Re: [PATCH] btrfs compression: merge inflate and deflate z_streams

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

On (07/01/14 16:44), David Sterba wrote:
> On Tue, Jul 01, 2014 at 12:32:10AM +0900, Sergey Senozhatsky wrote:
> > `struct workspace' used for zlib compression contains two zlib
> > z_stream-s: `def_strm' used in zlib_compress_pages(), and `inf_strm'
> > used in zlib_decompress/zlib_decompress_biovec(). None of these
> > functions use `inf_strm' and `def_strm' simultaniously, meaning that
> > for every compress/decompress operation we need only one z_stream
> > (out of two available).
> > 
> > `inf_strm' and `def_strm' are different in size of ->workspace. For
> > inflate stream we vmalloc() zlib_inflate_workspacesize() bytes, for
> > deflate stream - zlib_deflate_workspacesize() bytes. On my system zlib
> > returns the following workspace sizes, correspondingly: 42312 and 268104
> > (+ guard pages).
> > 
> > Keep only one `z_stream' in `struct workspace' and use it for both
> > compression and decompression. Hence, instead of vmalloc() of two
> > z_stream->worskpace-s, allocate only one of size:
> > 	max(zlib_deflate_workspacesize(), zlib_inflate_workspacesize())
> > 
> > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> 
> Reviewed-by: David Sterba <dsterba@suse.cz>
> 

Hello,

the patch does not apply against linux-next rc4-20140707 due to 130d5b415a091e.
unhappy hunk is:

+		if (workspace->strm.total_in > 8192 &&
+		    workspace->strm.total_in <
+		    workspace->strm.total_out) {
 			ret = -EIO;

now it should be:
+		if (workspace->strm.total_in > 8192 &&
+		    workspace->strm.total_in <
+		    workspace->strm.total_out) {
 			ret = -E2BIG;


I'll rebase and resend.

	-ss