diff options
author | Christoph Hellwig <hch@lst.de> | 2021-06-24 09:38:42 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2021-06-24 12:00:22 -0600 |
commit | d5870edfa3afc4608231267ea3b8e4beb3eab1ee (patch) | |
tree | 8e0f186a3b51277ab5c2c1e2a6a8de0763915669 /block/genhd.c | |
parent | 60b6a7e6a0f4382cd689f9afdac816964fec2921 (diff) |
block: move the disk events code to a separate file
Move the code for handling disk events from genhd.c into a new file
as it isn't very related to the rest of the file while at the same
time requiring lots of forward declarations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210624073843.251178-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/genhd.c')
-rw-r--r-- | block/genhd.c | 492 |
1 files changed, 0 insertions, 492 deletions
diff --git a/block/genhd.c b/block/genhd.c index 5f5628216295..4f879deede9a 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -33,13 +33,6 @@ static struct kobject *block_depr; #define NR_EXT_DEVT (1 << MINORBITS) static DEFINE_IDA(ext_devt_ida); -static void disk_check_events(struct disk_events *ev, - unsigned int *clearing_ptr); -static void disk_alloc_events(struct gendisk *disk); -static void disk_add_events(struct gendisk *disk); -static void disk_del_events(struct gendisk *disk); -static void disk_release_events(struct gendisk *disk); - void set_capacity(struct gendisk *disk, sector_t sectors) { struct block_device *bdev = disk->part0; @@ -1367,488 +1360,3 @@ int bdev_read_only(struct block_device *bdev) return bdev->bd_read_only || get_disk_ro(bdev->bd_disk); } EXPORT_SYMBOL(bdev_read_only); - -/* - * Disk events - monitor disk events like media change and eject request. - */ -struct disk_events { - struct list_head node; /* all disk_event's */ - struct gendisk *disk; /* the associated disk */ - spinlock_t lock; - - struct mutex block_mutex; /* protects blocking */ - int block; /* event blocking depth */ - unsigned int pending; /* events already sent out */ - unsigned int clearing; /* events being cleared */ - - long poll_msecs; /* interval, -1 for default */ - struct delayed_work dwork; -}; - -static const char *disk_events_strs[] = { - [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change", - [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request", -}; - -static char *disk_uevents[] = { - [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1", - [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1", -}; - -/* list of all disk_events */ -static DEFINE_MUTEX(disk_events_mutex); -static LIST_HEAD(disk_events); - -/* disable in-kernel polling by default */ -static unsigned long disk_events_dfl_poll_msecs; - -static unsigned long disk_events_poll_jiffies(struct gendisk *disk) -{ - struct disk_events *ev = disk->ev; - long intv_msecs = 0; - - /* - * If device-specific poll interval is set, always use it. If - * the default is being used, poll if the POLL flag is set. - */ - if (ev->poll_msecs >= 0) - intv_msecs = ev->poll_msecs; - else if (disk->event_flags & DISK_EVENT_FLAG_POLL) - intv_msecs = disk_events_dfl_poll_msecs; - - return msecs_to_jiffies(intv_msecs); -} - -/** - * disk_block_events - block and flush disk event checking - * @disk: disk to block events for - * - * On return from this function, it is guaranteed that event checking - * isn't in progress and won't happen until unblocked by - * disk_unblock_events(). Events blocking is counted and the actual - * unblocking happens after the matching number of unblocks are done. - * - * Note that this intentionally does not block event checking from - * disk_clear_events(). - * - * CONTEXT: - * Might sleep. - */ -void disk_block_events(struct gendisk *disk) -{ - struct disk_events *ev = disk->ev; - unsigned long flags; - bool cancel; - - if (!ev) - return; - - /* - * Outer mutex ensures that the first blocker completes canceling - * the event work before further blockers are allowed to finish. - */ - mutex_lock(&ev->block_mutex); - - spin_lock_irqsave(&ev->lock, flags); - cancel = !ev->block++; - spin_unlock_irqrestore(&ev->lock, flags); - - if (cancel) - cancel_delayed_work_sync(&disk->ev->dwork); - - mutex_unlock(&ev->block_mutex); -} - -static void __disk_unblock_events(struct gendisk *disk, bool check_now) -{ - struct disk_events *ev = disk->ev; - unsigned long intv; - unsigned long flags; - - spin_lock_irqsave(&ev->lock, flags); - - if (WARN_ON_ONCE(ev->block <= 0)) - goto out_unlock; - - if (--ev->block) - goto out_unlock; - - intv = disk_events_poll_jiffies(disk); - if (check_now) - queue_delayed_work(system_freezable_power_efficient_wq, - &ev->dwork, 0); - else if (intv) - queue_delayed_work(system_freezable_power_efficient_wq, - &ev->dwork, intv); -out_unlock: - spin_unlock_irqrestore(&ev->lock, flags); -} - -/** - * disk_unblock_events - unblock disk event checking - * @disk: disk to unblock events for - * - * Undo disk_block_events(). When the block count reaches zero, it - * starts events polling if configured. - * - * CONTEXT: - * Don't care. Safe to call from irq context. - */ -void disk_unblock_events(struct gendisk *disk) -{ - if (disk->ev) - __disk_unblock_events(disk, false); -} - -/** - * disk_flush_events - schedule immediate event checking and flushing - * @disk: disk to check and flush events for - * @mask: events to flush - * - * Schedule immediate event checking on @disk if not blocked. Events in - * @mask are scheduled to be cleared from the driver. Note that this - * doesn't clear the events from @disk->ev. - * - * CONTEXT: - * If @mask is non-zero must be called with disk->open_mutex held. - */ -void disk_flush_events(struct gendisk *disk, unsigned int mask) -{ - struct disk_events *ev = disk->ev; - - if (!ev) - return; - - spin_lock_irq(&ev->lock); - ev->clearing |= mask; - if (!ev->block) - mod_delayed_work(system_freezable_power_efficient_wq, - &ev->dwork, 0); - spin_unlock_irq(&ev->lock); -} - -/** - * disk_clear_events - synchronously check, clear and return pending events - * @disk: disk to fetch and clear events from - * @mask: mask of events to be fetched and cleared - * - * Disk events are synchronously checked and pending events in @mask - * are cleared and returned. This ignores the block count. - * - * CONTEXT: - * Might sleep. - */ -static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) -{ - struct disk_events *ev = disk->ev; - unsigned int pending; - unsigned int clearing = mask; - - if (!ev) - return 0; - - disk_block_events(disk); - - /* - * store the union of mask and ev->clearing on the stack so that the - * race with disk_flush_events does not cause ambiguity (ev->clearing - * can still be modified even if events are blocked). - */ - spin_lock_irq(&ev->lock); - clearing |= ev->clearing; - ev->clearing = 0; - spin_unlock_irq(&ev->lock); - - disk_check_events(ev, &clearing); - /* - * if ev->clearing is not 0, the disk_flush_events got called in the - * middle of this function, so we want to run the workfn without delay. - */ - __disk_unblock_events(disk, ev->clearing ? true : false); - - /* then, fetch and clear pending events */ - spin_lock_irq(&ev->lock); - pending = ev->pending & mask; - ev->pending &= ~mask; - spin_unlock_irq(&ev->lock); - WARN_ON_ONCE(clearing & mask); - - return pending; -} - -/** - * bdev_check_media_change - check if a removable media has been changed - * @bdev: block device to check - * - * Check whether a removable media has been changed, and attempt to free all - * dentries and inodes and invalidates all block device page cache entries in - * that case. - * - * Returns %true if the block device changed, or %false if not. - */ -bool bdev_check_media_change(struct block_device *bdev) -{ - unsigned int events; - - events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE | - DISK_EVENT_EJECT_REQUEST); - if (!(events & DISK_EVENT_MEDIA_CHANGE)) - return false; - - if (__invalidate_device(bdev, true)) - pr_warn("VFS: busy inodes on changed media %s\n", - bdev->bd_disk->disk_name); - set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); - return true; -} -EXPORT_SYMBOL(bdev_check_media_change); - -/* - * Separate this part out so that a different pointer for clearing_ptr can be - * passed in for disk_clear_events. - */ -static void disk_events_workfn(struct work_struct *work) -{ - struct delayed_work *dwork = to_delayed_work(work); - struct disk_events *ev = container_of(dwork, struct disk_events, dwork); - - disk_check_events(ev, &ev->clearing); -} - -static void disk_check_events(struct disk_events *ev, - unsigned int *clearing_ptr) -{ - struct gendisk *disk = ev->disk; - char *envp[ARRAY_SIZE(disk_uevents) + 1] = { }; - unsigned int clearing = *clearing_ptr; - unsigned int events; - unsigned long intv; - int nr_events = 0, i; - - /* check events */ - events = disk->fops->check_events(disk, clearing); - - /* accumulate pending events and schedule next poll if necessary */ - spin_lock_irq(&ev->lock); - - events &= ~ev->pending; - ev->pending |= events; - *clearing_ptr &= ~clearing; - - intv = disk_events_poll_jiffies(disk); - if (!ev->block && intv) - queue_delayed_work(system_freezable_power_efficient_wq, - &ev->dwork, intv); - - spin_unlock_irq(&ev->lock); - - /* - * Tell userland about new events. Only the events listed in - * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT - * is set. Otherwise, events are processed internally but never - * get reported to userland. - */ - for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) - if ((events & disk->events & (1 << i)) && - (disk->event_flags & DISK_EVENT_FLAG_UEVENT)) - envp[nr_events++] = disk_uevents[i]; - - if (nr_events) - kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); -} - -/* - * A disk events enabled device has the following sysfs nodes under - * its /sys/block/X/ directory. - * - * events : list of all supported events - * events_async : list of events which can be detected w/o polling - * (always empty, only for backwards compatibility) - * events_poll_msecs : polling interval, 0: disable, -1: system default - */ -static ssize_t __disk_events_show(unsigned int events, char *buf) -{ - const char *delim = ""; - ssize_t pos = 0; - int i; - - for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++) - if (events & (1 << i)) { - pos += sprintf(buf + pos, "%s%s", - delim, disk_events_strs[i]); - delim = " "; - } - if (pos) - pos += sprintf(buf + pos, "\n"); - return pos; -} - -static ssize_t disk_events_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct gendisk *disk = dev_to_disk(dev); - - if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT)) - return 0; - - return __disk_events_show(disk->events, buf); -} - -static ssize_t disk_events_async_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - return 0; -} - -static ssize_t disk_events_poll_msecs_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct gendisk *disk = dev_to_disk(dev); - - if (!disk->ev) - return sprintf(buf, "-1\n"); - - return sprintf(buf, "%ld\n", disk->ev->poll_msecs); -} - -static ssize_t disk_events_poll_msecs_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct gendisk *disk = dev_to_disk(dev); - long intv; - - if (!count || !sscanf(buf, "%ld", &intv)) - return -EINVAL; - - if (intv < 0 && intv != -1) - return -EINVAL; - - if (!disk->ev) - return -ENODEV; - - disk_block_events(disk); - disk->ev->poll_msecs = intv; - __disk_unblock_events(disk, true); - - return count; -} - -static const DEVICE_ATTR(events, 0444, disk_events_show, NULL); -static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL); -static const DEVICE_ATTR(events_poll_msecs, 0644, - disk_events_poll_msecs_show, - disk_events_poll_msecs_store); - -static const struct attribute *disk_events_attrs[] = { - &dev_attr_events.attr, - &dev_attr_events_async.attr, - &dev_attr_events_poll_msecs.attr, - NULL, -}; - -/* - * The default polling interval can be specified by the kernel - * parameter block.events_dfl_poll_msecs which defaults to 0 - * (disable). This can also be modified runtime by writing to - * /sys/module/block/parameters/events_dfl_poll_msecs. - */ -static int disk_events_set_dfl_poll_msecs(const char *val, - const struct kernel_param *kp) -{ - struct disk_events *ev; - int ret; - - ret = param_set_ulong(val, kp); - if (ret < 0) - return ret; - - mutex_lock(&disk_events_mutex); - - list_for_each_entry(ev, &disk_events, node) - disk_flush_events(ev->disk, 0); - - mutex_unlock(&disk_events_mutex); - - return 0; -} - -static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = { - .set = disk_events_set_dfl_poll_msecs, - .get = param_get_ulong, -}; - -#undef MODULE_PARAM_PREFIX -#define MODULE_PARAM_PREFIX "block." - -module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, - &disk_events_dfl_poll_msecs, 0644); - -/* - * disk_{alloc|add|del|release}_events - initialize and destroy disk_events. - */ -static void disk_alloc_events(struct gendisk *disk) -{ - struct disk_events *ev; - - if (!disk->fops->check_events || !disk->events) - return; - - ev = kzalloc(sizeof(*ev), GFP_KERNEL); - if (!ev) { - pr_warn("%s: failed to initialize events\n", disk->disk_name); - return; - } - - INIT_LIST_HEAD(&ev->node); - ev->disk = disk; - spin_lock_init(&ev->lock); - mutex_init(&ev->block_mutex); - ev->block = 1; - ev->poll_msecs = -1; - INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); - - disk->ev = ev; -} - -static void disk_add_events(struct gendisk *disk) -{ - /* FIXME: error handling */ - if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0) - pr_warn("%s: failed to create sysfs files for events\n", - disk->disk_name); - - if (!disk->ev) - return; - - mutex_lock(&disk_events_mutex); - list_add_tail(&disk->ev->node, &disk_events); - mutex_unlock(&disk_events_mutex); - - /* - * Block count is initialized to 1 and the following initial - * unblock kicks it into action. - */ - __disk_unblock_events(disk, true); -} - -static void disk_del_events(struct gendisk *disk) -{ - if (disk->ev) { - disk_block_events(disk); - - mutex_lock(&disk_events_mutex); - list_del_init(&disk->ev->node); - mutex_unlock(&disk_events_mutex); - } - - sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); -} - -static void disk_release_events(struct gendisk *disk) -{ - /* the block count should be 1 from disk_del_events() */ - WARN_ON_ONCE(disk->ev && disk->ev->block != 1); - kfree(disk->ev); -} |