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authorLinus Torvalds <torvalds@linux-foundation.org>2010-11-27 07:17:50 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2010-11-27 07:17:50 +0900
commit78daa87b1d332e4ac963c793a4157533d57501c7 (patch)
treec133840b219a446c11fa2391bb0d887e71f5809f /drivers
parentd4d2ad948e9a9c316e72fdc09d7490dfda4773da (diff)
parentbbe425cd9ae83eacd0c9f09df2bf56dc911a54cd (diff)
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Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cciss: fix build for PROC_FS disabled block: fix amiga and atari floppy driver compile warning blk-throttle: Fix calculation of max number of WRITES to be dispatched ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() xen/blkfront: cope with backend that fail empty BLKIF_OP_WRITE_BARRIER requests xen/blkfront: Implement FUA with BLKIF_OP_WRITE_BARRIER xen/blkfront: change blk_shadow.request to proper pointer xen/blkfront: map REQ_FLUSH into a full barrier
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/amiflop.c2
-rw-r--r--drivers/block/ataflop.c2
-rw-r--r--drivers/block/cciss.c3
-rw-r--r--drivers/block/xen-blkfront.c55
4 files changed, 36 insertions, 26 deletions
diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index a1725e6488d..7888501ad9e 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1341,7 +1341,7 @@ static struct request *set_next_request(void)
{
struct request_queue *q;
int cnt = FD_MAX_UNITS;
- struct request *rq;
+ struct request *rq = NULL;
/* Find next queue we can dispatch from */
fdc_queue = fdc_queue + 1;
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 4e4cc6c828c..605a67e40bb 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -1399,7 +1399,7 @@ static struct request *set_next_request(void)
{
struct request_queue *q;
int old_pos = fdc_queue;
- struct request *rq;
+ struct request *rq = NULL;
do {
q = unit[fdc_queue].disk->queue;
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index a67d0a611a8..f291587d753 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -66,6 +66,7 @@ MODULE_VERSION("3.6.26");
MODULE_LICENSE("GPL");
static DEFINE_MUTEX(cciss_mutex);
+static struct proc_dir_entry *proc_cciss;
#include "cciss_cmd.h"
#include "cciss.h"
@@ -363,8 +364,6 @@ static const char *raid_label[] = { "0", "4", "1(1+0)", "5", "5+1", "ADG",
#define ENG_GIG_FACTOR (ENG_GIG/512)
#define ENGAGE_SCSI "engage scsi"
-static struct proc_dir_entry *proc_cciss;
-
static void cciss_seq_show_header(struct seq_file *seq)
{
ctlr_info_t *h = seq->private;
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 255035cfc88..4f9e22f2913 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -65,7 +65,7 @@ enum blkif_state {
struct blk_shadow {
struct blkif_request req;
- unsigned long request;
+ struct request *request;
unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
};
@@ -136,7 +136,7 @@ static void add_id_to_freelist(struct blkfront_info *info,
unsigned long id)
{
info->shadow[id].req.id = info->shadow_free;
- info->shadow[id].request = 0;
+ info->shadow[id].request = NULL;
info->shadow_free = id;
}
@@ -245,14 +245,11 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
}
/*
- * blkif_queue_request
+ * Generate a Xen blkfront IO request from a blk layer request. Reads
+ * and writes are handled as expected. Since we lack a loose flush
+ * request, we map flushes into a full ordered barrier.
*
- * request block io
- *
- * id: for guest use only.
- * operation: BLKIF_OP_{READ,WRITE,PROBE}
- * buffer: buffer to read/write into. this should be a
- * virtual address in the guest os.
+ * @req: a request struct
*/
static int blkif_queue_request(struct request *req)
{
@@ -281,7 +278,7 @@ static int blkif_queue_request(struct request *req)
/* Fill out a communications ring structure. */
ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
id = get_id_from_freelist(info);
- info->shadow[id].request = (unsigned long)req;
+ info->shadow[id].request = req;
ring_req->id = id;
ring_req->sector_number = (blkif_sector_t)blk_rq_pos(req);
@@ -290,6 +287,18 @@ static int blkif_queue_request(struct request *req)
ring_req->operation = rq_data_dir(req) ?
BLKIF_OP_WRITE : BLKIF_OP_READ;
+ if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
+ /*
+ * Ideally we could just do an unordered
+ * flush-to-disk, but all we have is a full write
+ * barrier at the moment. However, a barrier write is
+ * a superset of FUA, so we can implement it the same
+ * way. (It's also a FLUSH+FUA, since it is
+ * guaranteed ordered WRT previous writes.)
+ */
+ ring_req->operation = BLKIF_OP_WRITE_BARRIER;
+ }
+
ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg);
BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
@@ -634,7 +643,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
bret = RING_GET_RESPONSE(&info->ring, i);
id = bret->id;
- req = (struct request *)info->shadow[id].request;
+ req = info->shadow[id].request;
blkif_completion(&info->shadow[id]);
@@ -647,6 +656,16 @@ 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;
+ }
+ if (unlikely(bret->status == BLKIF_RSP_ERROR &&
+ info->shadow[id].req.nr_segments == 0)) {
+ printk(KERN_WARNING "blkfront: %s: empty write barrier op failed\n",
+ info->gd->disk_name);
+ error = -EOPNOTSUPP;
+ }
+ if (unlikely(error)) {
+ if (error == -EOPNOTSUPP)
+ error = 0;
info->feature_flush = 0;
xlvbd_flush(info);
}
@@ -899,7 +918,7 @@ static int blkif_recover(struct blkfront_info *info)
/* Stage 3: Find pending requests and requeue them. */
for (i = 0; i < BLK_RING_SIZE; i++) {
/* Not in use? */
- if (copy[i].request == 0)
+ if (!copy[i].request)
continue;
/* Grab a request slot and copy shadow state into it. */
@@ -916,9 +935,7 @@ static int blkif_recover(struct blkfront_info *info)
req->seg[j].gref,
info->xbdev->otherend_id,
pfn_to_mfn(info->shadow[req->id].frame[j]),
- rq_data_dir(
- (struct request *)
- info->shadow[req->id].request));
+ rq_data_dir(info->shadow[req->id].request));
info->shadow[req->id].req = *req;
info->ring.req_prod_pvt++;
@@ -1067,14 +1084,8 @@ static void blkfront_connect(struct blkfront_info *info)
*/
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
+ info->feature_flush = REQ_FLUSH | REQ_FUA;
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {