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 <[email protected]>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 8bdd3dc..3e45252 100644
--- 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;
+}
