#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;
- char *page;
+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.
{
struct kobject *kobj = sd->s_parent->s_dir.kobj;
- lockdep_assert_held(sd);
+ if (!sysfs_ignore_lockdep(sd))
+ lockdep_assert_held(sd);
return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
}
-/**
- * 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.
+/*
+ * 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 fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
+static int sysfs_seq_show(struct seq_file *sf, void *v)
{
- struct sysfs_dirent *attr_sd = dentry->d_fsdata;
- struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
+ struct sysfs_open_file *of = sf->private;
+ struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
const struct sysfs_ops *ops;
- int ret = 0;
+ 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);
+ of->event = atomic_read(&of->sd->s_attr.open->event);
- ops = sysfs_file_ops(attr_sd);
- count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
+ /*
+ * 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(attr_sd);
+ 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
/* Try to struggle along */
count = PAGE_SIZE - 1;
}
- if (count >= 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_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;
- mutex_lock(&buffer->mutex);
- /*
- * Fill on zero offset and the first read so that silly things like
- * "dd bs=1 skip=N" can work on sysfs files.
- */
- if (*ppos == 0 || !buffer->page) {
- 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);
+ /* 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 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;
+ 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;
- 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;
+ }
- ops = sysfs_file_ops(attr_sd);
- 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_bin_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
*
- * 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.
+ * 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 *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_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
- * @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).
* 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) {
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);
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);
}
{
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 */
- ops = sysfs_file_ops(attr_sd);
- if (WARN(!ops, 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_bin_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);
- 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;
}
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;
-
- sysfs_put_open_dirent(sd, buffer);
+ struct sysfs_open_file *of = sysfs_of(filp);
- 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
*/
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;
sysfs_put_active(attr_sd);
- if (buffer->event != atomic_read(&od->event))
+ if (of->event != atomic_read(&od->event))
goto trigger;
return DEFAULT_POLLMASK;
EXPORT_SYMBOL_GPL(sysfs_notify);
const struct file_operations sysfs_file_operations = {
- .read = sysfs_read_file,
+ .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,
}
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;
projects / karo-tx-linux.git / blobdiff