src/patches/suse-2.6.27.31/patches.fixes/block-use-bio_has_data

   1 From 0f96bb8e2923065d58d89c5c82c9f37ad1f18404 Mon Sep 17 00:00:00 2001
   2 From: Hannes Reinecke <hare@suse.de>
   3 Date: Thu, 23 Oct 2008 13:42:06 +0200
   4 Subject: [PATCH] Implement bio_has_data()
   5
   6 Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
   7 Signed-off-by: Hannes Reinecke <hare@suse.de>
   8 ---
   9  block/blk-core.c       |   21 +++++++--------------
  10  include/linux/bio.h    |   14 +++++++++++---
  11  include/linux/blkdev.h |    2 +-
  12  mm/bounce.c            |    2 +-
  13  4 files changed, 20 insertions(+), 19 deletions(-)
  14
  15 --- a/block/blk-core.c
  16 +++ b/block/blk-core.c
  17 @@ -624,10 +624,6 @@ blk_alloc_request(struct request_queue *
  18
  19         blk_rq_init(q, rq);
  20
  21 -       /*
  22 -        * first three bits are identical in rq->cmd_flags and bio->bi_rw,
  23 -        * see bio.h and blkdev.h
  24 -        */
  25         rq->cmd_flags = rw | REQ_ALLOCED;
  26
  27         if (priv) {
  28 @@ -1490,10 +1486,7 @@ void submit_bio(int rw, struct bio *bio)
  29          * If it's a regular read/write or a barrier with data attached,
  30          * go through the normal accounting stuff before submission.
  31          */
  32 -       if (!bio_empty_barrier(bio)) {
  33 -
  34 -               BIO_BUG_ON(!bio->bi_size);
  35 -               BIO_BUG_ON(!bio->bi_io_vec);
  36 +       if (bio_has_data(bio)) {
  37
  38                 if (rw & WRITE) {
  39                         count_vm_events(PGPGOUT, count);
  40 @@ -1888,7 +1881,7 @@ static int blk_end_io(struct request *rq
  41         struct request_queue *q = rq->q;
  42         unsigned long flags = 0UL;
  43
  44 -       if (blk_fs_request(rq) || blk_pc_request(rq)) {
  45 +       if (bio_has_data(rq->bio)) {
  46                 if (__end_that_request_first(rq, error, nr_bytes))
  47                         return 1;
  48
  49 @@ -1946,10 +1939,9 @@ EXPORT_SYMBOL_GPL(blk_end_request);
  50   **/
  51  int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
  52  {
  53 -       if (blk_fs_request(rq) || blk_pc_request(rq)) {
  54 -               if (__end_that_request_first(rq, error, nr_bytes))
  55 -                       return 1;
  56 -       }
  57 +       if (bio_has_data(rq->bio) &&
  58 +           __end_that_request_first(rq, error, nr_bytes))
  59 +               return 1;
  60
  61         add_disk_randomness(rq->rq_disk);
  62
  63 @@ -2016,7 +2008,8 @@ EXPORT_SYMBOL_GPL(blk_end_request_callba
  64  void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
  65                      struct bio *bio)
  66  {
  67 -       /* first two bits are identical in rq->cmd_flags and bio->bi_rw */
  68 +       /* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
  69 +          we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
  70         rq->cmd_flags |= (bio->bi_rw & 3);
  71
  72         rq->nr_phys_segments = bio_phys_segments(q, bio);
  73 --- a/include/linux/bio.h
  74 +++ b/include/linux/bio.h
  75 @@ -157,8 +157,8 @@ struct bio {
  76   * bit 3 -- fail fast, don't want low level driver retries
  77   * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
  78   */
  79 -#define BIO_RW         0
  80 -#define BIO_RW_AHEAD   1
  81 +#define BIO_RW         0       /* Must match RW in req flags (blkdev.h) */
  82 +#define BIO_RW_AHEAD   1       /* Must match FAILFAST in req flags */
  83  #define BIO_RW_BARRIER 2
  84  #define BIO_RW_FAILFAST        3
  85  #define BIO_RW_SYNC    4
  86 @@ -192,7 +192,7 @@ struct bio {
  87  #define bio_failfast(bio)      ((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
  88  #define bio_rw_ahead(bio)      ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
  89  #define bio_rw_meta(bio)       ((bio)->bi_rw & (1 << BIO_RW_META))
  90 -#define bio_empty_barrier(bio) (bio_barrier(bio) && !(bio)->bi_size)
  91 +#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio))
  92
  93  static inline unsigned int bio_cur_sectors(struct bio *bio)
  94  {
  95 @@ -452,6 +452,14 @@ static inline char *__bio_kmap_irq(struc
  96         __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
  97  #define bio_kunmap_irq(buf,flags)      __bio_kunmap_irq(buf, flags)
  98
  99 +/*
 100 + * Check whether this bio carries any data or not. A NULL bio is allowed.
 101 + */
 102 +static inline int bio_has_data(struct bio *bio)
 103 +{
 104 +       return bio && bio->bi_io_vec != NULL;
 105 +}
 106 +
 107  #if defined(CONFIG_BLK_DEV_INTEGRITY)
 108
 109  #define bip_vec_idx(bip, idx)  (&(bip->bip_vec[(idx)]))
 110 --- a/include/linux/blkdev.h
 111 +++ b/include/linux/blkdev.h
 112 @@ -84,7 +84,7 @@ enum {
 113  };
 114
 115  /*
 116 - * request type modified bits. first three bits match BIO_RW* bits, important
 117 + * request type modified bits. first two bits match BIO_RW* bits, important
 118   */
 119  enum rq_flag_bits {
 120         __REQ_RW,               /* not set, read. set, write */
 121 --- a/mm/bounce.c
 122 +++ b/mm/bounce.c
 123 @@ -267,7 +267,7 @@ void blk_queue_bounce(struct request_que
 124         /*
 125          * Data-less bio, nothing to bounce
 126          */
 127 -       if (bio_empty_barrier(*bio_orig))
 128 +       if (!bio_has_data(*bio_orig))
 129                 return;
 130
 131         /*