forked from Minki/linux
jffs2: add compr=lzo and compr=zlib options
..to allow forcing of either compression scheme. This will override compiled-in defaults. jffs2_compress is reworked a bit, as the lzo/zlib override shares lots of code w/ the PRIORITY mode. v2: update show_options accordingly. Signed-off-by: Andres Salomon <dilinger@queued.net> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This commit is contained in:
Andres Salomon
Artem Bityutskiy
parent
92abc475d8
commit
123005f3cc
119
fs/jffs2/compr.c
119
fs/jffs2/compr.c
@ -53,6 +53,78 @@ static int jffs2_is_best_compression(struct jffs2_compressor *this,
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return 0;
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}
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/*
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* jffs2_selected_compress:
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* @compr: Explicit compression type to use (ie, JFFS2_COMPR_ZLIB).
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* If 0, just take the first available compression mode.
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* @data_in: Pointer to uncompressed data
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* @cpage_out: Pointer to returned pointer to buffer for compressed data
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* @datalen: On entry, holds the amount of data available for compression.
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* On exit, expected to hold the amount of data actually compressed.
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* @cdatalen: On entry, holds the amount of space available for compressed
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* data. On exit, expected to hold the actual size of the compressed
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* data.
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*
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* Returns: the compression type used. Zero is used to show that the data
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* could not be compressed; probably because we couldn't find the requested
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* compression mode.
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*/
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static int jffs2_selected_compress(u8 compr, unsigned char *data_in,
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unsigned char **cpage_out, u32 *datalen, u32 *cdatalen)
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{
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struct jffs2_compressor *this;
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int err, ret = JFFS2_COMPR_NONE;
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uint32_t orig_slen, orig_dlen;
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char *output_buf;
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output_buf = kmalloc(*cdatalen, GFP_KERNEL);
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if (!output_buf) {
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printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
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return ret;
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}
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orig_slen = *datalen;
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orig_dlen = *cdatalen;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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/* Skip decompress-only and disabled modules */
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if (!this->compress || this->disabled)
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continue;
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/* Skip if not the desired compression type */
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if (compr && (compr != this->compr))
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continue;
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/*
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* Either compression type was unspecified, or we found our
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* compressor; either way, we're good to go.
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*/
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this->usecount++;
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spin_unlock(&jffs2_compressor_list_lock);
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*datalen = orig_slen;
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*cdatalen = orig_dlen;
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err = this->compress(data_in, output_buf, datalen, cdatalen);
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spin_lock(&jffs2_compressor_list_lock);
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this->usecount--;
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if (!err) {
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/* Success */
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ret = this->compr;
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this->stat_compr_blocks++;
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this->stat_compr_orig_size += *datalen;
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this->stat_compr_new_size += *cdatalen;
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break;
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}
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}
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spin_unlock(&jffs2_compressor_list_lock);
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if (ret == JFFS2_COMPR_NONE)
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kfree(output_buf);
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else
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*cpage_out = output_buf;
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return ret;
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}
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/* jffs2_compress:
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* @data_in: Pointer to uncompressed data
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* @cpage_out: Pointer to returned pointer to buffer for compressed data
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@ -91,37 +163,8 @@ uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
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case JFFS2_COMPR_MODE_NONE:
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break;
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case JFFS2_COMPR_MODE_PRIORITY:
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output_buf = kmalloc(*cdatalen,GFP_KERNEL);
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if (!output_buf) {
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printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
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goto out;
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}
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orig_slen = *datalen;
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orig_dlen = *cdatalen;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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/* Skip decompress-only backwards-compatibility and disabled modules */
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if ((!this->compress)||(this->disabled))
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continue;
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this->usecount++;
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spin_unlock(&jffs2_compressor_list_lock);
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*datalen = orig_slen;
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*cdatalen = orig_dlen;
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compr_ret = this->compress(data_in, output_buf, datalen, cdatalen);
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spin_lock(&jffs2_compressor_list_lock);
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this->usecount--;
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if (!compr_ret) {
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ret = this->compr;
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this->stat_compr_blocks++;
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this->stat_compr_orig_size += *datalen;
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this->stat_compr_new_size += *cdatalen;
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break;
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}
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}
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spin_unlock(&jffs2_compressor_list_lock);
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if (ret == JFFS2_COMPR_NONE)
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kfree(output_buf);
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ret = jffs2_selected_compress(0, data_in, cpage_out, datalen,
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cdatalen);
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break;
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case JFFS2_COMPR_MODE_SIZE:
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case JFFS2_COMPR_MODE_FAVOURLZO:
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@ -179,22 +222,28 @@ uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
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best->stat_compr_orig_size += best_slen;
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best->stat_compr_new_size += best_dlen;
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ret = best->compr;
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*cpage_out = output_buf;
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}
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spin_unlock(&jffs2_compressor_list_lock);
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break;
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case JFFS2_COMPR_MODE_FORCELZO:
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ret = jffs2_selected_compress(JFFS2_COMPR_LZO, data_in,
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cpage_out, datalen, cdatalen);
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break;
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case JFFS2_COMPR_MODE_FORCEZLIB:
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ret = jffs2_selected_compress(JFFS2_COMPR_ZLIB, data_in,
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cpage_out, datalen, cdatalen);
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break;
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default:
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printk(KERN_ERR "JFFS2: unknown compression mode.\n");
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}
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out:
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if (ret == JFFS2_COMPR_NONE) {
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*cpage_out = data_in;
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*datalen = *cdatalen;
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none_stat_compr_blocks++;
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none_stat_compr_size += *datalen;
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}
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else {
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*cpage_out = output_buf;
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}
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return ret;
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}
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@ -40,6 +40,8 @@
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#define JFFS2_COMPR_MODE_PRIORITY 1
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#define JFFS2_COMPR_MODE_SIZE 2
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#define JFFS2_COMPR_MODE_FAVOURLZO 3
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#define JFFS2_COMPR_MODE_FORCELZO 4
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#define JFFS2_COMPR_MODE_FORCEZLIB 5
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#define FAVOUR_LZO_PERCENT 80
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@ -82,6 +82,14 @@ static const char *jffs2_compr_name(unsigned int compr)
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switch (compr) {
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case JFFS2_COMPR_MODE_NONE:
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return "none";
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#ifdef CONFIG_JFFS2_LZO
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case JFFS2_COMPR_MODE_FORCELZO:
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return "lzo";
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#endif
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#ifdef CONFIG_JFFS2_ZLIB
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case JFFS2_COMPR_MODE_FORCEZLIB:
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return "zlib";
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#endif
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default:
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/* should never happen; programmer error */
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WARN_ON(1);
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@ -195,11 +203,25 @@ static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
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if (!name)
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return -ENOMEM;
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if (!strcmp(name, "none")) {
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if (!strcmp(name, "none"))
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c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
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c->mount_opts.override_compr = true;
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#ifdef CONFIG_JFFS2_LZO
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else if (!strcmp(name, "lzo"))
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c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
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#endif
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#ifdef CONFIG_JFFS2_ZLIB
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else if (!strcmp(name, "zlib"))
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c->mount_opts.compr =
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JFFS2_COMPR_MODE_FORCEZLIB;
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#endif
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else {
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printk(KERN_ERR "JFFS2 Error: unknown compressor \"%s\"",
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name);
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kfree(name);
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return -EINVAL;
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}
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kfree(name);
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c->mount_opts.override_compr = true;
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break;
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default:
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printk(KERN_ERR "JFFS2 Error: unrecognized mount option '%s' or missing value\n",
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