string: factorize skip_spaces and export it to be generally available

[safe/jmp/linux-2.6] / block / blk-settings.c

diff --git a/block/blk-settings.c b/block/blk-settings.c
index e0695bc..dd1f1e0 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -8,6 +8,7 @@
 #include <linux/blkdev.h>
 #include <linux/bootmem.h>     /* for max_pfn/max_low_pfn */
 #include <linux/gcd.h>
+#include <linux/jiffies.h>
 
 #include "blk.h"
 
@@ -96,7 +97,11 @@ void blk_set_default_limits(struct queue_limits *lim)
        lim->max_segment_size = MAX_SEGMENT_SIZE;
        lim->max_sectors = BLK_DEF_MAX_SECTORS;
        lim->max_hw_sectors = INT_MAX;
-       lim->max_discard_sectors = SAFE_MAX_SECTORS;
+       lim->max_discard_sectors = 0;
+       lim->discard_granularity = 0;
+       lim->discard_alignment = 0;
+       lim->discard_misaligned = 0;
+       lim->discard_zeroes_data = -1;
        lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
        lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
        lim->alignment_offset = 0;
@@ -141,7 +146,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
        q->nr_batching = BLK_BATCH_REQ;
 
        q->unplug_thresh = 4;           /* hmm */
-       q->unplug_delay = (3 * HZ) / 1000;      /* 3 milliseconds */
+       q->unplug_delay = msecs_to_jiffies(3);  /* 3 milliseconds */
        if (q->unplug_delay == 0)
                q->unplug_delay = 1;
 
@@ -242,7 +247,7 @@ EXPORT_SYMBOL(blk_queue_max_hw_sectors);
 /**
  * blk_queue_max_discard_sectors - set max sectors for a single discard
  * @q:  the request queue for the device
- * @max_discard: maximum number of sectors to discard
+ * @max_discard_sectors: maximum number of sectors to discard
  **/
 void blk_queue_max_discard_sectors(struct request_queue *q,
                unsigned int max_discard_sectors)
@@ -488,6 +493,16 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
 }
 EXPORT_SYMBOL(blk_queue_stack_limits);
 
+static unsigned int lcm(unsigned int a, unsigned int b)
+{
+       if (a && b)
+               return (a * b) / gcd(a, b);
+       else if (b)
+               return b;
+
+       return a;
+}
+
 /**
  * blk_stack_limits - adjust queue_limits for stacked devices
  * @t: the stacking driver limits (top)
@@ -502,6 +517,10 @@ EXPORT_SYMBOL(blk_queue_stack_limits);
 int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
                     sector_t offset)
 {
+       int ret;
+
+       ret = 0;
+
        t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
        t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
        t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn);
@@ -526,12 +545,19 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 
        t->io_min = max(t->io_min, b->io_min);
        t->no_cluster |= b->no_cluster;
+       t->discard_zeroes_data &= b->discard_zeroes_data;
 
        /* Bottom device offset aligned? */
        if (offset &&
            (offset & (b->physical_block_size - 1)) != b->alignment_offset) {
                t->misaligned = 1;
-               return -1;
+               ret = -1;
+       }
+
+       if (offset &&
+           (offset & (b->discard_granularity - 1)) != b->discard_alignment) {
+               t->discard_misaligned = 1;
+               ret = -1;
        }
 
        /* If top has no alignment offset, inherit from bottom */
@@ -539,23 +565,26 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
                t->alignment_offset =
                        b->alignment_offset & (b->physical_block_size - 1);
 
+       if (!t->discard_alignment)
+               t->discard_alignment =
+                       b->discard_alignment & (b->discard_granularity - 1);
+
        /* Top device aligned on logical block boundary? */
        if (t->alignment_offset & (t->logical_block_size - 1)) {
                t->misaligned = 1;
-               return -1;
+               ret = -1;
        }
 
-       /* Find lcm() of optimal I/O size */
-       if (t->io_opt && b->io_opt)
-               t->io_opt = (t->io_opt * b->io_opt) / gcd(t->io_opt, b->io_opt);
-       else if (b->io_opt)
-               t->io_opt = b->io_opt;
+       /* Find lcm() of optimal I/O size and granularity */
+       t->io_opt = lcm(t->io_opt, b->io_opt);
+       t->discard_granularity = lcm(t->discard_granularity,
+                                    b->discard_granularity);
 
        /* Verify that optimal I/O size is a multiple of io_min */
        if (t->io_min && t->io_opt % t->io_min)
-               return -1;
+               ret = -1;
 
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL(blk_stack_limits);