forked from Minki/linux
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: Jason Yan <yanaijie@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220916141527.1012715-15-yanaijie@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Jason Yan
Theodore Ts'o
parent
a5991e539c
commit
a7a79c292a
204
fs/ext4/super.c
204
fs/ext4/super.c
@ -4920,15 +4920,123 @@ static int ext4_journal_data_mode_check(struct super_block *sb)
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return 0;
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}
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static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
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int silent)
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{
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct ext4_super_block *es;
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ext4_fsblk_t logical_sb_block;
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unsigned long offset = 0;
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struct buffer_head *bh;
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int ret = -EINVAL;
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int blocksize;
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blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
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if (!blocksize) {
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ext4_msg(sb, KERN_ERR, "unable to set blocksize");
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return -EINVAL;
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}
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/*
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* The ext4 superblock will not be buffer aligned for other than 1kB
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* block sizes. We need to calculate the offset from buffer start.
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*/
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if (blocksize != EXT4_MIN_BLOCK_SIZE) {
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logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
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offset = do_div(logical_sb_block, blocksize);
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} else {
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logical_sb_block = sbi->s_sb_block;
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}
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bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
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if (IS_ERR(bh)) {
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ext4_msg(sb, KERN_ERR, "unable to read superblock");
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return PTR_ERR(bh);
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}
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/*
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* Note: s_es must be initialized as soon as possible because
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* some ext4 macro-instructions depend on its value
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*/
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es = (struct ext4_super_block *) (bh->b_data + offset);
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sbi->s_es = es;
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sb->s_magic = le16_to_cpu(es->s_magic);
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if (sb->s_magic != EXT4_SUPER_MAGIC) {
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if (!silent)
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ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
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goto out;
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}
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if (le32_to_cpu(es->s_log_block_size) >
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(EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
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ext4_msg(sb, KERN_ERR,
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"Invalid log block size: %u",
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le32_to_cpu(es->s_log_block_size));
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goto out;
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}
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if (le32_to_cpu(es->s_log_cluster_size) >
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(EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
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ext4_msg(sb, KERN_ERR,
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"Invalid log cluster size: %u",
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le32_to_cpu(es->s_log_cluster_size));
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goto out;
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}
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blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
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/*
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* If the default block size is not the same as the real block size,
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* we need to reload it.
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*/
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if (sb->s_blocksize == blocksize) {
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*lsb = logical_sb_block;
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sbi->s_sbh = bh;
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return 0;
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}
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/*
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* bh must be released before kill_bdev(), otherwise
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* it won't be freed and its page also. kill_bdev()
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* is called by sb_set_blocksize().
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*/
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brelse(bh);
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/* Validate the filesystem blocksize */
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if (!sb_set_blocksize(sb, blocksize)) {
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ext4_msg(sb, KERN_ERR, "bad block size %d",
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blocksize);
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bh = NULL;
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goto out;
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}
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logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
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offset = do_div(logical_sb_block, blocksize);
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bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
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if (IS_ERR(bh)) {
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ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
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ret = PTR_ERR(bh);
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bh = NULL;
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goto out;
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}
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es = (struct ext4_super_block *)(bh->b_data + offset);
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sbi->s_es = es;
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if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
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ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
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goto out;
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}
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*lsb = logical_sb_block;
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sbi->s_sbh = bh;
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return 0;
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out:
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brelse(bh);
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return ret;
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}
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static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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{
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struct buffer_head *bh;
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struct ext4_super_block *es = NULL;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct flex_groups **flex_groups;
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ext4_fsblk_t block;
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ext4_fsblk_t logical_sb_block;
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unsigned long offset = 0;
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struct inode *root;
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int ret = -ENOMEM;
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int blocksize;
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@ -4949,42 +5057,12 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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/* -EINVAL is default */
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ret = -EINVAL;
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blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
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if (!blocksize) {
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ext4_msg(sb, KERN_ERR, "unable to set blocksize");
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err = ext4_load_super(sb, &logical_sb_block, silent);
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if (err)
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goto out_fail;
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}
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/*
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* The ext4 superblock will not be buffer aligned for other than 1kB
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* block sizes. We need to calculate the offset from buffer start.
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*/
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if (blocksize != EXT4_MIN_BLOCK_SIZE) {
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logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
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offset = do_div(logical_sb_block, blocksize);
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} else {
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logical_sb_block = sbi->s_sb_block;
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}
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bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
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if (IS_ERR(bh)) {
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ext4_msg(sb, KERN_ERR, "unable to read superblock");
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ret = PTR_ERR(bh);
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goto out_fail;
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}
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/*
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* Note: s_es must be initialized as soon as possible because
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* some ext4 macro-instructions depend on its value
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*/
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es = (struct ext4_super_block *) (bh->b_data + offset);
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sbi->s_es = es;
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sb->s_magic = le16_to_cpu(es->s_magic);
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if (sb->s_magic != EXT4_SUPER_MAGIC) {
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if (!silent)
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ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
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goto failed_mount;
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}
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es = sbi->s_es;
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blocksize = sb->s_blocksize;
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sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
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err = ext4_init_metadata_csum(sb, es);
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@ -5005,23 +5083,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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*/
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sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
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if (le32_to_cpu(es->s_log_block_size) >
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(EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
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ext4_msg(sb, KERN_ERR,
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"Invalid log block size: %u",
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le32_to_cpu(es->s_log_block_size));
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goto failed_mount;
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}
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if (le32_to_cpu(es->s_log_cluster_size) >
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(EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
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ext4_msg(sb, KERN_ERR,
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"Invalid log cluster size: %u",
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le32_to_cpu(es->s_log_cluster_size));
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goto failed_mount;
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}
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blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
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if (blocksize == PAGE_SIZE)
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set_opt(sb, DIOREAD_NOLOCK);
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@ -5088,40 +5149,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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goto failed_mount;
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}
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if (sb->s_blocksize != blocksize) {
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/*
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* bh must be released before kill_bdev(), otherwise
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* it won't be freed and its page also. kill_bdev()
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* is called by sb_set_blocksize().
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*/
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brelse(bh);
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/* Validate the filesystem blocksize */
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if (!sb_set_blocksize(sb, blocksize)) {
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ext4_msg(sb, KERN_ERR, "bad block size %d",
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blocksize);
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bh = NULL;
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goto failed_mount;
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}
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logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
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offset = do_div(logical_sb_block, blocksize);
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bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
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if (IS_ERR(bh)) {
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ext4_msg(sb, KERN_ERR,
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"Can't read superblock on 2nd try");
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ret = PTR_ERR(bh);
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bh = NULL;
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goto failed_mount;
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}
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es = (struct ext4_super_block *)(bh->b_data + offset);
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sbi->s_es = es;
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if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
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ext4_msg(sb, KERN_ERR,
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"Magic mismatch, very weird!");
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goto failed_mount;
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}
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}
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has_huge_files = ext4_has_feature_huge_file(sb);
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sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
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has_huge_files);
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@ -5158,7 +5185,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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sbi->s_itb_per_group = sbi->s_inodes_per_group /
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sbi->s_inodes_per_block;
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sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
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sbi->s_sbh = bh;
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sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
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sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
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sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
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@ -5595,7 +5621,7 @@ failed_mount:
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#endif
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fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
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/* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
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brelse(bh);
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brelse(sbi->s_sbh);
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ext4_blkdev_remove(sbi);
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out_fail:
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sb->s_fs_info = NULL;
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