dm thin metadata: introduce dm_pool_abort_metadata
[deliverable/linux.git] / drivers / md / dm-thin-metadata.c
index 867ee52121d4746e3cbc6c7cd747f89590c6cfc5..693e149e97271dbe3fa3b646cfac018533892835 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Red Hat, Inc.
+ * Copyright (C) 2011-2012 Red Hat, Inc.
  *
  * This file is released under the GPL.
  */
@@ -184,6 +184,14 @@ struct dm_pool_metadata {
        uint64_t trans_id;
        unsigned long flags;
        sector_t data_block_size;
+       bool read_only:1;
+
+       /*
+        * Set if a transaction has to be aborted but the attempt to roll back
+        * to the previous (good) transaction failed.  The only pool metadata
+        * operation possible in this state is the closing of the device.
+        */
+       bool fail_io:1;
 };
 
 struct dm_thin_device {
@@ -192,7 +200,8 @@ struct dm_thin_device {
        dm_thin_id id;
 
        int open_count;
-       int changed;
+       bool changed:1;
+       bool aborted_with_changes:1;
        uint64_t mapped_blocks;
        uint64_t transaction_id;
        uint32_t creation_time;
@@ -500,37 +509,39 @@ static int __format_metadata(struct dm_pool_metadata *pmd)
        if (IS_ERR(pmd->data_sm)) {
                DMERR("sm_disk_create failed");
                r = PTR_ERR(pmd->data_sm);
-               goto bad;
+               goto bad_cleanup_tm;
        }
 
        pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
        if (!pmd->nb_tm) {
-               DMERR("could not create clone tm");
+               DMERR("could not create non-blocking clone tm");
                r = -ENOMEM;
-               goto bad_data_sm;
+               goto bad_cleanup_data_sm;
        }
 
        __setup_btree_details(pmd);
 
        r = dm_btree_empty(&pmd->info, &pmd->root);
        if (r < 0)
-               goto bad_data_sm;
+               goto bad_cleanup_nb_tm;
 
        r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
        if (r < 0) {
                DMERR("couldn't create devices root");
-               goto bad_data_sm;
+               goto bad_cleanup_nb_tm;
        }
 
        r = __write_initial_superblock(pmd);
        if (r)
-               goto bad_data_sm;
+               goto bad_cleanup_nb_tm;
 
        return 0;
 
-bad_data_sm:
+bad_cleanup_nb_tm:
+       dm_tm_destroy(pmd->nb_tm);
+bad_cleanup_data_sm:
        dm_sm_destroy(pmd->data_sm);
-bad:
+bad_cleanup_tm:
        dm_tm_destroy(pmd->tm);
        dm_sm_destroy(pmd->metadata_sm);
 
@@ -581,10 +592,8 @@ static int __open_metadata(struct dm_pool_metadata *pmd)
        disk_super = dm_block_data(sblock);
 
        r = __check_incompat_features(disk_super, pmd);
-       if (r < 0) {
-               dm_bm_unlock(sblock);
-               return r;
-       }
+       if (r < 0)
+               goto bad_unlock_sblock;
 
        r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
                               disk_super->metadata_space_map_root,
@@ -592,40 +601,39 @@ static int __open_metadata(struct dm_pool_metadata *pmd)
                               &pmd->tm, &pmd->metadata_sm);
        if (r < 0) {
                DMERR("tm_open_with_sm failed");
-               dm_bm_unlock(sblock);
-               return r;
+               goto bad_unlock_sblock;
        }
 
        pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
                                       sizeof(disk_super->data_space_map_root));
        if (IS_ERR(pmd->data_sm)) {
                DMERR("sm_disk_open failed");
-               dm_bm_unlock(sblock);
                r = PTR_ERR(pmd->data_sm);
-               goto bad;
+               goto bad_cleanup_tm;
        }
 
-       dm_bm_unlock(sblock);
-
        pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
        if (!pmd->nb_tm) {
-               DMERR("could not create clone tm");
+               DMERR("could not create non-blocking clone tm");
                r = -ENOMEM;
-               goto bad_data_sm;
+               goto bad_cleanup_data_sm;
        }
 
        __setup_btree_details(pmd);
+       return dm_bm_unlock(sblock);
 
-bad_data_sm:
+bad_cleanup_data_sm:
        dm_sm_destroy(pmd->data_sm);
-bad:
+bad_cleanup_tm:
        dm_tm_destroy(pmd->tm);
        dm_sm_destroy(pmd->metadata_sm);
+bad_unlock_sblock:
+       dm_bm_unlock(sblock);
 
        return r;
 }
 
-static int __open_or_format_metadata(struct dm_pool_metadata *pmd)
+static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
 {
        int r, unformatted;
 
@@ -634,12 +642,12 @@ static int __open_or_format_metadata(struct dm_pool_metadata *pmd)
                return r;
 
        if (unformatted)
-               return __format_metadata(pmd);
-       else
-               return __open_metadata(pmd);
+               return format_device ? __format_metadata(pmd) : -EPERM;
+
+       return __open_metadata(pmd);
 }
 
-static int __create_persistent_data_objects(struct dm_pool_metadata *pmd)
+static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
 {
        int r;
 
@@ -651,7 +659,7 @@ static int __create_persistent_data_objects(struct dm_pool_metadata *pmd)
                return PTR_ERR(pmd->bm);
        }
 
-       r = __open_or_format_metadata(pmd);
+       r = __open_or_format_metadata(pmd, format_device);
        if (r)
                dm_block_manager_destroy(pmd->bm);
 
@@ -731,9 +739,6 @@ static int __write_changed_details(struct dm_pool_metadata *pmd)
 
 static int __commit_transaction(struct dm_pool_metadata *pmd)
 {
-       /*
-        * FIXME: Associated pool should be made read-only on failure.
-        */
        int r;
        size_t metadata_len, data_len;
        struct thin_disk_superblock *disk_super;
@@ -793,7 +798,8 @@ out_locked:
 }
 
 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
-                                              sector_t data_block_size)
+                                              sector_t data_block_size,
+                                              bool format_device)
 {
        int r;
        struct dm_pool_metadata *pmd;
@@ -807,10 +813,12 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
        init_rwsem(&pmd->root_lock);
        pmd->time = 0;
        INIT_LIST_HEAD(&pmd->thin_devices);
+       pmd->read_only = false;
+       pmd->fail_io = false;
        pmd->bdev = bdev;
        pmd->data_block_size = data_block_size;
 
-       r = __create_persistent_data_objects(pmd);
+       r = __create_persistent_data_objects(pmd, format_device);
        if (r) {
                kfree(pmd);
                return ERR_PTR(r);
@@ -849,14 +857,17 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
                return -EBUSY;
        }
 
-       r = __commit_transaction(pmd);
-       if (r < 0)
-               DMWARN("%s: __commit_transaction() failed, error = %d",
-                      __func__, r);
+       if (!pmd->read_only && !pmd->fail_io) {
+               r = __commit_transaction(pmd);
+               if (r < 0)
+                       DMWARN("%s: __commit_transaction() failed, error = %d",
+                              __func__, r);
+       }
 
-       __destroy_persistent_data_objects(pmd);
-       kfree(pmd);
+       if (!pmd->fail_io)
+               __destroy_persistent_data_objects(pmd);
 
+       kfree(pmd);
        return 0;
 }
 
@@ -917,6 +928,7 @@ static int __open_device(struct dm_pool_metadata *pmd,
        (*td)->id = dev;
        (*td)->open_count = 1;
        (*td)->changed = changed;
+       (*td)->aborted_with_changes = false;
        (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
        (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
        (*td)->creation_time = le32_to_cpu(details_le.creation_time);
@@ -978,10 +990,11 @@ static int __create_thin(struct dm_pool_metadata *pmd,
 
 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __create_thin(pmd, dev);
+       if (!pmd->fail_io)
+               r = __create_thin(pmd, dev);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1068,10 +1081,11 @@ int dm_pool_create_snap(struct dm_pool_metadata *pmd,
                                 dm_thin_id dev,
                                 dm_thin_id origin)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __create_snap(pmd, dev, origin);
+       if (!pmd->fail_io)
+               r = __create_snap(pmd, dev, origin);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1110,10 +1124,11 @@ static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
                               dm_thin_id dev)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __delete_device(pmd, dev);
+       if (!pmd->fail_io)
+               r = __delete_device(pmd, dev);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1123,27 +1138,40 @@ int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
                                        uint64_t current_id,
                                        uint64_t new_id)
 {
+       int r = -EINVAL;
+
        down_write(&pmd->root_lock);
+
+       if (pmd->fail_io)
+               goto out;
+
        if (pmd->trans_id != current_id) {
-               up_write(&pmd->root_lock);
                DMERR("mismatched transaction id");
-               return -EINVAL;
+               goto out;
        }
 
        pmd->trans_id = new_id;
+       r = 0;
+
+out:
        up_write(&pmd->root_lock);
 
-       return 0;
+       return r;
 }
 
 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
                                        uint64_t *result)
 {
+       int r = -EINVAL;
+
        down_read(&pmd->root_lock);
-       *result = pmd->trans_id;
+       if (!pmd->fail_io) {
+               *result = pmd->trans_id;
+               r = 0;
+       }
        up_read(&pmd->root_lock);
 
-       return 0;
+       return r;
 }
 
 static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
@@ -1207,10 +1235,11 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
 
 int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __reserve_metadata_snap(pmd);
+       if (!pmd->fail_io)
+               r = __reserve_metadata_snap(pmd);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1252,10 +1281,11 @@ static int __release_metadata_snap(struct dm_pool_metadata *pmd)
 
 int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __release_metadata_snap(pmd);
+       if (!pmd->fail_io)
+               r = __release_metadata_snap(pmd);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1282,10 +1312,11 @@ static int __get_metadata_snap(struct dm_pool_metadata *pmd,
 int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
                              dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
 
        down_read(&pmd->root_lock);
-       r = __get_metadata_snap(pmd, result);
+       if (!pmd->fail_io)
+               r = __get_metadata_snap(pmd, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1294,10 +1325,11 @@ int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
                             struct dm_thin_device **td)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __open_device(pmd, dev, 0, td);
+       if (!pmd->fail_io)
+               r = __open_device(pmd, dev, 0, td);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1325,28 +1357,31 @@ static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
                       int can_block, struct dm_thin_lookup_result *result)
 {
-       int r;
+       int r = -EINVAL;
        uint64_t block_time = 0;
        __le64 value;
        struct dm_pool_metadata *pmd = td->pmd;
        dm_block_t keys[2] = { td->id, block };
+       struct dm_btree_info *info;
 
        if (can_block) {
                down_read(&pmd->root_lock);
-               r = dm_btree_lookup(&pmd->info, pmd->root, keys, &value);
-               if (!r)
-                       block_time = le64_to_cpu(value);
-               up_read(&pmd->root_lock);
-
-       } else if (down_read_trylock(&pmd->root_lock)) {
-               r = dm_btree_lookup(&pmd->nb_info, pmd->root, keys, &value);
-               if (!r)
-                       block_time = le64_to_cpu(value);
-               up_read(&pmd->root_lock);
-
-       } else
+               info = &pmd->info;
+       } else if (down_read_trylock(&pmd->root_lock))
+               info = &pmd->nb_info;
+       else
                return -EWOULDBLOCK;
 
+       if (pmd->fail_io)
+               goto out;
+
+       r = dm_btree_lookup(info, pmd->root, keys, &value);
+       if (!r)
+               block_time = le64_to_cpu(value);
+
+out:
+       up_read(&pmd->root_lock);
+
        if (!r) {
                dm_block_t exception_block;
                uint32_t exception_time;
@@ -1375,10 +1410,9 @@ static int __insert(struct dm_thin_device *td, dm_block_t block,
        if (r)
                return r;
 
-       if (inserted) {
+       td->changed = 1;
+       if (inserted)
                td->mapped_blocks++;
-               td->changed = 1;
-       }
 
        return 0;
 }
@@ -1386,10 +1420,11 @@ static int __insert(struct dm_thin_device *td, dm_block_t block,
 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
                         dm_block_t data_block)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&td->pmd->root_lock);
-       r = __insert(td, block, data_block);
+       if (!td->pmd->fail_io)
+               r = __insert(td, block, data_block);
        up_write(&td->pmd->root_lock);
 
        return r;
@@ -1413,21 +1448,45 @@ static int __remove(struct dm_thin_device *td, dm_block_t block)
 
 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&td->pmd->root_lock);
-       r = __remove(td, block);
+       if (!td->pmd->fail_io)
+               r = __remove(td, block);
        up_write(&td->pmd->root_lock);
 
        return r;
 }
 
-int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
+bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
 {
        int r;
 
+       down_read(&td->pmd->root_lock);
+       r = td->changed;
+       up_read(&td->pmd->root_lock);
+
+       return r;
+}
+
+bool dm_thin_aborted_changes(struct dm_thin_device *td)
+{
+       bool r;
+
+       down_read(&td->pmd->root_lock);
+       r = td->aborted_with_changes;
+       up_read(&td->pmd->root_lock);
+
+       return r;
+}
+
+int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
+{
+       int r = -EINVAL;
+
        down_write(&pmd->root_lock);
-       r = dm_sm_new_block(pmd->data_sm, result);
+       if (!pmd->fail_io)
+               r = dm_sm_new_block(pmd->data_sm, result);
        up_write(&pmd->root_lock);
 
        return r;
@@ -1435,9 +1494,11 @@ int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
 
 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
+       if (pmd->fail_io)
+               goto out;
 
        r = __commit_transaction(pmd);
        if (r <= 0)
@@ -1452,12 +1513,41 @@ out:
        return r;
 }
 
+static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
+{
+       struct dm_thin_device *td;
+
+       list_for_each_entry(td, &pmd->thin_devices, list)
+               td->aborted_with_changes = td->changed;
+}
+
+int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
+{
+       int r = -EINVAL;
+
+       down_write(&pmd->root_lock);
+       if (pmd->fail_io)
+               goto out;
+
+       __set_abort_with_changes_flags(pmd);
+       __destroy_persistent_data_objects(pmd);
+       r = __create_persistent_data_objects(pmd, false);
+       if (r)
+               pmd->fail_io = true;
+
+out:
+       up_write(&pmd->root_lock);
+
+       return r;
+}
+
 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
 
        down_read(&pmd->root_lock);
-       r = dm_sm_get_nr_free(pmd->data_sm, result);
+       if (!pmd->fail_io)
+               r = dm_sm_get_nr_free(pmd->data_sm, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1466,10 +1556,11 @@ int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *resul
 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
                                          dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
 
        down_read(&pmd->root_lock);
-       r = dm_sm_get_nr_free(pmd->metadata_sm, result);
+       if (!pmd->fail_io)
+               r = dm_sm_get_nr_free(pmd->metadata_sm, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1478,10 +1569,11 @@ int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
                                  dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
 
        down_read(&pmd->root_lock);
-       r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
+       if (!pmd->fail_io)
+               r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1498,10 +1590,11 @@ int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result)
 
 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
 
        down_read(&pmd->root_lock);
-       r = dm_sm_get_nr_blocks(pmd->data_sm, result);
+       if (!pmd->fail_io)
+               r = dm_sm_get_nr_blocks(pmd->data_sm, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1509,13 +1602,17 @@ int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
 
 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
 {
+       int r = -EINVAL;
        struct dm_pool_metadata *pmd = td->pmd;
 
        down_read(&pmd->root_lock);
-       *result = td->mapped_blocks;
+       if (!pmd->fail_io) {
+               *result = td->mapped_blocks;
+               r = 0;
+       }
        up_read(&pmd->root_lock);
 
-       return 0;
+       return r;
 }
 
 static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
@@ -1537,11 +1634,12 @@ static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
                                     dm_block_t *result)
 {
-       int r;
+       int r = -EINVAL;
        struct dm_pool_metadata *pmd = td->pmd;
 
        down_read(&pmd->root_lock);
-       r = __highest_block(td, result);
+       if (!pmd->fail_io)
+               r = __highest_block(td, result);
        up_read(&pmd->root_lock);
 
        return r;
@@ -1569,11 +1667,20 @@ static int __resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
 
 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
 {
-       int r;
+       int r = -EINVAL;
 
        down_write(&pmd->root_lock);
-       r = __resize_data_dev(pmd, new_count);
+       if (!pmd->fail_io)
+               r = __resize_data_dev(pmd, new_count);
        up_write(&pmd->root_lock);
 
        return r;
 }
+
+void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
+{
+       down_write(&pmd->root_lock);
+       pmd->read_only = true;
+       dm_bm_set_read_only(pmd->bm);
+       up_write(&pmd->root_lock);
+}
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