X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=fs%2Fsysfs%2Ffile.c;h=561a9c050cef687ebc48649af895f163572c2476;hb=197e2eabc90c203d1086916b7f66694ba5fbb937;hp=e7735f643cd1b03eab8560479d6f691e387ce218;hpb=8e24eea728068bbeb6a3c500b848f883a20bf225;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index e7735f6..561a9c0 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -14,14 +14,23 @@ #include #include #include +#include #include #include #include #include +#include #include #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 @@ -327,6 +336,11 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 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)) @@ -336,9 +350,8 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 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; } @@ -433,14 +446,30 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait) 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; + + 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); +} +EXPORT_SYMBOL_GPL(sysfs_notify_dirent); + +void sysfs_notify(struct kobject *k, const char *dir, const char *attr) { struct sysfs_dirent *sd = k->sd; @@ -450,19 +479,8 @@ void sysfs_notify(struct kobject *k, char *dir, char *attr) 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); } @@ -585,9 +603,11 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; - rc = notify_change(victim, &newattrs); + newattrs.ia_ctime = current_fs_time(inode->i_sb); + rc = sysfs_setattr(victim, &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); @@ -639,13 +659,17 @@ void sysfs_remove_file_from_group(struct kobject *kobj, 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, @@ -654,6 +678,9 @@ static void sysfs_schedule_callback_work(struct work_struct *work) (ss->func)(ss->data); kobject_put(ss->kobj); module_put(ss->owner); + mutex_lock(&sysfs_workq_mutex); + list_del(&ss->workq_list); + mutex_unlock(&sysfs_workq_mutex); kfree(ss); } @@ -675,15 +702,34 @@ static void sysfs_schedule_callback_work(struct work_struct *work) * 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); @@ -695,7 +741,11 @@ int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), 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);