13bd94003SHeinz Mauelshagen // SPDX-License-Identifier: GPL-2.0-only
24db6bfe0SAlasdair G Kergon /*
34db6bfe0SAlasdair G Kergon * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
44db6bfe0SAlasdair G Kergon * Copyright (C) 2006-2008 Red Hat GmbH
54db6bfe0SAlasdair G Kergon *
64db6bfe0SAlasdair G Kergon * This file is released under the GPL.
74db6bfe0SAlasdair G Kergon */
84db6bfe0SAlasdair G Kergon
94db6bfe0SAlasdair G Kergon #include "dm-exception-store.h"
104db6bfe0SAlasdair G Kergon
114db6bfe0SAlasdair G Kergon #include <linux/mm.h>
124db6bfe0SAlasdair G Kergon #include <linux/pagemap.h>
134db6bfe0SAlasdair G Kergon #include <linux/vmalloc.h>
14daaa5f7cSPaul Gortmaker #include <linux/export.h>
154db6bfe0SAlasdair G Kergon #include <linux/slab.h>
164db6bfe0SAlasdair G Kergon #include <linux/dm-io.h>
174db6bfe0SAlasdair G Kergon
184db6bfe0SAlasdair G Kergon #define DM_MSG_PREFIX "transient snapshot"
194db6bfe0SAlasdair G Kergon
20a4a82ce3SHeinz Mauelshagen /*
21a4a82ce3SHeinz Mauelshagen *---------------------------------------------------------------
224db6bfe0SAlasdair G Kergon * Implementation of the store for non-persistent snapshots.
23a4a82ce3SHeinz Mauelshagen *---------------------------------------------------------------
24a4a82ce3SHeinz Mauelshagen */
254db6bfe0SAlasdair G Kergon struct transient_c {
264db6bfe0SAlasdair G Kergon sector_t next_free;
274db6bfe0SAlasdair G Kergon };
284db6bfe0SAlasdair G Kergon
transient_dtr(struct dm_exception_store * store)29493df71cSJonathan Brassow static void transient_dtr(struct dm_exception_store *store)
304db6bfe0SAlasdair G Kergon {
314db6bfe0SAlasdair G Kergon kfree(store->context);
324db6bfe0SAlasdair G Kergon }
334db6bfe0SAlasdair G Kergon
transient_read_metadata(struct dm_exception_store * store,int (* callback)(void * callback_context,chunk_t old,chunk_t new),void * callback_context)34a159c1acSJonathan Brassow static int transient_read_metadata(struct dm_exception_store *store,
35a159c1acSJonathan Brassow int (*callback)(void *callback_context,
36a159c1acSJonathan Brassow chunk_t old, chunk_t new),
37a159c1acSJonathan Brassow void *callback_context)
384db6bfe0SAlasdair G Kergon {
394db6bfe0SAlasdair G Kergon return 0;
404db6bfe0SAlasdair G Kergon }
414db6bfe0SAlasdair G Kergon
transient_prepare_exception(struct dm_exception_store * store,struct dm_exception * e)42a159c1acSJonathan Brassow static int transient_prepare_exception(struct dm_exception_store *store,
431d4989c8SJon Brassow struct dm_exception *e)
444db6bfe0SAlasdair G Kergon {
45b2a11465SJonathan Brassow struct transient_c *tc = store->context;
46fc56f6fbSMike Snitzer sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
474db6bfe0SAlasdair G Kergon
48d0216849SJonathan Brassow if (size < (tc->next_free + store->chunk_size))
494db6bfe0SAlasdair G Kergon return -1;
504db6bfe0SAlasdair G Kergon
5171fab00aSJonathan Brassow e->new_chunk = sector_to_chunk(store, tc->next_free);
52d0216849SJonathan Brassow tc->next_free += store->chunk_size;
534db6bfe0SAlasdair G Kergon
544db6bfe0SAlasdair G Kergon return 0;
554db6bfe0SAlasdair G Kergon }
564db6bfe0SAlasdair G Kergon
transient_commit_exception(struct dm_exception_store * store,struct dm_exception * e,int valid,void (* callback)(void *,int success),void * callback_context)57a159c1acSJonathan Brassow static void transient_commit_exception(struct dm_exception_store *store,
58385277bfSMikulas Patocka struct dm_exception *e, int valid,
594db6bfe0SAlasdair G Kergon void (*callback)(void *, int success),
604db6bfe0SAlasdair G Kergon void *callback_context)
614db6bfe0SAlasdair G Kergon {
624db6bfe0SAlasdair G Kergon /* Just succeed */
63385277bfSMikulas Patocka callback(callback_context, valid);
644db6bfe0SAlasdair G Kergon }
654db6bfe0SAlasdair G Kergon
transient_usage(struct dm_exception_store * store,sector_t * total_sectors,sector_t * sectors_allocated,sector_t * metadata_sectors)66985903bbSMike Snitzer static void transient_usage(struct dm_exception_store *store,
67985903bbSMike Snitzer sector_t *total_sectors,
68985903bbSMike Snitzer sector_t *sectors_allocated,
69985903bbSMike Snitzer sector_t *metadata_sectors)
704db6bfe0SAlasdair G Kergon {
71985903bbSMike Snitzer *sectors_allocated = ((struct transient_c *) store->context)->next_free;
72fc56f6fbSMike Snitzer *total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
73985903bbSMike Snitzer *metadata_sectors = 0;
744db6bfe0SAlasdair G Kergon }
754db6bfe0SAlasdair G Kergon
transient_ctr(struct dm_exception_store * store,char * options)76b0d3cc01SMike Snitzer static int transient_ctr(struct dm_exception_store *store, char *options)
774db6bfe0SAlasdair G Kergon {
784db6bfe0SAlasdair G Kergon struct transient_c *tc;
794db6bfe0SAlasdair G Kergon
804db6bfe0SAlasdair G Kergon tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
814db6bfe0SAlasdair G Kergon if (!tc)
824db6bfe0SAlasdair G Kergon return -ENOMEM;
834db6bfe0SAlasdair G Kergon
844db6bfe0SAlasdair G Kergon tc->next_free = 0;
854db6bfe0SAlasdair G Kergon store->context = tc;
864db6bfe0SAlasdair G Kergon
874db6bfe0SAlasdair G Kergon return 0;
884db6bfe0SAlasdair G Kergon }
894db6bfe0SAlasdair G Kergon
transient_status(struct dm_exception_store * store,status_type_t status,char * result,unsigned int maxlen)9086a3238cSHeinz Mauelshagen static unsigned int transient_status(struct dm_exception_store *store,
91493df71cSJonathan Brassow status_type_t status, char *result,
9286a3238cSHeinz Mauelshagen unsigned int maxlen)
93493df71cSJonathan Brassow {
9486a3238cSHeinz Mauelshagen unsigned int sz = 0;
951e302a92SJonathan Brassow
961e302a92SJonathan Brassow switch (status) {
971e302a92SJonathan Brassow case STATUSTYPE_INFO:
981e302a92SJonathan Brassow break;
991e302a92SJonathan Brassow case STATUSTYPE_TABLE:
100fc56f6fbSMike Snitzer DMEMIT(" N %llu", (unsigned long long)store->chunk_size);
1018ec45662STushar Sugandhi break;
1028ec45662STushar Sugandhi case STATUSTYPE_IMA:
1038ec45662STushar Sugandhi *result = '\0';
1048ec45662STushar Sugandhi break;
1051e302a92SJonathan Brassow }
106493df71cSJonathan Brassow
107493df71cSJonathan Brassow return sz;
108493df71cSJonathan Brassow }
109493df71cSJonathan Brassow
110493df71cSJonathan Brassow static struct dm_exception_store_type _transient_type = {
111493df71cSJonathan Brassow .name = "transient",
112493df71cSJonathan Brassow .module = THIS_MODULE,
113493df71cSJonathan Brassow .ctr = transient_ctr,
114493df71cSJonathan Brassow .dtr = transient_dtr,
115493df71cSJonathan Brassow .read_metadata = transient_read_metadata,
116493df71cSJonathan Brassow .prepare_exception = transient_prepare_exception,
117493df71cSJonathan Brassow .commit_exception = transient_commit_exception,
118985903bbSMike Snitzer .usage = transient_usage,
119493df71cSJonathan Brassow .status = transient_status,
120493df71cSJonathan Brassow };
121493df71cSJonathan Brassow
122493df71cSJonathan Brassow static struct dm_exception_store_type _transient_compat_type = {
123493df71cSJonathan Brassow .name = "N",
124493df71cSJonathan Brassow .module = THIS_MODULE,
125493df71cSJonathan Brassow .ctr = transient_ctr,
126493df71cSJonathan Brassow .dtr = transient_dtr,
127493df71cSJonathan Brassow .read_metadata = transient_read_metadata,
128493df71cSJonathan Brassow .prepare_exception = transient_prepare_exception,
129493df71cSJonathan Brassow .commit_exception = transient_commit_exception,
130985903bbSMike Snitzer .usage = transient_usage,
131493df71cSJonathan Brassow .status = transient_status,
132493df71cSJonathan Brassow };
133493df71cSJonathan Brassow
dm_transient_snapshot_init(void)1344db6bfe0SAlasdair G Kergon int dm_transient_snapshot_init(void)
1354db6bfe0SAlasdair G Kergon {
136493df71cSJonathan Brassow int r;
137493df71cSJonathan Brassow
138493df71cSJonathan Brassow r = dm_exception_store_type_register(&_transient_type);
139493df71cSJonathan Brassow if (r) {
140493df71cSJonathan Brassow DMWARN("Unable to register transient exception store type");
141493df71cSJonathan Brassow return r;
142493df71cSJonathan Brassow }
143493df71cSJonathan Brassow
144493df71cSJonathan Brassow r = dm_exception_store_type_register(&_transient_compat_type);
145493df71cSJonathan Brassow if (r) {
146*2e84fecfSHeinz Mauelshagen DMWARN("Unable to register old-style transient exception store type");
147493df71cSJonathan Brassow dm_exception_store_type_unregister(&_transient_type);
148493df71cSJonathan Brassow return r;
149493df71cSJonathan Brassow }
150493df71cSJonathan Brassow
151493df71cSJonathan Brassow return r;
1524db6bfe0SAlasdair G Kergon }
1534db6bfe0SAlasdair G Kergon
dm_transient_snapshot_exit(void)1544db6bfe0SAlasdair G Kergon void dm_transient_snapshot_exit(void)
1554db6bfe0SAlasdair G Kergon {
156493df71cSJonathan Brassow dm_exception_store_type_unregister(&_transient_type);
157493df71cSJonathan Brassow dm_exception_store_type_unregister(&_transient_compat_type);
1584db6bfe0SAlasdair G Kergon }
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