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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/md/dm-linear.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/md/dm-linear.c')
-rw-r--r-- | drivers/md/dm-linear.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c new file mode 100644 index 0000000..6a2cd5d --- /dev/null +++ b/drivers/md/dm-linear.c @@ -0,0 +1,123 @@ +/* + * Copyright (C) 2001-2003 Sistina Software (UK) Limited. + * + * This file is released under the GPL. + */ + +#include "dm.h" + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/blkdev.h> +#include <linux/bio.h> +#include <linux/slab.h> + +/* + * Linear: maps a linear range of a device. + */ +struct linear_c { + struct dm_dev *dev; + sector_t start; +}; + +/* + * Construct a linear mapping: <dev_path> <offset> + */ +static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct linear_c *lc; + + if (argc != 2) { + ti->error = "dm-linear: Invalid argument count"; + return -EINVAL; + } + + lc = kmalloc(sizeof(*lc), GFP_KERNEL); + if (lc == NULL) { + ti->error = "dm-linear: Cannot allocate linear context"; + return -ENOMEM; + } + + if (sscanf(argv[1], SECTOR_FORMAT, &lc->start) != 1) { + ti->error = "dm-linear: Invalid device sector"; + goto bad; + } + + if (dm_get_device(ti, argv[0], lc->start, ti->len, + dm_table_get_mode(ti->table), &lc->dev)) { + ti->error = "dm-linear: Device lookup failed"; + goto bad; + } + + ti->private = lc; + return 0; + + bad: + kfree(lc); + return -EINVAL; +} + +static void linear_dtr(struct dm_target *ti) +{ + struct linear_c *lc = (struct linear_c *) ti->private; + + dm_put_device(ti, lc->dev); + kfree(lc); +} + +static int linear_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + struct linear_c *lc = (struct linear_c *) ti->private; + + bio->bi_bdev = lc->dev->bdev; + bio->bi_sector = lc->start + (bio->bi_sector - ti->begin); + + return 1; +} + +static int linear_status(struct dm_target *ti, status_type_t type, + char *result, unsigned int maxlen) +{ + struct linear_c *lc = (struct linear_c *) ti->private; + + switch (type) { + case STATUSTYPE_INFO: + result[0] = '\0'; + break; + + case STATUSTYPE_TABLE: + snprintf(result, maxlen, "%s " SECTOR_FORMAT, lc->dev->name, + lc->start); + break; + } + return 0; +} + +static struct target_type linear_target = { + .name = "linear", + .version= {1, 0, 1}, + .module = THIS_MODULE, + .ctr = linear_ctr, + .dtr = linear_dtr, + .map = linear_map, + .status = linear_status, +}; + +int __init dm_linear_init(void) +{ + int r = dm_register_target(&linear_target); + + if (r < 0) + DMERR("linear: register failed %d", r); + + return r; +} + +void dm_linear_exit(void) +{ + int r = dm_unregister_target(&linear_target); + + if (r < 0) + DMERR("linear: unregister failed %d", r); +} |