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-rw-r--r--fs/jffs2/compr.c469
1 files changed, 469 insertions, 0 deletions
diff --git a/fs/jffs2/compr.c b/fs/jffs2/compr.c
new file mode 100644
index 000000000000..af922a9618ac
--- /dev/null
+++ b/fs/jffs2/compr.c
@@ -0,0 +1,469 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001-2003 Red Hat, Inc.
+ * Created by Arjan van de Ven <arjanv@redhat.com>
+ *
+ * Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
+ * University of Szeged, Hungary
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ * $Id: compr.c,v 1.42 2004/08/07 21:56:08 dwmw2 Exp $
+ *
+ */
+
+#include "compr.h"
+
+static DEFINE_SPINLOCK(jffs2_compressor_list_lock);
+
+/* Available compressors are on this list */
+static LIST_HEAD(jffs2_compressor_list);
+
+/* Actual compression mode */
+static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
+
+/* Statistics for blocks stored without compression */
+static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
+
+/* 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(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+ 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:
+ output_buf = kmalloc(*cdatalen,GFP_KERNEL);
+ if (!output_buf) {
+ printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
+ goto out;
+ }
+ orig_slen = *datalen;
+ orig_dlen = *cdatalen;
+ spin_lock(&jffs2_compressor_list_lock);
+ 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++;
+ spin_unlock(&jffs2_compressor_list_lock);
+ *datalen = orig_slen;
+ *cdatalen = orig_dlen;
+ compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL);
+ spin_lock(&jffs2_compressor_list_lock);
+ this->usecount--;
+ if (!compr_ret) {
+ ret = this->compr;
+ this->stat_compr_blocks++;
+ this->stat_compr_orig_size += *datalen;
+ this->stat_compr_new_size += *cdatalen;
+ break;
+ }
+ }
+ spin_unlock(&jffs2_compressor_list_lock);
+ if (ret == JFFS2_COMPR_NONE) kfree(output_buf);
+ break;
+ case JFFS2_COMPR_MODE_SIZE:
+ orig_slen = *datalen;
+ orig_dlen = *cdatalen;
+ spin_lock(&jffs2_compressor_list_lock);
+ 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)&&(this->compr_buf)) {
+ spin_unlock(&jffs2_compressor_list_lock);
+ kfree(this->compr_buf);
+ spin_lock(&jffs2_compressor_list_lock);
+ this->compr_buf_size=0;
+ this->compr_buf=NULL;
+ }
+ if (!this->compr_buf) {
+ spin_unlock(&jffs2_compressor_list_lock);
+ tmp_buf = kmalloc(orig_dlen,GFP_KERNEL);
+ spin_lock(&jffs2_compressor_list_lock);
+ if (!tmp_buf) {
+ printk(KERN_WARNING "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++;
+ spin_unlock(&jffs2_compressor_list_lock);
+ *datalen = orig_slen;
+ *cdatalen = orig_dlen;
+ compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL);
+ spin_lock(&jffs2_compressor_list_lock);
+ this->usecount--;
+ if (!compr_ret) {
+ 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;
+ }
+ spin_unlock(&jffs2_compressor_list_lock);
+ break;
+ default:
+ printk(KERN_ERR "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_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+ uint16_t comprtype, unsigned char *cdata_in,
+ unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
+{
+ struct jffs2_compressor *this;
+ int ret;
+
+ /* Older code had a bug where it would write non-zero 'usercompr'
+ fields. Deal with it. */
+ if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
+ comprtype &= 0xff;
+
+ switch (comprtype & 0xff) {
+ case JFFS2_COMPR_NONE:
+ /* This should be special-cased elsewhere, but we might as well deal with it */
+ memcpy(data_out, cdata_in, datalen);
+ none_stat_decompr_blocks++;
+ break;
+ case JFFS2_COMPR_ZERO:
+ memset(data_out, 0, datalen);
+ break;
+ default:
+ spin_lock(&jffs2_compressor_list_lock);
+ list_for_each_entry(this, &jffs2_compressor_list, list) {
+ if (comprtype == this->compr) {
+ this->usecount++;
+ spin_unlock(&jffs2_compressor_list_lock);
+ ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL);
+ spin_lock(&jffs2_compressor_list_lock);
+ if (ret) {
+ printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
+ }
+ else {
+ this->stat_decompr_blocks++;
+ }
+ this->usecount--;
+ spin_unlock(&jffs2_compressor_list_lock);
+ return ret;
+ }
+ }
+ printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype);
+ spin_unlock(&jffs2_compressor_list_lock);
+ return -EIO;
+ }
+ return 0;
+}
+
+int jffs2_register_compressor(struct jffs2_compressor *comp)
+{
+ struct jffs2_compressor *this;
+
+ if (!comp->name) {
+ printk(KERN_WARNING "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;
+ D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));
+
+ spin_lock(&jffs2_compressor_list_lock);
+
+ 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;
+}