[PATCH 6/8] bio: remove size/segments limit on bio_{copy|map}_{user|kern}*()
From: Tejun Heo
Date: Wed Apr 01 2009 - 07:07:34 EST
Impact: API improvement, constant renames
bio_{copy|map}_{user|kern}*() don't guarantee successful allocation
and thus don't have any reason to use bio_alloc(). Switch to
bio_kmalloc(). This removes size/segments limit from these APIs,
which will be used to fix multiple bio mapping bug in
blk_rq_map_user().
As this means that bio size is not capped, rename BIO_MAX_* to
BIO_GUARANTEED_*.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
block/blk-map.c | 12 +++++++-----
drivers/md/dm-io.c | 4 ++--
drivers/md/dm.c | 4 ++--
drivers/scsi/scsi_lib.c | 3 ++-
fs/bio.c | 10 +++++-----
fs/btrfs/extent_io.c | 2 +-
fs/ext4/extents.c | 4 ++--
fs/xfs/linux-2.6/xfs_buf.c | 2 +-
include/linux/bio.h | 6 +++---
9 files changed, 25 insertions(+), 22 deletions(-)
diff --git a/block/blk-map.c b/block/blk-map.c
index f103729..6718021 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -127,17 +127,19 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
while (bytes_read != len) {
unsigned long map_len, end, start;
- map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
+ map_len = min_t(unsigned long, len - bytes_read,
+ BIO_GUARANTEED_SIZE);
end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
>> PAGE_SHIFT;
start = (unsigned long)ubuf >> PAGE_SHIFT;
/*
- * A bad offset could cause us to require BIO_MAX_PAGES + 1
- * pages. If this happens we just lower the requested
- * mapping len by a page so that we can fit
+ * A bad offset could cause us to require
+ * BIO_GUARANTEED_PAGES + 1 pages. If this happens we
+ * just lower the requested mapping len by a page so
+ * that we can fit
*/
- if (end - start > BIO_MAX_PAGES)
+ if (end - start > BIO_GUARANTEED_PAGES)
map_len -= PAGE_SIZE;
ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 36e2b5e..38a175a 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -292,8 +292,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
(PAGE_SIZE >> SECTOR_SHIFT));
num_bvecs = 1 + min_t(int, bio_get_nr_vecs(where->bdev),
num_bvecs);
- if (unlikely(num_bvecs > BIO_MAX_PAGES))
- num_bvecs = BIO_MAX_PAGES;
+ if (unlikely(num_bvecs > BIO_GUARANTEED_PAGES))
+ num_bvecs = BIO_GUARANTEED_PAGES;
bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8d40f27..4949112 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -894,8 +894,8 @@ static int dm_merge_bvec(struct request_queue *q,
/*
* Find maximum amount of I/O that won't need splitting
*/
- max_sectors = min(max_io_len(md, bvm->bi_sector, ti),
- (sector_t) BIO_MAX_SECTORS);
+ max_sectors = min_t(sector_t, max_io_len(md, bvm->bi_sector, ti),
+ BIO_GUARANTEED_SECTORS);
max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
if (max_size < 0)
max_size = 0;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b82ffd9..3196c83 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -351,7 +351,8 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
bytes = min(bytes, data_len);
if (!bio) {
- nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
+ nr_vecs = min_t(int, BIO_GUARANTEED_PAGES,
+ nr_pages);
nr_pages -= nr_vecs;
bio = bio_alloc(gfp, nr_vecs);
diff --git a/fs/bio.c b/fs/bio.c
index e15e457..8ad9784 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -40,7 +40,7 @@ static mempool_t *bio_split_pool __read_mostly;
*/
#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
- BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
+ BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_GUARANTEED_PAGES),
};
#undef BV
@@ -187,7 +187,7 @@ struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
case 65 ... 128:
*idx = 4;
break;
- case 129 ... BIO_MAX_PAGES:
+ case 129 ... BIO_GUARANTEED_PAGES:
*idx = 5;
break;
default:
@@ -818,7 +818,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
return ERR_PTR(-ENOMEM);
ret = -ENOMEM;
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
goto out_bmd;
@@ -942,7 +942,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
if (!nr_pages)
return ERR_PTR(-EINVAL);
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
return ERR_PTR(-ENOMEM);
@@ -1126,7 +1126,7 @@ static struct bio *__bio_map_kern(struct request_queue *q, void *data,
int offset, i;
struct bio *bio;
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
return ERR_PTR(-ENOMEM);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index ebe6b29..8560995 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1899,7 +1899,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
}
}
if (this_compressed)
- nr = BIO_MAX_PAGES;
+ nr = BIO_GUARANTEED_PAGES;
else
nr = bio_get_nr_vecs(bdev);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e0aa4fe..6aad7b2 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2315,8 +2315,8 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
while (ee_len > 0) {
- if (ee_len > BIO_MAX_PAGES)
- len = BIO_MAX_PAGES;
+ if (ee_len > BIO_GUARANTEED_PAGES)
+ len = BIO_GUARANTEED_PAGES;
else
len = ee_len;
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index aa1016b..5d7c571 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1211,7 +1211,7 @@ _xfs_buf_ioapply(
next_chunk:
atomic_inc(&bp->b_io_remaining);
- nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT);
+ nr_pages = BIO_GUARANTEED_SECTORS >> (PAGE_SHIFT - BBSHIFT);
if (nr_pages > total_nr_pages)
nr_pages = total_nr_pages;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index e01e41d..8647dd9 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -36,9 +36,9 @@
#define BIO_BUG_ON
#endif
-#define BIO_MAX_PAGES 256
-#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
-#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
+#define BIO_GUARANTEED_PAGES 256
+#define BIO_GUARANTEED_SIZE (BIO_GUARANTEED_PAGES << PAGE_CACHE_SHIFT)
+#define BIO_GUARANTEED_SECTORS (BIO_GUARANTEED_SIZE >> 9)
#define BIO_INLINE_VECS 4
--
1.6.0.2
--
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