From 9a534100382a13ac590702b9ae7670a642b33db8 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Thu, 1 Jun 2023 19:23:41 +0800 Subject: [PATCH] erofs: fix compact 4B support for 16k block size [ Upstream commit 001b8ccd0650727e54ec16ef72bf1b8eeab7168e ] In compact 4B, two adjacent lclusters are packed together as a unit to form on-disk indexes for effective random access, as below: (amortized = 4, vcnt = 2) _____________________________________________ |___@_____ encoded bits __________|_ blkaddr _| 0 . amortized * vcnt = 8 . . . . amortized * vcnt - 4 = 4 . . .____________________________. |_type (2 bits)_|_clusterofs_| Therefore, encoded bits for each pack are 32 bits (4 bytes). IOWs, since each lcluster can get 16 bits for its type and clusterofs, the maximum supported lclustersize for compact 4B format is 16k (14 bits). Fix this to enable compact 4B format for 16k lclusters (blocks), which is tested on an arm64 server with 16k page size. Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support") Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20230601112341.56960-1-hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin --- fs/erofs/zmap.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 3961bb5..0337b70 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -271,7 +271,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m, u8 *in, type; bool big_pcluster; - if (1 << amortizedshift == 4) + if (1 << amortizedshift == 4 && lclusterbits <= 14) vcnt = 2; else if (1 << amortizedshift == 2 && lclusterbits == 12) vcnt = 16; @@ -373,7 +373,6 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m, { struct inode *const inode = m->inode; struct erofs_inode *const vi = EROFS_I(inode); - const unsigned int lclusterbits = vi->z_logical_clusterbits; const erofs_off_t ebase = sizeof(struct z_erofs_map_header) + ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); const unsigned int totalidx = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); @@ -381,9 +380,6 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m, unsigned int amortizedshift; erofs_off_t pos; - if (lclusterbits != 12) - return -EOPNOTSUPP; - if (lcn >= totalidx) return -EINVAL; -- 2.7.4