3 files changed, 109 insertions, 11 deletions

diff --git a/init/Kconfig b/init/Kconfig
index d742b6fca8d2..fdfd97efe0e0 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -21,6 +21,13 @@ config CONSTRUCTORS
         depends on !UML
         default y
 
+config HAVE_IRQ_WORK
+        bool
+
+config IRQ_WORK
+        bool
+        depends on HAVE_IRQ_WORK
+
 menu "General setup"
 
 config EXPERIMENTAL
@@ -64,7 +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
@@ -332,6 +339,8 @@ config AUDIT_TREE
         depends on AUDITSYSCALL
         select FSNOTIFY
 
+source "kernel/irq/Kconfig"
+
 menu "RCU Subsystem"
 
 choice
@@ -340,6 +349,7 @@ choice
 
 config TREE_RCU
         bool "Tree-based hierarchical RCU"
+        depends on !PREEMPT && SMP
         help
           This option selects the RCU implementation that is
           designed for very large SMP system with hundreds or
@@ -347,7 +357,7 @@ config TREE_RCU
           smaller systems.
 
 config TREE_PREEMPT_RCU
-        bool "Preemptable tree-based hierarchical RCU"
+        bool "Preemptible tree-based hierarchical RCU"
         depends on PREEMPT
         help
           This option selects the RCU implementation that is
@@ -365,8 +375,22 @@ config TINY_RCU
           is not required.  This option greatly reduces the
           memory footprint of RCU.
 
+config TINY_PREEMPT_RCU
+        bool "Preemptible UP-only small-memory-footprint RCU"
+        depends on !SMP && PREEMPT
+        help
+          This option selects the RCU implementation that is designed
+          for real-time UP systems.  This option greatly reduces the
+          memory footprint of RCU.
+
 endchoice
 
+config PREEMPT_RCU
+        def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
+        help
+          This option enables preemptible-RCU code that is common between
+          the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+
 config RCU_TRACE
         bool "Enable tracing for RCU"
         depends on TREE_RCU || TREE_PREEMPT_RCU
@@ -387,9 +411,12 @@ config RCU_FANOUT
         help
           This option controls the fanout of hierarchical implementations
           of RCU, allowing RCU to work efficiently on machines with
-          large numbers of CPUs.  This value must be at least the cube
-          root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
-          systems and up to 262,144 for 64-bit systems.
+          large numbers of CPUs.  This value must be at least the fourth
+          root of NR_CPUS, which allows NR_CPUS to be insanely large.
+          The default value of RCU_FANOUT should be used for production
+          systems, but if you are stress-testing the RCU implementation
+          itself, small RCU_FANOUT values allow you to test large-system
+          code paths on small(er) systems.
 
           Select a specific number if testing RCU itself.
           Take the default if unsure.
@@ -634,11 +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.
 
@@ -989,6 +1019,7 @@ config PERF_EVENTS
         default y if (PROFILING || PERF_COUNTERS)
         depends on HAVE_PERF_EVENTS
         select ANON_INODES
+        select IRQ_WORK
         help
           Enable kernel support for various performance events provided
           by software and hardware.
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 02e3ca4fc527..42db0551c3aa 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 94ab488039aa..e59af24a0b7c 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;
 
@@ -556,7 +555,6 @@ asmlinkage void __init start_kernel(void)
 
         local_irq_disable();
         early_boot_irqs_off();
-        early_init_irq_lock_class();
 
 /*
  * Interrupts are still disabled. Do necessary setups, then
@@ -819,7 +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();