From: Gao Xiang hsiangkao@linux.alibaba.com
[ Upstream commit 8f9530aeeb4f756bdfa70510b40e5d28ea3c742e ]
- Set `compressedblks = 1` directly for non-bigpcluster cases. This simplifies the logic a bit since lcluster sizes larger than one block are unsupported and the details remain unclear.
- For Z_EROFS_LCLUSTER_TYPE_PLAIN pclusters, avoid assuming `compressedblks = 1` by default. Instead, check if Z_EROFS_ADVISE_BIG_PCLUSTER_2 is set.
It basically has no impact to existing valid images, but it's useful to find the gap to prepare for large PLAIN pclusters.
Link: https://lore.kernel.org/r/20250123090109.973463-1-hsiangkao@linux.alibaba.co... Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Stable-dep-of: b44686c8391b ("erofs: fix large fragment handling") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/erofs/zmap.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index b9e35089c9b8d..689437e99a5a3 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -294,27 +294,23 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, unsigned int initial_lcn) { - struct super_block *sb = m->inode->i_sb; - struct erofs_inode *const vi = EROFS_I(m->inode); - struct erofs_map_blocks *const map = m->map; - const unsigned int lclusterbits = vi->z_logical_clusterbits; - unsigned long lcn; + struct inode *inode = m->inode; + struct super_block *sb = inode->i_sb; + struct erofs_inode *vi = EROFS_I(inode); + bool bigpcl1 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; + bool bigpcl2 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2; + unsigned long lcn = m->lcn + 1; int err;
- DBG_BUGON(m->type != Z_EROFS_LCLUSTER_TYPE_PLAIN && - m->type != Z_EROFS_LCLUSTER_TYPE_HEAD1 && - m->type != Z_EROFS_LCLUSTER_TYPE_HEAD2); + DBG_BUGON(m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD); DBG_BUGON(m->type != m->headtype);
- if (m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN || - ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1) && - !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) || - ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && - !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2))) { - map->m_plen = 1ULL << lclusterbits; - return 0; - } - lcn = m->lcn + 1; + if ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1 && !bigpcl1) || + ((m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN || + m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && !bigpcl2) || + (lcn << vi->z_logical_clusterbits) >= inode->i_size) + m->compressedblks = 1; + if (m->compressedblks) goto out;
@@ -339,9 +335,9 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, case Z_EROFS_LCLUSTER_TYPE_HEAD2: /* * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type - * rather than CBLKCNT, it's a 1 lcluster-sized pcluster. + * rather than CBLKCNT, it's a 1 block-sized pcluster. */ - m->compressedblks = 1 << (lclusterbits - sb->s_blocksize_bits); + m->compressedblks = 1; break; case Z_EROFS_LCLUSTER_TYPE_NONHEAD: if (m->delta[0] != 1) @@ -356,7 +352,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, return -EFSCORRUPTED; } out: - map->m_plen = erofs_pos(sb, m->compressedblks); + m->map->m_plen = erofs_pos(sb, m->compressedblks); return 0; err_bonus_cblkcnt: erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);