* This file is released under the GPL.
*/
-#include "dm.h"
#include "dm-snap.h"
#include <linux/mm.h>
*/
void *area;
+ /*
+ * An area of zeros used to clear the next area.
+ */
+ void *zero_area;
+
/*
* 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
if (!ps->area)
return r;
+ ps->zero_area = vmalloc(len);
+ if (!ps->zero_area) {
+ vfree(ps->area);
+ return r;
+ }
+ memset(ps->zero_area, 0, len);
+
return 0;
}
{
vfree(ps->area);
ps->area = NULL;
+ vfree(ps->zero_area);
+ ps->zero_area = NULL;
}
struct mdata_req {
/*
* 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, int metadata)
+static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
{
struct dm_io_region where = {
.bdev = ps->snap->cow->bdev,
return req.result;
}
+/*
+ * 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, 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, ps->current_area);
r = chunk_io(ps, chunk, rw, 0);
if (r)
return r;
- ps->current_area = area;
return 0;
}
-static int zero_area(struct pstore *ps, uint32_t area)
+static void zero_memory_area(struct pstore *ps)
{
memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
- return area_io(ps, area, WRITE);
+}
+
+static int zero_disk_area(struct pstore *ps, chunk_t area)
+{
+ struct dm_io_region where = {
+ .bdev = ps->snap->cow->bdev,
+ .sector = ps->snap->chunk_size * area_location(ps, area),
+ .count = ps->snap->chunk_size,
+ };
+ struct dm_io_request io_req = {
+ .bi_rw = WRITE,
+ .mem.type = DM_IO_VMA,
+ .mem.ptr.vma = ps->zero_area,
+ .client = ps->io_client,
+ .notify.fn = NULL,
+ };
+
+ return dm_io(&io_req, 1, &where, NULL);
}
static int read_header(struct pstore *ps, int *new_snapshot)
static int read_exceptions(struct pstore *ps)
{
- uint32_t area;
int r, full = 1;
/*
* Keeping reading chunks and inserting exceptions until
* we find a partially full area.
*/
- for (area = 0; full; area++) {
- r = area_io(ps, area, READ);
+ for (ps->current_area = 0; full; ps->current_area++) {
+ r = area_io(ps, READ);
if (r)
return r;
return r;
}
+ ps->current_area--;
+
return 0;
}
return r;
}
- r = zero_area(ps, 0);
+ ps->current_area = 0;
+ zero_memory_area(ps);
+ r = zero_disk_area(ps, 0);
if (r) {
- DMWARN("zero_area(0) failed");
+ DMWARN("zero_disk_area(0) failed");
return r;
}
-
} else {
/*
* Sanity checks.
{
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);
void (*callback) (void *, int success),
void *callback_context)
{
- int r;
unsigned int i;
struct pstore *ps = get_info(store);
struct disk_exception de;
cb->context = callback_context;
/*
- * If there are no more exceptions in flight, or we have
- * filled this metadata area we commit the exceptions to
- * disk.
+ * If there are exceptions in flight and we have not yet
+ * filled this metadata area there's nothing more to do.
*/
- if (atomic_dec_and_test(&ps->pending_count) ||
- (ps->current_committed == ps->exceptions_per_area)) {
- r = area_io(ps, ps->current_area, WRITE);
- if (r)
- ps->valid = 0;
+ if (!atomic_dec_and_test(&ps->pending_count) &&
+ (ps->current_committed != ps->exceptions_per_area))
+ return;
- /*
- * Have we completely filled the current area ?
- */
- if (ps->current_committed == ps->exceptions_per_area) {
- ps->current_committed = 0;
- r = zero_area(ps, ps->current_area + 1);
- if (r)
- ps->valid = 0;
- }
+ /*
+ * If we completely filled the current area, then wipe the next one.
+ */
+ if ((ps->current_committed == ps->exceptions_per_area) &&
+ zero_disk_area(ps, ps->current_area + 1))
+ ps->valid = 0;
- for (i = 0; i < ps->callback_count; i++) {
- cb = ps->callbacks + i;
- cb->callback(cb->context, r == 0 ? 1 : 0);
- }
+ /*
+ * Commit exceptions to disk.
+ */
+ if (ps->valid && area_io(ps, WRITE))
+ ps->valid = 0;
+
+ /*
+ * Advance to the next area if this one is full.
+ */
+ if (ps->current_committed == ps->exceptions_per_area) {
+ ps->current_committed = 0;
+ ps->current_area++;
+ zero_memory_area(ps);
+ }
- ps->callback_count = 0;
+ for (i = 0; i < ps->callback_count; i++) {
+ cb = ps->callbacks + i;
+ cb->callback(cb->context, ps->valid);
}
+
+ ps->callback_count = 0;
}
static void persistent_drop(struct exception_store *store)
projects / linux-2.6-omap-h63xx.git / blobdiff