1 files changed, 33 insertions, 11 deletions

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index e61f00a192db..0fb90cbe7669 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -132,6 +132,7 @@ static int copy_compressed_data_to_page(char *compressed_data,
 	u32 sector_bytes_left;
 	u32 orig_out;
 	struct page *cur_page;
+	char *kaddr;
 
 	if ((*cur_out / PAGE_SIZE) >= max_nr_page)
 		return -E2BIG;
@@ -151,7 +152,8 @@ static int copy_compressed_data_to_page(char *compressed_data,
 		out_pages[*cur_out / PAGE_SIZE] = cur_page;
 	}
 
-	write_compress_length(page_address(cur_page) + offset_in_page(*cur_out),
+	kaddr = kmap(cur_page);
+	write_compress_length(kaddr + offset_in_page(*cur_out),
 			      compressed_size);
 	*cur_out += LZO_LEN;
 
@@ -162,6 +164,8 @@ static int copy_compressed_data_to_page(char *compressed_data,
 		u32 copy_len = min_t(u32, sectorsize - *cur_out % sectorsize,
 				     orig_out + compressed_size - *cur_out);
 
+		kunmap(cur_page);
+
 		if ((*cur_out / PAGE_SIZE) >= max_nr_page)
 			return -E2BIG;
 
@@ -173,8 +177,9 @@ static int copy_compressed_data_to_page(char *compressed_data,
 				return -ENOMEM;
 			out_pages[*cur_out / PAGE_SIZE] = cur_page;
 		}
+		kaddr = kmap(cur_page);
 
-		memcpy(page_address(cur_page) + offset_in_page(*cur_out),
+		memcpy(kaddr + offset_in_page(*cur_out),
 		       compressed_data + *cur_out - orig_out, copy_len);
 
 		*cur_out += copy_len;
@@ -186,12 +191,15 @@ static int copy_compressed_data_to_page(char *compressed_data,
 	 */
 	sector_bytes_left = round_up(*cur_out, sectorsize) - *cur_out;
 	if (sector_bytes_left >= LZO_LEN || sector_bytes_left == 0)
-		return 0;
+		goto out;
 
 	/* The remaining size is not enough, pad it with zeros */
-	memset(page_address(cur_page) + offset_in_page(*cur_out), 0,
+	memset(kaddr + offset_in_page(*cur_out), 0,
 	       sector_bytes_left);
 	*cur_out += sector_bytes_left;
+
+out:
+	kunmap(cur_page);
 	return 0;
 }
 
@@ -202,6 +210,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 	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 */
@@ -221,6 +230,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 	 */
 	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;
@@ -235,10 +245,12 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 		/* Compress at most one sector of data each time */
 		in_len = min_t(u32, start + len - cur_in, sectorsize - sector_off);
 		ASSERT(in_len);
-		ret = lzo1x_1_compress(page_address(page_in) +
+		data_in = kmap(page_in);
+		ret = lzo1x_1_compress(data_in +
 				       offset_in_page(cur_in), in_len,
 				       workspace->cbuf, &out_len,
 				       workspace->mem);
+		kunmap(page_in);
 		if (ret < 0) {
 			pr_debug("BTRFS: lzo in loop returned %d\n", ret);
 			ret = -EIO;
@@ -270,7 +282,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 	}
 
 	/* Store the size of all chunks of compressed data */
-	write_compress_length(page_address(pages[0]), cur_out);
+	sizes_ptr = kmap_local_page(pages[0]);
+	write_compress_length(sizes_ptr, cur_out);
+	kunmap_local(sizes_ptr);
 
 	ret = 0;
 	*total_out = cur_out;
@@ -293,6 +307,7 @@ static void copy_compressed_segment(struct compressed_bio *cb,
 	u32 orig_in = *cur_in;
 
 	while (*cur_in < orig_in + len) {
+		char *kaddr;
 		struct page *cur_page;
 		u32 copy_len = min_t(u32, PAGE_SIZE - offset_in_page(*cur_in),
 					  orig_in + len - *cur_in);
@@ -300,9 +315,11 @@ static void copy_compressed_segment(struct compressed_bio *cb,
 		ASSERT(copy_len);
 		cur_page = cb->compressed_pages[*cur_in / PAGE_SIZE];
 
+		kaddr = kmap(cur_page);
 		memcpy(dest + *cur_in - orig_in,
-			page_address(cur_page) + offset_in_page(*cur_in),
+			kaddr + offset_in_page(*cur_in),
 			copy_len);
+		kunmap(cur_page);
 
 		*cur_in += copy_len;
 	}
@@ -313,6 +330,7 @@ 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 = btrfs_sb(cb->inode->i_sb);
 	const u32 sectorsize = fs_info->sectorsize;
+	char *kaddr;
 	int ret;
 	/* Compressed data length, can be unaligned */
 	u32 len_in;
@@ -321,7 +339,9 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 	/* Bytes decompressed so far */
 	u32 cur_out = 0;
 
-	len_in = read_compress_length(page_address(cb->compressed_pages[0]));
+	kaddr = kmap(cb->compressed_pages[0]);
+	len_in = read_compress_length(kaddr);
+	kunmap(cb->compressed_pages[0]);
 	cur_in += LZO_LEN;
 
 	/*
@@ -355,8 +375,9 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		       (cur_in + LZO_LEN - 1) / sectorsize);
 		cur_page = cb->compressed_pages[cur_in / PAGE_SIZE];
 		ASSERT(cur_page);
-		seg_len = read_compress_length(page_address(cur_page) +
-					       offset_in_page(cur_in));
+		kaddr = kmap(cur_page);
+		seg_len = read_compress_length(kaddr + offset_in_page(cur_in));
+		kunmap(cur_page);
 		cur_in += LZO_LEN;
 
 		/* Copy the compressed segment payload into workspace */
@@ -441,7 +462,7 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	destlen = min_t(unsigned long, destlen, PAGE_SIZE);
 	bytes = min_t(unsigned long, destlen, out_len - start_byte);
 
-	kaddr = page_address(dest_page);
+	kaddr = kmap_local_page(dest_page);
 	memcpy(kaddr, workspace->buf + start_byte, bytes);
 
 	/*
@@ -451,6 +472,7 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	 */
 	if (bytes < destlen)
 		memset(kaddr+bytes, 0, destlen-bytes);
+	kunmap_local(kaddr);
 out:
 	return ret;
 }