btrfs: Allow to add new compression algorithm
authorLi Zefan <lizf@cn.fujitsu.com>
Fri, 17 Dec 2010 06:21:50 +0000 (14:21 +0800)
committerLi Zefan <lizf@cn.fujitsu.com>
Wed, 22 Dec 2010 15:15:45 +0000 (23:15 +0800)
Make the code aware of compression type, instead of always assuming
zlib compression.

Also make the zlib workspace function as common code for all
compression types.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
15 files changed:
fs/btrfs/btrfs_inode.h
fs/btrfs/compression.c
fs/btrfs/compression.h
fs/btrfs/ctree.h
fs/btrfs/extent_io.c
fs/btrfs/extent_io.h
fs/btrfs/extent_map.c
fs/btrfs/extent_map.h
fs/btrfs/file.c
fs/btrfs/inode.c
fs/btrfs/ioctl.c
fs/btrfs/ordered-data.c
fs/btrfs/ordered-data.h
fs/btrfs/super.c
fs/btrfs/zlib.c

index 6ad63f17eca0acad289d0dbf972607933bf9fd50..ccc991c542df39ca152f53950aa98ec75aa1d7a9 100644 (file)
@@ -157,7 +157,7 @@ struct btrfs_inode {
        /*
         * always compress this one file
         */
-       unsigned force_compress:1;
+       unsigned force_compress:4;
 
        struct inode vfs_inode;
 };
index b50bc4bd5c5677e1f77926d30449e4bc32794e21..6638c9877720bfff8b6a20827f3ece370f330de0 100644 (file)
@@ -62,6 +62,9 @@ struct compressed_bio {
        /* number of bytes on disk */
        unsigned long compressed_len;
 
+       /* the compression algorithm for this bio */
+       int compress_type;
+
        /* number of compressed pages in the array */
        unsigned long nr_pages;
 
@@ -173,11 +176,12 @@ static void end_compressed_bio_read(struct bio *bio, int err)
        /* ok, we're the last bio for this extent, lets start
         * the decompression.
         */
-       ret = btrfs_zlib_decompress_biovec(cb->compressed_pages,
-                                       cb->start,
-                                       cb->orig_bio->bi_io_vec,
-                                       cb->orig_bio->bi_vcnt,
-                                       cb->compressed_len);
+       ret = btrfs_decompress_biovec(cb->compress_type,
+                                     cb->compressed_pages,
+                                     cb->start,
+                                     cb->orig_bio->bi_io_vec,
+                                     cb->orig_bio->bi_vcnt,
+                                     cb->compressed_len);
 csum_failed:
        if (ret)
                cb->errors = 1;
@@ -588,6 +592,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
        cb->len = uncompressed_len;
        cb->compressed_len = compressed_len;
+       cb->compress_type = extent_compress_type(bio_flags);
        cb->orig_bio = bio;
 
        nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
@@ -677,3 +682,224 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
        bio_put(comp_bio);
        return 0;
 }
+
+static struct list_head comp_idle_workspace[BTRFS_COMPRESS_TYPES];
+static spinlock_t comp_workspace_lock[BTRFS_COMPRESS_TYPES];
+static int comp_num_workspace[BTRFS_COMPRESS_TYPES];
+static atomic_t comp_alloc_workspace[BTRFS_COMPRESS_TYPES];
+static wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES];
+
+struct btrfs_compress_op *btrfs_compress_op[] = {
+       &btrfs_zlib_compress,
+};
+
+int __init btrfs_init_compress(void)
+{
+       int i;
+
+       for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
+               INIT_LIST_HEAD(&comp_idle_workspace[i]);
+               spin_lock_init(&comp_workspace_lock[i]);
+               atomic_set(&comp_alloc_workspace[i], 0);
+               init_waitqueue_head(&comp_workspace_wait[i]);
+       }
+       return 0;
+}
+
+/*
+ * this finds an available workspace or allocates a new one
+ * ERR_PTR is returned if things go bad.
+ */
+static struct list_head *find_workspace(int type)
+{
+       struct list_head *workspace;
+       int cpus = num_online_cpus();
+       int idx = type - 1;
+
+       struct list_head *idle_workspace        = &comp_idle_workspace[idx];
+       spinlock_t *workspace_lock              = &comp_workspace_lock[idx];
+       atomic_t *alloc_workspace               = &comp_alloc_workspace[idx];
+       wait_queue_head_t *workspace_wait       = &comp_workspace_wait[idx];
+       int *num_workspace                      = &comp_num_workspace[idx];
+again:
+       spin_lock(workspace_lock);
+       if (!list_empty(idle_workspace)) {
+               workspace = idle_workspace->next;
+               list_del(workspace);
+               (*num_workspace)--;
+               spin_unlock(workspace_lock);
+               return workspace;
+
+       }
+       if (atomic_read(alloc_workspace) > cpus) {
+               DEFINE_WAIT(wait);
+
+               spin_unlock(workspace_lock);
+               prepare_to_wait(workspace_wait, &wait, TASK_UNINTERRUPTIBLE);
+               if (atomic_read(alloc_workspace) > cpus && !*num_workspace)
+                       schedule();
+               finish_wait(workspace_wait, &wait);
+               goto again;
+       }
+       atomic_inc(alloc_workspace);
+       spin_unlock(workspace_lock);
+
+       workspace = btrfs_compress_op[idx]->alloc_workspace();
+       if (IS_ERR(workspace)) {
+               atomic_dec(alloc_workspace);
+               wake_up(workspace_wait);
+       }
+       return workspace;
+}
+
+/*
+ * put a workspace struct back on the list or free it if we have enough
+ * idle ones sitting around
+ */
+static void free_workspace(int type, struct list_head *workspace)
+{
+       int idx = type - 1;
+       struct list_head *idle_workspace        = &comp_idle_workspace[idx];
+       spinlock_t *workspace_lock              = &comp_workspace_lock[idx];
+       atomic_t *alloc_workspace               = &comp_alloc_workspace[idx];
+       wait_queue_head_t *workspace_wait       = &comp_workspace_wait[idx];
+       int *num_workspace                      = &comp_num_workspace[idx];
+
+       spin_lock(workspace_lock);
+       if (*num_workspace < num_online_cpus()) {
+               list_add_tail(workspace, idle_workspace);
+               (*num_workspace)++;
+               spin_unlock(workspace_lock);
+               goto wake;
+       }
+       spin_unlock(workspace_lock);
+
+       btrfs_compress_op[idx]->free_workspace(workspace);
+       atomic_dec(alloc_workspace);
+wake:
+       if (waitqueue_active(workspace_wait))
+               wake_up(workspace_wait);
+}
+
+/*
+ * cleanup function for module exit
+ */
+static void free_workspaces(void)
+{
+       struct list_head *workspace;
+       int i;
+
+       for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
+               while (!list_empty(&comp_idle_workspace[i])) {
+                       workspace = comp_idle_workspace[i].next;
+                       list_del(workspace);
+                       btrfs_compress_op[i]->free_workspace(workspace);
+                       atomic_dec(&comp_alloc_workspace[i]);
+               }
+       }
+}
+
+/*
+ * given an address space and start/len, compress the bytes.
+ *
+ * pages are allocated to hold the compressed result and stored
+ * in 'pages'
+ *
+ * out_pages is used to return the number of pages allocated.  There
+ * may be pages allocated even if we return an error
+ *
+ * total_in is used to return the number of bytes actually read.  It
+ * may be smaller then len if we had to exit early because we
+ * ran out of room in the pages array or because we cross the
+ * max_out threshold.
+ *
+ * total_out is used to return the total number of compressed bytes
+ *
+ * max_out tells us the max number of bytes that we're allowed to
+ * stuff into pages
+ */
+int btrfs_compress_pages(int type, 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 list_head *workspace;
+       int ret;
+
+       workspace = find_workspace(type);
+       if (IS_ERR(workspace))
+               return -1;
+
+       ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
+                                                     start, len, pages,
+                                                     nr_dest_pages, out_pages,
+                                                     total_in, total_out,
+                                                     max_out);
+       free_workspace(type, workspace);
+       return ret;
+}
+
+/*
+ * pages_in is an array of pages with compressed data.
+ *
+ * disk_start is the starting logical offset of this array in the file
+ *
+ * bvec is a bio_vec of pages from the file that we want to decompress into
+ *
+ * vcnt is the count of pages in the biovec
+ *
+ * srclen is the number of bytes in pages_in
+ *
+ * The basic idea is that we have a bio that was created by readpages.
+ * The pages in the bio are for the uncompressed data, and they may not
+ * be contiguous.  They all correspond to the range of bytes covered by
+ * the compressed extent.
+ */
+int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start,
+                           struct bio_vec *bvec, int vcnt, size_t srclen)
+{
+       struct list_head *workspace;
+       int ret;
+
+       workspace = find_workspace(type);
+       if (IS_ERR(workspace))
+               return -ENOMEM;
+
+       ret = btrfs_compress_op[type-1]->decompress_biovec(workspace, pages_in,
+                                                        disk_start,
+                                                        bvec, vcnt, srclen);
+       free_workspace(type, workspace);
+       return ret;
+}
+
+/*
+ * a less complex decompression routine.  Our compressed data fits in a
+ * single page, and we want to read a single page out of it.
+ * start_byte tells us the offset into the compressed data we're interested in
+ */
+int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
+                    unsigned long start_byte, size_t srclen, size_t destlen)
+{
+       struct list_head *workspace;
+       int ret;
+
+       workspace = find_workspace(type);
+       if (IS_ERR(workspace))
+               return -ENOMEM;
+
+       ret = btrfs_compress_op[type-1]->decompress(workspace, data_in,
+                                                 dest_page, start_byte,
+                                                 srclen, destlen);
+
+       free_workspace(type, workspace);
+       return ret;
+}
+
+void __exit btrfs_exit_compress(void)
+{
+       free_workspaces();
+}
index 421f5b4aa7151d4704256222de8e342e8899259d..9b5f2f365b79ee541641a584208e0bc26c72e6c5 100644 (file)
 #ifndef __BTRFS_COMPRESSION_
 #define __BTRFS_COMPRESSION_
 
-int btrfs_zlib_decompress(unsigned char *data_in,
-                         struct page *dest_page,
-                         unsigned long start_byte,
-                         size_t srclen, size_t destlen);
-int btrfs_zlib_compress_pages(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);
-int btrfs_zlib_decompress_biovec(struct page **pages_in,
-                             u64 disk_start,
-                             struct bio_vec *bvec,
-                             int vcnt,
-                             size_t srclen);
-void btrfs_zlib_exit(void);
+int btrfs_init_compress(void);
+void btrfs_exit_compress(void);
+
+int btrfs_compress_pages(int type, 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);
+int btrfs_decompress_biovec(int type, struct page **pages_in, u64 disk_start,
+                           struct bio_vec *bvec, int vcnt, size_t srclen);
+int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
+                    unsigned long start_byte, size_t srclen, size_t destlen);
+
 int btrfs_submit_compressed_write(struct inode *inode, u64 start,
                                  unsigned long len, u64 disk_start,
                                  unsigned long compressed_len,
@@ -44,4 +42,36 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
                                  unsigned long nr_pages);
 int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                                 int mirror_num, unsigned long bio_flags);
+
+struct btrfs_compress_op {
+       struct list_head *(*alloc_workspace)(void);
+
+       void (*free_workspace)(struct list_head *workspace);
+
+       int (*compress_pages)(struct list_head *workspace,
+                             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);
+
+       int (*decompress_biovec)(struct list_head *workspace,
+                                struct page **pages_in,
+                                u64 disk_start,
+                                struct bio_vec *bvec,
+                                int vcnt,
+                                size_t srclen);
+
+       int (*decompress)(struct list_head *workspace,
+                         unsigned char *data_in,
+                         struct page *dest_page,
+                         unsigned long start_byte,
+                         size_t srclen, size_t destlen);
+};
+
+extern struct btrfs_compress_op btrfs_zlib_compress;
+
 #endif
index af52f6d7a4d8ed8269f0cf835ab09c14d9a5c8a1..e06534438592182451f4521b9d4f756af32c7b3f 100644 (file)
@@ -551,9 +551,10 @@ struct btrfs_timespec {
 } __attribute__ ((__packed__));
 
 enum btrfs_compression_type {
-       BTRFS_COMPRESS_NONE = 0,
-       BTRFS_COMPRESS_ZLIB = 1,
-       BTRFS_COMPRESS_LAST = 2,
+       BTRFS_COMPRESS_NONE  = 0,
+       BTRFS_COMPRESS_ZLIB  = 1,
+       BTRFS_COMPRESS_TYPES = 1,
+       BTRFS_COMPRESS_LAST  = 2,
 };
 
 struct btrfs_inode_item {
@@ -895,7 +896,8 @@ struct btrfs_fs_info {
         */
        u64 last_trans_log_full_commit;
        u64 open_ioctl_trans;
-       unsigned long mount_opt;
+       unsigned long mount_opt:20;
+       unsigned long compress_type:4;
        u64 max_inline;
        u64 alloc_start;
        struct btrfs_transaction *running_transaction;
index 5e7a94d7da897d3e6af0476aac6dfd5f8d7a209e..f1d1981289599b561e01eeecd8b1f48c7e44df60 100644 (file)
@@ -2028,8 +2028,11 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                BUG_ON(extent_map_end(em) <= cur);
                BUG_ON(end < cur);
 
-               if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+               if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
                        this_bio_flag = EXTENT_BIO_COMPRESSED;
+                       extent_set_compress_type(&this_bio_flag,
+                                                em->compress_type);
+               }
 
                iosize = min(extent_map_end(em) - cur, end - cur + 1);
                cur_end = min(extent_map_end(em) - 1, end);
index 4183c8178f01a846f7da0f016f74db5402de12c7..7083cfafd061abf64f7b0c2252bd91324022b79a 100644 (file)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
 #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
 
-/* flags for bio submission */
+/*
+ * flags for bio submission. The high bits indicate the compression
+ * type for this bio
+ */
 #define EXTENT_BIO_COMPRESSED 1
+#define EXTENT_BIO_FLAG_SHIFT 16
 
 /* these are bit numbers for test/set bit */
 #define EXTENT_BUFFER_UPTODATE 0
@@ -135,6 +139,17 @@ struct extent_buffer {
        wait_queue_head_t lock_wq;
 };
 
+static inline void extent_set_compress_type(unsigned long *bio_flags,
+                                           int compress_type)
+{
+       *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
+}
+
+static inline int extent_compress_type(unsigned long bio_flags)
+{
+       return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
+}
+
 struct extent_map_tree;
 
 static inline struct extent_state *extent_state_next(struct extent_state *state)
index 23cb8da3ff6633dd83ba0b4cb435e8f742ad0632..b0e1fce12530b91e8bb1adc3dbc02640d537fa77 100644 (file)
@@ -3,6 +3,7 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/hardirq.h>
+#include "ctree.h"
 #include "extent_map.h"
 
 
@@ -54,6 +55,7 @@ struct extent_map *alloc_extent_map(gfp_t mask)
                return em;
        em->in_tree = 0;
        em->flags = 0;
+       em->compress_type = BTRFS_COMPRESS_NONE;
        atomic_set(&em->refs, 1);
        return em;
 }
index ab6d74b6e6477dcfb1bf65df494c5749cc8d80d9..28b44dbd1e3508c37bd30a1ef990fd071b1096d0 100644 (file)
@@ -26,7 +26,8 @@ struct extent_map {
        unsigned long flags;
        struct block_device *bdev;
        atomic_t refs;
-       int in_tree;
+       unsigned int in_tree:1;
+       unsigned int compress_type:4;
 };
 
 struct extent_map_tree {
index 66836d85763bbfd2dafe3821a1be30f173784fdc..05df688c96f442311482a87e5d966494ccc0049b 100644 (file)
@@ -224,6 +224,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
 
                        split->bdev = em->bdev;
                        split->flags = flags;
+                       split->compress_type = em->compress_type;
                        ret = add_extent_mapping(em_tree, split);
                        BUG_ON(ret);
                        free_extent_map(split);
@@ -238,6 +239,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                        split->len = em->start + em->len - (start + len);
                        split->bdev = em->bdev;
                        split->flags = flags;
+                       split->compress_type = em->compress_type;
 
                        if (compressed) {
                                split->block_len = em->block_len;
index 5f9194438f7c208b88427eaa42c24778300979e6..ba563b2a5d6cfdc533e8f6a859632d39c12ff22f 100644 (file)
@@ -122,10 +122,10 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
        size_t cur_size = size;
        size_t datasize;
        unsigned long offset;
-       int use_compress = 0;
+       int compress_type = BTRFS_COMPRESS_NONE;
 
        if (compressed_size && compressed_pages) {
-               use_compress = 1;
+               compress_type = root->fs_info->compress_type;
                cur_size = compressed_size;
        }
 
@@ -159,7 +159,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
        btrfs_set_file_extent_ram_bytes(leaf, ei, size);
        ptr = btrfs_file_extent_inline_start(ei);
 
-       if (use_compress) {
+       if (compress_type != BTRFS_COMPRESS_NONE) {
                struct page *cpage;
                int i = 0;
                while (compressed_size > 0) {
@@ -176,7 +176,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
                        compressed_size -= cur_size;
                }
                btrfs_set_file_extent_compression(leaf, ei,
-                                                 BTRFS_COMPRESS_ZLIB);
+                                                 compress_type);
        } else {
                page = find_get_page(inode->i_mapping,
                                     start >> PAGE_CACHE_SHIFT);
@@ -263,6 +263,7 @@ struct async_extent {
        u64 compressed_size;
        struct page **pages;
        unsigned long nr_pages;
+       int compress_type;
        struct list_head list;
 };
 
@@ -280,7 +281,8 @@ static noinline int add_async_extent(struct async_cow *cow,
                                     u64 start, u64 ram_size,
                                     u64 compressed_size,
                                     struct page **pages,
-                                    unsigned long nr_pages)
+                                    unsigned long nr_pages,
+                                    int compress_type)
 {
        struct async_extent *async_extent;
 
@@ -290,6 +292,7 @@ static noinline int add_async_extent(struct async_cow *cow,
        async_extent->compressed_size = compressed_size;
        async_extent->pages = pages;
        async_extent->nr_pages = nr_pages;
+       async_extent->compress_type = compress_type;
        list_add_tail(&async_extent->list, &cow->extents);
        return 0;
 }
@@ -332,6 +335,7 @@ static noinline int compress_file_range(struct inode *inode,
        unsigned long max_uncompressed = 128 * 1024;
        int i;
        int will_compress;
+       int compress_type = root->fs_info->compress_type;
 
        actual_end = min_t(u64, isize, end + 1);
 again:
@@ -381,12 +385,16 @@ again:
                WARN_ON(pages);
                pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
 
-               ret = btrfs_zlib_compress_pages(inode->i_mapping, start,
-                                               total_compressed, pages,
-                                               nr_pages, &nr_pages_ret,
-                                               &total_in,
-                                               &total_compressed,
-                                               max_compressed);
+               if (BTRFS_I(inode)->force_compress)
+                       compress_type = BTRFS_I(inode)->force_compress;
+
+               ret = btrfs_compress_pages(compress_type,
+                                          inode->i_mapping, start,
+                                          total_compressed, pages,
+                                          nr_pages, &nr_pages_ret,
+                                          &total_in,
+                                          &total_compressed,
+                                          max_compressed);
 
                if (!ret) {
                        unsigned long offset = total_compressed &
@@ -493,7 +501,8 @@ again:
                 * and will submit them to the elevator.
                 */
                add_async_extent(async_cow, start, num_bytes,
-                                total_compressed, pages, nr_pages_ret);
+                                total_compressed, pages, nr_pages_ret,
+                                compress_type);
 
                if (start + num_bytes < end) {
                        start += num_bytes;
@@ -515,7 +524,8 @@ cleanup_and_bail_uncompressed:
                        __set_page_dirty_nobuffers(locked_page);
                        /* unlocked later on in the async handlers */
                }
-               add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0);
+               add_async_extent(async_cow, start, end - start + 1,
+                                0, NULL, 0, BTRFS_COMPRESS_NONE);
                *num_added += 1;
        }
 
@@ -640,6 +650,7 @@ retry:
                em->block_start = ins.objectid;
                em->block_len = ins.offset;
                em->bdev = root->fs_info->fs_devices->latest_bdev;
+               em->compress_type = async_extent->compress_type;
                set_bit(EXTENT_FLAG_PINNED, &em->flags);
                set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
 
@@ -656,11 +667,13 @@ retry:
                                                async_extent->ram_size - 1, 0);
                }
 
-               ret = btrfs_add_ordered_extent(inode, async_extent->start,
-                                              ins.objectid,
-                                              async_extent->ram_size,
-                                              ins.offset,
-                                              BTRFS_ORDERED_COMPRESSED);
+               ret = btrfs_add_ordered_extent_compress(inode,
+                                               async_extent->start,
+                                               ins.objectid,
+                                               async_extent->ram_size,
+                                               ins.offset,
+                                               BTRFS_ORDERED_COMPRESSED,
+                                               async_extent->compress_type);
                BUG_ON(ret);
 
                /*
@@ -1670,7 +1683,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
        struct btrfs_ordered_extent *ordered_extent = NULL;
        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
        struct extent_state *cached_state = NULL;
-       int compressed = 0;
+       int compress_type = 0;
        int ret;
        bool nolock = false;
 
@@ -1711,9 +1724,9 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
        trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
        if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
-               compressed = 1;
+               compress_type = ordered_extent->compress_type;
        if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
-               BUG_ON(compressed);
+               BUG_ON(compress_type);
                ret = btrfs_mark_extent_written(trans, inode,
                                                ordered_extent->file_offset,
                                                ordered_extent->file_offset +
@@ -1727,7 +1740,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
                                                ordered_extent->disk_len,
                                                ordered_extent->len,
                                                ordered_extent->len,
-                                               compressed, 0, 0,
+                                               compress_type, 0, 0,
                                                BTRFS_FILE_EXTENT_REG);
                unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
                                   ordered_extent->file_offset,
@@ -1829,6 +1842,8 @@ static int btrfs_io_failed_hook(struct bio *failed_bio,
                if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
                        logical = em->block_start;
                        failrec->bio_flags = EXTENT_BIO_COMPRESSED;
+                       extent_set_compress_type(&failrec->bio_flags,
+                                                em->compress_type);
                }
                failrec->logical = logical;
                free_extent_map(em);
@@ -4930,8 +4945,10 @@ static noinline int uncompress_inline(struct btrfs_path *path,
        size_t max_size;
        unsigned long inline_size;
        unsigned long ptr;
+       int compress_type;
 
        WARN_ON(pg_offset != 0);
+       compress_type = btrfs_file_extent_compression(leaf, item);
        max_size = btrfs_file_extent_ram_bytes(leaf, item);
        inline_size = btrfs_file_extent_inline_item_len(leaf,
                                        btrfs_item_nr(leaf, path->slots[0]));
@@ -4941,8 +4958,8 @@ static noinline int uncompress_inline(struct btrfs_path *path,
        read_extent_buffer(leaf, tmp, ptr, inline_size);
 
        max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
-       ret = btrfs_zlib_decompress(tmp, page, extent_offset,
-                                   inline_size, max_size);
+       ret = btrfs_decompress(compress_type, tmp, page,
+                              extent_offset, inline_size, max_size);
        if (ret) {
                char *kaddr = kmap_atomic(page, KM_USER0);
                unsigned long copy_size = min_t(u64,
@@ -4984,7 +5001,7 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
        struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
        struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
        struct btrfs_trans_handle *trans = NULL;
-       int compressed;
+       int compress_type;
 
 again:
        read_lock(&em_tree->lock);
@@ -5043,7 +5060,7 @@ again:
 
        found_type = btrfs_file_extent_type(leaf, item);
        extent_start = found_key.offset;
-       compressed = btrfs_file_extent_compression(leaf, item);
+       compress_type = btrfs_file_extent_compression(leaf, item);
        if (found_type == BTRFS_FILE_EXTENT_REG ||
            found_type == BTRFS_FILE_EXTENT_PREALLOC) {
                extent_end = extent_start +
@@ -5089,8 +5106,9 @@ again:
                        em->block_start = EXTENT_MAP_HOLE;
                        goto insert;
                }
-               if (compressed) {
+               if (compress_type != BTRFS_COMPRESS_NONE) {
                        set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+                       em->compress_type = compress_type;
                        em->block_start = bytenr;
                        em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
                                                                         item);
@@ -5124,12 +5142,14 @@ again:
                em->len = (copy_size + root->sectorsize - 1) &
                        ~((u64)root->sectorsize - 1);
                em->orig_start = EXTENT_MAP_INLINE;
-               if (compressed)
+               if (compress_type) {
                        set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+                       em->compress_type = compress_type;
+               }
                ptr = btrfs_file_extent_inline_start(item) + extent_offset;
                if (create == 0 && !PageUptodate(page)) {
-                       if (btrfs_file_extent_compression(leaf, item) ==
-                           BTRFS_COMPRESS_ZLIB) {
+                       if (btrfs_file_extent_compression(leaf, item) !=
+                           BTRFS_COMPRESS_NONE) {
                                ret = uncompress_inline(path, inode, page,
                                                        pg_offset,
                                                        extent_offset, item);
@@ -6479,7 +6499,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
        ei->ordered_data_close = 0;
        ei->orphan_meta_reserved = 0;
        ei->dummy_inode = 0;
-       ei->force_compress = 0;
+       ei->force_compress = BTRFS_COMPRESS_NONE;
 
        inode = &ei->vfs_inode;
        extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
index f87552a1d7ea0beeb540aa59ddac3754242304cc..8cb86d4d763c90c544ef92c1f9db4cc7f5a1bc8e 100644 (file)
@@ -683,7 +683,7 @@ static int btrfs_defrag_file(struct file *file,
                total_read++;
                mutex_lock(&inode->i_mutex);
                if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
-                       BTRFS_I(inode)->force_compress = 1;
+                       BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_ZLIB;
 
                ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
                if (ret)
@@ -781,7 +781,7 @@ loop_unlock:
                atomic_dec(&root->fs_info->async_submit_draining);
 
                mutex_lock(&inode->i_mutex);
-               BTRFS_I(inode)->force_compress = 0;
+               BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
                mutex_unlock(&inode->i_mutex);
        }
 
index ae7737e352c90f7ede523c357f72a92d78c80676..2b61e1ddcd996cbefd5f0e67093c61a2e2f9d19f 100644 (file)
@@ -172,7 +172,7 @@ static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
  */
 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
                                      u64 start, u64 len, u64 disk_len,
-                                     int type, int dio)
+                                     int type, int dio, int compress_type)
 {
        struct btrfs_ordered_inode_tree *tree;
        struct rb_node *node;
@@ -189,6 +189,7 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
        entry->disk_len = disk_len;
        entry->bytes_left = len;
        entry->inode = inode;
+       entry->compress_type = compress_type;
        if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
                set_bit(type, &entry->flags);
 
@@ -220,14 +221,25 @@ int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
                             u64 start, u64 len, u64 disk_len, int type)
 {
        return __btrfs_add_ordered_extent(inode, file_offset, start, len,
-                                         disk_len, type, 0);
+                                         disk_len, type, 0,
+                                         BTRFS_COMPRESS_NONE);
 }
 
 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
                                 u64 start, u64 len, u64 disk_len, int type)
 {
        return __btrfs_add_ordered_extent(inode, file_offset, start, len,
-                                         disk_len, type, 1);
+                                         disk_len, type, 1,
+                                         BTRFS_COMPRESS_NONE);
+}
+
+int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
+                                     u64 start, u64 len, u64 disk_len,
+                                     int type, int compress_type)
+{
+       return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+                                         disk_len, type, 0,
+                                         compress_type);
 }
 
 /*
index 61dca83119ddf9a4994fbb107edccb93d3163487..ff1f69aa1883d979e64ba59cbc98fbed487c610e 100644 (file)
@@ -68,7 +68,7 @@ struct btrfs_ordered_sum {
 
 #define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
 
-#define BTRFS_ORDERED_COMPRESSED 3 /* writing a compressed extent */
+#define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
 
 #define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
 
@@ -93,6 +93,9 @@ struct btrfs_ordered_extent {
        /* flags (described above) */
        unsigned long flags;
 
+       /* compression algorithm */
+       int compress_type;
+
        /* reference count */
        atomic_t refs;
 
@@ -148,6 +151,9 @@ int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
                             u64 start, u64 len, u64 disk_len, int type);
 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
                                 u64 start, u64 len, u64 disk_len, int type);
+int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
+                                     u64 start, u64 len, u64 disk_len,
+                                     int type, int compress_type);
 int btrfs_add_ordered_sum(struct inode *inode,
                          struct btrfs_ordered_extent *entry,
                          struct btrfs_ordered_sum *sum);
index 61bd79abb805a29d2c9b7c0527bc2860c84c6b37..f348f2b93164a7ffeac7954a3cb4ae7b3d7007b7 100644 (file)
@@ -69,9 +69,9 @@ enum {
        Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
        Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
        Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
-       Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
-       Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_err,
-       Opt_user_subvol_rm_allowed,
+       Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
+       Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
+       Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -86,7 +86,9 @@ static match_table_t tokens = {
        {Opt_alloc_start, "alloc_start=%s"},
        {Opt_thread_pool, "thread_pool=%d"},
        {Opt_compress, "compress"},
+       {Opt_compress_type, "compress=%s"},
        {Opt_compress_force, "compress-force"},
+       {Opt_compress_force_type, "compress-force=%s"},
        {Opt_ssd, "ssd"},
        {Opt_ssd_spread, "ssd_spread"},
        {Opt_nossd, "nossd"},
@@ -112,6 +114,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
        char *p, *num, *orig;
        int intarg;
        int ret = 0;
+       char *compress_type;
+       bool compress_force = false;
 
        if (!options)
                return 0;
@@ -154,14 +158,29 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        btrfs_set_opt(info->mount_opt, NODATACOW);
                        btrfs_set_opt(info->mount_opt, NODATASUM);
                        break;
-               case Opt_compress:
-                       printk(KERN_INFO "btrfs: use compression\n");
-                       btrfs_set_opt(info->mount_opt, COMPRESS);
-                       break;
                case Opt_compress_force:
-                       printk(KERN_INFO "btrfs: forcing compression\n");
-                       btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+               case Opt_compress_force_type:
+                       compress_force = true;
+               case Opt_compress:
+               case Opt_compress_type:
+                       if (token == Opt_compress ||
+                           token == Opt_compress_force ||
+                           strcmp(args[0].from, "zlib") == 0) {
+                               compress_type = "zlib";
+                               info->compress_type = BTRFS_COMPRESS_ZLIB;
+                       } else {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+
                        btrfs_set_opt(info->mount_opt, COMPRESS);
+                       if (compress_force) {
+                               btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+                               pr_info("btrfs: force %s compression\n",
+                                       compress_type);
+                       } else
+                               pr_info("btrfs: use %s compression\n",
+                                       compress_type);
                        break;
                case Opt_ssd:
                        printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
@@ -898,10 +917,14 @@ static int __init init_btrfs_fs(void)
        if (err)
                return err;
 
-       err = btrfs_init_cachep();
+       err = btrfs_init_compress();
        if (err)
                goto free_sysfs;
 
+       err = btrfs_init_cachep();
+       if (err)
+               goto free_compress;
+
        err = extent_io_init();
        if (err)
                goto free_cachep;
@@ -929,6 +952,8 @@ free_extent_io:
        extent_io_exit();
 free_cachep:
        btrfs_destroy_cachep();
+free_compress:
+       btrfs_exit_compress();
 free_sysfs:
        btrfs_exit_sysfs();
        return err;
@@ -943,7 +968,7 @@ static void __exit exit_btrfs_fs(void)
        unregister_filesystem(&btrfs_fs_type);
        btrfs_exit_sysfs();
        btrfs_cleanup_fs_uuids();
-       btrfs_zlib_exit();
+       btrfs_exit_compress();
 }
 
 module_init(init_btrfs_fs)
index b01558661e3b80d69e83e70bc6b9c8d81929316c..9a3e693917f294a42010343b8c0a4f908bdb4ab5 100644 (file)
 #include <linux/bio.h>
 #include "compression.h"
 
-/* Plan: call deflate() with avail_in == *sourcelen,
-       avail_out = *dstlen - 12 and flush == Z_FINISH.
-       If it doesn't manage to finish, call it again with
-       avail_in == 0 and avail_out set to the remaining 12
-       bytes for it to clean up.
-   Q: Is 12 bytes sufficient?
-*/
-#define STREAM_END_SPACE 12
-
 struct workspace {
        z_stream inf_strm;
        z_stream def_strm;
@@ -48,155 +39,51 @@ struct workspace {
        struct list_head list;
 };
 
-static LIST_HEAD(idle_workspace);
-static DEFINE_SPINLOCK(workspace_lock);
-static unsigned long num_workspace;
-static atomic_t alloc_workspace = ATOMIC_INIT(0);
-static DECLARE_WAIT_QUEUE_HEAD(workspace_wait);
+static void zlib_free_workspace(struct list_head *ws)
+{
+       struct workspace *workspace = list_entry(ws, struct workspace, list);
 
-/*
- * this finds an available zlib workspace or allocates a new one
- * NULL or an ERR_PTR is returned if things go bad.
- */
-static struct workspace *find_zlib_workspace(void)
+       vfree(workspace->def_strm.workspace);
+       vfree(workspace->inf_strm.workspace);
+       kfree(workspace->buf);
+       kfree(workspace);
+}
+
+static struct list_head *zlib_alloc_workspace(void)
 {
        struct workspace *workspace;
-       int ret;
-       int cpus = num_online_cpus();
-
-again:
-       spin_lock(&workspace_lock);
-       if (!list_empty(&idle_workspace)) {
-               workspace = list_entry(idle_workspace.next, struct workspace,
-                                      list);
-               list_del(&workspace->list);
-               num_workspace--;
-               spin_unlock(&workspace_lock);
-               return workspace;
-
-       }
-       if (atomic_read(&alloc_workspace) > cpus) {
-               DEFINE_WAIT(wait);
-
-               spin_unlock(&workspace_lock);
-               prepare_to_wait(&workspace_wait, &wait, TASK_UNINTERRUPTIBLE);
-               if (atomic_read(&alloc_workspace) > cpus && !num_workspace)
-                       schedule();
-               finish_wait(&workspace_wait, &wait);
-               goto again;
-       }
-       atomic_inc(&alloc_workspace);
-       spin_unlock(&workspace_lock);
 
        workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
-       if (!workspace) {
-               ret = -ENOMEM;
-               goto fail;
-       }
+       if (!workspace)
+               return ERR_PTR(-ENOMEM);
 
        workspace->def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
-       if (!workspace->def_strm.workspace) {
-               ret = -ENOMEM;
-               goto fail;
-       }
        workspace->inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
-       if (!workspace->inf_strm.workspace) {
-               ret = -ENOMEM;
-               goto fail_inflate;
-       }
        workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS);
-       if (!workspace->buf) {
-               ret = -ENOMEM;
-               goto fail_kmalloc;
-       }
-       return workspace;
-
-fail_kmalloc:
-       vfree(workspace->inf_strm.workspace);
-fail_inflate:
-       vfree(workspace->def_strm.workspace);
-fail:
-       kfree(workspace);
-       atomic_dec(&alloc_workspace);
-       wake_up(&workspace_wait);
-       return ERR_PTR(ret);
-}
-
-/*
- * put a workspace struct back on the list or free it if we have enough
- * idle ones sitting around
- */
-static int free_workspace(struct workspace *workspace)
-{
-       spin_lock(&workspace_lock);
-       if (num_workspace < num_online_cpus()) {
-               list_add_tail(&workspace->list, &idle_workspace);
-               num_workspace++;
-               spin_unlock(&workspace_lock);
-               if (waitqueue_active(&workspace_wait))
-                       wake_up(&workspace_wait);
-               return 0;
-       }
-       spin_unlock(&workspace_lock);
-       vfree(workspace->def_strm.workspace);
-       vfree(workspace->inf_strm.workspace);
-       kfree(workspace->buf);
-       kfree(workspace);
+       if (!workspace->def_strm.workspace ||
+           !workspace->inf_strm.workspace || !workspace->buf)
+               goto fail;
 
-       atomic_dec(&alloc_workspace);
-       if (waitqueue_active(&workspace_wait))
-               wake_up(&workspace_wait);
-       return 0;
-}
+       INIT_LIST_HEAD(&workspace->list);
 
-/*
- * cleanup function for module exit
- */
-static void free_workspaces(void)
-{
-       struct workspace *workspace;
-       while (!list_empty(&idle_workspace)) {
-               workspace = list_entry(idle_workspace.next, struct workspace,
-                                      list);
-               list_del(&workspace->list);
-               vfree(workspace->def_strm.workspace);
-               vfree(workspace->inf_strm.workspace);
-               kfree(workspace->buf);
-               kfree(workspace);
-               atomic_dec(&alloc_workspace);
-       }
+       return &workspace->list;
+fail:
+       zlib_free_workspace(&workspace->list);
+       return ERR_PTR(-ENOMEM);
 }
 
-/*
- * given an address space and start/len, compress the bytes.
- *
- * pages are allocated to hold the compressed result and stored
- * in 'pages'
- *
- * out_pages is used to return the number of pages allocated.  There
- * may be pages allocated even if we return an error
- *
- * total_in is used to return the number of bytes actually read.  It
- * may be smaller then len if we had to exit early because we
- * ran out of room in the pages array or because we cross the
- * max_out threshold.
- *
- * total_out is used to return the total number of compressed bytes
- *
- * max_out tells us the max number of bytes that we're allowed to
- * stuff into pages
- */
-int btrfs_zlib_compress_pages(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)
+static int zlib_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;
-       struct workspace *workspace;
        char *data_in;
        char *cpage_out;
        int nr_pages = 0;
@@ -208,10 +95,6 @@ int btrfs_zlib_compress_pages(struct address_space *mapping,
        *total_out = 0;
        *total_in = 0;
 
-       workspace = find_zlib_workspace();
-       if (IS_ERR(workspace))
-               return -1;
-
        if (Z_OK != zlib_deflateInit(&workspace->def_strm, 3)) {
                printk(KERN_WARNING "deflateInit failed\n");
                ret = -1;
@@ -325,35 +208,18 @@ out:
                kunmap(in_page);
                page_cache_release(in_page);
        }
-       free_workspace(workspace);
        return ret;
 }
 
-/*
- * pages_in is an array of pages with compressed data.
- *
- * disk_start is the starting logical offset of this array in the file
- *
- * bvec is a bio_vec of pages from the file that we want to decompress into
- *
- * vcnt is the count of pages in the biovec
- *
- * srclen is the number of bytes in pages_in
- *
- * The basic idea is that we have a bio that was created by readpages.
- * The pages in the bio are for the uncompressed data, and they may not
- * be contiguous.  They all correspond to the range of bytes covered by
- * the compressed extent.
- */
-int btrfs_zlib_decompress_biovec(struct page **pages_in,
-                             u64 disk_start,
-                             struct bio_vec *bvec,
-                             int vcnt,
-                             size_t srclen)
+static int zlib_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;
        int wbits = MAX_WBITS;
-       struct workspace *workspace;
        char *data_in;
        size_t total_out = 0;
        unsigned long page_bytes_left;
@@ -371,10 +237,6 @@ int btrfs_zlib_decompress_biovec(struct page **pages_in,
        unsigned long current_buf_start;
        char *kaddr;
 
-       workspace = find_zlib_workspace();
-       if (IS_ERR(workspace))
-               return -ENOMEM;
-
        data_in = kmap(pages_in[page_in_index]);
        workspace->inf_strm.next_in = data_in;
        workspace->inf_strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE);
@@ -400,8 +262,7 @@ int btrfs_zlib_decompress_biovec(struct page **pages_in,
 
        if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
                printk(KERN_WARNING "inflateInit failed\n");
-               ret = -1;
-               goto out;
+               return -1;
        }
        while (workspace->inf_strm.total_in < srclen) {
                ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
@@ -527,35 +388,21 @@ done:
        zlib_inflateEnd(&workspace->inf_strm);
        if (data_in)
                kunmap(pages_in[page_in_index]);
-out:
-       free_workspace(workspace);
        return ret;
 }
 
-/*
- * a less complex decompression routine.  Our compressed data fits in a
- * single page, and we want to read a single page out of it.
- * start_byte tells us the offset into the compressed data we're interested in
- */
-int btrfs_zlib_decompress(unsigned char *data_in,
-                         struct page *dest_page,
-                         unsigned long start_byte,
-                         size_t srclen, size_t destlen)
+static int zlib_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);
        int ret = 0;
        int wbits = MAX_WBITS;
-       struct workspace *workspace;
        unsigned long bytes_left = destlen;
        unsigned long total_out = 0;
        char *kaddr;
 
-       if (destlen > PAGE_CACHE_SIZE)
-               return -ENOMEM;
-
-       workspace = find_zlib_workspace();
-       if (IS_ERR(workspace))
-               return -ENOMEM;
-
        workspace->inf_strm.next_in = data_in;
        workspace->inf_strm.avail_in = srclen;
        workspace->inf_strm.total_in = 0;
@@ -576,8 +423,7 @@ int btrfs_zlib_decompress(unsigned char *data_in,
 
        if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
                printk(KERN_WARNING "inflateInit failed\n");
-               ret = -1;
-               goto out;
+               return -1;
        }
 
        while (bytes_left > 0) {
@@ -627,12 +473,13 @@ next:
                ret = 0;
 
        zlib_inflateEnd(&workspace->inf_strm);
-out:
-       free_workspace(workspace);
        return ret;
 }
 
-void btrfs_zlib_exit(void)
-{
-    free_workspaces();
-}
+struct btrfs_compress_op btrfs_zlib_compress = {
+       .alloc_workspace        = zlib_alloc_workspace,
+       .free_workspace         = zlib_free_workspace,
+       .compress_pages         = zlib_compress_pages,
+       .decompress_biovec      = zlib_decompress_biovec,
+       .decompress             = zlib_decompress,
+};