> On Sep 15, 2020, at 11:31 PM, Chao Yu <yuch...@huawei.com> wrote: > > Hi Nick, > > remove not related mailing list. > > On 2020/9/16 11:43, Nick Terrell wrote: >> From: Nick Terrell <terre...@fb.com> >> Move away from the compatibility wrapper to the zstd-1.4.6 API. This >> code is more efficient because it uses the single-pass API instead of >> the streaming API. The streaming API is not necessary because the whole >> input and output buffers are available. This saves memory because we >> don't need to allocate a buffer for the window. It is also more >> efficient because it saves unnecessary memcpy calls. >> I've had problems testing this code because I see data truncation before >> and after this patchset. Help testing this patch would be much >> appreciated. > > Can you please explain more about data truncation? I'm a little confused... > > Do you mean that f2fs doesn't allocate enough memory for zstd compression, > so that compression is not finished actually, the compressed data is truncated > at dst buffer?
Hi Chao, I’ve tested F2FS using a benchmark I adapted from testing BtrFS [0]. It is possible that the script I’m using is buggy or is exposing an edge case in F2FS. The files that I copy to F2FS and compress end up truncated with a hole at the end. It is based off of upstream commit ab29a807a7. E.g. the end of the copied file looks like this, but the original file has non-zero data In the end. Until the hole at the end the file is correct. od dickens | tail -n 5 > 46667760 067502 066167 020056 040440 020163 023511 006555 060412 > 46670000 000000 000000 000000 000000 000000 000000 000000 000000 > * > 46703060 000000 000000 000000 000000 000000 000000 000000 > 46703076 [0] https://gist.github.com/terrelln/7dd2919937dfbdb8e839e4ad11c81db4 Best, Nick > Thanks, > >> Signed-off-by: Nick Terrell <terre...@fb.com> >> --- >> fs/f2fs/compress.c | 102 +++++++++++++++++---------------------------- >> 1 file changed, 38 insertions(+), 64 deletions(-) >> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c >> index e056f3a2b404..b79efce81651 100644 >> --- a/fs/f2fs/compress.c >> +++ b/fs/f2fs/compress.c >> @@ -11,7 +11,8 @@ >> #include <linux/backing-dev.h> >> #include <linux/lzo.h> >> #include <linux/lz4.h> >> -#include <linux/zstd_compat.h> >> +#include <linux/zstd.h> >> +#include <linux/zstd_errors.h> >> #include "f2fs.h" >> #include "node.h" >> @@ -298,21 +299,21 @@ static const struct f2fs_compress_ops f2fs_lz4_ops = { >> static int zstd_init_compress_ctx(struct compress_ctx *cc) >> { >> ZSTD_parameters params; >> - ZSTD_CStream *stream; >> + ZSTD_CCtx *ctx; >> void *workspace; >> unsigned int workspace_size; >> params = ZSTD_getParams(F2FS_ZSTD_DEFAULT_CLEVEL, cc->rlen, 0); >> - workspace_size = ZSTD_CStreamWorkspaceBound(params.cParams); >> + workspace_size = ZSTD_estimateCCtxSize_usingCParams(params.cParams); >> workspace = f2fs_kvmalloc(F2FS_I_SB(cc->inode), >> workspace_size, GFP_NOFS); >> if (!workspace) >> return -ENOMEM; >> - stream = ZSTD_initCStream(params, 0, workspace, workspace_size); >> - if (!stream) { >> - printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_initCStream >> failed\n", >> + ctx = ZSTD_initStaticCCtx(workspace, workspace_size); >> + if (!ctx) { >> + printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_inittaticCStream >> failed\n", >> KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, >> __func__); >> kvfree(workspace); >> @@ -320,7 +321,7 @@ static int zstd_init_compress_ctx(struct compress_ctx >> *cc) >> } >> cc->private = workspace; >> - cc->private2 = stream; >> + cc->private2 = ctx; >> cc->clen = cc->rlen - PAGE_SIZE - COMPRESS_HEADER_SIZE; >> return 0; >> @@ -335,65 +336,48 @@ static void zstd_destroy_compress_ctx(struct >> compress_ctx *cc) >> static int zstd_compress_pages(struct compress_ctx *cc) >> { >> - ZSTD_CStream *stream = cc->private2; >> - ZSTD_inBuffer inbuf; >> - ZSTD_outBuffer outbuf; >> - int src_size = cc->rlen; >> - int dst_size = src_size - PAGE_SIZE - COMPRESS_HEADER_SIZE; >> - int ret; >> - >> - inbuf.pos = 0; >> - inbuf.src = cc->rbuf; >> - inbuf.size = src_size; >> - >> - outbuf.pos = 0; >> - outbuf.dst = cc->cbuf->cdata; >> - outbuf.size = dst_size; >> - >> - ret = ZSTD_compressStream(stream, &outbuf, &inbuf); >> - if (ZSTD_isError(ret)) { >> - printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_compressStream >> failed, ret: %d\n", >> - KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, >> - __func__, ZSTD_getErrorCode(ret)); >> - return -EIO; >> - } >> - >> - ret = ZSTD_endStream(stream, &outbuf); >> + ZSTD_CCtx *ctx = cc->private2; >> + const size_t src_size = cc->rlen; >> + const size_t dst_size = src_size - PAGE_SIZE - COMPRESS_HEADER_SIZE; >> + ZSTD_parameters params = ZSTD_getParams(F2FS_ZSTD_DEFAULT_CLEVEL, >> src_size, 0); >> + size_t ret; >> + >> + ret = ZSTD_compress_advanced( >> + ctx, cc->cbuf->cdata, dst_size, cc->rbuf, src_size, >> NULL, 0, params); >> if (ZSTD_isError(ret)) { >> - printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_endStream returned >> %d\n", >> + /* >> + * there is compressed data remained in intermediate buffer due >> to >> + * no more space in cbuf.cdata >> + */ >> + if (ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall) >> + return -EAGAIN; >> + /* other compression errors return -EIO */ >> + printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_compress_advanced >> failed, err: %s\n", >> KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, >> - __func__, ZSTD_getErrorCode(ret)); >> + __func__, ZSTD_getErrorName(ret)); >> return -EIO; >> } >> - /* >> - * there is compressed data remained in intermediate buffer due to >> - * no more space in cbuf.cdata >> - */ >> - if (ret) >> - return -EAGAIN; >> - >> - cc->clen = outbuf.pos; >> + cc->clen = ret; >> return 0; >> } >> static int zstd_init_decompress_ctx(struct decompress_io_ctx *dic) >> { >> - ZSTD_DStream *stream; >> + ZSTD_DCtx *ctx; >> void *workspace; >> unsigned int workspace_size; >> - workspace_size = ZSTD_DStreamWorkspaceBound(MAX_COMPRESS_WINDOW_SIZE); >> + workspace_size = ZSTD_estimateDCtxSize(); >> workspace = f2fs_kvmalloc(F2FS_I_SB(dic->inode), >> workspace_size, GFP_NOFS); >> if (!workspace) >> return -ENOMEM; >> - stream = ZSTD_initDStream(MAX_COMPRESS_WINDOW_SIZE, >> - workspace, workspace_size); >> - if (!stream) { >> - printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_initDStream >> failed\n", >> + ctx = ZSTD_initStaticDCtx(workspace, workspace_size); >> + if (!ctx) { >> + printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_initStaticDCtx >> failed\n", >> KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, >> __func__); >> kvfree(workspace); >> @@ -401,7 +385,7 @@ static int zstd_init_decompress_ctx(struct >> decompress_io_ctx *dic) >> } >> dic->private = workspace; >> - dic->private2 = stream; >> + dic->private2 = ctx; >> return 0; >> } >> @@ -415,28 +399,18 @@ static void zstd_destroy_decompress_ctx(struct >> decompress_io_ctx *dic) >> static int zstd_decompress_pages(struct decompress_io_ctx *dic) >> { >> - ZSTD_DStream *stream = dic->private2; >> - ZSTD_inBuffer inbuf; >> - ZSTD_outBuffer outbuf; >> - int ret; >> - >> - inbuf.pos = 0; >> - inbuf.src = dic->cbuf->cdata; >> - inbuf.size = dic->clen; >> - >> - outbuf.pos = 0; >> - outbuf.dst = dic->rbuf; >> - outbuf.size = dic->rlen; >> + ZSTD_DCtx *ctx = dic->private2; >> + size_t ret; >> - ret = ZSTD_decompressStream(stream, &outbuf, &inbuf); >> + ret = ZSTD_decompressDCtx(ctx, dic->rbuf, dic->rlen, dic->cbuf->cdata, >> dic->clen); >> if (ZSTD_isError(ret)) { >> - printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_compressStream >> failed, ret: %d\n", >> + printk_ratelimited("%sF2FS-fs (%s): %s ZSTD_decompressDCtx >> failed, err: %s\n", >> KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, >> - __func__, ZSTD_getErrorCode(ret)); >> + __func__, ZSTD_getErrorName(ret)); >> return -EIO; >> } >> - if (dic->rlen != outbuf.pos) { >> + if (dic->rlen != ret) { >> printk_ratelimited("%sF2FS-fs (%s): %s ZSTD invalid rlen:%zu, " >> "expected:%lu\n", KERN_ERR, >> F2FS_I_SB(dic->inode)->sb->s_id,
