From cc6111a28721e80f741d0ed05c1d6badddb1bcee Mon Sep 17 00:00:00 2001 From: sunshijie Date: Mon, 21 Aug 2023 20:55:20 +0800 Subject: [PATCH] UPSTREAM: erofs: fix compact 4B support for 16k block size 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: Gao Xiang (cherry picked from commit 001b8ccd0650727e54ec16ef72bf1b8eeab7168e https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev) Bug: 296824280 Change-Id: I97918294a1d00a65223e741c3d153f375ab50507 Signed-off-by: sunshijie Signed-off-by: sunshijie --- 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 bb91cc649972..3adab0d9cbe0 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -273,7 +273,7 @@ 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; @@ -375,7 +375,6 @@ 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 = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) + vi->inode_isize + vi->xattr_isize, 8) + sizeof(struct z_erofs_map_header); @@ -384,9 +383,6 @@ 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;