Commit f51d2b59 authored by David Sterba's avatar David Sterba
Browse files

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: default avatarDavid Sterba <dsterba@suse.com>
parent d4417e22

fs/btrfs/compression.c

+19 −1
Original line number Diff line number Diff line
@@ -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;

}

fs/btrfs/compression.h

+5 −1
Original line number Diff line number Diff line
@@ -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;

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -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

fs/btrfs/inode.c

+4 −1
Original line number Diff line number Diff line
@@ -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,

fs/btrfs/lzo.c

+5 −0
Original line number Diff line number Diff line
@@ -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,

};

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