Signed-off-by: David Sterba <dste...@suse.cz>
---
fs/btrfs/Makefile | 2 +-
fs/btrfs/compression.c | 1 +
fs/btrfs/compression.h | 1 +
fs/btrfs/lz4_wrapper.c | 429 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/lzo.c | 2 +
fs/btrfs/super.c | 3 -
6 files changed, 434 insertions(+), 4 deletions(-)
create mode 100644 fs/btrfs/lz4_wrapper.c
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 11f8c4e..7bb7497 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -8,7 +8,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o
root-tree.o dir-item.o \
extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
export.o tree-log.o free-space-cache.o zlib.o lzo.o \
compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
- reada.o backref.o ulist.o snappy.o lz4.o
+ reada.o backref.o ulist.o snappy.o lz4.o lz4_wrapper.o
btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index f85f7fd..93b481e 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -731,6 +731,7 @@ struct btrfs_compress_op *btrfs_compress_op[] = {
&btrfs_zlib_compress,
&btrfs_lzo_compress,
&btrfs_snappy_compress,
+ &btrfs_lz4_compress,
};
int __init btrfs_init_compress(void)
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 971a425..d8e8e73 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -80,5 +80,6 @@ struct btrfs_compress_op {
extern struct btrfs_compress_op btrfs_zlib_compress;
extern struct btrfs_compress_op btrfs_lzo_compress;
extern struct btrfs_compress_op btrfs_snappy_compress;
+extern struct btrfs_compress_op btrfs_lz4_compress;
#endif
diff --git a/fs/btrfs/lz4_wrapper.c b/fs/btrfs/lz4_wrapper.c
new file mode 100644
index 0000000..bff9b1b
--- /dev/null
+++ b/fs/btrfs/lz4_wrapper.c
@@ -0,0 +1,429 @@
+/*
+ * Copyright (C) 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include "lz4.h"
+#include "compression.h"
+
+#define LZ4_LEN 4
+#define LZ4_CHUNK_SIZE (4096)
+#define LZ4_MAX_WORKBUF 2*LZ4_CHUNK_SIZE
+
+struct workspace {
+ void *mem; /* work memory for compression */
+ void *buf; /* where compressed data goes */
+ void *cbuf; /* where decompressed data goes */
+ struct list_head list;
+};
+
+static void lz4_free_workspace(struct list_head *ws)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+
+ vfree(workspace->buf);
+ vfree(workspace->cbuf);
+ vfree(workspace->mem);
+ kfree(workspace);
+}
+
+static struct list_head *lz4_alloc_workspace(void)
+{
+ struct workspace *workspace;
+
+ workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
+ if (!workspace)
+ return ERR_PTR(-ENOMEM);
+
+ workspace->mem = vmalloc(LZ4_context64k_size());
+ workspace->buf = vmalloc(LZ4_MAX_WORKBUF);
+ workspace->cbuf = vmalloc(LZ4_MAX_WORKBUF);
+ if (!workspace->mem || !workspace->buf || !workspace->cbuf)
+ goto fail;
+
+ INIT_LIST_HEAD(&workspace->list);
+
+ return &workspace->list;
+fail:
+ lz4_free_workspace(&workspace->list);
+ return ERR_PTR(-ENOMEM);
+}
+
+static inline void write_compress_length(char *buf, size_t len)
+{
+ __le32 dlen;
+
+ dlen = cpu_to_le32(len);
+ memcpy(buf, &dlen, LZ4_LEN);
+}
+
+static inline size_t read_compress_length(char *buf)
+{
+ __le32 dlen;
+
+ memcpy(&dlen, buf, LZ4_LEN);
+ return le32_to_cpu(dlen);
+}
+
+static int lz4_compress_pages(struct list_head *ws,
+ struct address_space *mapping,
+ u64 start, unsigned long len,
+ struct page **pages,
+ unsigned long nr_dest_pages,
+ unsigned long *out_pages,
+ unsigned long *total_in,
+ unsigned long *total_out,
+ unsigned long max_out)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+ int ret = 0;
+ char *data_in;
+ char *cpage_out;
+ int nr_pages = 0;
+ struct page *in_page = NULL;
+ struct page *out_page = NULL;
+ unsigned long bytes_left;
+
+ size_t in_len;
+ size_t out_len;
+ char *buf;
+ unsigned long tot_in = 0;
+ unsigned long tot_out = 0;
+ unsigned long pg_bytes_left;
+ unsigned long out_offset;
+ unsigned long bytes;
+
+ *out_pages = 0;
+ *total_out = 0;
+ *total_in = 0;
+
+ in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+ data_in = kmap(in_page);
+
+ /*
+ * store the size of all chunks of compressed data in
+ * the first 4 bytes
+ */
+ out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (out_page == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ cpage_out = kmap(out_page);
+ out_offset = LZ4_LEN;
+ tot_out = LZ4_LEN;
+ pages[0] = out_page;
+ nr_pages = 1;
+ pg_bytes_left = PAGE_CACHE_SIZE - LZ4_LEN;
+
+ /* compress at most one page of data each time */
+ in_len = min(len, PAGE_CACHE_SIZE);
+ while (tot_in < len) {
+ out_len = LZ4_compress64kCtx(&workspace->mem, data_in,
+ workspace->cbuf, in_len);
+ if (out_len <= 0) {
+ printk(KERN_DEBUG
+ "btrfs: lz4 compress in loop returned %d\n",
+ ret);
+ ret = -1;
+ goto out;
+ }
+
+ /* store the size of this chunk of compressed data */
+ write_compress_length(cpage_out + out_offset, out_len);
+ tot_out += LZ4_LEN;
+ out_offset += LZ4_LEN;
+ pg_bytes_left -= LZ4_LEN;
+
+ tot_in += in_len;
+ tot_out += out_len;
+
+ /* copy bytes from the working buffer into the pages */
+ buf = workspace->cbuf;
+ while (out_len) {
+ bytes = min_t(unsigned long, pg_bytes_left, out_len);
+
+ memcpy(cpage_out + out_offset, buf, bytes);
+
+ out_len -= bytes;
+ pg_bytes_left -= bytes;
+ buf += bytes;
+ out_offset += bytes;
+
+ /*
+ * we need another page for writing out.
+ *
+ * Note if there's less than 4 bytes left, we just
+ * skip to a new page.
+ */
+ if ((out_len == 0 && pg_bytes_left < LZ4_LEN) ||
+ pg_bytes_left == 0) {
+ if (pg_bytes_left) {
+ memset(cpage_out + out_offset, 0,
+ pg_bytes_left);
+ tot_out += pg_bytes_left;
+ }
+
+ /* we're done, don't allocate new page */
+ if (out_len == 0 && tot_in >= len)
+ break;
+
+ kunmap(out_page);
+ if (nr_pages == nr_dest_pages) {
+ out_page = NULL;
+ ret = -1;
+ goto out;
+ }
+
+ out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+ if (out_page == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ cpage_out = kmap(out_page);
+ pages[nr_pages++] = out_page;
+
+ pg_bytes_left = PAGE_CACHE_SIZE;
+ out_offset = 0;
+ }
+ }
+
+ /* we're making it bigger, give up */
+ if (tot_in > 8192 && tot_in < tot_out)
+ goto out;
+
+ /* we're all done */
+ if (tot_in >= len)
+ break;
+
+ if (tot_out > max_out)
+ break;
+
+ bytes_left = len - tot_in;
+ kunmap(in_page);
+ page_cache_release(in_page);
+
+ start += PAGE_CACHE_SIZE;
+ in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
+ data_in = kmap(in_page);
+ in_len = min(bytes_left, PAGE_CACHE_SIZE);
+ }
+
+ if (tot_out > tot_in)
+ goto out;
+
+ /* store the size of all chunks of compressed data */
+ cpage_out = kmap(pages[0]);
+ write_compress_length(cpage_out, tot_out);
+
+ kunmap(pages[0]);
+
+ ret = 0;
+ *total_out = tot_out;
+ *total_in = tot_in;
+out:
+ *out_pages = nr_pages;
+ if (out_page)
+ kunmap(out_page);
+
+ if (in_page) {
+ kunmap(in_page);
+ page_cache_release(in_page);
+ }
+
+ return ret;
+}
+
+static int lz4_decompress_biovec(struct list_head *ws,
+ struct page **pages_in,
+ u64 disk_start,
+ struct bio_vec *bvec,
+ int vcnt,
+ size_t srclen)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+ int ret = 0, ret2;
+ char *data_in;
+ unsigned long page_in_index = 0;
+ unsigned long page_out_index = 0;
+ unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) /
+ PAGE_CACHE_SIZE;
+ unsigned long buf_start;
+ unsigned long buf_offset = 0;
+ unsigned long bytes;
+ unsigned long working_bytes;
+ unsigned long pg_offset;
+
+ size_t in_len;
+ size_t out_len;
+ unsigned long in_offset;
+ unsigned long in_page_bytes_left;
+ unsigned long tot_in;
+ unsigned long tot_out;
+ unsigned long tot_len;
+ char *buf;
+ bool may_late_unmap, need_unmap;
+
+ data_in = kmap(pages_in[0]);
+ tot_len = read_compress_length(data_in);
+
+ tot_in = LZ4_LEN;
+ in_offset = LZ4_LEN;
+ tot_len = min_t(size_t, srclen, tot_len);
+ in_page_bytes_left = PAGE_CACHE_SIZE - LZ4_LEN;
+
+ tot_out = 0;
+ pg_offset = 0;
+
+ while (tot_in < tot_len) {
+ in_len = read_compress_length(data_in + in_offset);
+ in_page_bytes_left -= LZ4_LEN;
+ in_offset += LZ4_LEN;
+ tot_in += LZ4_LEN;
+
+ tot_in += in_len;
+ working_bytes = in_len;
+ may_late_unmap = need_unmap = false;
+
+ /* fast path: avoid using the working buffer */
+ if (in_page_bytes_left >= in_len) {
+ buf = data_in + in_offset;
+ bytes = in_len;
+ may_late_unmap = true;
+ goto cont;
+ }
+
+ /* copy bytes from the pages into the working buffer */
+ buf = workspace->cbuf;
+ buf_offset = 0;
+ while (working_bytes) {
+ bytes = min(working_bytes, in_page_bytes_left);
+
+ memcpy(buf + buf_offset, data_in + in_offset, bytes);
+ buf_offset += bytes;
+cont:
+ working_bytes -= bytes;
+ in_page_bytes_left -= bytes;
+ in_offset += bytes;
+
+ /* check if we need to pick another page */
+ if ((working_bytes == 0 && in_page_bytes_left < LZ4_LEN)
+ || in_page_bytes_left == 0) {
+ tot_in += in_page_bytes_left;
+
+ if (working_bytes == 0 && tot_in >= tot_len)
+ break;
+
+ if (page_in_index + 1 >= total_pages_in) {
+ ret = -1;
+ goto done;
+ }
+
+ if (may_late_unmap)
+ need_unmap = true;
+ else
+ kunmap(pages_in[page_in_index]);
+
+ data_in = kmap(pages_in[++page_in_index]);
+
+ in_page_bytes_left = PAGE_CACHE_SIZE;
+ in_offset = 0;
+ }
+ }
+
+ out_len = LZ4_uncompress_unknownOutputSize(buf, workspace->buf,
+ in_len, LZ4_CHUNK_SIZE);
+ if (need_unmap)
+ kunmap(pages_in[page_in_index - 1]);
+ if (out_len < 0) {
+ printk(KERN_WARNING "btrfs: lz4 decompress failed\n");
+ ret = -1;
+ break;
+ }
+
+ buf_start = tot_out;
+ tot_out += out_len;
+
+ ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
+ tot_out, disk_start,
+ bvec, vcnt,
+ &page_out_index, &pg_offset);
+ if (ret2 == 0)
+ break;
+ }
+done:
+ kunmap(pages_in[page_in_index]);
+ return ret;
+}
+
+static int lz4_decompress(struct list_head *ws, unsigned char *data_in,
+ struct page *dest_page,
+ unsigned long start_byte,
+ size_t srclen, size_t destlen)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+ size_t in_len;
+ size_t out_len;
+ size_t tot_len;
+ int ret = 0;
+ char *kaddr;
+ unsigned long bytes;
+
+ BUG_ON(srclen < LZ4_LEN);
+
+ tot_len = read_compress_length(data_in);
+ data_in += LZ4_LEN;
+
+ in_len = read_compress_length(data_in);
+ data_in += LZ4_LEN;
+
+ out_len = LZ4_uncompress_unknownOutputSize(data_in, workspace->buf,
+ in_len, LZ4_CHUNK_SIZE);
+ if (out_len < 0) {
+ printk(KERN_WARNING "btrfs: lz4 decompress failed\n");
+ ret = -1;
+ goto out;
+ }
+
+ if (out_len < start_byte) {
+ ret = -1;
+ goto out;
+ }
+
+ bytes = min_t(unsigned long, destlen, out_len - start_byte);
+
+ kaddr = kmap_atomic(dest_page, KM_USER0);
+ memcpy(kaddr, workspace->buf + start_byte, bytes);
+ kunmap_atomic(kaddr, KM_USER0);
+out:
+ return ret;
+}
+
+struct btrfs_compress_op btrfs_lz4_compress = {
+ .alloc_workspace = lz4_alloc_workspace,
+ .free_workspace = lz4_free_workspace,
+ .compress_pages = lz4_compress_pages,
+ .decompress_biovec = lz4_decompress_biovec,
+ .decompress = lz4_decompress,
+};
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index a178f5e..3be72d3 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -16,6 +16,8 @@
* Boston, MA 021110-1307, USA.
*/
+/* Based on lzo.c wrapper */
+
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b65c94b..68c980e 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -290,9 +290,6 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
} else if (strcmp(args[0].from, "lz4") == 0) {
compress_type = "lz4";
info->compress_type = BTRFS_COMPRESS_LZ4;
- /* remove when implemented */
- ret = -EINVAL;
- goto out;
} else {
ret = -EINVAL;
goto out;
--
1.7.8
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