diff options
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/Kconfig | 13 | ||||
-rw-r--r-- | drivers/block/brd.c | 137 | ||||
-rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 2 | ||||
-rw-r--r-- | drivers/block/floppy.c | 17 | ||||
-rw-r--r-- | drivers/block/loop.c | 416 | ||||
-rw-r--r-- | drivers/block/loop.h | 18 | ||||
-rw-r--r-- | drivers/block/null_blk.c | 2 | ||||
-rw-r--r-- | drivers/block/nvme-core.c | 128 | ||||
-rw-r--r-- | drivers/block/osdblk.c | 2 | ||||
-rw-r--r-- | drivers/block/virtio_blk.c | 12 | ||||
-rw-r--r-- | drivers/block/xen-blkback/blkback.c | 177 | ||||
-rw-r--r-- | drivers/block/xen-blkback/common.h | 12 | ||||
-rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 4 | ||||
-rw-r--r-- | drivers/block/xen-blkfront.c | 6 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.c | 227 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.h | 21 |
16 files changed, 664 insertions, 530 deletions
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 014a1cfc41c5..1b8094d4d7af 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -393,14 +393,15 @@ config BLK_DEV_RAM_SIZE The default value is 4096 kilobytes. Only change this if you know what you are doing. -config BLK_DEV_XIP - bool "Support XIP filesystems on RAM block device" - depends on BLK_DEV_RAM +config BLK_DEV_RAM_DAX + bool "Support Direct Access (DAX) to RAM block devices" + depends on BLK_DEV_RAM && FS_DAX default n help - Support XIP filesystems (such as ext2 with XIP support on) on - top of block ram device. This will slightly enlarge the kernel, and - will prevent RAM block device backing store memory from being + Support filesystems using DAX to access RAM block devices. This + avoids double-buffering data in the page cache before copying it + to the block device. Answering Y will slightly enlarge the kernel, + and will prevent RAM block device backing store memory from being allocated from highmem (only a problem for highmem systems). config CDROM_PKTCDVD diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 3598110d2cef..64ab4951e9d6 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -97,13 +97,13 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector) * Must use NOIO because we don't want to recurse back into the * block or filesystem layers from page reclaim. * - * Cannot support XIP and highmem, because our ->direct_access - * routine for XIP must return memory that is always addressable. - * If XIP was reworked to use pfns and kmap throughout, this + * Cannot support DAX and highmem, because our ->direct_access + * routine for DAX must return memory that is always addressable. + * If DAX was reworked to use pfns and kmap throughout, this * restriction might be able to be lifted. */ gfp_flags = GFP_NOIO | __GFP_ZERO; -#ifndef CONFIG_BLK_DEV_XIP +#ifndef CONFIG_BLK_DEV_RAM_DAX gfp_flags |= __GFP_HIGHMEM; #endif page = alloc_page(gfp_flags); @@ -369,27 +369,29 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, return err; } -#ifdef CONFIG_BLK_DEV_XIP -static int brd_direct_access(struct block_device *bdev, sector_t sector, - void **kaddr, unsigned long *pfn) +#ifdef CONFIG_BLK_DEV_RAM_DAX +static long brd_direct_access(struct block_device *bdev, sector_t sector, + void **kaddr, unsigned long *pfn, long size) { struct brd_device *brd = bdev->bd_disk->private_data; struct page *page; if (!brd) return -ENODEV; - if (sector & (PAGE_SECTORS-1)) - return -EINVAL; - if (sector + PAGE_SECTORS > get_capacity(bdev->bd_disk)) - return -ERANGE; page = brd_insert_page(brd, sector); if (!page) return -ENOSPC; *kaddr = page_address(page); *pfn = page_to_pfn(page); - return 0; + /* + * TODO: If size > PAGE_SIZE, we could look to see if the next page in + * the file happens to be mapped to the next page of physical RAM. + */ + return PAGE_SIZE; } +#else +#define brd_direct_access NULL #endif static int brd_ioctl(struct block_device *bdev, fmode_t mode, @@ -430,27 +432,24 @@ static const struct block_device_operations brd_fops = { .owner = THIS_MODULE, .rw_page = brd_rw_page, .ioctl = brd_ioctl, -#ifdef CONFIG_BLK_DEV_XIP .direct_access = brd_direct_access, -#endif }; /* * And now the modules code and kernel interface. */ -static int rd_nr; -int rd_size = CONFIG_BLK_DEV_RAM_SIZE; -static int max_part; -static int part_shift; -static int part_show = 0; +static int rd_nr = CONFIG_BLK_DEV_RAM_COUNT; module_param(rd_nr, int, S_IRUGO); MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices"); + +int rd_size = CONFIG_BLK_DEV_RAM_SIZE; module_param(rd_size, int, S_IRUGO); MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes."); + +static int max_part = 1; module_param(max_part, int, S_IRUGO); -MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk"); -module_param(part_show, int, S_IRUGO); -MODULE_PARM_DESC(part_show, "Control RAM disk visibility in /proc/partitions"); +MODULE_PARM_DESC(max_part, "Num Minors to reserve between devices"); + MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR); MODULE_ALIAS("rd"); @@ -487,25 +486,33 @@ static struct brd_device *brd_alloc(int i) brd->brd_queue = blk_alloc_queue(GFP_KERNEL); if (!brd->brd_queue) goto out_free_dev; + blk_queue_make_request(brd->brd_queue, brd_make_request); blk_queue_max_hw_sectors(brd->brd_queue, 1024); blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY); + /* This is so fdisk will align partitions on 4k, because of + * direct_access API needing 4k alignment, returning a PFN + * (This is only a problem on very small devices <= 4M, + * otherwise fdisk will align on 1M. Regardless this call + * is harmless) + */ + blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE); + brd->brd_queue->limits.discard_granularity = PAGE_SIZE; brd->brd_queue->limits.max_discard_sectors = UINT_MAX; brd->brd_queue->limits.discard_zeroes_data = 1; queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, brd->brd_queue); - disk = brd->brd_disk = alloc_disk(1 << part_shift); + disk = brd->brd_disk = alloc_disk(max_part); if (!disk) goto out_free_queue; disk->major = RAMDISK_MAJOR; - disk->first_minor = i << part_shift; + disk->first_minor = i * max_part; disk->fops = &brd_fops; disk->private_data = brd; disk->queue = brd->brd_queue; - if (!part_show) - disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; + disk->flags = GENHD_FL_EXT_DEVT; sprintf(disk->disk_name, "ram%d", i); set_capacity(disk, rd_size * 2); @@ -527,10 +534,11 @@ static void brd_free(struct brd_device *brd) kfree(brd); } -static struct brd_device *brd_init_one(int i) +static struct brd_device *brd_init_one(int i, bool *new) { struct brd_device *brd; + *new = false; list_for_each_entry(brd, &brd_devices, brd_list) { if (brd->brd_number == i) goto out; @@ -541,6 +549,7 @@ static struct brd_device *brd_init_one(int i) add_disk(brd->brd_disk); list_add_tail(&brd->brd_list, &brd_devices); } + *new = true; out: return brd; } @@ -556,70 +565,46 @@ static struct kobject *brd_probe(dev_t dev, int *part, void *data) { struct brd_device *brd; struct kobject *kobj; + bool new; mutex_lock(&brd_devices_mutex); - brd = brd_init_one(MINOR(dev) >> part_shift); + brd = brd_init_one(MINOR(dev) / max_part, &new); kobj = brd ? get_disk(brd->brd_disk) : NULL; mutex_unlock(&brd_devices_mutex); - *part = 0; + if (new) + *part = 0; + return kobj; } static int __init brd_init(void) { - int i, nr; - unsigned long range; struct brd_device *brd, *next; + int i; /* * brd module now has a feature to instantiate underlying device * structure on-demand, provided that there is an access dev node. - * However, this will not work well with user space tool that doesn't - * know about such "feature". In order to not break any existing - * tool, we do the following: * - * (1) if rd_nr is specified, create that many upfront, and this - * also becomes a hard limit. - * (2) if rd_nr is not specified, create CONFIG_BLK_DEV_RAM_COUNT - * (default 16) rd device on module load, user can further - * extend brd device by create dev node themselves and have - * kernel automatically instantiate actual device on-demand. + * (1) if rd_nr is specified, create that many upfront. else + * it defaults to CONFIG_BLK_DEV_RAM_COUNT + * (2) User can further extend brd devices by create dev node themselves + * and have kernel automatically instantiate actual device + * on-demand. Example: + * mknod /path/devnod_name b 1 X # 1 is the rd major + * fdisk -l /path/devnod_name + * If (X / max_part) was not already created it will be created + * dynamically. */ - part_shift = 0; - if (max_part > 0) { - part_shift = fls(max_part); - - /* - * Adjust max_part according to part_shift as it is exported - * to user space so that user can decide correct minor number - * if [s]he want to create more devices. - * - * Note that -1 is required because partition 0 is reserved - * for the whole disk. - */ - max_part = (1UL << part_shift) - 1; - } - - if ((1UL << part_shift) > DISK_MAX_PARTS) - return -EINVAL; - - if (rd_nr > 1UL << (MINORBITS - part_shift)) - return -EINVAL; - - if (rd_nr) { - nr = rd_nr; - range = rd_nr << part_shift; - } else { - nr = CONFIG_BLK_DEV_RAM_COUNT; - range = 1UL << MINORBITS; - } - if (register_blkdev(RAMDISK_MAJOR, "ramdisk")) return -EIO; - for (i = 0; i < nr; i++) { + if (unlikely(!max_part)) + max_part = 1; + + for (i = 0; i < rd_nr; i++) { brd = brd_alloc(i); if (!brd) goto out_free; @@ -631,10 +616,10 @@ static int __init brd_init(void) list_for_each_entry(brd, &brd_devices, brd_list) add_disk(brd->brd_disk); - blk_register_region(MKDEV(RAMDISK_MAJOR, 0), range, + blk_register_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS, THIS_MODULE, brd_probe, NULL, NULL); - printk(KERN_INFO "brd: module loaded\n"); + pr_info("brd: module loaded\n"); return 0; out_free: @@ -644,21 +629,21 @@ out_free: } unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); + pr_info("brd: module NOT loaded !!!\n"); return -ENOMEM; } static void __exit brd_exit(void) { - unsigned long range; struct brd_device *brd, *next; - range = rd_nr ? rd_nr << part_shift : 1UL << MINORBITS; - list_for_each_entry_safe(brd, next, &brd_devices, brd_list) brd_del_one(brd); - blk_unregister_region(MKDEV(RAMDISK_MAJOR, 0), range); + blk_unregister_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS); unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); + + pr_info("brd: module unloaded\n"); } module_init(brd_init); diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index d169b4a79267..cee20354ac37 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1388,7 +1388,7 @@ int drbd_submit_peer_request(struct drbd_device *device, list_add_tail(&peer_req->w.list, &device->active_ee); spin_unlock_irq(&device->resource->req_lock); if (blkdev_issue_zeroout(device->ldev->backing_bdev, - sector, data_size >> 9, GFP_NOIO)) + sector, data_size >> 9, GFP_NOIO, false)) peer_req->flags |= EE_WAS_ERROR; drbd_endio_write_sec_final(peer_req); return 0; diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 56d46ffb08e1..a08cda955285 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4112,6 +4112,13 @@ static ssize_t floppy_cmos_show(struct device *dev, static DEVICE_ATTR(cmos, S_IRUGO, floppy_cmos_show, NULL); +static struct attribute *floppy_dev_attrs[] = { + &dev_attr_cmos.attr, + NULL +}; + +ATTRIBUTE_GROUPS(floppy_dev); + static void floppy_device_release(struct device *dev) { } @@ -4324,16 +4331,12 @@ static int __init do_floppy_init(void) floppy_device[drive].name = floppy_device_name; floppy_device[drive].id = drive; floppy_device[drive].dev.release = floppy_device_release; + floppy_device[drive].dev.groups = floppy_dev_groups; err = platform_device_register(&floppy_device[drive]); if (err) goto out_remove_drives; - err = device_create_file(&floppy_device[drive].dev, - &dev_attr_cmos); - if (err) - goto out_unreg_platform_dev; - /* to be cleaned up... */ disks[drive]->private_data = (void *)(long)drive; disks[drive]->flags |= GENHD_FL_REMOVABLE; @@ -4343,13 +4346,10 @@ static int __init do_floppy_init(void) return 0; -out_unreg_platform_dev: - platform_device_unregister(&floppy_device[drive]); out_remove_drives: while (drive--) { if (floppy_available(drive)) { del_gendisk(disks[drive]); - device_remove_file(&floppy_device[drive].dev, &dev_attr_cmos); platform_device_unregister(&floppy_device[drive]); } } @@ -4594,7 +4594,6 @@ static void __exit floppy_module_exit(void) if (floppy_available(drive)) { del_gendisk(disks[drive]); - device_remove_file(&floppy_device[drive].dev, &dev_attr_cmos); platform_device_unregister(&floppy_device[drive]); } blk_cleanup_queue(disks[drive]->queue); diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 6cb1beb47c25..d1f168b73634 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -85,6 +85,8 @@ static DEFINE_MUTEX(loop_index_mutex); static int max_part; static int part_shift; +static struct workqueue_struct *loop_wq; + /* * Transfer functions */ @@ -284,12 +286,12 @@ static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, return ret; } -static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) +static int lo_send(struct loop_device *lo, struct request *rq, loff_t pos) { int (*do_lo_send)(struct loop_device *, struct bio_vec *, loff_t, struct page *page); struct bio_vec bvec; - struct bvec_iter iter; + struct req_iterator iter; struct page *page = NULL; int ret = 0; @@ -303,7 +305,7 @@ static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) do_lo_send = do_lo_send_direct_write; } - bio_for_each_segment(bvec, bio, iter) { + rq_for_each_segment(bvec, rq, iter) { ret = do_lo_send(lo, &bvec, pos, page); if (ret < 0) break; @@ -391,19 +393,22 @@ do_lo_receive(struct loop_device *lo, } static int -lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos) +lo_receive(struct loop_device *lo, struct request *rq, int bsize, loff_t pos) { struct bio_vec bvec; - struct bvec_iter iter; + struct req_iterator iter; ssize_t s; - bio_for_each_segment(bvec, bio, iter) { + rq_for_each_segment(bvec, rq, iter) { s = do_lo_receive(lo, &bvec, bsize, pos); if (s < 0) return s; if (s != bvec.bv_len) { - zero_fill_bio(bio); + struct bio *bio; + + __rq_for_each_bio(bio, rq) + zero_fill_bio(bio); break; } pos += bvec.bv_len; @@ -411,106 +416,58 @@ lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos) return 0; } -static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) +static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos) { - loff_t pos; + /* + * We use punch hole to reclaim the free space used by the + * image a.k.a. discard. However we do not support discard if + * encryption is enabled, because it may give an attacker + * useful information. + */ + struct file *file = lo->lo_backing_file; + int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; int ret; - pos = ((loff_t) bio->bi_iter.bi_sector << 9) + lo->lo_offset; - - if (bio_rw(bio) == WRITE) { - struct file *file = lo->lo_backing_file; - - if (bio->bi_rw & REQ_FLUSH) { - ret = vfs_fsync(file, 0); - if (unlikely(ret && ret != -EINVAL)) { - ret = -EIO; - goto out; - } - } - - /* - * We use punch hole to reclaim the free space used by the - * image a.k.a. discard. However we do not support discard if - * encryption is enabled, because it may give an attacker - * useful information. - */ - if (bio->bi_rw & REQ_DISCARD) { - struct file *file = lo->lo_backing_file; - int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; - - if ((!file->f_op->fallocate) || - lo->lo_encrypt_key_size) { - ret = -EOPNOTSUPP; - goto out; - } - ret = file->f_op->fallocate(file, mode, pos, - bio->bi_iter.bi_size); - if (unlikely(ret && ret != -EINVAL && - ret != -EOPNOTSUPP)) - ret = -EIO; - goto out; - } - - ret = lo_send(lo, bio, pos); - - if ((bio->bi_rw & REQ_FUA) && !ret) { - ret = vfs_fsync(file, 0); - if (unlikely(ret && ret != -EINVAL)) - ret = -EIO; - } - } else - ret = lo_receive(lo, bio, lo->lo_blocksize, pos); + if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) { + ret = -EOPNOTSUPP; + goto out; + } -out: + ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); + if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) + ret = -EIO; + out: return ret; } -/* - * Add bio to back of pending list - */ -static void loop_add_bio(struct loop_device *lo, struct bio *bio) +static int lo_req_flush(struct loop_device *lo, struct request *rq) { - lo->lo_bio_count++; - bio_list_add(&lo->lo_bio_list, bio); -} + struct file *file = lo->lo_backing_file; + int ret = vfs_fsync(file, 0); + if (unlikely(ret && ret != -EINVAL)) + ret = -EIO; -/* - * Grab first pending buffer - */ -static struct bio *loop_get_bio(struct loop_device *lo) -{ - lo->lo_bio_count--; - return bio_list_pop(&lo->lo_bio_list); + return ret; } -static void loop_make_request(struct request_queue *q, struct bio *old_bio) +static int do_req_filebacked(struct loop_device *lo, struct request *rq) { - struct loop_device *lo = q->queuedata; - int rw = bio_rw(old_bio); - - if (rw == READA) - rw = READ; + loff_t pos; + int ret; - BUG_ON(!lo || (rw != READ && rw != WRITE)); + pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; - spin_lock_irq(&lo->lo_lock); - if (lo->lo_state != Lo_bound) - goto out; - if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY))) - goto out; - if (lo->lo_bio_count >= q->nr_congestion_on) - wait_event_lock_irq(lo->lo_req_wait, - lo->lo_bio_count < q->nr_congestion_off, - lo->lo_lock); - loop_add_bio(lo, old_bio); - wake_up(&lo->lo_event); - spin_unlock_irq(&lo->lo_lock); - return; + if (rq->cmd_flags & REQ_WRITE) { + if (rq->cmd_flags & REQ_FLUSH) + ret = lo_req_flush(lo, rq); + else if (rq->cmd_flags & REQ_DISCARD) + ret = lo_discard(lo, rq, pos); + else + ret = lo_send(lo, rq, pos); + } else + ret = lo_receive(lo, rq, lo->lo_blocksize, pos); -out: - spin_unlock_irq(&lo->lo_lock); - bio_io_error(old_bio); + return ret; } struct switch_request { @@ -518,57 +475,26 @@ struct switch_request { struct completion wait; }; -static void do_loop_switch(struct loop_device *, struct switch_request *); - -static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) -{ - if (unlikely(!bio->bi_bdev)) { - do_loop_switch(lo, bio->bi_private); - bio_put(bio); - } else { - int ret = do_bio_filebacked(lo, bio); - bio_endio(bio, ret); - } -} - /* - * worker thread that handles reads/writes to file backed loop devices, - * to avoid blocking in our make_request_fn. it also does loop decrypting - * on reads for block backed loop, as that is too heavy to do from - * b_end_io context where irqs may be disabled. - * - * Loop explanation: loop_clr_fd() sets lo_state to Lo_rundown before - * calling kthread_stop(). Therefore once kthread_should_stop() is - * true, make_request will not place any more requests. Therefore - * once kthread_should_stop() is true and lo_bio is NULL, we are - * done with the loop. + * Do the actual switch; called from the BIO completion routine */ -static int loop_thread(void *data) +static void do_loop_switch(struct loop_device *lo, struct switch_request *p) { - struct loop_device *lo = data; - struct bio *bio; - - set_user_nice(current, MIN_NICE); - - while (!kthread_should_stop() || !bio_list_empty(&lo->lo_bio_list)) { - - wait_event_interruptible(lo->lo_event, - !bio_list_empty(&lo->lo_bio_list) || - kthread_should_stop()); - - if (bio_list_empty(&lo->lo_bio_list)) - continue; - spin_lock_irq(&lo->lo_lock); - bio = loop_get_bio(lo); - if (lo->lo_bio_count < lo->lo_queue->nr_congestion_off) - wake_up(&lo->lo_req_wait); - spin_unlock_irq(&lo->lo_lock); + struct file *file = p->file; + struct file *old_file = lo->lo_backing_file; + struct address_space *mapping; - BUG_ON(!bio); - loop_handle_bio(lo, bio); - } + /* if no new file, only flush of queued bios requested */ + if (!file) + return; - return 0; + mapping = file->f_mapping; + mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); + lo->lo_backing_file = file; + lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? + mapping->host->i_bdev->bd_block_size : PAGE_SIZE; + lo->old_gfp_mask = mapping_gfp_mask(mapping); + mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); } /* @@ -579,15 +505,18 @@ static int loop_thread(void *data) static int loop_switch(struct loop_device *lo, struct file *file) { struct switch_request w; - struct bio *bio = bio_alloc(GFP_KERNEL, 0); - if (!bio) - return -ENOMEM; - init_completion(&w.wait); + w.file = file; - bio->bi_private = &w; - bio->bi_bdev = NULL; - loop_make_request(lo->lo_queue, bio); - wait_for_completion(&w.wait); + + /* freeze queue and wait for completion of scheduled requests */ + blk_mq_freeze_queue(lo->lo_queue); + + /* do the switch action */ + do_loop_switch(lo, &w); + + /* unfreeze */ + blk_mq_unfreeze_queue(lo->lo_queue); + return 0; } @@ -596,39 +525,10 @@ static int loop_switch(struct loop_device *lo, struct file *file) */ static int loop_flush(struct loop_device *lo) { - /* loop not yet configured, no running thread, nothing to flush */ - if (!lo->lo_thread) - return 0; - return loop_switch(lo, NULL); } /* - * Do the actual switch; called from the BIO completion routine - */ -static void do_loop_switch(struct loop_device *lo, struct switch_request *p) -{ - struct file *file = p->file; - struct file *old_file = lo->lo_backing_file; - struct address_space *mapping; - - /* if no new file, only flush of queued bios requested */ - if (!file) - goto out; - - mapping = file->f_mapping; - mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); - lo->lo_backing_file = file; - lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? - mapping->host->i_bdev->bd_block_size : PAGE_SIZE; - lo->old_gfp_mask = mapping_gfp_mask(mapping); - mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); -out: - complete(&p->wait); -} - - -/* * loop_change_fd switched the backing store of a loopback device to * a new file. This is useful for operating system installers to free up * the original file and in High Availability environments to switch to @@ -889,12 +789,9 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, lo->transfer = transfer_none; lo->ioctl = NULL; lo->lo_sizelimit = 0; - lo->lo_bio_count = 0; lo->old_gfp_mask = mapping_gfp_mask(mapping); mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - bio_list_init(&lo->lo_bio_list); - if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) blk_queue_flush(lo->lo_queue, REQ_FLUSH); @@ -906,14 +803,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, set_blocksize(bdev, lo_blocksize); - lo->lo_thread = kthread_create(loop_thread, lo, "loop%d", - lo->lo_number); - if (IS_ERR(lo->lo_thread)) { - error = PTR_ERR(lo->lo_thread); - goto out_clr; - } lo->lo_state = Lo_bound; - wake_up_process(lo->lo_thread); if (part_shift) lo->lo_flags |= LO_FLAGS_PARTSCAN; if (lo->lo_flags & LO_FLAGS_PARTSCAN) @@ -925,18 +815,6 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, bdgrab(bdev); return 0; -out_clr: - loop_sysfs_exit(lo); - lo->lo_thread = NULL; - lo->lo_device = NULL; - lo->lo_backing_file = NULL; - lo->lo_flags = 0; - set_capacity(lo->lo_disk, 0); - invalidate_bdev(bdev); - bd_set_size(bdev, 0); - kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); - mapping_set_gfp_mask(mapping, lo->old_gfp_mask); - lo->lo_state = Lo_unbound; out_putf: fput(file); out: @@ -1012,11 +890,6 @@ static int loop_clr_fd(struct loop_device *lo) spin_lock_irq(&lo->lo_lock); lo->lo_state = Lo_rundown; - spin_unlock_irq(&lo->lo_lock); - - kthread_stop(lo->lo_thread); - - spin_lock_irq(&lo->lo_lock); lo->lo_backing_file = NULL; spin_unlock_irq(&lo->lo_lock); @@ -1028,7 +901,6 @@ static int loop_clr_fd(struct loop_device *lo) lo->lo_offset = 0; lo->lo_sizelimit = 0; lo->lo_encrypt_key_size = 0; - lo->lo_thread = NULL; memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); memset(lo->lo_file_name, 0, LO_NAME_SIZE); @@ -1601,6 +1473,105 @@ int loop_unregister_transfer(int number) EXPORT_SYMBOL(loop_register_transfer); EXPORT_SYMBOL(loop_unregister_transfer); +static int loop_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); + + blk_mq_start_request(bd->rq); + + if (cmd->rq->cmd_flags & REQ_WRITE) { + struct loop_device *lo = cmd->rq->q->queuedata; + bool need_sched = true; + + spin_lock_irq(&lo->lo_lock); + if (lo->write_started) + need_sched = false; + else + lo->write_started = true; + list_add_tail(&cmd->list, &lo->write_cmd_head); + spin_unlock_irq(&lo->lo_lock); + + if (need_sched) + queue_work(loop_wq, &lo->write_work); + } else { + queue_work(loop_wq, &cmd->read_work); + } + + return BLK_MQ_RQ_QUEUE_OK; +} + +static void loop_handle_cmd(struct loop_cmd *cmd) +{ + const bool write = cmd->rq->cmd_flags & REQ_WRITE; + struct loop_device *lo = cmd->rq->q->queuedata; + int ret = -EIO; + + if (lo->lo_state != Lo_bound) + goto failed; + + if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) + goto failed; + + ret = do_req_filebacked(lo, cmd->rq); + + failed: + if (ret) + cmd->rq->errors = -EIO; + blk_mq_complete_request(cmd->rq); +} + +static void loop_queue_write_work(struct work_struct *work) +{ + struct loop_device *lo = + container_of(work, struct loop_device, write_work); + LIST_HEAD(cmd_list); + + spin_lock_irq(&lo->lo_lock); + repeat: + list_splice_init(&lo->write_cmd_head, &cmd_list); + spin_unlock_irq(&lo->lo_lock); + + while (!list_empty(&cmd_list)) { + struct loop_cmd *cmd = list_first_entry(&cmd_list, + struct loop_cmd, list); + list_del_init(&cmd->list); + loop_handle_cmd(cmd); + } + + spin_lock_irq(&lo->lo_lock); + if (!list_empty(&lo->write_cmd_head)) + goto repeat; + lo->write_started = false; + spin_unlock_irq(&lo->lo_lock); +} + +static void loop_queue_read_work(struct work_struct *work) +{ + struct loop_cmd *cmd = + container_of(work, struct loop_cmd, read_work); + + loop_handle_cmd(cmd); +} + +static int loop_init_request(void *data, struct request *rq, + unsigned int hctx_idx, unsigned int request_idx, + unsigned int numa_node) +{ + struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); + + cmd->rq = rq; + INIT_WORK(&cmd->read_work, loop_queue_read_work); + + return 0; +} + +static struct blk_mq_ops loop_mq_ops = { + .queue_rq = loop_queue_rq, + .map_queue = blk_mq_map_queue, + .init_request = loop_init_request, +}; + static int loop_add(struct loop_device **l, int i) { struct loop_device *lo; @@ -1627,16 +1598,28 @@ static int loop_add(struct loop_device **l, int i) i = err; err = -ENOMEM; - lo->lo_queue = blk_alloc_queue(GFP_KERNEL); - if (!lo->lo_queue) + lo->tag_set.ops = &loop_mq_ops; + lo->tag_set.nr_hw_queues = 1; + lo->tag_set.queue_depth = 128; + lo->tag_set.numa_node = NUMA_NO_NODE; + lo->tag_set.cmd_size = sizeof(struct loop_cmd); + lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; + lo->tag_set.driver_data = lo; + + err = blk_mq_alloc_tag_set(&lo->tag_set); + if (err) goto out_free_idr; - /* - * set queue make_request_fn - */ - blk_queue_make_request(lo->lo_queue, loop_make_request); + lo->lo_queue = blk_mq_init_queue(&lo->tag_set); + if (IS_ERR_OR_NULL(lo->lo_queue)) { + err = PTR_ERR(lo->lo_queue); + goto out_cleanup_tags; + } lo->lo_queue->queuedata = lo; + INIT_LIST_HEAD(&lo->write_cmd_head); + INIT_WORK(&lo->write_work, loop_queue_write_work); + disk = lo->lo_disk = alloc_disk(1 << part_shift); if (!disk) goto out_free_queue; @@ -1664,9 +1647,6 @@ static int loop_add(struct loop_device **l, int i) disk->flags |= GENHD_FL_EXT_DEVT; mutex_init(&lo->lo_ctl_mutex); lo->lo_number = i; - lo->lo_thread = NULL; - init_waitqueue_head(&lo->lo_event); - init_waitqueue_head(&lo->lo_req_wait); spin_lock_init(&lo->lo_lock); disk->major = LOOP_MAJOR; disk->first_minor = i << part_shift; @@ -1680,6 +1660,8 @@ static int loop_add(struct loop_device **l, int i) out_free_queue: blk_cleanup_queue(lo->lo_queue); +out_cleanup_tags: + blk_mq_free_tag_set(&lo->tag_set); out_free_idr: idr_remove(&loop_index_idr, i); out_free_dev: @@ -1692,6 +1674,7 @@ static void loop_remove(struct loop_device *lo) { del_gendisk(lo->lo_disk); blk_cleanup_queue(lo->lo_queue); + blk_mq_free_tag_set(&lo->tag_set); put_disk(lo->lo_disk); kfree(lo); } @@ -1875,6 +1858,13 @@ static int __init loop_init(void) goto misc_out; } + loop_wq = alloc_workqueue("kloopd", + WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0); + if (!loop_wq) { + err = -ENOMEM; + goto misc_out; + } + blk_register_region(MKDEV(LOOP_MAJOR, 0), range, THIS_MODULE, loop_probe, NULL, NULL); @@ -1912,6 +1902,8 @@ static void __exit loop_exit(void) blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); unregister_blkdev(LOOP_MAJOR, "loop"); + destroy_workqueue(loop_wq); + misc_deregister(&loop_misc); } diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 90df5d6485b6..301c27f8323f 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -11,8 +11,10 @@ #include <linux/bio.h> #include <linux/blkdev.h> +#include <linux/blk-mq.h> #include <linux/spinlock.h> #include <linux/mutex.h> +#include <linux/workqueue.h> #include <uapi/linux/loop.h> /* Possible states of device */ @@ -52,19 +54,23 @@ struct loop_device { gfp_t old_gfp_mask; spinlock_t lo_lock; - struct bio_list lo_bio_list; - unsigned int lo_bio_count; + struct list_head write_cmd_head; + struct work_struct write_work; + bool write_started; int lo_state; struct mutex lo_ctl_mutex; - struct task_struct *lo_thread; - wait_queue_head_t lo_event; - /* wait queue for incoming requests */ - wait_queue_head_t lo_req_wait; struct request_queue *lo_queue; + struct blk_mq_tag_set tag_set; struct gendisk *lo_disk; }; +struct loop_cmd { + struct work_struct read_work; + struct request *rq; + struct list_head list; +}; + /* Support for loadable transfer modules */ struct loop_func_table { int number; /* filter type */ diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index aa2224aa7caa..65cd61a4145e 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -579,7 +579,7 @@ static int null_add_dev(void) sector_div(size, bs); set_capacity(disk, size); - disk->flags |= GENHD_FL_EXT_DEVT; + disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO; disk->major = null_major; disk->first_minor = nullb->index; disk->fops = &null_fops; diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index d826bf3e62c8..cbdfbbf98392 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -144,8 +144,37 @@ struct nvme_cmd_info { void *ctx; int aborted; struct nvme_queue *nvmeq; + struct nvme_iod iod[0]; }; +/* + * Max size of iod being embedded in the request payload + */ +#define NVME_INT_PAGES 2 +#define NVME_INT_BYTES(dev) (NVME_INT_PAGES * (dev)->page_size) + +/* + * Will slightly overestimate the number of pages needed. This is OK + * as it only leads to a small amount of wasted memory for the lifetime of + * the I/O. + */ +static int nvme_npages(unsigned size, struct nvme_dev *dev) +{ + unsigned nprps = DIV_ROUND_UP(size + dev->page_size, dev->page_size); + return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8); +} + +static unsigned int nvme_cmd_size(struct nvme_dev *dev) +{ + unsigned int ret = sizeof(struct nvme_cmd_info); + + ret += sizeof(struct nvme_iod); + ret += sizeof(__le64 *) * nvme_npages(NVME_INT_BYTES(dev), dev); + ret += sizeof(struct scatterlist) * NVME_INT_PAGES; + + return ret; +} + static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, unsigned int hctx_idx) { @@ -218,6 +247,19 @@ static void nvme_set_info(struct nvme_cmd_info *cmd, void *ctx, blk_mq_start_request(blk_mq_rq_from_pdu(cmd)); } +static void *iod_get_private(struct nvme_iod *iod) +{ + return (void *) (iod->private & ~0x1UL); +} + +/* + * If bit 0 is set, the iod is embedded in the request payload. + */ +static bool iod_should_kfree(struct nvme_iod *iod) +{ + return (iod->private & 0x01) == 0; +} + /* Special values must be less than 0x1000 */ #define CMD_CTX_BASE ((void *)POISON_POINTER_DELTA) #define CMD_CTX_CANCELLED (0x30C + CMD_CTX_BASE) @@ -361,35 +403,53 @@ static __le64 **iod_list(struct nvme_iod *iod) return ((void *)iod) + iod->offset; } -/* - * Will slightly overestimate the number of pages needed. This is OK - * as it only leads to a small amount of wasted memory for the lifetime of - * the I/O. - */ -static int nvme_npages(unsigned size, struct nvme_dev *dev) +static inline void iod_init(struct nvme_iod *iod, unsigned nbytes, + unsigned nseg, unsigned long private) { - unsigned nprps = DIV_ROUND_UP(size + dev->page_size, dev->page_size); - return DIV_ROUND_UP(8 * nprps, dev->page_size - 8); + iod->private = private; + iod->offset = offsetof(struct nvme_iod, sg[nseg]); + iod->npages = -1; + iod->length = nbytes; + iod->nents = 0; } static struct nvme_iod * -nvme_alloc_iod(unsigned nseg, unsigned nbytes, struct nvme_dev *dev, gfp_t gfp) +__nvme_alloc_iod(unsigned nseg, unsigned bytes, struct nvme_dev *dev, + unsigned long priv, gfp_t gfp) { struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) + - sizeof(__le64 *) * nvme_npages(nbytes, dev) + + sizeof(__le64 *) * nvme_npages(bytes, dev) + sizeof(struct scatterlist) * nseg, gfp); - if (iod) { - iod->offset = offsetof(struct nvme_iod, sg[nseg]); - iod->npages = -1; - iod->length = nbytes; - iod->nents = 0; - iod->first_dma = 0ULL; - } + if (iod) + iod_init(iod, bytes, nseg, priv); return iod; } +static struct nvme_iod *nvme_alloc_iod(struct request *rq, struct nvme_dev *dev, + gfp_t gfp) +{ + unsigned size = !(rq->cmd_flags & REQ_DISCARD) ? blk_rq_bytes(rq) : + sizeof(struct nvme_dsm_range); + unsigned long mask = 0; + struct nvme_iod *iod; + + if (rq->nr_phys_segments <= NVME_INT_PAGES && + size <= NVME_INT_BYTES(dev)) { + struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(rq); + + iod = cmd->iod; + mask = 0x01; + iod_init(iod, size, rq->nr_phys_segments, + (unsigned long) rq | 0x01); + return iod; + } + + return __nvme_alloc_iod(rq->nr_phys_segments, size, dev, + (unsigned long) rq, gfp); +} + void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod) { const int last_prp = dev->page_size / 8 - 1; @@ -405,7 +465,9 @@ void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod) dma_pool_free(dev->prp_page_pool, prp_list, prp_dma); prp_dma = next_prp_dma; } - kfree(iod); + + if (iod_should_kfree(iod)) + kfree(iod); } static int nvme_error_status(u16 status) @@ -424,7 +486,7 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, struct nvme_completion *cqe) { struct nvme_iod *iod = ctx; - struct request *req = iod->private; + struct request *req = iod_get_private(iod); struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req); u16 status = le16_to_cpup(&cqe->status) >> 1; @@ -585,7 +647,7 @@ static void nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns, static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod, struct nvme_ns *ns) { - struct request *req = iod->private; + struct request *req = iod_get_private(iod); struct nvme_command *cmnd; u16 control = 0; u32 dsmgmt = 0; @@ -626,17 +688,12 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req = bd->rq; struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req); struct nvme_iod *iod; - int psegs = req->nr_phys_segments; enum dma_data_direction dma_dir; - unsigned size = !(req->cmd_flags & REQ_DISCARD) ? blk_rq_bytes(req) : - sizeof(struct nvme_dsm_range); - iod = nvme_alloc_iod(psegs, size, ns->dev, GFP_ATOMIC); + iod = nvme_alloc_iod(req, ns->dev, GFP_ATOMIC); if (!iod) return BLK_MQ_RQ_QUEUE_BUSY; - iod->private = req; - if (req->cmd_flags & REQ_DISCARD) { void *range; /* @@ -651,10 +708,10 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx, goto retry_cmd; iod_list(iod)[0] = (__le64 *)range; iod->npages = 0; - } else if (psegs) { + } else if (req->nr_phys_segments) { dma_dir = rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE; - sg_init_table(iod->sg, psegs); + sg_init_table(iod->sg, req->nr_phys_segments); iod->nents = blk_rq_map_sg(req->q, req, iod->sg); if (!iod->nents) goto error_cmd; @@ -1137,21 +1194,14 @@ static void nvme_free_queue(struct nvme_queue *nvmeq) static void nvme_free_queues(struct nvme_dev *dev, int lowest) { - LLIST_HEAD(q_list); - struct nvme_queue *nvmeq, *next; - struct llist_node *entry; int i; for (i = dev->queue_count - 1; i >= lowest; i--) { struct nvme_queue *nvmeq = dev->queues[i]; - llist_add(&nvmeq->node, &q_list); dev->queue_count--; dev->queues[i] = NULL; - } - synchronize_rcu(); - entry = llist_del_all(&q_list); - llist_for_each_entry_safe(nvmeq, next, entry, node) nvme_free_queue(nvmeq); + } } /** @@ -1408,7 +1458,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev) dev->admin_tagset.queue_depth = NVME_AQ_DEPTH - 1; dev->admin_tagset.timeout = ADMIN_TIMEOUT; dev->admin_tagset.numa_node = dev_to_node(&dev->pci_dev->dev); - dev->admin_tagset.cmd_size = sizeof(struct nvme_cmd_info); + dev->admin_tagset.cmd_size = nvme_cmd_size(dev); dev->admin_tagset.driver_data = dev; if (blk_mq_alloc_tag_set(&dev->admin_tagset)) @@ -1522,7 +1572,7 @@ struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write, } err = -ENOMEM; - iod = nvme_alloc_iod(count, length, dev, GFP_KERNEL); + iod = __nvme_alloc_iod(count, length, dev, 0, GFP_KERNEL); if (!iod) goto put_pages; @@ -2148,7 +2198,7 @@ static int nvme_dev_add(struct nvme_dev *dev) dev->tagset.numa_node = dev_to_node(&dev->pci_dev->dev); dev->tagset.queue_depth = min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1; - dev->tagset.cmd_size = sizeof(struct nvme_cmd_info); + dev->tagset.cmd_size = nvme_cmd_size(dev); dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE; dev->tagset.driver_data = dev; diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c index 79aa179305b5..e22942596207 100644 --- a/drivers/block/osdblk.c +++ b/drivers/block/osdblk.c @@ -423,7 +423,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev) } /* switch queue to TCQ mode; allocate tag map */ - rc = blk_queue_init_tags(q, OSDBLK_MAX_REQ, NULL); + rc = blk_queue_init_tags(q, OSDBLK_MAX_REQ, NULL, BLK_TAG_ALLOC_FIFO); if (rc) { blk_cleanup_queue(q); put_disk(disk); diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index cdfbd21e3597..655e570b9b31 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -28,8 +28,7 @@ struct virtio_blk_vq { char name[VQ_NAME_LEN]; } ____cacheline_aligned_in_smp; -struct virtio_blk -{ +struct virtio_blk { struct virtio_device *vdev; /* The disk structure for the kernel. */ @@ -52,8 +51,7 @@ struct virtio_blk struct virtio_blk_vq *vqs; }; -struct virtblk_req -{ +struct virtblk_req { struct request *req; struct virtio_blk_outhdr out_hdr; struct virtio_scsi_inhdr in_hdr; @@ -575,6 +573,12 @@ static int virtblk_probe(struct virtio_device *vdev) u16 min_io_size; u8 physical_block_exp, alignment_offset; + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS), GFP_KERNEL); if (err < 0) diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 63fc7f06a014..2a04d341e598 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -47,6 +47,7 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> #include <xen/balloon.h> +#include <xen/grant_table.h> #include "common.h" /* @@ -100,7 +101,7 @@ module_param(log_stats, int, 0644); #define BLKBACK_INVALID_HANDLE (~0) -/* Number of free pages to remove on each call to free_xenballooned_pages */ +/* Number of free pages to remove on each call to gnttab_free_pages */ #define NUM_BATCH_FREE_PAGES 10 static inline int get_free_page(struct xen_blkif *blkif, struct page **page) @@ -111,7 +112,7 @@ static inline int get_free_page(struct xen_blkif *blkif, struct page **page) if (list_empty(&blkif->free_pages)) { BUG_ON(blkif->free_pages_num != 0); spin_unlock_irqrestore(&blkif->free_pages_lock, flags); - return alloc_xenballooned_pages(1, page, false); + return gnttab_alloc_pages(1, page); } BUG_ON(blkif->free_pages_num == 0); page[0] = list_first_entry(&blkif->free_pages, struct page, lru); @@ -151,14 +152,14 @@ static inline void shrink_free_pagepool(struct xen_blkif *blkif, int num) blkif->free_pages_num--; if (++num_pages == NUM_BATCH_FREE_PAGES) { spin_unlock_irqrestore(&blkif->free_pages_lock, flags); - free_xenballooned_pages(num_pages, page); + gnttab_free_pages(num_pages, page); spin_lock_irqsave(&blkif->free_pages_lock, flags); num_pages = 0; } } spin_unlock_irqrestore(&blkif->free_pages_lock, flags); if (num_pages != 0) - free_xenballooned_pages(num_pages, page); + gnttab_free_pages(num_pages, page); } #define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page))) @@ -262,6 +263,17 @@ static void put_persistent_gnt(struct xen_blkif *blkif, atomic_dec(&blkif->persistent_gnt_in_use); } +static void free_persistent_gnts_unmap_callback(int result, + struct gntab_unmap_queue_data *data) +{ + struct completion *c = data->data; + + /* BUG_ON used to reproduce existing behaviour, + but is this the best way to deal with this? */ + BUG_ON(result); + complete(c); +} + static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, unsigned int num) { @@ -269,8 +281,17 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; struct persistent_gnt *persistent_gnt; struct rb_node *n; - int ret = 0; int segs_to_unmap = 0; + struct gntab_unmap_queue_data unmap_data; + struct completion unmap_completion; + + init_completion(&unmap_completion); + + unmap_data.data = &unmap_completion; + unmap_data.done = &free_persistent_gnts_unmap_callback; + unmap_data.pages = pages; + unmap_data.unmap_ops = unmap; + unmap_data.kunmap_ops = NULL; foreach_grant_safe(persistent_gnt, n, root, node) { BUG_ON(persistent_gnt->handle == @@ -285,9 +306,11 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST || !rb_next(&persistent_gnt->node)) { - ret = gnttab_unmap_refs(unmap, NULL, pages, - segs_to_unmap); - BUG_ON(ret); + + unmap_data.count = segs_to_unmap; + gnttab_unmap_refs_async(&unmap_data); + wait_for_completion(&unmap_completion); + put_free_pages(blkif, pages, segs_to_unmap); segs_to_unmap = 0; } @@ -653,18 +676,14 @@ void xen_blkbk_free_caches(struct xen_blkif *blkif) shrink_free_pagepool(blkif, 0 /* All */); } -/* - * Unmap the grant references, and also remove the M2P over-rides - * used in the 'pending_req'. - */ -static void xen_blkbk_unmap(struct xen_blkif *blkif, - struct grant_page *pages[], - int num) +static unsigned int xen_blkbk_unmap_prepare( + struct xen_blkif *blkif, + struct grant_page **pages, + unsigned int num, + struct gnttab_unmap_grant_ref *unmap_ops, + struct page **unmap_pages) { - struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - struct page *unmap_pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; unsigned int i, invcount = 0; - int ret; for (i = 0; i < num; i++) { if (pages[i]->persistent_gnt != NULL) { @@ -674,21 +693,95 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif, if (pages[i]->handle == BLKBACK_INVALID_HANDLE) continue; unmap_pages[invcount] = pages[i]->page; - gnttab_set_unmap_op(&unmap[invcount], vaddr(pages[i]->page), + gnttab_set_unmap_op(&unmap_ops[invcount], vaddr(pages[i]->page), GNTMAP_host_map, pages[i]->handle); pages[i]->handle = BLKBACK_INVALID_HANDLE; - if (++invcount == BLKIF_MAX_SEGMENTS_PER_REQUEST) { - ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, - invcount); + invcount++; + } + + return invcount; +} + +static void xen_blkbk_unmap_and_respond_callback(int result, struct gntab_unmap_queue_data *data) +{ + struct pending_req* pending_req = (struct pending_req*) (data->data); + struct xen_blkif *blkif = pending_req->blkif; + + /* BUG_ON used to reproduce existing behaviour, + but is this the best way to deal with this? */ + BUG_ON(result); + + put_free_pages(blkif, data->pages, data->count); + make_response(blkif, pending_req->id, + pending_req->operation, pending_req->status); + free_req(blkif, pending_req); + /* + * Make sure the request is freed before releasing blkif, + * or there could be a race between free_req and the + * cleanup done in xen_blkif_free during shutdown. + * + * NB: The fact that we might try to wake up pending_free_wq + * before drain_complete (in case there's a drain going on) + * it's not a problem with our current implementation + * because we can assure there's no thread waiting on + * pending_free_wq if there's a drain going on, but it has + * to be taken into account if the current model is changed. + */ + if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) { + complete(&blkif->drain_complete); + } + xen_blkif_put(blkif); +} + +static void xen_blkbk_unmap_and_respond(struct pending_req *req) +{ + struct gntab_unmap_queue_data* work = &req->gnttab_unmap_data; + struct xen_blkif *blkif = req->blkif; + struct grant_page **pages = req->segments; + unsigned int invcount; + + invcount = xen_blkbk_unmap_prepare(blkif, pages, req->nr_pages, + req->unmap, req->unmap_pages); + + work->data = req; + work->done = xen_blkbk_unmap_and_respond_callback; + work->unmap_ops = req->unmap; + work->kunmap_ops = NULL; + work->pages = req->unmap_pages; + work->count = invcount; + + gnttab_unmap_refs_async(&req->gnttab_unmap_data); +} + + +/* + * Unmap the grant references. + * + * This could accumulate ops up to the batch size to reduce the number + * of hypercalls, but since this is only used in error paths there's + * no real need. + */ +static void xen_blkbk_unmap(struct xen_blkif *blkif, + struct grant_page *pages[], + int num) +{ + struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct page *unmap_pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + unsigned int invcount = 0; + int ret; + + while (num) { + unsigned int batch = min(num, BLKIF_MAX_SEGMENTS_PER_REQUEST); + + invcount = xen_blkbk_unmap_prepare(blkif, pages, batch, + unmap, unmap_pages); + if (invcount) { + ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount); BUG_ON(ret); put_free_pages(blkif, unmap_pages, invcount); - invcount = 0; } - } - if (invcount) { - ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount); - BUG_ON(ret); - put_free_pages(blkif, unmap_pages, invcount); + pages += batch; + num -= batch; } } @@ -982,32 +1075,8 @@ static void __end_block_io_op(struct pending_req *pending_req, int error) * the grant references associated with 'request' and provide * the proper response on the ring. */ - if (atomic_dec_and_test(&pending_req->pendcnt)) { - struct xen_blkif *blkif = pending_req->blkif; - - xen_blkbk_unmap(blkif, - pending_req->segments, - pending_req->nr_pages); - make_response(blkif, pending_req->id, - pending_req->operation, pending_req->status); - free_req(blkif, pending_req); - /* - * Make sure the request is freed before releasing blkif, - * or there could be a race between free_req and the - * cleanup done in xen_blkif_free during shutdown. - * - * NB: The fact that we might try to wake up pending_free_wq - * before drain_complete (in case there's a drain going on) - * it's not a problem with our current implementation - * because we can assure there's no thread waiting on - * pending_free_wq if there's a drain going on, but it has - * to be taken into account if the current model is changed. - */ - if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) { - complete(&blkif->drain_complete); - } - xen_blkif_put(blkif); - } + if (atomic_dec_and_test(&pending_req->pendcnt)) + xen_blkbk_unmap_and_respond(pending_req); } /* diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index f65b807e3236..375d28851860 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -214,6 +214,15 @@ enum blkif_protocol { BLKIF_PROTOCOL_X86_64 = 3, }; +/* + * Default protocol if the frontend doesn't specify one. + */ +#ifdef CONFIG_X86 +# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_X86_32 +#else +# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_NATIVE +#endif + struct xen_vbd { /* What the domain refers to this vbd as. */ blkif_vdev_t handle; @@ -350,6 +359,9 @@ struct pending_req { struct grant_page *indirect_pages[MAX_INDIRECT_PAGES]; struct seg_buf seg[MAX_INDIRECT_SEGMENTS]; struct bio *biolist[MAX_INDIRECT_SEGMENTS]; + struct gnttab_unmap_grant_ref unmap[MAX_INDIRECT_SEGMENTS]; + struct page *unmap_pages[MAX_INDIRECT_SEGMENTS]; + struct gntab_unmap_queue_data gnttab_unmap_data; }; diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 630a489e757d..e3afe97280b1 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -868,11 +868,11 @@ static int connect_ring(struct backend_info *be) return err; } - be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; + be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", "%63s", protocol, NULL); if (err) - strcpy(protocol, "unspecified, assuming native"); + strcpy(protocol, "unspecified, assuming default"); else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2236c6f31608..37779e4c4585 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1391,7 +1391,7 @@ static int blkfront_probe(struct xenbus_device *dev, if (major != XENVBD_MAJOR) { printk(KERN_INFO "%s: HVM does not support vbd %d as xen block device\n", - __FUNCTION__, vdevice); + __func__, vdevice); return -ENODEV; } } @@ -1511,7 +1511,7 @@ static int blkif_recover(struct blkfront_info *info) merge_bio.tail = copy[i].request->biotail; bio_list_merge(&bio_list, &merge_bio); copy[i].request->bio = NULL; - blk_put_request(copy[i].request); + blk_end_request_all(copy[i].request, 0); } kfree(copy); @@ -1534,7 +1534,7 @@ static int blkif_recover(struct blkfront_info *info) req->bio = NULL; if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) pr_alert("diskcache flush request found!\n"); - __blk_put_request(info->rq, req); + __blk_end_request_all(req, 0); } spin_unlock_irq(&info->io_lock); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index bd8bda386e02..8e233edd7a09 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -53,9 +53,9 @@ static ssize_t name##_show(struct device *d, \ } \ static DEVICE_ATTR_RO(name); -static inline int init_done(struct zram *zram) +static inline bool init_done(struct zram *zram) { - return zram->meta != NULL; + return zram->disksize; } static inline struct zram *dev_to_zram(struct device *dev) @@ -307,42 +307,67 @@ static inline int valid_io_request(struct zram *zram, return 1; } -static void zram_meta_free(struct zram_meta *meta) +static void zram_meta_free(struct zram_meta *meta, u64 disksize) { + size_t num_pages = disksize >> PAGE_SHIFT; + size_t index; + + /* Free all pages that are still in this zram device */ + for (index = 0; index < num_pages; index++) { + unsigned long handle = meta->table[index].handle; + + if (!handle) + continue; + + zs_free(meta->mem_pool, handle); + } + zs_destroy_pool(meta->mem_pool); vfree(meta->table); kfree(meta); } -static struct zram_meta *zram_meta_alloc(u64 disksize) +static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) { size_t num_pages; + char pool_name[8]; struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); + if (!meta) - goto out; + return NULL; num_pages = disksize >> PAGE_SHIFT; meta->table = vzalloc(num_pages * sizeof(*meta->table)); if (!meta->table) { pr_err("Error allocating zram address table\n"); - goto free_meta; + goto out_error; } - meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM); + snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); + meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM); if (!meta->mem_pool) { pr_err("Error creating memory pool\n"); - goto free_table; + goto out_error; } return meta; -free_table: +out_error: vfree(meta->table); -free_meta: kfree(meta); - meta = NULL; -out: - return meta; + return NULL; +} + +static inline bool zram_meta_get(struct zram *zram) +{ + if (atomic_inc_not_zero(&zram->refcount)) + return true; + return false; +} + +static inline void zram_meta_put(struct zram *zram) +{ + atomic_dec(&zram->refcount); } static void update_position(u32 *index, int *offset, struct bio_vec *bvec) @@ -704,10 +729,11 @@ static void zram_bio_discard(struct zram *zram, u32 index, } } -static void zram_reset_device(struct zram *zram, bool reset_capacity) +static void zram_reset_device(struct zram *zram) { - size_t index; struct zram_meta *meta; + struct zcomp *comp; + u64 disksize; down_write(&zram->init_lock); @@ -719,36 +745,30 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) } meta = zram->meta; - /* Free all pages that are still in this zram device */ - for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { - unsigned long handle = meta->table[index].handle; - if (!handle) - continue; - - zs_free(meta->mem_pool, handle); - } - - zcomp_destroy(zram->comp); - zram->max_comp_streams = 1; + comp = zram->comp; + disksize = zram->disksize; + /* + * Refcount will go down to 0 eventually and r/w handler + * cannot handle further I/O so it will bail out by + * check zram_meta_get. + */ + zram_meta_put(zram); + /* + * We want to free zram_meta in process context to avoid + * deadlock between reclaim path and any other locks. + */ + wait_event(zram->io_done, atomic_read(&zram->refcount) == 0); - zram_meta_free(zram->meta); - zram->meta = NULL; /* Reset stats */ memset(&zram->stats, 0, sizeof(zram->stats)); - zram->disksize = 0; - if (reset_capacity) - set_capacity(zram->disk, 0); + zram->max_comp_streams = 1; + set_capacity(zram->disk, 0); up_write(&zram->init_lock); - - /* - * Revalidate disk out of the init_lock to avoid lockdep splat. - * It's okay because disk's capacity is protected by init_lock - * so that revalidate_disk always sees up-to-date capacity. - */ - if (reset_capacity) - revalidate_disk(zram->disk); + /* I/O operation under all of CPU are done so let's free */ + zram_meta_free(meta, disksize); + zcomp_destroy(comp); } static ssize_t disksize_store(struct device *dev, @@ -765,7 +785,7 @@ static ssize_t disksize_store(struct device *dev, return -EINVAL; disksize = PAGE_ALIGN(disksize); - meta = zram_meta_alloc(disksize); + meta = zram_meta_alloc(zram->disk->first_minor, disksize); if (!meta) return -ENOMEM; @@ -784,6 +804,8 @@ static ssize_t disksize_store(struct device *dev, goto out_destroy_comp; } + init_waitqueue_head(&zram->io_done); + atomic_set(&zram->refcount, 1); zram->meta = meta; zram->comp = comp; zram->disksize = disksize; @@ -803,7 +825,7 @@ out_destroy_comp: up_write(&zram->init_lock); zcomp_destroy(comp); out_free_meta: - zram_meta_free(meta); + zram_meta_free(meta, disksize); return err; } @@ -821,8 +843,9 @@ static ssize_t reset_store(struct device *dev, if (!bdev) return -ENOMEM; + mutex_lock(&bdev->bd_mutex); /* Do not reset an active device! */ - if (bdev->bd_holders) { + if (bdev->bd_openers) { ret = -EBUSY; goto out; } @@ -838,12 +861,16 @@ static ssize_t reset_store(struct device *dev, /* Make sure all pending I/O is finished */ fsync_bdev(bdev); + zram_reset_device(zram); + + mutex_unlock(&bdev->bd_mutex); + revalidate_disk(zram->disk); bdput(bdev); - zram_reset_device(zram, true); return len; out: + mutex_unlock(&bdev->bd_mutex); bdput(bdev); return ret; } @@ -909,23 +936,21 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio) { struct zram *zram = queue->queuedata; - down_read(&zram->init_lock); - if (unlikely(!init_done(zram))) + if (unlikely(!zram_meta_get(zram))) goto error; if (!valid_io_request(zram, bio->bi_iter.bi_sector, bio->bi_iter.bi_size)) { atomic64_inc(&zram->stats.invalid_io); - goto error; + goto put_zram; } __zram_make_request(zram, bio); - up_read(&zram->init_lock); - + zram_meta_put(zram); return; - +put_zram: + zram_meta_put(zram); error: - up_read(&zram->init_lock); bio_io_error(bio); } @@ -947,21 +972,19 @@ static void zram_slot_free_notify(struct block_device *bdev, static int zram_rw_page(struct block_device *bdev, sector_t sector, struct page *page, int rw) { - int offset, err; + int offset, err = -EIO; u32 index; struct zram *zram; struct bio_vec bv; zram = bdev->bd_disk->private_data; + if (unlikely(!zram_meta_get(zram))) + goto out; + if (!valid_io_request(zram, sector, PAGE_SIZE)) { atomic64_inc(&zram->stats.invalid_io); - return -EINVAL; - } - - down_read(&zram->init_lock); - if (unlikely(!init_done(zram))) { - err = -EIO; - goto out_unlock; + err = -EINVAL; + goto put_zram; } index = sector >> SECTORS_PER_PAGE_SHIFT; @@ -972,8 +995,9 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector, bv.bv_offset = 0; err = zram_bvec_rw(zram, &bv, index, offset, rw); -out_unlock: - up_read(&zram->init_lock); +put_zram: + zram_meta_put(zram); +out: /* * If I/O fails, just return error(ie, non-zero) without * calling page_endio. @@ -1039,19 +1063,19 @@ static struct attribute_group zram_disk_attr_group = { static int create_device(struct zram *zram, int device_id) { + struct request_queue *queue; int ret = -ENOMEM; init_rwsem(&zram->init_lock); - zram->queue = blk_alloc_queue(GFP_KERNEL); - if (!zram->queue) { + queue = blk_alloc_queue(GFP_KERNEL); + if (!queue) { pr_err("Error allocating disk queue for device %d\n", device_id); goto out; } - blk_queue_make_request(zram->queue, zram_make_request); - zram->queue->queuedata = zram; + blk_queue_make_request(queue, zram_make_request); /* gendisk structure */ zram->disk = alloc_disk(1); @@ -1064,7 +1088,8 @@ static int create_device(struct zram *zram, int device_id) zram->disk->major = zram_major; zram->disk->first_minor = device_id; zram->disk->fops = &zram_devops; - zram->disk->queue = zram->queue; + zram->disk->queue = queue; + zram->disk->queue->queuedata = zram; zram->disk->private_data = zram; snprintf(zram->disk->disk_name, 16, "zram%d", device_id); @@ -1115,20 +1140,35 @@ out_free_disk: del_gendisk(zram->disk); put_disk(zram->disk); out_free_queue: - blk_cleanup_queue(zram->queue); + blk_cleanup_queue(queue); out: return ret; } -static void destroy_device(struct zram *zram) +static void destroy_devices(unsigned int nr) { - sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, - &zram_disk_attr_group); + struct zram *zram; + unsigned int i; - del_gendisk(zram->disk); - put_disk(zram->disk); + for (i = 0; i < nr; i++) { + zram = &zram_devices[i]; + /* + * Remove sysfs first, so no one will perform a disksize + * store while we destroy the devices + */ + sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, + &zram_disk_attr_group); + + zram_reset_device(zram); - blk_cleanup_queue(zram->queue); + blk_cleanup_queue(zram->disk->queue); + del_gendisk(zram->disk); + put_disk(zram->disk); + } + + kfree(zram_devices); + unregister_blkdev(zram_major, "zram"); + pr_info("Destroyed %u device(s)\n", nr); } static int __init zram_init(void) @@ -1138,64 +1178,39 @@ static int __init zram_init(void) if (num_devices > max_num_devices) { pr_warn("Invalid value for num_devices: %u\n", num_devices); - ret = -EINVAL; - goto out; + return -EINVAL; } zram_major = register_blkdev(0, "zram"); if (zram_major <= 0) { pr_warn("Unable to get major number\n"); - ret = -EBUSY; - goto out; + return -EBUSY; } /* Allocate the device array and initialize each one */ zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); if (!zram_devices) { - ret = -ENOMEM; - goto unregister; + unregister_blkdev(zram_major, "zram"); + return -ENOMEM; } for (dev_id = 0; dev_id < num_devices; dev_id++) { ret = create_device(&zram_devices[dev_id], dev_id); if (ret) - goto free_devices; + goto out_error; } - pr_info("Created %u device(s) ...\n", num_devices); - + pr_info("Created %u device(s)\n", num_devices); return 0; -free_devices: - while (dev_id) - destroy_device(&zram_devices[--dev_id]); - kfree(zram_devices); -unregister: - unregister_blkdev(zram_major, "zram"); -out: +out_error: + destroy_devices(dev_id); return ret; } static void __exit zram_exit(void) { - int i; - struct zram *zram; - - for (i = 0; i < num_devices; i++) { - zram = &zram_devices[i]; - - destroy_device(zram); - /* - * Shouldn't access zram->disk after destroy_device - * because destroy_device already released zram->disk. - */ - zram_reset_device(zram, false); - } - - unregister_blkdev(zram_major, "zram"); - - kfree(zram_devices); - pr_debug("Cleanup done!\n"); + destroy_devices(num_devices); } module_init(zram_init); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index b05a816b09ac..17056e589146 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -100,24 +100,25 @@ struct zram_meta { struct zram { struct zram_meta *meta; - struct request_queue *queue; - struct gendisk *disk; struct zcomp *comp; - - /* Prevent concurrent execution of device init, reset and R/W request */ + struct gendisk *disk; + /* Prevent concurrent execution of device init */ struct rw_semaphore init_lock; /* - * This is the limit on amount of *uncompressed* worth of data - * we can store in a disk. + * the number of pages zram can consume for storing compressed data */ - u64 disksize; /* bytes */ + unsigned long limit_pages; int max_comp_streams; + struct zram_stats stats; + atomic_t refcount; /* refcount for zram_meta */ + /* wait all IO under all of cpu are done */ + wait_queue_head_t io_done; /* - * the number of pages zram can consume for storing compressed data + * This is the limit on amount of *uncompressed* worth of data + * we can store in a disk. */ - unsigned long limit_pages; - + u64 disksize; /* bytes */ char compressor[10]; }; #endif |