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>

diff --git a/e2fsck/pass1b.c b/e2fsck/pass1b.c
index 92c746c1d448d37b1268c61c1b044b4418afebdc..950af5be0b7007ea55f2aaf69b359b7e3153e403 100644 (file)
--- 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 e0d8697954df01739688daafa598b143f93484ba..8a2764d32ce85bdfb24bdfc764c0e282a7c63756 100644 (file)
--- 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