Merge tag 'dm-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 13 Dec 2013 21:22:22 +0000 (13:22 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 13 Dec 2013 21:22:22 +0000 (13:22 -0800)
Pull device mapper fixes from Mike Snitzer:
 "A set of device-mapper fixes for 3.13.

  A fix for possible memory corruption during DM table load, fix a
  possible leak of snapshot space in case of a crash, fix a possible
  deadlock due to a shared workqueue in the delay target, fix to
  initialize read-only module parameters that are used to export metrics
  for dm stats and dm bufio.

  Quite a few stable fixes were identified for both the thin-
  provisioning and caching targets as a result of increased regression
  testing using the device-mapper-test-suite (dmts).  The most notable
  of these are the reference counting fixes for the space map btree that
  is used by the dm-array interface -- without these the dm-cache
  metadata will leak, resulting in dm-cache devices running out of
  metadata blocks.  Also, some important fixes related to the
  thin-provisioning target's transition to read-only mode on error"

* tag 'dm-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm array: fix a reference counting bug in shadow_ablock
  dm space map: disallow decrementing a reference count below zero
  dm stats: initialize read-only module parameter
  dm bufio: initialize read-only module parameters
  dm cache: actually resize cache
  dm cache: update Documentation for invalidate_cblocks's range syntax
  dm cache policy mq: fix promotions to occur as expected
  dm thin: allow pool in read-only mode to transition to read-write mode
  dm thin: re-establish read-only state when switching to fail mode
  dm thin: always fallback the pool mode if commit fails
  dm thin: switch to read-only mode if metadata space is exhausted
  dm thin: switch to read only mode if a mapping insert fails
  dm space map metadata: return on failure in sm_metadata_new_block
  dm table: fail dm_table_create on dm_round_up overflow
  dm snapshot: avoid snapshot space leak on crash
  dm delay: fix a possible deadlock due to shared workqueue

16 files changed:
Documentation/device-mapper/cache.txt
drivers/md/dm-bufio.c
drivers/md/dm-cache-policy-mq.c
drivers/md/dm-cache-target.c
drivers/md/dm-delay.c
drivers/md/dm-snap.c
drivers/md/dm-stats.c
drivers/md/dm-table.c
drivers/md/dm-thin-metadata.c
drivers/md/dm-thin-metadata.h
drivers/md/dm-thin.c
drivers/md/persistent-data/dm-array.c
drivers/md/persistent-data/dm-block-manager.c
drivers/md/persistent-data/dm-block-manager.h
drivers/md/persistent-data/dm-space-map-common.c
drivers/md/persistent-data/dm-space-map-metadata.c

index 274752f8bdf963b0f1757f2df446f6c5a503c6a5..719320b5ed3f36f476bd019781b774c3b4b8ace6 100644 (file)
@@ -266,10 +266,12 @@ E.g.
 Invalidation is removing an entry from the cache without writing it
 back.  Cache blocks can be invalidated via the invalidate_cblocks
 message, which takes an arbitrary number of cblock ranges.  Each cblock
-must be expressed as a decimal value, in the future a variant message
-that takes cblock ranges expressed in hexidecimal may be needed to
-better support efficient invalidation of larger caches.  The cache must
-be in passthrough mode when invalidate_cblocks is used.
+range's end value is "one past the end", meaning 5-10 expresses a range
+of values from 5 to 9.  Each cblock must be expressed as a decimal
+value, in the future a variant message that takes cblock ranges
+expressed in hexidecimal may be needed to better support efficient
+invalidation of larger caches.  The cache must be in passthrough mode
+when invalidate_cblocks is used.
 
    invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]*
 
index 173cbb20d10498b21440ada78b27f241b47af2cc..54bdd923316f92818d509f06986c9a9a3b7b1927 100644 (file)
@@ -1717,6 +1717,11 @@ static int __init dm_bufio_init(void)
 {
        __u64 mem;
 
+       dm_bufio_allocated_kmem_cache = 0;
+       dm_bufio_allocated_get_free_pages = 0;
+       dm_bufio_allocated_vmalloc = 0;
+       dm_bufio_current_allocated = 0;
+
        memset(&dm_bufio_caches, 0, sizeof dm_bufio_caches);
        memset(&dm_bufio_cache_names, 0, sizeof dm_bufio_cache_names);
 
index 416b7b752a6e0018d4a11800606a8be6b8890e22..64780ad73bb01737a957ea9682d016da4dbffa93 100644 (file)
@@ -730,15 +730,18 @@ static int pre_cache_entry_found(struct mq_policy *mq, struct entry *e,
        int r = 0;
        bool updated = updated_this_tick(mq, e);
 
-       requeue_and_update_tick(mq, e);
-
        if ((!discarded_oblock && updated) ||
-           !should_promote(mq, e, discarded_oblock, data_dir))
+           !should_promote(mq, e, discarded_oblock, data_dir)) {
+               requeue_and_update_tick(mq, e);
                result->op = POLICY_MISS;
-       else if (!can_migrate)
+
+       } else if (!can_migrate)
                r = -EWOULDBLOCK;
-       else
+
+       else {
+               requeue_and_update_tick(mq, e);
                r = pre_cache_to_cache(mq, e, result);
+       }
 
        return r;
 }
index 9efcf1059b99e3ae2e6e712eb150c0954646d5d8..1b1469ebe5cbad66af0853e0766ba20dbee63275 100644 (file)
@@ -2755,7 +2755,7 @@ static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size)
 {
        int r;
 
-       r = dm_cache_resize(cache->cmd, cache->cache_size);
+       r = dm_cache_resize(cache->cmd, new_size);
        if (r) {
                DMERR("could not resize cache metadata");
                return r;
index 496d5f3646a5df623e6c0a9b22d35ad003c610bc..2f91d6d4a2ccf40023c6bccfe142d7781024c810 100644 (file)
@@ -20,6 +20,7 @@
 struct delay_c {
        struct timer_list delay_timer;
        struct mutex timer_lock;
+       struct workqueue_struct *kdelayd_wq;
        struct work_struct flush_expired_bios;
        struct list_head delayed_bios;
        atomic_t may_delay;
@@ -45,14 +46,13 @@ struct dm_delay_info {
 
 static DEFINE_MUTEX(delayed_bios_lock);
 
-static struct workqueue_struct *kdelayd_wq;
 static struct kmem_cache *delayed_cache;
 
 static void handle_delayed_timer(unsigned long data)
 {
        struct delay_c *dc = (struct delay_c *)data;
 
-       queue_work(kdelayd_wq, &dc->flush_expired_bios);
+       queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);
 }
 
 static void queue_timeout(struct delay_c *dc, unsigned long expires)
@@ -191,6 +191,12 @@ out:
                goto bad_dev_write;
        }
 
+       dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
+       if (!dc->kdelayd_wq) {
+               DMERR("Couldn't start kdelayd");
+               goto bad_queue;
+       }
+
        setup_timer(&dc->delay_timer, handle_delayed_timer, (unsigned long)dc);
 
        INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
@@ -203,6 +209,8 @@ out:
        ti->private = dc;
        return 0;
 
+bad_queue:
+       mempool_destroy(dc->delayed_pool);
 bad_dev_write:
        if (dc->dev_write)
                dm_put_device(ti, dc->dev_write);
@@ -217,7 +225,7 @@ static void delay_dtr(struct dm_target *ti)
 {
        struct delay_c *dc = ti->private;
 
-       flush_workqueue(kdelayd_wq);
+       destroy_workqueue(dc->kdelayd_wq);
 
        dm_put_device(ti, dc->dev_read);
 
@@ -350,12 +358,6 @@ static int __init dm_delay_init(void)
 {
        int r = -ENOMEM;
 
-       kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
-       if (!kdelayd_wq) {
-               DMERR("Couldn't start kdelayd");
-               goto bad_queue;
-       }
-
        delayed_cache = KMEM_CACHE(dm_delay_info, 0);
        if (!delayed_cache) {
                DMERR("Couldn't create delayed bio cache.");
@@ -373,8 +375,6 @@ static int __init dm_delay_init(void)
 bad_register:
        kmem_cache_destroy(delayed_cache);
 bad_memcache:
-       destroy_workqueue(kdelayd_wq);
-bad_queue:
        return r;
 }
 
@@ -382,7 +382,6 @@ static void __exit dm_delay_exit(void)
 {
        dm_unregister_target(&delay_target);
        kmem_cache_destroy(delayed_cache);
-       destroy_workqueue(kdelayd_wq);
 }
 
 /* Module hooks */
index aec57d76db5d616c8e692fa95cee58a8f62a0573..944690bafd93241d9348f0a4f1cad7f917ce7d83 100644 (file)
@@ -66,6 +66,18 @@ struct dm_snapshot {
 
        atomic_t pending_exceptions_count;
 
+       /* Protected by "lock" */
+       sector_t exception_start_sequence;
+
+       /* Protected by kcopyd single-threaded callback */
+       sector_t exception_complete_sequence;
+
+       /*
+        * A list of pending exceptions that completed out of order.
+        * Protected by kcopyd single-threaded callback.
+        */
+       struct list_head out_of_order_list;
+
        mempool_t *pending_pool;
 
        struct dm_exception_table pending;
@@ -173,6 +185,14 @@ struct dm_snap_pending_exception {
         */
        int started;
 
+       /* There was copying error. */
+       int copy_error;
+
+       /* A sequence number, it is used for in-order completion. */
+       sector_t exception_sequence;
+
+       struct list_head out_of_order_entry;
+
        /*
         * For writing a complete chunk, bypassing the copy.
         */
@@ -1094,6 +1114,9 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        s->valid = 1;
        s->active = 0;
        atomic_set(&s->pending_exceptions_count, 0);
+       s->exception_start_sequence = 0;
+       s->exception_complete_sequence = 0;
+       INIT_LIST_HEAD(&s->out_of_order_list);
        init_rwsem(&s->lock);
        INIT_LIST_HEAD(&s->list);
        spin_lock_init(&s->pe_lock);
@@ -1443,6 +1466,19 @@ static void commit_callback(void *context, int success)
        pending_complete(pe, success);
 }
 
+static void complete_exception(struct dm_snap_pending_exception *pe)
+{
+       struct dm_snapshot *s = pe->snap;
+
+       if (unlikely(pe->copy_error))
+               pending_complete(pe, 0);
+
+       else
+               /* Update the metadata if we are persistent */
+               s->store->type->commit_exception(s->store, &pe->e,
+                                                commit_callback, pe);
+}
+
 /*
  * Called when the copy I/O has finished.  kcopyd actually runs
  * this code so don't block.
@@ -1452,13 +1488,32 @@ static void copy_callback(int read_err, unsigned long write_err, void *context)
        struct dm_snap_pending_exception *pe = context;
        struct dm_snapshot *s = pe->snap;
 
-       if (read_err || write_err)
-               pending_complete(pe, 0);
+       pe->copy_error = read_err || write_err;
 
-       else
-               /* Update the metadata if we are persistent */
-               s->store->type->commit_exception(s->store, &pe->e,
-                                                commit_callback, pe);
+       if (pe->exception_sequence == s->exception_complete_sequence) {
+               s->exception_complete_sequence++;
+               complete_exception(pe);
+
+               while (!list_empty(&s->out_of_order_list)) {
+                       pe = list_entry(s->out_of_order_list.next,
+                                       struct dm_snap_pending_exception, out_of_order_entry);
+                       if (pe->exception_sequence != s->exception_complete_sequence)
+                               break;
+                       s->exception_complete_sequence++;
+                       list_del(&pe->out_of_order_entry);
+                       complete_exception(pe);
+               }
+       } else {
+               struct list_head *lh;
+               struct dm_snap_pending_exception *pe2;
+
+               list_for_each_prev(lh, &s->out_of_order_list) {
+                       pe2 = list_entry(lh, struct dm_snap_pending_exception, out_of_order_entry);
+                       if (pe2->exception_sequence < pe->exception_sequence)
+                               break;
+               }
+               list_add(&pe->out_of_order_entry, lh);
+       }
 }
 
 /*
@@ -1553,6 +1608,8 @@ __find_pending_exception(struct dm_snapshot *s,
                return NULL;
        }
 
+       pe->exception_sequence = s->exception_start_sequence++;
+
        dm_insert_exception(&s->pending, &pe->e);
 
        return pe;
@@ -2192,7 +2249,7 @@ static struct target_type origin_target = {
 
 static struct target_type snapshot_target = {
        .name    = "snapshot",
-       .version = {1, 11, 1},
+       .version = {1, 12, 0},
        .module  = THIS_MODULE,
        .ctr     = snapshot_ctr,
        .dtr     = snapshot_dtr,
index 3d404c1371ed2d7e6f4fa052fd4379fbc89ec388..28a90122a5a89272f5873ed0911d2de19125c15b 100644 (file)
@@ -964,6 +964,7 @@ int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
 
 int __init dm_statistics_init(void)
 {
+       shared_memory_amount = 0;
        dm_stat_need_rcu_barrier = 0;
        return 0;
 }
index 465f08ca62b1e355f8fd776fac4a6159d79a1a2e..3ba6a3859ce3c4957439ff3afdc4a5133bc2900b 100644 (file)
@@ -200,6 +200,11 @@ int dm_table_create(struct dm_table **result, fmode_t mode,
 
        num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 
+       if (!num_targets) {
+               kfree(t);
+               return -ENOMEM;
+       }
+
        if (alloc_targets(t, num_targets)) {
                kfree(t);
                return -ENOMEM;
index 60bce435f4fa1443c2994bd483e70ea096c7aa92..8a30ad54bd46aabc72f4ac1800890b5bd8041e11 100644 (file)
@@ -1697,6 +1697,14 @@ void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
        up_write(&pmd->root_lock);
 }
 
+void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
+{
+       down_write(&pmd->root_lock);
+       pmd->read_only = false;
+       dm_bm_set_read_write(pmd->bm);
+       up_write(&pmd->root_lock);
+}
+
 int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
                                        dm_block_t threshold,
                                        dm_sm_threshold_fn fn,
index 845ebbe589a9e0a00505bab0150df48331233928..7bcc0e1d62386768d540c41da8e0a25bf7fe9e78 100644 (file)
@@ -193,6 +193,7 @@ int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_siz
  * that nothing is changing.
  */
 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd);
+void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd);
 
 int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
                                        dm_block_t threshold,
index 2c0cf511ec2385fa5a558b5d2e1e1ed0c874c9f6..ee29037ffc2e74633050b708718ccbe963bf20d1 100644 (file)
@@ -640,7 +640,9 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
         */
        r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
        if (r) {
-               DMERR_LIMIT("dm_thin_insert_block() failed");
+               DMERR_LIMIT("%s: dm_thin_insert_block() failed: error = %d",
+                           dm_device_name(pool->pool_md), r);
+               set_pool_mode(pool, PM_READ_ONLY);
                cell_error(pool, m->cell);
                goto out;
        }
@@ -881,32 +883,23 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
        }
 }
 
-static int commit(struct pool *pool)
-{
-       int r;
-
-       r = dm_pool_commit_metadata(pool->pmd);
-       if (r)
-               DMERR_LIMIT("%s: commit failed: error = %d",
-                           dm_device_name(pool->pool_md), r);
-
-       return r;
-}
-
 /*
  * A non-zero return indicates read_only or fail_io mode.
  * Many callers don't care about the return value.
  */
-static int commit_or_fallback(struct pool *pool)
+static int commit(struct pool *pool)
 {
        int r;
 
        if (get_pool_mode(pool) != PM_WRITE)
                return -EINVAL;
 
-       r = commit(pool);
-       if (r)
+       r = dm_pool_commit_metadata(pool->pmd);
+       if (r) {
+               DMERR_LIMIT("%s: dm_pool_commit_metadata failed: error = %d",
+                           dm_device_name(pool->pool_md), r);
                set_pool_mode(pool, PM_READ_ONLY);
+       }
 
        return r;
 }
@@ -943,7 +936,9 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
                 * Try to commit to see if that will free up some
                 * more space.
                 */
-               (void) commit_or_fallback(pool);
+               r = commit(pool);
+               if (r)
+                       return r;
 
                r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
                if (r)
@@ -957,7 +952,7 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
                 * table reload).
                 */
                if (!free_blocks) {
-                       DMWARN("%s: no free space available.",
+                       DMWARN("%s: no free data space available.",
                               dm_device_name(pool->pool_md));
                        spin_lock_irqsave(&pool->lock, flags);
                        pool->no_free_space = 1;
@@ -967,8 +962,16 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
        }
 
        r = dm_pool_alloc_data_block(pool->pmd, result);
-       if (r)
+       if (r) {
+               if (r == -ENOSPC &&
+                   !dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks) &&
+                   !free_blocks) {
+                       DMWARN("%s: no free metadata space available.",
+                              dm_device_name(pool->pool_md));
+                       set_pool_mode(pool, PM_READ_ONLY);
+               }
                return r;
+       }
 
        return 0;
 }
@@ -1349,7 +1352,7 @@ static void process_deferred_bios(struct pool *pool)
        if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
                return;
 
-       if (commit_or_fallback(pool)) {
+       if (commit(pool)) {
                while ((bio = bio_list_pop(&bios)))
                        bio_io_error(bio);
                return;
@@ -1397,6 +1400,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode)
        case PM_FAIL:
                DMERR("%s: switching pool to failure mode",
                      dm_device_name(pool->pool_md));
+               dm_pool_metadata_read_only(pool->pmd);
                pool->process_bio = process_bio_fail;
                pool->process_discard = process_bio_fail;
                pool->process_prepared_mapping = process_prepared_mapping_fail;
@@ -1421,6 +1425,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode)
                break;
 
        case PM_WRITE:
+               dm_pool_metadata_read_write(pool->pmd);
                pool->process_bio = process_bio;
                pool->process_discard = process_discard;
                pool->process_prepared_mapping = process_prepared_mapping;
@@ -1637,12 +1642,19 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti)
        struct pool_c *pt = ti->private;
 
        /*
-        * We want to make sure that degraded pools are never upgraded.
+        * We want to make sure that a pool in PM_FAIL mode is never upgraded.
         */
        enum pool_mode old_mode = pool->pf.mode;
        enum pool_mode new_mode = pt->adjusted_pf.mode;
 
-       if (old_mode > new_mode)
+       /*
+        * If we were in PM_FAIL mode, rollback of metadata failed.  We're
+        * not going to recover without a thin_repair.  So we never let the
+        * pool move out of the old mode.  On the other hand a PM_READ_ONLY
+        * may have been due to a lack of metadata or data space, and may
+        * now work (ie. if the underlying devices have been resized).
+        */
+       if (old_mode == PM_FAIL)
                new_mode = old_mode;
 
        pool->ti = ti;
@@ -2266,7 +2278,7 @@ static int pool_preresume(struct dm_target *ti)
                return r;
 
        if (need_commit1 || need_commit2)
-               (void) commit_or_fallback(pool);
+               (void) commit(pool);
 
        return 0;
 }
@@ -2293,7 +2305,7 @@ static void pool_postsuspend(struct dm_target *ti)
 
        cancel_delayed_work(&pool->waker);
        flush_workqueue(pool->wq);
-       (void) commit_or_fallback(pool);
+       (void) commit(pool);
 }
 
 static int check_arg_count(unsigned argc, unsigned args_required)
@@ -2427,7 +2439,7 @@ static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct
        if (r)
                return r;
 
-       (void) commit_or_fallback(pool);
+       (void) commit(pool);
 
        r = dm_pool_reserve_metadata_snap(pool->pmd);
        if (r)
@@ -2489,7 +2501,7 @@ static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
                DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
 
        if (!r)
-               (void) commit_or_fallback(pool);
+               (void) commit(pool);
 
        return r;
 }
@@ -2544,7 +2556,7 @@ static void pool_status(struct dm_target *ti, status_type_t type,
 
                /* Commit to ensure statistics aren't out-of-date */
                if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
-                       (void) commit_or_fallback(pool);
+                       (void) commit(pool);
 
                r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
                if (r) {
index af96e24ec3280ff9c29a7b7f13fde6fc4ba43e52..1d75b1dc1e2e2fcdd24a3be8cf9f0168efacd51e 100644 (file)
@@ -317,8 +317,16 @@ static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
         * The shadow op will often be a noop.  Only insert if it really
         * copied data.
         */
-       if (dm_block_location(*block) != b)
+       if (dm_block_location(*block) != b) {
+               /*
+                * dm_tm_shadow_block will have already decremented the old
+                * block, but it is still referenced by the btree.  We
+                * increment to stop the insert decrementing it below zero
+                * when overwriting the old value.
+                */
+               dm_tm_inc(info->btree_info.tm, b);
                r = insert_ablock(info, index, *block, root);
+       }
 
        return r;
 }
index a7e8bf2963886dfa349a03644cf33ff1ded748c5..064a3c271baa8843657dca3c374ed89061565ad4 100644 (file)
@@ -626,6 +626,12 @@ void dm_bm_set_read_only(struct dm_block_manager *bm)
 }
 EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
 
+void dm_bm_set_read_write(struct dm_block_manager *bm)
+{
+       bm->read_only = false;
+}
+EXPORT_SYMBOL_GPL(dm_bm_set_read_write);
+
 u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor)
 {
        return crc32c(~(u32) 0, data, len) ^ init_xor;
index 9a82083a66b6a86833bccc1d2b6d4d43c9de6500..13cd58e1fe69ffb4ed477b10ee6bbbe6d58d9926 100644 (file)
@@ -108,9 +108,9 @@ int dm_bm_unlock(struct dm_block *b);
 int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
                           struct dm_block *superblock);
 
- /*
 * Request data be prefetched into the cache.
 */
+/*
* Request data is prefetched into the cache.
+ */
 void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
 
 /*
@@ -125,6 +125,7 @@ void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
  * be returned if you do.
  */
 void dm_bm_set_read_only(struct dm_block_manager *bm);
+void dm_bm_set_read_write(struct dm_block_manager *bm);
 
 u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor);
 
index 6058569fe86c3dcf862ddc933e234e721dbdc3e6..466a60bbd716f6470d1e4004ac217c3f546f5c81 100644 (file)
@@ -381,7 +381,7 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 }
 
 static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
-                       uint32_t (*mutator)(void *context, uint32_t old),
+                       int (*mutator)(void *context, uint32_t old, uint32_t *new),
                        void *context, enum allocation_event *ev)
 {
        int r;
@@ -410,11 +410,17 @@ static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
 
        if (old > 2) {
                r = sm_ll_lookup_big_ref_count(ll, b, &old);
-               if (r < 0)
+               if (r < 0) {
+                       dm_tm_unlock(ll->tm, nb);
                        return r;
+               }
        }
 
-       ref_count = mutator(context, old);
+       r = mutator(context, old, &ref_count);
+       if (r) {
+               dm_tm_unlock(ll->tm, nb);
+               return r;
+       }
 
        if (ref_count <= 2) {
                sm_set_bitmap(bm_le, bit, ref_count);
@@ -465,9 +471,10 @@ static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
        return ll->save_ie(ll, index, &ie_disk);
 }
 
-static uint32_t set_ref_count(void *context, uint32_t old)
+static int set_ref_count(void *context, uint32_t old, uint32_t *new)
 {
-       return *((uint32_t *) context);
+       *new = *((uint32_t *) context);
+       return 0;
 }
 
 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
@@ -476,9 +483,10 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
        return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
 }
 
-static uint32_t inc_ref_count(void *context, uint32_t old)
+static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
 {
-       return old + 1;
+       *new = old + 1;
+       return 0;
 }
 
 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
@@ -486,9 +494,15 @@ int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
        return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
 }
 
-static uint32_t dec_ref_count(void *context, uint32_t old)
+static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
 {
-       return old - 1;
+       if (!old) {
+               DMERR_LIMIT("unable to decrement a reference count below 0");
+               return -EINVAL;
+       }
+
+       *new = old - 1;
+       return 0;
 }
 
 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
index 1c959684caef7512fafd3c1a5505c29c798a9c11..58fc1eef7499e1923ef00095502c1e1b49f50ffb 100644 (file)
@@ -384,12 +384,16 @@ static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
        struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 
        int r = sm_metadata_new_block_(sm, b);
-       if (r)
+       if (r) {
                DMERR("unable to allocate new metadata block");
+               return r;
+       }
 
        r = sm_metadata_get_nr_free(sm, &count);
-       if (r)
+       if (r) {
                DMERR("couldn't get free block count");
+               return r;
+       }
 
        check_threshold(&smm->threshold, count);