Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits)
  cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
  loop: Update mtime when writing using aops
  block: expose the statistics in blkio.time and blkio.sectors for the root cgroup
  backing-dev: Handle class_create() failure
  Block: Fix block/elevator.c elevator_get() off-by-one error
  drbd: lc_element_by_index() never returns NULL
  cciss: unlock on error path
  cfq-iosched: Do not merge queues of BE and IDLE classes
  cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging
  i2o: Remove the dangerous kobj_to_i2o_device macro
  block: remove 16 bytes of padding from struct request on 64bits
  cfq-iosched: fix a kbuild regression
  block: make CONFIG_BLK_CGROUP visible
  Remove GENHD_FL_DRIVERFS
  block: Export max number of segments and max segment size in sysfs
  block: Finalize conversion of block limits functions
  block: Fix overrun in lcm() and move it to lib
  vfs: improve writeback_inodes_wb()
  paride: fix off-by-one test
  drbd: fix al-to-on-disk-bitmap for 4k logical_block_size
  ...

8 files changed, 185 insertions, 33 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ebd22dbed861..6690e8bae7bb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -158,7 +158,6 @@ enum rq_flag_bits {
 struct request {
         struct list_head queuelist;
         struct call_single_data csd;
-        int cpu;
 
         struct request_queue *q;
 
@@ -166,9 +165,11 @@ struct request {
         enum rq_cmd_type_bits cmd_type;
         unsigned long atomic_flags;
 
+        int cpu;
+
         /* the following two fields are internal, NEVER access directly */
-        sector_t __sector;              /* sector cursor */
         unsigned int __data_len;        /* total data len */
+        sector_t __sector;              /* sector cursor */
 
         struct bio *bio;
         struct bio *biotail;
@@ -201,20 +202,20 @@ struct request {
 
         unsigned short ioprio;
 
+        int ref_count;
+
         void *special;          /* opaque pointer available for LLD use */
         char *buffer;           /* kaddr of the current segment if available */
 
         int tag;
         int errors;
 
-        int ref_count;
-
         /*
          * when request is used as a packet command carrier
          */
-        unsigned short cmd_len;
         unsigned char __cmd[BLK_MAX_CDB];
         unsigned char *cmd;
+        unsigned short cmd_len;
 
         unsigned int extra_len; /* length of alignment and padding */
         unsigned int sense_len;
@@ -921,26 +922,7 @@ extern void blk_cleanup_queue(struct request_queue *);
 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 extern void blk_queue_bounce_limit(struct request_queue *, u64);
 extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
-
-/* Temporary compatibility wrapper */
-static inline void blk_queue_max_sectors(struct request_queue *q, unsigned int max)
-{
-        blk_queue_max_hw_sectors(q, max);
-}
-
 extern void blk_queue_max_segments(struct request_queue *, unsigned short);
-
-static inline void blk_queue_max_phys_segments(struct request_queue *q, unsigned short max)
-{
-        blk_queue_max_segments(q, max);
-}
-
-static inline void blk_queue_max_hw_segments(struct request_queue *q, unsigned short max)
-{
-        blk_queue_max_segments(q, max);
-}
-
-
 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 extern void blk_queue_max_discard_sectors(struct request_queue *q,
                 unsigned int max_discard_sectors);
@@ -1030,11 +1012,6 @@ static inline int sb_issue_discard(struct super_block *sb,
 
 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
 
-#define MAX_PHYS_SEGMENTS 128
-#define MAX_HW_SEGMENTS 128
-#define SAFE_MAX_SECTORS 255
-#define MAX_SEGMENT_SIZE        65536
-
 enum blk_default_limits {
         BLK_MAX_SEGMENTS        = 128,
         BLK_SAFE_MAX_SECTORS    = 255,
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 78962272338a..4341b1a97a34 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -56,7 +56,7 @@ extern const char *drbd_buildtag(void);
 #define REL_VERSION "8.3.7"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
-#define PRO_VERSION_MAX 91
+#define PRO_VERSION_MAX 92
 
 
 enum drbd_io_error_p {
diff --git a/include/linux/drbd_nl.h b/include/linux/drbd_nl.h
index a4d82f895994..f7431a4ca608 100644
--- a/include/linux/drbd_nl.h
+++ b/include/linux/drbd_nl.h
@@ -12,7 +12,7 @@
 #endif
 
 NL_PACKET(primary, 1,
-       NL_BIT(          1,      T_MAY_IGNORE,   overwrite_peer)
+       NL_BIT(          1,      T_MAY_IGNORE,   primary_force)
 )
 
 NL_PACKET(secondary, 2, )
@@ -63,6 +63,7 @@ NL_PACKET(net_conf, 5,
         NL_BIT(         41,     T_MAY_IGNORE,   always_asbp)
         NL_BIT(         61,     T_MAY_IGNORE,   no_cork)
         NL_BIT(         62,     T_MANDATORY,    auto_sndbuf_size)
+        NL_BIT(         70,     T_MANDATORY,    dry_run)
 )
 
 NL_PACKET(disconnect, 6, )
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 56b50514ab25..5f2f4c4d8fb0 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -109,7 +109,7 @@ struct hd_struct {
 };
 
 #define GENHD_FL_REMOVABLE                      1
-#define GENHD_FL_DRIVERFS                       2
+/* 2 is unused */
 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 #define GENHD_FL_CD                             8
 #define GENHD_FL_UP                             16
diff --git a/include/linux/i2o.h b/include/linux/i2o.h
index 87018dc5527d..9e7a12d6385d 100644
--- a/include/linux/i2o.h
+++ b/include/linux/i2o.h
@@ -782,7 +782,6 @@ extern int i2o_exec_lct_get(struct i2o_controller *);
 #define to_i2o_driver(drv) container_of(drv,struct i2o_driver, driver)
 #define to_i2o_device(dev) container_of(dev, struct i2o_device, device)
 #define to_i2o_controller(dev) container_of(dev, struct i2o_controller, device)
-#define kobj_to_i2o_device(kobj) to_i2o_device(container_of(kobj, struct device, kobj))
 
 /**
  *      i2o_out_to_virt - Turn an I2O message to a virtual address
diff --git a/include/linux/lcm.h b/include/linux/lcm.h
new file mode 100644
index 000000000000..7bf01d779b45
--- /dev/null
+++ b/include/linux/lcm.h
@@ -0,0 +1,8 @@
+#ifndef _LCM_H
+#define _LCM_H
+
+#include <linux/compiler.h>
+
+unsigned long lcm(unsigned long a, unsigned long b) __attribute_const__;
+
+#endif /* _LCM_H */
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 76e8903cd204..36520ded3e06 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -34,6 +34,9 @@ struct writeback_control {
         enum writeback_sync_modes sync_mode;
         unsigned long *older_than_this; /* If !NULL, only write back inodes
                                            older than this */
+        unsigned long wb_start;         /* Time writeback_inodes_wb was
+                                           called. This is needed to avoid
+                                           extra jobs and livelock */
         long nr_to_write;               /* Write this many pages, and decrement
                                            this for each page written */
         long pages_skipped;             /* Pages which were not written */
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 5fb72733331e..d870a918559c 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -40,6 +40,16 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
                   __entry->nr_sector, __entry->errors)
 );
 
+/**
+ * block_rq_abort - abort block operation request
+ * @q: queue containing the block operation request
+ * @rq: block IO operation request
+ *
+ * Called immediately after pending block IO operation request @rq in
+ * queue @q is aborted. The fields in the operation request @rq
+ * can be examined to determine which device and sectors the pending
+ * operation would access.
+ */
 DEFINE_EVENT(block_rq_with_error, block_rq_abort,
 
         TP_PROTO(struct request_queue *q, struct request *rq),
@@ -47,6 +57,15 @@ DEFINE_EVENT(block_rq_with_error, block_rq_abort,
         TP_ARGS(q, rq)
 );
 
+/**
+ * block_rq_requeue - place block IO request back on a queue
+ * @q: queue holding operation
+ * @rq: block IO operation request
+ *
+ * The block operation request @rq is being placed back into queue
+ * @q.  For some reason the request was not completed and needs to be
+ * put back in the queue.
+ */
 DEFINE_EVENT(block_rq_with_error, block_rq_requeue,
 
         TP_PROTO(struct request_queue *q, struct request *rq),
@@ -54,6 +73,17 @@ DEFINE_EVENT(block_rq_with_error, block_rq_requeue,
         TP_ARGS(q, rq)
 );
 
+/**
+ * block_rq_complete - block IO operation completed by device driver
+ * @q: queue containing the block operation request
+ * @rq: block operations request
+ *
+ * The block_rq_complete tracepoint event indicates that some portion
+ * of operation request has been completed by the device driver.  If
+ * the @rq->bio is %NULL, then there is absolutely no additional work to
+ * do for the request. If @rq->bio is non-NULL then there is
+ * additional work required to complete the request.
+ */
 DEFINE_EVENT(block_rq_with_error, block_rq_complete,
 
         TP_PROTO(struct request_queue *q, struct request *rq),
@@ -95,6 +125,16 @@ DECLARE_EVENT_CLASS(block_rq,
                   __entry->nr_sector, __entry->comm)
 );
 
+/**
+ * block_rq_insert - insert block operation request into queue
+ * @q: target queue
+ * @rq: block IO operation request
+ *
+ * Called immediately before block operation request @rq is inserted
+ * into queue @q.  The fields in the operation request @rq struct can
+ * be examined to determine which device and sectors the pending
+ * operation would access.
+ */
 DEFINE_EVENT(block_rq, block_rq_insert,
 
         TP_PROTO(struct request_queue *q, struct request *rq),
@@ -102,6 +142,14 @@ DEFINE_EVENT(block_rq, block_rq_insert,
         TP_ARGS(q, rq)
 );
 
+/**
+ * block_rq_issue - issue pending block IO request operation to device driver
+ * @q: queue holding operation
+ * @rq: block IO operation operation request
+ *
+ * Called when block operation request @rq from queue @q is sent to a
+ * device driver for processing.
+ */
 DEFINE_EVENT(block_rq, block_rq_issue,
 
         TP_PROTO(struct request_queue *q, struct request *rq),
@@ -109,6 +157,17 @@ DEFINE_EVENT(block_rq, block_rq_issue,
         TP_ARGS(q, rq)
 );
 
+/**
+ * block_bio_bounce - used bounce buffer when processing block operation
+ * @q: queue holding the block operation
+ * @bio: block operation
+ *
+ * A bounce buffer was used to handle the block operation @bio in @q.
+ * This occurs when hardware limitations prevent a direct transfer of
+ * data between the @bio data memory area and the IO device.  Use of a
+ * bounce buffer requires extra copying of data and decreases
+ * performance.
+ */
 TRACE_EVENT(block_bio_bounce,
 
         TP_PROTO(struct request_queue *q, struct bio *bio),
@@ -138,6 +197,14 @@ TRACE_EVENT(block_bio_bounce,
                   __entry->nr_sector, __entry->comm)
 );
 
+/**
+ * block_bio_complete - completed all work on the block operation
+ * @q: queue holding the block operation
+ * @bio: block operation completed
+ *
+ * This tracepoint indicates there is no further work to do on this
+ * block IO operation @bio.
+ */
 TRACE_EVENT(block_bio_complete,
 
         TP_PROTO(struct request_queue *q, struct bio *bio),
@@ -193,6 +260,14 @@ DECLARE_EVENT_CLASS(block_bio,
                   __entry->nr_sector, __entry->comm)
 );
 
+/**
+ * block_bio_backmerge - merging block operation to the end of an existing operation
+ * @q: queue holding operation
+ * @bio: new block operation to merge
+ *
+ * Merging block request @bio to the end of an existing block request
+ * in queue @q.
+ */
 DEFINE_EVENT(block_bio, block_bio_backmerge,
 
         TP_PROTO(struct request_queue *q, struct bio *bio),
@@ -200,6 +275,14 @@ DEFINE_EVENT(block_bio, block_bio_backmerge,
         TP_ARGS(q, bio)
 );
 
+/**
+ * block_bio_frontmerge - merging block operation to the beginning of an existing operation
+ * @q: queue holding operation
+ * @bio: new block operation to merge
+ *
+ * Merging block IO operation @bio to the beginning of an existing block
+ * operation in queue @q.
+ */
 DEFINE_EVENT(block_bio, block_bio_frontmerge,
 
         TP_PROTO(struct request_queue *q, struct bio *bio),
@@ -207,6 +290,13 @@ DEFINE_EVENT(block_bio, block_bio_frontmerge,
         TP_ARGS(q, bio)
 );
 
+/**
+ * block_bio_queue - putting new block IO operation in queue
+ * @q: queue holding operation
+ * @bio: new block operation
+ *
+ * About to place the block IO operation @bio into queue @q.
+ */
 DEFINE_EVENT(block_bio, block_bio_queue,
 
         TP_PROTO(struct request_queue *q, struct bio *bio),
@@ -243,6 +333,15 @@ DECLARE_EVENT_CLASS(block_get_rq,
                   __entry->nr_sector, __entry->comm)
 );
 
+/**
+ * block_getrq - get a free request entry in queue for block IO operations
+ * @q: queue for operations
+ * @bio: pending block IO operation
+ * @rw: low bit indicates a read (%0) or a write (%1)
+ *
+ * A request struct for queue @q has been allocated to handle the
+ * block IO operation @bio.
+ */
 DEFINE_EVENT(block_get_rq, block_getrq,
 
         TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
@@ -250,6 +349,17 @@ DEFINE_EVENT(block_get_rq, block_getrq,
         TP_ARGS(q, bio, rw)
 );
 
+/**
+ * block_sleeprq - waiting to get a free request entry in queue for block IO operation
+ * @q: queue for operation
+ * @bio: pending block IO operation
+ * @rw: low bit indicates a read (%0) or a write (%1)
+ *
+ * In the case where a request struct cannot be provided for queue @q
+ * the process needs to wait for an request struct to become
+ * available.  This tracepoint event is generated each time the
+ * process goes to sleep waiting for request struct become available.
+ */
 DEFINE_EVENT(block_get_rq, block_sleeprq,
 
         TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
@@ -257,6 +367,14 @@ DEFINE_EVENT(block_get_rq, block_sleeprq,
         TP_ARGS(q, bio, rw)
 );
 
+/**
+ * block_plug - keep operations requests in request queue
+ * @q: request queue to plug
+ *
+ * Plug the request queue @q.  Do not allow block operation requests
+ * to be sent to the device driver. Instead, accumulate requests in
+ * the queue to improve throughput performance of the block device.
+ */
 TRACE_EVENT(block_plug,
 
         TP_PROTO(struct request_queue *q),
@@ -293,6 +411,13 @@ DECLARE_EVENT_CLASS(block_unplug,
         TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
 );
 
+/**
+ * block_unplug_timer - timed release of operations requests in queue to device driver
+ * @q: request queue to unplug
+ *
+ * Unplug the request queue @q because a timer expired and allow block
+ * operation requests to be sent to the device driver.
+ */
 DEFINE_EVENT(block_unplug, block_unplug_timer,
 
         TP_PROTO(struct request_queue *q),
@@ -300,6 +425,13 @@ DEFINE_EVENT(block_unplug, block_unplug_timer,
         TP_ARGS(q)
 );
 
+/**
+ * block_unplug_io - release of operations requests in request queue
+ * @q: request queue to unplug
+ *
+ * Unplug request queue @q because device driver is scheduled to work
+ * on elements in the request queue.
+ */
 DEFINE_EVENT(block_unplug, block_unplug_io,
 
         TP_PROTO(struct request_queue *q),
@@ -307,6 +439,17 @@ DEFINE_EVENT(block_unplug, block_unplug_io,
         TP_ARGS(q)
 );
 
+/**
+ * block_split - split a single bio struct into two bio structs
+ * @q: queue containing the bio
+ * @bio: block operation being split
+ * @new_sector: The starting sector for the new bio
+ *
+ * The bio request @bio in request queue @q needs to be split into two
+ * bio requests. The newly created @bio request starts at
+ * @new_sector. This split may be required due to hardware limitation
+ * such as operation crossing device boundaries in a RAID system.
+ */
 TRACE_EVENT(block_split,
 
         TP_PROTO(struct request_queue *q, struct bio *bio,
@@ -337,6 +480,16 @@ TRACE_EVENT(block_split,
                   __entry->comm)
 );
 
+/**
+ * block_remap - map request for a partition to the raw device
+ * @q: queue holding the operation
+ * @bio: revised operation
+ * @dev: device for the operation
+ * @from: original sector for the operation
+ *
+ * An operation for a partition on a block device has been mapped to the
+ * raw block device.
+ */
 TRACE_EVENT(block_remap,
 
         TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
@@ -370,6 +523,17 @@ TRACE_EVENT(block_remap,
                   (unsigned long long)__entry->old_sector)
 );
 
+/**
+ * block_rq_remap - map request for a block operation request
+ * @q: queue holding the operation
+ * @rq: block IO operation request
+ * @dev: device for the operation
+ * @from: original sector for the operation
+ *
+ * The block operation request @rq in @q has been remapped.  The block
+ * operation request @rq holds the current information and @from hold
+ * the original sector.
+ */
 TRACE_EVENT(block_rq_remap,
 
         TP_PROTO(struct request_queue *q, struct request *rq, dev_t dev,