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FAILED: patch "[PATCH] dm table: fix iterate_devices based device capability checks" failed to apply to 4.14-stable tree

PATCH In review [email protected] 2 participants 7 messages Mar 1, 2021 – Mar 7, 2021

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[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e Mon Sep 17 00:00:00 2001
From: Jeffle Xu <[email protected]>
Date: Tue, 2 Feb 2021 11:35:28 +0800
Subject: [PATCH] dm table: fix iterate_devices based device capability checks

According to the definition of dm_iterate_devices_fn:
* This function must iterate through each section of device used by the
* target until it encounters a non-zero return code, which it then returns.
* Returns zero if no callout returned non-zero.

For some target type (e.g. dm-stripe), one call of iterate_devices() may iterate multiple underlying devices internally, in which case a non-zero return code returned by iterate_devices_callout_fn will stop the iteration in advance. No iterate_devices_callout_fn should return non-zero unless device iteration should stop.

Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and elevate it for reuse to stop iterating (and return non-zero) on the first device that causes iterate_devices_callout_fn to return non-zero. Use dm_table_any_dev_attr() to properly iterate through devices.

Rename device_is_nonrot() to device_is_rotational() and invert logic accordingly to fix improper disposition.

Fixes c3c4555edd10 ("dm table: clear add_random unless all devices have it set")
Fixes 4693c9668fdc ("dm table: propagate non rotational flag")
drivers/md/dm-table.c +51 -46
index 4acf2342f7ad..3e211e64f348 100644
@@ -1295,6 +1295,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 	return &t->targets[(KEYS_PER_NODE * n) + k];
 }
 
+/*
+ * type->iterate_devices() should be called when the sanity check needs to
+ * iterate and check all underlying data devices. iterate_devices() will
+ * iterate all underlying data devices until it encounters a non-zero return
+ * code, returned by whether the input iterate_devices_callout_fn, or
+ * iterate_devices() itself internally.
+ *
+ * For some target type (e.g. dm-stripe), one call of iterate_devices() may
+ * iterate multiple underlying devices internally, in which case a non-zero
+ * return code returned by iterate_devices_callout_fn will stop the iteration
+ * in advance.
+ *
+ * Cases requiring _any_ underlying device supporting some kind of attribute,
+ * should use the iteration structure like dm_table_any_dev_attr(), or call
+ * it directly. @func should handle semantics of positive examples, e.g.
+ * capable of something.
+ *
+ * Cases requiring _all_ underlying devices supporting some kind of attribute,
+ * should use the iteration structure like dm_table_supports_nowait() or
+ * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
+ * uses an @anti_func that handle semantics of counter examples, e.g. not
+ * capable of something. So: return !dm_table_any_dev_attr(t, anti_func);
+ */
+static bool dm_table_any_dev_attr(struct dm_table *t,
+				  iterate_devices_callout_fn func)
+{
+	struct dm_target *ti;
+	unsigned int i;
+
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, func, NULL))
+			return true;
+        }
+
+	return false;
+}
+
 static int count_device(struct dm_target *ti, struct dm_dev *dev,
 			sector_t start, sector_t len, void *data)
 {
@@ -1595,12 +1635,12 @@ static int dm_table_supports_dax_write_cache(struct dm_table *t)
 	return false;
 }
 
-static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
-			    sector_t start, sector_t len, void *data)
+static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
+				sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 
-	return q && blk_queue_nonrot(q);
+	return q && !blk_queue_nonrot(q);
 }
 
 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
@@ -1611,23 +1651,6 @@ static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
 	return q && !blk_queue_add_random(q);
 }
 
-static bool dm_table_all_devices_attribute(struct dm_table *t,
-					   iterate_devices_callout_fn func)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, func, NULL))
-			return false;
-	}
-
-	return true;
-}
-
 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
 					 sector_t start, sector_t len, void *data)
 {
@@ -1779,27 +1802,6 @@ static int device_requires_stable_pages(struct dm_target *ti,
 	return q && blk_queue_stable_writes(q);
 }
 
-/*
- * If any underlying device requires stable pages, a table must require
- * them as well.  Only targets that support iterate_devices are considered:
- * don't want error, zero, etc to require stable pages.
- */
-static bool dm_table_requires_stable_pages(struct dm_table *t)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (ti->type->iterate_devices &&
-		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
-			return true;
-	}
-
-	return false;
-}
-
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 			       struct queue_limits *limits)
 {
@@ -1849,10 +1851,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 		dax_write_cache(t->md->dax_dev, true);
 
 	/* Ensure that all underlying devices are non-rotational. */
-	if (dm_table_all_devices_attribute(t, device_is_nonrot))
-		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
-	else
+	if (dm_table_any_dev_attr(t, device_is_rotational))
 		blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
+	else
+		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
 
 	if (!dm_table_supports_write_same(t))
 		q->limits.max_write_same_sectors = 0;
@@ -1864,8 +1866,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	/*
 	 * Some devices don't use blk_integrity but still want stable pages
 	 * because they do their own checksumming.
+	 * If any underlying device requires stable pages, a table must require
+	 * them as well.  Only targets that support iterate_devices are considered:
+	 * don't want error, zero, etc to require stable pages.
 	 */
-	if (dm_table_requires_stable_pages(t))
+	if (dm_table_any_dev_attr(t, device_requires_stable_pages))
 		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
 	else
 		blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
@@ -1876,7 +1881,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
 	 * have it set.
 	 */
-	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
+	if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random))
 		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
 
 	/*
#1 lore raw

cover dm: device capability check fixes

- patch 1/3/4 is from upstream
- patch 2 is to fix the code specific to 4.4 (has been removed in upstream)

Jeffle Xu (4):
dm table: fix iterate_devices based device capability checks dm table: fix no_sg_merge iterate_devices based device capability
checks
dm table: fix DAX iterate_devices based device capability checks dm table: fix zoned iterate_devices based device capability checks

 drivers/md/dm-table.c | 168 ++++++++++++++++++------------------------
 1 file changed, 70 insertions(+), 98 deletions(-)
Signature · 1 line
2.27.0
#4 lore raw

PATCH 2/4 dm table: fix no_sg_merge iterate_devices based device capability checks

Similar to commit a4c8dd9c2d09 ("dm table: fix iterate_devices based device capability checks"), fix NO_SG_MERGE capability check and invert logic of the corresponding iterate_devices_callout_fn so that all devices' NO_SG_MERGE capabilities are properly checked.

Fixes 200612ec33e5 ("dm table: propagate QUEUE_FLAG_NO_SG_MERGE")
---
 drivers/md/dm-table.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
drivers/md/dm-table.c +6 -6
index 6fe720e2c6ba..a40c51459ef5 100644
@@ -1723,12 +1723,12 @@ static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
 	return q && !blk_queue_add_random(q);
 }
 
-static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
-				   sector_t start, sector_t len, void *data)
+static int queue_no_sg_merge(struct dm_target *ti, struct dm_dev *dev,
+			     sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 
-	return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
+	return q && test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
 }
 
 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
@@ -1868,10 +1868,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	if (!dm_table_supports_write_zeroes(t))
 		q->limits.max_write_zeroes_sectors = 0;
 
-	if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
-		queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
-	else
+	if (dm_table_any_dev_attr(t, queue_no_sg_merge))
 		queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
+	else
+		queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
 
 	dm_table_verify_integrity(t);
 
Signature · 1 line
2.27.0
#5 lore raw

PATCH 3/4 dm table: fix DAX iterate_devices based device capability checks

In reply to Jeffle Xu

commit 57ba3e506c30a84b1ba1dd77ddd9f2be9d472e98 upstream.

Fix dm_table_supports_dax() and invert logic of both iterate_devices_callout_fn so that all devices' DAX capabilities are properly checked.

Fixes 545ed20e6df6 ("dm: add infrastructure for DAX support")
[jeffle: no dax synchronous]
---
 drivers/md/dm-table.c | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)
drivers/md/dm-table.c +4 -21
index a40c51459ef5..96ac87f9cb85 100644
@@ -889,10 +889,10 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 }
 EXPORT_SYMBOL_GPL(dm_table_set_type);
 
-static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 			       sector_t start, sector_t len, void *data)
 {
-	return bdev_dax_supported(dev->bdev, PAGE_SIZE);
+	return !bdev_dax_supported(dev->bdev, PAGE_SIZE);
 }
 
 static bool dm_table_supports_dax(struct dm_table *t)
@@ -908,7 +908,7 @@ static bool dm_table_supports_dax(struct dm_table *t)
 			return false;
 
 		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, device_supports_dax, NULL))
+		    ti->type->iterate_devices(ti, device_not_dax_capable, NULL))
 			return false;
 	}
 
@@ -1690,23 +1690,6 @@ static int device_dax_write_cache_enabled(struct dm_target *ti,
 	return false;
 }
 
-static int dm_table_supports_dax_write_cache(struct dm_table *t)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (ti->type->iterate_devices &&
-		    ti->type->iterate_devices(ti,
-				device_dax_write_cache_enabled, NULL))
-			return true;
-	}
-
-	return false;
-}
-
 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
 				sector_t start, sector_t len, void *data)
 {
@@ -1854,7 +1837,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	else
 		queue_flag_clear_unlocked(QUEUE_FLAG_DAX, q);
 
-	if (dm_table_supports_dax_write_cache(t))
+	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled))
 		dax_write_cache(t->md->dax_dev, true);
 
 	/* Ensure that all underlying devices are non-rotational. */
Signature · 1 line
2.27.0
#6 lore raw

PATCH 4/4 dm table: fix zoned iterate_devices based device capability checks

In reply to Jeffle Xu

commit 24f6b6036c9eec21191646930ad42808e6180510 upstream.

Fix dm_table_supports_zoned_model() and invert logic of both iterate_devices_callout_fn so that all devices' zoned capabilities are properly checked.

Add one more parameter to dm_table_any_dev_attr(), which is actually used as the @data parameter of iterate_devices_callout_fn, so that dm_table_matches_zone_sectors() can be replaced by dm_table_any_dev_attr().

Fixes dd88d313bef02 ("dm table: add zoned block devices validation")
[jeffle: also convert no_sg_merge check]
---
 drivers/md/dm-table.c | 50 +++++++++++++++----------------------------
 1 file changed, 17 insertions(+), 33 deletions(-)
drivers/md/dm-table.c +17 -33
index 96ac87f9cb85..3b2a880eed68 100644
@@ -1372,10 +1372,10 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
  * should use the iteration structure like dm_table_supports_nowait() or
  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
  * uses an @anti_func that handle semantics of counter examples, e.g. not
- * capable of something. So: return !dm_table_any_dev_attr(t, anti_func);
+ * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
  */
 static bool dm_table_any_dev_attr(struct dm_table *t,
-				  iterate_devices_callout_fn func)
+				  iterate_devices_callout_fn func, void *data)
 {
 	struct dm_target *ti;
 	unsigned int i;
@@ -1384,7 +1384,7 @@ static bool dm_table_any_dev_attr(struct dm_table *t,
 		ti = dm_table_get_target(t, i);
 
 		if (ti->type->iterate_devices &&
-		    ti->type->iterate_devices(ti, func, NULL))
+		    ti->type->iterate_devices(ti, func, data))
 			return true;
         }
 
@@ -1427,13 +1427,13 @@ bool dm_table_has_no_data_devices(struct dm_table *table)
 	return true;
 }
 
-static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
-				 sector_t start, sector_t len, void *data)
+static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
+				  sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 	enum blk_zoned_model *zoned_model = data;
 
-	return q && blk_queue_zoned_model(q) == *zoned_model;
+	return !q || blk_queue_zoned_model(q) != *zoned_model;
 }
 
 static bool dm_table_supports_zoned_model(struct dm_table *t,
@@ -1450,37 +1450,20 @@ static bool dm_table_supports_zoned_model(struct dm_table *t,
 			return false;
 
 		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
+		    ti->type->iterate_devices(ti, device_not_zoned_model, &zoned_model))
 			return false;
 	}
 
 	return true;
 }
 
-static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
-				       sector_t start, sector_t len, void *data)
+static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
+					   sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 	unsigned int *zone_sectors = data;
 
-	return q && blk_queue_zone_sectors(q) == *zone_sectors;
-}
-
-static bool dm_table_matches_zone_sectors(struct dm_table *t,
-					  unsigned int zone_sectors)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
-			return false;
-	}
-
-	return true;
+	return !q || blk_queue_zone_sectors(q) != *zone_sectors;
 }
 
 static int validate_hardware_zoned_model(struct dm_table *table,
@@ -1500,7 +1483,7 @@ static int validate_hardware_zoned_model(struct dm_table *table,
 	if (!zone_sectors || !is_power_of_2(zone_sectors))
 		return -EINVAL;
 
-	if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
+	if (dm_table_any_dev_attr(table, device_not_matches_zone_sectors, &zone_sectors)) {
 		DMERR("%s: zone sectors is not consistent across all devices",
 		      dm_device_name(table->md));
 		return -EINVAL;
@@ -1837,11 +1820,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	else
 		queue_flag_clear_unlocked(QUEUE_FLAG_DAX, q);
 
-	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled))
+	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
 		dax_write_cache(t->md->dax_dev, true);
 
 	/* Ensure that all underlying devices are non-rotational. */
-	if (dm_table_any_dev_attr(t, device_is_rotational))
+	if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
 		queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
 	else
 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
@@ -1851,7 +1834,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	if (!dm_table_supports_write_zeroes(t))
 		q->limits.max_write_zeroes_sectors = 0;
 
-	if (dm_table_any_dev_attr(t, queue_no_sg_merge))
+	if (dm_table_any_dev_attr(t, queue_no_sg_merge, NULL))
 		queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
 	else
 		queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
@@ -1865,7 +1848,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	 * them as well.  Only targets that support iterate_devices are considered:
 	 * don't want error, zero, etc to require stable pages.
 	 */
-	if (dm_table_any_dev_attr(t, device_requires_stable_pages))
+	if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
 		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
 	else
 		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
@@ -1876,7 +1859,8 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
 	 * have it set.
 	 */
-	if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random))
+	if (blk_queue_add_random(q) &&
+	    dm_table_any_dev_attr(t, device_is_not_random, NULL))
 		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
 
 	/*
Signature · 1 line
2.27.0
#2 lore raw

PATCH 1/4 dm table: fix iterate_devices based device capability checks

In reply to Jeffle Xu

commit a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e upstream.

According to the definition of dm_iterate_devices_fn:
* This function must iterate through each section of device used by the
* target until it encounters a non-zero return code, which it then returns.
* Returns zero if no callout returned non-zero.

For some target type (e.g. dm-stripe), one call of iterate_devices() may iterate multiple underlying devices internally, in which case a non-zero return code returned by iterate_devices_callout_fn will stop the iteration in advance. No iterate_devices_callout_fn should return non-zero unless device iteration should stop.

Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and elevate it for reuse to stop iterating (and return non-zero) on the first device that causes iterate_devices_callout_fn to return non-zero. Use dm_table_any_dev_attr() to properly iterate through devices.

Rename device_is_nonrot() to device_is_rotational() and invert logic accordingly to fix improper disposition.

Fixes c3c4555edd10 ("dm table: clear add_random unless all devices have it set")
Fixes 4693c9668fdc ("dm table: propagate non rotational flag")
---
 drivers/md/dm-table.c | 97 +++++++++++++++++++++++--------------------
 1 file changed, 51 insertions(+), 46 deletions(-)
drivers/md/dm-table.c +51 -46
index c855ab2feb18..6fe720e2c6ba 100644
@@ -1351,6 +1351,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 	return &t->targets[(KEYS_PER_NODE * n) + k];
 }
 
+/*
+ * type->iterate_devices() should be called when the sanity check needs to
+ * iterate and check all underlying data devices. iterate_devices() will
+ * iterate all underlying data devices until it encounters a non-zero return
+ * code, returned by whether the input iterate_devices_callout_fn, or
+ * iterate_devices() itself internally.
+ *
+ * For some target type (e.g. dm-stripe), one call of iterate_devices() may
+ * iterate multiple underlying devices internally, in which case a non-zero
+ * return code returned by iterate_devices_callout_fn will stop the iteration
+ * in advance.
+ *
+ * Cases requiring _any_ underlying device supporting some kind of attribute,
+ * should use the iteration structure like dm_table_any_dev_attr(), or call
+ * it directly. @func should handle semantics of positive examples, e.g.
+ * capable of something.
+ *
+ * Cases requiring _all_ underlying devices supporting some kind of attribute,
+ * should use the iteration structure like dm_table_supports_nowait() or
+ * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
+ * uses an @anti_func that handle semantics of counter examples, e.g. not
+ * capable of something. So: return !dm_table_any_dev_attr(t, anti_func);
+ */
+static bool dm_table_any_dev_attr(struct dm_table *t,
+				  iterate_devices_callout_fn func)
+{
+	struct dm_target *ti;
+	unsigned int i;
+
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, func, NULL))
+			return true;
+        }
+
+	return false;
+}
+
 static int count_device(struct dm_target *ti, struct dm_dev *dev,
 			sector_t start, sector_t len, void *data)
 {
@@ -1667,12 +1707,12 @@ static int dm_table_supports_dax_write_cache(struct dm_table *t)
 	return false;
 }
 
-static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
-			    sector_t start, sector_t len, void *data)
+static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
+				sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 
-	return q && blk_queue_nonrot(q);
+	return q && !blk_queue_nonrot(q);
 }
 
 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
@@ -1691,23 +1731,6 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
 	return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
 }
 
-static bool dm_table_all_devices_attribute(struct dm_table *t,
-					   iterate_devices_callout_fn func)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, func, NULL))
-			return false;
-	}
-
-	return true;
-}
-
 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
 					 sector_t start, sector_t len, void *data)
 {
@@ -1804,27 +1827,6 @@ static int device_requires_stable_pages(struct dm_target *ti,
 	return q && bdi_cap_stable_pages_required(q->backing_dev_info);
 }
 
-/*
- * If any underlying device requires stable pages, a table must require
- * them as well.  Only targets that support iterate_devices are considered:
- * don't want error, zero, etc to require stable pages.
- */
-static bool dm_table_requires_stable_pages(struct dm_table *t)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (ti->type->iterate_devices &&
-		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
-			return true;
-	}
-
-	return false;
-}
-
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 			       struct queue_limits *limits)
 {
@@ -1856,10 +1858,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 		dax_write_cache(t->md->dax_dev, true);
 
 	/* Ensure that all underlying devices are non-rotational. */
-	if (dm_table_all_devices_attribute(t, device_is_nonrot))
-		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
-	else
+	if (dm_table_any_dev_attr(t, device_is_rotational))
 		queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
+	else
+		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
 
 	if (!dm_table_supports_write_same(t))
 		q->limits.max_write_same_sectors = 0;
@@ -1876,8 +1878,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	/*
 	 * Some devices don't use blk_integrity but still want stable pages
 	 * because they do their own checksumming.
+	 * If any underlying device requires stable pages, a table must require
+	 * them as well.  Only targets that support iterate_devices are considered:
+	 * don't want error, zero, etc to require stable pages.
 	 */
-	if (dm_table_requires_stable_pages(t))
+	if (dm_table_any_dev_attr(t, device_requires_stable_pages))
 		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
 	else
 		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
@@ -1888,7 +1893,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
 	 * have it set.
 	 */
-	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
+	if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random))
 		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
 
 	/*
Signature · 1 line
2.27.0
author maintainer
#3 lore raw

Re: [PATCH 4.14.y 1/4] dm table: fix iterate_devices based device capability checks

Quoted 188 lines · Jeffle Xu

commit a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e upstream.

According to the definition of dm_iterate_devices_fn:
* This function must iterate through each section of device used by the
* target until it encounters a non-zero return code, which it then returns.
* Returns zero if no callout returned non-zero.

For some target type (e.g. dm-stripe), one call of iterate_devices() may iterate multiple underlying devices internally, in which case a non-zero return code returned by iterate_devices_callout_fn will stop the iteration in advance. No iterate_devices_callout_fn should return non-zero unless device iteration should stop.

Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and elevate it for reuse to stop iterating (and return non-zero) on the first device that causes iterate_devices_callout_fn to return non-zero. Use dm_table_any_dev_attr() to properly iterate through devices.

Rename device_is_nonrot() to device_is_rotational() and invert logic accordingly to fix improper disposition.

Fixes c3c4555edd10 ("dm table: clear add_random unless all devices have it set")
Fixes 4693c9668fdc ("dm table: propagate non rotational flag")
---
 drivers/md/dm-table.c | 97 +++++++++++++++++++++++--------------------
 1 file changed, 51 insertions(+), 46 deletions(-)
drivers/md/dm-table.c +51 -46
index c855ab2feb18..6fe720e2c6ba 100644
@@ -1351,6 +1351,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 	return &t->targets[(KEYS_PER_NODE * n) + k];
 }
 
+/*
+ * type->iterate_devices() should be called when the sanity check needs to
+ * iterate and check all underlying data devices. iterate_devices() will
+ * iterate all underlying data devices until it encounters a non-zero return
+ * code, returned by whether the input iterate_devices_callout_fn, or
+ * iterate_devices() itself internally.
+ *
+ * For some target type (e.g. dm-stripe), one call of iterate_devices() may
+ * iterate multiple underlying devices internally, in which case a non-zero
+ * return code returned by iterate_devices_callout_fn will stop the iteration
+ * in advance.
+ *
+ * Cases requiring _any_ underlying device supporting some kind of attribute,
+ * should use the iteration structure like dm_table_any_dev_attr(), or call
+ * it directly. @func should handle semantics of positive examples, e.g.
+ * capable of something.
+ *
+ * Cases requiring _all_ underlying devices supporting some kind of attribute,
+ * should use the iteration structure like dm_table_supports_nowait() or
+ * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
+ * uses an @anti_func that handle semantics of counter examples, e.g. not
+ * capable of something. So: return !dm_table_any_dev_attr(t, anti_func);
+ */
+static bool dm_table_any_dev_attr(struct dm_table *t,
+				  iterate_devices_callout_fn func)
+{
+	struct dm_target *ti;
+	unsigned int i;
+
+	for (i = 0; i < dm_table_get_num_targets(t); i++) {
+		ti = dm_table_get_target(t, i);
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, func, NULL))
+			return true;
+        }
+
+	return false;
+}
+
 static int count_device(struct dm_target *ti, struct dm_dev *dev,
 			sector_t start, sector_t len, void *data)
 {
@@ -1667,12 +1707,12 @@ static int dm_table_supports_dax_write_cache(struct dm_table *t)
 	return false;
 }
 
-static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
-			    sector_t start, sector_t len, void *data)
+static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
+				sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 
-	return q && blk_queue_nonrot(q);
+	return q && !blk_queue_nonrot(q);
 }
 
 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
@@ -1691,23 +1731,6 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
 	return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
 }
 
-static bool dm_table_all_devices_attribute(struct dm_table *t,
-					   iterate_devices_callout_fn func)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (!ti->type->iterate_devices ||
-		    !ti->type->iterate_devices(ti, func, NULL))
-			return false;
-	}
-
-	return true;
-}
-
 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
 					 sector_t start, sector_t len, void *data)
 {
@@ -1804,27 +1827,6 @@ static int device_requires_stable_pages(struct dm_target *ti,
 	return q && bdi_cap_stable_pages_required(q->backing_dev_info);
 }
 
-/*
- * If any underlying device requires stable pages, a table must require
- * them as well.  Only targets that support iterate_devices are considered:
- * don't want error, zero, etc to require stable pages.
- */
-static bool dm_table_requires_stable_pages(struct dm_table *t)
-{
-	struct dm_target *ti;
-	unsigned i;
-
-	for (i = 0; i < dm_table_get_num_targets(t); i++) {
-		ti = dm_table_get_target(t, i);
-
-		if (ti->type->iterate_devices &&
-		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
-			return true;
-	}
-
-	return false;
-}
-
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 			       struct queue_limits *limits)
 {
@@ -1856,10 +1858,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 		dax_write_cache(t->md->dax_dev, true);
 
 	/* Ensure that all underlying devices are non-rotational. */
-	if (dm_table_all_devices_attribute(t, device_is_nonrot))
-		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
-	else
+	if (dm_table_any_dev_attr(t, device_is_rotational))
 		queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
+	else
+		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
 
 	if (!dm_table_supports_write_same(t))
 		q->limits.max_write_same_sectors = 0;
@@ -1876,8 +1878,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	/*
 	 * Some devices don't use blk_integrity but still want stable pages
 	 * because they do their own checksumming.
+	 * If any underlying device requires stable pages, a table must require
+	 * them as well.  Only targets that support iterate_devices are considered:
+	 * don't want error, zero, etc to require stable pages.
 	 */
-	if (dm_table_requires_stable_pages(t))
+	if (dm_table_any_dev_attr(t, device_requires_stable_pages))
 		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
 	else
 		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
@@ -1888,7 +1893,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
 	 * have it set.
 	 */
-	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
+	if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random))
 		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
 
 	/*
Signature · 1 line
2.27.0

Breaks the build :(