Commit 553dea4d authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBIFS: introduce compression mount options 



It is very handy to be able to change default UBIFS compressor
via mount options. Introduce -o compr=<name> mount option support.
Currently only "none", "lzo" and "zlib" compressors are supported.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent a1dc080c

Documentation/filesystems/ubifs.txt

+3 −0
Original line number Diff line number Diff line
@@ -95,6 +95,9 @@ no_chk_data_crc skip checking of CRCs on data nodes in order to 
			of this option is that corruption of the contents

			of a file can go unnoticed.

chk_data_crc (*)	do not skip checking CRCs on data nodes

compr=none              override defoult comressor and set it to "none"

compr=lzo               override defoult comressor and set it to "lzo"

compr=zlib              override defoult comressor and set it to "zlib"





Quick usage instructions

fs/ubifs/compress.c

+3 −3
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ 
/* Fake description object for the "none" compressor */

static struct ubifs_compressor none_compr = {

	.compr_type = UBIFS_COMPR_NONE,

	.name = "no compression",

	.name = "none",

	.capi_name = "",

};
@@ -43,13 +43,13 @@ static DEFINE_MUTEX(lzo_mutex); 
static struct ubifs_compressor lzo_compr = {

	.compr_type = UBIFS_COMPR_LZO,

	.comp_mutex = &lzo_mutex,

	.name = "LZO",

	.name = "lzo",

	.capi_name = "lzo",

};

#else

static struct ubifs_compressor lzo_compr = {

	.compr_type = UBIFS_COMPR_LZO,

	.name = "LZO",

	.name = "lzo",

};

#endif

fs/ubifs/sb.c

+6 −4
Original line number Diff line number Diff line
@@ -179,8 +179,11 @@ static int create_default_filesystem(struct ubifs_info *c) 
	sup->fanout        = cpu_to_le32(DEFAULT_FANOUT);

	sup->lsave_cnt     = cpu_to_le32(c->lsave_cnt);

	sup->fmt_version   = cpu_to_le32(UBIFS_FORMAT_VERSION);

	sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);

	sup->time_gran     = cpu_to_le32(DEFAULT_TIME_GRAN);

	if (c->mount_opts.override_compr)

		sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);

	else

		sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);



	generate_random_uuid(sup->uuid);
@@ -582,16 +585,15 @@ int ubifs_read_superblock(struct ubifs_info *c) 
	c->jhead_cnt     = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;

	c->fanout        = le32_to_cpu(sup->fanout);

	c->lsave_cnt     = le32_to_cpu(sup->lsave_cnt);

	c->default_compr = le16_to_cpu(sup->default_compr);

	c->rp_size       = le64_to_cpu(sup->rp_size);

	c->rp_uid        = le32_to_cpu(sup->rp_uid);

	c->rp_gid        = le32_to_cpu(sup->rp_gid);

	sup_flags        = le32_to_cpu(sup->flags);

	if (!c->mount_opts.override_compr)

		c->default_compr = le16_to_cpu(sup->default_compr);



	c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);



	memcpy(&c->uuid, &sup->uuid, 16);



	c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);



	/* Automatically increase file system size to the maximum size */

fs/ubifs/super.c

+37 −7
Original line number Diff line number Diff line
@@ -417,6 +417,11 @@ static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt) 
	else if (c->mount_opts.chk_data_crc == 1)

		seq_printf(s, ",no_chk_data_crc");



	if (c->mount_opts.override_compr) {

		seq_printf(s, ",compr=");

		seq_printf(s, ubifs_compr_name(c->mount_opts.compr_type));

	}



	return 0;

}
@@ -878,6 +883,7 @@ static int check_volume_empty(struct ubifs_info *c) 
 * Opt_no_bulk_read: disable bulk-reads

 * Opt_chk_data_crc: check CRCs when reading data nodes

 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes

 * Opt_override_compr: override default compressor

 * Opt_err: just end of array marker

 */

enum {
@@ -887,6 +893,7 @@ enum { 
	Opt_no_bulk_read,

	Opt_chk_data_crc,

	Opt_no_chk_data_crc,

	Opt_override_compr,

	Opt_err,

};
@@ -897,6 +904,7 @@ static const match_table_t tokens = { 
	{Opt_no_bulk_read, "no_bulk_read"},

	{Opt_chk_data_crc, "chk_data_crc"},

	{Opt_no_chk_data_crc, "no_chk_data_crc"},

	{Opt_override_compr, "compr=%s"},

	{Opt_err, NULL},

};
@@ -950,6 +958,28 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options, 
			c->mount_opts.chk_data_crc = 1;

			c->no_chk_data_crc = 1;

			break;

		case Opt_override_compr:

		{

			char *name = match_strdup(&args[0]);



			if (!name)

				return -ENOMEM;

			if (!strcmp(name, "none"))

				c->mount_opts.compr_type = UBIFS_COMPR_NONE;

			else if (!strcmp(name, "lzo"))

				c->mount_opts.compr_type = UBIFS_COMPR_LZO;

			else if (!strcmp(name, "zlib"))

				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;

			else {

				ubifs_err("unknown compressor \"%s\"", name);

				kfree(name);

				return -EINVAL;

			}

			kfree(name);

			c->mount_opts.override_compr = 1;

			c->default_compr = c->mount_opts.compr_type;

			break;

		}

		default:

			ubifs_err("unrecognized mount option \"%s\" "

				  "or missing value", p);
@@ -1100,13 +1130,13 @@ static int mount_ubifs(struct ubifs_info *c) 
		goto out_free;



	/*

	 * Make sure the compressor which is set as the default on in the

	 * superblock was actually compiled in.

	 * Make sure the compressor which is set as default in the superblock

	 * or overriden by mount options is actually compiled in.

	 */

	if (!ubifs_compr_present(c->default_compr)) {

		ubifs_warn("'%s' compressor is set by superblock, but not "

			   "compiled in", ubifs_compr_name(c->default_compr));

		c->default_compr = UBIFS_COMPR_NONE;

		ubifs_err("'compressor \"%s\" is not compiled in",

			  ubifs_compr_name(c->default_compr));

		goto out_free;

	}



	dbg_failure_mode_registration(c);
@@ -2023,8 +2053,8 @@ static int __init ubifs_init(void) 
	/*

	 * We use 2 bit wide bit-fields to store compression type, which should

	 * be amended if more compressors are added. The bit-fields are:

	 * @compr_type in 'struct ubifs_inode' and @default_compr in

	 * 'struct ubifs_info'.

	 * @compr_type in 'struct ubifs_inode', @default_compr in

	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.

	 */

	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);

fs/ubifs/ubifs.h

+10 −2
Original line number Diff line number Diff line
@@ -893,13 +893,21 @@ struct ubifs_orphan { 
/**

 * struct ubifs_mount_opts - UBIFS-specific mount options information.

 * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)

 * @bulk_read: enable bulk-reads

 * @chk_data_crc: check CRCs when reading data nodes

 * @bulk_read: enable/disable bulk-reads (%0 default, %1 disabe, %2 enable)

 * @chk_data_crc: enable/disable CRC data checking when reading data nodes

 *                (%0 default, %1 disabe, %2 enable)

 * @override_compr: override default compressor (%0 - do not override and use

 *                  superblock compressor, %1 - override and use compressor

 *                  specified in @compr_type)

 * @compr_type: compressor type to override the superblock compressor with

 *              (%UBIFS_COMPR_NONE, etc)

 */

struct ubifs_mount_opts {

	unsigned int unmount_mode:2;

	unsigned int bulk_read:2;

	unsigned int chk_data_crc:2;

	unsigned int override_compr:1;

	unsigned int compr_type:2;

};



/**