From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 09/13] bdi: remove BDI_CAP_SYNCHRONOUS_IO Date: Thu, 24 Sep 2020 08:51:36 +0200 Message-ID: <20200924065140.726436-10-hch@lst.de> References: <20200924065140.726436-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200924065140.726436-1-hch@lst.de> To: Jens Axboe Cc: Song Liu , Hans de Goede , Coly Li , Richard Weinberger , Minchan Kim , Johannes Thumshirn , Justin Sanders , linux-mtd@lists.infradead.org, dm-devel@redhat.com, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, Jan Kara , Johannes Thumshirn List-Id: dm-devel.ids BDI_CAP_SYNCHRONOUS_IO is only checked in the swap code, and used to decided if ->rw_page can be used on a block device. Just check up for the method instead. The only complication is that zram needs a second set of block_device_operations as it can switch between modes that actually support ->rw_page and those who don't. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn --- drivers/block/brd.c | 1 - drivers/block/zram/zram_drv.c | 19 +++++++++++++------ drivers/nvdimm/btt.c | 2 -- drivers/nvdimm/pmem.c | 1 - include/linux/backing-dev.h | 9 --------- mm/swapfile.c | 2 +- 6 files changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 2723a70eb85593..cc49a921339f77 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -403,7 +403,6 @@ static struct brd_device *brd_alloc(int i) disk->flags = GENHD_FL_EXT_DEVT; sprintf(disk->disk_name, "ram%d", i); set_capacity(disk, rd_size * 2); - brd->brd_queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; /* Tell the block layer that this is not a rotational device */ blk_queue_flag_set(QUEUE_FLAG_NONROT, brd->brd_queue); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 91ccfe444525b4..e21ca844d7c291 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -52,6 +52,9 @@ static unsigned int num_devices = 1; */ static size_t huge_class_size; +static const struct block_device_operations zram_devops; +static const struct block_device_operations zram_wb_devops; + static void zram_free_page(struct zram *zram, size_t index); static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio); @@ -408,8 +411,7 @@ static void reset_bdev(struct zram *zram) zram->backing_dev = NULL; zram->old_block_size = 0; zram->bdev = NULL; - zram->disk->queue->backing_dev_info->capabilities |= - BDI_CAP_SYNCHRONOUS_IO; + zram->disk->fops = &zram_devops; kvfree(zram->bitmap); zram->bitmap = NULL; } @@ -529,8 +531,7 @@ static ssize_t backing_dev_store(struct device *dev, * freely but in fact, IO is going on so finally could cause * use-after-free when the IO is really done. */ - zram->disk->queue->backing_dev_info->capabilities &= - ~BDI_CAP_SYNCHRONOUS_IO; + zram->disk->fops = &zram_wb_devops; up_write(&zram->init_lock); pr_info("setup backing device %s\n", file_name); @@ -1820,6 +1821,13 @@ static const struct block_device_operations zram_devops = { .owner = THIS_MODULE }; +static const struct block_device_operations zram_wb_devops = { + .open = zram_open, + .submit_bio = zram_submit_bio, + .swap_slot_free_notify = zram_slot_free_notify, + .owner = THIS_MODULE +}; + static DEVICE_ATTR_WO(compact); static DEVICE_ATTR_RW(disksize); static DEVICE_ATTR_RO(initstate); @@ -1947,8 +1955,7 @@ static int zram_add(void) if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) blk_queue_max_write_zeroes_sectors(zram->disk->queue, UINT_MAX); - zram->disk->queue->backing_dev_info->capabilities |= - (BDI_CAP_STABLE_WRITES | BDI_CAP_SYNCHRONOUS_IO); + zram->disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; device_add_disk(NULL, zram->disk, zram_disk_attr_groups); strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 0d710140bf93be..12ff6f8784ac11 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1537,8 +1537,6 @@ static int btt_blk_init(struct btt *btt) btt->btt_disk->private_data = btt; btt->btt_disk->queue = btt->btt_queue; btt->btt_disk->flags = GENHD_FL_EXT_DEVT; - btt->btt_disk->queue->backing_dev_info->capabilities |= - BDI_CAP_SYNCHRONOUS_IO; blk_queue_logical_block_size(btt->btt_queue, btt->sector_size); blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 140cf3b9000c60..1711fdfd8d2816 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -475,7 +475,6 @@ static int pmem_attach_disk(struct device *dev, disk->queue = q; disk->flags = GENHD_FL_EXT_DEVT; disk->private_data = pmem; - disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; nvdimm_namespace_disk_name(ndns, disk->disk_name); set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) / 512); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 52583b6f2ea05d..860ea33571bce5 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -122,9 +122,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * BDI_CAP_NO_WRITEBACK: Don't write pages back * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. - * - * BDI_CAP_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be - * inefficient. */ #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 @@ -132,7 +129,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_STABLE_WRITES 0x00000008 #define BDI_CAP_STRICTLIMIT 0x00000010 #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 -#define BDI_CAP_SYNCHRONOUS_IO 0x00000040 #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) @@ -174,11 +170,6 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi) -{ - return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO; -} - static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) { return bdi->capabilities & BDI_CAP_STABLE_WRITES; diff --git a/mm/swapfile.c b/mm/swapfile.c index b90f8692074397..96a7c47dd533e4 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3240,7 +3240,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) p->flags |= SWP_STABLE_WRITES; - if (bdi_cap_synchronous_io(inode_to_bdi(inode))) + if (p->bdev && p->bdev->bd_disk->fops->rw_page) p->flags |= SWP_SYNCHRONOUS_IO; if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { -- 2.28.0