Merge tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / drivers / md / dm-thin-metadata.c
index d30bc09fd7c4d81814adeca46df29d2eb11b9b53..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.
  */
@@ -185,6 +185,13 @@ struct dm_pool_metadata {
        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 {
@@ -193,7 +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;
@@ -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;
@@ -809,6 +814,7 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
        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;
 
@@ -851,16 +857,17 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
                return -EBUSY;
        }
 
-       if (!pmd->read_only) {
+       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;
 }
 
@@ -921,6 +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);
@@ -982,10 +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;
@@ -1072,10 +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;
@@ -1114,10 +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;
@@ -1127,27 +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)
@@ -1211,10 +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;
@@ -1256,10 +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;
@@ -1286,10 +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;
@@ -1298,10 +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;
@@ -1329,28 +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;
@@ -1389,10 +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;
@@ -1416,10 +1448,11 @@ 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;
@@ -1436,12 +1469,24 @@ bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
        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;
+       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;
@@ -1449,9 +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)
@@ -1466,12 +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;
@@ -1480,10 +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;
@@ -1492,10 +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;
@@ -1512,10 +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;
@@ -1523,13 +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)
@@ -1551,11 +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;
@@ -1583,10 +1667,11 @@ 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;
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