dm snapshot: refactor zero_disk_area to use chunk_io

Refactor chunk_io to prepare for the fix in the following patch.

Pass an area pointer to chunk_io and simplify zero_disk_area to use
chunk_io.  No functional change.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 7 insertions, 19 deletions

diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 6e3fe4f14934..2a3d626a98d9 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -188,7 +188,8 @@ static void do_metadata(struct work_struct *work)
 /*
  * Read or write a chunk aligned and sized block of data from a device.
  */
-static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
+static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, int rw,
+                    int metadata)
 {
         struct dm_io_region where = {
                 .bdev = ps->store->cow->bdev,
@@ -198,7 +199,7 @@ static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
         struct dm_io_request io_req = {
                 .bi_rw = rw,
                 .mem.type = DM_IO_VMA,
-                .mem.ptr.vma = ps->area,
+                .mem.ptr.vma = area,
                 .client = ps->io_client,
                 .notify.fn = NULL,
         };
@@ -240,7 +241,7 @@ static int area_io(struct pstore *ps, int rw)
 
         chunk = area_location(ps, ps->current_area);
 
-        r = chunk_io(ps, chunk, rw, 0);
+        r = chunk_io(ps, ps->area, chunk, rw, 0);
         if (r)
                 return r;
 
@@ -254,20 +255,7 @@ static void zero_memory_area(struct pstore *ps)
 
 static int zero_disk_area(struct pstore *ps, chunk_t area)
 {
-        struct dm_io_region where = {
-                .bdev = ps->store->cow->bdev,
-                .sector = ps->store->chunk_size * area_location(ps, area),
-                .count = ps->store->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);
+        return chunk_io(ps, ps->zero_area, area_location(ps, area), WRITE, 0);
 }
 
 static int read_header(struct pstore *ps, int *new_snapshot)
@@ -297,7 +285,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         if (r)
                 return r;
 
-        r = chunk_io(ps, 0, READ, 1);
+        r = chunk_io(ps, ps->area, 0, READ, 1);
         if (r)
                 goto bad;
 
@@ -359,7 +347,7 @@ static int write_header(struct pstore *ps)
         dh->version = cpu_to_le32(ps->version);
         dh->chunk_size = cpu_to_le32(ps->store->chunk_size);
 
-        return chunk_io(ps, 0, WRITE, 1);
+        return chunk_io(ps, ps->area, 0, WRITE, 1);
 }
 
 /*