Messages in this thread Patch in this message | | | From | (Eric W. Biederman) | Subject | [PATCH 2/5] sysfs: Remove first pass at shadow directory support | Date | Fri, 06 Apr 2007 10:48:42 -0600 |
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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 <ebiederm@xmission.com> --- fs/sysfs/dir.c | 196 +++++++++-------------------------------------- fs/sysfs/group.c | 1 - fs/sysfs/inode.c | 10 --- fs/sysfs/mount.c | 2 +- fs/sysfs/sysfs.h | 5 - include/linux/kobject.h | 4 - include/linux/sysfs.h | 24 +----- lib/kobject.c | 43 +--------- 8 files changed, 45 insertions(+), 240 deletions(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 85a6686..d6ab015 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -33,7 +33,8 @@ static struct dentry_operations sysfs_dentry_ops = { /* * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent */ -static struct sysfs_dirent * __sysfs_new_dirent(void * element) +static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd, + void * element) { struct sysfs_dirent * sd; @@ -44,28 +45,12 @@ static struct sysfs_dirent * __sysfs_new_dirent(void * element) atomic_set(&sd->s_count, 1); atomic_set(&sd->s_event, 1); INIT_LIST_HEAD(&sd->s_children); - INIT_LIST_HEAD(&sd->s_sibling); + list_add(&sd->s_sibling, &parent_sd->s_children); sd->s_element = element; return sd; } -static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd, - struct sysfs_dirent *sd) -{ - if (sd) - list_add(&sd->s_sibling, &parent_sd->s_children); -} - -static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd, - void * element) -{ - struct sysfs_dirent *sd; - sd = __sysfs_new_dirent(element); - __sysfs_list_dirent(parent_sd, sd); - return sd; -} - /* * * Return -EEXIST if there is already a sysfs element with the same name for @@ -92,14 +77,14 @@ int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, } -static struct sysfs_dirent * -__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type) +int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, + void * element, umode_t mode, int type) { struct sysfs_dirent * sd; - sd = __sysfs_new_dirent(element); + sd = sysfs_new_dirent(parent_sd, element); if (!sd) - goto out; + return -ENOMEM; sd->s_mode = mode; sd->s_type = type; @@ -109,19 +94,7 @@ __sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type) dentry->d_op = &sysfs_dentry_ops; } -out: - return sd; -} - -int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, - void * element, umode_t mode, int type) -{ - struct sysfs_dirent *sd; - - sd = __sysfs_make_dirent(dentry, element, mode, type); - __sysfs_list_dirent(parent_sd, sd); - - return sd ? 0 : -ENOMEM; + return 0; } static int init_dir(struct inode * inode) @@ -193,10 +166,9 @@ int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) /** * sysfs_create_dir - create a directory for an object. * @kobj: object we're creating directory for. - * @shadow_parent: parent parent object. */ -int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent) +int sysfs_create_dir(struct kobject * kobj) { struct dentry * dentry = NULL; struct dentry * parent; @@ -204,9 +176,7 @@ int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent) BUG_ON(!kobj); - if (shadow_parent) - parent = shadow_parent; - else if (kobj->parent) + if (kobj->parent) parent = kobj->parent->dentry; else if (sysfs_mount && sysfs_mount->mnt_sb) parent = sysfs_mount->mnt_sb->s_root; @@ -327,12 +297,21 @@ void sysfs_remove_subdir(struct dentry * d) } -static void __sysfs_remove_dir(struct dentry *dentry) +/** + * sysfs_remove_dir - remove an object's directory. + * @kobj: object. + * + * 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_dir(struct kobject * kobj) { + struct dentry * dentry = dget(kobj->dentry); struct sysfs_dirent * parent_sd; struct sysfs_dirent * sd, * tmp; - dget(dentry); if (!dentry) return; @@ -353,46 +332,28 @@ static void __sysfs_remove_dir(struct dentry *dentry) * Drop reference from dget() on entrance. */ dput(dentry); -} - -/** - * sysfs_remove_dir - remove an object's directory. - * @kobj: object. - * - * 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_dir(struct kobject * kobj) -{ - __sysfs_remove_dir(kobj->dentry); kobj->dentry = NULL; } -int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, - const char *new_name) +int sysfs_rename_dir(struct kobject * kobj, const char *new_name) { int error = 0; - struct dentry * new_dentry; + struct inode * inode; + struct dentry * new_dentry, * old_parent, * new_parent; - if (!new_parent) - return -EFAULT; + if (!kobj->parent) + return -EINVAL; + + old_parent = dget(kobj->dentry->d_parent); + inode = old_parent->d_inode; down_write(&sysfs_rename_sem); - mutex_lock(&new_parent->d_inode->i_mutex); + mutex_lock(&inode->i_mutex); + new_parent = kobj->dentry->d_parent; new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); if (!IS_ERR(new_dentry)) { - /* By allowing two different directories with the - * same d_parent we allow this routine to move - * between different shadows of the same directory - */ - if (kobj->dentry->d_parent->d_inode != new_parent->d_inode) - return -EINVAL; - else if (new_dentry->d_parent->d_inode != new_parent->d_inode) - error = -EINVAL; - else if (new_dentry == kobj->dentry) + if (new_dentry == kobj->dentry) error = -EINVAL; else if (!new_dentry->d_inode) { error = kobject_set_name(kobj, "%s", new_name); @@ -414,9 +375,11 @@ int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, error = -EEXIST; dput(new_dentry); } - mutex_unlock(&new_parent->d_inode->i_mutex); + mutex_unlock(&inode->i_mutex); up_write(&sysfs_rename_sem); + dput(old_parent); + return error; } @@ -595,95 +558,6 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) 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 inode *inode; - struct inode_operations *i_op; - - inode = kobj->dentry->d_inode; - if (inode->i_op != &sysfs_dir_inode_operations) - 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 dentry *sysfs_create_shadow_dir(struct kobject *kobj) -{ - struct sysfs_dirent *sd; - struct dentry *parent, *dir, *shadow; - struct inode *inode; - - dir = kobj->dentry; - inode = dir->d_inode; - parent = dir->d_parent; - shadow = ERR_PTR(-EINVAL); - if (!sysfs_is_shadowed_inode(inode)) - goto out; - - shadow = d_alloc(parent, &dir->d_name); - if (!shadow) - goto nomem; - - sd = __sysfs_make_dirent(shadow, kobj, inode->i_mode, SYSFS_DIR); - if (!sd) - goto nomem; - - d_instantiate(shadow, igrab(inode)); - inc_nlink(inode); - inc_nlink(parent->d_inode); - shadow->d_op = &sysfs_dentry_ops; - - dget(shadow); /* Extra count - pin the dentry in core */ - -out: - return shadow; -nomem: - dput(shadow); - shadow = ERR_PTR(-ENOMEM); - goto out; -} - -/** - * sysfs_remove_shadow_dir - remove an object's directory. - * @shadow: dentry 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) -{ - __sysfs_remove_dir(shadow); -} - const struct file_operations sysfs_dir_operations = { .open = sysfs_dir_open, .release = sysfs_dir_close, diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index b20951c..46a277b 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,7 +13,6 @@ #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> -#include <linux/fs.h> #include <asm/semaphore.h> #include "sysfs.h" diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 4de5c6b..69e6e9b 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -33,16 +33,6 @@ static const struct inode_operations sysfs_inode_operations ={ .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; diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 23a48a3..7978cf2 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -23,7 +23,7 @@ static void sysfs_clear_inode(struct inode *inode); static const struct super_operations sysfs_ops = { .statfs = simple_statfs, - .drop_inode = sysfs_delete_inode, + .drop_inode = generic_delete_inode, .clear_inode = sysfs_clear_inode, }; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index a77c57e..ce6b3ec 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -13,7 +13,6 @@ struct sysfs_dirent { extern struct vfsmount * sysfs_mount; extern struct kmem_cache *sysfs_dir_cachep; -extern void sysfs_delete_inode(struct inode *inode); extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *); extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *)); @@ -124,7 +123,3 @@ static inline void sysfs_put(struct sysfs_dirent * sd) 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; -} diff --git a/include/linux/kobject.h b/include/linux/kobject.h index d37cd7f..c96d243 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -74,13 +74,9 @@ 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 *, struct dentry *); 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 dentry *new_parent, - const char *new_name); extern int __must_check kobject_move(struct kobject *, struct kobject *); extern int __must_check kobject_register(struct kobject *); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index fea9a6b..1f1bb45 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -17,8 +17,6 @@ struct kobject; struct module; -struct nameidata; -struct dentry; struct attribute { const char * name; @@ -83,13 +81,13 @@ extern int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), void *data); extern int __must_check -sysfs_create_dir(struct kobject *, struct dentry *); +sysfs_create_dir(struct kobject *); extern void sysfs_remove_dir(struct kobject *); extern int __must_check -sysfs_rename_dir(struct kobject *, struct dentry *, const char *new_name); +sysfs_rename_dir(struct kobject *, const char *new_name); extern int __must_check sysfs_move_dir(struct kobject *, struct kobject *); @@ -126,12 +124,6 @@ void sysfs_remove_file_from_group(struct kobject *kobj, 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 dentry *sysfs_create_shadow_dir(struct kobject *kobj); -extern void sysfs_remove_shadow_dir(struct dentry *dir); - extern int __must_check sysfs_init(void); #else /* CONFIG_SYSFS */ @@ -142,7 +134,7 @@ static inline int sysfs_schedule_callback(struct kobject *kobj, return -ENOSYS; } -static inline int sysfs_create_dir(struct kobject * k, struct dentry *shadow) +static inline int sysfs_create_dir(struct kobject * k) { return 0; } @@ -152,9 +144,7 @@ static inline void sysfs_remove_dir(struct kobject * k) ; } -static inline int sysfs_rename_dir(struct kobject * k, - struct dentry *new_parent, - const char *new_name) +static inline int sysfs_rename_dir(struct kobject * k, const char *new_name) { return 0; } @@ -229,12 +219,6 @@ static inline void sysfs_notify(struct kobject * k, char *dir, char *attr) { } -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; diff --git a/lib/kobject.c b/lib/kobject.c index 09cb276..f590ad8 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -44,11 +44,11 @@ static int populate_dir(struct kobject * kobj) return error; } -static int create_dir(struct kobject * kobj, struct dentry *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); @@ -159,10 +159,9 @@ static void unlink(struct kobject * kobj) /** * 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 dentry *shadow_parent) +int kobject_add(struct kobject * kobj) { int error = 0; struct kobject * parent; @@ -193,7 +192,7 @@ int kobject_shadow_add(struct kobject * kobj, struct dentry *shadow_parent) } kobj->parent = parent; - error = create_dir(kobj, shadow_parent); + error = create_dir(kobj); if (error) { /* unlink does the kobject_put() for us */ unlink(kobj); @@ -214,15 +213,6 @@ int kobject_shadow_add(struct kobject * kobj, struct dentry *shadow_parent) return error; } -/** - * 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. @@ -315,30 +305,7 @@ int kobject_rename(struct kobject * kobj, const char *new_name) kobj = kobject_get(kobj); if (!kobj) return -EINVAL; - if (!kobj->parent) - return -EINVAL; - error = sysfs_rename_dir(kobj, kobj->parent->dentry, new_name); - kobject_put(kobj); - - return error; -} - -/** - * 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 dentry *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); + error = sysfs_rename_dir(kobj, new_name); kobject_put(kobj); return error; -- 1.5.0.g53756 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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