From htejun@gmail.com Wed Aug 1 18:02:30 2007 From: Eric W. Biederman Date: Tue, 31 Jul 2007 19:15:08 +0900 Subject: sysfs: Remove first pass at shadow directory support To: ebiederm@xmission.com, gregkh@suse.de, linux-kernel@vger.kernel.org, satyam@infradead.org, cornelia.huck@de.ibm.com, stern@rowland.harvard.edu, htejun@gmail.com Cc: Eric W.Biederman , Tejun Heo Message-ID: <11858769083285-git-send-email-htejun@gmail.com> From: Eric W. Biederman While shadow directories appear to be a good idea, the current scheme of controlling their creation and destruction outside of sysfs appears to be a locking and maintenance nightmare in the face of sysfs directories dynamically coming and going. Which can now occur for directories containing network devices when CONFIG_SYSFS_DEPRECATED is not set. This patch removes everything from the initial shadow directory support that allowed the shadow directory creation to be controlled at a higher level. So except for a few bits of sysfs_rename_dir everything from commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 167 ++++++------------------------------------------ fs/sysfs/group.c | 1 fs/sysfs/inode.c | 10 -- fs/sysfs/mount.c | 2 fs/sysfs/sysfs.h | 6 - include/linux/kobject.h | 5 - include/linux/sysfs.h | 27 +------ lib/kobject.c | 44 +----------- 8 files changed, 33 insertions(+), 229 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -569,9 +569,6 @@ static void sysfs_drop_dentry(struct sys 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 */ @@ -723,19 +720,15 @@ int sysfs_create_subdir(struct kobject * /** * sysfs_create_dir - create a directory for an object. * @kobj: object we're creating directory for. - * @shadow_parent: parent object. */ -int sysfs_create_dir(struct kobject *kobj, - struct sysfs_dirent *shadow_parent_sd) +int sysfs_create_dir(struct kobject * kobj) { struct sysfs_dirent *parent_sd, *sd; int error = 0; BUG_ON(!kobj); - if (shadow_parent_sd) - parent_sd = shadow_parent_sd; - else if (kobj->parent) + if (kobj->parent) parent_sd = kobj->parent->sd; else if (sysfs_mount && sysfs_mount->mnt_sb) parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata; @@ -890,45 +883,44 @@ void sysfs_remove_dir(struct kobject * k __sysfs_remove_dir(sd); } -int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd, - const char *new_name) +int sysfs_rename_dir(struct kobject * kobj, const char *new_name) { - struct sysfs_dirent *sd = kobj->sd; - struct dentry *new_parent = NULL; + struct sysfs_dirent *sd; + struct dentry *parent = NULL; struct dentry *old_dentry = NULL, *new_dentry = NULL; + struct sysfs_dirent *parent_sd; const char *dup_name = NULL; int error; + if (!kobj->parent) + return -EINVAL; + /* get dentries */ + sd = kobj->sd; 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); + parent_sd = kobj->parent->sd; + parent = sysfs_get_dentry(parent_sd); + if (IS_ERR(parent)) { + error = PTR_ERR(parent); goto out_dput; } - /* lock new_parent and get dentry for new name */ - mutex_lock(&new_parent->d_inode->i_mutex); + /* lock parent and get dentry for new name */ + mutex_lock(&parent->d_inode->i_mutex); - new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); + new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); if (IS_ERR(new_dentry)) { error = PTR_ERR(new_dentry); goto out_unlock; } - /* By allowing two different directories with the same - * d_parent we allow this routine to move between different - * shadows of the same directory - */ error = -EINVAL; - if (old_dentry->d_parent->d_inode != new_parent->d_inode || - new_dentry->d_parent->d_inode != new_parent->d_inode || - old_dentry == new_dentry) + if (old_dentry == new_dentry) goto out_unlock; error = -EEXIST; @@ -955,9 +947,9 @@ int sysfs_rename_dir(struct kobject *kob d_move(sd->s_dentry, new_dentry); sysfs_unlink_sibling(sd); - sysfs_get(new_parent_sd); + sysfs_get(parent_sd); sysfs_put(sd->s_parent); - sd->s_parent = new_parent_sd; + sd->s_parent = parent_sd; sysfs_link_sibling(sd); mutex_unlock(&sysfs_mutex); @@ -968,10 +960,10 @@ int sysfs_rename_dir(struct kobject *kob out_drop: d_drop(new_dentry); out_unlock: - mutex_unlock(&new_parent->d_inode->i_mutex); + mutex_unlock(&parent->d_inode->i_mutex); out_dput: kfree(dup_name); - dput(new_parent); + dput(parent); dput(old_dentry); dput(new_dentry); return error; @@ -1192,121 +1184,6 @@ static loff_t sysfs_dir_lseek(struct fil return offset; } - -/** - * sysfs_make_shadowed_dir - Setup so a directory can be shadowed - * @kobj: object we're creating shadow of. - */ - -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; - - /* 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) - return -ENOMEM; - - memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op)); - i_op->follow_link = follow_link; - - /* Locking of inode->i_op? - * Since setting i_op is a single word write and they - * are atomic we should be ok here. - */ - inode->i_op = i_op; - return 0; -} - -/** - * sysfs_create_shadow_dir - create a shadow directory for an object. - * @kobj: object we're creating directory for. - * - * sysfs_make_shadowed_dir must already have been called on this - * directory. - */ - -struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj) -{ - 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; - - 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) - goto nomem; - - sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR); - if (!sd) - goto nomem; - sd->s_elem.dir.kobj = kobj; - - 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); /* tj: synchronization? */ - - sysfs_addrm_finish(&acxt); - - dget(shadow); /* Extra count - pin the dentry in core */ - - goto out_dput; - - nomem: - dput(shadow); - sd = ERR_PTR(-ENOMEM); - out_dput: - dput(dir); - out: - return sd; -} - -/** - * sysfs_remove_shadow_dir - remove an object's 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 sysfs_dirent *shadow_sd) -{ - __sysfs_remove_dir(shadow_sd); -} - const struct file_operations sysfs_dir_operations = { .open = sysfs_dir_open, .release = sysfs_dir_close, --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,7 +13,6 @@ #include #include #include -#include #include "sysfs.h" --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -33,16 +33,6 @@ static const struct inode_operations sys .setattr = sysfs_setattr, }; -void sysfs_delete_inode(struct inode *inode) -{ - /* Free the shadowed directory inode operations */ - if (sysfs_is_shadowed_inode(inode)) { - kfree(inode->i_op); - inode->i_op = NULL; - } - return generic_delete_inode(inode); -} - int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) { struct inode * inode = dentry->d_inode; --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -20,7 +20,7 @@ struct kmem_cache *sysfs_dir_cachep; static const struct super_operations sysfs_ops = { .statfs = simple_statfs, - .drop_inode = sysfs_delete_inode, + .drop_inode = generic_delete_inode, }; struct sysfs_dirent sysfs_root = { --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -70,7 +70,6 @@ extern void sysfs_remove_one(struct sysf struct sysfs_dirent *sd); extern int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); -extern void sysfs_delete_inode(struct inode *inode); extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd); extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode); @@ -121,8 +120,3 @@ static inline void sysfs_put(struct sysf if (sd && atomic_dec_and_test(&sd->s_count)) release_sysfs_dirent(sd); } - -static inline int sysfs_is_shadowed_inode(struct inode *inode) -{ - return S_ISDIR(inode->i_mode) && inode->i_op->follow_link; -} --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -84,14 +84,9 @@ extern void kobject_init(struct kobject extern void kobject_cleanup(struct kobject *); extern int __must_check kobject_add(struct kobject *); -extern int __must_check kobject_shadow_add(struct kobject *kobj, - struct sysfs_dirent *shadow_parent); extern void kobject_del(struct kobject *); extern int __must_check kobject_rename(struct kobject *, const char *new_name); -extern int __must_check kobject_shadow_rename(struct kobject *kobj, - struct sysfs_dirent *new_parent, - const char *new_name); extern int __must_check kobject_move(struct kobject *, struct kobject *); extern int __must_check kobject_register(struct kobject *); --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -17,9 +17,6 @@ struct kobject; struct module; -struct nameidata; -struct dentry; -struct sysfs_dirent; /* FIXME * The *owner field is no longer used, but leave around @@ -94,14 +91,13 @@ extern int sysfs_schedule_callback(struc void (*func)(void *), void *data, struct module *owner); extern int __must_check -sysfs_create_dir(struct kobject *kobj, struct sysfs_dirent *shadow_parent_sd); +sysfs_create_dir(struct kobject *); extern void sysfs_remove_dir(struct kobject *); extern int __must_check -sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd, - const char *new_name); +sysfs_rename_dir(struct kobject *kobj, const char *new_name); extern int __must_check sysfs_move_dir(struct kobject *, struct kobject *); @@ -138,12 +134,6 @@ void sysfs_remove_file_from_group(struct void sysfs_notify(struct kobject * k, char *dir, char *attr); - -extern int sysfs_make_shadowed_dir(struct kobject *kobj, - void * (*follow_link)(struct dentry *, struct nameidata *)); -extern struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj); -extern void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd); - extern int __must_check sysfs_init(void); #else /* CONFIG_SYSFS */ @@ -154,8 +144,7 @@ static inline int sysfs_schedule_callbac return -ENOSYS; } -static inline int sysfs_create_dir(struct kobject *kobj, - struct sysfs_dirent *shadow_parent_sd) +static inline int sysfs_create_dir(struct kobject * kobj) { return 0; } @@ -165,9 +154,7 @@ static inline void sysfs_remove_dir(stru ; } -static inline int sysfs_rename_dir(struct kobject *kobj, - struct sysfs_dirent *new_parent_sd, - const char *new_name) +static inline int sysfs_rename_dir(struct kobject * kobj, const char *new_name) { return 0; } @@ -242,12 +229,6 @@ static inline void sysfs_notify(struct k { } -static inline int sysfs_make_shadowed_dir(struct kobject *kobj, - void * (*follow_link)(struct dentry *, struct nameidata *)) -{ - return 0; -} - static inline int __must_check sysfs_init(void) { return 0; --- a/lib/kobject.c +++ b/lib/kobject.c @@ -44,11 +44,11 @@ static int populate_dir(struct kobject * return error; } -static int create_dir(struct kobject *kobj, struct sysfs_dirent *shadow_parent) +static int create_dir(struct kobject * kobj) { int error = 0; if (kobject_name(kobj)) { - error = sysfs_create_dir(kobj, shadow_parent); + error = sysfs_create_dir(kobj); if (!error) { if ((error = populate_dir(kobj))) sysfs_remove_dir(kobj); @@ -157,12 +157,11 @@ static void unlink(struct kobject * kobj } /** - * kobject_shadow_add - add an object to the hierarchy. + * kobject_add - add an object to the hierarchy. * @kobj: object. - * @shadow_parent: sysfs directory to add to. */ -int kobject_shadow_add(struct kobject *kobj, struct sysfs_dirent *shadow_parent) +int kobject_add(struct kobject * kobj) { int error = 0; struct kobject * parent; @@ -194,7 +193,7 @@ int kobject_shadow_add(struct kobject *k kobj->parent = parent; } - error = create_dir(kobj, shadow_parent); + error = create_dir(kobj); if (error) { /* unlink does the kobject_put() for us */ unlink(kobj); @@ -216,16 +215,6 @@ int kobject_shadow_add(struct kobject *k } /** - * kobject_add - add an object to the hierarchy. - * @kobj: object. - */ -int kobject_add(struct kobject * kobj) -{ - return kobject_shadow_add(kobj, NULL); -} - - -/** * kobject_register - initialize and add an object. * @kobj: object in question. */ @@ -334,7 +323,7 @@ int kobject_rename(struct kobject * kobj /* Note : if we want to send the new name alone, not the full path, * we could probably use kobject_name(kobj); */ - error = sysfs_rename_dir(kobj, kobj->parent->sd, new_name); + error = sysfs_rename_dir(kobj, new_name); /* This function is mostly/only used for network interface. * Some hotplug package track interfaces by their name and @@ -351,27 +340,6 @@ out: } /** - * kobject_rename - change the name of an object - * @kobj: object in question. - * @new_parent: object's new parent - * @new_name: object's new name - */ - -int kobject_shadow_rename(struct kobject *kobj, - struct sysfs_dirent *new_parent, const char *new_name) -{ - int error = 0; - - kobj = kobject_get(kobj); - if (!kobj) - return -EINVAL; - error = sysfs_rename_dir(kobj, new_parent, new_name); - kobject_put(kobj); - - return error; -} - -/** * kobject_move - move object to another parent * @kobj: object in question. * @new_parent: object's new parent (can be NULL)