267 lines
6.5 KiB
C
267 lines
6.5 KiB
C
/*
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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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size_t sz = 0;
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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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DMEMIT("%s %llu", lc->dev->name, (unsigned long long)lc->start);
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break;
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case STATUSTYPE_IMA:
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DMEMIT_TARGET_NAME_VERSION(ti->type);
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DMEMIT(",device_name=%s,start=%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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return dm_report_zones(lc->dev->bdev, lc->start,
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linear_map_sector(ti, args->next_sector),
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args, nr_zones);
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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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