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Diffstat (limited to 'fs/bio.c')
-rw-r--r--fs/bio.c297
1 files changed, 179 insertions, 118 deletions
diff --git a/fs/bio.c b/fs/bio.c
index 3cba7ae34d75..77a55bcceedb 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -30,7 +30,7 @@
static struct kmem_cache *bio_slab __read_mostly;
-mempool_t *bio_split_pool __read_mostly;
+static mempool_t *bio_split_pool __read_mostly;
/*
* if you change this list, also change bvec_alloc or things will
@@ -60,25 +60,46 @@ struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct
struct bio_vec *bvl;
/*
- * see comment near bvec_array define!
+ * If 'bs' is given, lookup the pool and do the mempool alloc.
+ * If not, this is a bio_kmalloc() allocation and just do a
+ * kzalloc() for the exact number of vecs right away.
*/
- switch (nr) {
- case 1 : *idx = 0; break;
- case 2 ... 4: *idx = 1; break;
- case 5 ... 16: *idx = 2; break;
- case 17 ... 64: *idx = 3; break;
- case 65 ... 128: *idx = 4; break;
- case 129 ... BIO_MAX_PAGES: *idx = 5; break;
+ if (bs) {
+ /*
+ * see comment near bvec_array define!
+ */
+ switch (nr) {
+ case 1:
+ *idx = 0;
+ break;
+ case 2 ... 4:
+ *idx = 1;
+ break;
+ case 5 ... 16:
+ *idx = 2;
+ break;
+ case 17 ... 64:
+ *idx = 3;
+ break;
+ case 65 ... 128:
+ *idx = 4;
+ break;
+ case 129 ... BIO_MAX_PAGES:
+ *idx = 5;
+ break;
default:
return NULL;
- }
- /*
- * idx now points to the pool we want to allocate from
- */
+ }
- bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask);
- if (bvl)
- memset(bvl, 0, bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
+ /*
+ * idx now points to the pool we want to allocate from
+ */
+ bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask);
+ if (bvl)
+ memset(bvl, 0,
+ bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
+ } else
+ bvl = kzalloc(nr * sizeof(struct bio_vec), gfp_mask);
return bvl;
}
@@ -107,10 +128,17 @@ static void bio_fs_destructor(struct bio *bio)
bio_free(bio, fs_bio_set);
}
+static void bio_kmalloc_destructor(struct bio *bio)
+{
+ kfree(bio->bi_io_vec);
+ kfree(bio);
+}
+
void bio_init(struct bio *bio)
{
memset(bio, 0, sizeof(*bio));
bio->bi_flags = 1 << BIO_UPTODATE;
+ bio->bi_comp_cpu = -1;
atomic_set(&bio->bi_cnt, 1);
}
@@ -118,19 +146,25 @@ void bio_init(struct bio *bio)
* bio_alloc_bioset - allocate a bio for I/O
* @gfp_mask: the GFP_ mask given to the slab allocator
* @nr_iovecs: number of iovecs to pre-allocate
- * @bs: the bio_set to allocate from
+ * @bs: the bio_set to allocate from. If %NULL, just use kmalloc
*
* Description:
- * bio_alloc_bioset will first try it's on mempool to satisfy the allocation.
+ * bio_alloc_bioset will first try its own mempool to satisfy the allocation.
* If %__GFP_WAIT is set then we will block on the internal pool waiting
- * for a &struct bio to become free.
+ * for a &struct bio to become free. If a %NULL @bs is passed in, we will
+ * fall back to just using @kmalloc to allocate the required memory.
*
* allocate bio and iovecs from the memory pools specified by the
- * bio_set structure.
+ * bio_set structure, or @kmalloc if none given.
**/
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
- struct bio *bio = mempool_alloc(bs->bio_pool, gfp_mask);
+ struct bio *bio;
+
+ if (bs)
+ bio = mempool_alloc(bs->bio_pool, gfp_mask);
+ else
+ bio = kmalloc(sizeof(*bio), gfp_mask);
if (likely(bio)) {
struct bio_vec *bvl = NULL;
@@ -141,7 +175,10 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
if (unlikely(!bvl)) {
- mempool_free(bio, bs->bio_pool);
+ if (bs)
+ mempool_free(bio, bs->bio_pool);
+ else
+ kfree(bio);
bio = NULL;
goto out;
}
@@ -164,6 +201,23 @@ struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
return bio;
}
+/*
+ * Like bio_alloc(), but doesn't use a mempool backing. This means that
+ * it CAN fail, but while bio_alloc() can only be used for allocations
+ * that have a short (finite) life span, bio_kmalloc() should be used
+ * for more permanent bio allocations (like allocating some bio's for
+ * initalization or setup purposes).
+ */
+struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
+{
+ struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+
+ if (bio)
+ bio->bi_destructor = bio_kmalloc_destructor;
+
+ return bio;
+}
+
void zero_fill_bio(struct bio *bio)
{
unsigned long flags;
@@ -208,14 +262,6 @@ inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
return bio->bi_phys_segments;
}
-inline int bio_hw_segments(struct request_queue *q, struct bio *bio)
-{
- if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
- blk_recount_segments(q, bio);
-
- return bio->bi_hw_segments;
-}
-
/**
* __bio_clone - clone a bio
* @bio: destination bio
@@ -350,8 +396,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
*/
while (bio->bi_phys_segments >= q->max_phys_segments
- || bio->bi_hw_segments >= q->max_hw_segments
- || BIOVEC_VIRT_OVERSIZE(bio->bi_size)) {
+ || bio->bi_phys_segments >= q->max_hw_segments) {
if (retried_segments)
return 0;
@@ -395,13 +440,11 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
}
/* If we may be able to merge these biovecs, force a recount */
- if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec) ||
- BIOVEC_VIRT_MERGEABLE(bvec-1, bvec)))
+ if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
bio->bi_flags &= ~(1 << BIO_SEG_VALID);
bio->bi_vcnt++;
bio->bi_phys_segments++;
- bio->bi_hw_segments++;
done:
bio->bi_size += len;
return len;
@@ -449,16 +492,19 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
struct bio_map_data {
struct bio_vec *iovecs;
- int nr_sgvecs;
struct sg_iovec *sgvecs;
+ int nr_sgvecs;
+ int is_our_pages;
};
static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
- struct sg_iovec *iov, int iov_count)
+ struct sg_iovec *iov, int iov_count,
+ int is_our_pages)
{
memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
bmd->nr_sgvecs = iov_count;
+ bmd->is_our_pages = is_our_pages;
bio->bi_private = bmd;
}
@@ -493,7 +539,8 @@ static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
}
static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
- struct sg_iovec *iov, int iov_count, int uncopy)
+ struct sg_iovec *iov, int iov_count, int uncopy,
+ int do_free_page)
{
int ret = 0, i;
struct bio_vec *bvec;
@@ -536,7 +583,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
}
}
- if (uncopy)
+ if (do_free_page)
__free_page(bvec->bv_page);
}
@@ -553,10 +600,11 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
int bio_uncopy_user(struct bio *bio)
{
struct bio_map_data *bmd = bio->bi_private;
- int ret;
-
- ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, bmd->nr_sgvecs, 1);
+ int ret = 0;
+ if (!bio_flagged(bio, BIO_NULL_MAPPED))
+ ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
+ bmd->nr_sgvecs, 1, bmd->is_our_pages);
bio_free_map_data(bmd);
bio_put(bio);
return ret;
@@ -565,16 +613,20 @@ int bio_uncopy_user(struct bio *bio)
/**
* bio_copy_user_iov - copy user data to bio
* @q: destination block queue
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
* @iov: the iovec.
* @iov_count: number of elements in the iovec
* @write_to_vm: bool indicating writing to pages or not
+ * @gfp_mask: memory allocation flags
*
* Prepares and returns a bio for indirect user io, bouncing data
* to/from kernel pages as necessary. Must be paired with
* call bio_uncopy_user() on io completion.
*/
-struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
- int iov_count, int write_to_vm)
+struct bio *bio_copy_user_iov(struct request_queue *q,
+ struct rq_map_data *map_data,
+ struct sg_iovec *iov, int iov_count,
+ int write_to_vm, gfp_t gfp_mask)
{
struct bio_map_data *bmd;
struct bio_vec *bvec;
@@ -597,25 +649,38 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
len += iov[i].iov_len;
}
- bmd = bio_alloc_map_data(nr_pages, iov_count, GFP_KERNEL);
+ bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
if (!bmd)
return ERR_PTR(-ENOMEM);
ret = -ENOMEM;
- bio = bio_alloc(GFP_KERNEL, nr_pages);
+ bio = bio_alloc(gfp_mask, nr_pages);
if (!bio)
goto out_bmd;
bio->bi_rw |= (!write_to_vm << BIO_RW);
ret = 0;
+ i = 0;
while (len) {
- unsigned int bytes = PAGE_SIZE;
+ unsigned int bytes;
+
+ if (map_data)
+ bytes = 1U << (PAGE_SHIFT + map_data->page_order);
+ else
+ bytes = PAGE_SIZE;
if (bytes > len)
bytes = len;
- page = alloc_page(q->bounce_gfp | GFP_KERNEL);
+ if (map_data) {
+ if (i == map_data->nr_entries) {
+ ret = -ENOMEM;
+ break;
+ }
+ page = map_data->pages[i++];
+ } else
+ page = alloc_page(q->bounce_gfp | gfp_mask);
if (!page) {
ret = -ENOMEM;
break;
@@ -634,16 +699,17 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
* success
*/
if (!write_to_vm) {
- ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0);
+ ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
if (ret)
goto cleanup;
}
- bio_set_map_data(bmd, bio, iov, iov_count);
+ bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
return bio;
cleanup:
- bio_for_each_segment(bvec, bio, i)
- __free_page(bvec->bv_page);
+ if (!map_data)
+ bio_for_each_segment(bvec, bio, i)
+ __free_page(bvec->bv_page);
bio_put(bio);
out_bmd:
@@ -654,29 +720,32 @@ out_bmd:
/**
* bio_copy_user - copy user data to bio
* @q: destination block queue
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
* @uaddr: start of user address
* @len: length in bytes
* @write_to_vm: bool indicating writing to pages or not
+ * @gfp_mask: memory allocation flags
*
* Prepares and returns a bio for indirect user io, bouncing data
* to/from kernel pages as necessary. Must be paired with
* call bio_uncopy_user() on io completion.
*/
-struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr,
- unsigned int len, int write_to_vm)
+struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
+ unsigned long uaddr, unsigned int len,
+ int write_to_vm, gfp_t gfp_mask)
{
struct sg_iovec iov;
iov.iov_base = (void __user *)uaddr;
iov.iov_len = len;
- return bio_copy_user_iov(q, &iov, 1, write_to_vm);
+ return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
}
static struct bio *__bio_map_user_iov(struct request_queue *q,
struct block_device *bdev,
struct sg_iovec *iov, int iov_count,
- int write_to_vm)
+ int write_to_vm, gfp_t gfp_mask)
{
int i, j;
int nr_pages = 0;
@@ -702,12 +771,12 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
if (!nr_pages)
return ERR_PTR(-EINVAL);
- bio = bio_alloc(GFP_KERNEL, nr_pages);
+ bio = bio_alloc(gfp_mask, nr_pages);
if (!bio)
return ERR_PTR(-ENOMEM);
ret = -ENOMEM;
- pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
if (!pages)
goto out;
@@ -786,19 +855,21 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
* @uaddr: start of user address
* @len: length in bytes
* @write_to_vm: bool indicating writing to pages or not
+ * @gfp_mask: memory allocation flags
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len, int write_to_vm)
+ unsigned long uaddr, unsigned int len, int write_to_vm,
+ gfp_t gfp_mask)
{
struct sg_iovec iov;
iov.iov_base = (void __user *)uaddr;
iov.iov_len = len;
- return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm);
+ return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
}
/**
@@ -808,18 +879,19 @@ struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
* @iov: the iovec.
* @iov_count: number of elements in the iovec
* @write_to_vm: bool indicating writing to pages or not
+ * @gfp_mask: memory allocation flags
*
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
struct sg_iovec *iov, int iov_count,
- int write_to_vm)
+ int write_to_vm, gfp_t gfp_mask)
{
struct bio *bio;
- bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm);
-
+ bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
+ gfp_mask);
if (IS_ERR(bio))
return bio;
@@ -976,48 +1048,13 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
gfp_t gfp_mask, int reading)
{
- unsigned long kaddr = (unsigned long)data;
- unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned long start = kaddr >> PAGE_SHIFT;
- const int nr_pages = end - start;
struct bio *bio;
struct bio_vec *bvec;
- struct bio_map_data *bmd;
- int i, ret;
- struct sg_iovec iov;
-
- iov.iov_base = data;
- iov.iov_len = len;
-
- bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
- if (!bmd)
- return ERR_PTR(-ENOMEM);
-
- ret = -ENOMEM;
- bio = bio_alloc(gfp_mask, nr_pages);
- if (!bio)
- goto out_bmd;
-
- while (len) {
- struct page *page;
- unsigned int bytes = PAGE_SIZE;
-
- if (bytes > len)
- bytes = len;
-
- page = alloc_page(q->bounce_gfp | gfp_mask);
- if (!page) {
- ret = -ENOMEM;
- goto cleanup;
- }
-
- if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
- ret = -EINVAL;
- goto cleanup;
- }
+ int i;
- len -= bytes;
- }
+ bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
+ if (IS_ERR(bio))
+ return bio;
if (!reading) {
void *p = data;
@@ -1030,20 +1067,9 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
}
}
- bio->bi_private = bmd;
bio->bi_end_io = bio_copy_kern_endio;
- bio_set_map_data(bmd, bio, &iov, 1);
return bio;
-cleanup:
- bio_for_each_segment(bvec, bio, i)
- __free_page(bvec->bv_page);
-
- bio_put(bio);
-out_bmd:
- bio_free_map_data(bmd);
-
- return ERR_PTR(ret);
}
/*
@@ -1230,9 +1256,9 @@ static void bio_pair_end_2(struct bio *bi, int err)
* split a bio - only worry about a bio with a single page
* in it's iovec
*/
-struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
+struct bio_pair *bio_split(struct bio *bi, int first_sectors)
{
- struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO);
+ struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
if (!bp)
return bp;
@@ -1266,7 +1292,7 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
bp->bio2.bi_end_io = bio_pair_end_2;
bp->bio1.bi_private = bi;
- bp->bio2.bi_private = pool;
+ bp->bio2.bi_private = bio_split_pool;
if (bio_integrity(bi))
bio_integrity_split(bi, bp, first_sectors);
@@ -1274,6 +1300,42 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
return bp;
}
+/**
+ * bio_sector_offset - Find hardware sector offset in bio
+ * @bio: bio to inspect
+ * @index: bio_vec index
+ * @offset: offset in bv_page
+ *
+ * Return the number of hardware sectors between beginning of bio
+ * and an end point indicated by a bio_vec index and an offset
+ * within that vector's page.
+ */
+sector_t bio_sector_offset(struct bio *bio, unsigned short index,
+ unsigned int offset)
+{
+ unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue);
+ struct bio_vec *bv;
+ sector_t sectors;
+ int i;
+
+ sectors = 0;
+
+ if (index >= bio->bi_idx)
+ index = bio->bi_vcnt - 1;
+
+ __bio_for_each_segment(bv, bio, i, 0) {
+ if (i == index) {
+ if (offset > bv->bv_offset)
+ sectors += (offset - bv->bv_offset) / sector_sz;
+ break;
+ }
+
+ sectors += bv->bv_len / sector_sz;
+ }
+
+ return sectors;
+}
+EXPORT_SYMBOL(bio_sector_offset);
/*
* create memory pools for biovec's in a bio_set.
@@ -1376,6 +1438,7 @@ static int __init init_bio(void)
subsys_initcall(init_bio);
EXPORT_SYMBOL(bio_alloc);
+EXPORT_SYMBOL(bio_kmalloc);
EXPORT_SYMBOL(bio_put);
EXPORT_SYMBOL(bio_free);
EXPORT_SYMBOL(bio_endio);
@@ -1383,7 +1446,6 @@ EXPORT_SYMBOL(bio_init);
EXPORT_SYMBOL(__bio_clone);
EXPORT_SYMBOL(bio_clone);
EXPORT_SYMBOL(bio_phys_segments);
-EXPORT_SYMBOL(bio_hw_segments);
EXPORT_SYMBOL(bio_add_page);
EXPORT_SYMBOL(bio_add_pc_page);
EXPORT_SYMBOL(bio_get_nr_vecs);
@@ -1393,7 +1455,6 @@ EXPORT_SYMBOL(bio_map_kern);
EXPORT_SYMBOL(bio_copy_kern);
EXPORT_SYMBOL(bio_pair_release);
EXPORT_SYMBOL(bio_split);
-EXPORT_SYMBOL(bio_split_pool);
EXPORT_SYMBOL(bio_copy_user);
EXPORT_SYMBOL(bio_uncopy_user);
EXPORT_SYMBOL(bioset_create);