erofs: avoid hardcoded blocksize for subpage block support

As the first step of converting hardcoded blocksize to that specified in
on-disk superblock, convert all call sites of hardcoded blocksize to
sb->s_blocksize except for:

1) use sbi->blkszbits instead of sb->s_blocksize in
erofs_superblock_csum_verify() since sb->s_blocksize has not been
updated with the on-disk blocksize yet when the function is called.

2) use inode->i_blkbits instead of sb->s_blocksize in erofs_bread(),
since the inode operated on may be an anonymous inode in fscache mode.
Currently the anonymous inode is allocated from an anonymous mount
maintained in erofs, while in the near future we may allocate anonymous
inodes from a generic API directly and thus have no access to the
anonymous inode's i_sb.  Thus we keep the block size in i_blkbits for
anonymous inodes in fscache mode.

Be noted that this patch only gets rid of the hardcoded blocksize, in
preparation for actually setting the on-disk block size in the following
patch.  The hard limit of constraining the block size to PAGE_SIZE still
exists until the next patch.

Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230313135309.75269-2-jefflexu@linux.alibaba.com
[ Gao Xiang: fold a patch to fix incorrect truncated offsets. ]
Link: https://lore.kernel.org/r/20230413035734.15457-1-zhujia.zj@bytedance.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 4be7dda3cd24..3502daee8d3b 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -23,8 +23,8 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 	unsigned int ifmt;
 	int err;
 
-	blkaddr = erofs_blknr(inode_loc);
-	*ofs = erofs_blkoff(inode_loc);
+	blkaddr = erofs_blknr(sb, inode_loc);
+	*ofs = erofs_blkoff(sb, inode_loc);
 
 	erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
 		  __func__, vi->nid, *ofs, blkaddr);
@@ -58,11 +58,11 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 	case EROFS_INODE_LAYOUT_EXTENDED:
 		vi->inode_isize = sizeof(struct erofs_inode_extended);
 		/* check if the extended inode acrosses block boundary */
-		if (*ofs + vi->inode_isize <= EROFS_BLKSIZ) {
+		if (*ofs + vi->inode_isize <= sb->s_blocksize) {
 			*ofs += vi->inode_isize;
 			die = (struct erofs_inode_extended *)dic;
 		} else {
-			const unsigned int gotten = EROFS_BLKSIZ - *ofs;
+			const unsigned int gotten = sb->s_blocksize - *ofs;
 
 			copied = kmalloc(vi->inode_isize, GFP_NOFS);
 			if (!copied) {
@@ -176,7 +176,7 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 			err = -EOPNOTSUPP;
 			goto err_out;
 		}
-		vi->chunkbits = LOG_BLOCK_SIZE +
+		vi->chunkbits = sb->s_blocksize_bits +
 			(vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
 	}
 	inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
@@ -188,11 +188,12 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 	if (test_opt(&sbi->opt, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
 	    vi->datalayout == EROFS_INODE_FLAT_PLAIN)
 		inode->i_flags |= S_DAX;
+
 	if (!nblks)
 		/* measure inode.i_blocks as generic filesystems */
-		inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
+		inode->i_blocks = round_up(inode->i_size, sb->s_blocksize) >> 9;
 	else
-		inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
+		inode->i_blocks = nblks << (sb->s_blocksize_bits - 9);
 	return kaddr;
 
 bogusimode:
@@ -210,11 +211,12 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr,
 			      unsigned int m_pofs)
 {
 	struct erofs_inode *vi = EROFS_I(inode);
+	unsigned int bsz = i_blocksize(inode);
 	char *lnk;
 
 	/* if it cannot be handled with fast symlink scheme */
 	if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
-	    inode->i_size >= EROFS_BLKSIZ || inode->i_size < 0) {
+	    inode->i_size >= bsz || inode->i_size < 0) {
 		inode->i_op = &erofs_symlink_iops;
 		return 0;
 	}
@@ -225,7 +227,7 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr,
 
 	m_pofs += vi->xattr_isize;
 	/* inline symlink data shouldn't cross block boundary */
-	if (m_pofs + inode->i_size > EROFS_BLKSIZ) {
+	if (m_pofs + inode->i_size > bsz) {
 		kfree(lnk);
 		erofs_err(inode->i_sb,
 			  "inline data cross block boundary @ nid %llu",