Source kernel commit: 7cef3c8341940febf75db6c25199cd83fb74d52f !lz4_0padding is simply an ancient layout which is mainly used for Linux kernels < 5.3 (prior to the initial EROFS formal version) and generated with the option `-Elegacy-compress` by mkfs.erofs between 1.0 and 1.8.x.
So recently Linux 7.0+ kernels simply use lz4_0padding as another indicator of whether it's an (LZ4) compressed filesystem. Follow the new behavior for erofs-utils too to fix an incremental data build issue [1]. Reported-by: Jonathan Calmels <[email protected]> [1] https://lore.kernel.org/r/[email protected] Signed-off-by: Gao Xiang <[email protected]> --- Hi Jonathan, Could you confirm if this issue works for you? Thanks, Gao Xiang lib/decompress.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/lib/decompress.c b/lib/decompress.c index d23135e0cd43..e6d14f4cbd94 100644 --- a/lib/decompress.c +++ b/lib/decompress.c @@ -466,17 +466,12 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq) char *dest = rq->out; char *src = rq->in; char *buff = NULL; - bool support_0padding = false; unsigned int inputmargin = 0; struct erofs_sb_info *sbi = rq->sbi; - if (erofs_sb_has_lz4_0padding(sbi)) { - support_0padding = true; - - inputmargin = z_erofs_fixup_insize((u8 *)src, rq->inputsize); - if (inputmargin >= rq->inputsize) - return -EFSCORRUPTED; - } + inputmargin = z_erofs_fixup_insize((u8 *)src, rq->inputsize); + if (inputmargin >= rq->inputsize) + return -EFSCORRUPTED; if (rq->decodedskip) { buff = malloc(rq->decodedlength); @@ -485,7 +480,7 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq) dest = buff; } - if (rq->partial_decoding || !support_0padding) + if (rq->partial_decoding) ret = LZ4_decompress_safe_partial(src + inputmargin, dest, rq->inputsize - inputmargin, rq->decodedlength, rq->decodedlength); @@ -589,7 +584,10 @@ static int z_erofs_load_lz4_config(struct erofs_sb_info *sbi, sbi->lz4.max_pclusterblks = 1; /* reserved case */ } else { distance = le16_to_cpu(dsb->u1.lz4_max_distance); + if (!distance && !erofs_sb_has_lz4_0padding(sbi)) + return 0; sbi->lz4.max_pclusterblks = 1; + sbi->available_compr_algs = 1 << Z_EROFS_COMPRESSION_LZ4; } sbi->lz4.max_distance = distance; return 0; @@ -601,10 +599,8 @@ int z_erofs_parse_cfgs(struct erofs_sb_info *sbi, struct erofs_super_block *dsb) erofs_off_t offset; int size, ret = 0; - if (!erofs_sb_has_compr_cfgs(sbi)) { - sbi->available_compr_algs = 1 << Z_EROFS_COMPRESSION_LZ4; + if (!erofs_sb_has_compr_cfgs(sbi)) return z_erofs_load_lz4_config(sbi, dsb, NULL, 0); - } sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs); if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) { -- 2.43.5
