Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 749ec26..54c089a 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -493,7 +493,7 @@
 	void *p;
 	int r;
 
-	if (bm->read_only)
+	if (dm_bm_is_read_only(bm))
 		return -EPERM;
 
 	p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result);
@@ -562,7 +562,7 @@
 	struct buffer_aux *aux;
 	void *p;
 
-	if (bm->read_only)
+	if (dm_bm_is_read_only(bm))
 		return -EPERM;
 
 	p = dm_bufio_new(bm->bufio, b, (struct dm_buffer **) result);
@@ -602,7 +602,7 @@
 
 int dm_bm_flush(struct dm_block_manager *bm)
 {
-	if (bm->read_only)
+	if (dm_bm_is_read_only(bm))
 		return -EPERM;
 
 	return dm_bufio_write_dirty_buffers(bm->bufio);
@@ -616,19 +616,21 @@
 
 bool dm_bm_is_read_only(struct dm_block_manager *bm)
 {
-	return bm->read_only;
+	return (bm ? bm->read_only : true);
 }
 EXPORT_SYMBOL_GPL(dm_bm_is_read_only);
 
 void dm_bm_set_read_only(struct dm_block_manager *bm)
 {
-	bm->read_only = true;
+	if (bm)
+		bm->read_only = true;
 }
 EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
 
 void dm_bm_set_read_write(struct dm_block_manager *bm)
 {
-	bm->read_only = false;
+	if (bm)
+		bm->read_only = false;
 }
 EXPORT_SYMBOL_GPL(dm_bm_set_read_write);
 
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index a240990..5673f8e 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -34,12 +34,12 @@
 	__le32 max_entries;
 	__le32 value_size;
 	__le32 padding;
-} __packed;
+} __attribute__((packed, aligned(8)));
 
 struct btree_node {
 	struct node_header header;
 	__le64 keys[0];
-} __packed;
+} __attribute__((packed, aligned(8)));
 
 
 /*
diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c
index 21ea537..9e4d121 100644
--- a/drivers/md/persistent-data/dm-btree-remove.c
+++ b/drivers/md/persistent-data/dm-btree-remove.c
@@ -203,7 +203,13 @@
 	struct btree_node *right = r->n;
 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
 	uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
-	unsigned threshold = 2 * merge_threshold(left) + 1;
+	/*
+	 * Ensure the number of entries in each child will be greater
+	 * than or equal to (max_entries / 3 + 1), so no matter which
+	 * child is used for removal, the number will still be not
+	 * less than (max_entries / 3).
+	 */
+	unsigned int threshold = 2 * (merge_threshold(left) + 1);
 
 	if (nr_left + nr_right < threshold) {
 		/*
@@ -543,7 +549,8 @@
 		delete_at(n, index);
 	}
 
-	*new_root = shadow_root(&spine);
+	if (!r)
+		*new_root = shadow_root(&spine);
 	exit_shadow_spine(&spine);
 
 	return r;
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index bd68f6f..a213bf1 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -339,6 +339,8 @@
 	 */
 	begin = do_div(index_begin, ll->entries_per_block);
 	end = do_div(end, ll->entries_per_block);
+	if (end == 0)
+		end = ll->entries_per_block;
 
 	for (i = index_begin; i < index_end; i++, begin = 0) {
 		struct dm_block *blk;
@@ -380,6 +382,33 @@
 	return -ENOSPC;
 }
 
+int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
+	                         dm_block_t begin, dm_block_t end, dm_block_t *b)
+{
+	int r;
+	uint32_t count;
+
+	do {
+		r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);
+		if (r)
+			break;
+
+		/* double check this block wasn't used in the old transaction */
+		if (*b >= old_ll->nr_blocks)
+			count = 0;
+		else {
+			r = sm_ll_lookup(old_ll, *b, &count);
+			if (r)
+				break;
+
+			if (count)
+				begin = *b + 1;
+		}
+	} while (count);
+
+	return r;
+}
+
 static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
 			int (*mutator)(void *context, uint32_t old, uint32_t *new),
 			void *context, enum allocation_event *ev)
diff --git a/drivers/md/persistent-data/dm-space-map-common.h b/drivers/md/persistent-data/dm-space-map-common.h
index b3078d5..87e1790 100644
--- a/drivers/md/persistent-data/dm-space-map-common.h
+++ b/drivers/md/persistent-data/dm-space-map-common.h
@@ -33,7 +33,7 @@
 	__le64 blocknr;
 	__le32 nr_free;
 	__le32 none_free_before;
-} __packed;
+} __attribute__ ((packed, aligned(8)));
 
 
 #define MAX_METADATA_BITMAPS 255
@@ -43,7 +43,7 @@
 	__le64 blocknr;
 
 	struct disk_index_entry index[MAX_METADATA_BITMAPS];
-} __packed;
+} __attribute__ ((packed, aligned(8)));
 
 struct ll_disk;
 
@@ -86,7 +86,7 @@
 	__le64 nr_allocated;
 	__le64 bitmap_root;
 	__le64 ref_count_root;
-} __packed;
+} __attribute__ ((packed, aligned(8)));
 
 #define ENTRIES_PER_BYTE 4
 
@@ -94,7 +94,7 @@
 	__le32 csum;
 	__le32 not_used;
 	__le64 blocknr;
-} __packed;
+} __attribute__ ((packed, aligned(8)));
 
 enum allocation_event {
 	SM_NONE,
@@ -109,6 +109,8 @@
 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result);
 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 			  dm_block_t end, dm_block_t *result);
+int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
+	                         dm_block_t begin, dm_block_t end, dm_block_t *result);
 int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, enum allocation_event *ev);
 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev);
diff --git a/drivers/md/persistent-data/dm-space-map-disk.c b/drivers/md/persistent-data/dm-space-map-disk.c
index 32adf6b..e0acae7 100644
--- a/drivers/md/persistent-data/dm-space-map-disk.c
+++ b/drivers/md/persistent-data/dm-space-map-disk.c
@@ -167,8 +167,18 @@
 	enum allocation_event ev;
 	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
 
-	/* FIXME: we should loop round a couple of times */
-	r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
+	/*
+	 * Any block we allocate has to be free in both the old and current ll.
+	 */
+	r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b);
+	if (r == -ENOSPC) {
+		/*
+		 * There's no free block between smd->begin and the end of the metadata device.
+		 * We search before smd->begin in case something has been freed.
+		 */
+		r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b);
+	}
+
 	if (r)
 		return r;
 
@@ -197,7 +207,6 @@
 		return r;
 
 	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
-	smd->begin = 0;
 	smd->nr_allocated_this_transaction = 0;
 
 	r = sm_disk_get_nr_free(sm, &nr_free);
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 2532858..da439ac 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -448,7 +448,18 @@
 	enum allocation_event ev;
 	struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 
-	r = sm_ll_find_free_block(&smm->old_ll, smm->begin, smm->old_ll.nr_blocks, b);
+	/*
+	 * Any block we allocate has to be free in both the old and current ll.
+	 */
+	r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, smm->begin, smm->ll.nr_blocks, b);
+	if (r == -ENOSPC) {
+		/*
+		 * There's no free block between smm->begin and the end of the metadata device.
+		 * We search before smm->begin in case something has been freed.
+		 */
+		r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, 0, smm->begin, b);
+	}
+
 	if (r)
 		return r;
 
@@ -500,7 +511,6 @@
 		return r;
 
 	memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
-	smm->begin = 0;
 	smm->allocated_this_transaction = 0;
 
 	return 0;