diff options
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 75 | ||||
| -rw-r--r-- | init/do_mounts.c | 70 | ||||
| -rw-r--r-- | init/main.c | 2 |
3 files changed, 110 insertions, 37 deletions
diff --git a/init/Kconfig b/init/Kconfig index 36890f0..fdfd97e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -71,7 +71,7 @@ config BROKEN_ON_SMP config LOCK_KERNEL bool - depends on SMP || PREEMPT + depends on (SMP || PREEMPT) && BKL default y config INIT_ENV_ARG_LIMIT @@ -661,11 +661,14 @@ config BLK_CGROUP Currently, CFQ IO scheduler uses it to recognize task groups and control disk bandwidth allocation (proportional time slice allocation) - to such task groups. + to such task groups. It is also used by bio throttling logic in + block layer to implement upper limit in IO rates on a device. This option only enables generic Block IO controller infrastructure. - One needs to also enable actual IO controlling logic in CFQ for it - to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y). + One needs to also enable actual IO controlling logic/policy. For + enabling proportional weight division of disk bandwidth in CFQ seti + CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set + CONFIG_BLK_THROTTLE=y. See Documentation/cgroups/blkio-controller.txt for more information. @@ -683,40 +686,42 @@ config MM_OWNER bool config SYSFS_DEPRECATED - bool - -config SYSFS_DEPRECATED_V2 bool "enable deprecated sysfs features to support old userspace tools" depends on SYSFS default n - select SYSFS_DEPRECATED - help - This option switches the layout of sysfs to the deprecated - version. Do not use it on recent distributions. - - The current sysfs layout features a unified device tree at - /sys/devices/, which is able to express a hierarchy between - class devices. If the deprecated option is set to Y, the - unified device tree is split into a bus device tree at - /sys/devices/ and several individual class device trees at - /sys/class/. The class and bus devices will be connected by - "<subsystem>:<name>" and the "device" links. The "block" - class devices, will not show up in /sys/class/block/. Some - subsystems will suppress the creation of some devices which - depend on the unified device tree. - - This option is not a pure compatibility option that can - be safely enabled on newer distributions. It will change the - layout of sysfs to the non-extensible deprecated version, - and disable some features, which can not be exported without - confusing older userspace tools. Since 2007/2008 all major - distributions do not enable this option, and ship no tools which - depend on the deprecated layout or this option. - - If you are using a new kernel on an older distribution, or use - older userspace tools, you might need to say Y here. Do not say Y, - if the original kernel, that came with your distribution, has - this option set to N. + help + This option adds code that switches the layout of the "block" class + devices, to not show up in /sys/class/block/, but only in + /sys/block/. + + This switch is only active when the sysfs.deprecated=1 boot option is + passed or the SYSFS_DEPRECATED_V2 option is set. + + This option allows new kernels to run on old distributions and tools, + which might get confused by /sys/class/block/. Since 2007/2008 all + major distributions and tools handle this just fine. + + Recent distributions and userspace tools after 2009/2010 depend on + the existence of /sys/class/block/, and will not work with this + option enabled. + + Only if you are using a new kernel on an old distribution, you might + need to say Y here. + +config SYSFS_DEPRECATED_V2 + bool "enabled deprecated sysfs features by default" + default n + depends on SYSFS + depends on SYSFS_DEPRECATED + help + Enable deprecated sysfs by default. + + See the CONFIG_SYSFS_DEPRECATED option for more details about this + option. + + Only if you are using a new kernel on an old distribution, you might + need to say Y here. Even then, odds are you would not need it + enabled, you can always pass the boot option if absolutely necessary. config RELAY bool "Kernel->user space relay support (formerly relayfs)" diff --git a/init/do_mounts.c b/init/do_mounts.c index 02e3ca4..42db055 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -58,6 +58,62 @@ static int __init readwrite(char *str) __setup("ro", readonly); __setup("rw", readwrite); +#ifdef CONFIG_BLOCK +/** + * match_dev_by_uuid - callback for finding a partition using its uuid + * @dev: device passed in by the caller + * @data: opaque pointer to a 36 byte char array with a UUID + * + * Returns 1 if the device matches, and 0 otherwise. + */ +static int match_dev_by_uuid(struct device *dev, void *data) +{ + u8 *uuid = data; + struct hd_struct *part = dev_to_part(dev); + + if (!part->info) + goto no_match; + + if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid))) + goto no_match; + + return 1; +no_match: + return 0; +} + + +/** + * devt_from_partuuid - looks up the dev_t of a partition by its UUID + * @uuid: 36 byte char array containing a hex ascii UUID + * + * The function will return the first partition which contains a matching + * UUID value in its partition_meta_info struct. This does not search + * by filesystem UUIDs. + * + * Returns the matching dev_t on success or 0 on failure. + */ +static dev_t __init devt_from_partuuid(char *uuid_str) +{ + dev_t res = 0; + struct device *dev = NULL; + u8 uuid[16]; + + /* Pack the requested UUID in the expected format. */ + part_pack_uuid(uuid_str, uuid); + + dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid); + if (!dev) + goto done; + + res = dev->devt; + put_device(dev); + +done: + return res; +} +#endif + /* * Convert a name into device number. We accept the following variants: * @@ -68,6 +124,8 @@ __setup("rw", readwrite); * of partition - device number of disk plus the partition number * 5) /dev/<disk_name>p<decimal> - same as the above, that form is * used when disk name of partitioned disk ends on a digit. + * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the + * unique id of a partition if the partition table provides it. * * If name doesn't have fall into the categories above, we return (0,0). * block_class is used to check if something is a disk name. If the disk @@ -82,6 +140,18 @@ dev_t name_to_dev_t(char *name) dev_t res = 0; int part; +#ifdef CONFIG_BLOCK + if (strncmp(name, "PARTUUID=", 9) == 0) { + name += 9; + if (strlen(name) != 36) + goto fail; + res = devt_from_partuuid(name); + if (!res) + goto fail; + goto done; + } +#endif + if (strncmp(name, "/dev/", 5) != 0) { unsigned maj, min; diff --git a/init/main.c b/init/main.c index 9684c96..e59af24 100644 --- a/init/main.c +++ b/init/main.c @@ -424,7 +424,6 @@ static void __init setup_command_line(char *command_line) static __initdata DECLARE_COMPLETION(kthreadd_done); static noinline void __init_refok rest_init(void) - __releases(kernel_lock) { int pid; @@ -818,7 +817,6 @@ static void run_init_process(const char *init_filename) * makes it inline to init() and it becomes part of init.text section */ static noinline int init_post(void) - __releases(kernel_lock) { /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); |