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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 17:07:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 17:07:18 -0700
commita2887097f25cd38cadfc11d10769e2b349fb5eca (patch)
treecd4adcb305365d6ba9acd2c02d4eb9d0125c6f8d /drivers/block/xen-blkfront.c
parent8abfc6e7a45eb74e51904bbae676fae008b11366 (diff)
parent005a1d15f5a6b2bb4ada80349513effbf22b4588 (diff)
downloadlinux-rt-a2887097f25cd38cadfc11d10769e2b349fb5eca.tar.gz
Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...
Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c54
1 files changed, 20 insertions, 34 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 3ff06f475eef..4b33a18c32e0 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -96,7 +96,7 @@ struct blkfront_info
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
@@ -419,26 +419,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
@@ -517,7 +503,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
@@ -663,8 +649,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
@@ -1077,20 +1063,20 @@ static void blkfront_connect(struct blkfront_info *info)
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
+ * If there are barriers, then we use flush.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+
+ /*
+ * The driver doesn't properly handled empty flushes, so
+ * lets disable barrier support for now.
+ */
+#if 0
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
+#endif
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {