btrfs: allow to set compression level for zlib

Preliminary support for setting compression level for zlib, the
following works:

$ mount -o compess=zlib                 # default
$ mount -o compess=zlib0                # same
$ mount -o compess=zlib9                # level 9, slower sync, less data
$ mount -o compess=zlib1                # level 1, faster sync, more data
$ mount -o remount,compress=zlib3	# level set by remount

The compress-force works the same as compress'.  The level is visible in
the same format in /proc/mounts. Level set via file property does not
work yet.

Required patch: "btrfs: prepare for extensions in compression options"

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 8bdd3dc..3e45252 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -884,6 +884,11 @@ static void free_workspaces(void)
  * Given an address space and start and length, compress the bytes into @pages
  * that are allocated on demand.
  *
+ * @type_level is encoded algorithm and level, where level 0 means whatever
+ * default the algorithm chooses and is opaque here;
+ * - compression algo are 0-3
+ * - the level are bits 4-7
+ *
  * @out_pages is an in/out parameter, holds maximum number of pages to allocate
  * and returns number of actually allocated pages
  *
@@ -898,7 +903,7 @@ static void free_workspaces(void)
  * @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,
+int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
                         u64 start, struct page **pages,
                         unsigned long *out_pages,
                         unsigned long *total_in,
@@ -906,9 +911,11 @@ int btrfs_compress_pages(int type, struct address_space *mapping,
 {
        struct list_head *workspace;
        int ret;
+       int type = type_level & 0xF;
 
        workspace = find_workspace(type);
 
+       btrfs_compress_op[type - 1]->set_level(workspace, type_level);
        ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
                                                      start, pages,
                                                      out_pages,
@@ -1098,3 +1105,14 @@ int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
 
        return ret;
 }
+
+unsigned int btrfs_compress_str2level(const char *str)
+{
+       if (strncmp(str, "zlib", 4) != 0)
+               return 0;
+
+       if ('1' <= str[4] && str[4] <= '9' )
+               return str[4] - '0';
+
+       return 0;
+}

diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index d2781ff..da20755 100644 (file)
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -76,7 +76,7 @@ struct compressed_bio {
 void btrfs_init_compress(void);
 void btrfs_exit_compress(void);
 
-int btrfs_compress_pages(int type, struct address_space *mapping,
+int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
                         u64 start, struct page **pages,
                         unsigned long *out_pages,
                         unsigned long *total_in,
@@ -95,6 +95,8 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                                 int mirror_num, unsigned long bio_flags);
 
+unsigned btrfs_compress_str2level(const char *str);
+
 enum btrfs_compression_type {
        BTRFS_COMPRESS_NONE  = 0,
        BTRFS_COMPRESS_ZLIB  = 1,
@@ -124,6 +126,8 @@ struct btrfs_compress_op {
                          struct page *dest_page,
                          unsigned long start_byte,
                          size_t srclen, size_t destlen);
+
+       void (*set_level)(struct list_head *ws, unsigned int type);
 };
 
 extern const struct btrfs_compress_op btrfs_zlib_compress;

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7bda842..2c02d95 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -790,6 +790,7 @@ struct btrfs_fs_info {
         */
        unsigned long pending_changes;
        unsigned long compress_type:4;
+       unsigned int compress_level;
        int commit_interval;
        /*
         * It is a suggestive number, the read side is safe even it gets a

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f2787ca..3f1b53f 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -539,7 +539,10 @@ again:
                 */
                extent_range_clear_dirty_for_io(inode, start, end);
                redirty = 1;
-               ret = btrfs_compress_pages(compress_type,
+
+               /* Compression level is applied here and only here */
+               ret = btrfs_compress_pages(
+                       compress_type | (fs_info->compress_level << 4),
                                           inode->i_mapping, start,
                                           pages,
                                           &nr_pages,

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index d433e75..6c7f18c 100644 (file)
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -430,10 +430,15 @@ out:
        return ret;
 }
 
+static void lzo_set_level(struct list_head *ws, unsigned int type)
+{
+}
+
 const struct btrfs_compress_op btrfs_lzo_compress = {
        .alloc_workspace        = lzo_alloc_workspace,
        .free_workspace         = lzo_free_workspace,
        .compress_pages         = lzo_compress_pages,
        .decompress_bio         = lzo_decompress_bio,
        .decompress             = lzo_decompress,
+       .set_level              = lzo_set_level,
 };

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4fb7eef..57f3f96 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -508,6 +508,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
                            strncmp(args[0].from, "zlib", 4) == 0) {
                                compress_type = "zlib";
                                info->compress_type = BTRFS_COMPRESS_ZLIB;
+                               info->compress_level =
+                                       btrfs_compress_str2level(args[0].from);
                                btrfs_set_opt(info->mount_opt, COMPRESS);
                                btrfs_clear_opt(info->mount_opt, NODATACOW);
                                btrfs_clear_opt(info->mount_opt, NODATASUM);
@@ -555,9 +557,9 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
                              compress_force != saved_compress_force)) ||
                            (!btrfs_test_opt(info, COMPRESS) &&
                             no_compress == 1)) {
-                               btrfs_info(info, "%s %s compression",
+                               btrfs_info(info, "%s %s compression, level %d",
                                           (compress_force) ? "force" : "use",
-                                          compress_type);
+                                          compress_type, info->compress_level);
                        }
                        compress_force = false;
                        break;
@@ -1258,6 +1260,8 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
                        seq_printf(seq, ",compress-force=%s", compress_type);
                else
                        seq_printf(seq, ",compress=%s", compress_type);
+               if (info->compress_level)
+                       seq_printf(seq, "%d", info->compress_level);
        }
        if (btrfs_test_opt(info, NOSSD))
                seq_puts(seq, ",nossd");

diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index c248f92..2b52950 100644 (file)
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -37,6 +37,7 @@ struct workspace {
        z_stream strm;
        char *buf;
        struct list_head list;
+       int level;
 };
 
 static void zlib_free_workspace(struct list_head *ws)
@@ -96,7 +97,7 @@ static int zlib_compress_pages(struct list_head *ws,
        *total_out = 0;
        *total_in = 0;
 
-       if (Z_OK != zlib_deflateInit(&workspace->strm, 3)) {
+       if (Z_OK != zlib_deflateInit(&workspace->strm, workspace->level)) {
                pr_warn("BTRFS: deflateInit failed\n");
                ret = -EIO;
                goto out;
@@ -402,10 +403,22 @@ next:
        return ret;
 }
 
+static void zlib_set_level(struct list_head *ws, unsigned int type)
+{
+       struct workspace *workspace = list_entry(ws, struct workspace, list);
+       unsigned level = (type & 0xF0) >> 4;
+
+       if (level > 9)
+               level = 9;
+
+       workspace->level = level > 0 ? level : 3;
+}
+
 const struct btrfs_compress_op btrfs_zlib_compress = {
        .alloc_workspace        = zlib_alloc_workspace,
        .free_workspace         = zlib_free_workspace,
        .compress_pages         = zlib_compress_pages,
        .decompress_bio         = zlib_decompress_bio,
        .decompress             = zlib_decompress,
+       .set_level              = zlib_set_level,
 };

diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 607ce47..17f2dd8 100644 (file)
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -423,10 +423,15 @@ finish:
        return ret;
 }
 
+static void zstd_set_level(struct list_head *ws, unsigned int type)
+{
+}
+
 const struct btrfs_compress_op btrfs_zstd_compress = {
        .alloc_workspace = zstd_alloc_workspace,
        .free_workspace = zstd_free_workspace,
        .compress_pages = zstd_compress_pages,
        .decompress_bio = zstd_decompress_bio,
        .decompress = zstd_decompress,
+       .set_level = zstd_set_level,
 };