Messages in this thread | | | Date | Tue, 8 Oct 2013 23:25:42 +0900 | Subject | Re: [PATCH] Squashfs: Refactor decompressor interface and code | From | Minchan Kim <> |
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On Tue, Oct 8, 2013 at 11:14 AM, Phillip Lougher <phillip@squashfs.org.uk> wrote: > The decompressor interface and code was written from > the point of view of single-threaded operation. In doing > so it mixed a lot of single-threaded implementation specific > aspects into the decompressor code and elsewhere which makes it > difficult to seamlessly support multiple different decompressor > implementations. > > This patch does the following: > > 1. It removes compressor_options parsing from the decompressor > init() function. This allows the decompressor init() function > to be dynamically called to instantiate multiple decompressors, > without the compressor options needing to be read and parsed each > time. > > 2. It moves threading and all sleeping operations out of the > decompressors. In doing so, it makes the decompressors > non-blocking wrappers which only deal with interfacing with > the decompressor implementation. > > 3. It splits decompressor.[ch] into decompressor generic functions > in decompressor.[ch], and moves the single threaded > decompressor implementation into decompressor_single.c. > > The result of this patch is Squashfs should now be able to > support multiple decompressors by adding new decompressor_xxx.c > files with specialised implementations of the functions in > decompressor_single.c > > This has the following functions > > decompressor_create() > - Called at mount time to initialise internal decompressor state. > - An opaque pointer to the decompressor private state is returned (or error). > - The function is called with a pointer to the parsed and swapped comp_opts > structure returned by the new decompressor comp_opts() call. > > decompressor_destroy() > - Destroy all decompressor private state > - kfree the comp_opts buffer > > decompress() > - Select a decompressor or create a new decompressor > - Call using whatever locking scheme is necessary > > All decompressor implementation specific private state has been moved from the > squashfs_sb_info structure into the opaque private state returned by > decompressor_create(). This is deliberate, now all implementation specific > code has been moved to decompressor_xxx.c, no other code needs to/or should need > to access anything within it. > > Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Minchan Kim <minchan@kernel.org>
It's a really fantastic clean up. I will implement decompressor_multi.c after holiday. Thanks for your help!
-- Kind regards, Minchan Kim
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