summaryrefslogtreecommitdiff
path: root/drivers/md/dm-cache-target.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2025-04-02 21:27:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-04-02 21:27:59 -0700
commit5014bebee0cffda14fafae5a2534d08120b7b9e8 (patch)
treecdeb23d10c019240dd207d86ed0b9a3024972838 /drivers/md/dm-cache-target.c
parent447d2d272e4e0c7cd9dfc6aeeadad9d70b3fb1ef (diff)
parent9c565428788fb9b49066f94ab7b10efc686a0a4c (diff)
Merge tag 'for-6.15/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mikulas Patocka: - dm-crypt: switch to using the crc32 library - dm-verity, dm-integrity, dm-crypt: documentation improvement - dm-vdo fixes - dm-stripe: enable inline crypto passthrough - dm-integrity: set ti->error on memory allocation failure - dm-bufio: remove unused return value - dm-verity: do forward error correction on metadata I/O errors - dm: fix unconditional IO throttle caused by REQ_PREFLUSH - dm cache: prevent BUG_ON by blocking retries on failed device resumes - dm cache: support shrinking the origin device - dm: restrict dm device size to 2^63-512 bytes - dm-delay: support zoned devices - dm-verity: support block number limits for different ioprio classes - dm-integrity: fix non-constant-time tag verification (security bug) - dm-verity, dm-ebs: fix prefetch-vs-suspend race * tag 'for-6.15/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (27 commits) dm-ebs: fix prefetch-vs-suspend race dm-verity: fix prefetch-vs-suspend race dm-integrity: fix non-constant-time tag verification dm-verity: support block number limits for different ioprio classes dm-delay: support zoned devices dm: restrict dm device size to 2^63-512 bytes dm cache: support shrinking the origin device dm cache: prevent BUG_ON by blocking retries on failed device resumes dm vdo indexer: reorder uds_request to reduce padding dm: fix unconditional IO throttle caused by REQ_PREFLUSH dm vdo: rework processing of loaded refcount byte arrays dm vdo: remove remaining ring references dm-verity: do forward error correction on metadata I/O errors dm-bufio: remove unused return value dm-integrity: set ti->error on memory allocation failure dm: Enable inline crypto passthrough for striped target dm vdo slab-depot: read refcount blocks in large chunks at load time dm vdo vio-pool: allow variable-sized metadata vios dm vdo vio-pool: support pools with multiple data blocks per vio dm vdo vio-pool: add a pool pointer to pooled_vio ...
Diffstat (limited to 'drivers/md/dm-cache-target.c')
-rw-r--r--drivers/md/dm-cache-target.c96
1 files changed, 93 insertions, 3 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 9cb797a561d6..a10d75a562db 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -406,6 +406,12 @@ struct cache {
mempool_t migration_pool;
struct bio_set bs;
+
+ /*
+ * Cache_size entries. Set bits indicate blocks mapped beyond the
+ * target length, which are marked for invalidation.
+ */
+ unsigned long *invalid_bitset;
};
struct per_bio_data {
@@ -1922,6 +1928,9 @@ static void __destroy(struct cache *cache)
if (cache->discard_bitset)
free_bitset(cache->discard_bitset);
+ if (cache->invalid_bitset)
+ free_bitset(cache->invalid_bitset);
+
if (cache->copier)
dm_kcopyd_client_destroy(cache->copier);
@@ -2510,6 +2519,13 @@ static int cache_create(struct cache_args *ca, struct cache **result)
}
clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks));
+ cache->invalid_bitset = alloc_bitset(from_cblock(cache->cache_size));
+ if (!cache->invalid_bitset) {
+ *error = "could not allocate bitset for invalid blocks";
+ goto bad;
+ }
+ clear_bitset(cache->invalid_bitset, from_cblock(cache->cache_size));
+
cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(cache->copier)) {
*error = "could not create kcopyd client";
@@ -2808,6 +2824,24 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
return policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid);
}
+static int load_filtered_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
+ bool dirty, uint32_t hint, bool hint_valid)
+{
+ struct cache *cache = context;
+
+ if (from_oblock(oblock) >= from_oblock(cache->origin_blocks)) {
+ if (dirty) {
+ DMERR("%s: unable to shrink origin; cache block %u is dirty",
+ cache_device_name(cache), from_cblock(cblock));
+ return -EFBIG;
+ }
+ set_bit(from_cblock(cblock), cache->invalid_bitset);
+ return 0;
+ }
+
+ return load_mapping(context, oblock, cblock, dirty, hint, hint_valid);
+}
+
/*
* The discard block size in the on disk metadata is not
* necessarily the same as we're currently using. So we have to
@@ -2899,6 +2933,27 @@ static dm_cblock_t get_cache_dev_size(struct cache *cache)
return to_cblock(size);
}
+static bool can_resume(struct cache *cache)
+{
+ /*
+ * Disallow retrying the resume operation for devices that failed the
+ * first resume attempt, as the failure leaves the policy object partially
+ * initialized. Retrying could trigger BUG_ON when loading cache mappings
+ * into the incomplete policy object.
+ */
+ if (cache->sized && !cache->loaded_mappings) {
+ if (get_cache_mode(cache) != CM_WRITE)
+ DMERR("%s: unable to resume a failed-loaded cache, please check metadata.",
+ cache_device_name(cache));
+ else
+ DMERR("%s: unable to resume cache due to missing proper cache table reload",
+ cache_device_name(cache));
+ return false;
+ }
+
+ return true;
+}
+
static bool can_resize(struct cache *cache, dm_cblock_t new_size)
{
if (from_cblock(new_size) > from_cblock(cache->cache_size)) {
@@ -2941,12 +2996,33 @@ static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size)
return 0;
}
+static int truncate_oblocks(struct cache *cache)
+{
+ uint32_t nr_blocks = from_cblock(cache->cache_size);
+ uint32_t i;
+ int r;
+
+ for_each_set_bit(i, cache->invalid_bitset, nr_blocks) {
+ r = dm_cache_remove_mapping(cache->cmd, to_cblock(i));
+ if (r) {
+ DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata",
+ cache_device_name(cache));
+ return r;
+ }
+ }
+
+ return 0;
+}
+
static int cache_preresume(struct dm_target *ti)
{
int r = 0;
struct cache *cache = ti->private;
dm_cblock_t csize = get_cache_dev_size(cache);
+ if (!can_resume(cache))
+ return -EINVAL;
+
/*
* Check to see if the cache has resized.
*/
@@ -2962,11 +3038,25 @@ static int cache_preresume(struct dm_target *ti)
}
if (!cache->loaded_mappings) {
+ /*
+ * The fast device could have been resized since the last
+ * failed preresume attempt. To be safe we start by a blank
+ * bitset for cache blocks.
+ */
+ clear_bitset(cache->invalid_bitset, from_cblock(cache->cache_size));
+
r = dm_cache_load_mappings(cache->cmd, cache->policy,
- load_mapping, cache);
+ load_filtered_mapping, cache);
if (r) {
DMERR("%s: could not load cache mappings", cache_device_name(cache));
- metadata_operation_failed(cache, "dm_cache_load_mappings", r);
+ if (r != -EFBIG)
+ metadata_operation_failed(cache, "dm_cache_load_mappings", r);
+ return r;
+ }
+
+ r = truncate_oblocks(cache);
+ if (r) {
+ metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
return r;
}
@@ -3426,7 +3516,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type cache_target = {
.name = "cache",
- .version = {2, 2, 0},
+ .version = {2, 3, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,