---

yaml
---
r: 17083
b: refs/heads/master
c: ff856ba
h: refs/heads/master
i:
  17081: 94597b8
  17079: 762e77b
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 356cebea1123804e4aa85b43ab39bbd0ac8e667c
+refs/heads/master: ff856bad67cb65cb4dc4ef88b808804fc4265782

trunk/block/elevator.c

@@ -64,7 +64,7 @@ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 }
 EXPORT_SYMBOL(elv_rq_merge_ok);
 
-static inline int elv_try_merge(struct request *__rq, struct bio *bio)
+inline int elv_try_merge(struct request *__rq, struct bio *bio)
 {
 	int ret = ELEVATOR_NO_MERGE;
 
@@ -80,6 +80,7 @@ static inline int elv_try_merge(struct request *__rq, struct bio *bio)
 
 	return ret;
 }
+EXPORT_SYMBOL(elv_try_merge);
 
 static struct elevator_type *elevator_find(const char *name)
 {

trunk/block/ll_rw_blk.c

@@ -26,6 +26,9 @@
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
 
 /*
  * for max sense size
@@ -61,13 +64,15 @@ static wait_queue_head_t congestion_wqh[2] = {
 /*
  * Controlling structure to kblockd
  */
-static struct workqueue_struct *kblockd_workqueue; 
+static struct workqueue_struct *kblockd_workqueue;
 
 unsigned long blk_max_low_pfn, blk_max_pfn;
 
 EXPORT_SYMBOL(blk_max_low_pfn);
 EXPORT_SYMBOL(blk_max_pfn);
 
+static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
+
 /* Amount of time in which a process may batch requests */
 #define BLK_BATCH_TIME	(HZ/50UL)
 
@@ -206,6 +211,13 @@ void blk_queue_merge_bvec(request_queue_t *q, merge_bvec_fn *mbfn)
 
 EXPORT_SYMBOL(blk_queue_merge_bvec);
 
+void blk_queue_softirq_done(request_queue_t *q, softirq_done_fn *fn)
+{
+	q->softirq_done_fn = fn;
+}
+
+EXPORT_SYMBOL(blk_queue_softirq_done);
+
 /**
  * blk_queue_make_request - define an alternate make_request function for a device
  * @q:  the request queue for the device to be affected
@@ -269,6 +281,7 @@ EXPORT_SYMBOL(blk_queue_make_request);
 static inline void rq_init(request_queue_t *q, struct request *rq)
 {
 	INIT_LIST_HEAD(&rq->queuelist);
+	INIT_LIST_HEAD(&rq->donelist);
 
 	rq->errors = 0;
 	rq->rq_status = RQ_ACTIVE;
@@ -285,6 +298,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq)
 	rq->sense = NULL;
 	rq->end_io = NULL;
 	rq->end_io_data = NULL;
+	rq->completion_data = NULL;
 }
 
 /**
@@ -2734,6 +2748,30 @@ static inline int attempt_front_merge(request_queue_t *q, struct request *rq)
 	return 0;
 }
 
+/**
+ * blk_attempt_remerge  - attempt to remerge active head with next request
+ * @q:    The &request_queue_t belonging to the device
+ * @rq:   The head request (usually)
+ *
+ * Description:
+ *    For head-active devices, the queue can easily be unplugged so quickly
+ *    that proper merging is not done on the front request. This may hurt
+ *    performance greatly for some devices. The block layer cannot safely
+ *    do merging on that first request for these queues, but the driver can
+ *    call this function and make it happen any way. Only the driver knows
+ *    when it is safe to do so.
+ **/
+void blk_attempt_remerge(request_queue_t *q, struct request *rq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	attempt_back_merge(q, rq);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+EXPORT_SYMBOL(blk_attempt_remerge);
+
 static void init_request_from_bio(struct request *req, struct bio *bio)
 {
 	req->flags |= REQ_CMD;
@@ -3261,6 +3299,87 @@ int end_that_request_chunk(struct request *req, int uptodate, int nr_bytes)
 
 EXPORT_SYMBOL(end_that_request_chunk);
 
+/*
+ * splice the completion data to a local structure and hand off to
+ * process_completion_queue() to complete the requests
+ */
+static void blk_done_softirq(struct softirq_action *h)
+{
+	struct list_head *cpu_list;
+	LIST_HEAD(local_list);
+
+	local_irq_disable();
+	cpu_list = &__get_cpu_var(blk_cpu_done);
+	list_splice_init(cpu_list, &local_list);
+	local_irq_enable();
+
+	while (!list_empty(&local_list)) {
+		struct request *rq = list_entry(local_list.next, struct request, donelist);
+
+		list_del_init(&rq->donelist);
+		rq->q->softirq_done_fn(rq);
+	}
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
+			  void *hcpu)
+{
+	/*
+	 * If a CPU goes away, splice its entries to the current CPU
+	 * and trigger a run of the softirq
+	 */
+	if (action == CPU_DEAD) {
+		int cpu = (unsigned long) hcpu;
+
+		local_irq_disable();
+		list_splice_init(&per_cpu(blk_cpu_done, cpu),
+				 &__get_cpu_var(blk_cpu_done));
+		raise_softirq_irqoff(BLOCK_SOFTIRQ);
+		local_irq_enable();
+	}
+
+	return NOTIFY_OK;
+}
+
+
+static struct notifier_block __devinitdata blk_cpu_notifier = {
+	.notifier_call	= blk_cpu_notify,
+};
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+/**
+ * blk_complete_request - end I/O on a request
+ * @req:      the request being processed
+ *
+ * Description:
+ *     Ends all I/O on a request. It does not handle partial completions,
+ *     unless the driver actually implements this in its completionc callback
+ *     through requeueing. Theh actual completion happens out-of-order,
+ *     through a softirq handler. The user must have registered a completion
+ *     callback through blk_queue_softirq_done().
+ **/
+
+void blk_complete_request(struct request *req)
+{
+	struct list_head *cpu_list;
+	unsigned long flags;
+
+	BUG_ON(!req->q->softirq_done_fn);
+
+	local_irq_save(flags);
+
+	cpu_list = &__get_cpu_var(blk_cpu_done);
+	list_add_tail(&req->donelist, cpu_list);
+	raise_softirq_irqoff(BLOCK_SOFTIRQ);
+
+	local_irq_restore(flags);
+}
+
+EXPORT_SYMBOL(blk_complete_request);
+
 /*
  * queue lock must be held
  */
@@ -3339,6 +3458,8 @@ EXPORT_SYMBOL(kblockd_flush);
 
 int __init blk_dev_init(void)
 {
+	int i;
+
 	kblockd_workqueue = create_workqueue("kblockd");
 	if (!kblockd_workqueue)
 		panic("Failed to create kblockd\n");
@@ -3352,6 +3473,14 @@ int __init blk_dev_init(void)
 	iocontext_cachep = kmem_cache_create("blkdev_ioc",
 			sizeof(struct io_context), 0, SLAB_PANIC, NULL, NULL);
 
+	for (i = 0; i < NR_CPUS; i++)
+		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
+
+	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
+#ifdef CONFIG_HOTPLUG_CPU
+	register_cpu_notifier(&blk_cpu_notifier);
+#endif
+
 	blk_max_low_pfn = max_low_pfn;
 	blk_max_pfn = max_pfn;
 

trunk/block/scsi_ioctl.c

@@ -190,21 +190,16 @@ static int verify_command(struct file *file, unsigned char *cmd)
 		safe_for_write(GPCMD_SET_STREAMING),
 	};
 	unsigned char type = cmd_type[cmd[0]];
-	int has_write_perm = 0;
 
 	/* Anybody who can open the device can do a read-safe command */
 	if (type & CMD_READ_SAFE)
 		return 0;
 
-	/*
-	 * file can be NULL from ioctl_by_bdev()...
-	 */
-	if (file)
-		has_write_perm = file->f_mode & FMODE_WRITE;
-
 	/* Write-safe commands just require a writable open.. */
-	if ((type & CMD_WRITE_SAFE) && has_write_perm)
-		return 0;
+	if (type & CMD_WRITE_SAFE) {
+		if (file->f_mode & FMODE_WRITE)
+			return 0;
+	}
 
 	/* And root can do any command.. */
 	if (capable(CAP_SYS_RAWIO))

trunk/drivers/ide/ide-cd.c

@@ -1332,6 +1332,8 @@ static ide_startstop_t cdrom_start_read (ide_drive_t *drive, unsigned int block)
 	if (cdrom_read_from_buffer(drive))
 		return ide_stopped;
 
+	blk_attempt_remerge(drive->queue, rq);
+
 	/* Clear the local sector buffer. */
 	info->nsectors_buffered = 0;
 
@@ -1872,6 +1874,14 @@ static ide_startstop_t cdrom_start_write(ide_drive_t *drive, struct request *rq)
 		return ide_stopped;
 	}
 
+	/*
+	 * for dvd-ram and such media, it's a really big deal to get
+	 * big writes all the time. so scour the queue and attempt to
+	 * remerge requests, often the plugging will not have had time
+	 * to do this properly
+	 */
+	blk_attempt_remerge(drive->queue, rq);
+
 	info->nsectors_buffered = 0;
 
 	/* use dma, if possible. we don't need to check more, since we

trunk/fs/bio.c

@@ -126,7 +126,6 @@ static void bio_fs_destructor(struct bio *bio)
 inline void bio_init(struct bio *bio)
 {
 	bio->bi_next = NULL;
-	bio->bi_bdev = NULL;
 	bio->bi_flags = 1 << BIO_UPTODATE;
 	bio->bi_rw = 0;
 	bio->bi_vcnt = 0;

trunk/include/linux/blkdev.h

@@ -118,9 +118,9 @@ struct request_list {
  * try to put the fields that are referenced together in the same cacheline
  */
 struct request {
-	struct list_head queuelist; /* looking for ->queue? you must _not_
-				     * access it directly, use
-				     * blkdev_dequeue_request! */
+	struct list_head queuelist;
+	struct list_head donelist;
+
 	unsigned long flags;		/* see REQ_ bits below */
 
 	/* Maintain bio traversal state for part by part I/O submission.
@@ -141,6 +141,7 @@ struct request {
 	struct bio *biotail;
 
 	void *elevator_private;
+	void *completion_data;
 
 	unsigned short ioprio;
 
@@ -291,6 +292,7 @@ typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
 typedef void (activity_fn) (void *data, int rw);
 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
 typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
+typedef void (softirq_done_fn)(struct request *);
 
 enum blk_queue_state {
 	Queue_down,
@@ -332,6 +334,7 @@ struct request_queue
 	activity_fn		*activity_fn;
 	issue_flush_fn		*issue_flush_fn;
 	prepare_flush_fn	*prepare_flush_fn;
+	softirq_done_fn		*softirq_done_fn;
 
 	/*
 	 * Dispatch queue sorting
@@ -592,6 +595,7 @@ extern void generic_make_request(struct bio *bio);
 extern void blk_put_request(struct request *);
 extern void __blk_put_request(request_queue_t *, struct request *);
 extern void blk_end_sync_rq(struct request *rq, int error);
+extern void blk_attempt_remerge(request_queue_t *, struct request *);
 extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
 extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
 extern void blk_requeue_request(request_queue_t *, struct request *);
@@ -645,6 +649,17 @@ extern int end_that_request_first(struct request *, int, int);
 extern int end_that_request_chunk(struct request *, int, int);
 extern void end_that_request_last(struct request *, int);
 extern void end_request(struct request *req, int uptodate);
+extern void blk_complete_request(struct request *);
+
+static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
+{
+	if (blk_fs_request(rq))
+		return (nr_bytes >= (rq->hard_nr_sectors << 9));
+	else if (blk_pc_request(rq))
+		return nr_bytes >= rq->data_len;
+
+	return 0;
+}
 
 /*
  * end_that_request_first/chunk() takes an uptodate argument. we account
@@ -693,6 +708,7 @@ extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
 extern void blk_queue_dma_alignment(request_queue_t *, int);
+extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
 extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);

trunk/include/linux/elevator.h

@@ -114,6 +114,8 @@ extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);
 extern int elevator_init(request_queue_t *, char *);
 extern void elevator_exit(elevator_t *);
 extern int elv_rq_merge_ok(struct request *, struct bio *);
+extern int elv_try_merge(struct request *, struct bio *);
+extern int elv_try_last_merge(request_queue_t *, struct bio *);
 
 /*
  * Return values from elevator merger

trunk/include/linux/interrupt.h

@@ -112,6 +112,7 @@ enum
 	TIMER_SOFTIRQ,
 	NET_TX_SOFTIRQ,
 	NET_RX_SOFTIRQ,
+	BLOCK_SOFTIRQ,
 	SCSI_SOFTIRQ,
 	TASKLET_SOFTIRQ
 };