8 files changed, 527 insertions, 8 deletions

diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 7bb3c020e570..ecb9fd3be143 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -4,6 +4,8 @@ config BTRFS_FS
         select LIBCRC32C
         select ZLIB_INFLATE
         select ZLIB_DEFLATE
+        select LZO_COMPRESS
+        select LZO_DECOMPRESS
         help
           Btrfs is a new filesystem with extents, writable snapshotting,
           support for multiple devices and many more features.
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index a35eb36b32fd..31610ea73aec 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -6,5 +6,5 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
            transaction.o inode.o file.o tree-defrag.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 acl.o free-space-cache.o zlib.o \
+           export.o tree-log.o acl.o free-space-cache.o zlib.o lzo.o \
            compression.o delayed-ref.o relocation.o
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 6638c9877720..8faa2df9e719 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -691,6 +691,7 @@ static wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES];
 
 struct btrfs_compress_op *btrfs_compress_op[] = {
         &btrfs_zlib_compress,
+        &btrfs_lzo_compress,
 };
 
 int __init btrfs_init_compress(void)
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 9b5f2f365b79..f7ce217113fa 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -73,5 +73,6 @@ struct btrfs_compress_op {
 };
 
 extern struct btrfs_compress_op btrfs_zlib_compress;
+extern struct btrfs_compress_op btrfs_lzo_compress;
 
 #endif
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e06534438592..53b984623983 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -398,13 +398,15 @@ struct btrfs_super_block {
 #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF    (1ULL << 0)
 #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_COMPAT_SUPP               0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SUPP            0ULL
 #define BTRFS_FEATURE_INCOMPAT_SUPP                     \
         (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |         \
          BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |        \
-         BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+         BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |          \
+         BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO)
 
 /*
  * A leaf is full of items. offset and size tell us where to find
@@ -553,8 +555,9 @@ struct btrfs_timespec {
 enum btrfs_compression_type {
         BTRFS_COMPRESS_NONE  = 0,
         BTRFS_COMPRESS_ZLIB  = 1,
-        BTRFS_COMPRESS_TYPES = 1,
-        BTRFS_COMPRESS_LAST  = 2,
+        BTRFS_COMPRESS_LZO   = 2,
+        BTRFS_COMPRESS_TYPES = 2,
+        BTRFS_COMPRESS_LAST  = 3,
 };
 
 struct btrfs_inode_item {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a5d2249e6da5..f88eb2ce7919 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1744,10 +1744,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         }
 
         features = btrfs_super_incompat_flags(disk_super);
-        if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
-                features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
-                btrfs_set_super_incompat_flags(disk_super, features);
-        }
+        features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
+        if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
+                features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
+        btrfs_set_super_incompat_flags(disk_super, features);
 
         features = btrfs_super_compat_ro_flags(disk_super) &
                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
new file mode 100644
index 000000000000..523b144e2aec
--- /dev/null
+++ b/fs/btrfs/lzo.c
@@ -0,0 +1,509 @@
+/*
+ * 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 <linux/lzo.h>
+#include "compression.h"
+
+#define LZO_LEN 4
+
+struct workspace {
+        void *mem;
+        void *buf;      /* where compressed data goes */
+        void *cbuf;     /* where decompressed data goes */
+        struct list_head list;
+};
+
+static void lzo_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 *lzo_alloc_workspace(void)
+{
+        struct workspace *workspace;
+
+        workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
+        if (!workspace)
+                return ERR_PTR(-ENOMEM);
+
+        workspace->mem = vmalloc(LZO1X_MEM_COMPRESS);
+        workspace->buf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
+        workspace->cbuf = vmalloc(lzo1x_worst_compress(PAGE_CACHE_SIZE));
+        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(char *buf)
+{
+        __le32 dlen;
+
+        memcpy(&dlen, buf, LZO_LEN);
+        return le32_to_cpu(dlen);
+}
+
+static int lzo_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 = LZO_LEN;
+        tot_out = LZO_LEN;
+        pages[0] = out_page;
+        nr_pages = 1;
+        pg_bytes_left = PAGE_CACHE_SIZE - LZO_LEN;
+
+        /* compress at most one page of data each time */
+        in_len = min(len, PAGE_CACHE_SIZE);
+        while (tot_in < len) {
+                ret = lzo1x_1_compress(data_in, in_len, workspace->cbuf,
+                                       &out_len, workspace->mem);
+                if (ret != LZO_E_OK) {
+                        printk(KERN_DEBUG "btrfs deflate 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 += LZO_LEN;
+                out_offset += LZO_LEN;
+                pg_bytes_left -= LZO_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 < LZO_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 lzo_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;
+        char *data_in;
+        unsigned long page_bytes_left;
+        unsigned long page_in_index = 0;
+        unsigned long page_out_index = 0;
+        struct page *page_out;
+        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;
+        unsigned long start_byte;
+        unsigned long current_buf_start;
+        char *kaddr;
+
+        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;
+
+        data_in = kmap(pages_in[0]);
+        tot_len = read_compress_length(data_in);
+
+        tot_in = LZO_LEN;
+        in_offset = LZO_LEN;
+        tot_len = min_t(size_t, srclen, tot_len);
+        in_page_bytes_left = PAGE_CACHE_SIZE - LZO_LEN;
+
+        tot_out = 0;
+        page_out = bvec[0].bv_page;
+        page_bytes_left = PAGE_CACHE_SIZE;
+        pg_offset = 0;
+
+        while (tot_in < tot_len) {
+                in_len = read_compress_length(data_in + in_offset);
+                in_page_bytes_left -= LZO_LEN;
+                in_offset += LZO_LEN;
+                tot_in += LZO_LEN;
+
+                tot_in += in_len;
+                working_bytes = in_len;
+
+                /* fast path: avoid using the working buffer */
+                if (in_page_bytes_left >= in_len) {
+                        buf = data_in + in_offset;
+                        bytes = in_len;
+                        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 < LZO_LEN)
+                            || in_page_bytes_left == 0) {
+                                tot_in += in_page_bytes_left;
+
+                                if (working_bytes == 0 && tot_in >= tot_len)
+                                        break;
+
+                                kunmap(pages_in[page_in_index]);
+                                page_in_index++;
+                                if (page_in_index >= total_pages_in) {
+                                        ret = -1;
+                                        data_in = NULL;
+                                        goto done;
+                                }
+                                data_in = kmap(pages_in[page_in_index]);
+
+                                in_page_bytes_left = PAGE_CACHE_SIZE;
+                                in_offset = 0;
+                        }
+                }
+
+                out_len = lzo1x_worst_compress(PAGE_CACHE_SIZE);
+                ret = lzo1x_decompress_safe(buf, in_len, workspace->buf,
+                                            &out_len);
+                if (ret != LZO_E_OK) {
+                        printk(KERN_WARNING "btrfs decompress failed\n");
+                        ret = -1;
+                        break;
+                }
+
+                /*
+                 * buf start is the byte offset we're of the start of
+                 * our workspace buffer
+                 */
+                buf_start = tot_out;
+
+                /* tot_out is the last byte of the workspace buffer */
+                tot_out += out_len;
+
+                working_bytes = tot_out - buf_start;
+
+                /*
+                 * start_byte is the first byte of the page we're currently
+                 * copying into relative to the start of the compressed data.
+                 */
+                start_byte = page_offset(page_out) - disk_start;
+
+                if (working_bytes == 0) {
+                        /* we didn't make progress in this inflate
+                         * call, we're done
+                         */
+                        break;
+                }
+
+                /* we haven't yet hit data corresponding to this page */
+                if (tot_out <= start_byte)
+                        continue;
+
+                /*
+                 * the start of the data we care about is offset into
+                 * the middle of our working buffer
+                 */
+                if (tot_out > start_byte && buf_start < start_byte) {
+                        buf_offset = start_byte - buf_start;
+                        working_bytes -= buf_offset;
+                } else {
+                        buf_offset = 0;
+                }
+                current_buf_start = buf_start;
+
+                /* copy bytes from the working buffer into the pages */
+                while (working_bytes > 0) {
+                        bytes = min(PAGE_CACHE_SIZE - pg_offset,
+                                    PAGE_CACHE_SIZE - buf_offset);
+                        bytes = min(bytes, working_bytes);
+                        kaddr = kmap_atomic(page_out, KM_USER0);
+                        memcpy(kaddr + pg_offset, workspace->buf + buf_offset,
+                               bytes);
+                        kunmap_atomic(kaddr, KM_USER0);
+                        flush_dcache_page(page_out);
+
+                        pg_offset += bytes;
+                        page_bytes_left -= bytes;
+                        buf_offset += bytes;
+                        working_bytes -= bytes;
+                        current_buf_start += bytes;
+
+                        /* check if we need to pick another page */
+                        if (page_bytes_left == 0) {
+                                page_out_index++;
+                                if (page_out_index >= vcnt) {
+                                        ret = 0;
+                                        goto done;
+                                }
+
+                                page_out = bvec[page_out_index].bv_page;
+                                pg_offset = 0;
+                                page_bytes_left = PAGE_CACHE_SIZE;
+                                start_byte = page_offset(page_out) - disk_start;
+
+                                /*
+                                 * make sure our new page is covered by this
+                                 * working buffer
+                                 */
+                                if (tot_out <= start_byte)
+                                        break;
+
+                                /* the next page in the biovec might not
+                                 * be adjacent to the last page, but it
+                                 * might still be found inside this working
+                                 * buffer.  bump our offset pointer
+                                 */
+                                if (tot_out > start_byte &&
+                                    current_buf_start < start_byte) {
+                                        buf_offset = start_byte - buf_start;
+                                        working_bytes = tot_out - start_byte;
+                                        current_buf_start = buf_start +
+                                                buf_offset;
+                                }
+                        }
+                }
+        }
+done:
+        if (data_in)
+                kunmap(pages_in[page_in_index]);
+        return ret;
+}
+
+static int lzo_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 < LZO_LEN);
+
+        tot_len = read_compress_length(data_in);
+        data_in += LZO_LEN;
+
+        in_len = read_compress_length(data_in);
+        data_in += LZO_LEN;
+
+        out_len = PAGE_CACHE_SIZE;
+        ret = lzo1x_decompress_safe(data_in, in_len, workspace->buf, &out_len);
+        if (ret != LZO_E_OK) {
+                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_lzo_compress = {
+        .alloc_workspace        = lzo_alloc_workspace,
+        .free_workspace         = lzo_free_workspace,
+        .compress_pages         = lzo_compress_pages,
+        .decompress_biovec      = lzo_decompress_biovec,
+        .decompress             = lzo_decompress,
+};
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f348f2b93164..a1a76b2a61f9 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -168,6 +168,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                             strcmp(args[0].from, "zlib") == 0) {
                                 compress_type = "zlib";
                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
+                        } else if (strcmp(args[0].from, "lzo") == 0) {
+                                compress_type = "lzo";
+                                info->compress_type = BTRFS_COMPRESS_LZO;
                         } else {
                                 ret = -EINVAL;
                                 goto out;