X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsysfs%2Fdir.c;h=aee966c44aacd1a0c7c89847cca9d0966595f62b;hb=5b37696fda07b8acf37beba3853f83106397ccdf;hp=40596a0eee526db8fac44d8667bcb83e638c9e34;hpb=8619f979898397582e366877fd5feeba7560d70c;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 40596a0..aee966c 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -14,14 +14,153 @@ #include #include "sysfs.h" -DECLARE_RWSEM(sysfs_rename_sem); -spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED; -spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; +DEFINE_MUTEX(sysfs_mutex); +spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; static DEFINE_IDA(sysfs_ino_ida); /** + * sysfs_link_sibling - link sysfs_dirent into sibling list + * @sd: sysfs_dirent of interest + * + * Link @sd into its sibling list which starts from + * sd->s_parent->s_children. + * + * Locking: + * mutex_lock(sysfs_mutex) + */ +void sysfs_link_sibling(struct sysfs_dirent *sd) +{ + struct sysfs_dirent *parent_sd = sd->s_parent; + + BUG_ON(sd->s_sibling); + sd->s_sibling = parent_sd->s_children; + parent_sd->s_children = sd; +} + +/** + * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list + * @sd: sysfs_dirent of interest + * + * Unlink @sd from its sibling list which starts from + * sd->s_parent->s_children. + * + * Locking: + * mutex_lock(sysfs_mutex) + */ +void sysfs_unlink_sibling(struct sysfs_dirent *sd) +{ + struct sysfs_dirent **pos; + + for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) { + if (*pos == sd) { + *pos = sd->s_sibling; + sd->s_sibling = NULL; + break; + } + } +} + +/** + * sysfs_get_dentry - get dentry for the given sysfs_dirent + * @sd: sysfs_dirent of interest + * + * Get dentry for @sd. Dentry is looked up if currently not + * present. This function climbs sysfs_dirent tree till it + * reaches a sysfs_dirent with valid dentry attached and descends + * down from there looking up dentry for each step. + * + * LOCKING: + * Kernel thread context (may sleep) + * + * RETURNS: + * Pointer to found dentry on success, ERR_PTR() value on error. + */ +struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd) +{ + struct sysfs_dirent *cur; + struct dentry *parent_dentry, *dentry; + int i, depth; + + /* Find the first parent which has valid s_dentry and get the + * dentry. + */ + mutex_lock(&sysfs_mutex); + restart0: + spin_lock(&sysfs_assoc_lock); + restart1: + spin_lock(&dcache_lock); + + dentry = NULL; + depth = 0; + cur = sd; + while (!cur->s_dentry || !cur->s_dentry->d_inode) { + if (cur->s_flags & SYSFS_FLAG_REMOVED) { + dentry = ERR_PTR(-ENOENT); + depth = 0; + break; + } + cur = cur->s_parent; + depth++; + } + if (!IS_ERR(dentry)) + dentry = dget_locked(cur->s_dentry); + + spin_unlock(&dcache_lock); + spin_unlock(&sysfs_assoc_lock); + + /* from the found dentry, look up depth times */ + while (depth--) { + /* find and get depth'th ancestor */ + for (cur = sd, i = 0; cur && i < depth; i++) + cur = cur->s_parent; + + /* This can happen if tree structure was modified due + * to move/rename. Restart. + */ + if (i != depth) { + dput(dentry); + goto restart0; + } + + sysfs_get(cur); + + mutex_unlock(&sysfs_mutex); + + /* look it up */ + parent_dentry = dentry; + dentry = lookup_one_len_kern(cur->s_name, parent_dentry, + strlen(cur->s_name)); + dput(parent_dentry); + + if (IS_ERR(dentry)) { + sysfs_put(cur); + return dentry; + } + + mutex_lock(&sysfs_mutex); + spin_lock(&sysfs_assoc_lock); + + /* This, again, can happen if tree structure has + * changed and we looked up the wrong thing. Restart. + */ + if (cur->s_dentry != dentry) { + dput(dentry); + sysfs_put(cur); + goto restart1; + } + + spin_unlock(&sysfs_assoc_lock); + + sysfs_put(cur); + } + + mutex_unlock(&sysfs_mutex); + return dentry; +} + +/** * sysfs_get_active - get an active reference to sysfs_dirent * @sd: sysfs_dirent to get an active reference to * @@ -73,9 +212,9 @@ void sysfs_put_active(struct sysfs_dirent *sd) return; /* atomic_dec_return() is a mb(), we'll always see the updated - * sd->s_sibling.next. + * sd->s_sibling. */ - cmpl = (void *)sd->s_sibling.next; + cmpl = (void *)sd->s_sibling; complete(cmpl); } @@ -124,23 +263,23 @@ void sysfs_put_active_two(struct sysfs_dirent *sd) * * Deny new active references and drain existing ones. */ -void sysfs_deactivate(struct sysfs_dirent *sd) +static void sysfs_deactivate(struct sysfs_dirent *sd) { DECLARE_COMPLETION_ONSTACK(wait); int v; - BUG_ON(!list_empty(&sd->s_sibling)); - sd->s_sibling.next = (void *)&wait; + BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); + sd->s_sibling = (void *)&wait; /* atomic_add_return() is a mb(), put_active() will always see - * the updated sd->s_sibling.next. + * the updated sd->s_sibling. */ v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); if (v != SD_DEACTIVATED_BIAS) wait_for_completion(&wait); - INIT_LIST_HEAD(&sd->s_sibling); + sd->s_sibling = NULL; } static int sysfs_alloc_ino(ino_t *pino) @@ -174,11 +313,14 @@ void release_sysfs_dirent(struct sysfs_dirent * sd) struct sysfs_dirent *parent_sd; repeat: + /* Moving/renaming is always done while holding reference. + * sd->s_parent won't change beneath us. + */ parent_sd = sd->s_parent; - if (sd->s_type & SYSFS_KOBJ_LINK) + if (sysfs_type(sd) == SYSFS_KOBJ_LINK) sysfs_put(sd->s_elem.symlink.target_sd); - if (sd->s_type & SYSFS_COPY_NAME) + if (sysfs_type(sd) & SYSFS_COPY_NAME) kfree(sd->s_name); kfree(sd->s_iattr); sysfs_free_ino(sd->s_ino); @@ -194,10 +336,10 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) struct sysfs_dirent * sd = dentry->d_fsdata; if (sd) { - /* sd->s_dentry is protected with sysfs_lock. This - * allows sysfs_drop_dentry() to dereference it. + /* sd->s_dentry is protected with sysfs_assoc_lock. + * This allows sysfs_drop_dentry() to dereference it. */ - spin_lock(&sysfs_lock); + spin_lock(&sysfs_assoc_lock); /* The dentry might have been deleted or another * lookup could have happened updating sd->s_dentry to @@ -206,7 +348,7 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) */ if (sd->s_dentry == dentry) sd->s_dentry = NULL; - spin_unlock(&sysfs_lock); + spin_unlock(&sysfs_assoc_lock); sysfs_put(sd); } iput(inode); @@ -237,12 +379,10 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) atomic_set(&sd->s_count, 1); atomic_set(&sd->s_active, 0); atomic_set(&sd->s_event, 1); - INIT_LIST_HEAD(&sd->s_children); - INIT_LIST_HEAD(&sd->s_sibling); sd->s_name = name; sd->s_mode = mode; - sd->s_type = type; + sd->s_flags = type; return sd; @@ -252,165 +392,381 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) return NULL; } +/** + * sysfs_attach_dentry - associate sysfs_dirent with dentry + * @sd: target sysfs_dirent + * @dentry: dentry to associate + * + * Associate @sd with @dentry. This is protected by + * sysfs_assoc_lock to avoid race with sysfs_d_iput(). + * + * LOCKING: + * mutex_lock(sysfs_mutex) + */ static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry) { dentry->d_op = &sysfs_dentry_ops; dentry->d_fsdata = sysfs_get(sd); /* protect sd->s_dentry against sysfs_d_iput */ - spin_lock(&sysfs_lock); + spin_lock(&sysfs_assoc_lock); sd->s_dentry = dentry; - spin_unlock(&sysfs_lock); + spin_unlock(&sysfs_assoc_lock); d_rehash(dentry); } -void sysfs_attach_dirent(struct sysfs_dirent *sd, - struct sysfs_dirent *parent_sd, struct dentry *dentry) +static int sysfs_ilookup_test(struct inode *inode, void *arg) { - if (dentry) - sysfs_attach_dentry(sd, dentry); - - if (parent_sd) { - sd->s_parent = sysfs_get(parent_sd); - list_add(&sd->s_sibling, &parent_sd->s_children); - } + struct sysfs_dirent *sd = arg; + return inode->i_ino == sd->s_ino; } -/* +/** + * sysfs_addrm_start - prepare for sysfs_dirent add/remove + * @acxt: pointer to sysfs_addrm_cxt to be used + * @parent_sd: parent sysfs_dirent * - * Return -EEXIST if there is already a sysfs element with the same name for - * the same parent. + * This function is called when the caller is about to add or + * remove sysfs_dirent under @parent_sd. This function acquires + * sysfs_mutex, grabs inode for @parent_sd if available and lock + * i_mutex of it. @acxt is used to keep and pass context to + * other addrm functions. * - * called with parent inode's i_mutex held + * LOCKING: + * Kernel thread context (may sleep). sysfs_mutex is locked on + * return. i_mutex of parent inode is locked on return if + * available. */ -int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, - const unsigned char *new) +void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, + struct sysfs_dirent *parent_sd) { - struct sysfs_dirent * sd; + struct inode *inode; - list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { - if (sd->s_type) { - if (strcmp(sd->s_name, new)) - continue; - else - return -EEXIST; + memset(acxt, 0, sizeof(*acxt)); + acxt->parent_sd = parent_sd; + + /* Lookup parent inode. inode initialization and I_NEW + * clearing are protected by sysfs_mutex. By grabbing it and + * looking up with _nowait variant, inode state can be + * determined reliably. + */ + mutex_lock(&sysfs_mutex); + + inode = ilookup5_nowait(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test, + parent_sd); + + if (inode && !(inode->i_state & I_NEW)) { + /* parent inode available */ + acxt->parent_inode = inode; + + /* sysfs_mutex is below i_mutex in lock hierarchy. + * First, trylock i_mutex. If fails, unlock + * sysfs_mutex and lock them in order. + */ + if (!mutex_trylock(&inode->i_mutex)) { + mutex_unlock(&sysfs_mutex); + mutex_lock(&inode->i_mutex); + mutex_lock(&sysfs_mutex); } - } + } else + iput(inode); +} - return 0; +/** + * sysfs_add_one - add sysfs_dirent to parent + * @acxt: addrm context to use + * @sd: sysfs_dirent to be added + * + * Get @acxt->parent_sd and set sd->s_parent to it and increment + * nlink of parent inode if @sd is a directory. @sd is NOT + * linked into the children list of the parent. The caller + * should invoke sysfs_link_sibling() after this function + * completes if @sd needs to be on the children list. + * + * This function should be called between calls to + * sysfs_addrm_start() and sysfs_addrm_finish() and should be + * passed the same @acxt as passed to sysfs_addrm_start(). + * + * LOCKING: + * Determined by sysfs_addrm_start(). + */ +void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) +{ + sd->s_parent = sysfs_get(acxt->parent_sd); + + if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) + inc_nlink(acxt->parent_inode); + + acxt->cnt++; } -static int create_dir(struct kobject *kobj, struct dentry *parent, - const char *name, struct dentry **p_dentry) +/** + * sysfs_remove_one - remove sysfs_dirent from parent + * @acxt: addrm context to use + * @sd: sysfs_dirent to be added + * + * Mark @sd removed and drop nlink of parent inode if @sd is a + * directory. @sd is NOT unlinked from the children list of the + * parent. The caller is repsonsible for removing @sd from the + * children list before calling this function. + * + * This function should be called between calls to + * sysfs_addrm_start() and sysfs_addrm_finish() and should be + * passed the same @acxt as passed to sysfs_addrm_start(). + * + * LOCKING: + * Determined by sysfs_addrm_start(). + */ +void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) { - int error; - umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; - struct dentry *dentry; + BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED)); + + sd->s_flags |= SYSFS_FLAG_REMOVED; + sd->s_sibling = acxt->removed; + acxt->removed = sd; + + if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) + drop_nlink(acxt->parent_inode); + + acxt->cnt++; +} + +/** + * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent + * @sd: target sysfs_dirent + * + * Drop dentry for @sd. @sd must have been unlinked from its + * parent on entry to this function such that it can't be looked + * up anymore. + * + * @sd->s_dentry which is protected with sysfs_assoc_lock points + * to the currently associated dentry but we're not holding a + * reference to it and racing with dput(). Grab dcache_lock and + * verify dentry before dropping it. If @sd->s_dentry is NULL or + * dput() beats us, no need to bother. + */ +static void sysfs_drop_dentry(struct sysfs_dirent *sd) +{ + struct dentry *dentry = NULL; struct inode *inode; - struct sysfs_dirent *sd; - mutex_lock(&parent->d_inode->i_mutex); + /* We're not holding a reference to ->s_dentry dentry but the + * field will stay valid as long as sysfs_assoc_lock is held. + */ + spin_lock(&sysfs_assoc_lock); + spin_lock(&dcache_lock); + + /* drop dentry if it's there and dput() didn't kill it yet */ + if (sd->s_dentry && sd->s_dentry->d_inode) { + dentry = dget_locked(sd->s_dentry); + spin_lock(&dentry->d_lock); + __d_drop(dentry); + spin_unlock(&dentry->d_lock); + } - /* allocate */ - dentry = lookup_one_len(name, parent, strlen(name)); - if (IS_ERR(dentry)) { - error = PTR_ERR(dentry); - goto out_unlock; + spin_unlock(&dcache_lock); + spin_unlock(&sysfs_assoc_lock); + + /* dentries for shadowed inodes are pinned, unpin */ + if (dentry && sysfs_is_shadowed_inode(dentry->d_inode)) + dput(dentry); + dput(dentry); + + /* adjust nlink and update timestamp */ + inode = ilookup(sysfs_sb, sd->s_ino); + if (inode) { + mutex_lock(&inode->i_mutex); + + inode->i_ctime = CURRENT_TIME; + drop_nlink(inode); + if (sysfs_type(sd) == SYSFS_DIR) + drop_nlink(inode); + + mutex_unlock(&inode->i_mutex); + iput(inode); } +} - error = -EEXIST; - if (dentry->d_inode) - goto out_dput; +/** + * sysfs_addrm_finish - finish up sysfs_dirent add/remove + * @acxt: addrm context to finish up + * + * Finish up sysfs_dirent add/remove. Resources acquired by + * sysfs_addrm_start() are released and removed sysfs_dirents are + * cleaned up. Timestamps on the parent inode are updated. + * + * LOCKING: + * All mutexes acquired by sysfs_addrm_start() are released. + * + * RETURNS: + * Number of added/removed sysfs_dirents since sysfs_addrm_start(). + */ +int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) +{ + /* release resources acquired by sysfs_addrm_start() */ + mutex_unlock(&sysfs_mutex); + if (acxt->parent_inode) { + struct inode *inode = acxt->parent_inode; - error = -ENOMEM; - sd = sysfs_new_dirent(name, mode, SYSFS_DIR); - if (!sd) - goto out_drop; - sd->s_elem.dir.kobj = kobj; + /* if added/removed, update timestamps on the parent */ + if (acxt->cnt) + inode->i_ctime = inode->i_mtime = CURRENT_TIME; - inode = sysfs_get_inode(sd); - if (!inode) - goto out_sput; + mutex_unlock(&inode->i_mutex); + iput(inode); + } - if (inode->i_state & I_NEW) { - inode->i_op = &sysfs_dir_inode_operations; - inode->i_fop = &sysfs_dir_operations; - /* directory inodes start off with i_nlink == 2 (for ".") */ - inc_nlink(inode); + /* kill removed sysfs_dirents */ + while (acxt->removed) { + struct sysfs_dirent *sd = acxt->removed; + + acxt->removed = sd->s_sibling; + sd->s_sibling = NULL; + + sysfs_drop_dentry(sd); + sysfs_deactivate(sd); + sysfs_put(sd); } - /* link in */ - error = -EEXIST; - if (sysfs_dirent_exist(parent->d_fsdata, name)) - goto out_iput; + return acxt->cnt; +} - sysfs_instantiate(dentry, inode); - inc_nlink(parent->d_inode); - sysfs_attach_dirent(sd, parent->d_fsdata, dentry); +/** + * sysfs_find_dirent - find sysfs_dirent with the given name + * @parent_sd: sysfs_dirent to search under + * @name: name to look for + * + * Look for sysfs_dirent with name @name under @parent_sd. + * + * LOCKING: + * mutex_lock(sysfs_mutex) + * + * RETURNS: + * Pointer to sysfs_dirent if found, NULL if not. + */ +struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name) +{ + struct sysfs_dirent *sd; - *p_dentry = dentry; - error = 0; - goto out_unlock; /* pin directory dentry in core */ + for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) + if (sysfs_type(sd) && !strcmp(sd->s_name, name)) + return sd; + return NULL; +} - out_iput: - iput(inode); - out_sput: - sysfs_put(sd); - out_drop: - d_drop(dentry); - out_dput: - dput(dentry); - out_unlock: - mutex_unlock(&parent->d_inode->i_mutex); - return error; +/** + * sysfs_get_dirent - find and get sysfs_dirent with the given name + * @parent_sd: sysfs_dirent to search under + * @name: name to look for + * + * Look for sysfs_dirent with name @name under @parent_sd and get + * it if found. + * + * LOCKING: + * Kernel thread context (may sleep). Grabs sysfs_mutex. + * + * RETURNS: + * Pointer to sysfs_dirent if found, NULL if not. + */ +struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name) +{ + struct sysfs_dirent *sd; + + mutex_lock(&sysfs_mutex); + sd = sysfs_find_dirent(parent_sd, name); + sysfs_get(sd); + mutex_unlock(&sysfs_mutex); + + return sd; } +static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, + const char *name, struct sysfs_dirent **p_sd) +{ + umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; + struct sysfs_addrm_cxt acxt; + struct sysfs_dirent *sd; -int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) + /* allocate */ + sd = sysfs_new_dirent(name, mode, SYSFS_DIR); + if (!sd) + return -ENOMEM; + sd->s_elem.dir.kobj = kobj; + + /* link in */ + sysfs_addrm_start(&acxt, parent_sd); + if (!sysfs_find_dirent(parent_sd, name)) { + sysfs_add_one(&acxt, sd); + sysfs_link_sibling(sd); + } + if (sysfs_addrm_finish(&acxt)) { + *p_sd = sd; + return 0; + } + + sysfs_put(sd); + return -EEXIST; +} + +int sysfs_create_subdir(struct kobject *kobj, const char *name, + struct sysfs_dirent **p_sd) { - return create_dir(k,k->dentry,n,d); + return create_dir(kobj, kobj->sd, name, p_sd); } /** * sysfs_create_dir - create a directory for an object. * @kobj: object we're creating directory for. - * @shadow_parent: parent parent object. + * @shadow_parent: parent object. */ - -int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent) +int sysfs_create_dir(struct kobject *kobj, + struct sysfs_dirent *shadow_parent_sd) { - struct dentry * dentry = NULL; - struct dentry * parent; + struct sysfs_dirent *parent_sd, *sd; int error = 0; BUG_ON(!kobj); - if (shadow_parent) - parent = shadow_parent; + if (shadow_parent_sd) + parent_sd = shadow_parent_sd; else if (kobj->parent) - parent = kobj->parent->dentry; + parent_sd = kobj->parent->sd; else if (sysfs_mount && sysfs_mount->mnt_sb) - parent = sysfs_mount->mnt_sb->s_root; + parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata; else return -EFAULT; - error = create_dir(kobj,parent,kobject_name(kobj),&dentry); + error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd); if (!error) - kobj->dentry = dentry; + kobj->sd = sd; return error; } +static int sysfs_count_nlink(struct sysfs_dirent *sd) +{ + struct sysfs_dirent *child; + int nr = 0; + + for (child = sd->s_children; child; child = child->s_sibling) + if (sysfs_type(child) == SYSFS_DIR) + nr++; + return nr + 2; +} + static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; struct sysfs_dirent * sd; + struct bin_attribute *bin_attr; struct inode *inode; int found = 0; - list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { - if ((sd->s_type & SYSFS_NOT_PINNED) && + for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) { + if (sysfs_type(sd) && !strcmp(sd->s_name, dentry->d_name.name)) { found = 1; break; @@ -426,23 +782,38 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, if (!inode) return ERR_PTR(-ENOMEM); + mutex_lock(&sysfs_mutex); + if (inode->i_state & I_NEW) { /* initialize inode according to type */ - if (sd->s_type & SYSFS_KOBJ_ATTR) { + switch (sysfs_type(sd)) { + case SYSFS_DIR: + inode->i_op = &sysfs_dir_inode_operations; + inode->i_fop = &sysfs_dir_operations; + inode->i_nlink = sysfs_count_nlink(sd); + break; + case SYSFS_KOBJ_ATTR: inode->i_size = PAGE_SIZE; inode->i_fop = &sysfs_file_operations; - } else if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) { - struct bin_attribute *bin_attr = - sd->s_elem.bin_attr.bin_attr; + break; + case SYSFS_KOBJ_BIN_ATTR: + bin_attr = sd->s_elem.bin_attr.bin_attr; inode->i_size = bin_attr->size; inode->i_fop = &bin_fops; - } else if (sd->s_type & SYSFS_KOBJ_LINK) + break; + case SYSFS_KOBJ_LINK: inode->i_op = &sysfs_symlink_inode_operations; + break; + default: + BUG(); + } } sysfs_instantiate(dentry, inode); sysfs_attach_dentry(sd, dentry); + mutex_unlock(&sysfs_mutex); + return NULL; } @@ -451,58 +822,46 @@ const struct inode_operations sysfs_dir_inode_operations = { .setattr = sysfs_setattr, }; -static void remove_dir(struct dentry * d) +static void remove_dir(struct sysfs_dirent *sd) { - struct dentry *parent = d->d_parent; - struct sysfs_dirent *sd = d->d_fsdata; - - mutex_lock(&parent->d_inode->i_mutex); - - list_del_init(&sd->s_sibling); - - pr_debug(" o %s removing done (%d)\n",d->d_name.name, - atomic_read(&d->d_count)); + struct sysfs_addrm_cxt acxt; - mutex_unlock(&parent->d_inode->i_mutex); - - sysfs_drop_dentry(sd); - sysfs_deactivate(sd); - sysfs_put(sd); + sysfs_addrm_start(&acxt, sd->s_parent); + sysfs_unlink_sibling(sd); + sysfs_remove_one(&acxt, sd); + sysfs_addrm_finish(&acxt); } -void sysfs_remove_subdir(struct dentry * d) +void sysfs_remove_subdir(struct sysfs_dirent *sd) { - remove_dir(d); + remove_dir(sd); } -static void __sysfs_remove_dir(struct dentry *dentry) +static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) { - LIST_HEAD(removed); - struct sysfs_dirent * parent_sd; - struct sysfs_dirent * sd, * tmp; + struct sysfs_addrm_cxt acxt; + struct sysfs_dirent **pos; - if (!dentry) + if (!dir_sd) return; - pr_debug("sysfs %s: removing dir\n",dentry->d_name.name); - mutex_lock(&dentry->d_inode->i_mutex); - parent_sd = dentry->d_fsdata; - list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { - if (!sd->s_type || !(sd->s_type & SYSFS_NOT_PINNED)) - continue; - list_move(&sd->s_sibling, &removed); - } - mutex_unlock(&dentry->d_inode->i_mutex); - - list_for_each_entry_safe(sd, tmp, &removed, s_sibling) { - list_del_init(&sd->s_sibling); - sysfs_drop_dentry(sd); - sysfs_deactivate(sd); - sysfs_put(sd); + pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); + sysfs_addrm_start(&acxt, dir_sd); + pos = &dir_sd->s_children; + while (*pos) { + struct sysfs_dirent *sd = *pos; + + if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) { + *pos = sd->s_sibling; + sd->s_sibling = NULL; + sysfs_remove_one(&acxt, sd); + } else + pos = &(*pos)->s_sibling; } + sysfs_addrm_finish(&acxt); - remove_dir(dentry); + remove_dir(dir_sd); } /** @@ -516,28 +875,38 @@ static void __sysfs_remove_dir(struct dentry *dentry) void sysfs_remove_dir(struct kobject * kobj) { - struct dentry *d = kobj->dentry; + struct sysfs_dirent *sd = kobj->sd; - spin_lock(&kobj_sysfs_assoc_lock); - kobj->dentry = NULL; - spin_unlock(&kobj_sysfs_assoc_lock); + spin_lock(&sysfs_assoc_lock); + kobj->sd = NULL; + spin_unlock(&sysfs_assoc_lock); - __sysfs_remove_dir(d); + __sysfs_remove_dir(sd); } -int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, +int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd, const char *new_name) { - struct sysfs_dirent *sd = kobj->dentry->d_fsdata; - struct sysfs_dirent *parent_sd = new_parent->d_fsdata; - struct dentry *new_dentry; - char *dup_name; + struct sysfs_dirent *sd = kobj->sd; + struct dentry *new_parent = NULL; + struct dentry *old_dentry = NULL, *new_dentry = NULL; + const char *dup_name = NULL; int error; - if (!new_parent) - return -EFAULT; + /* get dentries */ + old_dentry = sysfs_get_dentry(sd); + if (IS_ERR(old_dentry)) { + error = PTR_ERR(old_dentry); + goto out_dput; + } + + new_parent = sysfs_get_dentry(new_parent_sd); + if (IS_ERR(new_parent)) { + error = PTR_ERR(new_parent); + goto out_dput; + } - down_write(&sysfs_rename_sem); + /* lock new_parent and get dentry for new name */ mutex_lock(&new_parent->d_inode->i_mutex); new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); @@ -551,14 +920,14 @@ int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, * shadows of the same directory */ error = -EINVAL; - if (kobj->dentry->d_parent->d_inode != new_parent->d_inode || + if (old_dentry->d_parent->d_inode != new_parent->d_inode || new_dentry->d_parent->d_inode != new_parent->d_inode || - new_dentry == kobj->dentry) - goto out_dput; + old_dentry == new_dentry) + goto out_unlock; error = -EEXIST; if (new_dentry->d_inode) - goto out_dput; + goto out_unlock; /* rename kobject and sysfs_dirent */ error = -ENOMEM; @@ -568,81 +937,104 @@ int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, error = kobject_set_name(kobj, "%s", new_name); if (error) - goto out_free; + goto out_drop; - kfree(sd->s_name); + dup_name = sd->s_name; sd->s_name = new_name; /* move under the new parent */ d_add(new_dentry, NULL); - d_move(kobj->dentry, new_dentry); + d_move(sd->s_dentry, new_dentry); - list_del_init(&sd->s_sibling); - sysfs_get(parent_sd); + mutex_lock(&sysfs_mutex); + + sysfs_unlink_sibling(sd); + sysfs_get(new_parent_sd); sysfs_put(sd->s_parent); - sd->s_parent = parent_sd; - list_add(&sd->s_sibling, &parent_sd->s_children); + sd->s_parent = new_parent_sd; + sysfs_link_sibling(sd); + + mutex_unlock(&sysfs_mutex); error = 0; goto out_unlock; - out_free: - kfree(dup_name); out_drop: d_drop(new_dentry); - out_dput: - dput(new_dentry); out_unlock: mutex_unlock(&new_parent->d_inode->i_mutex); - up_write(&sysfs_rename_sem); + out_dput: + kfree(dup_name); + dput(new_parent); + dput(old_dentry); + dput(new_dentry); return error; } -int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent) +int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) { - struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry; - struct sysfs_dirent *new_parent_sd, *sd; + struct sysfs_dirent *sd = kobj->sd; + struct sysfs_dirent *new_parent_sd; + struct dentry *old_parent, *new_parent = NULL; + struct dentry *old_dentry = NULL, *new_dentry = NULL; int error; - old_parent_dentry = kobj->parent ? - kobj->parent->dentry : sysfs_mount->mnt_sb->s_root; - new_parent_dentry = new_parent ? - new_parent->dentry : sysfs_mount->mnt_sb->s_root; + BUG_ON(!sd->s_parent); + new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root; + + /* get dentries */ + old_dentry = sysfs_get_dentry(sd); + if (IS_ERR(old_dentry)) { + error = PTR_ERR(old_dentry); + goto out_dput; + } + old_parent = sd->s_parent->s_dentry; - if (old_parent_dentry->d_inode == new_parent_dentry->d_inode) - return 0; /* nothing to move */ + new_parent = sysfs_get_dentry(new_parent_sd); + if (IS_ERR(new_parent)) { + error = PTR_ERR(new_parent); + goto out_dput; + } + + if (old_parent->d_inode == new_parent->d_inode) { + error = 0; + goto out_dput; /* nothing to move */ + } again: - mutex_lock(&old_parent_dentry->d_inode->i_mutex); - if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) { - mutex_unlock(&old_parent_dentry->d_inode->i_mutex); + mutex_lock(&old_parent->d_inode->i_mutex); + if (!mutex_trylock(&new_parent->d_inode->i_mutex)) { + mutex_unlock(&old_parent->d_inode->i_mutex); goto again; } - new_parent_sd = new_parent_dentry->d_fsdata; - sd = kobj->dentry->d_fsdata; - - new_dentry = lookup_one_len(kobj->name, new_parent_dentry, - strlen(kobj->name)); + new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name)); if (IS_ERR(new_dentry)) { error = PTR_ERR(new_dentry); - goto out; + goto out_unlock; } else error = 0; d_add(new_dentry, NULL); - d_move(kobj->dentry, new_dentry); + d_move(sd->s_dentry, new_dentry); dput(new_dentry); /* Remove from old parent's list and insert into new parent's list. */ - list_del_init(&sd->s_sibling); + mutex_lock(&sysfs_mutex); + + sysfs_unlink_sibling(sd); sysfs_get(new_parent_sd); sysfs_put(sd->s_parent); sd->s_parent = new_parent_sd; - list_add(&sd->s_sibling, &new_parent_sd->s_children); + sysfs_link_sibling(sd); -out: - mutex_unlock(&new_parent_dentry->d_inode->i_mutex); - mutex_unlock(&old_parent_dentry->d_inode->i_mutex); + mutex_unlock(&sysfs_mutex); + out_unlock: + mutex_unlock(&new_parent->d_inode->i_mutex); + mutex_unlock(&old_parent->d_inode->i_mutex); + out_dput: + dput(new_parent); + dput(old_dentry); + dput(new_dentry); return error; } @@ -652,11 +1044,13 @@ static int sysfs_dir_open(struct inode *inode, struct file *file) struct sysfs_dirent * parent_sd = dentry->d_fsdata; struct sysfs_dirent * sd; - mutex_lock(&dentry->d_inode->i_mutex); sd = sysfs_new_dirent("_DIR_", 0, 0); - if (sd) - sysfs_attach_dirent(sd, parent_sd, NULL); - mutex_unlock(&dentry->d_inode->i_mutex); + if (sd) { + mutex_lock(&sysfs_mutex); + sd->s_parent = sysfs_get(parent_sd); + sysfs_link_sibling(sd); + mutex_unlock(&sysfs_mutex); + } file->private_data = sd; return sd ? 0 : -ENOMEM; @@ -664,12 +1058,11 @@ static int sysfs_dir_open(struct inode *inode, struct file *file) static int sysfs_dir_close(struct inode *inode, struct file *file) { - struct dentry * dentry = file->f_path.dentry; struct sysfs_dirent * cursor = file->private_data; - mutex_lock(&dentry->d_inode->i_mutex); - list_del_init(&cursor->s_sibling); - mutex_unlock(&dentry->d_inode->i_mutex); + mutex_lock(&sysfs_mutex); + sysfs_unlink_sibling(cursor); + mutex_unlock(&sysfs_mutex); release_sysfs_dirent(cursor); @@ -687,7 +1080,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) struct dentry *dentry = filp->f_path.dentry; struct sysfs_dirent * parent_sd = dentry->d_fsdata; struct sysfs_dirent *cursor = filp->private_data; - struct list_head *p, *q = &cursor->s_sibling; + struct sysfs_dirent **pos; ino_t ino; int i = filp->f_pos; @@ -710,17 +1103,24 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) i++; /* fallthrough */ default: + mutex_lock(&sysfs_mutex); + + pos = &parent_sd->s_children; + while (*pos != cursor) + pos = &(*pos)->s_sibling; + + /* unlink cursor */ + *pos = cursor->s_sibling; + if (filp->f_pos == 2) - list_move(q, &parent_sd->s_children); + pos = &parent_sd->s_children; - for (p=q->next; p!= &parent_sd->s_children; p=p->next) { - struct sysfs_dirent *next; + for ( ; *pos; pos = &(*pos)->s_sibling) { + struct sysfs_dirent *next = *pos; const char * name; int len; - next = list_entry(p, struct sysfs_dirent, - s_sibling); - if (!next->s_type) + if (!sysfs_type(next)) continue; name = next->s_name; @@ -729,12 +1129,16 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) if (filldir(dirent, name, len, filp->f_pos, ino, dt_type(next)) < 0) - return 0; + break; - list_move(q, p); - p = q; filp->f_pos++; } + + /* put cursor back in */ + cursor->s_sibling = *pos; + *pos = cursor; + + mutex_unlock(&sysfs_mutex); } return 0; } @@ -743,7 +1147,6 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) { struct dentry * dentry = file->f_path.dentry; - mutex_lock(&dentry->d_inode->i_mutex); switch (origin) { case 1: offset += file->f_pos; @@ -751,31 +1154,35 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) if (offset >= 0) break; default: - mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return -EINVAL; } if (offset != file->f_pos) { + mutex_lock(&sysfs_mutex); + file->f_pos = offset; if (file->f_pos >= 2) { struct sysfs_dirent *sd = dentry->d_fsdata; struct sysfs_dirent *cursor = file->private_data; - struct list_head *p; + struct sysfs_dirent **pos; loff_t n = file->f_pos - 2; - list_del(&cursor->s_sibling); - p = sd->s_children.next; - while (n && p != &sd->s_children) { - struct sysfs_dirent *next; - next = list_entry(p, struct sysfs_dirent, - s_sibling); - if (next->s_type) + sysfs_unlink_sibling(cursor); + + pos = &sd->s_children; + while (n && *pos) { + struct sysfs_dirent *next = *pos; + if (sysfs_type(next)) n--; - p = p->next; + pos = &(*pos)->s_sibling; } - list_add_tail(&cursor->s_sibling, p); + + cursor->s_sibling = *pos; + *pos = cursor; } + + mutex_unlock(&sysfs_mutex); } - mutex_unlock(&dentry->d_inode->i_mutex); + return offset; } @@ -788,12 +1195,20 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) int sysfs_make_shadowed_dir(struct kobject *kobj, void * (*follow_link)(struct dentry *, struct nameidata *)) { + struct dentry *dentry; struct inode *inode; struct inode_operations *i_op; - inode = kobj->dentry->d_inode; - if (inode->i_op != &sysfs_dir_inode_operations) + /* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */ + dentry = sysfs_get_dentry(kobj->sd); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + inode = dentry->d_inode; + if (inode->i_op != &sysfs_dir_inode_operations) { + dput(dentry); return -EINVAL; + } i_op = kmalloc(sizeof(*i_op), GFP_KERNEL); if (!i_op) @@ -818,18 +1233,25 @@ int sysfs_make_shadowed_dir(struct kobject *kobj, * directory. */ -struct dentry *sysfs_create_shadow_dir(struct kobject *kobj) +struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj) { - struct dentry *dir = kobj->dentry; - struct inode *inode = dir->d_inode; - struct dentry *parent = dir->d_parent; - struct sysfs_dirent *parent_sd = parent->d_fsdata; - struct dentry *shadow; + struct sysfs_dirent *parent_sd = kobj->sd->s_parent; + struct dentry *dir, *parent, *shadow; + struct inode *inode; struct sysfs_dirent *sd; + struct sysfs_addrm_cxt acxt; - shadow = ERR_PTR(-EINVAL); - if (!sysfs_is_shadowed_inode(inode)) + dir = sysfs_get_dentry(kobj->sd); + if (IS_ERR(dir)) { + sd = (void *)dir; goto out; + } + parent = dir->d_parent; + + inode = dir->d_inode; + sd = ERR_PTR(-EINVAL); + if (!sysfs_is_shadowed_inode(inode)) + goto out_dput; shadow = d_alloc(parent, &dir->d_name); if (!shadow) @@ -839,36 +1261,44 @@ struct dentry *sysfs_create_shadow_dir(struct kobject *kobj) if (!sd) goto nomem; sd->s_elem.dir.kobj = kobj; - /* point to parent_sd but don't attach to it */ - sd->s_parent = sysfs_get(parent_sd); - sysfs_attach_dirent(sd, NULL, shadow); + sysfs_addrm_start(&acxt, parent_sd); + + /* add but don't link into children list */ + sysfs_add_one(&acxt, sd); + + /* attach and instantiate dentry */ + sysfs_attach_dentry(sd, shadow); d_instantiate(shadow, igrab(inode)); - inc_nlink(inode); - inc_nlink(parent->d_inode); + inc_nlink(inode); /* tj: synchronization? */ + + sysfs_addrm_finish(&acxt); dget(shadow); /* Extra count - pin the dentry in core */ -out: - return shadow; -nomem: + goto out_dput; + + nomem: dput(shadow); - shadow = ERR_PTR(-ENOMEM); - goto out; + sd = ERR_PTR(-ENOMEM); + out_dput: + dput(dir); + out: + return sd; } /** * sysfs_remove_shadow_dir - remove an object's directory. - * @shadow: dentry of shadow directory + * @shadow_sd: sysfs_dirent of shadow directory * * 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 sysfs_rmdir() below, instead of calling separately. */ -void sysfs_remove_shadow_dir(struct dentry *shadow) +void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd) { - __sysfs_remove_dir(shadow); + __sysfs_remove_dir(shadow_sd); } const struct file_operations sysfs_dir_operations = {