On 12/7/21 5:35 PM, Eric Biggers wrote:
+What: /sys/block/<disk>/queue/crypto/modes/<mode>
+Date: December 2021
+Contact: linux-block@xxxxxxxxxxxxxxx
+Description:
+ [RO] For each crypto mode (i.e., encryption/decryption
+ algorithm) the device supports with inline encryption, a file
+ will exist at this location. It will contain a hexadecimal
+ number that is a bitmask of the supported data unit sizes, in
+ bytes, for that crypto mode.
+
+ Currently, the crypto modes that may be supported are:
+
+ * AES-256-XTS
+ * AES-128-CBC-ESSIV
+ * Adiantum
+
+ For example, if a device supports AES-256-XTS inline encryption
+ with data unit sizes of 512 and 4096 bytes, the file
+ /sys/block/<disk>/queue/crypto/modes/AES-256-XTS will exist and
+ will contain "0x1200".
So a bitmask is used to combine multiple values into a single number? Has it been
considered to report each value separately, e.g. 512\n4096\n instead of 0x1200\n?
I think the former approach is more friendly for shell scripts.
+struct blk_crypto_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct blk_crypto_profile *profile,
+ struct blk_crypto_attr *attr, char *page);
+};
It is not clear to me why this structure has been introduced instead of using the
existing kobj_attribute structure?
+static int __init blk_crypto_sysfs_init(void)
+{
+ int i;
+
+ BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+ for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+ struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
+
+ attr->attr.name = blk_crypto_modes[i].name;
+ attr->attr.mode = 0444;
+ attr->show = blk_crypto_mode_show;
+ blk_crypto_mode_attrs[i - 1] = &attr->attr;
+ }
+ return 0;
+}
+subsys_initcall(blk_crypto_sysfs_init);
Would it be possible to remove the use of subsys_initcall() if the crypto attributes and
blk_crypto_modes[] would be defined in the same file?
Thanks,
Bart.
