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-rw-r--r--block/bio.c212
1 files changed, 78 insertions, 134 deletions
diff --git a/block/bio.c b/block/bio.c
index d6e5ba3399f0..515b5434fe2d 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -269,7 +269,6 @@ static void bio_free(struct bio *bio)
void bio_init(struct bio *bio)
{
memset(bio, 0, sizeof(*bio));
- bio->bi_flags = 1 << BIO_UPTODATE;
atomic_set(&bio->__bi_remaining, 1);
atomic_set(&bio->__bi_cnt, 1);
}
@@ -292,14 +291,17 @@ void bio_reset(struct bio *bio)
__bio_free(bio);
memset(bio, 0, BIO_RESET_BYTES);
- bio->bi_flags = flags | (1 << BIO_UPTODATE);
+ bio->bi_flags = flags;
atomic_set(&bio->__bi_remaining, 1);
}
EXPORT_SYMBOL(bio_reset);
-static void bio_chain_endio(struct bio *bio, int error)
+static void bio_chain_endio(struct bio *bio)
{
- bio_endio(bio->bi_private, error);
+ struct bio *parent = bio->bi_private;
+
+ parent->bi_error = bio->bi_error;
+ bio_endio(parent);
bio_put(bio);
}
@@ -309,7 +311,7 @@ static void bio_chain_endio(struct bio *bio, int error)
*/
static inline void bio_inc_remaining(struct bio *bio)
{
- bio->bi_flags |= (1 << BIO_CHAIN);
+ bio_set_flag(bio, BIO_CHAIN);
smp_mb__before_atomic();
atomic_inc(&bio->__bi_remaining);
}
@@ -493,7 +495,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
if (unlikely(!bvl))
goto err_free;
- bio->bi_flags |= 1 << BIO_OWNS_VEC;
+ bio_set_flag(bio, BIO_OWNS_VEC);
} else if (nr_iovecs) {
bvl = bio->bi_inline_vecs;
}
@@ -578,7 +580,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
* so we don't set nor calculate new physical/hw segment counts here
*/
bio->bi_bdev = bio_src->bi_bdev;
- bio->bi_flags |= 1 << BIO_CLONED;
+ bio_set_flag(bio, BIO_CLONED);
bio->bi_rw = bio_src->bi_rw;
bio->bi_iter = bio_src->bi_iter;
bio->bi_io_vec = bio_src->bi_io_vec;
@@ -692,31 +694,22 @@ integrity_clone:
EXPORT_SYMBOL(bio_clone_bioset);
/**
- * bio_get_nr_vecs - return approx number of vecs
- * @bdev: I/O target
+ * bio_add_pc_page - attempt to add page to bio
+ * @q: the target queue
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
*
- * Return the approximate number of pages we can send to this target.
- * There's no guarantee that you will be able to fit this number of pages
- * into a bio, it does not account for dynamic restrictions that vary
- * on offset.
+ * Attempt to add a page to the bio_vec maplist. This can fail for a
+ * number of reasons, such as the bio being full or target block device
+ * limitations. The target block device must allow bio's up to PAGE_SIZE,
+ * so it is always possible to add a single page to an empty bio.
+ *
+ * This should only be used by REQ_PC bios.
*/
-int bio_get_nr_vecs(struct block_device *bdev)
-{
- struct request_queue *q = bdev_get_queue(bdev);
- int nr_pages;
-
- nr_pages = min_t(unsigned,
- queue_max_segments(q),
- queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1);
-
- return min_t(unsigned, nr_pages, BIO_MAX_PAGES);
-
-}
-EXPORT_SYMBOL(bio_get_nr_vecs);
-
-static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
- *page, unsigned int len, unsigned int offset,
- unsigned int max_sectors)
+int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
+ *page, unsigned int len, unsigned int offset)
{
int retried_segments = 0;
struct bio_vec *bvec;
@@ -727,7 +720,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
if (unlikely(bio_flagged(bio, BIO_CLONED)))
return 0;
- if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
+ if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q))
return 0;
/*
@@ -740,28 +733,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
if (page == prev->bv_page &&
offset == prev->bv_offset + prev->bv_len) {
- unsigned int prev_bv_len = prev->bv_len;
prev->bv_len += len;
-
- if (q->merge_bvec_fn) {
- struct bvec_merge_data bvm = {
- /* prev_bvec is already charged in
- bi_size, discharge it in order to
- simulate merging updated prev_bvec
- as new bvec. */
- .bi_bdev = bio->bi_bdev,
- .bi_sector = bio->bi_iter.bi_sector,
- .bi_size = bio->bi_iter.bi_size -
- prev_bv_len,
- .bi_rw = bio->bi_rw,
- };
-
- if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) {
- prev->bv_len -= len;
- return 0;
- }
- }
-
bio->bi_iter.bi_size += len;
goto done;
}
@@ -770,8 +742,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
* If the queue doesn't support SG gaps and adding this
* offset would create a gap, disallow it.
*/
- if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) &&
- bvec_gap_to_prev(prev, offset))
+ if (bvec_gap_to_prev(q, prev, offset))
return 0;
}
@@ -804,30 +775,9 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
blk_recount_segments(q, bio);
}
- /*
- * if queue has other restrictions (eg varying max sector size
- * depending on offset), it can specify a merge_bvec_fn in the
- * queue to get further control
- */
- if (q->merge_bvec_fn) {
- struct bvec_merge_data bvm = {
- .bi_bdev = bio->bi_bdev,
- .bi_sector = bio->bi_iter.bi_sector,
- .bi_size = bio->bi_iter.bi_size - len,
- .bi_rw = bio->bi_rw,
- };
-
- /*
- * merge_bvec_fn() returns number of bytes it can accept
- * at this offset
- */
- if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len)
- goto failed;
- }
-
/* If we may be able to merge these biovecs, force a recount */
if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
- bio->bi_flags &= ~(1 << BIO_SEG_VALID);
+ bio_clear_flag(bio, BIO_SEG_VALID);
done:
return len;
@@ -841,28 +791,6 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
blk_recount_segments(q, bio);
return 0;
}
-
-/**
- * bio_add_pc_page - attempt to add page to bio
- * @q: the target queue
- * @bio: destination bio
- * @page: page to add
- * @len: vec entry length
- * @offset: vec entry offset
- *
- * Attempt to add a page to the bio_vec maplist. This can fail for a
- * number of reasons, such as the bio being full or target block device
- * limitations. The target block device must allow bio's up to PAGE_SIZE,
- * so it is always possible to add a single page to an empty bio.
- *
- * This should only be used by REQ_PC bios.
- */
-int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page,
- unsigned int len, unsigned int offset)
-{
- return __bio_add_page(q, bio, page, len, offset,
- queue_max_hw_sectors(q));
-}
EXPORT_SYMBOL(bio_add_pc_page);
/**
@@ -872,22 +800,47 @@ EXPORT_SYMBOL(bio_add_pc_page);
* @len: vec entry length
* @offset: vec entry offset
*
- * Attempt to add a page to the bio_vec maplist. This can fail for a
- * number of reasons, such as the bio being full or target block device
- * limitations. The target block device must allow bio's up to PAGE_SIZE,
- * so it is always possible to add a single page to an empty bio.
+ * Attempt to add a page to the bio_vec maplist. This will only fail
+ * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
*/
-int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
- unsigned int offset)
+int bio_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
{
- struct request_queue *q = bdev_get_queue(bio->bi_bdev);
- unsigned int max_sectors;
+ struct bio_vec *bv;
+
+ /*
+ * cloned bio must not modify vec list
+ */
+ if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
+ return 0;
- max_sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector);
- if ((max_sectors < (len >> 9)) && !bio->bi_iter.bi_size)
- max_sectors = len >> 9;
+ /*
+ * For filesystems with a blocksize smaller than the pagesize
+ * we will often be called with the same page as last time and
+ * a consecutive offset. Optimize this special case.
+ */
+ if (bio->bi_vcnt > 0) {
+ bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
- return __bio_add_page(q, bio, page, len, offset, max_sectors);
+ if (page == bv->bv_page &&
+ offset == bv->bv_offset + bv->bv_len) {
+ bv->bv_len += len;
+ goto done;
+ }
+ }
+
+ if (bio->bi_vcnt >= bio->bi_max_vecs)
+ return 0;
+
+ bv = &bio->bi_io_vec[bio->bi_vcnt];
+ bv->bv_page = page;
+ bv->bv_len = len;
+ bv->bv_offset = offset;
+
+ bio->bi_vcnt++;
+done:
+ bio->bi_iter.bi_size += len;
+ return len;
}
EXPORT_SYMBOL(bio_add_page);
@@ -896,11 +849,11 @@ struct submit_bio_ret {
int error;
};
-static void submit_bio_wait_endio(struct bio *bio, int error)
+static void submit_bio_wait_endio(struct bio *bio)
{
struct submit_bio_ret *ret = bio->bi_private;
- ret->error = error;
+ ret->error = bio->bi_error;
complete(&ret->event);
}
@@ -1388,7 +1341,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
if (iter->type & WRITE)
bio->bi_rw |= REQ_WRITE;
- bio->bi_flags |= (1 << BIO_USER_MAPPED);
+ bio_set_flag(bio, BIO_USER_MAPPED);
/*
* subtle -- if __bio_map_user() ended up bouncing a bio,
@@ -1445,7 +1398,7 @@ void bio_unmap_user(struct bio *bio)
}
EXPORT_SYMBOL(bio_unmap_user);
-static void bio_map_kern_endio(struct bio *bio, int err)
+static void bio_map_kern_endio(struct bio *bio)
{
bio_put(bio);
}
@@ -1501,13 +1454,13 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
}
EXPORT_SYMBOL(bio_map_kern);
-static void bio_copy_kern_endio(struct bio *bio, int err)
+static void bio_copy_kern_endio(struct bio *bio)
{
bio_free_pages(bio);
bio_put(bio);
}
-static void bio_copy_kern_endio_read(struct bio *bio, int err)
+static void bio_copy_kern_endio_read(struct bio *bio)
{
char *p = bio->bi_private;
struct bio_vec *bvec;
@@ -1518,7 +1471,7 @@ static void bio_copy_kern_endio_read(struct bio *bio, int err)
p += bvec->bv_len;
}
- bio_copy_kern_endio(bio, err);
+ bio_copy_kern_endio(bio);
}
/**
@@ -1768,7 +1721,7 @@ static inline bool bio_remaining_done(struct bio *bio)
BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
if (atomic_dec_and_test(&bio->__bi_remaining)) {
- clear_bit(BIO_CHAIN, &bio->bi_flags);
+ bio_clear_flag(bio, BIO_CHAIN);
return true;
}
@@ -1778,25 +1731,15 @@ static inline bool bio_remaining_done(struct bio *bio)
/**
* bio_endio - end I/O on a bio
* @bio: bio
- * @error: error, if any
*
* Description:
- * bio_endio() will end I/O on the whole bio. bio_endio() is the
- * preferred way to end I/O on a bio, it takes care of clearing
- * BIO_UPTODATE on error. @error is 0 on success, and and one of the
- * established -Exxxx (-EIO, for instance) error values in case
- * something went wrong. No one should call bi_end_io() directly on a
- * bio unless they own it and thus know that it has an end_io
- * function.
+ * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred
+ * way to end I/O on a bio. No one should call bi_end_io() directly on a
+ * bio unless they own it and thus know that it has an end_io function.
**/
-void bio_endio(struct bio *bio, int error)
+void bio_endio(struct bio *bio)
{
while (bio) {
- if (error)
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
- error = -EIO;
-
if (unlikely(!bio_remaining_done(bio)))
break;
@@ -1810,11 +1753,12 @@ void bio_endio(struct bio *bio, int error)
*/
if (bio->bi_end_io == bio_chain_endio) {
struct bio *parent = bio->bi_private;
+ parent->bi_error = bio->bi_error;
bio_put(bio);
bio = parent;
} else {
if (bio->bi_end_io)
- bio->bi_end_io(bio, error);
+ bio->bi_end_io(bio);
bio = NULL;
}
}
@@ -1882,7 +1826,7 @@ void bio_trim(struct bio *bio, int offset, int size)
if (offset == 0 && size == bio->bi_iter.bi_size)
return;
- clear_bit(BIO_SEG_VALID, &bio->bi_flags);
+ bio_clear_flag(bio, BIO_SEG_VALID);
bio_advance(bio, offset << 9);