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- /*
- * fs/sysfs/file.c - sysfs regular (text) file implementation
- *
- * Copyright (c) 2001-3 Patrick Mochel
- * 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.
- */
- #include <linux/module.h>
- #include <linux/kobject.h>
- #include <linux/kallsyms.h>
- #include <linux/slab.h>
- #include <linux/fsnotify.h>
- #include <linux/namei.h>
- #include <linux/poll.h>
- #include <linux/list.h>
- #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_open_file for each open file and one sysfs_open_dirent
- * for each sysfs_dirent with one or more open files.
- *
- * 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 files; /* goes through sysfs_open_file.list */
- };
- struct sysfs_open_file {
- struct sysfs_dirent *sd;
- struct file *file;
- struct mutex mutex;
- int event;
- struct list_head list;
- bool mmapped;
- const struct vm_operations_struct *vm_ops;
- };
- 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 const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
- {
- 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;
- /* 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 @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;
- }
- of->event = atomic_read(&of->sd->s_attr.open->event);
- /*
- * 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
- * indicate truncated result or overflow in normal use cases.
- */
- if (count >= (ssize_t)PAGE_SIZE) {
- print_symbol("fill_read_buffer: %s returned bad count\n",
- (unsigned long)ops->show);
- /* Try to struggle along */
- count = PAGE_SIZE - 1;
- }
- seq_commit(sf, count);
- return 0;
- }
- /*
- * 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_bin_read(struct file *file, char __user *userbuf,
- size_t bytes, loff_t *off)
- {
- struct sysfs_open_file *of = sysfs_of(file);
- struct bin_attribute *battr = of->sd->s_bin_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;
- if (size) {
- if (offs > size)
- return 0;
- if (offs + count > size)
- count = size - offs;
- }
- buf = kmalloc(count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
- /* 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
- * @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 it with @buf.
- */
- static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
- size_t count)
- {
- struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
- int rc = 0;
- /*
- * 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;
- }
- if (sysfs_is_bin(of->sd)) {
- struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
- 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
- * @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().
- *
- * 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 *user_buf,
- size_t count, loff_t *ppos)
- {
- 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);
- }
- 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;
- 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_bin_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;
- rc = -EINVAL;
- 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
- * @of: sysfs_open_file for this instance of open
- *
- * If @sd->s_attr.open exists, increment its reference count;
- * otherwise, create one. @of is chained to the files list.
- *
- * LOCKING:
- * Kernel thread context (may sleep).
- *
- * RETURNS:
- * 0 on success, -errno on failure.
- */
- static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
- 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) {
- sd->s_attr.open = new_od;
- new_od = NULL;
- }
- od = sd->s_attr.open;
- if (od) {
- atomic_inc(&od->refcnt);
- 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);
- return 0;
- }
- /* not there, initialize a new one and retry */
- new_od = kmalloc(sizeof(*new_od), GFP_KERNEL);
- if (!new_od)
- return -ENOMEM;
- atomic_set(&new_od->refcnt, 0);
- atomic_set(&new_od->event, 1);
- init_waitqueue_head(&new_od->poll);
- INIT_LIST_HEAD(&new_od->files);
- goto retry;
- }
- /**
- * sysfs_put_open_dirent - put sysfs_open_dirent
- * @sd: target sysfs_dirent
- * @of: associated sysfs_open_file
- *
- * 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_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);
- 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);
- }
- 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_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;
- if (sysfs_is_bin(attr_sd)) {
- struct bin_attribute *battr = attr_sd->s_bin_attr.bin_attr;
- has_read = battr->read || battr->mmap;
- has_write = battr->write || battr->mmap;
- } else {
- const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);
- /* 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;
- }
- /* 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;
- of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL);
- if (!of)
- goto err_out;
- mutex_init(&of->mutex);
- of->sd = attr_sd;
- of->file = file;
- /*
- * 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_close:
- single_release(inode, file);
- err_free:
- kfree(of);
- err_out:
- sysfs_put_active(attr_sd);
- return error;
- }
- static int sysfs_release(struct inode *inode, struct file *filp)
- {
- struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
- struct sysfs_open_file *of = sysfs_of(filp);
- 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
- * manager for the kobject supports notification), poll will
- * return POLLERR|POLLPRI, and select will return the fd whether
- * it is waiting for read, write, or exceptions.
- * Once poll/select indicates that the value has changed, you
- * need to close and re-open the file, or seek to 0 and read again.
- * Reminder: this only works for attributes which actively support
- * it, and it is not possible to test an attribute from userspace
- * to see if it supports poll (Neither 'poll' nor 'select' return
- * an appropriate error code). When in doubt, set a suitable timeout value.
- */
- static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
- {
- 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;
- /* need parent for the kobj, grab both */
- if (!sysfs_get_active(attr_sd))
- goto trigger;
- poll_wait(filp, &od->poll, wait);
- sysfs_put_active(attr_sd);
- if (of->event != atomic_read(&od->event))
- goto trigger;
- return DEFAULT_POLLMASK;
- trigger:
- return DEFAULT_POLLMASK|POLLERR|POLLPRI;
- }
- void sysfs_notify_dirent(struct sysfs_dirent *sd)
- {
- struct sysfs_open_dirent *od;
- unsigned long flags;
- spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
- if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) {
- od = sd->s_attr.open;
- if (od) {
- atomic_inc(&od->event);
- wake_up_interruptible(&od->poll);
- }
- }
- spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
- }
- EXPORT_SYMBOL_GPL(sysfs_notify_dirent);
- void sysfs_notify(struct kobject *k, const char *dir, const char *attr)
- {
- struct sysfs_dirent *sd = k->sd;
- mutex_lock(&sysfs_mutex);
- if (sd && dir)
- sd = sysfs_find_dirent(sd, dir, NULL);
- if (sd && attr)
- sd = sysfs_find_dirent(sd, attr, NULL);
- if (sd)
- sysfs_notify_dirent(sd);
- mutex_unlock(&sysfs_mutex);
- }
- EXPORT_SYMBOL_GPL(sysfs_notify);
- const struct file_operations sysfs_file_operations = {
- .read = seq_read,
- .write = sysfs_write_file,
- .llseek = seq_lseek,
- .open = sysfs_open_file,
- .release = sysfs_release,
- .poll = sysfs_poll,
- };
- 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_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;
- int rc;
- sd = sysfs_new_dirent(attr->name, mode, type);
- if (!sd)
- return -ENOMEM;
- sd->s_ns = ns;
- sd->s_attr.attr = (void *)attr;
- sysfs_dirent_init_lockdep(sd);
- sysfs_addrm_start(&acxt);
- rc = sysfs_add_one(&acxt, sd, dir_sd);
- sysfs_addrm_finish(&acxt);
- if (rc)
- sysfs_put(sd);
- return rc;
- }
- int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
- int type)
- {
- return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL);
- }
- /**
- * 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_ns(struct kobject *kobj, const struct attribute *attr,
- const void *ns)
- {
- BUG_ON(!kobj || !kobj->sd || !attr);
- return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR,
- attr->mode, ns);
- }
- EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
- int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
- {
- int err = 0;
- int i;
- for (i = 0; ptr[i] && !err; i++)
- err = sysfs_create_file(kobj, ptr[i]);
- if (err)
- while (--i >= 0)
- sysfs_remove_file(kobj, ptr[i]);
- return err;
- }
- EXPORT_SYMBOL_GPL(sysfs_create_files);
- /**
- * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
- * @kobj: object we're acting for.
- * @attr: attribute descriptor.
- * @group: group name.
- */
- int sysfs_add_file_to_group(struct kobject *kobj,
- const struct attribute *attr, const char *group)
- {
- struct sysfs_dirent *dir_sd;
- int error;
- if (group)
- dir_sd = sysfs_get_dirent(kobj->sd, group);
- else
- dir_sd = sysfs_get(kobj->sd);
- if (!dir_sd)
- return -ENOENT;
- error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR);
- sysfs_put(dir_sd);
- return error;
- }
- EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
- /**
- * sysfs_chmod_file - update the modified mode value on an object attribute.
- * @kobj: object we're acting for.
- * @attr: attribute descriptor.
- * @mode: file permissions.
- *
- */
- int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
- umode_t mode)
- {
- struct sysfs_dirent *sd;
- struct iattr newattrs;
- int rc;
- mutex_lock(&sysfs_mutex);
- rc = -ENOENT;
- sd = sysfs_find_dirent(kobj->sd, attr->name, NULL);
- if (!sd)
- goto out;
- newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO);
- newattrs.ia_valid = ATTR_MODE;
- rc = sysfs_sd_setattr(sd, &newattrs);
- out:
- mutex_unlock(&sysfs_mutex);
- return rc;
- }
- EXPORT_SYMBOL_GPL(sysfs_chmod_file);
- /**
- * 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 namespace tag and kill the victim.
- */
- void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
- const void *ns)
- {
- struct sysfs_dirent *dir_sd = kobj->sd;
- sysfs_hash_and_remove(dir_sd, attr->name, ns);
- }
- EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
- void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
- {
- int i;
- for (i = 0; ptr[i]; i++)
- sysfs_remove_file(kobj, ptr[i]);
- }
- EXPORT_SYMBOL_GPL(sysfs_remove_files);
- /**
- * sysfs_remove_file_from_group - remove an attribute file from a group.
- * @kobj: object we're acting for.
- * @attr: attribute descriptor.
- * @group: group name.
- */
- void sysfs_remove_file_from_group(struct kobject *kobj,
- const struct attribute *attr, const char *group)
- {
- struct sysfs_dirent *dir_sd;
- if (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, 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;
- void (*func)(void *);
- void *data;
- struct module *owner;
- struct work_struct work;
- };
- static struct workqueue_struct *sysfs_workqueue;
- static DEFINE_MUTEX(sysfs_workq_mutex);
- static LIST_HEAD(sysfs_workq);
- static void sysfs_schedule_callback_work(struct work_struct *work)
- {
- struct sysfs_schedule_callback_struct *ss = container_of(work,
- struct sysfs_schedule_callback_struct, work);
- (ss->func)(ss->data);
- kobject_put(ss->kobj);
- module_put(ss->owner);
- mutex_lock(&sysfs_workq_mutex);
- list_del(&ss->workq_list);
- mutex_unlock(&sysfs_workq_mutex);
- kfree(ss);
- }
- /**
- * sysfs_schedule_callback - helper to schedule a callback for a kobject
- * @kobj: object we're acting for.
- * @func: callback function to invoke later.
- * @data: argument to pass to @func.
- * @owner: module owning the callback code
- *
- * sysfs attribute methods must not unregister themselves or their parent
- * kobject (which would amount to the same thing). Attempts to do so will
- * deadlock, since unregistration is mutually exclusive with driver
- * callbacks.
- *
- * Instead methods can call this routine, which will attempt to allocate
- * and schedule a workqueue request to call back @func with @data as its
- * argument in the workqueue's process context. @kobj will be pinned
- * until @func returns.
- *
- * Returns 0 if the request was submitted, -ENOMEM if storage could not
- * be allocated, -ENODEV if a reference to @owner isn't available,
- * -EAGAIN if a callback has already been scheduled for @kobj.
- */
- int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
- void *data, struct module *owner)
- {
- struct sysfs_schedule_callback_struct *ss, *tmp;
- if (!try_module_get(owner))
- return -ENODEV;
- mutex_lock(&sysfs_workq_mutex);
- list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list)
- if (ss->kobj == kobj) {
- module_put(owner);
- mutex_unlock(&sysfs_workq_mutex);
- return -EAGAIN;
- }
- mutex_unlock(&sysfs_workq_mutex);
- if (sysfs_workqueue == NULL) {
- sysfs_workqueue = create_singlethread_workqueue("sysfsd");
- if (sysfs_workqueue == NULL) {
- module_put(owner);
- return -ENOMEM;
- }
- }
- ss = kmalloc(sizeof(*ss), GFP_KERNEL);
- if (!ss) {
- module_put(owner);
- return -ENOMEM;
- }
- kobject_get(kobj);
- ss->kobj = kobj;
- ss->func = func;
- ss->data = data;
- ss->owner = owner;
- INIT_WORK(&ss->work, sysfs_schedule_callback_work);
- INIT_LIST_HEAD(&ss->workq_list);
- mutex_lock(&sysfs_workq_mutex);
- list_add_tail(&ss->workq_list, &sysfs_workq);
- mutex_unlock(&sysfs_workq_mutex);
- queue_work(sysfs_workqueue, &ss->work);
- return 0;
- }
- EXPORT_SYMBOL_GPL(sysfs_schedule_callback);
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