erofs-utils: mkfs: support compact indexes for smaller block sizes

This commit also adds mkfs support of compact indexes for smaller
block sizes (less than 4096).

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231123052245.868698-2-hsiangkao@linux.alibaba.com

diff --git a/lib/compress.c b/lib/compress.c
index 47f1c1d2c1f0c87b5421de740a7fbee4d7138c51..61328edaf14332d98594b207fdf064f4d59bd17e 100644 (file)
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -627,19 +627,20 @@ static void *write_compacted_indexes(u8 *out,
                                     struct z_erofs_compressindex_vec *cv,
                                     erofs_blk_t *blkaddr_ret,
                                     unsigned int destsize,
-                                    unsigned int logical_clusterbits,
+                                    unsigned int lclusterbits,
                                     bool final, bool *dummy_head,
                                     bool update_blkaddr)
 {
-       unsigned int vcnt, encodebits, pos, i, cblks;
+       unsigned int vcnt, lobits, encodebits, pos, i, cblks;
        erofs_blk_t blkaddr;
 
        if (destsize == 4)
                vcnt = 2;
-       else if (destsize == 2 && logical_clusterbits == 12)
+       else if (destsize == 2 && lclusterbits <= 12)
                vcnt = 16;
        else
                return ERR_PTR(-EINVAL);
+       lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
        encodebits = (vcnt * destsize * 8 - 32) / vcnt;
        blkaddr = *blkaddr_ret;
 
@@ -656,7 +657,7 @@ static void *write_compacted_indexes(u8 *out,
                                *dummy_head = false;
                        } else if (i + 1 == vcnt) {
                                offset = min_t(u16, cv[i].u.delta[1],
-                                               (1 << logical_clusterbits) - 1);
+                                               (1 << lobits) - 1);
                        } else {
                                offset = cv[i].u.delta[0];
                        }
@@ -676,7 +677,7 @@ static void *write_compacted_indexes(u8 *out,
                                DBG_BUGON(cv[i].u.blkaddr);
                        }
                }
-               v = (cv[i].clustertype << logical_clusterbits) | offset;
+               v = (cv[i].clustertype << lobits) | offset;
                rem = pos & 7;
                ch = out[pos / 8] & ((1 << rem) - 1);
                out[pos / 8] = (v << rem) | ch;
@@ -711,7 +712,7 @@ int z_erofs_convert_to_compacted_format(struct erofs_inode *inode,
        bool dummy_head;
        bool big_pcluster = erofs_sb_has_big_pcluster(sbi);
 
-       if (logical_clusterbits < sbi->blkszbits || sbi->blkszbits < 12)
+       if (logical_clusterbits < sbi->blkszbits)
                return -EINVAL;
        if (logical_clusterbits > 14) {
                erofs_err("compact format is unsupported for lcluster size %u",
@@ -720,7 +721,7 @@ int z_erofs_convert_to_compacted_format(struct erofs_inode *inode,
        }
 
        if (inode->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) {
-               if (logical_clusterbits != 12) {
+               if (logical_clusterbits > 12) {
                        erofs_err("compact 2B is unsupported for lcluster size %u",
                                  1 << logical_clusterbits);
                        return -EINVAL;