[PATCH 15/26] range: Add range_overlaps()

Ira Weiny
2024-03-24T23:18:22Z

Code to support CXL Dynamic Capacity devices will have extent ranges
which need to be compared for intersection not a subset as is being
checked in range_contains().

range_overlaps() is defined in btrfs with a different meaning from what
is required in the standard range code. Dan Williams pointed this out
in [1]. Adjust the btrfs call according to his suggestion there.

Then add a generic range_overlaps().

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

[1] https://lore.kernel.org/all/65949f79ef908_8dc68294f2@dwillia2-xfh.jf.intel.com.notmuch/
---
fs/btrfs/ordered-data.c | 10 +++++-----
include/linux/range.h | 7 +++++++
2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 59850dc17b22..032d30a49edc 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -111,8 +111,8 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
return NULL;
}

-static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
- u64 len)
+static int btrfs_range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
+ u64 len)
{
if (file_offset + len <= entry->file_offset ||
entry->file_offset + entry->num_bytes <= file_offset)
@@ -914,7 +914,7 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_range(

while (1) {
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
- if (range_overlaps(entry, file_offset, len))
+ if (btrfs_range_overlaps(entry, file_offset, len))
break;

if (entry->file_offset >= file_offset + len) {
@@ -1043,12 +1043,12 @@ struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
}
if (prev) {
entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
- if (range_overlaps(entry, file_offset, len))
+ if (btrfs_range_overlaps(entry, file_offset, len))
goto out;
}
if (next) {
entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
- if (range_overlaps(entry, file_offset, len))
+ if (btrfs_range_overlaps(entry, file_offset, len))
goto out;
}
/* No ordered extent in the range */
diff --git a/include/linux/range.h b/include/linux/range.h
index 6ad0b73cb7ad..9a46f3212965 100644
--- a/include/linux/range.h
+++ b/include/linux/range.h
@@ -13,11 +13,18 @@ static inline u64 range_len(const struct range *range)
return range->end - range->start + 1;
}

+/* True if r1 completely contains r2 */
static inline bool range_contains(struct range *r1, struct range *r2)
{
return r1->start <= r2->start && r1->end >= r2->end;
}

+/* True if any part of r1 overlaps r2 */
+static inline bool range_overlaps(struct range *r1, struct range *r2)
+{
+ return r1->start <= r2->end && r1->end >= r2->start;
+}
+
int add_range(struct range *range, int az, int nr_range,
u64 start, u64 end);

--
2.44.0