block: remove REQ_HARDBARRIER
Christoph Hellwig [Wed, 10 Nov 2010 13:54:09 +0000 (14:54 +0100)]
REQ_HARDBARRIER is dead now, so remove the leftovers.  What's left
at this point is:

 - various checks inside the block layer.
 - sanity checks in bio based drivers.
 - now unused bio_empty_barrier helper.
 - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
   but Xen really needs to sort out it's barrier situaton.
 - setting of ordered tags in uas - dead code copied from old scsi
   drivers.
 - scsi different retry for barriers - it's dead and should have been
   removed when flushes were converted to FS requests.
 - blktrace handling of barriers - removed.  Someone who knows blktrace
   better should add support for REQ_FLUSH and REQ_FUA, though.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block/blk-core.c
block/elevator.c
drivers/block/aoe/aoeblk.c
drivers/block/loop.c
drivers/block/xen-blkfront.c
drivers/scsi/scsi_error.c
drivers/usb/storage/uas.c
include/linux/bio.h
include/linux/blk_types.h
include/linux/blkdev.h
kernel/trace/blktrace.c

index 17fcb83..4ce953f 100644 (file)
@@ -1194,13 +1194,6 @@ static int __make_request(struct request_queue *q, struct bio *bio)
        int where = ELEVATOR_INSERT_SORT;
        int rw_flags;
 
-       /* REQ_HARDBARRIER is no more */
-       if (WARN_ONCE(bio->bi_rw & REQ_HARDBARRIER,
-               "block: HARDBARRIER is deprecated, use FLUSH/FUA instead\n")) {
-               bio_endio(bio, -EOPNOTSUPP);
-               return 0;
-       }
-
        /*
         * low level driver can indicate that it wants pages above a
         * certain limit bounced to low memory (ie for highmem, or even
index 282e830..2569512 100644 (file)
@@ -429,7 +429,7 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
        q->nr_sorted--;
 
        boundary = q->end_sector;
-       stop_flags = REQ_SOFTBARRIER | REQ_HARDBARRIER | REQ_STARTED;
+       stop_flags = REQ_SOFTBARRIER | REQ_STARTED;
        list_for_each_prev(entry, &q->queue_head) {
                struct request *pos = list_entry_rq(entry);
 
@@ -691,7 +691,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
 void __elv_add_request(struct request_queue *q, struct request *rq, int where,
                       int plug)
 {
-       if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
+       if (rq->cmd_flags & REQ_SOFTBARRIER) {
                /* barriers are scheduling boundary, update end_sector */
                if (rq->cmd_type == REQ_TYPE_FS ||
                    (rq->cmd_flags & REQ_DISCARD)) {
index 541e188..528f631 100644 (file)
@@ -180,9 +180,6 @@ aoeblk_make_request(struct request_queue *q, struct bio *bio)
                BUG();
                bio_endio(bio, -ENXIO);
                return 0;
-       } else if (bio->bi_rw & REQ_HARDBARRIER) {
-               bio_endio(bio, -EOPNOTSUPP);
-               return 0;
        } else if (bio->bi_io_vec == NULL) {
                printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
                BUG();
index 1e5284e..7ea0bea 100644 (file)
@@ -481,12 +481,6 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
        if (bio_rw(bio) == WRITE) {
                struct file *file = lo->lo_backing_file;
 
-               /* REQ_HARDBARRIER is deprecated */
-               if (bio->bi_rw & REQ_HARDBARRIER) {
-                       ret = -EOPNOTSUPP;
-                       goto out;
-               }
-
                if (bio->bi_rw & REQ_FLUSH) {
                        ret = vfs_fsync(file, 0);
                        if (unlikely(ret && ret != -EINVAL)) {
index 06e2812..255035c 100644 (file)
@@ -289,8 +289,6 @@ 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_HARDBARRIER)
-               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);
index 1de30eb..f3cf924 100644 (file)
@@ -320,19 +320,11 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
                                    "changed. The Linux SCSI layer does not "
                                    "automatically adjust these parameters.\n");
 
-               if (scmd->request->cmd_flags & REQ_HARDBARRIER)
-                       /*
-                        * barrier requests should always retry on UA
-                        * otherwise block will get a spurious error
-                        */
-                       return NEEDS_RETRY;
-               else
-                       /*
-                        * for normal (non barrier) commands, pass the
-                        * UA upwards for a determination in the
-                        * completion functions
-                        */
-                       return SUCCESS;
+               /*
+                * Pass the UA upwards for a determination in the completion
+                * functions.
+                */
+               return SUCCESS;
 
                /* these three are not supported */
        case COPY_ABORTED:
index 2054b1e..d126819 100644 (file)
@@ -331,10 +331,7 @@ static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 
        iu->iu_id = IU_ID_COMMAND;
        iu->tag = cpu_to_be16(stream_id);
-       if (sdev->ordered_tags && (cmnd->request->cmd_flags & REQ_HARDBARRIER))
-               iu->prio_attr = UAS_ORDERED_TAG;
-       else
-               iu->prio_attr = UAS_SIMPLE_TAG;
+       iu->prio_attr = UAS_SIMPLE_TAG;
        iu->len = len;
        int_to_scsilun(sdev->lun, &iu->lun);
        memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
index ba67999..35dcdb3 100644 (file)
 #define bio_offset(bio)                bio_iovec((bio))->bv_offset
 #define bio_segments(bio)      ((bio)->bi_vcnt - (bio)->bi_idx)
 #define bio_sectors(bio)       ((bio)->bi_size >> 9)
-#define bio_empty_barrier(bio) \
-       ((bio->bi_rw & REQ_HARDBARRIER) && \
-        !bio_has_data(bio) && \
-        !(bio->bi_rw & REQ_DISCARD))
 
 static inline unsigned int bio_cur_bytes(struct bio *bio)
 {
index 0437ab6..46ad519 100644 (file)
@@ -122,7 +122,6 @@ enum rq_flag_bits {
        __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
        __REQ_FAILFAST_DRIVER,  /* no driver retries of driver errors */
 
-       __REQ_HARDBARRIER,      /* may not be passed by drive either */
        __REQ_SYNC,             /* request is sync (sync write or read) */
        __REQ_META,             /* metadata io request */
        __REQ_DISCARD,          /* request to discard sectors */
@@ -159,7 +158,6 @@ enum rq_flag_bits {
 #define REQ_FAILFAST_DEV       (1 << __REQ_FAILFAST_DEV)
 #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT)
 #define REQ_FAILFAST_DRIVER    (1 << __REQ_FAILFAST_DRIVER)
-#define REQ_HARDBARRIER                (1 << __REQ_HARDBARRIER)
 #define REQ_SYNC               (1 << __REQ_SYNC)
 #define REQ_META               (1 << __REQ_META)
 #define REQ_DISCARD            (1 << __REQ_DISCARD)
@@ -168,8 +166,8 @@ enum rq_flag_bits {
 #define REQ_FAILFAST_MASK \
        (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 #define REQ_COMMON_MASK \
-       (REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
-        REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+       (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \
+        REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 #define REQ_CLONE_MASK         REQ_COMMON_MASK
 
 #define REQ_UNPLUG             (1 << __REQ_UNPLUG)
index 5027a59..aae86fd 100644 (file)
@@ -552,8 +552,7 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync)
  * it already be started by driver.
  */
 #define RQ_NOMERGE_FLAGS       \
-       (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
-        REQ_FLUSH | REQ_FUA)
+       (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
 #define rq_mergeable(rq)       \
        (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
         (((rq)->cmd_flags & REQ_DISCARD) || \
index bc251ed..7b8ec02 100644 (file)
@@ -168,7 +168,6 @@ static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
 static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
                                 BLK_TC_ACT(BLK_TC_WRITE) };
 
-#define BLK_TC_HARDBARRIER     BLK_TC_BARRIER
 #define BLK_TC_RAHEAD          BLK_TC_AHEAD
 
 /* The ilog2() calls fall out because they're constant */
@@ -196,7 +195,6 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
                return;
 
        what |= ddir_act[rw & WRITE];
-       what |= MASK_TC_BIT(rw, HARDBARRIER);
        what |= MASK_TC_BIT(rw, SYNC);
        what |= MASK_TC_BIT(rw, RAHEAD);
        what |= MASK_TC_BIT(rw, META);
@@ -1807,8 +1805,6 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
 
        if (rw & REQ_RAHEAD)
                rwbs[i++] = 'A';
-       if (rw & REQ_HARDBARRIER)
-               rwbs[i++] = 'B';
        if (rw & REQ_SYNC)
                rwbs[i++] = 'S';
        if (rw & REQ_META)