compr.c

jffs2源代码基于2。6内核

        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:
        D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
                printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
        })

        spin_unlock(&jffs2_compressor_list_lock);

        return 0;
}

int jffs2_unregister_compressor(struct jffs2_compressor *comp)
{
        D2(struct jffs2_compressor *this;)

        D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));

        spin_lock(&jffs2_compressor_list_lock);

        if (comp->usecount) {
                spin_unlock(&jffs2_compressor_list_lock);
                printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
                return -1;
        }
        list_del(&comp->list);

        D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
                printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
        })
        spin_unlock(&jffs2_compressor_list_lock);
        return 0;
}

#ifdef CONFIG_JFFS2_PROC

#define JFFS2_STAT_BUF_SIZE 16000

char *jffs2_list_compressors(void)
{
        struct jffs2_compressor *this;
        char *buf, *act_buf;

        act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
        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 = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);

        act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\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);
        spin_lock(&jffs2_compressor_list_lock);
        list_for_each_entry(this, &jffs2_compressor_list, list) {
                act_buf += sprintf(act_buf,"%10s ",this->name);
                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");
        }
        spin_unlock(&jffs2_compressor_list_lock);

        return buf;
}

char *jffs2_get_compression_mode_name(void) 
{
        switch (jffs2_compression_mode) {
        case JFFS2_COMPR_MODE_NONE:
                return "none";
        case JFFS2_COMPR_MODE_PRIORITY:
                return "priority";
        case JFFS2_COMPR_MODE_SIZE:
                return "size";
        }
        return "unkown";
}

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;
        spin_lock(&jffs2_compressor_list_lock);
        list_for_each_entry(this, &jffs2_compressor_list, list) {
                if (!strcmp(this->name, name)) {
                        this->disabled = disabled;
                        spin_unlock(&jffs2_compressor_list_lock);
                        return 0;                        
                }
        }
        spin_unlock(&jffs2_compressor_list_lock);
        printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
        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;
        spin_lock(&jffs2_compressor_list_lock);
        list_for_each_entry(this, &jffs2_compressor_list, list) {
                if (!strcmp(this->name, name)) {
                        this->priority = priority;
                        comp = this;
                        goto reinsert;
                }
        }
        spin_unlock(&jffs2_compressor_list_lock);
        printk(KERN_WARNING "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);
                        spin_unlock(&jffs2_compressor_list_lock);
                        return 0;
                }
        }
        list_add_tail(&comp->list, &jffs2_compressor_list);
        spin_unlock(&jffs2_compressor_list_lock);
        return 0;
}

#endif

void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
{
        if (orig != comprbuf)
                kfree(comprbuf);
}

int jffs2_compressors_init(void) 
{
/* Registering compressors */
#ifdef CONFIG_JFFS2_ZLIB
        jffs2_zlib_init();
#endif
#ifdef CONFIG_JFFS2_RTIME
        jffs2_rtime_init();
#endif
#ifdef CONFIG_JFFS2_RUBIN
        jffs2_rubinmips_init();
        jffs2_dynrubin_init();
#endif
#ifdef CONFIG_JFFS2_LZARI
        jffs2_lzari_init();
#endif
#ifdef CONFIG_JFFS2_LZO
        jffs2_lzo_init();
#endif
/* Setting default compression mode */
#ifdef CONFIG_JFFS2_CMODE_NONE
        jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
        D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
#else
#ifdef CONFIG_JFFS2_CMODE_SIZE
        jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
        D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
#else
        D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
#endif
#endif
        return 0;
}

int jffs2_compressors_exit(void) 
{
/* Unregistering compressors */
#ifdef CONFIG_JFFS2_LZO
        jffs2_lzo_exit();
#endif
#ifdef CONFIG_JFFS2_LZARI
        jffs2_lzari_exit();
#endif
#ifdef CONFIG_JFFS2_RUBIN
        jffs2_dynrubin_exit();
        jffs2_rubinmips_exit();
#endif
#ifdef CONFIG_JFFS2_RTIME
        jffs2_rtime_exit();
#endif
#ifdef CONFIG_JFFS2_ZLIB
        jffs2_zlib_exit();
#endif
        return 0;
}