linux-ext4 - [RFCv1 17/72] libext2fs: Add support for ext2fs_test_block_bitmap_range2

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Date:   Mon,  7 Nov 2022 17:51:05 +0530
From:   "Ritesh Harjani (IBM)" <ritesh.list@...il.com>
To:     Theodore Ts'o <tytso@....edu>
Cc:     linux-ext4@...r.kernel.org,
        Harshad Shirwadkar <harshadshirwadkar@...il.com>,
        Wang Shilong <wshilong@....com>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Li Xi <lixi@....com>, Ritesh Harjani <ritesh.list@...il.com>
Subject: [RFCv1 17/72] libext2fs: Add support for ext2fs_test_block_bitmap_range2_valid()

From: Wang Shilong <wshilong@....com>

This adds the support in libext2fs to query whether the block range is
valid or not (within range) given the block bitmap.
Also to avoid duplicate warning messages in case of invalid blocks.

This will be later used in pass1 of e2fsck is_blocks_used() function to
check whether the given block range is valid or not to avoid duplicate
warning resulting from ext2fs_test_block_bitmap_range2()

Signed-off-by: Wang Shilong <wshilong@....com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@...il.com>
---
 lib/ext2fs/bitops.h       |  2 ++
 lib/ext2fs/gen_bitmap64.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/lib/ext2fs/bitops.h b/lib/ext2fs/bitops.h
index 505b3c9c..1facc8dd 100644
--- a/lib/ext2fs/bitops.h
+++ b/lib/ext2fs/bitops.h
@@ -120,6 +120,8 @@ extern int ext2fs_test_block_bitmap_range(ext2fs_block_bitmap bitmap,
 extern void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map);
 extern __u32 ext2fs_get_generic_bitmap_start(ext2fs_generic_bitmap bitmap);
 extern __u32 ext2fs_get_generic_bitmap_end(ext2fs_generic_bitmap bitmap);
+extern int ext2fs_test_block_bitmap_range2_valid(ext2fs_block_bitmap bitmap,
+						blk64_t block, unsigned int num);
 
 /* 64-bit versions */
 
diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
index c31f942f..a9637cb5 100644
--- a/lib/ext2fs/gen_bitmap64.c
+++ b/lib/ext2fs/gen_bitmap64.c
@@ -731,6 +731,39 @@ int ext2fs_test_block_bitmap_range2(ext2fs_block_bitmap gen_bmap,
 	return bmap->bitmap_ops->test_clear_bmap_extent(bmap, block, num);
 }
 
+int ext2fs_test_block_bitmap_range2_valid(ext2fs_block_bitmap bitmap,
+					  blk64_t block, unsigned int num)
+{
+	ext2fs_generic_bitmap_64 bmap = (ext2fs_generic_bitmap_64)bitmap;
+	__u64	end = block + num;
+
+	if (!bmap)
+		return 0;
+
+	if (EXT2FS_IS_32_BITMAP(bmap)) {
+		if ((block & ~0xffffffffULL) ||
+		    ((block+num-1) & ~0xffffffffULL)) {
+			return 0;
+		}
+	}
+
+	if (!EXT2FS_IS_64_BITMAP(bmap))
+		return 0;
+
+	/* convert to clusters if necessary */
+	block >>= bmap->cluster_bits;
+	end += (1 << bmap->cluster_bits) - 1;
+	end >>= bmap->cluster_bits;
+	num = end - block;
+
+	if ((block < bmap->start) || (block > bmap->end) ||
+	    (block+num-1 > bmap->end))
+		return 0;
+
+	return 1;
+}
+
+
 void ext2fs_mark_block_bitmap_range2(ext2fs_block_bitmap gen_bmap,
 				     blk64_t block, unsigned int num)
 {
-- 
2.37.3