Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 493 insertions, 0 deletions

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
new file mode 100644
index 0000000000..d3fcfc628a
--- /dev/null
+++ b/fs/btrfs/lzo.c
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/lzo.h>
+#include <linux/refcount.h>
+#include "messages.h"
+#include "compression.h"
+#include "ctree.h"
+#include "super.h"
+#include "btrfs_inode.h"
+
+#define LZO_LEN	4
+
+/*
+ * Btrfs LZO compression format
+ *
+ * Regular and inlined LZO compressed data extents consist of:
+ *
+ * 1.  Header
+ *     Fixed size. LZO_LEN (4) bytes long, LE32.
+ *     Records the total size (including the header) of compressed data.
+ *
+ * 2.  Segment(s)
+ *     Variable size. Each segment includes one segment header, followed by data
+ *     payload.
+ *     One regular LZO compressed extent can have one or more segments.
+ *     For inlined LZO compressed extent, only one segment is allowed.
+ *     One segment represents at most one sector of uncompressed data.
+ *
+ * 2.1 Segment header
+ *     Fixed size. LZO_LEN (4) bytes long, LE32.
+ *     Records the total size of the segment (not including the header).
+ *     Segment header never crosses sector boundary, thus it's possible to
+ *     have at most 3 padding zeros at the end of the sector.
+ *
+ * 2.2 Data Payload
+ *     Variable size. Size up limit should be lzo1x_worst_compress(sectorsize)
+ *     which is 4419 for a 4KiB sectorsize.
+ *
+ * Example with 4K sectorsize:
+ * Page 1:
+ *          0     0x2   0x4   0x6   0x8   0xa   0xc   0xe     0x10
+ * 0x0000   |  Header   | SegHdr 01 | Data payload 01 ...     |
+ * ...
+ * 0x0ff0   | SegHdr  N | Data payload  N     ...          |00|
+ *                                                          ^^ padding zeros
+ * Page 2:
+ * 0x1000   | SegHdr N+1| Data payload N+1 ...                |
+ */
+
+#define WORKSPACE_BUF_LENGTH	(lzo1x_worst_compress(PAGE_SIZE))
+#define WORKSPACE_CBUF_LENGTH	(lzo1x_worst_compress(PAGE_SIZE))
+
+struct workspace {
+	void *mem;
+	void *buf;	/* where decompressed data goes */
+	void *cbuf;	/* where compressed data goes */
+	struct list_head list;
+};
+
+static struct workspace_manager wsm;
+
+void lzo_free_workspace(struct list_head *ws)
+{
+	struct workspace *workspace = list_entry(ws, struct workspace, list);
+
+	kvfree(workspace->buf);
+	kvfree(workspace->cbuf);
+	kvfree(workspace->mem);
+	kfree(workspace);
+}
+
+struct list_head *lzo_alloc_workspace(unsigned int level)
+{
+	struct workspace *workspace;
+
+	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
+	if (!workspace)
+		return ERR_PTR(-ENOMEM);
+
+	workspace->mem = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL | __GFP_NOWARN);
+	workspace->buf = kvmalloc(WORKSPACE_BUF_LENGTH, GFP_KERNEL | __GFP_NOWARN);
+	workspace->cbuf = kvmalloc(WORKSPACE_CBUF_LENGTH, GFP_KERNEL | __GFP_NOWARN);
+	if (!workspace->mem || !workspace->buf || !workspace->cbuf)
+		goto fail;
+
+	INIT_LIST_HEAD(&workspace->list);
+
+	return &workspace->list;
+fail:
+	lzo_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, LZO_LEN);
+}
+
+static inline size_t read_compress_length(const char *buf)
+{
+	__le32 dlen;
+
+	memcpy(&dlen, buf, LZO_LEN);
+	return le32_to_cpu(dlen);
+}
+
+/*
+ * Will do:
+ *
+ * - Write a segment header into the destination
+ * - Copy the compressed buffer into the destination
+ * - Make sure we have enough space in the last sector to fit a segment header
+ *   If not, we will pad at most (LZO_LEN (4)) - 1 bytes of zeros.
+ *
+ * Will allocate new pages when needed.
+ */
+static int copy_compressed_data_to_page(char *compressed_data,
+					size_t compressed_size,
+					struct page **out_pages,
+					unsigned long max_nr_page,
+					u32 *cur_out,
+					const u32 sectorsize)
+{
+	u32 sector_bytes_left;
+	u32 orig_out;
+	struct page *cur_page;
+	char *kaddr;
+
+	if ((*cur_out / PAGE_SIZE) >= max_nr_page)
+		return -E2BIG;
+
+	/*
+	 * We never allow a segment header crossing sector boundary, previous
+	 * run should ensure we have enough space left inside the sector.
+	 */
+	ASSERT((*cur_out / sectorsize) == (*cur_out + LZO_LEN - 1) / sectorsize);
+
+	cur_page = out_pages[*cur_out / PAGE_SIZE];
+	/* Allocate a new page */
+	if (!cur_page) {
+		cur_page = alloc_page(GFP_NOFS);
+		if (!cur_page)
+			return -ENOMEM;
+		out_pages[*cur_out / PAGE_SIZE] = cur_page;
+	}
+
+	kaddr = kmap_local_page(cur_page);
+	write_compress_length(kaddr + offset_in_page(*cur_out),
+			      compressed_size);
+	*cur_out += LZO_LEN;
+
+	orig_out = *cur_out;
+
+	/* Copy compressed data */
+	while (*cur_out - orig_out < compressed_size) {
+		u32 copy_len = min_t(u32, sectorsize - *cur_out % sectorsize,
+				     orig_out + compressed_size - *cur_out);
+
+		kunmap_local(kaddr);
+
+		if ((*cur_out / PAGE_SIZE) >= max_nr_page)
+			return -E2BIG;
+
+		cur_page = out_pages[*cur_out / PAGE_SIZE];
+		/* Allocate a new page */
+		if (!cur_page) {
+			cur_page = alloc_page(GFP_NOFS);
+			if (!cur_page)
+				return -ENOMEM;
+			out_pages[*cur_out / PAGE_SIZE] = cur_page;
+		}
+		kaddr = kmap_local_page(cur_page);
+
+		memcpy(kaddr + offset_in_page(*cur_out),
+		       compressed_data + *cur_out - orig_out, copy_len);
+
+		*cur_out += copy_len;
+	}
+
+	/*
+	 * Check if we can fit the next segment header into the remaining space
+	 * of the sector.
+	 */
+	sector_bytes_left = round_up(*cur_out, sectorsize) - *cur_out;
+	if (sector_bytes_left >= LZO_LEN || sector_bytes_left == 0)
+		goto out;
+
+	/* The remaining size is not enough, pad it with zeros */
+	memset(kaddr + offset_in_page(*cur_out), 0,
+	       sector_bytes_left);
+	*cur_out += sector_bytes_left;
+
+out:
+	kunmap_local(kaddr);
+	return 0;
+}
+
+int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out)
+{
+	struct workspace *workspace = list_entry(ws, struct workspace, list);
+	const u32 sectorsize = btrfs_sb(mapping->host->i_sb)->sectorsize;
+	struct page *page_in = NULL;
+	char *sizes_ptr;
+	const unsigned long max_nr_page = *out_pages;
+	int ret = 0;
+	/* Points to the file offset of input data */
+	u64 cur_in = start;
+	/* Points to the current output byte */
+	u32 cur_out = 0;
+	u32 len = *total_out;
+
+	ASSERT(max_nr_page > 0);
+	*out_pages = 0;
+	*total_out = 0;
+	*total_in = 0;
+
+	/*
+	 * Skip the header for now, we will later come back and write the total
+	 * compressed size
+	 */
+	cur_out += LZO_LEN;
+	while (cur_in < start + len) {
+		char *data_in;
+		const u32 sectorsize_mask = sectorsize - 1;
+		u32 sector_off = (cur_in - start) & sectorsize_mask;
+		u32 in_len;
+		size_t out_len;
+
+		/* Get the input page first */
+		if (!page_in) {
+			page_in = find_get_page(mapping, cur_in >> PAGE_SHIFT);
+			ASSERT(page_in);
+		}
+
+		/* Compress at most one sector of data each time */
+		in_len = min_t(u32, start + len - cur_in, sectorsize - sector_off);
+		ASSERT(in_len);
+		data_in = kmap_local_page(page_in);
+		ret = lzo1x_1_compress(data_in +
+				       offset_in_page(cur_in), in_len,
+				       workspace->cbuf, &out_len,
+				       workspace->mem);
+		kunmap_local(data_in);
+		if (ret < 0) {
+			pr_debug("BTRFS: lzo in loop returned %d\n", ret);
+			ret = -EIO;
+			goto out;
+		}
+
+		ret = copy_compressed_data_to_page(workspace->cbuf, out_len,
+						   pages, max_nr_page,
+						   &cur_out, sectorsize);
+		if (ret < 0)
+			goto out;
+
+		cur_in += in_len;
+
+		/*
+		 * Check if we're making it bigger after two sectors.  And if
+		 * it is so, give up.
+		 */
+		if (cur_in - start > sectorsize * 2 && cur_in - start < cur_out) {
+			ret = -E2BIG;
+			goto out;
+		}
+
+		/* Check if we have reached page boundary */
+		if (PAGE_ALIGNED(cur_in)) {
+			put_page(page_in);
+			page_in = NULL;
+		}
+	}
+
+	/* Store the size of all chunks of compressed data */
+	sizes_ptr = kmap_local_page(pages[0]);
+	write_compress_length(sizes_ptr, cur_out);
+	kunmap_local(sizes_ptr);
+
+	ret = 0;
+	*total_out = cur_out;
+	*total_in = cur_in - start;
+out:
+	if (page_in)
+		put_page(page_in);
+	*out_pages = DIV_ROUND_UP(cur_out, PAGE_SIZE);
+	return ret;
+}
+
+/*
+ * Copy the compressed segment payload into @dest.
+ *
+ * For the payload there will be no padding, just need to do page switching.
+ */
+static void copy_compressed_segment(struct compressed_bio *cb,
+				    char *dest, u32 len, u32 *cur_in)
+{
+	u32 orig_in = *cur_in;
+
+	while (*cur_in < orig_in + len) {
+		struct page *cur_page;
+		u32 copy_len = min_t(u32, PAGE_SIZE - offset_in_page(*cur_in),
+					  orig_in + len - *cur_in);
+
+		ASSERT(copy_len);
+		cur_page = cb->compressed_pages[*cur_in / PAGE_SIZE];
+
+		memcpy_from_page(dest + *cur_in - orig_in, cur_page,
+				 offset_in_page(*cur_in), copy_len);
+
+		*cur_in += copy_len;
+	}
+}
+
+int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
+{
+	struct workspace *workspace = list_entry(ws, struct workspace, list);
+	const struct btrfs_fs_info *fs_info = cb->bbio.inode->root->fs_info;
+	const u32 sectorsize = fs_info->sectorsize;
+	char *kaddr;
+	int ret;
+	/* Compressed data length, can be unaligned */
+	u32 len_in;
+	/* Offset inside the compressed data */
+	u32 cur_in = 0;
+	/* Bytes decompressed so far */
+	u32 cur_out = 0;
+
+	kaddr = kmap_local_page(cb->compressed_pages[0]);
+	len_in = read_compress_length(kaddr);
+	kunmap_local(kaddr);
+	cur_in += LZO_LEN;
+
+	/*
+	 * LZO header length check
+	 *
+	 * The total length should not exceed the maximum extent length,
+	 * and all sectors should be used.
+	 * If this happens, it means the compressed extent is corrupted.
+	 */
+	if (len_in > min_t(size_t, BTRFS_MAX_COMPRESSED, cb->compressed_len) ||
+	    round_up(len_in, sectorsize) < cb->compressed_len) {
+		btrfs_err(fs_info,
+			"invalid lzo header, lzo len %u compressed len %u",
+			len_in, cb->compressed_len);
+		return -EUCLEAN;
+	}
+
+	/* Go through each lzo segment */
+	while (cur_in < len_in) {
+		struct page *cur_page;
+		/* Length of the compressed segment */
+		u32 seg_len;
+		u32 sector_bytes_left;
+		size_t out_len = lzo1x_worst_compress(sectorsize);
+
+		/*
+		 * We should always have enough space for one segment header
+		 * inside current sector.
+		 */
+		ASSERT(cur_in / sectorsize ==
+		       (cur_in + LZO_LEN - 1) / sectorsize);
+		cur_page = cb->compressed_pages[cur_in / PAGE_SIZE];
+		ASSERT(cur_page);
+		kaddr = kmap_local_page(cur_page);
+		seg_len = read_compress_length(kaddr + offset_in_page(cur_in));
+		kunmap_local(kaddr);
+		cur_in += LZO_LEN;
+
+		if (seg_len > WORKSPACE_CBUF_LENGTH) {
+			/*
+			 * seg_len shouldn't be larger than we have allocated
+			 * for workspace->cbuf
+			 */
+			btrfs_err(fs_info, "unexpectedly large lzo segment len %u",
+					seg_len);
+			return -EIO;
+		}
+
+		/* Copy the compressed segment payload into workspace */
+		copy_compressed_segment(cb, workspace->cbuf, seg_len, &cur_in);
+
+		/* Decompress the data */
+		ret = lzo1x_decompress_safe(workspace->cbuf, seg_len,
+					    workspace->buf, &out_len);
+		if (ret != LZO_E_OK) {
+			btrfs_err(fs_info, "failed to decompress");
+			return -EIO;
+		}
+
+		/* Copy the data into inode pages */
+		ret = btrfs_decompress_buf2page(workspace->buf, out_len, cb, cur_out);
+		cur_out += out_len;
+
+		/* All data read, exit */
+		if (ret == 0)
+			return 0;
+		ret = 0;
+
+		/* Check if the sector has enough space for a segment header */
+		sector_bytes_left = sectorsize - (cur_in % sectorsize);
+		if (sector_bytes_left >= LZO_LEN)
+			continue;
+
+		/* Skip the padding zeros */
+		cur_in += sector_bytes_left;
+	}
+
+	return 0;
+}
+
+int lzo_decompress(struct list_head *ws, const u8 *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 max_segment_len = WORKSPACE_BUF_LENGTH;
+	int ret = 0;
+	char *kaddr;
+	unsigned long bytes;
+
+	if (srclen < LZO_LEN || srclen > max_segment_len + LZO_LEN * 2)
+		return -EUCLEAN;
+
+	in_len = read_compress_length(data_in);
+	if (in_len != srclen)
+		return -EUCLEAN;
+	data_in += LZO_LEN;
+
+	in_len = read_compress_length(data_in);
+	if (in_len != srclen - LZO_LEN * 2) {
+		ret = -EUCLEAN;
+		goto out;
+	}
+	data_in += LZO_LEN;
+
+	out_len = PAGE_SIZE;
+	ret = lzo1x_decompress_safe(data_in, in_len, workspace->buf, &out_len);
+	if (ret != LZO_E_OK) {
+		pr_warn("BTRFS: decompress failed!\n");
+		ret = -EIO;
+		goto out;
+	}
+
+	if (out_len < start_byte) {
+		ret = -EIO;
+		goto out;
+	}
+
+	/*
+	 * the caller is already checking against PAGE_SIZE, but lets
+	 * move this check closer to the memcpy/memset
+	 */
+	destlen = min_t(unsigned long, destlen, PAGE_SIZE);
+	bytes = min_t(unsigned long, destlen, out_len - start_byte);
+
+	kaddr = kmap_local_page(dest_page);
+	memcpy(kaddr, workspace->buf + start_byte, bytes);
+
+	/*
+	 * btrfs_getblock is doing a zero on the tail of the page too,
+	 * but this will cover anything missing from the decompressed
+	 * data.
+	 */
+	if (bytes < destlen)
+		memset(kaddr+bytes, 0, destlen-bytes);
+	kunmap_local(kaddr);
+out:
+	return ret;
+}
+
+const struct btrfs_compress_op btrfs_lzo_compress = {
+	.workspace_manager	= &wsm,
+	.max_level		= 1,
+	.default_level		= 1,
+};