diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/sysfs/bin.c | 6 | ||||
-rw-r--r-- | fs/sysfs/dir.c | 214 | ||||
-rw-r--r-- | fs/sysfs/file.c | 82 | ||||
-rw-r--r-- | fs/sysfs/group.c | 2 | ||||
-rw-r--r-- | fs/sysfs/inode.c | 36 | ||||
-rw-r--r-- | fs/sysfs/mount.c | 11 | ||||
-rw-r--r-- | fs/sysfs/symlink.c | 1 | ||||
-rw-r--r-- | fs/sysfs/sysfs.h | 21 |
8 files changed, 305 insertions, 68 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index e8f540d..d3b9f5f 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -16,6 +16,7 @@ #include <linux/slab.h> #include <asm/uaccess.h> +#include <asm/semaphore.h> #include "sysfs.h" @@ -146,7 +147,7 @@ static int open(struct inode * inode, struct file * file) Error: module_put(attr->attr.owner); Done: - if (error && kobj) + if (error) kobject_put(kobj); return error; } @@ -157,8 +158,7 @@ static int release(struct inode * inode, struct file * file) struct bin_attribute * attr = to_bin_attr(file->f_path.dentry); u8 * buffer = file->private_data; - if (kobj) - kobject_put(kobj); + kobject_put(kobj); module_put(attr->attr.owner); kfree(buffer); return 0; diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 511edef..9dcdf55 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -9,6 +9,7 @@ #include <linux/module.h> #include <linux/kobject.h> #include <linux/namei.h> +#include <asm/semaphore.h> #include "sysfs.h" DECLARE_RWSEM(sysfs_rename_sem); @@ -32,8 +33,7 @@ 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(struct sysfs_dirent * parent_sd, - void * element) +static struct sysfs_dirent * __sysfs_new_dirent(void * element) { struct sysfs_dirent * sd; @@ -45,12 +45,28 @@ static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd, atomic_set(&sd->s_count, 1); atomic_set(&sd->s_event, 1); INIT_LIST_HEAD(&sd->s_children); - list_add(&sd->s_sibling, &parent_sd->s_children); + INIT_LIST_HEAD(&sd->s_sibling); 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 @@ -77,14 +93,14 @@ int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, } -int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, - void * element, umode_t mode, int type) +static struct sysfs_dirent * +__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type) { struct sysfs_dirent * sd; - sd = sysfs_new_dirent(parent_sd, element); + sd = __sysfs_new_dirent(element); if (!sd) - return -ENOMEM; + goto out; sd->s_mode = mode; sd->s_type = type; @@ -94,7 +110,19 @@ int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, dentry->d_op = &sysfs_dentry_ops; } - return 0; +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; } static int init_dir(struct inode * inode) @@ -165,11 +193,11 @@ int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) /** * sysfs_create_dir - create a directory for an object. - * @parent: parent parent object. * @kobj: object we're creating directory for. + * @shadow_parent: parent parent object. */ -int sysfs_create_dir(struct kobject * kobj) +int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent) { struct dentry * dentry = NULL; struct dentry * parent; @@ -177,7 +205,9 @@ int sysfs_create_dir(struct kobject * kobj) BUG_ON(!kobj); - if (kobj->parent) + if (shadow_parent) + parent = shadow_parent; + else if (kobj->parent) parent = kobj->parent->dentry; else if (sysfs_mount && sysfs_mount->mnt_sb) parent = sysfs_mount->mnt_sb->s_root; @@ -298,21 +328,12 @@ void sysfs_remove_subdir(struct dentry * d) } -/** - * 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) +static void __sysfs_remove_dir(struct dentry *dentry) { - struct dentry * dentry = dget(kobj->dentry); struct sysfs_dirent * parent_sd; struct sysfs_dirent * sd, * tmp; + dget(dentry); if (!dentry) return; @@ -333,32 +354,60 @@ void sysfs_remove_dir(struct kobject * kobj) * 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, const char *new_name) +int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, + const char *new_name) { int error = 0; - struct dentry * new_dentry, * parent; - - if (!strcmp(kobject_name(kobj), new_name)) - return -EINVAL; + struct dentry * new_dentry; - if (!kobj->parent) - return -EINVAL; + if (!new_parent) + return -EFAULT; down_write(&sysfs_rename_sem); - parent = kobj->parent->dentry; - - mutex_lock(&parent->d_inode->i_mutex); + mutex_lock(&new_parent->d_inode->i_mutex); - new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); + new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); if (!IS_ERR(new_dentry)) { - if (!new_dentry->d_inode) { + /* 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) + error = -EINVAL; + else if (!new_dentry->d_inode) { error = kobject_set_name(kobj, "%s", new_name); if (!error) { + struct sysfs_dirent *sd, *parent_sd; + d_add(new_dentry, NULL); d_move(kobj->dentry, new_dentry); + + sd = kobj->dentry->d_fsdata; + parent_sd = new_parent->d_fsdata; + + list_del_init(&sd->s_sibling); + list_add(&sd->s_sibling, &parent_sd->s_children); } else d_drop(new_dentry); @@ -366,7 +415,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name) error = -EEXIST; dput(new_dentry); } - mutex_unlock(&parent->d_inode->i_mutex); + mutex_unlock(&new_parent->d_inode->i_mutex); up_write(&sysfs_rename_sem); return error; @@ -378,12 +427,10 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent) struct sysfs_dirent *new_parent_sd, *sd; int error; - if (!new_parent) - return -EINVAL; - old_parent_dentry = kobj->parent ? kobj->parent->dentry : sysfs_mount->mnt_sb->s_root; - new_parent_dentry = new_parent->dentry; + new_parent_dentry = new_parent ? + new_parent->dentry : sysfs_mount->mnt_sb->s_root; again: mutex_lock(&old_parent_dentry->d_inode->i_mutex); @@ -547,6 +594,95 @@ 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/file.c b/fs/sysfs/file.c index 9cfe53e..c0e1176 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -7,6 +7,7 @@ #include <linux/kobject.h> #include <linux/namei.h> #include <linux/poll.h> +#include <linux/list.h> #include <asm/uaccess.h> #include <asm/semaphore.h> @@ -50,17 +51,29 @@ static struct sysfs_ops subsys_sysfs_ops = { .store = subsys_attr_store, }; +/** + * add_to_collection - add buffer to a collection + * @buffer: buffer to be added + * @node inode of set to add to + */ -struct sysfs_buffer { - size_t count; - loff_t pos; - char * page; - struct sysfs_ops * ops; - struct semaphore sem; - int needs_read_fill; - int event; -}; +static inline void +add_to_collection(struct sysfs_buffer *buffer, struct inode *node) +{ + struct sysfs_buffer_collection *set = node->i_private; + mutex_lock(&node->i_mutex); + list_add(&buffer->associates, &set->associates); + mutex_unlock(&node->i_mutex); +} + +static inline void +remove_from_collection(struct sysfs_buffer *buffer, struct inode *node) +{ + mutex_lock(&node->i_mutex); + list_del(&buffer->associates); + mutex_unlock(&node->i_mutex); +} /** * fill_read_buffer - allocate and fill buffer from object. @@ -70,7 +83,8 @@ struct sysfs_buffer { * Allocate @buffer->page, if it hasn't been already, then call the * kobject's show() method to fill the buffer with this attribute's * data. - * This is called only once, on the file's first read. + * This is called only once, on the file's first read unless an error + * is returned. */ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer) { @@ -88,12 +102,13 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer buffer->event = atomic_read(&sd->s_event); count = ops->show(kobj,attr,buffer->page); - buffer->needs_read_fill = 0; BUG_ON(count > (ssize_t)PAGE_SIZE); - if (count >= 0) + if (count >= 0) { + buffer->needs_read_fill = 0; buffer->count = count; - else + } else { ret = count; + } return ret; } @@ -153,6 +168,10 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) ssize_t retval = 0; down(&buffer->sem); + if (buffer->orphaned) { + retval = -ENODEV; + goto out; + } if (buffer->needs_read_fill) { if ((retval = fill_read_buffer(file->f_path.dentry,buffer))) goto out; @@ -165,7 +184,6 @@ out: return retval; } - /** * fill_write_buffer - copy buffer from userspace. * @buffer: data buffer for file. @@ -243,19 +261,25 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t ssize_t len; down(&buffer->sem); + if (buffer->orphaned) { + len = -ENODEV; + goto out; + } len = fill_write_buffer(buffer, buf, count); if (len > 0) len = flush_write_buffer(file->f_path.dentry, buffer, len); if (len > 0) *ppos += len; +out: up(&buffer->sem); return len; } -static int check_perm(struct inode * inode, struct file * file) +static int sysfs_open_file(struct inode *inode, struct file *file) { struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent); struct attribute * attr = to_attr(file->f_path.dentry); + struct sysfs_buffer_collection *set; struct sysfs_buffer * buffer; struct sysfs_ops * ops = NULL; int error = 0; @@ -285,6 +309,18 @@ static int check_perm(struct inode * inode, struct file * file) if (!ops) goto Eaccess; + /* make sure we have a collection to add our buffers to */ + mutex_lock(&inode->i_mutex); + if (!(set = inode->i_private)) { + if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL))) { + error = -ENOMEM; + goto Done; + } else { + INIT_LIST_HEAD(&set->associates); + } + } + mutex_unlock(&inode->i_mutex); + /* File needs write support. * The inode's perms must say it's ok, * and we must have a store method. @@ -310,9 +346,11 @@ static int check_perm(struct inode * inode, struct file * file) */ buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL); if (buffer) { + INIT_LIST_HEAD(&buffer->associates); init_MUTEX(&buffer->sem); buffer->needs_read_fill = 1; buffer->ops = ops; + add_to_collection(buffer, inode); file->private_data = buffer; } else error = -ENOMEM; @@ -325,16 +363,11 @@ static int check_perm(struct inode * inode, struct file * file) error = -EACCES; module_put(attr->owner); Done: - if (error && kobj) + if (error) kobject_put(kobj); return error; } -static int sysfs_open_file(struct inode * inode, struct file * filp) -{ - return check_perm(inode,filp); -} - static int sysfs_release(struct inode * inode, struct file * filp) { struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent); @@ -342,8 +375,9 @@ static int sysfs_release(struct inode * inode, struct file * filp) struct module * owner = attr->owner; struct sysfs_buffer * buffer = filp->private_data; - if (kobj) - kobject_put(kobj); + if (buffer) + remove_from_collection(buffer, inode); + kobject_put(kobj); /* After this point, attr should not be accessed. */ module_put(owner); @@ -548,7 +582,7 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file); void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr) { - sysfs_hash_and_remove(kobj->dentry,attr->name); + sysfs_hash_and_remove(kobj->dentry, attr->name); } diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 122145b..b20951c 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,6 +13,8 @@ #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 e79e38d..542d2bc 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -13,6 +13,7 @@ #include <linux/backing-dev.h> #include <linux/capability.h> #include <linux/errno.h> +#include <asm/semaphore.h> #include "sysfs.h" extern struct super_block * sysfs_sb; @@ -32,6 +33,16 @@ static 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; @@ -209,6 +220,22 @@ const unsigned char * sysfs_get_name(struct sysfs_dirent *sd) return NULL; } +static inline void orphan_all_buffers(struct inode *node) +{ + struct sysfs_buffer_collection *set = node->i_private; + struct sysfs_buffer *buf; + + mutex_lock_nested(&node->i_mutex, I_MUTEX_CHILD); + if (node->i_private) { + list_for_each_entry(buf, &set->associates, associates) { + down(&buf->sem); + buf->orphaned = 1; + up(&buf->sem); + } + } + mutex_unlock(&node->i_mutex); +} + /* * Unhashes the dentry corresponding to given sysfs_dirent @@ -217,16 +244,23 @@ const unsigned char * sysfs_get_name(struct sysfs_dirent *sd) void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent) { struct dentry * dentry = sd->s_dentry; + struct inode *inode; if (dentry) { spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry) && dentry->d_inode)) { + inode = dentry->d_inode; + spin_lock(&inode->i_lock); + __iget(inode); + spin_unlock(&inode->i_lock); dget_locked(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, dentry); + orphan_all_buffers(inode); + iput(inode); } else { spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); @@ -248,7 +282,7 @@ int sysfs_hash_and_remove(struct dentry * dir, const char * name) return -ENOENT; parent_sd = dir->d_fsdata; - mutex_lock(&dir->d_inode->i_mutex); + mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { if (!sd->s_element) continue; diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index e503f85..f6a87a8 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -8,6 +8,7 @@ #include <linux/mount.h> #include <linux/pagemap.h> #include <linux/init.h> +#include <asm/semaphore.h> #include "sysfs.h" @@ -18,9 +19,12 @@ struct vfsmount *sysfs_mount; struct super_block * sysfs_sb = NULL; struct kmem_cache *sysfs_dir_cachep; +static void sysfs_clear_inode(struct inode *inode); + static struct super_operations sysfs_ops = { .statfs = simple_statfs, - .drop_inode = generic_delete_inode, + .drop_inode = sysfs_delete_inode, + .clear_inode = sysfs_clear_inode, }; static struct sysfs_dirent sysfs_root = { @@ -31,6 +35,11 @@ static struct sysfs_dirent sysfs_root = { .s_iattr = NULL, }; +static void sysfs_clear_inode(struct inode *inode) +{ + kfree(inode->i_private); +} + static int sysfs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *inode; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index f50e3cc..4869f61 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -7,6 +7,7 @@ #include <linux/module.h> #include <linux/kobject.h> #include <linux/namei.h> +#include <asm/semaphore.h> #include "sysfs.h" diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index bd7cec2..fe1cbfd 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -2,6 +2,7 @@ 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 *)); @@ -33,6 +34,22 @@ struct sysfs_symlink { struct kobject * target_kobj; }; +struct sysfs_buffer { + struct list_head associates; + size_t count; + loff_t pos; + char * page; + struct sysfs_ops * ops; + struct semaphore sem; + int orphaned; + int needs_read_fill; + int event; +}; + +struct sysfs_buffer_collection { + struct list_head associates; +}; + static inline struct kobject * to_kobj(struct dentry * dentry) { struct sysfs_dirent * sd = dentry->d_fsdata; @@ -96,3 +113,7 @@ 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; +} |