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-rw-r--r--compr.c489
1 files changed, 489 insertions, 0 deletions
diff --git a/compr.c b/compr.c
new file mode 100644
index 0000000..4f7087a
--- /dev/null
+++ b/compr.c
@@ -0,0 +1,489 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
+ * University of Szeged, Hungary
+ *
+ * For licensing information, see the file 'LICENCE' in this directory
+ * in the jffs2 directory.
+ *
+ * $Id: compr.c,v 1.9 2005/11/07 11:15:09 gleixner Exp $
+ *
+ */
+
+#include "compr.h"
+#include <string.h>
+#include <stdlib.h>
+#include <linux/jffs2.h>
+
+extern int page_size;
+
+/* LIST IMPLEMENTATION (from linux/list.h) */
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct list_head name = LIST_HEAD_INIT(name)
+
+static inline void __list_add(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next)
+{
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head, head->next);
+}
+
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head->prev, head);
+}
+
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+static inline void list_del(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ entry->next = (void *) 0;
+ entry->prev = (void *) 0;
+}
+
+#define list_entry(ptr, type, member) \
+ ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+#define list_for_each_entry(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
+
+
+/* Available compressors are on this list */
+static LIST_HEAD(jffs2_compressor_list);
+
+/* Actual compression mode */
+static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
+
+void jffs2_set_compression_mode(int mode)
+{
+ jffs2_compression_mode = mode;
+}
+
+int jffs2_get_compression_mode(void)
+{
+ return jffs2_compression_mode;
+}
+
+/* Statistics for blocks stored without compression */
+static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
+
+/* Compression test stuffs */
+
+static int jffs2_compression_check = 0;
+
+static unsigned char *jffs2_compression_check_buf = NULL;
+
+void jffs2_compression_check_set(int yesno)
+{
+ jffs2_compression_check = yesno;
+}
+
+int jffs2_compression_check_get(void)
+{
+ return jffs2_compression_check;
+}
+
+static int jffs2_error_cnt = 0;
+
+int jffs2_compression_check_errorcnt_get(void)
+{
+ return jffs2_error_cnt;
+}
+
+#define JFFS2_BUFFER_FILL 0x55
+
+/* Called before compression (if compression_check is setted) to prepare
+ the buffer for buffer overflow test */
+static void jffs2_decompression_test_prepare(unsigned char *buf, int size)
+{
+ memset(buf,JFFS2_BUFFER_FILL,size+1);
+}
+
+/* Called after compression (if compression_check is setted) to test the result */
+static void jffs2_decompression_test(struct jffs2_compressor *compr,
+ unsigned char *data_in, unsigned char *output_buf,
+ uint32_t cdatalen, uint32_t datalen, uint32_t buf_size)
+{
+ uint32_t i;
+
+ /* buffer overflow test */
+ for (i=buf_size;i>cdatalen;i--) {
+ if (output_buf[i]!=JFFS2_BUFFER_FILL) {
+ fprintf(stderr,"COMPR_ERROR: buffer overflow at %s. "
+ "(bs=%d csize=%d b[%d]=%d)\n", compr->name,
+ buf_size, cdatalen, i, (int)(output_buf[i]));
+ jffs2_error_cnt++;
+ return;
+ }
+ }
+ /* allocing temporary buffer for decompression */
+ if (!jffs2_compression_check_buf) {
+ jffs2_compression_check_buf = malloc(page_size);
+ if (!jffs2_compression_check_buf) {
+ fprintf(stderr,"No memory for buffer allocation. Compression check disabled.\n");
+ jffs2_compression_check = 0;
+ return;
+ }
+ }
+ /* decompressing */
+ if (!compr->decompress) {
+ fprintf(stderr,"JFFS2 compression check: there is no decompress function at %s.\n", compr->name);
+ jffs2_error_cnt++;
+ return;
+ }
+ if (compr->decompress(output_buf,jffs2_compression_check_buf,cdatalen,datalen,NULL)) {
+ fprintf(stderr,"JFFS2 compression check: decompression failed at %s.\n", compr->name);
+ jffs2_error_cnt++;
+ }
+ /* validate decompression */
+ else {
+ for (i=0;i<datalen;i++) {
+ if (data_in[i]!=jffs2_compression_check_buf[i]) {
+ fprintf(stderr,"JFFS2 compression check: data mismatch at %s (pos %d).\n", compr->name, i);
+ jffs2_error_cnt++;
+ break;
+ }
+ }
+ }
+}
+
+/* jffs2_compress:
+ * @data: Pointer to uncompressed data
+ * @cdata: Pointer to returned pointer to buffer for compressed data
+ * @datalen: On entry, holds the amount of data available for compression.
+ * On exit, expected to hold the amount of data actually compressed.
+ * @cdatalen: On entry, holds the amount of space available for compressed
+ * data. On exit, expected to hold the actual size of the compressed
+ * data.
+ *
+ * Returns: Lower byte to be stored with data indicating compression type used.
+ * Zero is used to show that the data could not be compressed - the
+ * compressed version was actually larger than the original.
+ * Upper byte will be used later. (soon)
+ *
+ * If the cdata buffer isn't large enough to hold all the uncompressed data,
+ * jffs2_compress should compress as much as will fit, and should set
+ * *datalen accordingly to show the amount of data which were compressed.
+ */
+uint16_t jffs2_compress( unsigned char *data_in, unsigned char **cpage_out,
+ uint32_t *datalen, uint32_t *cdatalen)
+{
+ int ret = JFFS2_COMPR_NONE;
+ int compr_ret;
+ struct jffs2_compressor *this, *best=NULL;
+ unsigned char *output_buf = NULL, *tmp_buf;
+ uint32_t orig_slen, orig_dlen;
+ uint32_t best_slen=0, best_dlen=0;
+
+ switch (jffs2_compression_mode) {
+ case JFFS2_COMPR_MODE_NONE:
+ break;
+ case JFFS2_COMPR_MODE_PRIORITY:
+ orig_slen = *datalen;
+ orig_dlen = *cdatalen;
+ output_buf = malloc(orig_dlen+jffs2_compression_check);
+ if (!output_buf) {
+ fprintf(stderr,"mkfs.jffs2: No memory for compressor allocation. Compression failed.\n");
+ goto out;
+ }
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ /* Skip decompress-only backwards-compatibility and disabled modules */
+ if ((!this->compress)||(this->disabled))
+ continue;
+
+ this->usecount++;
+
+ if (jffs2_compression_check) /*preparing output buffer for testing buffer overflow */
+ jffs2_decompression_test_prepare(output_buf, orig_dlen);
+
+ *datalen = orig_slen;
+ *cdatalen = orig_dlen;
+ compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL);
+ this->usecount--;
+ if (!compr_ret) {
+ ret = this->compr;
+ this->stat_compr_blocks++;
+ this->stat_compr_orig_size += *datalen;
+ this->stat_compr_new_size += *cdatalen;
+ if (jffs2_compression_check)
+ jffs2_decompression_test(this, data_in, output_buf, *cdatalen, *datalen, orig_dlen);
+ break;
+ }
+ }
+ if (ret == JFFS2_COMPR_NONE) free(output_buf);
+ break;
+ case JFFS2_COMPR_MODE_SIZE:
+ orig_slen = *datalen;
+ orig_dlen = *cdatalen;
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ /* Skip decompress-only backwards-compatibility and disabled modules */
+ if ((!this->compress)||(this->disabled))
+ continue;
+ /* Allocating memory for output buffer if necessary */
+ if ((this->compr_buf_size<orig_dlen+jffs2_compression_check)&&(this->compr_buf)) {
+ free(this->compr_buf);
+ this->compr_buf_size=0;
+ this->compr_buf=NULL;
+ }
+ if (!this->compr_buf) {
+ tmp_buf = malloc(orig_dlen+jffs2_compression_check);
+ if (!tmp_buf) {
+ fprintf(stderr,"mkfs.jffs2: No memory for compressor allocation. (%d bytes)\n",orig_dlen);
+ continue;
+ }
+ else {
+ this->compr_buf = tmp_buf;
+ this->compr_buf_size = orig_dlen;
+ }
+ }
+ this->usecount++;
+ if (jffs2_compression_check) /*preparing output buffer for testing buffer overflow */
+ jffs2_decompression_test_prepare(this->compr_buf,this->compr_buf_size);
+ *datalen = orig_slen;
+ *cdatalen = orig_dlen;
+ compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL);
+ this->usecount--;
+ if (!compr_ret) {
+ if (jffs2_compression_check)
+ jffs2_decompression_test(this, data_in, this->compr_buf, *cdatalen, *datalen, this->compr_buf_size);
+ if ((!best_dlen)||(best_dlen>*cdatalen)) {
+ best_dlen = *cdatalen;
+ best_slen = *datalen;
+ best = this;
+ }
+ }
+ }
+ if (best_dlen) {
+ *cdatalen = best_dlen;
+ *datalen = best_slen;
+ output_buf = best->compr_buf;
+ best->compr_buf = NULL;
+ best->compr_buf_size = 0;
+ best->stat_compr_blocks++;
+ best->stat_compr_orig_size += best_slen;
+ best->stat_compr_new_size += best_dlen;
+ ret = best->compr;
+ }
+ break;
+ default:
+ fprintf(stderr,"mkfs.jffs2: unknow compression mode.\n");
+ }
+ out:
+ if (ret == JFFS2_COMPR_NONE) {
+ *cpage_out = data_in;
+ *datalen = *cdatalen;
+ none_stat_compr_blocks++;
+ none_stat_compr_size += *datalen;
+ }
+ else {
+ *cpage_out = output_buf;
+ }
+ return ret;
+}
+
+
+int jffs2_register_compressor(struct jffs2_compressor *comp)
+{
+ struct jffs2_compressor *this;
+
+ if (!comp->name) {
+ fprintf(stderr,"NULL compressor name at registering JFFS2 compressor. Failed.\n");
+ return -1;
+ }
+ comp->compr_buf_size=0;
+ comp->compr_buf=NULL;
+ comp->usecount=0;
+ comp->stat_compr_orig_size=0;
+ comp->stat_compr_new_size=0;
+ comp->stat_compr_blocks=0;
+ comp->stat_decompr_blocks=0;
+
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ if (this->priority < comp->priority) {
+ list_add(&comp->list, this->list.prev);
+ goto out;
+ }
+ }
+ list_add_tail(&comp->list, &jffs2_compressor_list);
+out:
+ return 0;
+}
+
+int jffs2_unregister_compressor(struct jffs2_compressor *comp)
+{
+
+ if (comp->usecount) {
+ fprintf(stderr,"mkfs.jffs2: Compressor modul is in use. Unregister failed.\n");
+ return -1;
+ }
+ list_del(&comp->list);
+
+ return 0;
+}
+
+#define JFFS2_STAT_BUF_SIZE 16000
+
+char *jffs2_list_compressors(void)
+{
+ struct jffs2_compressor *this;
+ char *buf, *act_buf;
+
+ act_buf = buf = malloc(JFFS2_STAT_BUF_SIZE);
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority);
+ if ((this->disabled)||(!this->compress))
+ act_buf += sprintf(act_buf,"disabled");
+ else
+ act_buf += sprintf(act_buf,"enabled");
+ act_buf += sprintf(act_buf,"\n");
+ }
+ return buf;
+}
+
+char *jffs2_stats(void)
+{
+ struct jffs2_compressor *this;
+ char *buf, *act_buf;
+
+ act_buf = buf = malloc(JFFS2_STAT_BUF_SIZE);
+
+ act_buf += sprintf(act_buf,"Compression mode: ");
+ switch (jffs2_compression_mode) {
+ case JFFS2_COMPR_MODE_NONE:
+ act_buf += sprintf(act_buf,"none");
+ break;
+ case JFFS2_COMPR_MODE_PRIORITY:
+ act_buf += sprintf(act_buf,"priority");
+ break;
+ case JFFS2_COMPR_MODE_SIZE:
+ act_buf += sprintf(act_buf,"size");
+ break;
+ default:
+ act_buf += sprintf(act_buf,"unkown");
+ break;
+ }
+ act_buf += sprintf(act_buf,"\nCompressors:\n");
+ act_buf += sprintf(act_buf,"%10s ","none");
+ act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks,
+ none_stat_compr_size, none_stat_decompr_blocks);
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ act_buf += sprintf(act_buf,"%10s (prio:%d) ",this->name,this->priority);
+ if ((this->disabled)||(!this->compress))
+ act_buf += sprintf(act_buf,"- ");
+ else
+ act_buf += sprintf(act_buf,"+ ");
+ act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks,
+ this->stat_compr_new_size, this->stat_compr_orig_size,
+ this->stat_decompr_blocks);
+ act_buf += sprintf(act_buf,"\n");
+ }
+ return buf;
+}
+
+int jffs2_set_compression_mode_name(const char *name)
+{
+ if (!strcmp("none",name)) {
+ jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
+ return 0;
+ }
+ if (!strcmp("priority",name)) {
+ jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
+ return 0;
+ }
+ if (!strcmp("size",name)) {
+ jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
+ return 0;
+ }
+ return 1;
+}
+
+static int jffs2_compressor_Xable(const char *name, int disabled)
+{
+ struct jffs2_compressor *this;
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ if (!strcmp(this->name, name)) {
+ this->disabled = disabled;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+int jffs2_enable_compressor_name(const char *name)
+{
+ return jffs2_compressor_Xable(name, 0);
+}
+
+int jffs2_disable_compressor_name(const char *name)
+{
+ return jffs2_compressor_Xable(name, 1);
+}
+
+int jffs2_set_compressor_priority(const char *name, int priority)
+{
+ struct jffs2_compressor *this,*comp;
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ if (!strcmp(this->name, name)) {
+ this->priority = priority;
+ comp = this;
+ goto reinsert;
+ }
+ }
+ fprintf(stderr,"mkfs.jffs2: compressor %s not found.\n",name);
+ return 1;
+reinsert:
+ /* list is sorted in the order of priority, so if
+ we change it we have to reinsert it into the
+ good place */
+ list_del(&comp->list);
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ if (this->priority < comp->priority) {
+ list_add(&comp->list, this->list.prev);
+ return 0;
+ }
+ }
+ list_add_tail(&comp->list, &jffs2_compressor_list);
+ return 0;
+}
+
+
+int jffs2_compressors_init(void)
+{
+#ifdef CONFIG_JFFS2_ZLIB
+ jffs2_zlib_init();
+#endif
+#ifdef CONFIG_JFFS2_RTIME
+ jffs2_rtime_init();
+#endif
+ return 0;
+}
+
+int jffs2_compressors_exit(void)
+{
+#ifdef CONFIG_JFFS2_RTIME
+ jffs2_rtime_exit();
+#endif
+#ifdef CONFIG_JFFS2_ZLIB
+ jffs2_zlib_exit();
+#endif
+ return 0;
+}