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Message-Id: <99F35207-7E6C-498E-9F4F-05569781B0C0@dilger.ca>
Date: Thu, 12 Jan 2023 01:32:16 -0700
From: Andreas Dilger <adilger@...ger.ca>
To: Li Dongyang <dongyangli@....com>
Cc: linux-ext4@...r.kernel.org
Subject: Re: [PATCH] e2fsck: optimize clone_file on large devices
On Dec 19, 2022, at 6:05 AM, Li Dongyang <dongyangli@....com> wrote:
>
> 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@....com>
Reviewed-by: Andreas Dilger <adilger@...ger.ca>
> ---
> e2fsck/pass1b.c | 73 ++++++-------------------------------
> tests/f_dup_resize/expect.1 | 3 +-
> 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
>
> --
> 2.37.3
>
Cheers, Andreas
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