#include "dm.h"
#include "dm-snap.h"
-#include "dm-io.h"
-#include "kcopyd.h"
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
+#include <linux/dm-io.h>
+#include <linux/dm-kcopyd.h>
#define DM_MSG_PREFIX "snapshots"
#define DM_CHUNK_SIZE_DEFAULT_SECTORS 32 /* 16KB */
* Used to keep track of which metadata area the data in
* 'chunk' refers to.
*/
- uint32_t current_area;
+ chunk_t current_area;
/*
* The next free chunk for an exception.
*/
- uint32_t next_free;
+ chunk_t next_free;
/*
* The index of next free exception in the current
uint32_t callback_count;
struct commit_callback *callbacks;
struct dm_io_client *io_client;
+
+ struct workqueue_struct *metadata_wq;
};
-static inline unsigned int sectors_to_pages(unsigned int sectors)
+static unsigned sectors_to_pages(unsigned sectors)
{
- return sectors / (PAGE_SIZE >> 9);
+ return DIV_ROUND_UP(sectors, PAGE_SIZE >> 9);
}
static int alloc_area(struct pstore *ps)
ps->area = NULL;
}
+struct mdata_req {
+ struct dm_io_region *where;
+ struct dm_io_request *io_req;
+ struct work_struct work;
+ int result;
+};
+
+static void do_metadata(struct work_struct *work)
+{
+ struct mdata_req *req = container_of(work, struct mdata_req, work);
+
+ req->result = dm_io(req->io_req, 1, req->where, NULL);
+}
+
/*
* Read or write a chunk aligned and sized block of data from a device.
*/
-static int chunk_io(struct pstore *ps, uint32_t chunk, int rw)
+static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
{
- struct io_region where = {
+ struct dm_io_region where = {
.bdev = ps->snap->cow->bdev,
.sector = ps->snap->chunk_size * chunk,
.count = ps->snap->chunk_size,
.client = ps->io_client,
.notify.fn = NULL,
};
+ struct mdata_req req;
+
+ if (!metadata)
+ return dm_io(&io_req, 1, &where, NULL);
+
+ req.where = &where;
+ req.io_req = &io_req;
+
+ /*
+ * Issue the synchronous I/O from a different thread
+ * to avoid generic_make_request recursion.
+ */
+ INIT_WORK(&req.work, do_metadata);
+ queue_work(ps->metadata_wq, &req.work);
+ flush_workqueue(ps->metadata_wq);
+
+ return req.result;
+}
- return dm_io(&io_req, 1, &where, NULL);
+/*
+ * Convert a metadata area index to a chunk index.
+ */
+static chunk_t area_location(struct pstore *ps, chunk_t area)
+{
+ return 1 + ((ps->exceptions_per_area + 1) * area);
}
/*
* Read or write a metadata area. Remembering to skip the first
* chunk which holds the header.
*/
-static int area_io(struct pstore *ps, uint32_t area, int rw)
+static int area_io(struct pstore *ps, chunk_t area, int rw)
{
int r;
- uint32_t chunk;
+ chunk_t chunk;
- /* convert a metadata area index to a chunk index */
- chunk = 1 + ((ps->exceptions_per_area + 1) * area);
+ chunk = area_location(ps, area);
- r = chunk_io(ps, chunk, rw);
+ r = chunk_io(ps, chunk, rw, 0);
if (r)
return r;
return 0;
}
-static int zero_area(struct pstore *ps, uint32_t area)
+static int zero_area(struct pstore *ps, chunk_t area)
{
memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
return area_io(ps, area, WRITE);
if (r)
return r;
- r = chunk_io(ps, 0, READ);
+ r = chunk_io(ps, 0, READ, 1);
if (r)
goto bad;
dh->version = cpu_to_le32(ps->version);
dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);
- return chunk_io(ps, 0, WRITE);
+ return chunk_io(ps, 0, WRITE, 1);
}
/*
static int read_exceptions(struct pstore *ps)
{
- uint32_t area;
+ chunk_t area;
int r, full = 1;
/*
return 0;
}
-static inline struct pstore *get_info(struct exception_store *store)
+static struct pstore *get_info(struct exception_store *store)
{
return (struct pstore *) store->context;
}
{
struct pstore *ps = get_info(store);
+ destroy_workqueue(ps->metadata_wq);
dm_io_client_destroy(ps->io_client);
vfree(ps->callbacks);
free_area(ps);
static int persistent_read_metadata(struct exception_store *store)
{
- int r, new_snapshot;
+ int r, uninitialized_var(new_snapshot);
struct pstore *ps = get_info(store);
/*
/*
* Sanity checks.
*/
- if (!ps->valid) {
- DMWARN("snapshot is marked invalid");
- return -EINVAL;
- }
-
if (ps->version != SNAPSHOT_DISK_VERSION) {
DMWARN("unable to handle snapshot disk version %d",
ps->version);
return -EINVAL;
}
+ /*
+ * Metadata are valid, but snapshot is invalidated
+ */
+ if (!ps->valid)
+ return 1;
+
/*
* Read the metadata.
*/
}
static int persistent_prepare(struct exception_store *store,
- struct exception *e)
+ struct dm_snap_exception *e)
{
struct pstore *ps = get_info(store);
uint32_t stride;
+ chunk_t next_free;
sector_t size = get_dev_size(store->snap->cow->bdev);
/* Is there enough room ? */
* into account the location of the metadata chunks.
*/
stride = (ps->exceptions_per_area + 1);
- if ((++ps->next_free % stride) == 1)
+ next_free = ++ps->next_free;
+ if (sector_div(next_free, stride) == 1)
ps->next_free++;
atomic_inc(&ps->pending_count);
}
static void persistent_commit(struct exception_store *store,
- struct exception *e,
+ struct dm_snap_exception *e,
void (*callback) (void *, int success),
void *callback_context)
{
atomic_set(&ps->pending_count, 0);
ps->callbacks = NULL;
+ ps->metadata_wq = create_singlethread_workqueue("ksnaphd");
+ if (!ps->metadata_wq) {
+ kfree(ps);
+ DMERR("couldn't start header metadata update thread");
+ return -ENOMEM;
+ }
+
store->destroy = persistent_destroy;
store->read_metadata = persistent_read_metadata;
store->prepare_exception = persistent_prepare;
return 0;
}
-static int transient_prepare(struct exception_store *store, struct exception *e)
+static int transient_prepare(struct exception_store *store,
+ struct dm_snap_exception *e)
{
struct transient_c *tc = (struct transient_c *) store->context;
sector_t size = get_dev_size(store->snap->cow->bdev);
}
static void transient_commit(struct exception_store *store,
- struct exception *e,
- void (*callback) (void *, int success),
- void *callback_context)
+ struct dm_snap_exception *e,
+ void (*callback) (void *, int success),
+ void *callback_context)
{
/* Just succeed */
callback(callback_context, 1);
projects / linux-2.6-omap-h63xx.git / blobdiff