/*
- * dm-snapshot.c
+ * dm-exception-store.c
*
* Copyright (C) 2001-2002 Sistina Software (UK) Limited.
+ * Copyright (C) 2006 Red Hat GmbH
*
* This file is released under the GPL.
*/
atomic_t pending_count;
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);
}
ps->area = NULL;
}
+struct mdata_req {
+ struct 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, uint32_t chunk, int rw, int metadata)
{
- struct io_region where;
- unsigned long bits;
+ struct io_region where = {
+ .bdev = ps->snap->cow->bdev,
+ .sector = ps->snap->chunk_size * chunk,
+ .count = ps->snap->chunk_size,
+ };
+ struct dm_io_request io_req = {
+ .bi_rw = rw,
+ .mem.type = DM_IO_VMA,
+ .mem.ptr.vma = ps->area,
+ .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;
- where.bdev = ps->snap->cow->bdev;
- where.sector = ps->snap->chunk_size * chunk;
- where.count = ps->snap->chunk_size;
+ /*
+ * 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 dm_io_sync_vm(1, &where, rw, ps->area, &bits);
+ return req.result;
}
/*
/* convert a metadata area index to a chunk index */
chunk = 1 + ((ps->exceptions_per_area + 1) * area);
- r = chunk_io(ps, chunk, rw);
+ r = chunk_io(ps, chunk, rw, 0);
if (r)
return r;
chunk_size_supplied = 0;
}
- r = dm_io_get(sectors_to_pages(ps->snap->chunk_size));
- if (r)
- return r;
+ ps->io_client = dm_io_client_create(sectors_to_pages(ps->snap->
+ chunk_size));
+ if (IS_ERR(ps->io_client))
+ return PTR_ERR(ps->io_client);
r = alloc_area(ps);
if (r)
- goto bad1;
+ return r;
- r = chunk_io(ps, 0, READ);
+ r = chunk_io(ps, 0, READ, 1);
if (r)
- goto bad2;
+ goto bad;
dh = (struct disk_header *) ps->area;
if (le32_to_cpu(dh->magic) != SNAP_MAGIC) {
DMWARN("Invalid or corrupt snapshot");
r = -ENXIO;
- goto bad2;
+ goto bad;
}
*new_snapshot = 0;
(unsigned long long)ps->snap->chunk_size);
/* We had a bogus chunk_size. Fix stuff up. */
- dm_io_put(sectors_to_pages(ps->snap->chunk_size));
free_area(ps);
ps->snap->chunk_size = chunk_size;
ps->snap->chunk_mask = chunk_size - 1;
ps->snap->chunk_shift = ffs(chunk_size) - 1;
- r = dm_io_get(sectors_to_pages(chunk_size));
+ r = dm_io_client_resize(sectors_to_pages(ps->snap->chunk_size),
+ ps->io_client);
if (r)
return r;
r = alloc_area(ps);
- if (r)
- goto bad1;
-
- return 0;
+ return r;
-bad2:
+bad:
free_area(ps);
-bad1:
- dm_io_put(sectors_to_pages(ps->snap->chunk_size));
return r;
}
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);
}
/*
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);
- dm_io_put(sectors_to_pages(ps->snap->chunk_size));
+ destroy_workqueue(ps->metadata_wq);
+ dm_io_client_destroy(ps->io_client);
vfree(ps->callbacks);
free_area(ps);
kfree(ps);
/*
* 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;
}
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