diff options
Diffstat (limited to 'fs/sysfs/file.c')
-rw-r--r-- | fs/sysfs/file.c | 872 |
1 files changed, 591 insertions, 281 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 15ef5eb13663..79b5da2acbe1 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; |