[RFC PATCH 1/2] erofs-utils: support tail-packing inline compressed data
Gao Xiang
hsiangkao at linux.alibaba.com
Tue Oct 26 23:00:37 AEDT 2021
Hi Yue,
On Mon, Oct 25, 2021 at 08:30:43PM +0800, Yue Hu wrote:
> Currently, we only support tail-end inline data for uncompressed
> files, let's support it as well for compressed files.
>
> The idea is from Xiang.
>
> Signed-off-by: Yue Hu <huyue2 at yulong.com>
The patch roughly looks good to me. I'll play with it this week later.
Some comments inline:
> ---
> include/erofs/internal.h | 2 ++
> include/erofs_fs.h | 6 +++-
> lib/compress.c | 74 ++++++++++++++++++++++++++++++++--------
> lib/compressor.c | 9 ++---
> lib/decompress.c | 4 +++
> lib/inode.c | 50 +++++++++++++++------------
> mkfs/main.c | 6 ++++
> 7 files changed, 109 insertions(+), 42 deletions(-)
>
> diff --git a/include/erofs/internal.h b/include/erofs/internal.h
> index da7be56..42ae1ed 100644
> --- a/include/erofs/internal.h
> +++ b/include/erofs/internal.h
> @@ -109,6 +109,7 @@ static inline void erofs_sb_clear_##name(void) \
> EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
> EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
> EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
> +EROFS_FEATURE_FUNCS(tailpacking, incompat, INCOMPAT_TAILPACKING)
> EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
>
> #define EROFS_I_EA_INITED (1 << 0)
> @@ -148,6 +149,7 @@ struct erofs_inode {
> unsigned char inode_isize;
> /* inline tail-end packing size */
> unsigned short idata_size;
> + bool idata_raw;
>
> unsigned int xattr_isize;
> unsigned int extent_isize;
> diff --git a/include/erofs_fs.h b/include/erofs_fs.h
> index 18fc182..7700b27 100644
> --- a/include/erofs_fs.h
> +++ b/include/erofs_fs.h
> @@ -22,10 +22,12 @@
> #define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001
> #define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002
> #define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER 0x00000002
> +#define EROFS_FEATURE_INCOMPAT_TAILPACKING 0x00000004
> #define EROFS_ALL_FEATURE_INCOMPAT \
> (EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \
> EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
> - EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER)
> + EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \
> + EROFS_FEATURE_INCOMPAT_TAILPACKING)
>
> #define EROFS_SB_EXTSLOT_SIZE 16
>
> @@ -230,10 +232,12 @@ struct z_erofs_lz4_cfgs {
> * (4B) + 2B + (4B) if compacted 2B is on.
> * bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
> * bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
> + * bit 3 : inline (un)compressed data
> */
> #define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
> #define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
> #define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
> +#define Z_EROFS_ADVISE_TAILPACKING 0x0008
>
> struct z_erofs_map_header {
> __le32 h_reserved1;
> diff --git a/lib/compress.c b/lib/compress.c
> index 2093bfd..c19f554 100644
> --- a/lib/compress.c
> +++ b/lib/compress.c
> @@ -159,6 +159,18 @@ static unsigned int z_erofs_get_max_pclusterblks(struct erofs_inode *inode)
> return cfg.c_physical_clusterblks;
> }
>
> +static int z_erofs_fill_inline_data(struct erofs_inode *inode, char *data,
> + unsigned int len, bool raw)
> +{
> + inode->idata_raw = raw;
> + inode->idata_size = len;
> + inode->idata = malloc(inode->idata_size);
> + if (!inode->idata)
> + return -ENOMEM;
> + memcpy(inode->idata, data, inode->idata_size);
> + return 0;
> +}
> +
> static int vle_compress_one(struct erofs_inode *inode,
> struct z_erofs_vle_compress_ctx *ctx,
> bool final)
> @@ -169,15 +181,19 @@ static int vle_compress_one(struct erofs_inode *inode,
> int ret;
> static char dstbuf[EROFS_CONFIG_COMPR_MAX_SZ + EROFS_BLKSIZ];
> char *const dst = dstbuf + EROFS_BLKSIZ;
> + bool tail_pcluster = false;
>
> while (len) {
> - const unsigned int pclustersize =
> + unsigned int pclustersize =
> z_erofs_get_max_pclusterblks(inode) * EROFS_BLKSIZ;
> bool raw;
>
> - if (len <= pclustersize) {
> + if (!tail_pcluster && len <= pclustersize) {
> if (final) {
> - if (len <= EROFS_BLKSIZ)
> + if (erofs_sb_has_tailpacking()) {
> + tail_pcluster = true;
> + pclustersize = EROFS_BLKSIZ;
Not quite sure if such condition can be trigged for many times...
Think about it. If the original pclustersize == 16 * EROFS_BLKSIZ, so we
could have at least 16 new pclustersize == EROFS_BLKSIZ then?
But only the last pclustersize == EROFS_BLKSIZ can be inlined...
> + } else if (len <= EROFS_BLKSIZ)
> goto nocompression;
> } else {
> break;
> @@ -194,6 +210,17 @@ static int vle_compress_one(struct erofs_inode *inode,
> inode->i_srcpath,
> erofs_strerror(ret));
> }
> + if (tail_pcluster && len < EROFS_BLKSIZ) {
> + ret = z_erofs_fill_inline_data(inode,
> + (char *)(ctx->queue + ctx->head), len,
> + true);
> + if (ret)
> + return ret;
> + count = len;
> + raw = true;
> + ctx->compressedblks = 1;
> + goto add_head;
> + }
> nocompression:
> ret = write_uncompressed_extent(ctx, &len, dst);
> if (ret < 0)
> @@ -202,6 +229,16 @@ nocompression:
> ctx->compressedblks = 1;
> raw = true;
> } else {
> + if (tail_pcluster && ret < EROFS_BLKSIZ &&
> + !(len - count)) {
> + ret = z_erofs_fill_inline_data(inode, dst, ret,
> + false);
> + if (ret)
> + return ret;
> + raw = false;
> + ctx->compressedblks = 1;
> + goto add_head;
> + }
> const unsigned int tailused = ret & (EROFS_BLKSIZ - 1);
> const unsigned int padding =
> erofs_sb_has_lz4_0padding() && tailused ?
> @@ -226,11 +263,13 @@ nocompression:
> raw = false;
> }
>
> +add_head:
> ctx->head += count;
> /* write compression indexes for this pcluster */
> vle_write_indexes(ctx, count, raw);
>
> - ctx->blkaddr += ctx->compressedblks;
> + if (!inode->idata_size)
> + ctx->blkaddr += ctx->compressedblks;
> len -= count;
>
> if (!final && ctx->head >= EROFS_CONFIG_COMPR_MAX_SZ) {
> @@ -475,7 +514,7 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
> fd = open(inode->i_srcpath, O_RDONLY | O_BINARY);
> if (fd < 0) {
> ret = -errno;
> - goto err_free;
> + goto err_free_meta;
> }
>
> /* allocate main data buffer */
> @@ -530,16 +569,19 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
> goto err_bdrop;
> }
>
> + inode->idata_size = 0;
> +
> /* do the final round */
> ret = vle_compress_one(inode, &ctx, true);
> if (ret)
> - goto err_bdrop;
> + goto err_free_id;
>
> /* fall back to no compression mode */
> compressed_blocks = ctx.blkaddr - blkaddr;
> - if (compressed_blocks >= BLK_ROUND_UP(inode->i_size)) {
> + if (compressed_blocks >= BLK_ROUND_UP(inode->i_size) -
> + (inode->idata_size ? 1 : 0) ) {
> ret = -ENOSPC;
> - goto err_bdrop;
> + goto err_free_id;
> }
>
> vle_write_indexes_final(&ctx);
> @@ -553,12 +595,11 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
> inode->i_srcpath, (unsigned long long)inode->i_size,
> compressed_blocks);
>
> - /*
> - * TODO: need to move erofs_bdrop to erofs_write_tail_end
> - * when both mkfs & kernel support compression inline.
> - */
> - erofs_bdrop(bh, false);
> - inode->idata_size = 0;
> + if (inode->idata_size)
> + inode->bh_data = bh;
> + else
> + erofs_bdrop(bh, false);
> +
> inode->u.i_blocks = compressed_blocks;
>
> legacymetasize = ctx.metacur - compressmeta;
> @@ -573,11 +614,14 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
> inode->compressmeta = compressmeta;
> return 0;
>
> +err_free_id:
> + if (inode->idata)
> + free(inode->idata);
> err_bdrop:
> erofs_bdrop(bh, true); /* revoke buffer */
> err_close:
> close(fd);
> -err_free:
> +err_free_meta:
> free(compressmeta);
> return ret;
> }
> diff --git a/lib/compressor.c b/lib/compressor.c
> index 8836e0c..26189b6 100644
> --- a/lib/compressor.c
> +++ b/lib/compressor.c
> @@ -28,7 +28,7 @@ int erofs_compress_destsize(struct erofs_compress *c,
> void *dst,
> unsigned int dstsize)
> {
> - unsigned uncompressed_size;
> + unsigned compressed_size;
> int ret;
>
> DBG_BUGON(!c->alg);
> @@ -41,9 +41,10 @@ int erofs_compress_destsize(struct erofs_compress *c,
> return ret;
>
> /* check if there is enough gains to compress */
> - uncompressed_size = *srcsize;
> - if (roundup(ret, EROFS_BLKSIZ) >= uncompressed_size *
> - c->compress_threshold / 100)
> + compressed_size = *srcsize <= EROFS_BLKSIZ ? ret :
> + roundup(ret, EROFS_BLKSIZ);
> +
> + if (*srcsize <= compressed_size * c->compress_threshold / 100)
> return -EAGAIN;
> return ret;
> }
> diff --git a/lib/decompress.c b/lib/decompress.c
> index 490c4bc..0b6678d 100644
> --- a/lib/decompress.c
> +++ b/lib/decompress.c
> @@ -9,6 +9,7 @@
>
> #include "erofs/decompress.h"
> #include "erofs/err.h"
> +#include "erofs/print.h"
>
> #ifdef LZ4_ENABLED
> #include <lz4.h>
> @@ -50,6 +51,9 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
> rq->decodedlength);
>
> if (ret != (int)rq->decodedlength) {
> + erofs_err("failed to %s decompress %d in[%u, %u] out[%u]",
> + rq->partial_decoding ? "partial" : "full",
> + ret, rq->inputsize, inputmargin, rq->decodedlength);
> ret = -EIO;
> goto out;
> }
> diff --git a/lib/inode.c b/lib/inode.c
> index 787e5b4..1c08608 100644
> --- a/lib/inode.c
> +++ b/lib/inode.c
> @@ -521,9 +521,6 @@ int erofs_prepare_tail_block(struct erofs_inode *inode)
> struct erofs_buffer_head *bh;
> int ret;
>
> - if (!inode->idata_size)
> - return 0;
> -
> bh = inode->bh_data;
> if (!bh) {
> bh = erofs_balloc(DATA, EROFS_BLKSIZ, 0, 0);
> @@ -557,26 +554,21 @@ int erofs_prepare_inode_buffer(struct erofs_inode *inode)
> inodesize = Z_EROFS_VLE_EXTENT_ALIGN(inodesize) +
> inode->extent_isize;
>
> - if (is_inode_layout_compression(inode))
> - goto noinline;
> -
> - /*
> - * if the file size is block-aligned for uncompressed files,
> - * should use EROFS_INODE_FLAT_PLAIN data mapping mode.
> - */
> if (!inode->idata_size)
> - inode->datalayout = EROFS_INODE_FLAT_PLAIN;
> + goto noinline;
>
> bh = erofs_balloc(INODE, inodesize, 0, inode->idata_size);
> if (bh == ERR_PTR(-ENOSPC)) {
> int ret;
>
> - inode->datalayout = EROFS_INODE_FLAT_PLAIN;
> -noinline:
> /* expend an extra block for tail-end data */
> ret = erofs_prepare_tail_block(inode);
> if (ret)
> return ret;
> +noinline:
> + if (!is_inode_layout_compression(inode))
> + inode->datalayout = EROFS_INODE_FLAT_PLAIN;
> +
> bh = erofs_balloc(INODE, inodesize, 0, 0);
> if (IS_ERR(bh))
> return PTR_ERR(bh);
> @@ -584,7 +576,16 @@ noinline:
> } else if (IS_ERR(bh)) {
> return PTR_ERR(bh);
> } else if (inode->idata_size) {
> - inode->datalayout = EROFS_INODE_FLAT_INLINE;
> + if (is_inode_layout_compression(inode)) {
> + struct z_erofs_map_header *h = inode->compressmeta;
> + h->h_advise |= Z_EROFS_ADVISE_TAILPACKING;
> + erofs_dbg("%s: inline %scompressed data (%u bytes)",
> + inode->i_srcpath,
> + inode->idata_raw ? "un" : "",
> + inode->idata_size);
> + } else {
> + inode->datalayout = EROFS_INODE_FLAT_INLINE;
> + }
>
> /* allocate inline buffer */
> ibh = erofs_battach(bh, META, inode->idata_size);
> @@ -640,20 +641,25 @@ int erofs_write_tail_end(struct erofs_inode *inode)
> ibh->op = &erofs_write_inline_bhops;
> } else {
> int ret;
> - erofs_off_t pos;
> + erofs_off_t pos, pos0;
> + const unsigned short padding = EROFS_BLKSIZ - inode->idata_size;
>
> erofs_mapbh(bh->block);
> pos = erofs_btell(bh, true) - EROFS_BLKSIZ;
> + pos0 = pos + inode->idata_size;
> +
> + if (is_inode_layout_compression(inode) &&
> + erofs_sb_has_lz4_0padding() && !inode->idata_raw) {
> + pos0 = pos;
> + pos += padding;
> + }
I'd suggest don't use 0padding but record compressed_sized for
tail-packing pcluster in the map header.... (need 2 bytes to record)
Thanks,
Gao Xiang
> ret = dev_write(inode->idata, pos, inode->idata_size);
> if (ret)
> return ret;
> - if (inode->idata_size < EROFS_BLKSIZ) {
> - ret = dev_fillzero(pos + inode->idata_size,
> - EROFS_BLKSIZ - inode->idata_size,
> - false);
> - if (ret)
> - return ret;
> - }
> + ret = dev_fillzero(pos0, padding, false);
> + if (ret)
> + return ret;
> +
> inode->idata_size = 0;
> free(inode->idata);
> inode->idata = NULL;
> diff --git a/mkfs/main.c b/mkfs/main.c
> index e476189..7dd29df 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -48,6 +48,7 @@ static struct option long_options[] = {
> {"product-out", required_argument, NULL, 11},
> {"fs-config-file", required_argument, NULL, 12},
> #endif
> + {"inline", no_argument, NULL, 13},
> {0, 0, 0, 0},
> };
>
> @@ -87,6 +88,7 @@ static void usage(void)
> " --all-root make all files owned by root\n"
> " --help display this help and exit\n"
> " --max-extent-bytes=# set maximum decompressed extent size # in bytes\n"
> + " --inline tail-packing inline compressed data\n"
> #ifndef NDEBUG
> " --random-pclusterblks randomize pclusterblks for big pcluster (debugging only)\n"
> #endif
> @@ -304,6 +306,10 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
> }
> cfg.c_physical_clusterblks = i / EROFS_BLKSIZ;
> break;
> + case 13:
> + erofs_sb_set_tailpacking();
> + erofs_warn("EXPERIMENTAL compression inline feature in use. Use at your own risk!");
> + break;
>
> case 1:
> usage();
> --
> 2.29.0
>
>
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