From 756a15f32338fdf0c562678694bc8991ad6afb90 Mon Sep 17 00:00:00 2001

From: Mateusz Grzonka <mateusz.grzonka@intel.com>

Date: Mon, 13 Jun 2022 12:00:09 +0200

Subject: [PATCH 19/83] imsm: Remove possibility for get_imsm_dev to return

 NULL

Returning NULL from get_imsm_dev or __get_imsm_dev will cause segfault.

Guarantee that it never happens.

Signed-off-by: Mateusz Grzonka <mateusz.grzonka@intel.com>

Signed-off-by: Jes Sorensen <jsorensen@fb.com>

---

 super-intel.c | 153 +++++++++++++++++++++++++-------------------------

 1 file changed, 78 insertions(+), 75 deletions(-)

diff --git a/super-intel.c b/super-intel.c

index ba3bd41f..3788feb9 100644

--- a/super-intel.c

+++ b/super-intel.c

@@ -851,6 +851,21 @@ static struct disk_info *get_disk_info(struct imsm_update_create_array *update)

 	return inf;

 }

+/**

+ * __get_imsm_dev() - Get device with index from imsm_super.

+ * @mpb: &imsm_super pointer, not NULL.

+ * @index: Device index.

+ *

+ * Function works as non-NULL, aborting in such a case,

+ * when NULL would be returned.

+ *

+ * Device index should be in range 0 up to num_raid_devs.

+ * Function assumes the index was already verified.

+ * Index must be valid, otherwise abort() is called.

+ *

+ * Return: Pointer to corresponding imsm_dev.

+ *

+ */

 static struct imsm_dev *__get_imsm_dev(struct imsm_super *mpb, __u8 index)

 {

 	int offset;

@@ -858,30 +873,47 @@ static struct imsm_dev *__get_imsm_dev(struct imsm_super *mpb, __u8 index)

 	void *_mpb = mpb;

 	if (index >= mpb->num_raid_devs)

-		return NULL;

+		goto error;

 	/* devices start after all disks */

 	offset = ((void *) &mpb->disk[mpb->num_disks]) - _mpb;

-	for (i = 0; i <= index; i++)

+	for (i = 0; i <= index; i++, offset += sizeof_imsm_dev(_mpb + offset, 0))

 		if (i == index)

 			return _mpb + offset;

-		else

-			offset += sizeof_imsm_dev(_mpb + offset, 0);

-

-	return NULL;

+error:

+	pr_err("cannot find imsm_dev with index %u in imsm_super\n", index);

+	abort();

 }

+/**

+ * get_imsm_dev() - Get device with index from intel_super.

+ * @super: &intel_super pointer, not NULL.

+ * @index: Device index.

+ *

+ * Function works as non-NULL, aborting in such a case,

+ * when NULL would be returned.

+ *

+ * Device index should be in range 0 up to num_raid_devs.

+ * Function assumes the index was already verified.

+ * Index must be valid, otherwise abort() is called.

+ *

+ * Return: Pointer to corresponding imsm_dev.

+ *

+ */

 static struct imsm_dev *get_imsm_dev(struct intel_super *super, __u8 index)

 {

 	struct intel_dev *dv;

 	if (index >= super->anchor->num_raid_devs)

-		return NULL;

+		goto error;

+

 	for (dv = super->devlist; dv; dv = dv->next)

 		if (dv->index == index)

 			return dv->dev;

-	return NULL;

+error:

+	pr_err("cannot find imsm_dev with index %u in intel_super\n", index);

+	abort();

 }

 static inline unsigned long long __le48_to_cpu(const struct bbm_log_block_addr

@@ -4364,8 +4396,7 @@ int check_mpb_migr_compatibility(struct intel_super *super)

 	for (i = 0; i < super->anchor->num_raid_devs; i++) {

 		struct imsm_dev *dev_iter = __get_imsm_dev(super->anchor, i);

-		if (dev_iter &&

-		    dev_iter->vol.migr_state == 1 &&

+		if (dev_iter->vol.migr_state == 1 &&

 		    dev_iter->vol.migr_type == MIGR_GEN_MIGR) {

 			/* This device is migrating */

 			map0 = get_imsm_map(dev_iter, MAP_0);

@@ -4514,8 +4545,6 @@ static void clear_hi(struct intel_super *super)

 	}

 	for (i = 0; i < mpb->num_raid_devs; ++i) {

 		struct imsm_dev *dev = get_imsm_dev(super, i);

-		if (!dev)

-			return;

 		for (n = 0; n < 2; ++n) {

 			struct imsm_map *map = get_imsm_map(dev, n);

 			if (!map)

@@ -5836,7 +5865,7 @@ static int add_to_super_imsm_volume(struct supertype *st, mdu_disk_info_t *dk,

 		struct imsm_dev *_dev = __get_imsm_dev(mpb, 0);

 		_disk = __get_imsm_disk(mpb, dl->index);

-		if (!_dev || !_disk) {

+		if (!_disk) {

 			pr_err("BUG mpb setup error\n");

 			return 1;

 		}

@@ -6171,10 +6200,10 @@ static int write_super_imsm(struct supertype *st, int doclose)

 	for (i = 0; i < mpb->num_raid_devs; i++) {

 		struct imsm_dev *dev = __get_imsm_dev(mpb, i);

 		struct imsm_dev *dev2 = get_imsm_dev(super, i);

-		if (dev && dev2) {

-			imsm_copy_dev(dev, dev2);

-			mpb_size += sizeof_imsm_dev(dev, 0);

-		}

+

+		imsm_copy_dev(dev, dev2);

+		mpb_size += sizeof_imsm_dev(dev, 0);

+

 		if (is_gen_migration(dev2))

 			clear_migration_record = 0;

 	}

@@ -9033,29 +9062,26 @@ static int imsm_rebuild_allowed(struct supertype *cont, int dev_idx, int failed)

 	__u8 state;

 	dev2 = get_imsm_dev(cont->sb, dev_idx);

-	if (dev2) {

-		state = imsm_check_degraded(cont->sb, dev2, failed, MAP_0);

-		if (state == IMSM_T_STATE_FAILED) {

-			map = get_imsm_map(dev2, MAP_0);

-			if (!map)

-				return 1;

-			for (slot = 0; slot < map->num_members; slot++) {

-				/*

-				 * Check if failed disks are deleted from intel

-				 * disk list or are marked to be deleted

-				 */

-				idx = get_imsm_disk_idx(dev2, slot, MAP_X);

-				idisk = get_imsm_dl_disk(cont->sb, idx);

-				/*

-				 * Do not rebuild the array if failed disks

-				 * from failed sub-array are not removed from

-				 * container.

-				 */

-				if (idisk &&

-				    is_failed(&idisk->disk) &&

-				    (idisk->action != DISK_REMOVE))

-					return 0;

-			}

+

+	state = imsm_check_degraded(cont->sb, dev2, failed, MAP_0);

+	if (state == IMSM_T_STATE_FAILED) {

+		map = get_imsm_map(dev2, MAP_0);

+		for (slot = 0; slot < map->num_members; slot++) {

+			/*

+			 * Check if failed disks are deleted from intel

+			 * disk list or are marked to be deleted

+			 */

+			idx = get_imsm_disk_idx(dev2, slot, MAP_X);

+			idisk = get_imsm_dl_disk(cont->sb, idx);

+			/*

+			 * Do not rebuild the array if failed disks

+			 * from failed sub-array are not removed from

+			 * container.

+			 */

+			if (idisk &&

+			    is_failed(&idisk->disk) &&

+			    (idisk->action != DISK_REMOVE))

+				return 0;

 		}

 	}

 	return 1;

@@ -10089,7 +10115,6 @@ static void imsm_process_update(struct supertype *st,

 		int victim = u->dev_idx;

 		struct active_array *a;

 		struct intel_dev **dp;

-		struct imsm_dev *dev;

 		/* sanity check that we are not affecting the uuid of

 		 * active arrays, or deleting an active array

@@ -10105,8 +10130,7 @@ static void imsm_process_update(struct supertype *st,

 		 * is active in the container, so checking

 		 * mpb->num_raid_devs is just extra paranoia

 		 */

-		dev = get_imsm_dev(super, victim);

-		if (a || !dev || mpb->num_raid_devs == 1) {

+		if (a || mpb->num_raid_devs == 1 || victim >= super->anchor->num_raid_devs) {

 			dprintf("failed to delete subarray-%d\n", victim);

 			break;

 		}

@@ -10140,7 +10164,7 @@ static void imsm_process_update(struct supertype *st,

 			if (a->info.container_member == target)

 				break;

 		dev = get_imsm_dev(super, u->dev_idx);

-		if (a || !dev || !check_name(super, name, 1)) {

+		if (a || !check_name(super, name, 1)) {

 			dprintf("failed to rename subarray-%d\n", target);

 			break;

 		}

@@ -10169,10 +10193,6 @@ static void imsm_process_update(struct supertype *st,

 		struct imsm_update_rwh_policy *u = (void *)update->buf;

 		int target = u->dev_idx;

 		struct imsm_dev *dev = get_imsm_dev(super, target);

-		if (!dev) {

-			dprintf("could not find subarray-%d\n", target);

-			break;

-		}

 		if (dev->rwh_policy != u->new_policy) {

 			dev->rwh_policy = u->new_policy;

@@ -11397,8 +11417,10 @@ static int imsm_create_metadata_update_for_migration(

 {

 	struct intel_super *super = st->sb;

 	int update_memory_size;

+	int current_chunk_size;

 	struct imsm_update_reshape_migration *u;

-	struct imsm_dev *dev;

+	struct imsm_dev *dev = get_imsm_dev(super, super->current_vol);

+	struct imsm_map *map = get_imsm_map(dev, MAP_0);

 	int previous_level = -1;

 	dprintf("(enter) New Level = %i\n", geo->level);

@@ -11415,23 +11437,15 @@ static int imsm_create_metadata_update_for_migration(

 	u->new_disks[0] = -1;

 	u->new_chunksize = -1;

-	dev = get_imsm_dev(super, u->subdev);

-	if (dev) {

-		struct imsm_map *map;

+	current_chunk_size = __le16_to_cpu(map->blocks_per_strip) / 2;

-		map = get_imsm_map(dev, MAP_0);

-		if (map) {

-			int current_chunk_size =

-				__le16_to_cpu(map->blocks_per_strip) / 2;

-

-			if (geo->chunksize != current_chunk_size) {

-				u->new_chunksize = geo->chunksize / 1024;

-				dprintf("imsm: chunk size change from %i to %i\n",

-					current_chunk_size, u->new_chunksize);

-			}

-			previous_level = map->raid_level;

-		}

+	if (geo->chunksize != current_chunk_size) {

+		u->new_chunksize = geo->chunksize / 1024;

+		dprintf("imsm: chunk size change from %i to %i\n",

+			current_chunk_size, u->new_chunksize);

 	}

+	previous_level = map->raid_level;

+

 	if (geo->level == 5 && previous_level == 0) {

 		struct mdinfo *spares = NULL;

@@ -12519,9 +12533,6 @@ static int validate_internal_bitmap_imsm(struct supertype *st)

 	unsigned long long offset;

 	struct dl *d;

-	if (!dev)

-		return -1;

-

 	if (dev->rwh_policy != RWH_BITMAP)

 		return 0;

@@ -12567,16 +12578,8 @@ static int add_internal_bitmap_imsm(struct supertype *st, int *chunkp,

 		return -1;

 	dev = get_imsm_dev(super, vol_idx);

-

-	if (!dev) {

-		dprintf("cannot find the device for volume index %d\n",

-			vol_idx);

-		return -1;

-	}

 	dev->rwh_policy = RWH_BITMAP;

-

 	*chunkp = calculate_bitmap_chunksize(st, dev);

-

 	return 0;

 }

-- 

2.38.1