From: Jianan Huang <jnhuang95@gmail.com>
To: u-boot@lists.denx.de
Cc: linux-erofs@lists.ozlabs.org
Subject: [PATCH] fs/erofs: add DEFLATE algorithm support
Date: Sun, 14 Apr 2024 23:04:14 +0800 [thread overview]
Message-ID: <20240414150414.231027-1-jnhuang95@gmail.com> (raw)
This patch adds DEFLATE compression algorithm support. It's a good choice
to trade off between compression ratios and performance compared to LZ4.
Alternatively, DEFLATE could be used for some specific files since EROFS
supports multiple compression algorithms in one image.
Signed-off-by: Jianan Huang <jnhuang95@gmail.com>
---
fs/erofs/Kconfig | 15 ++++++++
fs/erofs/decompress.c | 83 +++++++++++++++++++++++++++++++++++++++++++
fs/erofs/erofs_fs.h | 1 +
3 files changed, 99 insertions(+)
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index ee4e777c5c..c8463357ca 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -19,3 +19,18 @@ config FS_EROFS_ZIP
help
Enable fixed-sized output compression for EROFS.
If you don't want to enable compression feature, say N.
+
+config FS_EROFS_ZIP_DEFLATE
+ bool "EROFS DEFLATE compressed data support"
+ depends on FS_EROFS_ZIP
+ select ZLIB
+ help
+ Saying Y here includes support for reading EROFS file systems
+ containing DEFLATE compressed data. It gives better compression
+ ratios than the default LZ4 format, while it costs more CPU
+ overhead.
+
+ DEFLATE support is an experimental feature for now and so most
+ file systems will be readable without selecting this option.
+
+ If unsure, say N.
diff --git a/fs/erofs/decompress.c b/fs/erofs/decompress.c
index e04e5c34a8..ec74816534 100644
--- a/fs/erofs/decompress.c
+++ b/fs/erofs/decompress.c
@@ -1,6 +1,85 @@
// SPDX-License-Identifier: GPL-2.0+
#include "decompress.h"
+#if IS_ENABLED(CONFIG_ZLIB)
+#include <u-boot/zlib.h>
+
+/* report a zlib or i/o error */
+static int zerr(int ret)
+{
+ switch (ret) {
+ case Z_STREAM_ERROR:
+ return -EINVAL;
+ case Z_DATA_ERROR:
+ return -EIO;
+ case Z_MEM_ERROR:
+ return -ENOMEM;
+ case Z_ERRNO:
+ default:
+ return -EFAULT;
+ }
+}
+
+static int z_erofs_decompress_deflate(struct z_erofs_decompress_req *rq)
+{
+ u8 *dest = (u8 *)rq->out;
+ u8 *src = (u8 *)rq->in;
+ u8 *buff = NULL;
+ unsigned int inputmargin = 0;
+ z_stream strm;
+ int ret;
+
+ while (!src[inputmargin & (erofs_blksiz() - 1)])
+ if (!(++inputmargin & (erofs_blksiz() - 1)))
+ break;
+
+ if (inputmargin >= rq->inputsize)
+ return -EFSCORRUPTED;
+
+ if (rq->decodedskip) {
+ buff = malloc(rq->decodedlength);
+ if (!buff)
+ return -ENOMEM;
+ dest = buff;
+ }
+
+ /* allocate inflate state */
+ strm.zalloc = Z_NULL;
+ strm.zfree = Z_NULL;
+ strm.opaque = Z_NULL;
+ strm.avail_in = 0;
+ strm.next_in = Z_NULL;
+ ret = inflateInit2(&strm, -15);
+ if (ret != Z_OK) {
+ free(buff);
+ return zerr(ret);
+ }
+
+ strm.next_in = src + inputmargin;
+ strm.avail_in = rq->inputsize - inputmargin;
+ strm.next_out = dest;
+ strm.avail_out = rq->decodedlength;
+
+ ret = inflate(&strm, rq->partial_decoding ? Z_SYNC_FLUSH : Z_FINISH);
+ if (ret != Z_STREAM_END || strm.total_out != rq->decodedlength) {
+ if (ret != Z_OK || !rq->partial_decoding) {
+ ret = zerr(ret);
+ goto out_inflate_end;
+ }
+ }
+
+ if (rq->decodedskip)
+ memcpy(rq->out, dest + rq->decodedskip,
+ rq->decodedlength - rq->decodedskip);
+
+out_inflate_end:
+ inflateEnd(&strm);
+ if (buff)
+ free(buff);
+ return ret;
+}
+#endif
+
#if IS_ENABLED(CONFIG_LZ4)
#include <u-boot/lz4.h>
static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
@@ -93,6 +172,10 @@ int z_erofs_decompress(struct z_erofs_decompress_req *rq)
#if IS_ENABLED(CONFIG_LZ4)
if (rq->alg == Z_EROFS_COMPRESSION_LZ4)
return z_erofs_decompress_lz4(rq);
+#endif
+#if IS_ENABLED(CONFIG_ZLIB)
+ if (rq->alg == Z_EROFS_COMPRESSION_DEFLATE)
+ return z_erofs_decompress_deflate(rq);
#endif
return -EOPNOTSUPP;
}
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 158e2c68a1..5bac4fe1a1 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -304,6 +304,7 @@ enum {
enum {
Z_EROFS_COMPRESSION_LZ4 = 0,
Z_EROFS_COMPRESSION_LZMA = 1,
+ Z_EROFS_COMPRESSION_DEFLATE = 2,
Z_EROFS_COMPRESSION_MAX
};
--
2.34.1
next reply other threads:[~2024-04-14 15:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-14 15:04 Jianan Huang [this message]
2024-04-16 15:14 ` [PATCH] fs/erofs: add DEFLATE algorithm support Gao Xiang
2024-04-19 1:57 ` Tom Rini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240414150414.231027-1-jnhuang95@gmail.com \
--to=jnhuang95@gmail.com \
--cc=linux-erofs@lists.ozlabs.org \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).