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![Kent Overstreet](/assets/img/avatar_default.png)
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
182 lines
3.8 KiB
C
182 lines
3.8 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/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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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 = "dm-linear: Cannot allocate linear context";
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return -ENOMEM;
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}
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if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
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ti->error = "dm-linear: Invalid device sector";
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goto bad;
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}
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lc->start = tmp;
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if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
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ti->error = "dm-linear: 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_write_same_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 -EINVAL;
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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->bi_bdev = lc->dev->bdev;
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if (bio_sectors(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_ioctl(struct dm_target *ti, unsigned int cmd,
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unsigned long arg)
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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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int r = 0;
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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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r = scsi_verify_blk_ioctl(NULL, cmd);
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return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
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}
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static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
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struct bio_vec *biovec, int max_size)
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{
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struct linear_c *lc = ti->private;
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struct request_queue *q = bdev_get_queue(lc->dev->bdev);
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if (!q->merge_bvec_fn)
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return max_size;
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bvm->bi_bdev = lc->dev->bdev;
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bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector);
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return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
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}
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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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static struct target_type linear_target = {
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.name = "linear",
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.version = {1, 2, 1},
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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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.ioctl = linear_ioctl,
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.merge = linear_merge,
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.iterate_devices = linear_iterate_devices,
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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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