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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 21b4103..fc81022 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -417,6 +417,11 @@
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 @@
* 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 @@
Opt_no_bulk_read,
Opt_chk_data_crc,
Opt_no_chk_data_crc,
+ Opt_override_compr,
Opt_err,
};
@@ -897,6 +904,7 @@
{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 @@
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 @@
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 @@
/*
* 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);