d93435c3fb
Improvement idea by Marcin Jabrzyk. comp_algorithm_store() silently accepts any supplied algorithm name, because zram performs algorithm availability check later, during the device configuration phase in disksize_store() and emits the following error: "zram: Cannot initialise %s compressing backend" this error line is somewhat generic and, besides, can indicate a failed attempt to allocate compression backend's working buffers. add algorithm availability check to comp_algorithm_store(): echo lzz > /sys/block/zram0/comp_algorithm -bash: echo: write error: Invalid argument Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
70 lines
2 KiB
C
70 lines
2 KiB
C
/*
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* Copyright (C) 2014 Sergey Senozhatsky.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ZCOMP_H_
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#define _ZCOMP_H_
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#include <linux/mutex.h>
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struct zcomp_strm {
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/* compression/decompression buffer */
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void *buffer;
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/*
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* The private data of the compression stream, only compression
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* stream backend can touch this (e.g. compression algorithm
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* working memory)
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*/
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void *private;
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/* used in multi stream backend, protected by backend strm_lock */
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struct list_head list;
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};
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/* static compression backend */
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struct zcomp_backend {
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int (*compress)(const unsigned char *src, unsigned char *dst,
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size_t *dst_len, void *private);
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int (*decompress)(const unsigned char *src, size_t src_len,
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unsigned char *dst);
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void *(*create)(void);
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void (*destroy)(void *private);
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const char *name;
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};
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/* dynamic per-device compression frontend */
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struct zcomp {
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void *stream;
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struct zcomp_backend *backend;
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struct zcomp_strm *(*strm_find)(struct zcomp *comp);
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void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm);
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bool (*set_max_streams)(struct zcomp *comp, int num_strm);
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void (*destroy)(struct zcomp *comp);
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};
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ssize_t zcomp_available_show(const char *comp, char *buf);
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bool zcomp_available_algorithm(const char *comp);
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struct zcomp *zcomp_create(const char *comp, int max_strm);
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void zcomp_destroy(struct zcomp *comp);
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struct zcomp_strm *zcomp_strm_find(struct zcomp *comp);
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void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm);
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int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
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const unsigned char *src, size_t *dst_len);
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int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
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size_t src_len, unsigned char *dst);
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bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
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#endif /* _ZCOMP_H_ */
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