#include <linux/poll.h>
#include <linux/list.h>
#include <linux/mutex.h>
+#include <linux/limits.h>
#include <asm/uaccess.h>
#include "sysfs.h"
+/* used in crash dumps to help with debugging */
+static char last_sysfs_file[PATH_MAX];
+void sysfs_printk_last_file(void)
+{
+ printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
+}
+
/*
* There's one sysfs_buffer for each open file and one
* sysfs_open_dirent for each sysfs_dirent with one or more open
struct sysfs_open_dirent *od, *new_od = NULL;
retry:
- spin_lock(&sysfs_open_dirent_lock);
+ spin_lock_irq(&sysfs_open_dirent_lock);
if (!sd->s_attr.open && new_od) {
sd->s_attr.open = new_od;
list_add_tail(&buffer->list, &od->buffers);
}
- spin_unlock(&sysfs_open_dirent_lock);
+ spin_unlock_irq(&sysfs_open_dirent_lock);
if (od) {
kfree(new_od);
struct sysfs_buffer *buffer)
{
struct sysfs_open_dirent *od = sd->s_attr.open;
+ unsigned long flags;
- spin_lock(&sysfs_open_dirent_lock);
+ spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
list_del(&buffer->list);
if (atomic_dec_and_test(&od->refcnt))
else
od = NULL;
- spin_unlock(&sysfs_open_dirent_lock);
+ spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
kfree(od);
}
struct sysfs_buffer *buffer;
struct sysfs_ops *ops;
int error = -EACCES;
+ char *p;
+
+ p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
+ if (p)
+ memmove(last_sysfs_file, p, strlen(p) + 1);
/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active_two(attr_sd))
if (kobj->ktype && kobj->ktype->sysfs_ops)
ops = kobj->ktype->sysfs_ops;
else {
- printk(KERN_ERR "missing sysfs attribute operations for "
+ WARN(1, KERN_ERR "missing sysfs attribute operations for "
"kobject: %s\n", kobject_name(kobj));
- WARN_ON(1);
goto err_out;
}
if (buffer->event != atomic_read(&od->event))
goto trigger;
- return 0;
+ return DEFAULT_POLLMASK;
trigger:
buffer->needs_read_fill = 1;
- return POLLERR|POLLPRI;
+ return DEFAULT_POLLMASK|POLLERR|POLLPRI;
}
-void sysfs_notify(struct kobject *k, char *dir, char *attr)
+void sysfs_notify_dirent(struct sysfs_dirent *sd)
+{
+ struct sysfs_open_dirent *od;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
+
+ 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;
sd = sysfs_find_dirent(sd, dir);
if (sd && attr)
sd = sysfs_find_dirent(sd, attr);
- if (sd) {
- struct sysfs_open_dirent *od;
-
- spin_lock(&sysfs_open_dirent_lock);
-
- od = sd->s_attr.open;
- if (od) {
- atomic_inc(&od->event);
- wake_up_interruptible(&od->poll);
- }
-
- spin_unlock(&sysfs_open_dirent_lock);
- }
+ if (sd)
+ sysfs_notify_dirent(sd);
mutex_unlock(&sysfs_mutex);
}
*/
int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
{
- struct sysfs_dirent *victim_sd = NULL;
- struct dentry *victim = NULL;
- struct inode * inode;
+ struct sysfs_dirent *sd;
struct iattr newattrs;
int rc;
- rc = -ENOENT;
- victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
- if (!victim_sd)
- goto out;
+ mutex_lock(&sysfs_mutex);
- mutex_lock(&sysfs_rename_mutex);
- victim = sysfs_get_dentry(victim_sd);
- mutex_unlock(&sysfs_rename_mutex);
- if (IS_ERR(victim)) {
- rc = PTR_ERR(victim);
- victim = NULL;
+ rc = -ENOENT;
+ sd = sysfs_find_dirent(kobj->sd, attr->name);
+ if (!sd)
goto out;
- }
-
- inode = victim->d_inode;
-
- mutex_lock(&inode->i_mutex);
- newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
- newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
- newattrs.ia_ctime = current_fs_time(inode->i_sb);
- rc = sysfs_setattr(victim, &newattrs);
+ newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO);
+ newattrs.ia_valid = ATTR_MODE;
+ rc = sysfs_sd_setattr(sd, &newattrs);
- if (rc == 0) {
- fsnotify_change(victim, newattrs.ia_valid);
- mutex_lock(&sysfs_mutex);
- victim_sd->s_mode = newattrs.ia_mode;
- mutex_unlock(&sysfs_mutex);
- }
-
- mutex_unlock(&inode->i_mutex);
out:
- dput(victim);
- sysfs_put(victim_sd);
+ mutex_unlock(&sysfs_mutex);
return rc;
}
EXPORT_SYMBOL_GPL(sysfs_chmod_file);
EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
struct sysfs_schedule_callback_struct {
- struct kobject *kobj;
+ 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,
(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);
}
* 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.
+ * 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;
+ 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);
ss->data = data;
ss->owner = owner;
INIT_WORK(&ss->work, sysfs_schedule_callback_work);
- schedule_work(&ss->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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff