diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/Makefile | 3 | ||||
| -rw-r--r-- | fs/sysfs/bin.c | 502 | ||||
| -rw-r--r-- | fs/sysfs/dir.c | 350 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 872 | ||||
| -rw-r--r-- | fs/sysfs/group.c | 33 | ||||
| -rw-r--r-- | fs/sysfs/inode.c | 30 | ||||
| -rw-r--r-- | fs/sysfs/symlink.c | 50 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 71 |
8 files changed, 901 insertions, 1010 deletions
diff --git a/fs/sysfs/Makefile b/fs/sysfs/Makefile index 7a1ceb9..8876ac1 100644 --- a/fs/sysfs/Makefile +++ b/fs/sysfs/Makefile @@ -2,5 +2,4 @@ # Makefile for the sysfs virtual filesystem # -obj-y := inode.o file.o dir.o symlink.o mount.o bin.o \ - group.o +obj-y := inode.o file.o dir.o symlink.o mount.o group.o diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c deleted file mode 100644 index c590cab..0000000 --- a/fs/sysfs/bin.c +++ /dev/null @@ -1,502 +0,0 @@ -/* - * fs/sysfs/bin.c - sysfs binary file implementation - * - * Copyright (c) 2003 Patrick Mochel - * Copyright (c) 2003 Matthew Wilcox - * Copyright (c) 2004 Silicon Graphics, Inc. - * Copyright (c) 2007 SUSE Linux Products GmbH - * Copyright (c) 2007 Tejun Heo <teheo@suse.de> - * - * This file is released under the GPLv2. - * - * Please see Documentation/filesystems/sysfs.txt for more information. - */ - -#undef DEBUG - -#include <linux/errno.h> -#include <linux/fs.h> -#include <linux/kernel.h> -#include <linux/kobject.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/mutex.h> -#include <linux/mm.h> -#include <linux/uaccess.h> - -#include "sysfs.h" - -/* - * There's one bin_buffer for each open file. - * - * filp->private_data points to bin_buffer and - * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s - * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock - */ -static DEFINE_MUTEX(sysfs_bin_lock); - -struct bin_buffer { - struct mutex mutex; - void *buffer; - int mmapped; - const struct vm_operations_struct *vm_ops; - struct file *file; - struct hlist_node list; -}; - -static int -fill_read(struct file *file, char *buffer, loff_t off, size_t count) -{ - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - int rc; - - /* need attr_sd for attr, its parent for kobj */ - if (!sysfs_get_active(attr_sd)) - return -ENODEV; - - rc = -EIO; - if (attr->read) - rc = attr->read(file, kobj, attr, buffer, off, count); - - sysfs_put_active(attr_sd); - - return rc; -} - -static ssize_t -read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) -{ - struct bin_buffer *bb = file->private_data; - int size = file_inode(file)->i_size; - loff_t offs = *off; - int count = min_t(size_t, bytes, PAGE_SIZE); - char *temp; - - if (!bytes) - return 0; - - if (size) { - if (offs > size) - return 0; - if (offs + count > size) - count = size - offs; - } - - temp = kmalloc(count, GFP_KERNEL); - if (!temp) - return -ENOMEM; - - mutex_lock(&bb->mutex); - - count = fill_read(file, bb->buffer, offs, count); - if (count < 0) { - mutex_unlock(&bb->mutex); - goto out_free; - } - - memcpy(temp, bb->buffer, count); - - mutex_unlock(&bb->mutex); - - if (copy_to_user(userbuf, temp, count)) { - count = -EFAULT; - goto out_free; - } - - pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); - - *off = offs + count; - - out_free: - kfree(temp); - return count; -} - -static int -flush_write(struct file *file, char *buffer, loff_t offset, size_t count) -{ - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - int rc; - - /* need attr_sd for attr, its parent for kobj */ - if (!sysfs_get_active(attr_sd)) - return -ENODEV; - - rc = -EIO; - if (attr->write) - rc = attr->write(file, kobj, attr, buffer, offset, count); - - sysfs_put_active(attr_sd); - - return rc; -} - -static ssize_t write(struct file *file, const char __user *userbuf, - size_t bytes, loff_t *off) -{ - struct bin_buffer *bb = file->private_data; - int size = file_inode(file)->i_size; - loff_t offs = *off; - int count = min_t(size_t, bytes, PAGE_SIZE); - char *temp; - - if (!bytes) - return 0; - - if (size) { - if (offs > size) - return 0; - if (offs + count > size) - count = size - offs; - } - - temp = memdup_user(userbuf, count); - if (IS_ERR(temp)) - return PTR_ERR(temp); - - mutex_lock(&bb->mutex); - - memcpy(bb->buffer, temp, count); - - count = flush_write(file, bb->buffer, offs, count); - mutex_unlock(&bb->mutex); - - if (count > 0) - *off = offs + count; - - kfree(temp); - return count; -} - -static void bin_vma_open(struct vm_area_struct *vma) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - - if (!bb->vm_ops) - return; - - if (!sysfs_get_active(attr_sd)) - return; - - if (bb->vm_ops->open) - bb->vm_ops->open(vma); - - sysfs_put_active(attr_sd); -} - -static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - int ret; - - if (!bb->vm_ops) - return VM_FAULT_SIGBUS; - - if (!sysfs_get_active(attr_sd)) - return VM_FAULT_SIGBUS; - - ret = VM_FAULT_SIGBUS; - if (bb->vm_ops->fault) - ret = bb->vm_ops->fault(vma, vmf); - - sysfs_put_active(attr_sd); - return ret; -} - -static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - int ret; - - if (!bb->vm_ops) - return VM_FAULT_SIGBUS; - - if (!sysfs_get_active(attr_sd)) - return VM_FAULT_SIGBUS; - - ret = 0; - if (bb->vm_ops->page_mkwrite) - ret = bb->vm_ops->page_mkwrite(vma, vmf); - else - file_update_time(file); - - sysfs_put_active(attr_sd); - return ret; -} - -static int bin_access(struct vm_area_struct *vma, unsigned long addr, - void *buf, int len, int write) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - int ret; - - if (!bb->vm_ops) - return -EINVAL; - - if (!sysfs_get_active(attr_sd)) - return -EINVAL; - - ret = -EINVAL; - if (bb->vm_ops->access) - ret = bb->vm_ops->access(vma, addr, buf, len, write); - - sysfs_put_active(attr_sd); - return ret; -} - -#ifdef CONFIG_NUMA -static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - int ret; - - if (!bb->vm_ops) - return 0; - - if (!sysfs_get_active(attr_sd)) - return -EINVAL; - - ret = 0; - if (bb->vm_ops->set_policy) - ret = bb->vm_ops->set_policy(vma, new); - - sysfs_put_active(attr_sd); - return ret; -} - -static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, - unsigned long addr) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct mempolicy *pol; - - if (!bb->vm_ops) - return vma->vm_policy; - - if (!sysfs_get_active(attr_sd)) - return vma->vm_policy; - - pol = vma->vm_policy; - if (bb->vm_ops->get_policy) - pol = bb->vm_ops->get_policy(vma, addr); - - sysfs_put_active(attr_sd); - return pol; -} - -static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, - const nodemask_t *to, unsigned long flags) -{ - struct file *file = vma->vm_file; - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - int ret; - - if (!bb->vm_ops) - return 0; - - if (!sysfs_get_active(attr_sd)) - return 0; - - ret = 0; - if (bb->vm_ops->migrate) - ret = bb->vm_ops->migrate(vma, from, to, flags); - - sysfs_put_active(attr_sd); - return ret; -} -#endif - -static const struct vm_operations_struct bin_vm_ops = { - .open = bin_vma_open, - .fault = bin_fault, - .page_mkwrite = bin_page_mkwrite, - .access = bin_access, -#ifdef CONFIG_NUMA - .set_policy = bin_set_policy, - .get_policy = bin_get_policy, - .migrate = bin_migrate, -#endif -}; - -static int mmap(struct file *file, struct vm_area_struct *vma) -{ - struct bin_buffer *bb = file->private_data; - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - int rc; - - mutex_lock(&bb->mutex); - - /* need attr_sd for attr, its parent for kobj */ - rc = -ENODEV; - if (!sysfs_get_active(attr_sd)) - goto out_unlock; - - rc = -EINVAL; - if (!attr->mmap) - goto out_put; - - rc = attr->mmap(file, kobj, attr, vma); - if (rc) - goto out_put; - - /* - * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() - * to satisfy versions of X which crash if the mmap fails: that - * substitutes a new vm_file, and we don't then want bin_vm_ops. - */ - if (vma->vm_file != file) - goto out_put; - - rc = -EINVAL; - if (bb->mmapped && bb->vm_ops != vma->vm_ops) - goto out_put; - - /* - * It is not possible to successfully wrap close. - * So error if someone is trying to use close. - */ - rc = -EINVAL; - if (vma->vm_ops && vma->vm_ops->close) - goto out_put; - - rc = 0; - bb->mmapped = 1; - bb->vm_ops = vma->vm_ops; - vma->vm_ops = &bin_vm_ops; -out_put: - sysfs_put_active(attr_sd); -out_unlock: - mutex_unlock(&bb->mutex); - - return rc; -} - -static int open(struct inode *inode, struct file *file) -{ - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; - struct bin_buffer *bb = NULL; - int error; - - /* binary file operations requires both @sd and its parent */ - if (!sysfs_get_active(attr_sd)) - return -ENODEV; - - error = -EACCES; - if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) - goto err_out; - if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) - goto err_out; - - error = -ENOMEM; - bb = kzalloc(sizeof(*bb), GFP_KERNEL); - if (!bb) - goto err_out; - - bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!bb->buffer) - goto err_out; - - mutex_init(&bb->mutex); - bb->file = file; - file->private_data = bb; - - mutex_lock(&sysfs_bin_lock); - hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers); - mutex_unlock(&sysfs_bin_lock); - - /* open succeeded, put active references */ - sysfs_put_active(attr_sd); - return 0; - - err_out: - sysfs_put_active(attr_sd); - kfree(bb); - return error; -} - -static int release(struct inode *inode, struct file *file) -{ - struct bin_buffer *bb = file->private_data; - - mutex_lock(&sysfs_bin_lock); - hlist_del(&bb->list); - mutex_unlock(&sysfs_bin_lock); - - kfree(bb->buffer); - kfree(bb); - return 0; -} - -const struct file_operations bin_fops = { - .read = read, - .write = write, - .mmap = mmap, - .llseek = generic_file_llseek, - .open = open, - .release = release, -}; - - -void unmap_bin_file(struct sysfs_dirent *attr_sd) -{ - struct bin_buffer *bb; - - if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR) - return; - - mutex_lock(&sysfs_bin_lock); - - hlist_for_each_entry(bb, &attr_sd->s_bin_attr.buffers, list) { - struct inode *inode = file_inode(bb->file); - - unmap_mapping_range(inode->i_mapping, 0, 0, 1); - } - - mutex_unlock(&sysfs_bin_lock); -} - -/** - * sysfs_create_bin_file - create binary file for object. - * @kobj: object. - * @attr: attribute descriptor. - */ -int sysfs_create_bin_file(struct kobject *kobj, - const struct bin_attribute *attr) -{ - BUG_ON(!kobj || !kobj->sd || !attr); - - return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); -} -EXPORT_SYMBOL_GPL(sysfs_create_bin_file); - -/** - * sysfs_remove_bin_file - remove binary file for object. - * @kobj: object. - * @attr: attribute descriptor. - */ -void sysfs_remove_bin_file(struct kobject *kobj, - const struct bin_attribute *attr) -{ - sysfs_hash_and_remove(kobj->sd, NULL, attr->attr.name); -} -EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 4d83ced..5e73d66 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -26,21 +26,21 @@ #include "sysfs.h" DEFINE_MUTEX(sysfs_mutex); -DEFINE_SPINLOCK(sysfs_assoc_lock); +DEFINE_SPINLOCK(sysfs_symlink_target_lock); -#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb); +#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb) static DEFINE_SPINLOCK(sysfs_ino_lock); static DEFINE_IDA(sysfs_ino_ida); /** * sysfs_name_hash - * @ns: Namespace tag to hash * @name: Null terminated string to hash + * @ns: Namespace tag to hash * * Returns 31 bit hash of ns + name (so it fits in an off_t ) */ -static unsigned int sysfs_name_hash(const void *ns, const char *name) +static unsigned int sysfs_name_hash(const char *name, const void *ns) { unsigned long hash = init_name_hash(); unsigned int len = strlen(name); @@ -56,8 +56,8 @@ static unsigned int sysfs_name_hash(const void *ns, const char *name) return hash; } -static int sysfs_name_compare(unsigned int hash, const void *ns, - const char *name, const struct sysfs_dirent *sd) +static int sysfs_name_compare(unsigned int hash, const char *name, + const void *ns, const struct sysfs_dirent *sd) { if (hash != sd->s_hash) return hash - sd->s_hash; @@ -69,7 +69,7 @@ static int sysfs_name_compare(unsigned int hash, const void *ns, static int sysfs_sd_compare(const struct sysfs_dirent *left, const struct sysfs_dirent *right) { - return sysfs_name_compare(left->s_hash, left->s_ns, left->s_name, + return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns, right); } @@ -132,24 +132,6 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children); } -#ifdef CONFIG_DEBUG_LOCK_ALLOC - -/* Test for attributes that want to ignore lockdep for read-locking */ -static bool ignore_lockdep(struct sysfs_dirent *sd) -{ - return sysfs_type(sd) == SYSFS_KOBJ_ATTR && - sd->s_attr.attr->ignore_lockdep; -} - -#else - -static inline bool ignore_lockdep(struct sysfs_dirent *sd) -{ - return true; -} - -#endif - /** * sysfs_get_active - get an active reference to sysfs_dirent * @sd: sysfs_dirent to get an active reference to @@ -168,7 +150,7 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) if (!atomic_inc_unless_negative(&sd->s_active)) return NULL; - if (likely(!ignore_lockdep(sd))) + if (likely(!sysfs_ignore_lockdep(sd))) rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); return sd; } @@ -187,7 +169,7 @@ void sysfs_put_active(struct sysfs_dirent *sd) if (unlikely(!sd)) return; - if (likely(!ignore_lockdep(sd))) + if (likely(!sysfs_ignore_lockdep(sd))) rwsem_release(&sd->dep_map, 1, _RET_IP_); v = atomic_dec_return(&sd->s_active); if (likely(v != SD_DEACTIVATED_BIAS)) @@ -400,22 +382,19 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) /** * sysfs_addrm_start - prepare for sysfs_dirent add/remove * @acxt: pointer to sysfs_addrm_cxt to be used - * @parent_sd: parent sysfs_dirent * - * This function is called when the caller is about to add or - * remove sysfs_dirent under @parent_sd. This function acquires - * sysfs_mutex. @acxt is used to keep and pass context to - * other addrm functions. + * This function is called when the caller is about to add or remove + * sysfs_dirent. This function acquires sysfs_mutex. @acxt is used + * to keep and pass context to other addrm functions. * * LOCKING: * Kernel thread context (may sleep). sysfs_mutex is locked on * return. */ -void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *parent_sd) +void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt) + __acquires(sysfs_mutex) { memset(acxt, 0, sizeof(*acxt)); - acxt->parent_sd = parent_sd; mutex_lock(&sysfs_mutex); } @@ -424,10 +403,11 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, * __sysfs_add_one - add sysfs_dirent to parent without warning * @acxt: addrm context to use * @sd: sysfs_dirent to be added + * @parent_sd: the parent sysfs_dirent to add @sd to * - * Get @acxt->parent_sd and set sd->s_parent to it and increment - * nlink of parent inode if @sd is a directory and link into the - * children list of the parent. + * Get @parent_sd and set @sd->s_parent to it and increment nlink of + * the parent inode if @sd is a directory and link into the children + * list of the parent. * * This function should be called between calls to * sysfs_addrm_start() and sysfs_addrm_finish() and should be @@ -440,27 +420,28 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, * 0 on success, -EEXIST if entry with the given name already * exists. */ -int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) +int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, + struct sysfs_dirent *parent_sd) { struct sysfs_inode_attrs *ps_iattr; int ret; - if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) { + if (!!sysfs_ns_type(parent_sd) != !!sd->s_ns) { WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", - sysfs_ns_type(acxt->parent_sd) ? "required" : "invalid", - acxt->parent_sd->s_name, sd->s_name); + sysfs_ns_type(parent_sd) ? "required" : "invalid", + parent_sd->s_name, sd->s_name); return -EINVAL; } - sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name); - sd->s_parent = sysfs_get(acxt->parent_sd); + sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); + sd->s_parent = sysfs_get(parent_sd); ret = sysfs_link_sibling(sd); if (ret) return ret; /* Update timestamps on the parent */ - ps_iattr = acxt->parent_sd->s_iattr; + ps_iattr = parent_sd->s_iattr; if (ps_iattr) { struct iattr *ps_iattrs = &ps_iattr->ia_iattr; ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; @@ -490,14 +471,32 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) return path; } +void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name) +{ + char *path; + + path = kzalloc(PATH_MAX, GFP_KERNEL); + if (path) { + sysfs_pathname(parent, path); + strlcat(path, "/", PATH_MAX); + strlcat(path, name, PATH_MAX); + } + + WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n", + path ? path : name); + + kfree(path); +} + /** * sysfs_add_one - add sysfs_dirent to parent * @acxt: addrm context to use * @sd: sysfs_dirent to be added + * @parent_sd: the parent sysfs_dirent to add @sd to * - * Get @acxt->parent_sd and set sd->s_parent to it and increment - * nlink of parent inode if @sd is a directory and link into the - * children list of the parent. + * Get @parent_sd and set @sd->s_parent to it and increment nlink of + * the parent inode if @sd is a directory and link into the children + * list of the parent. * * This function should be called between calls to * sysfs_addrm_start() and sysfs_addrm_finish() and should be @@ -510,23 +509,15 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) * 0 on success, -EEXIST if entry with the given name already * exists. */ -int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) +int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, + struct sysfs_dirent *parent_sd) { int ret; - ret = __sysfs_add_one(acxt, sd); - if (ret == -EEXIST) { - char *path = kzalloc(PATH_MAX, GFP_KERNEL); - WARN(1, KERN_WARNING - "sysfs: cannot create duplicate filename '%s'\n", - (path == NULL) ? sd->s_name - : (sysfs_pathname(acxt->parent_sd, path), - strlcat(path, "/", PATH_MAX), - strlcat(path, sd->s_name, PATH_MAX), - path)); - kfree(path); - } + ret = __sysfs_add_one(acxt, sd, parent_sd); + if (ret == -EEXIST) + sysfs_warn_dup(parent_sd, sd->s_name); return ret; } @@ -545,16 +536,22 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) * LOCKING: * Determined by sysfs_addrm_start(). */ -void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) +static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, + struct sysfs_dirent *sd) { struct sysfs_inode_attrs *ps_iattr; - BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); + /* + * Removal can be called multiple times on the same node. Only the + * first invocation is effective and puts the base ref. + */ + if (sd->s_flags & SYSFS_FLAG_REMOVED) + return; sysfs_unlink_sibling(sd); /* Update timestamps on the parent */ - ps_iattr = acxt->parent_sd->s_iattr; + ps_iattr = sd->s_parent->s_iattr; if (ps_iattr) { struct iattr *ps_iattrs = &ps_iattr->ia_iattr; ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; @@ -577,6 +574,7 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) * sysfs_mutex is released. */ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) + __releases(sysfs_mutex) { /* release resources acquired by sysfs_addrm_start() */ mutex_unlock(&sysfs_mutex); @@ -588,7 +586,7 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) acxt->removed = sd->u.removed_list; sysfs_deactivate(sd); - unmap_bin_file(sd); + sysfs_unmap_bin_file(sd); sysfs_put(sd); } } @@ -597,6 +595,7 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) * sysfs_find_dirent - find sysfs_dirent with the given name * @parent_sd: sysfs_dirent to search under * @name: name to look for + * @ns: the namespace tag to use * * Look for sysfs_dirent with name @name under @parent_sd. * @@ -607,8 +606,8 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) * Pointer to sysfs_dirent if found, NULL if not. */ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, - const void *ns, - const unsigned char *name) + const unsigned char *name, + const void *ns) { struct rb_node *node = parent_sd->s_dir.children.rb_node; unsigned int hash; @@ -620,13 +619,13 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, return NULL; } - hash = sysfs_name_hash(ns, name); + hash = sysfs_name_hash(name, ns); while (node) { struct sysfs_dirent *sd; int result; sd = to_sysfs_dirent(node); - result = sysfs_name_compare(hash, ns, name, sd); + result = sysfs_name_compare(hash, name, ns, sd); if (result < 0) node = node->rb_left; else if (result > 0) @@ -638,9 +637,10 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, } /** - * sysfs_get_dirent - find and get sysfs_dirent with the given name + * sysfs_get_dirent_ns - find and get sysfs_dirent with the given name * @parent_sd: sysfs_dirent to search under * @name: name to look for + * @ns: the namespace tag to use * * Look for sysfs_dirent with name @name under @parent_sd and get * it if found. @@ -651,24 +651,25 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, * RETURNS: * Pointer to sysfs_dirent if found, NULL if not. */ -struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, - const void *ns, - const unsigned char *name) +struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, + const unsigned char *name, + const void *ns) { struct sysfs_dirent *sd; mutex_lock(&sysfs_mutex); - sd = sysfs_find_dirent(parent_sd, ns, name); + sd = sysfs_find_dirent(parent_sd, name, ns); sysfs_get(sd); mutex_unlock(&sysfs_mutex); return sd; } -EXPORT_SYMBOL_GPL(sysfs_get_dirent); +EXPORT_SYMBOL_GPL(sysfs_get_dirent_ns); static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, - enum kobj_ns_type type, const void *ns, const char *name, - struct sysfs_dirent **p_sd) + enum kobj_ns_type type, + const char *name, const void *ns, + struct sysfs_dirent **p_sd) { umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; struct sysfs_addrm_cxt acxt; @@ -685,8 +686,8 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, sd->s_dir.kobj = kobj; /* link in */ - sysfs_addrm_start(&acxt, parent_sd); - rc = sysfs_add_one(&acxt, sd); + sysfs_addrm_start(&acxt); + rc = sysfs_add_one(&acxt, sd, parent_sd); sysfs_addrm_finish(&acxt); if (rc == 0) @@ -701,7 +702,7 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name, struct sysfs_dirent **p_sd) { return create_dir(kobj, kobj->sd, - KOBJ_NS_TYPE_NONE, NULL, name, p_sd); + KOBJ_NS_TYPE_NONE, name, NULL, p_sd); } /** @@ -730,14 +731,14 @@ static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj) } /** - * sysfs_create_dir - create a directory for an object. - * @kobj: object we're creating directory for. + * sysfs_create_dir_ns - create a directory for an object with a namespace tag + * @kobj: object we're creating directory for + * @ns: the namespace tag to use */ -int sysfs_create_dir(struct kobject *kobj) +int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) { enum kobj_ns_type type; struct sysfs_dirent *parent_sd, *sd; - const void *ns = NULL; int error = 0; BUG_ON(!kobj); @@ -750,11 +751,9 @@ int sysfs_create_dir(struct kobject *kobj) if (!parent_sd) return -ENOENT; - if (sysfs_ns_type(parent_sd)) - ns = kobj->ktype->namespace(kobj); type = sysfs_read_ns_type(kobj); - error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd); + error = create_dir(kobj, parent_sd, type, kobject_name(kobj), ns, &sd); if (!error) kobj->sd = sd; return error; @@ -776,7 +775,7 @@ static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry, type = sysfs_ns_type(parent_sd); ns = sysfs_info(dir->i_sb)->ns[type]; - sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name); + sd = sysfs_find_dirent(parent_sd, dentry->d_name.name, ns); /* no such entry */ if (!sd) { @@ -807,41 +806,128 @@ const struct inode_operations sysfs_dir_inode_operations = { .setxattr = sysfs_setxattr, }; -static void remove_dir(struct sysfs_dirent *sd) +static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos) { - struct sysfs_addrm_cxt acxt; + struct sysfs_dirent *last; - sysfs_addrm_start(&acxt, sd->s_parent); - sysfs_remove_one(&acxt, sd); - sysfs_addrm_finish(&acxt); + while (true) { + struct rb_node *rbn; + + last = pos; + + if (sysfs_type(pos) != SYSFS_DIR) + break; + + rbn = rb_first(&pos->s_dir.children); + if (!rbn) + break; + + pos = to_sysfs_dirent(rbn); + } + + return last; } -void sysfs_remove_subdir(struct sysfs_dirent *sd) +/** + * sysfs_next_descendant_post - find the next descendant for post-order walk + * @pos: the current position (%NULL to initiate traversal) + * @root: sysfs_dirent whose descendants to walk + * + * Find the next descendant to visit for post-order traversal of @root's + * descendants. @root is included in the iteration and the last node to be + * visited. + */ +static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos, + struct sysfs_dirent *root) { - remove_dir(sd); + struct rb_node *rbn; + + lockdep_assert_held(&sysfs_mutex); + + /* if first iteration, visit leftmost descendant which may be root */ + if (!pos) + return sysfs_leftmost_descendant(root); + + /* if we visited @root, we're done */ + if (pos == root) + return NULL; + + /* if there's an unvisited sibling, visit its leftmost descendant */ + rbn = rb_next(&pos->s_rb); + if (rbn) + return sysfs_leftmost_descendant(to_sysfs_dirent(rbn)); + + /* no sibling left, visit parent */ + return pos->s_parent; } +static void __sysfs_remove(struct sysfs_addrm_cxt *acxt, + struct sysfs_dirent *sd) +{ + struct sysfs_dirent *pos, *next; + + if (!sd) + return; -static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) + pr_debug("sysfs %s: removing\n", sd->s_name); + + next = NULL; + do { + pos = next; + next = sysfs_next_descendant_post(pos, sd); + if (pos) + sysfs_remove_one(acxt, pos); + } while (next); +} + +/** + * sysfs_remove - remove a sysfs_dirent recursively + * @sd: the sysfs_dirent to remove + * + * Remove @sd along with all its subdirectories and files. + */ +void sysfs_remove(struct sysfs_dirent *sd) { struct sysfs_addrm_cxt acxt; - struct rb_node *pos; - if (!dir_sd) - return; + sysfs_addrm_start(&acxt); + __sysfs_remove(&acxt, sd); + sysfs_addrm_finish(&acxt); +} - pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); - sysfs_addrm_start(&acxt, dir_sd); - pos = rb_first(&dir_sd->s_dir.children); - while (pos) { - struct sysfs_dirent *sd = to_sysfs_dirent(pos); - pos = rb_next(pos); - if (sysfs_type(sd) != SYSFS_DIR) - sysfs_remove_one(&acxt, sd); +/** + * sysfs_hash_and_remove - find a sysfs_dirent by name and remove it + * @dir_sd: parent of the target + * @name: name of the sysfs_dirent to remove + * @ns: namespace tag of the sysfs_dirent to remove + * + * Look for the sysfs_dirent with @name and @ns under @dir_sd and remove + * it. Returns 0 on success, -ENOENT if such entry doesn't exist. + */ +int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, + const void *ns) +{ + struct sysfs_addrm_cxt acxt; + struct sysfs_dirent *sd; + + if (!dir_sd) { + WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n", + name); + return -ENOENT; } + + sysfs_addrm_start(&acxt); + + sd = sysfs_find_dirent(dir_sd, name, ns); + if (sd) + __sysfs_remove(&acxt, sd); + sysfs_addrm_finish(&acxt); - remove_dir(dir_sd); + if (sd) + return 0; + else + return -ENOENT; } /** @@ -852,21 +938,34 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) * 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 sysfs_dirent *sd = kobj->sd; - spin_lock(&sysfs_assoc_lock); + /* + * In general, kboject owner is responsible for ensuring removal + * doesn't race with other operations and sysfs doesn't provide any + * protection; however, when @kobj is used as a symlink target, the + * symlinking entity usually doesn't own @kobj and thus has no + * control over removal. @kobj->sd may be removed anytime and + * symlink code may end up dereferencing an already freed sd. + * + * sysfs_symlink_target_lock synchronizes @kobj->sd disassociation + * against symlink operations so that symlink code can safely + * dereference @kobj->sd. + */ + spin_lock(&sysfs_symlink_target_lock); kobj->sd = NULL; - spin_unlock(&sysfs_assoc_lock); + spin_unlock(&sysfs_symlink_target_lock); - __sysfs_remove_dir(sd); + if (sd) { + WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR); + sysfs_remove(sd); + } } -int sysfs_rename(struct sysfs_dirent *sd, - struct sysfs_dirent *new_parent_sd, const void *new_ns, - const char *new_name) +int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd, + const char *new_name, const void *new_ns) { int error; @@ -878,7 +977,7 @@ int sysfs_rename(struct sysfs_dirent *sd, goto out; /* nothing to rename */ error = -EEXIST; - if (sysfs_find_dirent(new_parent_sd, new_ns, new_name)) + if (sysfs_find_dirent(new_parent_sd, new_name, new_ns)) goto out; /* rename sysfs_dirent */ @@ -899,7 +998,7 @@ int sysfs_rename(struct sysfs_dirent *sd, sysfs_get(new_parent_sd); sysfs_put(sd->s_parent); sd->s_ns = new_ns; - sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name); + sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); sd->s_parent = new_parent_sd; sysfs_link_sibling(sd); @@ -909,30 +1008,25 @@ int sysfs_rename(struct sysfs_dirent *sd, return error; } -int sysfs_rename_dir(struct kobject *kobj, const char *new_name) +int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, + const void *new_ns) { struct sysfs_dirent *parent_sd = kobj->sd->s_parent; - const void *new_ns = NULL; - - if (sysfs_ns_type(parent_sd)) - new_ns = kobj->ktype->namespace(kobj); - return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name); + return sysfs_rename(kobj->sd, parent_sd, new_name, new_ns); } -int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) +int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, + const void *new_ns) { struct sysfs_dirent *sd = kobj->sd; struct sysfs_dirent *new_parent_sd; - const void *new_ns = NULL; BUG_ON(!sd->s_parent); - if (sysfs_ns_type(sd->s_parent)) - new_ns = kobj->ktype->namespace(kobj); new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root; - return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name); + return sysfs_rename(sd, new_parent_sd, sd->s_name, new_ns); } /* Relationship between s_mode and the DT_xxx types */ diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 15ef5eb..79b5da2 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -21,70 +21,114 @@ #include <linux/mutex.h> #include <linux/limits.h> #include <linux/uaccess.h> +#include <linux/seq_file.h> +#include <linux/mm.h> #include "sysfs.h" /* - * There's one sysfs_buffer for each open file and one - * sysfs_open_dirent for each sysfs_dirent with one or more open - * files. + * There's one sysfs_open_file for each open file and one sysfs_open_dirent + * for each sysfs_dirent with one or more open files. * - * filp->private_data points to sysfs_buffer and - * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open - * is protected by sysfs_open_dirent_lock. + * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is + * protected by sysfs_open_dirent_lock. + * + * filp->private_data points to seq_file whose ->private points to + * sysfs_open_file. sysfs_open_files are chained at + * sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex. */ static DEFINE_SPINLOCK(sysfs_open_dirent_lock); +static DEFINE_MUTEX(sysfs_open_file_mutex); struct sysfs_open_dirent { atomic_t refcnt; atomic_t event; wait_queue_head_t poll; - struct list_head buffers; /* goes through sysfs_buffer.list */ + struct list_head files; /* goes through sysfs_open_file.list */ }; -struct sysfs_buffer { - size_t count; - loff_t pos; - char *page; - const struct sysfs_ops *ops; +struct sysfs_open_file { + struct sysfs_dirent *sd; + struct file *file; struct mutex mutex; - int needs_read_fill; int event; struct list_head list; + + bool mmapped; + const struct vm_operations_struct *vm_ops; }; -/** - * fill_read_buffer - allocate and fill buffer from object. - * @dentry: dentry pointer. - * @buffer: data buffer for file. - * - * 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 unless an error - * is returned. +static bool sysfs_is_bin(struct sysfs_dirent *sd) +{ + return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR; +} + +static struct sysfs_open_file *sysfs_of(struct file *file) +{ + return ((struct seq_file *)file->private_data)->private; +} + +/* + * Determine ktype->sysfs_ops for the given sysfs_dirent. This function + * must be called while holding an active reference. */ -static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer) +static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) { - struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - const struct sysfs_ops *ops = buffer->ops; - int ret = 0; + struct kobject *kobj = sd->s_parent->s_dir.kobj; + + if (!sysfs_ignore_lockdep(sd)) + lockdep_assert_held(sd); + return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; +} + +/* + * Reads on sysfs are handled through seq_file, which takes care of hairy + * details like buffering and seeking. The following function pipes + * sysfs_ops->show() result through seq_file. + */ +static int sysfs_seq_show(struct seq_file *sf, void *v) +{ + struct sysfs_open_file *of = sf->private; + struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + const struct sysfs_ops *ops; + char *buf; ssize_t count; - if (!buffer->page) - buffer->page = (char *) get_zeroed_page(GFP_KERNEL); - if (!buffer->page) - return -ENOMEM; + /* acquire buffer and ensure that it's >= PAGE_SIZE */ + count = seq_get_buf(sf, &buf); + if (count < PAGE_SIZE) { + seq_commit(sf, -1); + return 0; + } - /* need attr_sd for attr and ops, its parent for kobj */ - if (!sysfs_get_active(attr_sd)) + /* + * Need @of->sd for attr and ops, its parent for kobj. @of->mutex + * nests outside active ref and is just to ensure that the ops + * aren't called concurrently for the same open file. + */ + mutex_lock(&of->mutex); + if (!sysfs_get_active(of->sd)) { + mutex_unlock(&of->mutex); return -ENODEV; + } - buffer->event = atomic_read(&attr_sd->s_attr.open->event); - count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page); + of->event = atomic_read(&of->sd->s_attr.open->event); - sysfs_put_active(attr_sd); + /* + * Lookup @ops and invoke show(). Control may reach here via seq + * file lseek even if @ops->show() isn't implemented. + */ + ops = sysfs_file_ops(of->sd); + if (ops->show) + count = ops->show(kobj, of->sd->s_attr.attr, buf); + else + count = 0; + + sysfs_put_active(of->sd); + mutex_unlock(&of->mutex); + + if (count < 0) + return count; /* * The code works fine with PAGE_SIZE return but it's likely to @@ -96,155 +140,389 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer) /* Try to struggle along */ count = PAGE_SIZE - 1; } - if (count >= 0) { - buffer->needs_read_fill = 0; - buffer->count = count; - } else { - ret = count; - } - return ret; + seq_commit(sf, count); + return 0; } -/** - * sysfs_read_file - read an attribute. - * @file: file pointer. - * @buf: buffer to fill. - * @count: number of bytes to read. - * @ppos: starting offset in file. - * - * Userspace wants to read an attribute file. The attribute descriptor - * is in the file's ->d_fsdata. The target object is in the directory's - * ->d_fsdata. - * - * We call fill_read_buffer() to allocate and fill the buffer from the - * object's show() method exactly once (if the read is happening from - * the beginning of the file). That should fill the entire buffer with - * all the data the object has to offer for that attribute. - * We then call flush_read_buffer() to copy the buffer to userspace - * in the increments specified. +/* + * Read method for bin files. As reading a bin file can have side-effects, + * the exact offset and bytes specified in read(2) call should be passed to + * the read callback making it difficult to use seq_file. Implement + * simplistic custom buffering for bin files. */ - -static ssize_t -sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) +static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf, + size_t bytes, loff_t *off) { - struct sysfs_buffer *buffer = file->private_data; - ssize_t retval = 0; + struct sysfs_open_file *of = sysfs_of(file); + struct bin_attribute *battr = of->sd->s_attr.bin_attr; + struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + loff_t size = file_inode(file)->i_size; + int count = min_t(size_t, bytes, PAGE_SIZE); + loff_t offs = *off; + char *buf; + + if (!bytes) + return 0; - mutex_lock(&buffer->mutex); - if (buffer->needs_read_fill || *ppos == 0) { - retval = fill_read_buffer(file->f_path.dentry, buffer); - if (retval) - goto out; + if (size) { + if (offs > size) + return 0; + if (offs + count > size) + count = size - offs; } - pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", - __func__, count, *ppos, buffer->page); - retval = simple_read_from_buffer(buf, count, ppos, buffer->page, - buffer->count); -out: - mutex_unlock(&buffer->mutex); - return retval; -} -/** - * fill_write_buffer - copy buffer from userspace. - * @buffer: data buffer for file. - * @buf: data from user. - * @count: number of bytes in @userbuf. - * - * Allocate @buffer->page if it hasn't been already, then - * copy the user-supplied buffer into it. - */ -static int fill_write_buffer(struct sysfs_buffer *buffer, - const char __user *buf, size_t count) -{ - int error; - - if (!buffer->page) - buffer->page = (char *)get_zeroed_page(GFP_KERNEL); - if (!buffer->page) + buf = kmalloc(count, GFP_KERNEL); + if (!buf) return -ENOMEM; - if (count >= PAGE_SIZE) - count = PAGE_SIZE - 1; - error = copy_from_user(buffer->page, buf, count); - buffer->needs_read_fill = 1; - /* if buf is assumed to contain a string, terminate it by \0, - so e.g. sscanf() can scan the string easily */ - buffer->page[count] = 0; - return error ? -EFAULT : count; -} + /* need of->sd for battr, its parent for kobj */ + mutex_lock(&of->mutex); + if (!sysfs_get_active(of->sd)) { + count = -ENODEV; + mutex_unlock(&of->mutex); + goto out_free; + } + + if (battr->read) + count = battr->read(file, kobj, battr, buf, offs, count); + else + count = -EIO; + sysfs_put_active(of->sd); + mutex_unlock(&of->mutex); + + if (count < 0) + goto out_free; + + if (copy_to_user(userbuf, buf, count)) { + count = -EFAULT; + goto out_free; + } + + pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); + + *off = offs + count; + + out_free: + kfree(buf); + return count; +} /** - * flush_write_buffer - push buffer to kobject. - * @dentry: dentry to the attribute - * @buffer: data buffer for file. - * @count: number of bytes + * flush_write_buffer - push buffer to kobject + * @of: open file + * @buf: data buffer for file + * @off: file offset to write to + * @count: number of bytes * - * Get the correct pointers for the kobject 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(). + * Get the correct pointers for the kobject and the attribute we're dealing + * with, then call the store() method for it with @buf. */ -static int flush_write_buffer(struct dentry *dentry, - struct sysfs_buffer *buffer, size_t count) +static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, + size_t count) { - struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - const struct sysfs_ops *ops = buffer->ops; - int rc; + struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + int rc = 0; - /* need attr_sd for attr and ops, its parent for kobj */ - if (!sysfs_get_active(attr_sd)) + /* + * Need @of->sd for attr and ops, its parent for kobj. @of->mutex + * nests outside active ref and is just to ensure that the ops + * aren't called concurrently for the same open file. + */ + mutex_lock(&of->mutex); + if (!sysfs_get_active(of->sd)) { + mutex_unlock(&of->mutex); return -ENODEV; + } - rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count); + if (sysfs_is_bin(of->sd)) { + struct bin_attribute *battr = of->sd->s_attr.bin_attr; - sysfs_put_active(attr_sd); + rc = -EIO; + if (battr->write) + rc = battr->write(of->file, kobj, battr, buf, off, + count); + } else { + const struct sysfs_ops *ops = sysfs_file_ops(of->sd); + + rc = ops->store(kobj, of->sd->s_attr.attr, buf, count); + } + + sysfs_put_active(of->sd); + mutex_unlock(&of->mutex); return rc; } - /** - * sysfs_write_file - write an attribute. - * @file: file pointer - * @buf: data to write - * @count: number of bytes - * @ppos: starting offset + * sysfs_write_file - write an attribute + * @file: file pointer + * @user_buf: data to write + * @count: number of bytes + * @ppos: starting offset + * + * Copy data in from userland and pass it to the matching + * sysfs_ops->store() by invoking flush_write_buffer(). * - * Similar to sysfs_read_file(), though working in the opposite direction. - * We allocate and fill the data from the user in fill_write_buffer(), - * then push it to the kobject in flush_write_buffer(). - * There is no easy way for us to know if userspace is only doing a partial - * write, so we don't support them. We expect the entire buffer to come - * on the first write. - * Hint: if you're writing a value, first read the file, modify only the - * the value you're changing, then write entire buffer back. + * There is no easy way for us to know if userspace is only doing a partial + * write, so we don't support them. We expect the entire buffer to come on + * the first write. Hint: if you're writing a value, first read the file, + * modify only the the value you're changing, then write entire buffer + * back. */ -static ssize_t sysfs_write_file(struct file *file, const char __user *buf, +static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) { - struct sysfs_buffer *buffer = file->private_data; - ssize_t len; + struct sysfs_open_file *of = sysfs_of(file); + ssize_t len = min_t(size_t, count, PAGE_SIZE); + loff_t size = file_inode(file)->i_size; + char *buf; + + if (sysfs_is_bin(of->sd) && size) { + if (size <= *ppos) + return 0; + len = min_t(ssize_t, len, size - *ppos); + } - mutex_lock(&buffer->mutex); - len = fill_write_buffer(buffer, buf, count); - if (len > 0) - len = flush_write_buffer(file->f_path.dentry, buffer, len); + if (!len) + return 0; + + buf = kmalloc(len + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (copy_from_user(buf, user_buf, len)) { + len = -EFAULT; + goto out_free; + } + buf[len] = '\0'; /* guarantee string termination */ + + len = flush_write_buffer(of, buf, *ppos, len); if (len > 0) *ppos += len; - mutex_unlock(&buffer->mutex); +out_free: + kfree(buf); return len; } +static void sysfs_bin_vma_open(struct vm_area_struct *vma) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + + if (!of->vm_ops) + return; + + if (!sysfs_get_active(of->sd)) + return; + + if (of->vm_ops->open) + of->vm_ops->open(vma); + + sysfs_put_active(of->sd); +} + +static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + int ret; + + if (!of->vm_ops) + return VM_FAULT_SIGBUS; + + if (!sysfs_get_active(of->sd)) + return VM_FAULT_SIGBUS; + + ret = VM_FAULT_SIGBUS; + if (of->vm_ops->fault) + ret = of->vm_ops->fault(vma, vmf); + + sysfs_put_active(of->sd); + return ret; +} + +static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + int ret; + + if (!of->vm_ops) + return VM_FAULT_SIGBUS; + + if (!sysfs_get_active(of->sd)) + return VM_FAULT_SIGBUS; + + ret = 0; + if (of->vm_ops->page_mkwrite) + ret = of->vm_ops->page_mkwrite(vma, vmf); + else + file_update_time(file); + + sysfs_put_active(of->sd); + return ret; +} + +static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + int ret; + + if (!of->vm_ops) + return -EINVAL; + + if (!sysfs_get_active(of->sd)) + return -EINVAL; + + ret = -EINVAL; + if (of->vm_ops->access) + ret = of->vm_ops->access(vma, addr, buf, len, write); + + sysfs_put_active(of->sd); + return ret; +} + +#ifdef CONFIG_NUMA +static int sysfs_bin_set_policy(struct vm_area_struct *vma, + struct mempolicy *new) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + int ret; + + if (!of->vm_ops) + return 0; + + if (!sysfs_get_active(of->sd)) + return -EINVAL; + + ret = 0; + if (of->vm_ops->set_policy) + ret = of->vm_ops->set_policy(vma, new); + + sysfs_put_active(of->sd); + return ret; +} + +static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma, + unsigned long addr) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + struct mempolicy *pol; + + if (!of->vm_ops) + return vma->vm_policy; + + if (!sysfs_get_active(of->sd)) + return vma->vm_policy; + + pol = vma->vm_policy; + if (of->vm_ops->get_policy) + pol = of->vm_ops->get_policy(vma, addr); + + sysfs_put_active(of->sd); + return pol; +} + +static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, + const nodemask_t *to, unsigned long flags) +{ + struct file *file = vma->vm_file; + struct sysfs_open_file *of = sysfs_of(file); + int ret; + + if (!of->vm_ops) + return 0; + + if (!sysfs_get_active(of->sd)) + return 0; + + ret = 0; + if (of->vm_ops->migrate) + ret = of->vm_ops->migrate(vma, from, to, flags); + + sysfs_put_active(of->sd); + return ret; +} +#endif + +static const struct vm_operations_struct sysfs_bin_vm_ops = { + .open = sysfs_bin_vma_open, + .fault = sysfs_bin_fault, + .page_mkwrite = sysfs_bin_page_mkwrite, + .access = sysfs_bin_access, +#ifdef CONFIG_NUMA + .set_policy = sysfs_bin_set_policy, + .get_policy = sysfs_bin_get_policy, + .migrate = sysfs_bin_migrate, +#endif +}; + +static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct sysfs_open_file *of = sysfs_of(file); + struct bin_attribute *battr = of->sd->s_attr.bin_attr; + struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + int rc; + + mutex_lock(&of->mutex); + + /* need of->sd for battr, its parent for kobj */ + rc = -ENODEV; + if (!sysfs_get_active(of->sd)) + goto out_unlock; + + if (!battr->mmap) + goto out_put; + + rc = battr->mmap(file, kobj, battr, vma); + if (rc) + goto out_put; + + /* + * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() + * to satisfy versions of X which crash if the mmap fails: that + * substitutes a new vm_file, and we don't then want bin_vm_ops. + */ + if (vma->vm_file != file) + goto out_put; + + rc = -EINVAL; + if (of->mmapped && of->vm_ops != vma->vm_ops) + goto out_put; + + /* + * It is not possible to successfully wrap close. + * So error if someone is trying to use close. + */ + rc = -EINVAL; + if (vma->vm_ops && vma->vm_ops->close) + goto out_put; + + rc = 0; + of->mmapped = 1; + of->vm_ops = vma->vm_ops; + vma->vm_ops = &sysfs_bin_vm_ops; +out_put: + sysfs_put_active(of->sd); +out_unlock: + mutex_unlock(&of->mutex); + + return rc; +} + /** * sysfs_get_open_dirent - get or create sysfs_open_dirent * @sd: target sysfs_dirent - * @buffer: sysfs_buffer for this instance of open + * @of: sysfs_open_file for this instance of open * * If @sd->s_attr.open exists, increment its reference count; - * otherwise, create one. @buffer is chained to the buffers - * list. + * otherwise, create one. @of is chained to the files list. * * LOCKING: * Kernel thread context (may sleep). @@ -253,11 +531,12 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf, * 0 on success, -errno on failure. */ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, - struct sysfs_buffer *buffer) + struct sysfs_open_file *of) { struct sysfs_open_dirent *od, *new_od = NULL; retry: + mutex_lock(&sysfs_open_file_mutex); spin_lock_irq(&sysfs_open_dirent_lock); if (!sd->s_attr.open && new_od) { @@ -268,10 +547,11 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, od = sd->s_attr.open; if (od) { atomic_inc(&od->refcnt); - list_add_tail(&buffer->list, &od->buffers); + list_add_tail(&of->list, &od->files); } spin_unlock_irq(&sysfs_open_dirent_lock); + mutex_unlock(&sysfs_open_file_mutex); if (od) { kfree(new_od); @@ -286,36 +566,40 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, atomic_set(&new_od->refcnt, 0); atomic_set(&new_od->event, 1); init_waitqueue_head(&new_od->poll); - INIT_LIST_HEAD(&new_od->buffers); + INIT_LIST_HEAD(&new_od->files); goto retry; } /** * sysfs_put_open_dirent - put sysfs_open_dirent * @sd: target sysfs_dirent - * @buffer: associated sysfs_buffer + * @of: associated sysfs_open_file * - * Put @sd->s_attr.open and unlink @buffer from the buffers list. - * If reference count reaches zero, disassociate and free it. + * Put @sd->s_attr.open and unlink @of from the files list. If + * reference count reaches zero, disassociate and free it. * * LOCKING: * None. */ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, - struct sysfs_buffer *buffer) + struct sysfs_open_file *of) { struct sysfs_open_dirent *od = sd->s_attr.open; unsigned long flags; + mutex_lock(&sysfs_open_file_mutex); spin_lock_irqsave(&sysfs_open_dirent_lock, flags); - list_del(&buffer->list); + if (of) + list_del(&of->list); + if (atomic_dec_and_test(&od->refcnt)) sd->s_attr.open = NULL; else od = NULL; spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); + mutex_unlock(&sysfs_open_file_mutex); kfree(od); } @@ -324,67 +608,81 @@ static int sysfs_open_file(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; - struct sysfs_buffer *buffer; - const struct sysfs_ops *ops; + struct sysfs_open_file *of; + bool has_read, has_write; int error = -EACCES; /* need attr_sd for attr and ops, its parent for kobj */ if (!sysfs_get_active(attr_sd)) return -ENODEV; - /* every kobject with an attribute needs a ktype assigned */ - if (kobj->ktype && kobj->ktype->sysfs_ops) - ops = kobj->ktype->sysfs_ops; - else { - WARN(1, KERN_ERR - "missing sysfs attribute operations for kobject: %s\n", - kobject_name(kobj)); - goto err_out; - } + if (sysfs_is_bin(attr_sd)) { + struct bin_attribute *battr = attr_sd->s_attr.bin_attr; - /* File needs write support. - * The inode's perms must say it's ok, - * and we must have a store method. - */ - if (file->f_mode & FMODE_WRITE) { - if (!(inode->i_mode & S_IWUGO) || !ops->store) - goto err_out; - } + has_read = battr->read || battr->mmap; + has_write = battr->write || battr->mmap; + } else { + const struct sysfs_ops *ops = sysfs_file_ops(attr_sd); - /* File needs read support. - * The inode's perms must say it's ok, and we there - * must be a show method for it. - */ - if (file->f_mode & FMODE_READ) { - if (!(inode->i_mode & S_IRUGO) || !ops->show) + /* every kobject with an attribute needs a ktype assigned */ + if (WARN(!ops, KERN_ERR + "missing sysfs attribute operations for kobject: %s\n", + kobject_name(kobj))) goto err_out; + + has_read = ops->show; + has_write = ops->store; } - /* No error? Great, allocate a buffer for the file, and store it - * it in file->private_data for easy access. - */ + /* check perms and supported operations */ + if ((file->f_mode & FMODE_WRITE) && + (!(inode->i_mode & S_IWUGO) || !has_write)) + goto err_out; + + if ((file->f_mode & FMODE_READ) && + (!(inode->i_mode & S_IRUGO) || !has_read)) + goto err_out; + + /* allocate a sysfs_open_file for the file */ error = -ENOMEM; - buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL); - if (!buffer) + of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL); + if (!of) goto err_out; - mutex_init(&buffer->mutex); - buffer->needs_read_fill = 1; - buffer->ops = ops; - file->private_data = buffer; + mutex_init(&of->mutex); + of->sd = attr_sd; + of->file = file; - /* make sure we have open dirent struct */ - error = sysfs_get_open_dirent(attr_sd, buffer); + /* + * Always instantiate seq_file even if read access doesn't use + * seq_file or is not requested. This unifies private data access + * and readable regular files are the vast majority anyway. + */ + if (sysfs_is_bin(attr_sd)) + error = single_open(file, NULL, of); + else + error = single_open(file, sysfs_seq_show, of); if (error) goto err_free; + /* seq_file clears PWRITE unconditionally, restore it if WRITE */ + if (file->f_mode & FMODE_WRITE) + file->f_mode |= FMODE_PWRITE; + + /* make sure we have open dirent struct */ + error = sysfs_get_open_dirent(attr_sd, of); + if (error) + goto err_close; + /* open succeeded, put active references */ sysfs_put_active(attr_sd); return 0; - err_free: - kfree(buffer); - err_out: +err_close: + single_release(inode, file); +err_free: + kfree(of); +err_out: sysfs_put_active(attr_sd); return error; } @@ -392,17 +690,41 @@ static int sysfs_open_file(struct inode *inode, struct file *file) static int sysfs_release(struct inode *inode, struct file *filp) { struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; - struct sysfs_buffer *buffer = filp->private_data; + struct sysfs_open_file *of = sysfs_of(filp); - sysfs_put_open_dirent(sd, buffer); - - if (buffer->page) - free_page((unsigned long)buffer->page); - kfree(buffer); + sysfs_put_open_dirent(sd, of); + single_release(inode, filp); + kfree(of); return 0; } +void sysfs_unmap_bin_file(struct sysfs_dirent *sd) +{ + struct sysfs_open_dirent *od; + struct sysfs_open_file *of; + + if (!sysfs_is_bin(sd)) + return; + + spin_lock_irq(&sysfs_open_dirent_lock); + od = sd->s_attr.open; + if (od) + atomic_inc(&od->refcnt); + spin_unlock_irq(&sysfs_open_dirent_lock); + if (!od) + return; + + mutex_lock(&sysfs_open_file_mutex); + list_for_each_entry(of, &od->files, list) { + struct inode *inode = file_inode(of->file); + unmap_mapping_range(inode->i_mapping, 0, 0, 1); + } + mutex_unlock(&sysfs_open_file_mutex); + + sysfs_put_open_dirent(sd, NULL); +} + /* Sysfs attribute files are pollable. The idea is that you read * the content and then you use 'poll' or 'select' to wait for * the content to change. When the content changes (assuming the @@ -418,7 +740,7 @@ static int sysfs_release(struct inode *inode, struct file *filp) */ static unsigned int sysfs_poll(struct file *filp, poll_table *wait) { - struct sysfs_buffer *buffer = filp->private_data; + struct sysfs_open_file *of = sysfs_of(filp); struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; struct sysfs_open_dirent *od = attr_sd->s_attr.open; @@ -430,13 +752,12 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait) sysfs_put_active(attr_sd); - if (buffer->event != atomic_read(&od->event)) + if (of->event != atomic_read(&od->event)) goto trigger; return DEFAULT_POLLMASK; trigger: - buffer->needs_read_fill = 1; return DEFAULT_POLLMASK|POLLERR|POLLPRI; } @@ -466,9 +787,9 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) mutex_lock(&sysfs_mutex); if (sd && dir) - sd = sysfs_find_dirent(sd, NULL, dir); + sd = sysfs_find_dirent(sd, dir, NULL); if (sd && attr) - sd = sysfs_find_dirent(sd, NULL, attr); + sd = sysfs_find_dirent(sd, attr, NULL); if (sd) sysfs_notify_dirent(sd); @@ -477,7 +798,7 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) EXPORT_SYMBOL_GPL(sysfs_notify); const struct file_operations sysfs_file_operations = { - .read = sysfs_read_file, + .read = seq_read, .write = sysfs_write_file, .llseek = generic_file_llseek, .open = sysfs_open_file, @@ -485,58 +806,25 @@ const struct file_operations sysfs_file_operations = { .poll = sysfs_poll, }; -static int sysfs_attr_ns(struct kobject *kobj, const struct attribute *attr, - const void **pns) -{ - struct sysfs_dirent *dir_sd = kobj->sd; - const struct sysfs_ops *ops; - const void *ns = NULL; - int err; - - if (!dir_sd) { - WARN(1, KERN_ERR "sysfs: kobject %s without dirent\n", - kobject_name(kobj)); - return -ENOENT; - } - - err = 0; - if (!sysfs_ns_type(dir_sd)) - goto out; - - err = -EINVAL; - if (!kobj->ktype) - goto out; - ops = kobj->ktype->sysfs_ops; - if (!ops) - goto out; - if (!ops->namespace) - goto out; - - err = 0; - ns = ops->namespace(kobj, attr); -out: - if (err) { - WARN(1, KERN_ERR - "missing sysfs namespace attribute operation for kobject: %s\n", - kobject_name(kobj)); - } - *pns = ns; - return err; -} +const struct file_operations sysfs_bin_operations = { + .read = sysfs_bin_read, + .write = sysfs_write_file, + .llseek = generic_file_llseek, + .mmap = sysfs_bin_mmap, + .open = sysfs_open_file, + .release = sysfs_release, + .poll = sysfs_poll, +}; -int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, - const struct attribute *attr, int type, umode_t amode) +int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, + umode_t amode, const void *ns) { umode_t mode = (amode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; - const void *ns; int rc; - rc = sysfs_attr_ns(dir_sd->s_dir.kobj, attr, &ns); - if (rc) - return rc; - sd = sysfs_new_dirent(attr->name, mode, type); if (!sd) return -ENOMEM; @@ -545,8 +833,8 @@ int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, sd->s_attr.attr = (void *)attr; sysfs_dirent_init_lockdep(sd); - sysfs_addrm_start(&acxt, dir_sd); - rc = sysfs_add_one(&acxt, sd); + sysfs_addrm_start(&acxt); + rc = sysfs_add_one(&acxt, sd, dir_sd); sysfs_addrm_finish(&acxt); if (rc) @@ -559,23 +847,25 @@ int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, int type) { - return sysfs_add_file_mode(dir_sd, attr, type, attr->mode); + return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL); } - /** - * sysfs_create_file - create an attribute file for an object. - * @kobj: object we're creating for. - * @attr: attribute descriptor. + * sysfs_create_file_ns - create an attribute file for an object with custom ns + * @kobj: object we're creating for + * @attr: attribute descriptor + * @ns: namespace the new file should belong to */ -int sysfs_create_file(struct kobject *kobj, const struct attribute *attr) +int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, + const void *ns) { BUG_ON(!kobj || !kobj->sd || !attr); - return sysfs_add_file(kobj->sd, attr, SYSFS_KOBJ_ATTR); + return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR, + attr->mode, ns); } -EXPORT_SYMBOL_GPL(sysfs_create_file); +EXPORT_SYMBOL_GPL(sysfs_create_file_ns); int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr) { @@ -604,7 +894,7 @@ int sysfs_add_file_to_group(struct kobject *kobj, int error; if (group) - dir_sd = sysfs_get_dirent(kobj->sd, NULL, group); + dir_sd = sysfs_get_dirent(kobj->sd, group); else dir_sd = sysfs_get(kobj->sd); @@ -630,17 +920,12 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, { struct sysfs_dirent *sd; struct iattr newattrs; - const void *ns; int rc; - rc = sysfs_attr_ns(kobj, attr, &ns); - if (rc) - return rc; - mutex_lock(&sysfs_mutex); rc = -ENOENT; - sd = sysfs_find_dirent(kobj->sd, ns, attr->name); + sd = sysfs_find_dirent(kobj->sd, attr->name, NULL); if (!sd) goto out; @@ -655,22 +940,21 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, EXPORT_SYMBOL_GPL(sysfs_chmod_file); /** - * sysfs_remove_file - remove an object attribute. - * @kobj: object we're acting for. - * @attr: attribute descriptor. + * sysfs_remove_file_ns - remove an object attribute with a custom ns tag + * @kobj: object we're acting for + * @attr: attribute descriptor + * @ns: namespace tag of the file to remove * - * Hash the attribute name and kill the victim. + * Hash the attribute name and namespace tag and kill the victim. */ -void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) +void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, + const void *ns) { - const void *ns; - - if (sysfs_attr_ns(kobj, attr, &ns)) - return; + struct sysfs_dirent *dir_sd = kobj->sd; - sysfs_hash_and_remove(kobj->sd, ns, attr->name); + sysfs_hash_and_remove(dir_sd, attr->name, ns); } -EXPORT_SYMBOL_GPL(sysfs_remove_file); +EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr) { @@ -692,16 +976,42 @@ void sysfs_remove_file_from_group(struct kobject *kobj, struct sysfs_dirent *dir_sd; if (group) - dir_sd = sysfs_get_dirent(kobj->sd, NULL, group); + dir_sd = sysfs_get_dirent(kobj->sd, group); else dir_sd = sysfs_get(kobj->sd); if (dir_sd) { - sysfs_hash_and_remove(dir_sd, NULL, attr->name); + sysfs_hash_and_remove(dir_sd, attr->name, NULL); sysfs_put(dir_sd); } } EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); +/** + * sysfs_create_bin_file - create binary file for object. + * @kobj: object. + * @attr: attribute descriptor. + */ +int sysfs_create_bin_file(struct kobject *kobj, + const struct bin_attribute *attr) +{ + BUG_ON(!kobj || !kobj->sd || !attr); + + return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); +} +EXPORT_SYMBOL_GPL(sysfs_create_bin_file); + +/** + * sysfs_remove_bin_file - remove binary file for object. + * @kobj: object. + * @attr: attribute descriptor. + */ +void sysfs_remove_bin_file(struct kobject *kobj, + const struct bin_attribute *attr) +{ + sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL); +} +EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); + struct sysfs_schedule_callback_struct { struct list_head workq_list; struct kobject *kobj; diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 5f92cd2..1898a10 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -26,7 +26,7 @@ static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, if (grp->attrs) for (attr = grp->attrs; *attr; attr++) - sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name); + sysfs_hash_and_remove(dir_sd, (*attr)->name, NULL); if (grp->bin_attrs) for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) sysfs_remove_bin_file(kobj, *bin_attr); @@ -49,16 +49,17 @@ static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, * re-adding (if required) the file. */ if (update) - sysfs_hash_and_remove(dir_sd, NULL, - (*attr)->name); + sysfs_hash_and_remove(dir_sd, (*attr)->name, + NULL); if (grp->is_visible) { mode = grp->is_visible(kobj, *attr, i); if (!mode) continue; } - error = sysfs_add_file_mode(dir_sd, *attr, - SYSFS_KOBJ_ATTR, - (*attr)->mode | mode); + error = sysfs_add_file_mode_ns(dir_sd, *attr, + SYSFS_KOBJ_ATTR, + (*attr)->mode | mode, + NULL); if (unlikely(error)) break; } @@ -110,7 +111,7 @@ static int internal_create_group(struct kobject *kobj, int update, error = create_files(sd, kobj, grp, update); if (error) { if (grp->name) - sysfs_remove_subdir(sd); + sysfs_remove(sd); } sysfs_put(sd); return error; @@ -206,7 +207,7 @@ void sysfs_remove_group(struct kobject *kobj, struct sysfs_dirent *sd; if (grp->name) { - sd = sysfs_get_dirent(dir_sd, NULL, grp->name); + sd = sysfs_get_dirent(dir_sd, grp->name); if (!sd) { WARN(!sd, KERN_WARNING "sysfs group %p not found for kobject '%s'\n", @@ -218,7 +219,7 @@ void sysfs_remove_group(struct kobject *kobj, remove_files(sd, kobj, grp); if (grp->name) - sysfs_remove_subdir(sd); + sysfs_remove(sd); sysfs_put(sd); } @@ -261,7 +262,7 @@ int sysfs_merge_group(struct kobject *kobj, struct attribute *const *attr; int i; - dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name); + dir_sd = sysfs_get_dirent(kobj->sd, grp->name); if (!dir_sd) return -ENOENT; @@ -269,7 +270,7 @@ int sysfs_merge_group(struct kobject *kobj, error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR); if (error) { while (--i >= 0) - sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name); + sysfs_hash_and_remove(dir_sd, (*--attr)->name, NULL); } sysfs_put(dir_sd); @@ -288,10 +289,10 @@ void sysfs_unmerge_group(struct kobject *kobj, struct sysfs_dirent *dir_sd; struct attribute *const *attr; - dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name); + dir_sd = sysfs_get_dirent(kobj->sd, grp->name); if (dir_sd) { for (attr = grp->attrs; *attr; ++attr) - sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name); + sysfs_hash_and_remove(dir_sd, (*attr)->name, NULL); sysfs_put(dir_sd); } } @@ -310,7 +311,7 @@ int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, struct sysfs_dirent *dir_sd; int error = 0; - dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name); + dir_sd = sysfs_get_dirent(kobj->sd, group_name); if (!dir_sd) return -ENOENT; @@ -332,9 +333,9 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, { struct sysfs_dirent *dir_sd; - dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name); + dir_sd = sysfs_get_dirent(kobj->sd, group_name); if (dir_sd) { - sysfs_hash_and_remove(dir_sd, NULL, link_name); + sysfs_hash_and_remove(dir_sd, link_name, NULL); sysfs_put(dir_sd); } } diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 963f910..1750f79 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -258,9 +258,9 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_fop = &sysfs_file_operations; break; case SYSFS_KOBJ_BIN_ATTR: - bin_attr = sd->s_bin_attr.bin_attr; + bin_attr = sd->s_attr.bin_attr; inode->i_size = bin_attr->size; - inode->i_fop = &bin_fops; + inode->i_fop = &sysfs_bin_operations; break; case SYSFS_KOBJ_LINK: inode->i_op = &sysfs_symlink_inode_operations; @@ -314,32 +314,6 @@ void sysfs_evict_inode(struct inode *inode) sysfs_put(sd); } -int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, - const char *name) -{ - struct sysfs_addrm_cxt acxt; - struct sysfs_dirent *sd; - - if (!dir_sd) { - WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n", - name); - return -ENOENT; - } - - sysfs_addrm_start(&acxt, dir_sd); - - sd = sysfs_find_dirent(dir_sd, ns, name); - if (sd) - sysfs_remove_one(&acxt, sd); - - sysfs_addrm_finish(&acxt); - - if (sd) - return 0; - else - return -ENOENT; -} - int sysfs_permission(struct inode *inode, int mask) { struct sysfs_dirent *sd; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 2dd4507..3ae3f1b 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -33,13 +33,15 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, BUG_ON(!name || !parent_sd); - /* target->sd can go away beneath us but is protected with - * sysfs_assoc_lock. Fetch target_sd from it. + /* + * We don't own @target and it may be removed at any time. + * Synchronize using sysfs_symlink_target_lock. See + * sysfs_remove_dir() for details. */ - spin_lock(&sysfs_assoc_lock); + spin_lock(&sysfs_symlink_target_lock); if (target->sd) target_sd = sysfs_get(target->sd); - spin_unlock(&sysfs_assoc_lock); + spin_unlock(&sysfs_symlink_target_lock); error = -ENOENT; if (!target_sd) @@ -52,18 +54,18 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, ns_type = sysfs_ns_type(parent_sd); if (ns_type) - sd->s_ns = target->ktype->namespace(target); + sd->s_ns = target_sd->s_ns; sd->s_symlink.target_sd = target_sd; target_sd = NULL; /* reference is now owned by the symlink */ - sysfs_addrm_start(&acxt, parent_sd); + sysfs_addrm_start(&acxt); /* Symlinks must be between directories with the same ns_type */ if (!ns_type || (ns_type == sysfs_ns_type(sd->s_symlink.target_sd->s_parent))) { if (warn) - error = sysfs_add_one(&acxt, sd); + error = sysfs_add_one(&acxt, sd, parent_sd); else - error = __sysfs_add_one(&acxt, sd); + error = __sysfs_add_one(&acxt, sd, parent_sd); } else { error = -EINVAL; WARN(1, KERN_WARNING @@ -155,11 +157,17 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ, const char *name) { const void *ns = NULL; - spin_lock(&sysfs_assoc_lock); + + /* + * We don't own @target and it may be removed at any time. + * Synchronize using sysfs_symlink_target_lock. See + * sysfs_remove_dir() for details. + */ + spin_lock(&sysfs_symlink_target_lock); if (targ->sd && sysfs_ns_type(kobj->sd)) ns = targ->sd->s_ns; - spin_unlock(&sysfs_assoc_lock); - sysfs_hash_and_remove(kobj->sd, ns, name); + spin_unlock(&sysfs_symlink_target_lock); + sysfs_hash_and_remove(kobj->sd, name, ns); } /** @@ -176,24 +184,25 @@ void sysfs_remove_link(struct kobject *kobj, const char *name) else parent_sd = kobj->sd; - sysfs_hash_and_remove(parent_sd, NULL, name); + sysfs_hash_and_remove(parent_sd, name, NULL); } EXPORT_SYMBOL_GPL(sysfs_remove_link); /** - * sysfs_rename_link - rename symlink in object's directory. + * sysfs_rename_link_ns - rename symlink in object's directory. * @kobj: object we're acting for. * @targ: object we're pointing to. * @old: previous name of the symlink. * @new: new name of the symlink. + * @new_ns: new namespace of the symlink. * * A helper function for the common rename symlink idiom. */ -int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, - const char *old, const char *new) +int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ, + const char *old, const char *new, const void *new_ns) { struct sysfs_dirent *parent_sd, *sd = NULL; - const void *old_ns = NULL, *new_ns = NULL; + const void *old_ns = NULL; int result; if (!kobj) @@ -205,7 +214,7 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, old_ns = targ->sd->s_ns; result = -ENOENT; - sd = sysfs_get_dirent(parent_sd, old_ns, old); + sd = sysfs_get_dirent_ns(parent_sd, old, old_ns); if (!sd) goto out; @@ -215,16 +224,13 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, if (sd->s_symlink.target_sd->s_dir.kobj != targ) goto out; - if (sysfs_ns_type(parent_sd)) - new_ns = targ->ktype->namespace(targ); - - result = sysfs_rename(sd, parent_sd, new_ns, new); + result = sysfs_rename(sd, parent_sd, new, new_ns); out: sysfs_put(sd); return result; } -EXPORT_SYMBOL_GPL(sysfs_rename_link); +EXPORT_SYMBOL_GPL(sysfs_rename_link_ns); static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, struct sysfs_dirent *target_sd, char *path) diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index b6deca3..0af09fb 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -29,15 +29,13 @@ struct sysfs_elem_symlink { }; struct sysfs_elem_attr { - struct attribute *attr; + union { + struct attribute *attr; + struct bin_attribute *bin_attr; + }; struct sysfs_open_dirent *open; }; -struct sysfs_elem_bin_attr { - struct bin_attribute *bin_attr; - struct hlist_head buffers; -}; - struct sysfs_inode_attrs { struct iattr ia_iattr; void *ia_secdata; @@ -74,7 +72,6 @@ struct sysfs_dirent { struct sysfs_elem_dir s_dir; struct sysfs_elem_symlink s_symlink; struct sysfs_elem_attr s_attr; - struct sysfs_elem_bin_attr s_bin_attr; }; unsigned short s_flags; @@ -115,6 +112,7 @@ static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd) } #ifdef CONFIG_DEBUG_LOCK_ALLOC + #define sysfs_dirent_init_lockdep(sd) \ do { \ struct attribute *attr = sd->s_attr.attr; \ @@ -124,15 +122,31 @@ do { \ \ lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ } while (0) + +/* Test for attributes that want to ignore lockdep for read-locking */ +static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) +{ + int type = sysfs_type(sd); + + return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) && + sd->s_attr.attr->ignore_lockdep; +} + #else + #define sysfs_dirent_init_lockdep(sd) do {} while (0) + +static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) +{ + return true; +} + #endif /* * Context structure to be used while adding/removing nodes. */ struct sysfs_addrm_cxt { - struct sysfs_dirent *parent_sd; struct sysfs_dirent *removed; }; @@ -156,38 +170,37 @@ extern struct kmem_cache *sysfs_dir_cachep; * dir.c */ extern struct mutex sysfs_mutex; -extern spinlock_t sysfs_assoc_lock; +extern spinlock_t sysfs_symlink_target_lock; extern const struct dentry_operations sysfs_dentry_ops; extern const struct file_operations sysfs_dir_operations; extern const struct inode_operations sysfs_dir_inode_operations; -struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd); struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); void sysfs_put_active(struct sysfs_dirent *sd); -void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *parent_sd); -int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd); -int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd); -void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd); +void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt); +void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); +int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, + struct sysfs_dirent *parent_sd); +int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, + struct sysfs_dirent *parent_sd); +void sysfs_remove(struct sysfs_dirent *sd); +int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, + const void *ns); void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, - const void *ns, - const unsigned char *name); -struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, - const void *ns, - const unsigned char *name); + const unsigned char *name, + const void *ns); struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); void release_sysfs_dirent(struct sysfs_dirent *sd); int sysfs_create_subdir(struct kobject *kobj, const char *name, struct sysfs_dirent **p_sd); -void sysfs_remove_subdir(struct sysfs_dirent *sd); int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd, - const void *ns, const char *new_name); + const char *new_name, const void *new_ns); static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) { @@ -218,25 +231,21 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); -int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, - const char *name); int sysfs_inode_init(void); /* * file.c */ extern const struct file_operations sysfs_file_operations; +extern const struct file_operations sysfs_bin_operations; int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, int type); -int sysfs_add_file_mode(struct sysfs_dirent *dir_sd, - const struct attribute *attr, int type, umode_t amode); -/* - * bin.c - */ -extern const struct file_operations bin_fops; -void unmap_bin_file(struct sysfs_dirent *attr_sd); +int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type, + umode_t amode, const void *ns); +void sysfs_unmap_bin_file(struct sysfs_dirent *sd); /* * symlink.c |