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author | Mike Christie <michaelc@cs.wisc.edu> | 2005-12-05 02:37:06 -0600 |
---|---|---|
committer | James Bottomley <jejb@mulgrave.(none)> | 2005-12-15 15:11:40 -0800 |
commit | defd94b75409b983f94548ea2f52ff5787ddb848 (patch) | |
tree | 0138b2dae748de88edaee4da23431f1a9dd347a1 /fs/bio.c | |
parent | 8b05b773b6030de5b1bab1cbb0bf1ff8c34cdbe0 (diff) | |
download | lwn-defd94b75409b983f94548ea2f52ff5787ddb848.tar.gz lwn-defd94b75409b983f94548ea2f52ff5787ddb848.zip |
[SCSI] seperate max_sectors from max_hw_sectors
- export __blk_put_request and blk_execute_rq_nowait
needed for async REQ_BLOCK_PC requests
- seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and
SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was
already testing against max_sectors and SCSI-ml was setting max_sectors and
max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only
prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set
a valid max_hw_sectors for all LLDs. Today if a LLD does not set it
SCSI-ml sets it to a safe default and some LLDs set it to a artificial low
value to overcome memory and feedback issues.
Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024,
drivers that used to call blk_queue_max_sectors with a large value of
max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'fs/bio.c')
-rw-r--r-- | fs/bio.c | 20 |
1 files changed, 11 insertions, 9 deletions
@@ -313,7 +313,8 @@ int bio_get_nr_vecs(struct block_device *bdev) } static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page - *page, unsigned int len, unsigned int offset) + *page, unsigned int len, unsigned int offset, + unsigned short max_sectors) { int retried_segments = 0; struct bio_vec *bvec; @@ -327,7 +328,7 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page if (bio->bi_vcnt >= bio->bi_max_vecs) return 0; - if (((bio->bi_size + len) >> 9) > q->max_sectors) + if (((bio->bi_size + len) >> 9) > max_sectors) return 0; /* @@ -401,7 +402,7 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page int bio_add_pc_page(request_queue_t *q, struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { - return __bio_add_page(q, bio, page, len, offset); + return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); } /** @@ -420,8 +421,8 @@ int bio_add_pc_page(request_queue_t *q, struct bio *bio, struct page *page, int bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { - return __bio_add_page(bdev_get_queue(bio->bi_bdev), bio, page, - len, offset); + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + return __bio_add_page(q, bio, page, len, offset, q->max_sectors); } struct bio_map_data { @@ -533,7 +534,7 @@ struct bio *bio_copy_user(request_queue_t *q, unsigned long uaddr, break; } - if (__bio_add_page(q, bio, page, bytes, 0) < bytes) { + if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { ret = -EINVAL; break; } @@ -647,7 +648,8 @@ static struct bio *__bio_map_user_iov(request_queue_t *q, /* * sorry... */ - if (__bio_add_page(q, bio, pages[j], bytes, offset) < bytes) + if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < + bytes) break; len -= bytes; @@ -820,8 +822,8 @@ static struct bio *__bio_map_kern(request_queue_t *q, void *data, if (bytes > len) bytes = len; - if (__bio_add_page(q, bio, virt_to_page(data), bytes, - offset) < bytes) + if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, + offset) < bytes) break; data += bytes; |