diff options
Diffstat (limited to 'fs/configfs')
| -rw-r--r-- | fs/configfs/configfs_internal.h | 36 | ||||
| -rw-r--r-- | fs/configfs/dir.c | 306 | ||||
| -rw-r--r-- | fs/configfs/file.c | 280 | ||||
| -rw-r--r-- | fs/configfs/inode.c | 36 | ||||
| -rw-r--r-- | fs/configfs/mount.c | 9 | ||||
| -rw-r--r-- | fs/configfs/symlink.c | 197 |
6 files changed, 431 insertions, 433 deletions
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index f752d83a9c44..22dce2d35a4b 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -20,12 +20,21 @@ #include <linux/list.h> #include <linux/spinlock.h> +struct configfs_fragment { + atomic_t frag_count; + struct rw_semaphore frag_sem; + bool frag_dead; +}; + +void put_fragment(struct configfs_fragment *); +struct configfs_fragment *get_fragment(struct configfs_fragment *); + struct configfs_dirent { atomic_t s_count; int s_dependent_count; struct list_head s_sibling; struct list_head s_children; - struct list_head s_links; + int s_links; void * s_element; int s_type; umode_t s_mode; @@ -34,6 +43,7 @@ struct configfs_dirent { #ifdef CONFIG_LOCKDEP int s_depth; #endif + struct configfs_fragment *s_frag; }; #define CONFIGFS_ROOT 0x0001 @@ -56,13 +66,13 @@ extern struct kmem_cache *configfs_dir_cachep; extern int configfs_is_root(struct config_item *item); extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *); -extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *)); +extern struct inode *configfs_create(struct dentry *, umode_t mode); extern int configfs_create_file(struct config_item *, const struct configfs_attribute *); extern int configfs_create_bin_file(struct config_item *, const struct configfs_bin_attribute *); -extern int configfs_make_dirent(struct configfs_dirent *, - struct dentry *, void *, umode_t, int); +extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *, + void *, umode_t, int, struct configfs_fragment *); extern int configfs_dirent_is_ready(struct configfs_dirent *); extern void configfs_hash_and_remove(struct dentry * dir, const char * name); @@ -74,7 +84,6 @@ extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr); extern struct dentry *configfs_pin_fs(void); extern void configfs_release_fs(void); -extern struct rw_semaphore configfs_rename_sem; extern const struct file_operations configfs_dir_operations; extern const struct file_operations configfs_file_operations; extern const struct file_operations configfs_bin_file_operations; @@ -87,14 +96,8 @@ extern int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname); extern int configfs_unlink(struct inode *dir, struct dentry *dentry); -struct configfs_symlink { - struct list_head sl_list; - struct config_item *sl_target; -}; - -extern int configfs_create_link(struct configfs_symlink *sl, - struct dentry *parent, - struct dentry *dentry); +int configfs_create_link(struct configfs_dirent *target, struct dentry *parent, + struct dentry *dentry, char *body); static inline struct config_item * to_item(struct dentry * dentry) { @@ -122,11 +125,7 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry spin_lock(&dentry->d_lock); if (!d_unhashed(dentry)) { struct configfs_dirent * sd = dentry->d_fsdata; - if (sd->s_type & CONFIGFS_ITEM_LINK) { - struct configfs_symlink * sl = sd->s_element; - item = config_item_get(sl->sl_target); - } else - item = config_item_get(sd->s_element); + item = config_item_get(sd->s_element); } spin_unlock(&dentry->d_lock); @@ -137,6 +136,7 @@ static inline void release_configfs_dirent(struct configfs_dirent * sd) { if (!(sd->s_type & CONFIGFS_ROOT)) { kfree(sd->s_iattr); + put_fragment(sd->s_frag); kmem_cache_free(configfs_dir_cachep, sd); } } diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 92112915de8e..cf7b7e1d5bd7 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -22,7 +22,6 @@ #include <linux/configfs.h> #include "configfs_internal.h" -DECLARE_RWSEM(configfs_rename_sem); /* * Protects mutations of configfs_dirent linkage together with proper i_mutex * Also protects mutations of symlinks linkage to target configfs_dirent @@ -151,11 +150,38 @@ configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd) #endif /* CONFIG_LOCKDEP */ +static struct configfs_fragment *new_fragment(void) +{ + struct configfs_fragment *p; + + p = kmalloc(sizeof(struct configfs_fragment), GFP_KERNEL); + if (p) { + atomic_set(&p->frag_count, 1); + init_rwsem(&p->frag_sem); + p->frag_dead = false; + } + return p; +} + +void put_fragment(struct configfs_fragment *frag) +{ + if (frag && atomic_dec_and_test(&frag->frag_count)) + kfree(frag); +} + +struct configfs_fragment *get_fragment(struct configfs_fragment *frag) +{ + if (likely(frag)) + atomic_inc(&frag->frag_count); + return frag; +} + /* * 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, int type) + void *element, int type, + struct configfs_fragment *frag) { struct configfs_dirent * sd; @@ -164,7 +190,6 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren return ERR_PTR(-ENOMEM); atomic_set(&sd->s_count, 1); - INIT_LIST_HEAD(&sd->s_links); INIT_LIST_HEAD(&sd->s_children); sd->s_element = element; sd->s_type = type; @@ -175,6 +200,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren kmem_cache_free(configfs_dir_cachep, sd); return ERR_PTR(-ENOENT); } + sd->s_frag = get_fragment(frag); list_add(&sd->s_sibling, &parent_sd->s_children); spin_unlock(&configfs_dirent_lock); @@ -209,11 +235,11 @@ static int configfs_dirent_exists(struct configfs_dirent *parent_sd, int configfs_make_dirent(struct configfs_dirent * parent_sd, struct dentry * dentry, void * element, - umode_t mode, int type) + umode_t mode, int type, struct configfs_fragment *frag) { struct configfs_dirent * sd; - sd = configfs_new_dirent(parent_sd, element, type); + sd = configfs_new_dirent(parent_sd, element, type, frag); if (IS_ERR(sd)) return PTR_ERR(sd); @@ -225,30 +251,16 @@ int configfs_make_dirent(struct configfs_dirent * parent_sd, return 0; } -static void init_dir(struct inode * inode) +static void configfs_remove_dirent(struct dentry *dentry) { - inode->i_op = &configfs_dir_inode_operations; - inode->i_fop = &configfs_dir_operations; - - /* directory inodes start off with i_nlink == 2 (for "." entry) */ - inc_nlink(inode); -} - -static void configfs_init_file(struct inode * inode) -{ - inode->i_size = PAGE_SIZE; - inode->i_fop = &configfs_file_operations; -} - -static void configfs_init_bin_file(struct inode *inode) -{ - inode->i_size = 0; - inode->i_fop = &configfs_bin_file_operations; -} + struct configfs_dirent *sd = dentry->d_fsdata; -static void init_symlink(struct inode * inode) -{ - inode->i_op = &configfs_symlink_inode_operations; + if (!sd) + return; + spin_lock(&configfs_dirent_lock); + list_del_init(&sd->s_sibling); + spin_unlock(&configfs_dirent_lock); + configfs_put(sd); } /** @@ -260,11 +272,13 @@ static void init_symlink(struct inode * inode) * until it is validated by configfs_dir_set_ready() */ -static int configfs_create_dir(struct config_item *item, struct dentry *dentry) +static int configfs_create_dir(struct config_item *item, struct dentry *dentry, + struct configfs_fragment *frag) { int error; umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; struct dentry *p = dentry->d_parent; + struct inode *inode; BUG_ON(!item); @@ -273,25 +287,30 @@ static int configfs_create_dir(struct config_item *item, struct dentry *dentry) return error; error = configfs_make_dirent(p->d_fsdata, dentry, item, mode, - CONFIGFS_DIR | CONFIGFS_USET_CREATING); + CONFIGFS_DIR | CONFIGFS_USET_CREATING, + frag); if (unlikely(error)) return error; configfs_set_dir_dirent_depth(p->d_fsdata, dentry->d_fsdata); - error = configfs_create(dentry, mode, init_dir); - if (!error) { - inc_nlink(d_inode(p)); - item->ci_dentry = dentry; - } else { - struct configfs_dirent *sd = dentry->d_fsdata; - if (sd) { - spin_lock(&configfs_dirent_lock); - list_del_init(&sd->s_sibling); - spin_unlock(&configfs_dirent_lock); - configfs_put(sd); - } - } - return error; + inode = configfs_create(dentry, mode); + if (IS_ERR(inode)) + goto out_remove; + + inode->i_op = &configfs_dir_inode_operations; + inode->i_fop = &configfs_dir_operations; + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + d_instantiate(dentry, inode); + /* already hashed */ + dget(dentry); /* pin directory dentries in core */ + inc_nlink(d_inode(p)); + item->ci_dentry = dentry; + return 0; + +out_remove: + configfs_remove_dirent(dentry); + return PTR_ERR(inode); } /* @@ -332,40 +351,40 @@ int configfs_dirent_is_ready(struct configfs_dirent *sd) return ret; } -int configfs_create_link(struct configfs_symlink *sl, - struct dentry *parent, - struct dentry *dentry) +int configfs_create_link(struct configfs_dirent *target, struct dentry *parent, + struct dentry *dentry, char *body) { int err = 0; umode_t mode = S_IFLNK | S_IRWXUGO; + struct configfs_dirent *p = parent->d_fsdata; + struct inode *inode; - err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode, - CONFIGFS_ITEM_LINK); - if (!err) { - err = configfs_create(dentry, mode, init_symlink); - if (err) { - struct configfs_dirent *sd = dentry->d_fsdata; - if (sd) { - spin_lock(&configfs_dirent_lock); - list_del_init(&sd->s_sibling); - spin_unlock(&configfs_dirent_lock); - configfs_put(sd); - } - } - } - return err; + err = configfs_make_dirent(p, dentry, target, mode, CONFIGFS_ITEM_LINK, + p->s_frag); + if (err) + return err; + + inode = configfs_create(dentry, mode); + if (IS_ERR(inode)) + goto out_remove; + + inode->i_link = body; + inode->i_op = &configfs_symlink_inode_operations; + d_instantiate(dentry, inode); + dget(dentry); /* pin link dentries in core */ + return 0; + +out_remove: + configfs_remove_dirent(dentry); + return PTR_ERR(inode); } static void remove_dir(struct dentry * d) { struct dentry * parent = dget(d->d_parent); - struct configfs_dirent * sd; - sd = d->d_fsdata; - spin_lock(&configfs_dirent_lock); - list_del_init(&sd->s_sibling); - spin_unlock(&configfs_dirent_lock); - configfs_put(sd); + configfs_remove_dirent(d); + if (d_really_is_positive(d)) simple_rmdir(d_inode(parent),d); @@ -406,20 +425,27 @@ static void configfs_remove_dir(struct config_item * item) static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry) { struct configfs_attribute * attr = sd->s_element; - int error; + struct inode *inode; 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, - (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ? - configfs_init_bin_file : - configfs_init_file); - if (error) + inode = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG); + if (IS_ERR(inode)) { configfs_put(sd); - return error; + return PTR_ERR(inode); + } + if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) { + inode->i_size = 0; + inode->i_fop = &configfs_bin_file_operations; + } else { + inode->i_size = PAGE_SIZE; + inode->i_fop = &configfs_file_operations; + } + d_add(dentry, inode); + return 0; } static struct dentry * configfs_lookup(struct inode *dir, @@ -489,7 +515,7 @@ static int configfs_detach_prep(struct dentry *dentry, struct dentry **wait) parent_sd->s_type |= CONFIGFS_USET_DROPPING; ret = -EBUSY; - if (!list_empty(&parent_sd->s_links)) + if (parent_sd->s_links) goto out; ret = 0; @@ -599,7 +625,8 @@ static int populate_attrs(struct config_item *item) static int configfs_attach_group(struct config_item *parent_item, struct config_item *item, - struct dentry *dentry); + struct dentry *dentry, + struct configfs_fragment *frag); static void configfs_detach_group(struct config_item *item); static void detach_groups(struct config_group *group) @@ -647,7 +674,8 @@ static void detach_groups(struct config_group *group) * try using vfs_mkdir. Just a thought. */ static int create_default_group(struct config_group *parent_group, - struct config_group *group) + struct config_group *group, + struct configfs_fragment *frag) { int ret; struct configfs_dirent *sd; @@ -663,7 +691,7 @@ static int create_default_group(struct config_group *parent_group, d_add(child, NULL); ret = configfs_attach_group(&parent_group->cg_item, - &group->cg_item, child); + &group->cg_item, child, frag); if (!ret) { sd = child->d_fsdata; sd->s_type |= CONFIGFS_USET_DEFAULT; @@ -677,13 +705,14 @@ static int create_default_group(struct config_group *parent_group, return ret; } -static int populate_groups(struct config_group *group) +static int populate_groups(struct config_group *group, + struct configfs_fragment *frag) { struct config_group *new_group; int ret = 0; list_for_each_entry(new_group, &group->default_groups, group_entry) { - ret = create_default_group(group, new_group); + ret = create_default_group(group, new_group, frag); if (ret) { detach_groups(group); break; @@ -797,11 +826,12 @@ static void link_group(struct config_group *parent_group, struct config_group *g */ static int configfs_attach_item(struct config_item *parent_item, struct config_item *item, - struct dentry *dentry) + struct dentry *dentry, + struct configfs_fragment *frag) { int ret; - ret = configfs_create_dir(item, dentry); + ret = configfs_create_dir(item, dentry, frag); if (!ret) { ret = populate_attrs(item); if (ret) { @@ -831,12 +861,13 @@ static void configfs_detach_item(struct config_item *item) static int configfs_attach_group(struct config_item *parent_item, struct config_item *item, - struct dentry *dentry) + struct dentry *dentry, + struct configfs_fragment *frag) { int ret; struct configfs_dirent *sd; - ret = configfs_attach_item(parent_item, item, dentry); + ret = configfs_attach_item(parent_item, item, dentry, frag); if (!ret) { sd = dentry->d_fsdata; sd->s_type |= CONFIGFS_USET_DIR; @@ -852,7 +883,7 @@ static int configfs_attach_group(struct config_item *parent_item, */ inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD); configfs_adjust_dir_dirent_depth_before_populate(sd); - ret = populate_groups(to_config_group(item)); + ret = populate_groups(to_config_group(item), frag); if (ret) { configfs_detach_item(item); d_inode(dentry)->i_flags |= S_DEAD; @@ -1247,6 +1278,7 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode struct configfs_dirent *sd; const struct config_item_type *type; struct module *subsys_owner = NULL, *new_item_owner = NULL; + struct configfs_fragment *frag; char *name; sd = dentry->d_parent->d_fsdata; @@ -1265,6 +1297,12 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode goto out; } + frag = new_fragment(); + if (!frag) { + ret = -ENOMEM; + goto out; + } + /* Get a working ref for the duration of this function */ parent_item = configfs_get_config_item(dentry->d_parent); type = parent_item->ci_type; @@ -1367,9 +1405,9 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode spin_unlock(&configfs_dirent_lock); if (group) - ret = configfs_attach_group(parent_item, item, dentry); + ret = configfs_attach_group(parent_item, item, dentry, frag); else - ret = configfs_attach_item(parent_item, item, dentry); + ret = configfs_attach_item(parent_item, item, dentry, frag); spin_lock(&configfs_dirent_lock); sd->s_type &= ~CONFIGFS_USET_IN_MKDIR; @@ -1406,6 +1444,7 @@ out_put: * reference. */ config_item_put(parent_item); + put_fragment(frag); out: return ret; @@ -1417,6 +1456,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) struct config_item *item; struct configfs_subsystem *subsys; struct configfs_dirent *sd; + struct configfs_fragment *frag; struct module *subsys_owner = NULL, *dead_item_owner = NULL; int ret; @@ -1474,6 +1514,16 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry) } } while (ret == -EAGAIN); + frag = sd->s_frag; + if (down_write_killable(&frag->frag_sem)) { + spin_lock(&configfs_dirent_lock); + configfs_detach_rollback(dentry); + spin_unlock(&configfs_dirent_lock); + return -EINTR; + } + frag->frag_dead = true; + up_write(&frag->frag_sem); + /* Get a working ref for the duration of this function */ item = configfs_get_config_item(dentry); @@ -1523,44 +1573,6 @@ const struct inode_operations configfs_root_inode_operations = { .setattr = configfs_setattr, }; -#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; - - inode_lock(d_inode(parent)); - - new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); - if (!IS_ERR(new_dentry)) { - if (d_really_is_negative(new_dentry)) { - 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); - } - inode_unlock(d_inode(parent)); - up_write(&configfs_rename_sem); - - return error; -} -#endif - static int configfs_dir_open(struct inode *inode, struct file *file) { struct dentry * dentry = file->f_path.dentry; @@ -1574,7 +1586,7 @@ 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, 0); + file->private_data = configfs_new_dirent(parent_sd, NULL, 0, NULL); if (IS_ERR(file->private_data)) err = PTR_ERR(file->private_data); else @@ -1732,8 +1744,13 @@ int configfs_register_group(struct config_group *parent_group, { struct configfs_subsystem *subsys = parent_group->cg_subsys; struct dentry *parent; + struct configfs_fragment *frag; int ret; + frag = new_fragment(); + if (!frag) + return -ENOMEM; + mutex_lock(&subsys->su_mutex); link_group(parent_group, group); mutex_unlock(&subsys->su_mutex); @@ -1741,7 +1758,7 @@ int configfs_register_group(struct config_group *parent_group, parent = parent_group->cg_item.ci_dentry; inode_lock_nested(d_inode(parent), I_MUTEX_PARENT); - ret = create_default_group(parent_group, group); + ret = create_default_group(parent_group, group, frag); if (ret) goto err_out; @@ -1749,12 +1766,14 @@ int configfs_register_group(struct config_group *parent_group, configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata); spin_unlock(&configfs_dirent_lock); inode_unlock(d_inode(parent)); + put_fragment(frag); return 0; err_out: inode_unlock(d_inode(parent)); mutex_lock(&subsys->su_mutex); unlink_group(group); mutex_unlock(&subsys->su_mutex); + put_fragment(frag); return ret; } EXPORT_SYMBOL(configfs_register_group); @@ -1770,16 +1789,12 @@ void configfs_unregister_group(struct config_group *group) struct configfs_subsystem *subsys = group->cg_subsys; struct dentry *dentry = group->cg_item.ci_dentry; struct dentry *parent = group->cg_item.ci_parent->ci_dentry; + struct configfs_dirent *sd = dentry->d_fsdata; + struct configfs_fragment *frag = sd->s_frag; - mutex_lock(&subsys->su_mutex); - if (!group->cg_item.ci_parent->ci_group) { - /* - * The parent has already been unlinked and detached - * due to a rmdir. - */ - goto unlink_group; - } - mutex_unlock(&subsys->su_mutex); + down_write(&frag->frag_sem); + frag->frag_dead = true; + up_write(&frag->frag_sem); inode_lock_nested(d_inode(parent), I_MUTEX_PARENT); spin_lock(&configfs_dirent_lock); @@ -1796,7 +1811,6 @@ void configfs_unregister_group(struct config_group *group) dput(dentry); mutex_lock(&subsys->su_mutex); -unlink_group: unlink_group(group); mutex_unlock(&subsys->su_mutex); } @@ -1853,10 +1867,17 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) struct dentry *dentry; struct dentry *root; struct configfs_dirent *sd; + struct configfs_fragment *frag; + + frag = new_fragment(); + if (!frag) + return -ENOMEM; root = configfs_pin_fs(); - if (IS_ERR(root)) + if (IS_ERR(root)) { + put_fragment(frag); return PTR_ERR(root); + } if (!group->cg_item.ci_name) group->cg_item.ci_name = group->cg_item.ci_namebuf; @@ -1872,7 +1893,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) d_add(dentry, NULL); err = configfs_attach_group(sd->s_element, &group->cg_item, - dentry); + dentry, frag); if (err) { BUG_ON(d_inode(dentry)); d_drop(dentry); @@ -1890,6 +1911,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) unlink_group(group); configfs_release_fs(); } + put_fragment(frag); return err; } @@ -1899,12 +1921,18 @@ 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; + struct configfs_dirent *sd = dentry->d_fsdata; + struct configfs_fragment *frag = sd->s_frag; if (dentry->d_parent != root) { pr_err("Tried to unregister non-subsystem!\n"); return; } + down_write(&frag->frag_sem); + frag->frag_dead = true; + up_write(&frag->frag_sem); + inode_lock_nested(d_inode(root), I_MUTEX_PARENT); inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD); diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 61e4db4390a1..fb65b706cc0d 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -39,40 +39,44 @@ struct configfs_buffer { bool write_in_progress; char *bin_buffer; int bin_buffer_size; + int cb_max_size; + struct config_item *item; + struct module *owner; + union { + struct configfs_attribute *attr; + struct configfs_bin_attribute *bin_attr; + }; }; +static inline struct configfs_fragment *to_frag(struct file *file) +{ + struct configfs_dirent *sd = file->f_path.dentry->d_fsdata; -/** - * fill_read_buffer - allocate and fill buffer from item. - * @dentry: dentry pointer. - * @buffer: data buffer for file. - * - * Allocate @buffer->page, if it hasn't been already, then call the - * config_item's show() method to fill the buffer with this attribute's - * data. - * This is called only once, on the file's first read. - */ -static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buffer) + return sd->s_frag; +} + +static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer) { - struct configfs_attribute * attr = to_attr(dentry); - struct config_item * item = to_item(dentry->d_parent); - int ret = 0; - ssize_t count; + struct configfs_fragment *frag = to_frag(file); + ssize_t count = -ENOENT; if (!buffer->page) buffer->page = (char *) get_zeroed_page(GFP_KERNEL); if (!buffer->page) return -ENOMEM; - count = attr->show(item, buffer->page); - - BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE); - if (count >= 0) { - buffer->needs_read_fill = 0; - buffer->count = count; - } else - ret = count; - return ret; + down_read(&frag->frag_sem); + if (!frag->frag_dead) + count = buffer->attr->show(buffer->item, buffer->page); + up_read(&frag->frag_sem); + + if (count < 0) + return count; + if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE)) + return -EIO; + buffer->needs_read_fill = 0; + buffer->count = count; + return 0; } /** @@ -97,12 +101,13 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf static ssize_t configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - struct configfs_buffer * buffer = file->private_data; + struct configfs_buffer *buffer = file->private_data; ssize_t retval = 0; mutex_lock(&buffer->mutex); if (buffer->needs_read_fill) { - if ((retval = fill_read_buffer(file->f_path.dentry,buffer))) + retval = fill_read_buffer(file, buffer); + if (retval) goto out; } pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", @@ -138,10 +143,8 @@ static ssize_t configfs_read_bin_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) { + struct configfs_fragment *frag = to_frag(file); struct configfs_buffer *buffer = file->private_data; - struct dentry *dentry = file->f_path.dentry; - struct config_item *item = to_item(dentry->d_parent); - struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); ssize_t retval = 0; ssize_t len = min_t(size_t, count, PAGE_SIZE); @@ -156,14 +159,19 @@ configfs_read_bin_file(struct file *file, char __user *buf, if (buffer->needs_read_fill) { /* perform first read with buf == NULL to get extent */ - len = bin_attr->read(item, NULL, 0); + down_read(&frag->frag_sem); + if (!frag->frag_dead) + len = buffer->bin_attr->read(buffer->item, NULL, 0); + else + len = -ENOENT; + up_read(&frag->frag_sem); if (len <= 0) { retval = len; goto out; } /* do not exceed the maximum value */ - if (bin_attr->cb_max_size && len > bin_attr->cb_max_size) { + if (buffer->cb_max_size && len > buffer->cb_max_size) { retval = -EFBIG; goto out; } @@ -176,7 +184,13 @@ configfs_read_bin_file(struct file *file, char __user *buf, buffer->bin_buffer_size = len; /* perform second read to fill buffer */ - len = bin_attr->read(item, buffer->bin_buffer, len); + down_read(&frag->frag_sem); + if (!frag->frag_dead) + len = buffer->bin_attr->read(buffer->item, + buffer->bin_buffer, len); + else + len = -ENOENT; + up_read(&frag->frag_sem); if (len < 0) { retval = len; vfree(buffer->bin_buffer); @@ -226,25 +240,17 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size return error ? -EFAULT : count; } - -/** - * flush_write_buffer - push buffer to config_item. - * @dentry: dentry to the attribute - * @buffer: data buffer for file. - * @count: number of bytes - * - * Get the correct pointers for the config_item and the attribute we're - * dealing with, then call the store() method for the attribute, - * passing the buffer that we acquired in fill_write_buffer(). - */ - static int -flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size_t count) +flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count) { - struct configfs_attribute * attr = to_attr(dentry); - struct config_item * item = to_item(dentry->d_parent); - - return attr->store(item, buffer->page, count); + struct configfs_fragment *frag = to_frag(file); + int res = -ENOENT; + + down_read(&frag->frag_sem); + if (!frag->frag_dead) + res = buffer->attr->store(buffer->item, buffer->page, count); + up_read(&frag->frag_sem); + return res; } @@ -268,13 +274,13 @@ flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size static ssize_t configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - struct configfs_buffer * buffer = file->private_data; + struct configfs_buffer *buffer = file->private_data; ssize_t len; mutex_lock(&buffer->mutex); len = fill_write_buffer(buffer, buf, count); if (len > 0) - len = flush_write_buffer(file->f_path.dentry, buffer, len); + len = flush_write_buffer(file, buffer, len); if (len > 0) *ppos += len; mutex_unlock(&buffer->mutex); @@ -299,8 +305,6 @@ configfs_write_bin_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct configfs_buffer *buffer = file->private_data; - struct dentry *dentry = file->f_path.dentry; - struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); void *tbuf = NULL; ssize_t len; @@ -316,8 +320,8 @@ configfs_write_bin_file(struct file *file, const char __user *buf, /* buffer grows? */ if (*ppos + count > buffer->bin_buffer_size) { - if (bin_attr->cb_max_size && - *ppos + count > bin_attr->cb_max_size) { + if (buffer->cb_max_size && + *ppos + count > buffer->cb_max_size) { len = -EFBIG; goto out; } @@ -349,31 +353,51 @@ out: return len; } -static int check_perm(struct inode * inode, struct file * file, int type) +static int __configfs_open_file(struct inode *inode, struct file *file, int type) { - struct config_item *item = configfs_get_config_item(file->f_path.dentry->d_parent); - struct configfs_attribute * attr = to_attr(file->f_path.dentry); - struct configfs_bin_attribute *bin_attr = NULL; - struct configfs_buffer * buffer; - struct configfs_item_operations * ops = NULL; - int error = 0; + struct dentry *dentry = file->f_path.dentry; + struct configfs_fragment *frag = to_frag(file); + struct configfs_attribute *attr; + struct configfs_buffer *buffer; + int error; - if (!item || !attr) - goto Einval; + error = -ENOMEM; + buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL); + if (!buffer) + goto out; - if (type & CONFIGFS_ITEM_BIN_ATTR) - bin_attr = to_bin_attr(file->f_path.dentry); + error = -ENOENT; + down_read(&frag->frag_sem); + if (unlikely(frag->frag_dead)) + goto out_free_buffer; - /* Grab the module reference for this attribute if we have one */ - if (!try_module_get(attr->ca_owner)) { - error = -ENODEV; - goto Done; + error = -EINVAL; + buffer->item = to_item(dentry->d_parent); + if (!buffer->item) + goto out_free_buffer; + + attr = to_attr(dentry); + if (!attr) + goto out_put_item; + + if (type & CONFIGFS_ITEM_BIN_ATTR) { + buffer->bin_attr = to_bin_attr(dentry); + buffer->cb_max_size = buffer->bin_attr->cb_max_size; + } else { + buffer->attr = attr; } - if (item->ci_type) - ops = item->ci_type->ct_item_ops; - else - goto Eaccess; + buffer->owner = attr->ca_owner; + /* Grab the module reference for this attribute if we have one */ + error = -ENODEV; + if (!try_module_get(buffer->owner)) + goto out_put_item; + + error = -EACCES; + if (!buffer->item->ci_type) + goto out_put_module; + + buffer->ops = buffer->item->ci_type->ct_item_ops; /* File needs write support. * The inode's perms must say it's ok, @@ -381,13 +405,11 @@ static int check_perm(struct inode * inode, struct file * file, int type) */ if (file->f_mode & FMODE_WRITE) { if (!(inode->i_mode & S_IWUGO)) - goto Eaccess; - + goto out_put_module; if ((type & CONFIGFS_ITEM_ATTR) && !attr->store) - goto Eaccess; - - if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->write) - goto Eaccess; + goto out_put_module; + if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write) + goto out_put_module; } /* File needs read support. @@ -396,92 +418,72 @@ static int check_perm(struct inode * inode, struct file * file, int type) */ if (file->f_mode & FMODE_READ) { if (!(inode->i_mode & S_IRUGO)) - goto Eaccess; - + goto out_put_module; if ((type & CONFIGFS_ITEM_ATTR) && !attr->show) - goto Eaccess; - - if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->read) - goto Eaccess; + goto out_put_module; + if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read) + goto out_put_module; } - /* No error? Great, allocate a buffer for the file, and store it - * it in file->private_data for easy access. - */ - buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL); - if (!buffer) { - error = -ENOMEM; - goto Enomem; - } mutex_init(&buffer->mutex); buffer->needs_read_fill = 1; buffer->read_in_progress = false; buffer->write_in_progress = false; - buffer->ops = ops; file->private_data = buffer; - goto Done; + up_read(&frag->frag_sem); + return 0; - Einval: - error = -EINVAL; - goto Done; - Eaccess: - error = -EACCES; - Enomem: - module_put(attr->ca_owner); - Done: - if (error && item) - config_item_put(item); +out_put_module: + module_put(buffer->owner); +out_put_item: + config_item_put(buffer->item); +out_free_buffer: + up_read(&frag->frag_sem); + kfree(buffer); +out: return error; } static int configfs_release(struct inode *inode, struct file *filp) { - struct config_item * item = to_item(filp->f_path.dentry->d_parent); - struct configfs_attribute * attr = to_attr(filp->f_path.dentry); - struct module * owner = attr->ca_owner; - struct configfs_buffer * buffer = filp->private_data; - - if (item) - config_item_put(item); - /* After this point, attr should not be accessed. */ - module_put(owner); - - if (buffer) { - if (buffer->page) - free_page((unsigned long)buffer->page); - mutex_destroy(&buffer->mutex); - kfree(buffer); - } + struct configfs_buffer *buffer = filp->private_data; + + module_put(buffer->owner); + if (buffer->page) + free_page((unsigned long)buffer->page); + mutex_destroy(&buffer->mutex); + kfree(buffer); return 0; } static int configfs_open_file(struct inode *inode, struct file *filp) { - return check_perm(inode, filp, CONFIGFS_ITEM_ATTR); + return __configfs_open_file(inode, filp, CONFIGFS_ITEM_ATTR); } static int configfs_open_bin_file(struct inode *inode, struct file *filp) { - return check_perm(inode, filp, CONFIGFS_ITEM_BIN_ATTR); + return __configfs_open_file(inode, filp, CONFIGFS_ITEM_BIN_ATTR); } -static int configfs_release_bin_file(struct inode *inode, struct file *filp) +static int configfs_release_bin_file(struct inode *inode, struct file *file) { - struct configfs_buffer *buffer = filp->private_data; - struct dentry *dentry = filp->f_path.dentry; - struct config_item *item = to_item(dentry->d_parent); - struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); - ssize_t len = 0; - int ret; + struct configfs_buffer *buffer = file->private_data; buffer->read_in_progress = false; if (buffer->write_in_progress) { + struct configfs_fragment *frag = to_frag(file); buffer->write_in_progress = false; - len = bin_attr->write(item, buffer->bin_buffer, - buffer->bin_buffer_size); - + down_read(&frag->frag_sem); + if (!frag->frag_dead) { + /* result of ->release() is ignored */ + buffer->bin_attr->write(buffer->item, + buffer->bin_buffer, + buffer->bin_buffer_size); + } + up_read(&frag->frag_sem); /* vfree on NULL is safe */ vfree(buffer->bin_buffer); buffer->bin_buffer = NULL; @@ -489,10 +491,8 @@ static int configfs_release_bin_file(struct inode *inode, struct file *filp) buffer->needs_read_fill = 1; } - ret = configfs_release(inode, filp); - if (len < 0) - return len; - return ret; + configfs_release(inode, file); + return 0; } @@ -527,7 +527,7 @@ int configfs_create_file(struct config_item * item, const struct configfs_attrib inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL); error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, - CONFIGFS_ITEM_ATTR); + CONFIGFS_ITEM_ATTR, parent_sd->s_frag); inode_unlock(d_inode(dir)); return error; @@ -549,7 +549,7 @@ int configfs_create_bin_file(struct config_item *item, inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL); error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode, - CONFIGFS_ITEM_BIN_ATTR); + CONFIGFS_ITEM_BIN_ATTR, parent_sd->s_frag); inode_unlock(dir->d_inode); return error; diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index ab0284321912..680aba9c00d5 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -76,14 +76,14 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr) if (ia_valid & ATTR_GID) sd_iattr->ia_gid = iattr->ia_gid; if (ia_valid & ATTR_ATIME) - sd_iattr->ia_atime = timespec64_trunc(iattr->ia_atime, - inode->i_sb->s_time_gran); + sd_iattr->ia_atime = timestamp_truncate(iattr->ia_atime, + inode); if (ia_valid & ATTR_MTIME) - sd_iattr->ia_mtime = timespec64_trunc(iattr->ia_mtime, - inode->i_sb->s_time_gran); + sd_iattr->ia_mtime = timestamp_truncate(iattr->ia_mtime, + inode); if (ia_valid & ATTR_CTIME) - sd_iattr->ia_ctime = timespec64_trunc(iattr->ia_ctime, - inode->i_sb->s_time_gran); + sd_iattr->ia_ctime = timestamp_truncate(iattr->ia_ctime, + inode); if (ia_valid & ATTR_MODE) { umode_t mode = iattr->ia_mode; @@ -164,41 +164,27 @@ static void configfs_set_inode_lock_class(struct configfs_dirent *sd, #endif /* CONFIG_LOCKDEP */ -int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct inode *)) +struct inode *configfs_create(struct dentry *dentry, umode_t mode) { - int error = 0; struct inode *inode = NULL; struct configfs_dirent *sd; struct inode *p_inode; if (!dentry) - return -ENOENT; + return ERR_PTR(-ENOENT); if (d_really_is_positive(dentry)) - return -EEXIST; + return ERR_PTR(-EEXIST); sd = dentry->d_fsdata; inode = configfs_new_inode(mode, sd, dentry->d_sb); if (!inode) - return -ENOMEM; + return ERR_PTR(-ENOMEM); p_inode = d_inode(dentry->d_parent); p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode); configfs_set_inode_lock_class(sd, inode); - - init(inode); - if (S_ISDIR(mode) || S_ISLNK(mode)) { - /* - * ->symlink(), ->mkdir(), configfs_register_subsystem() or - * create_default_group() - already hashed. - */ - d_instantiate(dentry, inode); - dget(dentry); /* pin link and directory dentries in core */ - } else { - /* ->lookup() */ - d_add(dentry, inode); - } - return error; + return inode; } /* diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c index 55438dd58189..0c6e8cf61953 100644 --- a/fs/configfs/mount.c +++ b/fs/configfs/mount.c @@ -28,9 +28,18 @@ static struct vfsmount *configfs_mount = NULL; struct kmem_cache *configfs_dir_cachep; static int configfs_mnt_count = 0; + +static void configfs_free_inode(struct inode *inode) +{ + if (S_ISLNK(inode->i_mode)) + kfree(inode->i_link); + free_inode_nonrcu(inode); +} + static const struct super_operations configfs_ops = { .statfs = simple_statfs, .drop_inode = generic_delete_inode, + .free_inode = configfs_free_inode, }; static struct config_group configfs_root_group = { diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c index 91eac6c55e07..dc5dbf6a81d7 100644 --- a/fs/configfs/symlink.c +++ b/fs/configfs/symlink.c @@ -55,41 +55,63 @@ static void fill_item_path(struct config_item * item, char * buffer, int length) } } +static int configfs_get_target_path(struct config_item *item, + struct config_item *target, char *path) +{ + int depth, size; + char *s; + + depth = item_depth(item); + size = item_path_length(target) + depth * 3 - 1; + if (size > PATH_MAX) + return -ENAMETOOLONG; + + pr_debug("%s: depth = %d, size = %d\n", __func__, depth, size); + + for (s = path; depth--; s += 3) + strcpy(s,"../"); + + fill_item_path(target, path, size); + pr_debug("%s: path = '%s'\n", __func__, path); + return 0; +} + static int create_link(struct config_item *parent_item, struct config_item *item, struct dentry *dentry) { struct configfs_dirent *target_sd = item->ci_dentry->d_fsdata; - struct configfs_symlink *sl; + char *body; int ret; - ret = -ENOENT; if (!configfs_dirent_is_ready(target_sd)) - goto out; - ret = -ENOMEM; - sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL); - if (sl) { + return -ENOENT; + + body = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!body) + return -ENOMEM; + + configfs_get(target_sd); + spin_lock(&configfs_dirent_lock); + if (target_sd->s_type & CONFIGFS_USET_DROPPING) { + spin_unlock(&configfs_dirent_lock); + configfs_put(target_sd); + kfree(body); + return -ENOENT; + } + target_sd->s_links++; + spin_unlock(&configfs_dirent_lock); + ret = configfs_get_target_path(item, item, body); + if (!ret) + ret = configfs_create_link(target_sd, parent_item->ci_dentry, + dentry, body); + if (ret) { spin_lock(&configfs_dirent_lock); - if (target_sd->s_type & CONFIGFS_USET_DROPPING) { - spin_unlock(&configfs_dirent_lock); - kfree(sl); - return -ENOENT; - } - sl->sl_target = config_item_get(item); - list_add(&sl->sl_list, &target_sd->s_links); + target_sd->s_links--; spin_unlock(&configfs_dirent_lock); - ret = configfs_create_link(sl, parent_item->ci_dentry, - dentry); - if (ret) { - spin_lock(&configfs_dirent_lock); - list_del_init(&sl->sl_list); - spin_unlock(&configfs_dirent_lock); - config_item_put(item); - kfree(sl); - } + configfs_put(target_sd); + kfree(body); } - -out: return ret; } @@ -131,9 +153,8 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna * Fake invisibility if dir belongs to a group/default groups hierarchy * being attached */ - ret = -ENOENT; if (!configfs_dirent_is_ready(sd)) - goto out; + return -ENOENT; parent_item = configfs_get_config_item(dentry->d_parent); type = parent_item->ci_type; @@ -143,11 +164,42 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna !type->ct_item_ops->allow_link) goto out_put; + /* + * This is really sick. What they wanted was a hybrid of + * link(2) and symlink(2) - they wanted the target resolved + * at syscall time (as link(2) would've done), be a directory + * (which link(2) would've refused to do) *AND* be a deep + * fucking magic, making the target busy from rmdir POV. + * symlink(2) is nothing of that sort, and the locking it + * gets matches the normal symlink(2) semantics. Without + * attempts to resolve the target (which might very well + * not even exist yet) done prior to locking the parent + * directory. This perversion, OTOH, needs to resolve + * the target, which would lead to obvious deadlocks if + * attempted with any directories locked. + * + * Unfortunately, that garbage is userland ABI and we should've + * said "no" back in 2005. Too late now, so we get to + * play very ugly games with locking. + * + * Try *ANYTHING* of that sort in new code, and you will + * really regret it. Just ask yourself - what could a BOFH + * do to me and do I want to find it out first-hand? + * + * AV, a thoroughly annoyed bastard. + */ + inode_unlock(dir); ret = get_target(symname, &path, &target_item, dentry->d_sb); + inode_lock(dir); if (ret) goto out_put; - ret = type->ct_item_ops->allow_link(parent_item, target_item); + if (dentry->d_inode || d_unhashed(dentry)) + ret = -EEXIST; + else + ret = inode_permission(dir, MAY_WRITE | MAY_EXEC); + if (!ret) + ret = type->ct_item_ops->allow_link(parent_item, target_item); if (!ret) { mutex_lock(&configfs_symlink_mutex); ret = create_link(parent_item, target_item, dentry); @@ -162,15 +214,12 @@ int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symna out_put: config_item_put(parent_item); - -out: return ret; } int configfs_unlink(struct inode *dir, struct dentry *dentry) { - struct configfs_dirent *sd = dentry->d_fsdata; - struct configfs_symlink *sl; + struct configfs_dirent *sd = dentry->d_fsdata, *target_sd; struct config_item *parent_item; const struct config_item_type *type; int ret; @@ -179,7 +228,7 @@ int configfs_unlink(struct inode *dir, struct dentry *dentry) if (!(sd->s_type & CONFIGFS_ITEM_LINK)) goto out; - sl = sd->s_element; + target_sd = sd->s_element; parent_item = configfs_get_config_item(dentry->d_parent); type = parent_item->ci_type; @@ -193,21 +242,18 @@ int configfs_unlink(struct inode *dir, struct dentry *dentry) /* * drop_link() must be called before - * list_del_init(&sl->sl_list), so that the order of + * decrementing target's ->s_links, so that the order of * drop_link(this, target) and drop_item(target) is preserved. */ if (type && type->ct_item_ops && type->ct_item_ops->drop_link) type->ct_item_ops->drop_link(parent_item, - sl->sl_target); + target_sd->s_element); spin_lock(&configfs_dirent_lock); - list_del_init(&sl->sl_list); + target_sd->s_links--; spin_unlock(&configfs_dirent_lock); - - /* Put reference from create_link() */ - config_item_put(sl->sl_target); - kfree(sl); + configfs_put(target_sd); config_item_put(parent_item); @@ -217,79 +263,8 @@ out: return ret; } -static int configfs_get_target_path(struct config_item * item, struct config_item * target, - char *path) -{ - char * s; - int depth, size; - - depth = item_depth(item); - size = item_path_length(target) + depth * 3 - 1; - if (size > PATH_MAX) - return -ENAMETOOLONG; - - pr_debug("%s: depth = %d, size = %d\n", __func__, depth, size); - - for (s = path; depth--; s += 3) - strcpy(s,"../"); - - fill_item_path(target, path, size); - pr_debug("%s: path = '%s'\n", __func__, path); - - return 0; -} - -static int configfs_getlink(struct dentry *dentry, char * path) -{ - struct config_item *item, *target_item; - int error = 0; - - item = configfs_get_config_item(dentry->d_parent); - if (!item) - return -EINVAL; - - target_item = configfs_get_config_item(dentry); - if (!target_item) { - config_item_put(item); - return -EINVAL; - } - - down_read(&configfs_rename_sem); - error = configfs_get_target_path(item, target_item, path); - up_read(&configfs_rename_sem); - - config_item_put(item); - config_item_put(target_item); - return error; - -} - -static const char *configfs_get_link(struct dentry *dentry, - struct inode *inode, - struct delayed_call *done) -{ - char *body; - int error; - - if (!dentry) - return ERR_PTR(-ECHILD); - - body = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!body) - return ERR_PTR(-ENOMEM); - - error = configfs_getlink(dentry, body); - if (!error) { - set_delayed_call(done, kfree_link, body); - return body; - } - - kfree(body); - return ERR_PTR(error); -} - const struct inode_operations configfs_symlink_inode_operations = { - .get_link = configfs_get_link, + .get_link = simple_get_link, .setattr = configfs_setattr, }; |