From: Joe Thornber <ejt@xxxxxxxxxx>
Retrieve the next run of contiguously mapped blocks. Useful for working
out where to break up IO.
Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-thin-metadata.c | 57 +++++++++++++++++++++++++++++++++++++++++++
drivers/md/dm-thin-metadata.h | 9 +++++++
2 files changed, 66 insertions(+)
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 79f6941..edcf4fb 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -1419,6 +1419,63 @@ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
return r;
}
+/* FIXME: write a more efficient one in btree */
+int dm_thin_find_mapped_range(struct dm_thin_device *td,
+ dm_block_t begin, dm_block_t end,
+ dm_block_t *thin_begin, dm_block_t *thin_end,
+ dm_block_t *pool_begin, bool *maybe_shared)
+{
+ int r;
+ dm_block_t pool_end;
+ struct dm_thin_lookup_result lookup;
+
+ if (end < begin)
+ return -ENODATA;
+
+ /*
+ * Find first mapped block.
+ */
+ while (begin < end) {
+ r = dm_thin_find_block(td, begin, true, &lookup);
+ if (r) {
+ if (r != -ENODATA)
+ return r;
+ } else
+ break;
+
+ begin++;
+ }
+
+ if (begin == end)
+ return -ENODATA;
+
+ *thin_begin = begin;
+ *pool_begin = lookup.block;
+ *maybe_shared = lookup.shared;
+
+ begin++;
+ pool_end = *pool_begin + 1;
+ while (begin != end) {
+ r = dm_thin_find_block(td, begin, true, &lookup);
+ if (r) {
+ if (r == -ENODATA)
+ break;
+ else
+ return r;
+ }
+
+ if ((lookup.block != pool_end) ||
+ (lookup.shared != *maybe_shared))
+ break;
+
+ pool_end++;
+ begin++;
+ }
+
+ *thin_end = begin;
+ return 0;
+}
+
static int __insert(struct dm_thin_device *td, dm_block_t block,
dm_block_t data_block)
{
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index fac01a9..f11f140 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -147,6 +147,15 @@ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
int can_issue_io, struct dm_thin_lookup_result *result);
/*
+ * Retrieve the next run of contiguously mapped blocks. Useful for working
+ * out where to break up IO. Returns 0 on success, < 0 on error.
+ */
+int dm_thin_find_mapped_range(struct dm_thin_device *td,
+ dm_block_t begin, dm_block_t end,
+ dm_block_t *thin_begin, dm_block_t *thin_end,
+ dm_block_t *pool_begin, bool *maybe_shared);
+
+/*
* Obtain an unused block.
*/
int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result);
--
2.3.2 (Apple Git-55)
--
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