@@ -6,6 +6,7 @@ config BTRFS_FS
select ZLIB_DEFLATE
select LZO_COMPRESS
select LZO_DECOMPRESS
+ select SNAPPY
help
Btrfs is a new filesystem with extents, writable snapshotting,
support for multiple devices and many more features.
@@ -7,6 +7,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.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
+ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
+ snappy.o
btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
@@ -729,6 +729,7 @@ static wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES];
struct btrfs_compress_op *btrfs_compress_op[] = {
&btrfs_zlib_compress,
&btrfs_lzo_compress,
+ &btrfs_snappy_compress,
};
int __init btrfs_init_compress(void)
@@ -79,5 +79,6 @@ 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;
#endif
@@ -415,6 +415,7 @@ struct btrfs_super_block {
#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1)
#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2)
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3)
+#define BTRFS_FEATURE_INCOMPAT_COMPRESS_SNAPPY (1ULL << 4)
#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
#define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL
@@ -422,7 +423,8 @@ struct btrfs_super_block {
(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \
BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \
- BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO)
+ BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \
+ BTRFS_FEATURE_INCOMPAT_COMPRESS_SNAPPY)
/*
* A leaf is full of items. offset and size tell us where to find
@@ -578,8 +580,9 @@ enum btrfs_compression_type {
BTRFS_COMPRESS_NONE = 0,
BTRFS_COMPRESS_ZLIB = 1,
BTRFS_COMPRESS_LZO = 2,
- BTRFS_COMPRESS_TYPES = 2,
- BTRFS_COMPRESS_LAST = 3,
+ BTRFS_COMPRESS_SNAPPY = 3,
+ BTRFS_COMPRESS_TYPES = 3,
+ BTRFS_COMPRESS_LAST = 4,
};
struct btrfs_inode_item {
@@ -1808,6 +1808,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
+ if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_SNAPPY)
+ features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_SNAPPY;
btrfs_set_super_incompat_flags(disk_super, features);
features = btrfs_super_compat_ro_flags(disk_super) &
@@ -1133,6 +1133,10 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
btrfs_set_super_incompat_flags(disk_super, features);
}
+ if (range->compress_type == BTRFS_COMPRESS_SNAPPY) {
+ features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_SNAPPY;
+ btrfs_set_super_incompat_flags(disk_super, features);
+ }
if (!file)
kfree(ra);
new file mode 100644
@@ -0,0 +1,435 @@
+/*
+ * Copyright (C) 2011 Intel Corporation
+ * Author: Andi Kleen
+ * Copyright (C) 2008 Oracle
+ *
+ * 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.
+ */
+
+/* largely copy'n'pasted from lzo.c Unify? */
+
+/* XXX: could use snappy's fragments to avoid the working buffer?
+ * However it's difficult to kmap multiple buffers.
+ */
+
+#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 <linux/snappy.h>
+#include "compression.h"
+
+#define SNAPPY_LEN 4
+
+struct workspace {
+ void *buf; /* where compressed data goes */
+ void *cbuf; /* where decompressed data goes */
+ struct snappy_env env;
+ struct list_head list;
+};
+
+static void snappy_free_workspace(struct list_head *ws)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+
+ snappy_free_env(&workspace->env);
+ vfree(workspace->buf);
+ vfree(workspace->cbuf);
+ kfree(workspace);
+}
+
+static struct list_head *snappy_alloc_workspace(void)
+{
+ struct workspace *workspace;
+
+ workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
+ if (!workspace)
+ return ERR_PTR(-ENOMEM);
+
+ workspace->buf = vmalloc(PAGE_CACHE_SIZE);
+ workspace->cbuf = vmalloc(snappy_max_compressed_length(PAGE_CACHE_SIZE));
+ if (!workspace->buf || !workspace->cbuf)
+ goto fail;
+
+ if (snappy_init_env(&workspace->env) < 0)
+ goto fail;
+
+ INIT_LIST_HEAD(&workspace->list);
+
+ return &workspace->list;
+fail:
+ snappy_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, SNAPPY_LEN);
+}
+
+static inline size_t read_compress_length(char *buf)
+{
+ __le32 dlen;
+
+ memcpy(&dlen, buf, SNAPPY_LEN);
+ return le32_to_cpu(dlen);
+}
+
+static int snappy_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 = SNAPPY_LEN;
+ tot_out = SNAPPY_LEN;
+ pages[0] = out_page;
+ nr_pages = 1;
+ pg_bytes_left = PAGE_CACHE_SIZE - SNAPPY_LEN;
+
+ /* compress at most one page of data each time */
+ in_len = min(len, PAGE_CACHE_SIZE);
+ while (tot_in < len) {
+ ret = snappy_compress(&workspace->env,
+ data_in, in_len, workspace->cbuf,
+ &out_len);
+ if (ret != 0) {
+ printk(KERN_DEBUG "btrfs uncompression 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 += SNAPPY_LEN;
+ out_offset += SNAPPY_LEN;
+ pg_bytes_left -= SNAPPY_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 < SNAPPY_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 snappy_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 = SNAPPY_LEN;
+ in_offset = SNAPPY_LEN;
+ tot_len = min_t(size_t, srclen, tot_len);
+ in_page_bytes_left = PAGE_CACHE_SIZE - SNAPPY_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 -= SNAPPY_LEN;
+ in_offset += SNAPPY_LEN;
+ tot_in += SNAPPY_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 < SNAPPY_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;
+ }
+ }
+
+ ret = -1;
+ if (snappy_uncompressed_length(buf, in_len, &out_len))
+ ret = snappy_uncompress(buf, in_len, workspace->buf);
+ if (need_unmap)
+ kunmap(pages_in[page_in_index - 1]);
+ if (ret != 0) {
+ printk(KERN_WARNING "btrfs 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 btrfs_snappy_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;
+ int ret = 0;
+ char *kaddr;
+ unsigned long bytes;
+
+ BUG_ON(srclen < SNAPPY_LEN);
+
+ in_len = read_compress_length(data_in);
+ data_in += SNAPPY_LEN;
+
+ ret = -1;
+ if (snappy_uncompressed_length(data_in, in_len, &out_len))
+ ret = snappy_uncompress(data_in, in_len, workspace->buf);
+ if (ret != 0) {
+ printk(KERN_WARNING "btrfs 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_snappy_compress = {
+ .alloc_workspace = snappy_alloc_workspace,
+ .free_workspace = snappy_free_workspace,
+ .compress_pages = snappy_compress_pages,
+ .decompress_biovec = snappy_decompress_biovec,
+ .decompress = btrfs_snappy_decompress,
+};
@@ -267,6 +267,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
} else if (strcmp(args[0].from, "lzo") == 0) {
compress_type = "lzo";
info->compress_type = BTRFS_COMPRESS_LZO;
+ } else if (strcmp(args[0].from, "snappy") == 0) {
+ compress_type = "snappy";
+ info->compress_type = BTRFS_COMPRESS_SNAPPY;
} else {
ret = -EINVAL;
goto out;
@@ -696,8 +699,12 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
if (btrfs_test_opt(root, COMPRESS)) {
if (info->compress_type == BTRFS_COMPRESS_ZLIB)
compress_type = "zlib";
- else
+ else if (info->compress_type == BTRFS_COMPRESS_SNAPPY)
+ compress_type = "snappy";
+ else if (info->compress_type == BTRFS_COMPRESS_LZO)
compress_type = "lzo";
+ else
+ compress_type = "?";
if (btrfs_test_opt(root, FORCE_COMPRESS))
seq_printf(seq, ",compress-force=%s", compress_type);
else
@@ -113,6 +113,7 @@ obj-$(CONFIG_AVERAGE) += average.o
obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
+CFLAGS_snappy.o += $(call cc-disable-warning, declaration-after-statement) -DNDEBUG=1
obj-$(CONFIG_CORDIC) += cordic.o
obj-$(CONFIG_LLIST) += llist.o