1 files changed, 41 insertions, 28 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 454d5612641e..f44f668e407f 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1456,9 +1456,8 @@ static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
 		return 0;
 	}
 
-	block++;
-	pnum = block / blocks_per_page;
-	page = find_or_create_page(inode->i_mapping, pnum, gfp);
+	/* blocks_per_page == 1, hence we need another page for the buddy */
+	page = find_or_create_page(inode->i_mapping, block + 1, gfp);
 	if (!page)
 		return -ENOMEM;
 	BUG_ON(page->mapping != inode->i_mapping);
@@ -1958,8 +1957,7 @@ done:
 static int mb_find_extent(struct ext4_buddy *e4b, int block,
 				int needed, struct ext4_free_extent *ex)
 {
-	int next = block;
-	int max, order;
+	int max, order, next;
 	void *buddy;
 
 	assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
@@ -1977,16 +1975,12 @@ static int mb_find_extent(struct ext4_buddy *e4b, int block,
 
 	/* find actual order */
 	order = mb_find_order_for_block(e4b, block);
-	block = block >> order;
 
-	ex->fe_len = 1 << order;
-	ex->fe_start = block << order;
+	ex->fe_len = (1 << order) - (block & ((1 << order) - 1));
+	ex->fe_start = block;
 	ex->fe_group = e4b->bd_group;
 
-	/* calc difference from given start */
-	next = next - ex->fe_start;
-	ex->fe_len -= next;
-	ex->fe_start += next;
+	block = block >> order;
 
 	while (needed > ex->fe_len &&
 	       mb_find_buddy(e4b, order, &max)) {
@@ -2895,14 +2889,19 @@ repeat:
 			ac->ac_groups_scanned++;
 			if (cr == CR_POWER2_ALIGNED)
 				ext4_mb_simple_scan_group(ac, &e4b);
-			else if ((cr == CR_GOAL_LEN_FAST ||
-				 cr == CR_BEST_AVAIL_LEN) &&
-				 sbi->s_stripe &&
-				 !(ac->ac_g_ex.fe_len %
-				 EXT4_B2C(sbi, sbi->s_stripe)))
-				ext4_mb_scan_aligned(ac, &e4b);
-			else
-				ext4_mb_complex_scan_group(ac, &e4b);
+			else {
+				bool is_stripe_aligned = sbi->s_stripe &&
+					!(ac->ac_g_ex.fe_len %
+					  EXT4_B2C(sbi, sbi->s_stripe));
+
+				if ((cr == CR_GOAL_LEN_FAST ||
+				     cr == CR_BEST_AVAIL_LEN) &&
+				    is_stripe_aligned)
+					ext4_mb_scan_aligned(ac, &e4b);
+
+				if (ac->ac_status == AC_STATUS_CONTINUE)
+					ext4_mb_complex_scan_group(ac, &e4b);
+			}
 
 			ext4_unlock_group(sb, group);
 			ext4_mb_unload_buddy(&e4b);
@@ -4478,6 +4477,10 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
 	start = max(start, rounddown(ac->ac_o_ex.fe_logical,
 			(ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
 
+	/* avoid unnecessary preallocation that may trigger assertions */
+	if (start + size > EXT_MAX_BLOCKS)
+		size = EXT_MAX_BLOCKS - start;
+
 	/* don't cover already allocated blocks in selected range */
 	if (ar->pleft && start <= ar->lleft) {
 		size -= ar->lleft + 1 - start;
@@ -6731,11 +6734,16 @@ __acquires(bitlock)
 static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb,
 					   ext4_group_t grp)
 {
-	if (grp < ext4_get_groups_count(sb))
-		return EXT4_CLUSTERS_PER_GROUP(sb) - 1;
-	return (ext4_blocks_count(EXT4_SB(sb)->s_es) -
-		ext4_group_first_block_no(sb, grp) - 1) >>
-					EXT4_CLUSTER_BITS(sb);
+	unsigned long nr_clusters_in_group;
+
+	if (grp < (ext4_get_groups_count(sb) - 1))
+		nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb);
+	else
+		nr_clusters_in_group = (ext4_blocks_count(EXT4_SB(sb)->s_es) -
+					ext4_group_first_block_no(sb, grp))
+				       >> EXT4_CLUSTER_BITS(sb);
+
+	return nr_clusters_in_group - 1;
 }
 
 static bool ext4_trim_interrupted(void)
@@ -6749,13 +6757,15 @@ static int ext4_try_to_trim_range(struct super_block *sb,
 __acquires(ext4_group_lock_ptr(sb, e4b->bd_group))
 __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
 {
-	ext4_grpblk_t next, count, free_count;
+	ext4_grpblk_t next, count, free_count, last, origin_start;
 	bool set_trimmed = false;
 	void *bitmap;
 
+	last = ext4_last_grp_cluster(sb, e4b->bd_group);
 	bitmap = e4b->bd_bitmap;
-	if (start == 0 && max >= ext4_last_grp_cluster(sb, e4b->bd_group))
+	if (start == 0 && max >= last)
 		set_trimmed = true;
+	origin_start = start;
 	start = max(e4b->bd_info->bb_first_free, start);
 	count = 0;
 	free_count = 0;
@@ -6764,7 +6774,10 @@ __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
 		start = mb_find_next_zero_bit(bitmap, max + 1, start);
 		if (start > max)
 			break;
-		next = mb_find_next_bit(bitmap, max + 1, start);
+
+		next = mb_find_next_bit(bitmap, last + 1, start);
+		if (origin_start == 0 && next >= last)
+			set_trimmed = true;
 
 		if ((next - start) >= minblocks) {
 			int ret = ext4_trim_extent(sb, start, next - start, e4b);