On Wed, 29 Oct 2008 23:48:52 +0000
Alasdair G Kergon <agk@xxxxxxxxxx> wrote:
> On Mon, Oct 27, 2008 at 09:07:48PM +0900, FUJITA Tomonori wrote:
> > 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.
>
> > +static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata,
> > + void *data)
>
> data is part of ps so should not need passing in as it's already accessible!
The later patches uses chunk_io() to I/O for any data buffer (that is,
buffers are not in pstore).
> It's looking like struct pstore is acquiring fields that apply to only one
> type of snapshot: IOW More-invasive refactoring of that struct is needed.
> - Which fields apply to both? Which apply only to one type of snapshot?
The 7/9 patch adds the following fields to struct pstore:
struct disk_exception {
@@ -131,6 +146,27 @@ struct pstore {
struct dm_io_client *io_client;
struct workqueue_struct *metadata_wq;
+
+ /*
+ * for shared exception
+ */
+ u64 root_tree_chunk;
+ u64 snapmask;
+ u32 tree_level;
+
+ u32 nr_snapshots;
+
+ unsigned long nr_chunks;
+ unsigned long nr_bitmap_chunks;
+ unsigned long *bitmap;
+ unsigned long cur_bitmap_chunk;
+ unsigned long cur_bitmap_index;
+
+ struct list_head chunk_buffer_list;
+ struct list_head chunk_buffer_dirty_list;
+
+ int header_dirty;
+ int nr_chunk_buffers;
The new snapshot code uses the following existing fields in struct
pstore:
void *zero_area;
chunk_t current_area;
chunk_t next_free;
uint32_t current_committed;
Do you want to split struct pstore?
Thanks,
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