Commit a7a79c29 authored by Jason Yan's avatar Jason Yan Committed by Theodore Ts'o
Browse files

ext4: unify the ext4 super block loading operation 



Now we load the super block from the disk in two steps. First we load
the super block with the default block size(EXT4_MIN_BLOCK_SIZE). Second
we load the super block with the real block size. The second step is a
little far from the first step. This patch move these two steps together
in a new function.

Signed-off-by: default avatarJason Yan <yanaijie@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220916141527.1012715-15-yanaijie@huawei.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent a5991e53

fs/ext4/super.c

+106 −80
Original line number Diff line number Diff line
@@ -4920,39 +4920,21 @@ static int ext4_journal_data_mode_check(struct super_block *sb) 
	return 0;

}



static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)

static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,

			   int silent)

{

	struct buffer_head *bh;

	struct ext4_super_block *es = NULL;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct flex_groups **flex_groups;

	ext4_fsblk_t block;

	struct ext4_super_block *es;

	ext4_fsblk_t logical_sb_block;

	unsigned long offset = 0;

	struct inode *root;

	int ret = -ENOMEM;

	struct buffer_head *bh;

	int ret = -EINVAL;

	int blocksize;

	unsigned int i;

	int needs_recovery, has_huge_files;

	int err = 0;

	ext4_group_t first_not_zeroed;

	struct ext4_fs_context *ctx = fc->fs_private;

	int silent = fc->sb_flags & SB_SILENT;



	/* Set defaults for the variables that will be set during parsing */

	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))

		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;



	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;

	sbi->s_sectors_written_start =

		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);



	/* -EINVAL is default */

	ret = -EINVAL;

	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);

	if (!blocksize) {

		ext4_msg(sb, KERN_ERR, "unable to set blocksize");

		goto out_fail;

		return -EINVAL;

	}



	/*
@@ -4969,8 +4951,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);

	if (IS_ERR(bh)) {

		ext4_msg(sb, KERN_ERR, "unable to read superblock");

		ret = PTR_ERR(bh);

		goto out_fail;

		return PTR_ERR(bh);

	}

	/*

	 * Note: s_es must be initialized as soon as possible because
@@ -4982,9 +4963,106 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
	if (sb->s_magic != EXT4_SUPER_MAGIC) {

		if (!silent)

			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");

		goto failed_mount;

		goto out;

	}



	if (le32_to_cpu(es->s_log_block_size) >

	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {

		ext4_msg(sb, KERN_ERR,

			 "Invalid log block size: %u",

			 le32_to_cpu(es->s_log_block_size));

		goto out;

	}

	if (le32_to_cpu(es->s_log_cluster_size) >

	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {

		ext4_msg(sb, KERN_ERR,

			 "Invalid log cluster size: %u",

			 le32_to_cpu(es->s_log_cluster_size));

		goto out;

	}



	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);



	/*

	 * If the default block size is not the same as the real block size,

	 * we need to reload it.

	 */

	if (sb->s_blocksize == blocksize) {

		*lsb = logical_sb_block;

		sbi->s_sbh = bh;

		return 0;

	}



	/*

	 * bh must be released before kill_bdev(), otherwise

	 * it won't be freed and its page also. kill_bdev()

	 * is called by sb_set_blocksize().

	 */

	brelse(bh);

	/* Validate the filesystem blocksize */

	if (!sb_set_blocksize(sb, blocksize)) {

		ext4_msg(sb, KERN_ERR, "bad block size %d",

				blocksize);

		bh = NULL;

		goto out;

	}



	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;

	offset = do_div(logical_sb_block, blocksize);

	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);

	if (IS_ERR(bh)) {

		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");

		ret = PTR_ERR(bh);

		bh = NULL;

		goto out;

	}

	es = (struct ext4_super_block *)(bh->b_data + offset);

	sbi->s_es = es;

	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {

		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");

		goto out;

	}

	*lsb = logical_sb_block;

	sbi->s_sbh = bh;

	return 0;

out:

	brelse(bh);

	return ret;

}



static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)

{

	struct ext4_super_block *es = NULL;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct flex_groups **flex_groups;

	ext4_fsblk_t block;

	ext4_fsblk_t logical_sb_block;

	struct inode *root;

	int ret = -ENOMEM;

	int blocksize;

	unsigned int i;

	int needs_recovery, has_huge_files;

	int err = 0;

	ext4_group_t first_not_zeroed;

	struct ext4_fs_context *ctx = fc->fs_private;

	int silent = fc->sb_flags & SB_SILENT;



	/* Set defaults for the variables that will be set during parsing */

	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))

		ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;



	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;

	sbi->s_sectors_written_start =

		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);



	/* -EINVAL is default */

	ret = -EINVAL;

	err = ext4_load_super(sb, &logical_sb_block, silent);

	if (err)

		goto out_fail;



	es = sbi->s_es;

	blocksize = sb->s_blocksize;

	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);



	err = ext4_init_metadata_csum(sb, es);
@@ -5005,23 +5083,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
	 */

	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;



	if (le32_to_cpu(es->s_log_block_size) >

	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {

		ext4_msg(sb, KERN_ERR,

			 "Invalid log block size: %u",

			 le32_to_cpu(es->s_log_block_size));

		goto failed_mount;

	}

	if (le32_to_cpu(es->s_log_cluster_size) >

	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {

		ext4_msg(sb, KERN_ERR,

			 "Invalid log cluster size: %u",

			 le32_to_cpu(es->s_log_cluster_size));

		goto failed_mount;

	}



	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);



	if (blocksize == PAGE_SIZE)

		set_opt(sb, DIOREAD_NOLOCK);
@@ -5088,40 +5149,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
		goto failed_mount;

	}



	if (sb->s_blocksize != blocksize) {

		/*

		 * bh must be released before kill_bdev(), otherwise

		 * it won't be freed and its page also. kill_bdev()

		 * is called by sb_set_blocksize().

		 */

		brelse(bh);

		/* Validate the filesystem blocksize */

		if (!sb_set_blocksize(sb, blocksize)) {

			ext4_msg(sb, KERN_ERR, "bad block size %d",

					blocksize);

			bh = NULL;

			goto failed_mount;

		}



		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;

		offset = do_div(logical_sb_block, blocksize);

		bh = ext4_sb_bread_unmovable(sb, logical_sb_block);

		if (IS_ERR(bh)) {

			ext4_msg(sb, KERN_ERR,

			       "Can't read superblock on 2nd try");

			ret = PTR_ERR(bh);

			bh = NULL;

			goto failed_mount;

		}

		es = (struct ext4_super_block *)(bh->b_data + offset);

		sbi->s_es = es;

		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {

			ext4_msg(sb, KERN_ERR,

			       "Magic mismatch, very weird!");

			goto failed_mount;

		}

	}



	has_huge_files = ext4_has_feature_huge_file(sb);

	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,

						      has_huge_files);
@@ -5158,7 +5185,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
	sbi->s_itb_per_group = sbi->s_inodes_per_group /

					sbi->s_inodes_per_block;

	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);

	sbi->s_sbh = bh;

	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;

	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));

	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
@@ -5595,7 +5621,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
#endif

	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);

	/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */

	brelse(bh);

	brelse(sbi->s_sbh);

	ext4_blkdev_remove(sbi);

out_fail:

	sb->s_fs_info = NULL;