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261 lines
6.4 KiB
261 lines
6.4 KiB
/* |
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* Copyright (C) 2001-2003 Sistina Software (UK) Limited. |
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* |
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* This file is released under the GPL. |
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*/ |
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#include "dm.h" |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/blkdev.h> |
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#include <linux/bio.h> |
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#include <linux/dax.h> |
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#include <linux/slab.h> |
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#include <linux/device-mapper.h> |
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#define DM_MSG_PREFIX "linear" |
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/* |
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* Linear: maps a linear range of a device. |
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*/ |
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struct linear_c { |
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struct dm_dev *dev; |
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sector_t start; |
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}; |
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/* |
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* Construct a linear mapping: <dev_path> <offset> |
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*/ |
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static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
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{ |
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struct linear_c *lc; |
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unsigned long long tmp; |
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char dummy; |
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int ret; |
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if (argc != 2) { |
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ti->error = "Invalid argument count"; |
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return -EINVAL; |
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} |
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lc = kmalloc(sizeof(*lc), GFP_KERNEL); |
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if (lc == NULL) { |
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ti->error = "Cannot allocate linear context"; |
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return -ENOMEM; |
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} |
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ret = -EINVAL; |
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if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) { |
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ti->error = "Invalid device sector"; |
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goto bad; |
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} |
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lc->start = tmp; |
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ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev); |
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if (ret) { |
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ti->error = "Device lookup failed"; |
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goto bad; |
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} |
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ti->num_flush_bios = 1; |
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ti->num_discard_bios = 1; |
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ti->num_secure_erase_bios = 1; |
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ti->num_write_same_bios = 1; |
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ti->num_write_zeroes_bios = 1; |
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ti->private = lc; |
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return 0; |
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bad: |
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kfree(lc); |
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return ret; |
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} |
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static void linear_dtr(struct dm_target *ti) |
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{ |
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struct linear_c *lc = (struct linear_c *) ti->private; |
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dm_put_device(ti, lc->dev); |
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kfree(lc); |
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} |
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static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector) |
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{ |
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struct linear_c *lc = ti->private; |
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return lc->start + dm_target_offset(ti, bi_sector); |
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} |
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static void linear_map_bio(struct dm_target *ti, struct bio *bio) |
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{ |
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struct linear_c *lc = ti->private; |
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bio_set_dev(bio, lc->dev->bdev); |
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if (bio_sectors(bio) || op_is_zone_mgmt(bio_op(bio))) |
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bio->bi_iter.bi_sector = |
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linear_map_sector(ti, bio->bi_iter.bi_sector); |
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} |
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static int linear_map(struct dm_target *ti, struct bio *bio) |
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{ |
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linear_map_bio(ti, bio); |
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return DM_MAPIO_REMAPPED; |
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} |
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static void linear_status(struct dm_target *ti, status_type_t type, |
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unsigned status_flags, char *result, unsigned maxlen) |
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{ |
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struct linear_c *lc = (struct linear_c *) ti->private; |
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switch (type) { |
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case STATUSTYPE_INFO: |
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result[0] = '\0'; |
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break; |
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case STATUSTYPE_TABLE: |
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snprintf(result, maxlen, "%s %llu", lc->dev->name, |
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(unsigned long long)lc->start); |
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break; |
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} |
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} |
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static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev) |
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{ |
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struct linear_c *lc = (struct linear_c *) ti->private; |
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struct dm_dev *dev = lc->dev; |
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*bdev = dev->bdev; |
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/* |
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* Only pass ioctls through if the device sizes match exactly. |
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*/ |
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if (lc->start || |
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ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT) |
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return 1; |
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return 0; |
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} |
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#ifdef CONFIG_BLK_DEV_ZONED |
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static int linear_report_zones(struct dm_target *ti, |
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struct dm_report_zones_args *args, unsigned int nr_zones) |
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{ |
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struct linear_c *lc = ti->private; |
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sector_t sector = linear_map_sector(ti, args->next_sector); |
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args->start = lc->start; |
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return blkdev_report_zones(lc->dev->bdev, sector, nr_zones, |
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dm_report_zones_cb, args); |
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} |
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#else |
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#define linear_report_zones NULL |
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#endif |
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static int linear_iterate_devices(struct dm_target *ti, |
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iterate_devices_callout_fn fn, void *data) |
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{ |
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struct linear_c *lc = ti->private; |
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return fn(ti, lc->dev, lc->start, ti->len, data); |
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} |
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#if IS_ENABLED(CONFIG_DAX_DRIVER) |
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static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, |
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long nr_pages, void **kaddr, pfn_t *pfn) |
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{ |
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long ret; |
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struct linear_c *lc = ti->private; |
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struct block_device *bdev = lc->dev->bdev; |
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struct dax_device *dax_dev = lc->dev->dax_dev; |
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sector_t dev_sector, sector = pgoff * PAGE_SECTORS; |
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dev_sector = linear_map_sector(ti, sector); |
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ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff); |
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if (ret) |
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return ret; |
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return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn); |
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} |
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static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, |
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void *addr, size_t bytes, struct iov_iter *i) |
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{ |
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struct linear_c *lc = ti->private; |
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struct block_device *bdev = lc->dev->bdev; |
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struct dax_device *dax_dev = lc->dev->dax_dev; |
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sector_t dev_sector, sector = pgoff * PAGE_SECTORS; |
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dev_sector = linear_map_sector(ti, sector); |
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if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) |
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return 0; |
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return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i); |
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} |
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static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff, |
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void *addr, size_t bytes, struct iov_iter *i) |
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{ |
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struct linear_c *lc = ti->private; |
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struct block_device *bdev = lc->dev->bdev; |
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struct dax_device *dax_dev = lc->dev->dax_dev; |
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sector_t dev_sector, sector = pgoff * PAGE_SECTORS; |
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dev_sector = linear_map_sector(ti, sector); |
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if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) |
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return 0; |
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return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i); |
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} |
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static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff, |
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size_t nr_pages) |
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{ |
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int ret; |
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struct linear_c *lc = ti->private; |
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struct block_device *bdev = lc->dev->bdev; |
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struct dax_device *dax_dev = lc->dev->dax_dev; |
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sector_t dev_sector, sector = pgoff * PAGE_SECTORS; |
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dev_sector = linear_map_sector(ti, sector); |
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ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff); |
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if (ret) |
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return ret; |
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return dax_zero_page_range(dax_dev, pgoff, nr_pages); |
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} |
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#else |
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#define linear_dax_direct_access NULL |
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#define linear_dax_copy_from_iter NULL |
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#define linear_dax_copy_to_iter NULL |
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#define linear_dax_zero_page_range NULL |
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#endif |
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static struct target_type linear_target = { |
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.name = "linear", |
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.version = {1, 4, 0}, |
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.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT | |
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DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO, |
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.report_zones = linear_report_zones, |
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.module = THIS_MODULE, |
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.ctr = linear_ctr, |
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.dtr = linear_dtr, |
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.map = linear_map, |
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.status = linear_status, |
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.prepare_ioctl = linear_prepare_ioctl, |
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.iterate_devices = linear_iterate_devices, |
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.direct_access = linear_dax_direct_access, |
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.dax_copy_from_iter = linear_dax_copy_from_iter, |
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.dax_copy_to_iter = linear_dax_copy_to_iter, |
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.dax_zero_page_range = linear_dax_zero_page_range, |
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}; |
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int __init dm_linear_init(void) |
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{ |
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int r = dm_register_target(&linear_target); |
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if (r < 0) |
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DMERR("register failed %d", r); |
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return r; |
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} |
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void dm_linear_exit(void) |
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{ |
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dm_unregister_target(&linear_target); |
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}
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