diff options
Diffstat (limited to 'fs/sysfs/file.c')
| -rw-r--r-- | fs/sysfs/file.c | 961 |
1 files changed, 182 insertions, 779 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 35e7d08fe629..810cf6e613e5 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -14,70 +14,23 @@ #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" +#include "../kernfs/kernfs-internal.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 + * Determine ktype->sysfs_ops for the given kernfs_node. This function * must be called while holding an active reference. */ -static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) +static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) { - struct kobject *kobj = sd->s_parent->s_dir.kobj; + struct kobject *kobj = kn->parent->priv; - if (!sysfs_ignore_lockdep(sd)) - lockdep_assert_held(sd); + if (kn->flags & KERNFS_LOCKDEP) + lockdep_assert_held(kn); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } @@ -86,13 +39,13 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) * 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) +static int sysfs_kf_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; + struct kernfs_open_file *of = sf->private; + struct kobject *kobj = of->kn->parent->priv; + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); ssize_t count; + char *buf; /* acquire buffer and ensure that it's >= PAGE_SIZE */ count = seq_get_buf(sf, &buf); @@ -102,34 +55,15 @@ static int sysfs_seq_show(struct seq_file *sf, void *v) } /* - * 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. + * Invoke show(). Control may reach here via seq file lseek even + * if @ops->show() isn't implemented. */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) { - mutex_unlock(&of->mutex); - return -ENODEV; + if (ops->show) { + count = ops->show(kobj, of->kn->priv, buf); + if (count < 0) + return count; } - 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. @@ -144,726 +78,194 @@ static int sysfs_seq_show(struct seq_file *sf, void *v) 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) +static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, + size_t count, loff_t pos) { - 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; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->parent->priv; + loff_t size = file_inode(of->file)->i_size; - if (!bytes) + if (!count) return 0; if (size) { - if (offs > size) + if (pos > 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; + if (pos + count > size) + count = size - pos; } - pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); - - *off = offs + count; + if (!battr->read) + return -EIO; - out_free: - kfree(buf); - return count; + return battr->read(of->file, kobj, battr, buf, pos, 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) +/* kernfs write callback for regular sysfs files */ +static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, + size_t count, loff_t pos) { - 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; - } + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); + struct kobject *kobj = of->kn->parent->priv; - if (sysfs_is_bin(of->sd)) { - struct bin_attribute *battr = of->sd->s_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); + if (!count) + return 0; - return rc; + return ops->store(kobj, of->kn->priv, buf, count); } -/** - * 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) +/* kernfs write callback for bin sysfs files */ +static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, + size_t count, loff_t pos) { - 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; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->parent->priv; + loff_t size = file_inode(of->file)->i_size; - if (sysfs_is_bin(of->sd) && size) { - if (size <= *ppos) + if (size) { + if (size <= pos) return 0; - len = min_t(ssize_t, len, size - *ppos); + count = min_t(ssize_t, count, size - pos); } - - if (!len) + if (!count) return 0; - buf = kmalloc(len + 1, GFP_KERNEL); - if (!buf) - return -ENOMEM; + if (!battr->write) + return -EIO; - 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); + return battr->write(of->file, kobj, battr, buf, pos, count); } -static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +static int sysfs_kf_bin_mmap(struct kernfs_open_file *of, + struct vm_area_struct *vma) { - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->parent->priv; - 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; + return battr->mmap(of->file, kobj, battr, vma); } -static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma, - struct vm_fault *vmf) +void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return VM_FAULT_SIGBUS; + struct kernfs_node *kn = kobj->sd, *tmp; - 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); + if (kn && dir) + kn = kernfs_find_and_get(kn, dir); 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; + kernfs_get(kn); - /* - * 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; + if (kn && attr) { + tmp = kernfs_find_and_get(kn, attr); + kernfs_put(kn); + kn = tmp; } - 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; + if (kn) { + kernfs_notify(kn); + kernfs_put(kn); } +} +EXPORT_SYMBOL_GPL(sysfs_notify); - /* not there, initialize a new one and retry */ - new_od = kmalloc(sizeof(*new_od), GFP_KERNEL); - if (!new_od) - return -ENOMEM; +static const struct kernfs_ops sysfs_file_kfops_empty = { +}; - 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; -} +static const struct kernfs_ops sysfs_file_kfops_ro = { + .seq_show = sysfs_kf_seq_show, +}; -/** - * 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; +static const struct kernfs_ops sysfs_file_kfops_wo = { + .write = sysfs_kf_write, +}; - mutex_lock(&sysfs_open_file_mutex); - spin_lock_irqsave(&sysfs_open_dirent_lock, flags); +static const struct kernfs_ops sysfs_file_kfops_rw = { + .seq_show = sysfs_kf_seq_show, + .write = sysfs_kf_write, +}; - if (of) - list_del(&of->list); +static const struct kernfs_ops sysfs_bin_kfops_ro = { + .read = sysfs_kf_bin_read, +}; - if (atomic_dec_and_test(&od->refcnt)) - sd->s_attr.open = NULL; - else - od = NULL; +static const struct kernfs_ops sysfs_bin_kfops_wo = { + .write = sysfs_kf_bin_write, +}; - spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); - mutex_unlock(&sysfs_open_file_mutex); +static const struct kernfs_ops sysfs_bin_kfops_rw = { + .read = sysfs_kf_bin_read, + .write = sysfs_kf_bin_write, +}; - kfree(od); -} +static const struct kernfs_ops sysfs_bin_kfops_mmap = { + .read = sysfs_kf_bin_read, + .write = sysfs_kf_bin_write, + .mmap = sysfs_kf_bin_mmap, +}; -static int sysfs_open_file(struct inode *inode, struct file *file) +int sysfs_add_file_mode_ns(struct kernfs_node *parent, + const struct attribute *attr, bool is_bin, + umode_t mode, const void *ns) { - 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; + struct lock_class_key *key = NULL; + const struct kernfs_ops *ops; + struct kernfs_node *kn; + loff_t size; - if (sysfs_is_bin(attr_sd)) { - struct bin_attribute *battr = attr_sd->s_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); + if (!is_bin) { + struct kobject *kobj = parent->priv; + const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; /* every kobject with an attribute needs a ktype assigned */ - if (WARN(!ops, KERN_ERR + if (WARN(!sysfs_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; - - /* - * The following is done to give a different lockdep key to - * @of->mutex for files which implement mmap. This is a rather - * crude way to avoid false positive lockdep warning around - * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and - * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under - * which mm->mmap_sem nests, while holding @of->mutex. As each - * open file has a separate mutex, it's okay as long as those don't - * happen on the same file. At this point, we can't easily give - * each file a separate locking class. Let's differentiate on - * whether the file is bin or not for now. - */ - if (sysfs_is_bin(attr_sd)) - mutex_init(&of->mutex); - else - 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); + return -EINVAL; + + if (sysfs_ops->show && sysfs_ops->store) + ops = &sysfs_file_kfops_rw; + else if (sysfs_ops->show) + ops = &sysfs_file_kfops_ro; + else if (sysfs_ops->store) + ops = &sysfs_file_kfops_wo; + else + ops = &sysfs_file_kfops_empty; + + size = PAGE_SIZE; + } else { + struct bin_attribute *battr = (void *)attr; + + if (battr->mmap) + ops = &sysfs_bin_kfops_mmap; + else if (battr->read && battr->write) + ops = &sysfs_bin_kfops_rw; + else if (battr->read) + ops = &sysfs_bin_kfops_ro; + else if (battr->write) + ops = &sysfs_bin_kfops_wo; + else + ops = &sysfs_file_kfops_empty; + + size = battr->size; } - 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); - } +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (!attr->ignore_lockdep) + key = attr->key ?: (struct lock_class_key *)&attr->skey; +#endif + kn = __kernfs_create_file(parent, attr->name, mode, size, ops, + (void *)attr, ns, true, key); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, attr->name); + return PTR_ERR(kn); } - - 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 = generic_file_llseek, - .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; + return 0; } - -int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, - int type) +int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr, + bool is_bin) { - return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL); + return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL); } /** @@ -877,8 +279,7 @@ int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, { BUG_ON(!kobj || !kobj->sd || !attr); - return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR, - attr->mode, ns); + return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns); } EXPORT_SYMBOL_GPL(sysfs_create_file_ns); @@ -906,19 +307,21 @@ EXPORT_SYMBOL_GPL(sysfs_create_files); int sysfs_add_file_to_group(struct kobject *kobj, const struct attribute *attr, const char *group) { - struct sysfs_dirent *dir_sd; + struct kernfs_node *parent; int error; - if (group) - dir_sd = sysfs_get_dirent(kobj->sd, group); - else - dir_sd = sysfs_get(kobj->sd); + if (group) { + parent = kernfs_find_and_get(kobj->sd, group); + } else { + parent = kobj->sd; + kernfs_get(parent); + } - if (!dir_sd) + if (!parent) return -ENOENT; - error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR); - sysfs_put(dir_sd); + error = sysfs_add_file(parent, attr, false); + kernfs_put(parent); return error; } @@ -934,23 +337,20 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, umode_t mode) { - struct sysfs_dirent *sd; + struct kernfs_node *kn; struct iattr newattrs; int rc; - mutex_lock(&sysfs_mutex); - - rc = -ENOENT; - sd = sysfs_find_dirent(kobj->sd, attr->name, NULL); - if (!sd) - goto out; + kn = kernfs_find_and_get(kobj->sd, attr->name); + if (!kn) + return -ENOENT; - newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); + newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE; - rc = sysfs_sd_setattr(sd, &newattrs); - out: - mutex_unlock(&sysfs_mutex); + rc = kernfs_setattr(kn, &newattrs); + + kernfs_put(kn); return rc; } EXPORT_SYMBOL_GPL(sysfs_chmod_file); @@ -966,9 +366,9 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file); void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, const void *ns) { - struct sysfs_dirent *dir_sd = kobj->sd; + struct kernfs_node *parent = kobj->sd; - sysfs_hash_and_remove(dir_sd, attr->name, ns); + kernfs_remove_by_name_ns(parent, attr->name, ns); } EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); @@ -989,15 +389,18 @@ EXPORT_SYMBOL_GPL(sysfs_remove_files); void sysfs_remove_file_from_group(struct kobject *kobj, const struct attribute *attr, const char *group) { - struct sysfs_dirent *dir_sd; + struct kernfs_node *parent; - 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); + if (group) { + parent = kernfs_find_and_get(kobj->sd, group); + } else { + parent = kobj->sd; + kernfs_get(parent); + } + + if (parent) { + kernfs_remove_by_name(parent, attr->name); + kernfs_put(parent); } } EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); @@ -1012,7 +415,7 @@ int sysfs_create_bin_file(struct kobject *kobj, { BUG_ON(!kobj || !kobj->sd || !attr); - return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); + return sysfs_add_file(kobj->sd, &attr->attr, true); } EXPORT_SYMBOL_GPL(sysfs_create_bin_file); @@ -1024,7 +427,7 @@ EXPORT_SYMBOL_GPL(sysfs_create_bin_file); void sysfs_remove_bin_file(struct kobject *kobj, const struct bin_attribute *attr) { - sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL); + kernfs_remove_by_name(kobj->sd, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |