Source kernel commit: 2a810ea79cd7a6d5f134ea69ca2ba726e600cbc4
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
lib/zmap.c | 112 ++++++++++++++++++++++-------------------------------
1 file changed, 47 insertions(+), 65 deletions(-)
diff --git a/lib/zmap.c b/lib/zmap.c
index c48eba4..b2aa483 100644
--- a/lib/zmap.c
+++ b/lib/zmap.c
@@ -109,17 +109,49 @@ static int get_compacted_la_distance(unsigned int lobits,
return d1;
}
-static int unpack_compacted_index(struct z_erofs_maprecorder *m,
- unsigned int amortizedshift,
- erofs_off_t pos, bool lookahead)
+static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
+ unsigned long lcn, bool lookahead)
{
struct erofs_inode *const vi = m->inode;
+ struct erofs_sb_info *sbi = vi->sbi;
+ const erofs_off_t ebase = sizeof(struct z_erofs_map_header) +
+ round_up(erofs_iloc(vi) + vi->inode_isize + vi->xattr_isize, 8);
const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ const unsigned int totalidx = BLK_ROUND_UP(sbi, vi->i_size);
+ unsigned int compacted_4b_initial, compacted_2b, amortizedshift;
unsigned int vcnt, base, lo, lobits, encodebits, nblk, eofs;
- bool big_pcluster;
+ bool big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
+ erofs_blk_t eblk;
+ erofs_off_t pos;
u8 *in, type;
- int i;
+ int i, err;
+
+ if (lcn >= totalidx || lclusterbits > 14)
+ return -EINVAL;
+ m->lcn = lcn;
+ /* used to align to 32-byte (compacted_2b) alignment */
+ compacted_4b_initial = ((32 - ebase % 32) / 4) & 7;
+ compacted_2b = 0;
+ if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
+ compacted_4b_initial < totalidx)
+ compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
+
+ pos = ebase;
+ amortizedshift = 2; /* compact_4b */
+ if (lcn >= compacted_4b_initial) {
+ pos += compacted_4b_initial * 4;
+ lcn -= compacted_4b_initial;
+ if (lcn < compacted_2b) {
+ amortizedshift = 1;
+ } else {
+ pos += compacted_2b * 2;
+ lcn -= compacted_2b;
+ }
+ }
+ pos += lcn * (1 << amortizedshift);
+
+ /* figure out the lcluster count in this pack */
if (1 << amortizedshift == 4 && lclusterbits <= 14)
vcnt = 2;
else if (1 << amortizedshift == 2 && lclusterbits <= 12)
@@ -127,13 +159,20 @@ static int unpack_compacted_index(struct
z_erofs_maprecorder *m,
else
return -EOPNOTSUPP;
+ eblk = erofs_blknr(sbi, pos);
+ if (m->map->index != eblk) {
+ err = erofs_blk_read(sbi, 0, m->kaddr, eblk, 1);
+ if (err < 0)
+ return err;
+ m->map->index = eblk;
+ }
+
/* it doesn't equal to round_up(..) */
m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
(vcnt << amortizedshift);
- big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1;
lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
- eofs = erofs_blkoff(vi->sbi, pos);
+ eofs = erofs_blkoff(sbi, pos);
base = round_down(eofs, vcnt << amortizedshift);
in = m->kaddr + base;
@@ -201,9 +240,9 @@ static int unpack_compacted_index(struct
z_erofs_maprecorder *m,
nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT;
continue;
}
+ /* bigpcluster shouldn't have plain d0 == 1 */
if (lo <= 1) {
DBG_BUGON(1);
- /* --i; ++nblk; continue; */
return -EFSCORRUPTED;
}
i -= lo - 2;
@@ -217,63 +256,6 @@ static int unpack_compacted_index(struct
z_erofs_maprecorder *m,
return 0;
}
-static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
- unsigned long lcn, bool lookahead)
-{
- struct erofs_inode *const vi = m->inode;
- struct erofs_sb_info *sbi = vi->sbi;
- const erofs_off_t ebase = round_up(erofs_iloc(vi) + vi->inode_isize +
- vi->xattr_isize, 8) +
- sizeof(struct z_erofs_map_header);
- const unsigned int totalidx = BLK_ROUND_UP(sbi, vi->i_size);
- unsigned int compacted_4b_initial, compacted_2b;
- unsigned int amortizedshift;
- erofs_off_t pos;
- erofs_blk_t eblk;
- int err;
-
- if (lcn >= totalidx || vi->z_logical_clusterbits > 14)
- return -EINVAL;
-
- m->lcn = lcn;
- /* used to align to 32-byte (compacted_2b) alignment */
- compacted_4b_initial = (32 - ebase % 32) / 4;
- if (compacted_4b_initial == 32 / 4)
- compacted_4b_initial = 0;
-
- if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
- compacted_4b_initial < totalidx)
- compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
- else
- compacted_2b = 0;
-
- pos = ebase;
- if (lcn < compacted_4b_initial) {
- amortizedshift = 2;
- goto out;
- }
- pos += compacted_4b_initial * 4;
- lcn -= compacted_4b_initial;
-
- if (lcn < compacted_2b) {
- amortizedshift = 1;
- goto out;
- }
- pos += compacted_2b * 2;
- lcn -= compacted_2b;
- amortizedshift = 2;
-out:
- pos += lcn * (1 << amortizedshift);
- eblk = erofs_blknr(sbi, pos);
- if (m->map->index != eblk) {
- err = erofs_blk_read(sbi, 0, m->kaddr, eblk, 1);
- if (err < 0)
- return err;
- m->map->index = eblk;
- }
- return unpack_compacted_index(m, amortizedshift, pos, lookahead);
-}
-
static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m,
unsigned int lcn, bool lookahead)
{
--
2.43.5
