentry->d_sb == configfs_sb) { + if (path->dentry->d_sb == sb) { *target = configfs_get_config_item(path->dentry); if (!*target) { ret = -ENOENT; path_put(path); } - } else + } else { ret = -EPERM; + path_put(path); + } } return ret; @@ -135,13 +138,9 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna struct path path; struct configfs_dirent *sd; struct config_item *parent_item; - struct config_item *target_item; + struct config_item *target_item = NULL; struct config_item_type *type; - ret = -EPERM; /* What lack-of-symlink returns */ - if (dentry->d_parent == configfs_sb->s_root) - goto out; - sd = dentry->d_parent->d_fsdata; /* * Fake invisibility if dir belongs to a group/default groups hierarchy @@ -159,7 +158,7 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna !type->ct_item_ops->allow_link) goto out_put; - ret = get_target(symname, &path, &target_item); + ret = get_target(symname, &path, &target_item, dentry->d_sb); if (ret) goto out_put; @@ -195,8 +194,6 @@ int configfs_unlink(struct inode *dir, struct dentry *dentry) if (!(sd->s_type & CONFIGFS_ITEM_LINK)) goto out; - BUG_ON(dentry->d_parent == configfs_sb->s_root); - sl = sd->s_element; parent_item = configfs_get_config_item(dentry->d_parent); |