Initial commit

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;
+}