Otherwise, just loading a thin-pool and then removing it will cause its
metadata to be changed (e.g. superblock written) -- even without any
thin devices being made active or metadata snapshot being manipulated.
Add 'changed' flag to struct dm_pool_metadata. Set both td->changed and
pmd->changed using __set_thin_changed() -- this assures pmd->changed is
always set when td->changed is. For methods that don't involve changing
a td, set pmd->changed directly.
Rename __delete_device() to __delete_thin() -- improves symmetry with
__create_thin().
Update dm_pool_changed_this_transaction() to simply return pmd->changed.
Fix dm_pool_commit_metadata() to open the next transaction if the return
from __commit_transaction() is 0. Not seeing why the early return ever
made since for a return of 0 given that dm-io's async_io(), as used by
bufio, always returns 0.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-thin-metadata.c | 56 ++++++++++++++++++++++++-----------
1 file changed, 39 insertions(+), 17 deletions(-)
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index ed3caceaed07..f4e8327abc75 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -201,6 +201,12 @@ struct dm_pool_metadata {
*/
bool fail_io:1;
+ /*
+ * Set if metadata has changed, particularly important for methods that
+ * alter metadata without the ability to reflect the change in td->changed.
+ */
+ bool changed:1;
+
/*
* Reading the space map roots can fail, so we read it into these
* buffers before the superblock is locked and updated.
@@ -769,7 +775,7 @@ static int __write_changed_details(struct dm_pool_metadata *pmd)
return r;
if (td->open_count)
- td->changed = 0;
+ td->changed = false;
else {
list_del(&td->list);
kfree(td);
@@ -779,6 +785,14 @@ static int __write_changed_details(struct dm_pool_metadata *pmd)
return 0;
}
+static void __set_thin_changed(struct dm_thin_device *td)
+{
+ struct dm_pool_metadata *pmd = td->pmd;
+
+ td->changed = true;
+ pmd->changed = true;
+}
+
static int __commit_transaction(struct dm_pool_metadata *pmd)
{
int r;
@@ -790,6 +804,9 @@ static int __commit_transaction(struct dm_pool_metadata *pmd)
*/
BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
+ if (!pmd->changed)
+ return 0;
+
r = __write_changed_details(pmd);
if (r < 0)
return r;
@@ -819,6 +836,8 @@ static int __commit_transaction(struct dm_pool_metadata *pmd)
copy_sm_roots(pmd, disk_super);
+ pmd->changed = false;
+
return dm_tm_commit(pmd->tm, sblock);
}
@@ -853,6 +872,7 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
pmd->time = 0;
INIT_LIST_HEAD(&pmd->thin_devices);
pmd->fail_io = false;
+ pmd->changed = false;
pmd->bdev = bdev;
pmd->data_block_size = data_block_size;
@@ -967,7 +987,8 @@ static int __open_device(struct dm_pool_metadata *pmd,
(*td)->pmd = pmd;
(*td)->id = dev;
(*td)->open_count = 1;
- (*td)->changed = changed;
+ if (changed)
+ __set_thin_changed(*td);
(*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);
@@ -1051,7 +1072,7 @@ static int __set_snapshot_details(struct dm_pool_metadata *pmd,
if (r)
return r;
- td->changed = 1;
+ __set_thin_changed(td);
td->snapshotted_time = time;
snap->mapped_blocks = td->mapped_blocks;
@@ -1131,7 +1152,7 @@ int dm_pool_create_snap(struct dm_pool_metadata *pmd,
return r;
}
-static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
+static int __delete_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
{
int r;
uint64_t key = dev;
@@ -1158,6 +1179,8 @@ static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
if (r)
return r;
+ pmd->changed = true;
+
return 0;
}
@@ -1168,7 +1191,7 @@ int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
down_write(&pmd->root_lock);
if (!pmd->fail_io)
- r = __delete_device(pmd, dev);
+ r = __delete_thin(pmd, dev);
up_write(&pmd->root_lock);
return r;
@@ -1276,6 +1299,9 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
disk_super = dm_block_data(sblock);
disk_super->held_root = cpu_to_le64(held_root);
dm_bm_unlock(sblock);
+
+ pmd->changed = true;
+
return 0;
}
@@ -1324,6 +1350,8 @@ static int __release_metadata_snap(struct dm_pool_metadata *pmd)
dm_tm_unlock(pmd->tm, copy);
+ pmd->changed = true;
+
return 0;
}
@@ -1558,7 +1586,7 @@ static int __insert(struct dm_thin_device *td, dm_block_t block,
if (r)
return r;
- td->changed = 1;
+ __set_thin_changed(td);
if (inserted)
td->mapped_blocks++;
@@ -1589,7 +1617,7 @@ static int __remove(struct dm_thin_device *td, dm_block_t block)
return r;
td->mapped_blocks--;
- td->changed = 1;
+ __set_thin_changed(td);
return 0;
}
@@ -1643,7 +1671,7 @@ static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_
}
td->mapped_blocks -= total_count;
- td->changed = 1;
+ __set_thin_changed(td);
/*
* Reinsert the mapping tree.
@@ -1735,16 +1763,10 @@ bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
{
- bool r = false;
- struct dm_thin_device *td, *tmp;
+ bool r;
down_read(&pmd->root_lock);
- list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
- if (td->changed) {
- r = td->changed;
- break;
- }
- }
+ r = pmd->changed;
up_read(&pmd->root_lock);
return r;
@@ -1782,7 +1804,7 @@ int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
goto out;
r = __commit_transaction(pmd);
- if (r <= 0)
+ if (r < 0)
goto out;
/*
--
2.18.0
--
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