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path: root/drivers/md/dm-exception-store.c
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Diffstat (limited to 'drivers/md/dm-exception-store.c')
-rw-r--r--drivers/md/dm-exception-store.c65
1 files changed, 42 insertions, 23 deletions
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index cc07bbebbb1..34a75939a0c 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -91,7 +91,6 @@ struct pstore {
struct dm_snapshot *snap; /* up pointer to my snapshot */
int version;
int valid;
- uint32_t chunk_size;
uint32_t exceptions_per_area;
/*
@@ -133,7 +132,7 @@ static int alloc_area(struct pstore *ps)
int r = -ENOMEM;
size_t len;
- len = ps->chunk_size << SECTOR_SHIFT;
+ len = ps->snap->chunk_size << SECTOR_SHIFT;
/*
* Allocate the chunk_size block of memory that will hold
@@ -160,8 +159,8 @@ static int chunk_io(struct pstore *ps, uint32_t chunk, int rw)
unsigned long bits;
where.bdev = ps->snap->cow->bdev;
- where.sector = ps->chunk_size * chunk;
- where.count = ps->chunk_size;
+ where.sector = ps->snap->chunk_size * chunk;
+ where.count = ps->snap->chunk_size;
return dm_io_sync_vm(1, &where, rw, ps->area, &bits);
}
@@ -188,7 +187,7 @@ static int area_io(struct pstore *ps, uint32_t area, int rw)
static int zero_area(struct pstore *ps, uint32_t area)
{
- memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
+ memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
return area_io(ps, area, WRITE);
}
@@ -196,6 +195,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
{
int r;
struct disk_header *dh;
+ chunk_t chunk_size;
r = chunk_io(ps, 0, READ);
if (r)
@@ -210,8 +210,29 @@ static int read_header(struct pstore *ps, int *new_snapshot)
*new_snapshot = 0;
ps->valid = le32_to_cpu(dh->valid);
ps->version = le32_to_cpu(dh->version);
- ps->chunk_size = le32_to_cpu(dh->chunk_size);
-
+ chunk_size = le32_to_cpu(dh->chunk_size);
+ if (ps->snap->chunk_size != chunk_size) {
+ DMWARN("chunk size %llu in device metadata overrides "
+ "table chunk size of %llu.",
+ (unsigned long long)chunk_size,
+ (unsigned long long)ps->snap->chunk_size);
+
+ /* We had a bogus chunk_size. Fix stuff up. */
+ dm_io_put(sectors_to_pages(ps->snap->chunk_size));
+ free_area(ps);
+
+ ps->snap->chunk_size = chunk_size;
+ ps->snap->chunk_mask = chunk_size - 1;
+ ps->snap->chunk_shift = ffs(chunk_size) - 1;
+
+ r = alloc_area(ps);
+ if (r)
+ return r;
+
+ r = dm_io_get(sectors_to_pages(chunk_size));
+ if (r)
+ return r;
+ }
} else {
DMWARN("Invalid/corrupt snapshot");
r = -ENXIO;
@@ -224,13 +245,13 @@ static int write_header(struct pstore *ps)
{
struct disk_header *dh;
- memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
+ memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
dh = (struct disk_header *) ps->area;
dh->magic = cpu_to_le32(SNAP_MAGIC);
dh->valid = cpu_to_le32(ps->valid);
dh->version = cpu_to_le32(ps->version);
- dh->chunk_size = cpu_to_le32(ps->chunk_size);
+ dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);
return chunk_io(ps, 0, WRITE);
}
@@ -365,7 +386,7 @@ static void persistent_destroy(struct exception_store *store)
{
struct pstore *ps = get_info(store);
- dm_io_put(sectors_to_pages(ps->chunk_size));
+ dm_io_put(sectors_to_pages(ps->snap->chunk_size));
vfree(ps->callbacks);
free_area(ps);
kfree(ps);
@@ -384,6 +405,16 @@ static int persistent_read_metadata(struct exception_store *store)
return r;
/*
+ * Now we know correct chunk_size, complete the initialisation.
+ */
+ ps->exceptions_per_area = (ps->snap->chunk_size << SECTOR_SHIFT) /
+ sizeof(struct disk_exception);
+ ps->callbacks = dm_vcalloc(ps->exceptions_per_area,
+ sizeof(*ps->callbacks));
+ if (!ps->callbacks)
+ return -ENOMEM;
+
+ /*
* Do we need to setup a new snapshot ?
*/
if (new_snapshot) {
@@ -533,9 +564,6 @@ int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
ps->snap = store->snap;
ps->valid = 1;
ps->version = SNAPSHOT_DISK_VERSION;
- ps->chunk_size = chunk_size;
- ps->exceptions_per_area = (chunk_size << SECTOR_SHIFT) /
- sizeof(struct disk_exception);
ps->next_free = 2; /* skipping the header and first area */
ps->current_committed = 0;
@@ -543,18 +571,9 @@ int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
if (r)
goto bad;
- /*
- * Allocate space for all the callbacks.
- */
ps->callback_count = 0;
atomic_set(&ps->pending_count, 0);
- ps->callbacks = dm_vcalloc(ps->exceptions_per_area,
- sizeof(*ps->callbacks));
-
- if (!ps->callbacks) {
- r = -ENOMEM;
- goto bad;
- }
+ ps->callbacks = NULL;
store->destroy = persistent_destroy;
store->read_metadata = persistent_read_metadata;