Merge branch 'misc' into release

[pandora-kernel.git] / Documentation / block / barrier.txt

diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt
index 0397151..2c2f24f 100644 (file)
--- a/Documentation/block/barrier.txt
+++ b/Documentation/block/barrier.txt
@@ -25,7 +25,7 @@ of the following three ways.
 i. For devices which have queue depth greater than 1 (TCQ devices) and
 support ordered tags, block layer can just issue the barrier as an
 ordered request and the lower level driver, controller and drive
-itself are responsible for making sure that the ordering contraint is
+itself are responsible for making sure that the ordering constraint is
 met.  Most modern SCSI controllers/drives should support this.
 
 NOTE: SCSI ordered tag isn't currently used due to limitation in the
@@ -42,7 +42,7 @@ iii. Devices which have queue depth of 1.  This is a degenerate case
 of ii.  Just keeping issue order suffices.  Ancient SCSI
 controllers/drives and IDE drives are in this category.
 
-2. Forced flushing to physcial medium
+2. Forced flushing to physical medium
 
 Again, if you're not gonna do synchronization with disk drives (dang,
 it sounds even more appealing now!), the reason you use I/O barriers
@@ -56,7 +56,7 @@ There are four cases,
 i. No write-back cache.  Keeping requests ordered is enough.
 
 ii. Write-back cache but no flush operation.  There's no way to
-gurantee physical-medium commit order.  This kind of devices can't to
+guarantee physical-medium commit order.  This kind of devices can't to
 I/O barriers.
 
 iii. Write-back cache and flush operation but no FUA (forced unit
@@ -79,36 +79,26 @@ and how to prepare flush requests.  Note that the term 'ordered' is
 used to indicate the whole sequence of performing barrier requests
 including draining and flushing.
 
-typedef void (prepare_flush_fn)(request_queue_t *q, struct request *rq);
+typedef void (prepare_flush_fn)(struct request_queue *q, struct request *rq);
 
-int blk_queue_ordered(request_queue_t *q, unsigned ordered,
-                     prepare_flush_fn *prepare_flush_fn,
-                     unsigned gfp_mask);
-
-int blk_queue_ordered_locked(request_queue_t *q, unsigned ordered,
-                            prepare_flush_fn *prepare_flush_fn,
-                            unsigned gfp_mask);
-
-The only difference between the two functions is whether or not the
-caller is holding q->queue_lock on entry.  The latter expects the
-caller is holding the lock.
+int blk_queue_ordered(struct request_queue *q, unsigned ordered,
+                     prepare_flush_fn *prepare_flush_fn);
 
 @q                     : the queue in question
 @ordered               : the ordered mode the driver/device supports
 @prepare_flush_fn      : this function should prepare @rq such that it
                          flushes cache to physical medium when executed
-@gfp_mask              : gfp_mask used when allocating data structures
-                         for ordered processing
 
 For example, SCSI disk driver's prepare_flush_fn looks like the
 following.
 
-static void sd_prepare_flush(request_queue_t *q, struct request *rq)
+static void sd_prepare_flush(struct request_queue *q, struct request *rq)
 {
        memset(rq->cmd, 0, sizeof(rq->cmd));
-       rq->flags |= REQ_BLOCK_PC;
+       rq->cmd_type = REQ_TYPE_BLOCK_PC;
        rq->timeout = SD_TIMEOUT;
        rq->cmd[0] = SYNCHRONIZE_CACHE;
+       rq->cmd_len = 10;
 }
 
 The following seven ordered modes are supported.  The following table