[dm-devel] [PATCH 01/10] dm snapshot: make chunk_io handle any buffer

[FUJITA Tomonori]

chunk_io() can perform I/Os only with ps->area. This patch adds a new
argument (a pointer to a buffer) to chunk_io() so that it can performs
I/Os with the buffer.

Signed-off-by: FUJITA Tomonori <fujita.tomonori at lab.ntt.co.jp>
---
 drivers/md/dm-exception-store.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 41f4080..fe5f8b4 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -175,7 +175,8 @@ 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, uint32_t chunk, int rw, int metadata)
+static int chunk_io(struct pstore *ps, uint32_t chunk, int rw, int metadata,
+		    void *data)
 {
 	struct dm_io_region where = {
 		.bdev = ps->snap->cow->bdev,
@@ -185,7 +186,7 @@ static int chunk_io(struct pstore *ps, uint32_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 = data,
 		.client = ps->io_client,
 		.notify.fn = NULL,
 	};
@@ -220,7 +221,7 @@ static int area_io(struct pstore *ps, uint32_t area, int rw)
 	/* convert a metadata area index to a chunk index */
 	chunk = 1 + ((ps->exceptions_per_area + 1) * area);
 
-	r = chunk_io(ps, chunk, rw, 0);
+	r = chunk_io(ps, chunk, rw, 0, ps->area);
 	if (r)
 		return r;
 
@@ -261,7 +262,7 @@ 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, 0, READ, 1, ps->area);
 	if (r)
 		goto bad;
 
@@ -323,7 +324,7 @@ static int write_header(struct pstore *ps)
 	dh->version = cpu_to_le32(ps->version);
 	dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);
 
-	return chunk_io(ps, 0, WRITE, 1);
+	return chunk_io(ps, 0, WRITE, 1, ps->area);
 }
 
 /*
-- 
1.5.5.GIT