From b87080efa2b049d968e5dde0f6cee58bdc826721 Mon Sep 17 00:00:00 2001
From: Jim Harris <james.r.harris@intel.com>
Date: Mon, 16 Dec 2019 09:10:16 -0700
Subject: [PATCH] bdev: add lba_range and overlapping checks

This will be used by upcoming patches for implementing
LBA range locks.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Ifa4ad8dcc0d09ccf20d35f010fcae19dcc17abc9

Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/478224
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Maciej Szwed <maciej.szwed@intel.com>
---
 lib/bdev/bdev.c                     | 27 ++++++++++++++++
 test/unit/lib/bdev/bdev.c/bdev_ut.c | 48 ++++++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/lib/bdev/bdev.c b/lib/bdev/bdev.c
index 251972d5f..6061757a3 100644
--- a/lib/bdev/bdev.c
+++ b/lib/bdev/bdev.c
@@ -124,6 +124,12 @@ static struct spdk_bdev_mgr g_bdev_mgr = {
 	.mutex = PTHREAD_MUTEX_INITIALIZER,
 };
 
+struct lba_range {
+	uint64_t			offset;
+	uint64_t			length;
+	struct spdk_bdev_channel	*owner_ch;
+	TAILQ_ENTRY(lba_range)		tailq;
+};
 
 static struct spdk_bdev_opts	g_bdev_opts = {
 	.bdev_io_pool_size = SPDK_BDEV_IO_POOL_SIZE,
@@ -1894,6 +1900,27 @@ _bdev_io_submit(void *ctx)
 	bdev_io->internal.in_submit_request = false;
 }
 
+bool
+bdev_lba_range_overlapped(struct lba_range *range1, struct lba_range *range2);
+
+bool
+bdev_lba_range_overlapped(struct lba_range *range1, struct lba_range *range2)
+{
+	if (range1->length == 0 || range2->length == 0) {
+		return false;
+	}
+
+	if (range1->offset + range1->length <= range2->offset) {
+		return false;
+	}
+
+	if (range2->offset + range2->length <= range1->offset) {
+		return false;
+	}
+
+	return true;
+}
+
 void
 bdev_io_submit(struct spdk_bdev_io *bdev_io)
 {
diff --git a/test/unit/lib/bdev/bdev.c/bdev_ut.c b/test/unit/lib/bdev/bdev.c/bdev_ut.c
index 625dc3c57..423a179cd 100644
--- a/test/unit/lib/bdev/bdev.c/bdev_ut.c
+++ b/test/unit/lib/bdev/bdev.c/bdev_ut.c
@@ -2541,6 +2541,51 @@ bdev_set_io_timeout(void)
 	poll_threads();
 }
 
+static void
+lba_range_overlap(void)
+{
+	struct lba_range r1, r2;
+
+	r1.offset = 100;
+	r1.length = 50;
+
+	r2.offset = 0;
+	r2.length = 1;
+	CU_ASSERT(!bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 0;
+	r2.length = 100;
+	CU_ASSERT(!bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 0;
+	r2.length = 110;
+	CU_ASSERT(bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 100;
+	r2.length = 10;
+	CU_ASSERT(bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 110;
+	r2.length = 20;
+	CU_ASSERT(bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 140;
+	r2.length = 150;
+	CU_ASSERT(bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 130;
+	r2.length = 200;
+	CU_ASSERT(bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 150;
+	r2.length = 100;
+	CU_ASSERT(!bdev_lba_range_overlapped(&r1, &r2));
+
+	r2.offset = 110;
+	r2.length = 0;
+	CU_ASSERT(!bdev_lba_range_overlapped(&r1, &r2));
+}
+
 int
 main(int argc, char **argv)
 {
@@ -2576,7 +2621,8 @@ main(int argc, char **argv)
 		CU_add_test(suite, "bdev_open_while_hotremove", bdev_open_while_hotremove) == NULL ||
 		CU_add_test(suite, "bdev_close_while_hotremove", bdev_close_while_hotremove) == NULL ||
 		CU_add_test(suite, "bdev_open_ext", bdev_open_ext) == NULL ||
-		CU_add_test(suite, "bdev_set_io_timeout", bdev_set_io_timeout) == NULL
+		CU_add_test(suite, "bdev_set_io_timeout", bdev_set_io_timeout) == NULL ||
+		CU_add_test(suite, "lba_range_overlap", lba_range_overlap) == NULL
 	) {
 		CU_cleanup_registry();
 		return CU_get_error();