e2fsck: optimize clone_file on large devices

When cloning multiply-claimed blocks for an inode,
clone_file() uses ext2fs_block_iterate3() to iterate
every block calling clone_file_block().
clone_file_block() calls check_if_fs_cluster(), even
the block is not on the block_dup_map, which could take
a long time on a large device.

Only check if it's metadata block when we need to clone
it.

Test block_metadata_map in check_if_fs_block()
and check_if_fs_cluster(), so we don't need to go over
each bg every time. The metadata blocks are already
marked in the bitmap.

Before this patch on a 500TB device with 3 files having
3 multiply-claimed blocks between them, pass1b is stuck
for more than 48 hours without progressing,
before e2fsck was terminated.
After this patch pass1b could finish in 180 seconds.

Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

2 files changed, 13 insertions, 63 deletions

diff --git a/e2fsck/pass1b.c b/e2fsck/pass1b.c
index 92c746c1d..950af5be0 100644
--- a/e2fsck/pass1b.c
+++ b/e2fsck/pass1b.c
@@ -90,7 +90,7 @@ static void delete_file(e2fsck_t ctx, ext2_ino_t ino,
 			struct dup_inode *dp, char *block_buf);
 static errcode_t clone_file(e2fsck_t ctx, ext2_ino_t ino,
 			    struct dup_inode *dp, char* block_buf);
-static int check_if_fs_block(e2fsck_t ctx, blk64_t test_block);
+static int check_if_fs_block(e2fsck_t ctx, blk64_t block);
 static int check_if_fs_cluster(e2fsck_t ctx, blk64_t cluster);
 
 static void pass1b(e2fsck_t ctx, char *block_buf);
@@ -815,8 +815,6 @@ static int clone_file_block(ext2_filsys fs,
 		should_write = 0;
 
 	c = EXT2FS_B2C(fs, blockcnt);
-	if (check_if_fs_cluster(ctx, EXT2FS_B2C(fs, *block_nr)))
-		is_meta = 1;
 
 	if (c == cs->dup_cluster && cs->alloc_block) {
 		new_block = cs->alloc_block;
@@ -894,6 +892,8 @@ cluster_alloc_ok:
 				return BLOCK_ABORT;
 			}
 		}
+		if (check_if_fs_cluster(ctx, EXT2FS_B2C(fs, *block_nr)))
+			is_meta = 1;
 		cs->save_dup_cluster = (is_meta ? NULL : p);
 		cs->save_blocknr = *block_nr;
 		*block_nr = new_block;
@@ -1021,37 +1021,9 @@ errout:
  * This routine returns 1 if a block overlaps with one of the superblocks,
  * group descriptors, inode bitmaps, or block bitmaps.
  */
-static int check_if_fs_block(e2fsck_t ctx, blk64_t test_block)
+static int check_if_fs_block(e2fsck_t ctx, blk64_t block)
 {
-	ext2_filsys fs = ctx->fs;
-	blk64_t	first_block;
-	dgrp_t	i;
-
-	first_block = fs->super->s_first_data_block;
-	for (i = 0; i < fs->group_desc_count; i++) {
-
-		/* Check superblocks/block group descriptors */
-		if (ext2fs_bg_has_super(fs, i)) {
-			if (test_block >= first_block &&
-			    (test_block <= first_block + fs->desc_blocks))
-				return 1;
-		}
-
-		/* Check the inode table */
-		if ((ext2fs_inode_table_loc(fs, i)) &&
-		    (test_block >= ext2fs_inode_table_loc(fs, i)) &&
-		    (test_block < (ext2fs_inode_table_loc(fs, i) +
-				   fs->inode_blocks_per_group)))
-			return 1;
-
-		/* Check the bitmap blocks */
-		if ((test_block == ext2fs_block_bitmap_loc(fs, i)) ||
-		    (test_block == ext2fs_inode_bitmap_loc(fs, i)))
-			return 1;
-
-		first_block += fs->super->s_blocks_per_group;
-	}
-	return 0;
+	return ext2fs_test_block_bitmap2(ctx->block_metadata_map, block);
 }
 
 /*
@@ -1061,37 +1033,14 @@ static int check_if_fs_block(e2fsck_t ctx, blk64_t test_block)
 static int check_if_fs_cluster(e2fsck_t ctx, blk64_t cluster)
 {
 	ext2_filsys fs = ctx->fs;
-	blk64_t	first_block;
-	dgrp_t	i;
-
-	first_block = fs->super->s_first_data_block;
-	for (i = 0; i < fs->group_desc_count; i++) {
-
-		/* Check superblocks/block group descriptors */
-		if (ext2fs_bg_has_super(fs, i)) {
-			if (cluster >= EXT2FS_B2C(fs, first_block) &&
-			    (cluster <= EXT2FS_B2C(fs, first_block +
-						   fs->desc_blocks)))
-				return 1;
-		}
+	blk64_t	block = EXT2FS_C2B(fs, cluster);
+	int i;
 
-		/* Check the inode table */
-		if ((ext2fs_inode_table_loc(fs, i)) &&
-		    (cluster >= EXT2FS_B2C(fs,
-					   ext2fs_inode_table_loc(fs, i))) &&
-		    (cluster <= EXT2FS_B2C(fs,
-					   ext2fs_inode_table_loc(fs, i) +
-					   fs->inode_blocks_per_group - 1)))
+	for (i = 0; i < EXT2FS_CLUSTER_RATIO(fs); i++) {
+		if (ext2fs_test_block_bitmap2(ctx->block_metadata_map,
+					      block + i))
 			return 1;
-
-		/* Check the bitmap blocks */
-		if ((cluster == EXT2FS_B2C(fs,
-					   ext2fs_block_bitmap_loc(fs, i))) ||
-		    (cluster == EXT2FS_B2C(fs,
-					   ext2fs_inode_bitmap_loc(fs, i))))
-			return 1;
-
-		first_block += fs->super->s_blocks_per_group;
 	}
+
 	return 0;
 }
diff --git a/tests/f_dup_resize/expect.1 b/tests/f_dup_resize/expect.1
index e0d869795..8a2764d32 100644
--- a/tests/f_dup_resize/expect.1
+++ b/tests/f_dup_resize/expect.1
@@ -11,7 +11,8 @@ Pass 1D: Reconciling multiply-claimed blocks
 (There are 1 inodes containing multiply-claimed blocks.)
 
 File /debugfs (inode #12, mod time Mon Apr 11 00:00:00 2005) 
-  has 4 multiply-claimed block(s), shared with 1 file(s):
+  has 4 multiply-claimed block(s), shared with 2 file(s):
+	<filesystem metadata>
 	<The group descriptor inode> (inode #7, mod time Mon Apr 11 06:13:20 2005)
 Clone multiply-claimed blocks? yes