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-rw-r--r--fs/bio.c231
1 files changed, 105 insertions, 126 deletions
diff --git a/fs/bio.c b/fs/bio.c
index 71072ab99128..9298c65ad9c7 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -55,6 +55,7 @@ static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
* IO code that does not need private memory pools.
*/
struct bio_set *fs_bio_set;
+EXPORT_SYMBOL(fs_bio_set);
/*
* Our slab pool management
@@ -233,26 +234,37 @@ fallback:
return bvl;
}
-void bio_free(struct bio *bio, struct bio_set *bs)
+static void __bio_free(struct bio *bio)
{
+ bio_disassociate_task(bio);
+
+ if (bio_integrity(bio))
+ bio_integrity_free(bio);
+}
+
+static void bio_free(struct bio *bio)
+{
+ struct bio_set *bs = bio->bi_pool;
void *p;
- if (bio_has_allocated_vec(bio))
- bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
+ __bio_free(bio);
- if (bio_integrity(bio))
- bio_integrity_free(bio, bs);
+ if (bs) {
+ if (bio_has_allocated_vec(bio))
+ bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
- /*
- * If we have front padding, adjust the bio pointer before freeing
- */
- p = bio;
- if (bs->front_pad)
+ /*
+ * If we have front padding, adjust the bio pointer before freeing
+ */
+ p = bio;
p -= bs->front_pad;
- mempool_free(p, bs->bio_pool);
+ mempool_free(p, bs->bio_pool);
+ } else {
+ /* Bio was allocated by bio_kmalloc() */
+ kfree(bio);
+ }
}
-EXPORT_SYMBOL(bio_free);
void bio_init(struct bio *bio)
{
@@ -263,48 +275,85 @@ void bio_init(struct bio *bio)
EXPORT_SYMBOL(bio_init);
/**
+ * bio_reset - reinitialize a bio
+ * @bio: bio to reset
+ *
+ * Description:
+ * After calling bio_reset(), @bio will be in the same state as a freshly
+ * allocated bio returned bio bio_alloc_bioset() - the only fields that are
+ * preserved are the ones that are initialized by bio_alloc_bioset(). See
+ * comment in struct bio.
+ */
+void bio_reset(struct bio *bio)
+{
+ unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS);
+
+ __bio_free(bio);
+
+ memset(bio, 0, BIO_RESET_BYTES);
+ bio->bi_flags = flags|(1 << BIO_UPTODATE);
+}
+EXPORT_SYMBOL(bio_reset);
+
+/**
* 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.
*
* Description:
- * bio_alloc_bioset will 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.
+ * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
+ * backed by the @bs's mempool.
*
- * Note that the caller must set ->bi_destructor on successful return
- * of a bio, to do the appropriate freeing of the bio once the reference
- * count drops to zero.
- **/
+ * When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be
+ * able to allocate a bio. This is due to the mempool guarantees. To make this
+ * work, callers must never allocate more than 1 bio at a time from this pool.
+ * Callers that need to allocate more than 1 bio must always submit the
+ * previously allocated bio for IO before attempting to allocate a new one.
+ * Failure to do so can cause deadlocks under memory pressure.
+ *
+ * RETURNS:
+ * Pointer to new bio on success, NULL on failure.
+ */
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
+ unsigned front_pad;
+ unsigned inline_vecs;
unsigned long idx = BIO_POOL_NONE;
struct bio_vec *bvl = NULL;
struct bio *bio;
void *p;
- p = mempool_alloc(bs->bio_pool, gfp_mask);
+ if (!bs) {
+ if (nr_iovecs > UIO_MAXIOV)
+ return NULL;
+
+ p = kmalloc(sizeof(struct bio) +
+ nr_iovecs * sizeof(struct bio_vec),
+ gfp_mask);
+ front_pad = 0;
+ inline_vecs = nr_iovecs;
+ } else {
+ p = mempool_alloc(bs->bio_pool, gfp_mask);
+ front_pad = bs->front_pad;
+ inline_vecs = BIO_INLINE_VECS;
+ }
+
if (unlikely(!p))
return NULL;
- bio = p + bs->front_pad;
+ bio = p + front_pad;
bio_init(bio);
- if (unlikely(!nr_iovecs))
- goto out_set;
-
- if (nr_iovecs <= BIO_INLINE_VECS) {
- bvl = bio->bi_inline_vecs;
- nr_iovecs = BIO_INLINE_VECS;
- } else {
+ if (nr_iovecs > inline_vecs) {
bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
if (unlikely(!bvl))
goto err_free;
-
- nr_iovecs = bvec_nr_vecs(idx);
+ } else if (nr_iovecs) {
+ bvl = bio->bi_inline_vecs;
}
-out_set:
+
+ bio->bi_pool = bs;
bio->bi_flags |= idx << BIO_POOL_OFFSET;
bio->bi_max_vecs = nr_iovecs;
bio->bi_io_vec = bvl;
@@ -316,80 +365,6 @@ err_free:
}
EXPORT_SYMBOL(bio_alloc_bioset);
-static void bio_fs_destructor(struct bio *bio)
-{
- bio_free(bio, fs_bio_set);
-}
-
-/**
- * bio_alloc - allocate a new bio, memory pool backed
- * @gfp_mask: allocation mask to use
- * @nr_iovecs: number of iovecs
- *
- * bio_alloc will allocate a bio and associated bio_vec array that can hold
- * at least @nr_iovecs entries. Allocations will be done from the
- * fs_bio_set. Also see @bio_alloc_bioset and @bio_kmalloc.
- *
- * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
- * a bio. This is due to the mempool guarantees. To make this work, callers
- * must never allocate more than 1 bio at a time from this pool. Callers
- * that need to allocate more than 1 bio must always submit the previously
- * allocated bio for IO before attempting to allocate a new one. Failure to
- * do so can cause livelocks under memory pressure.
- *
- * RETURNS:
- * Pointer to new bio on success, NULL on failure.
- */
-struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
-{
- struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
-
- if (bio)
- bio->bi_destructor = bio_fs_destructor;
-
- return bio;
-}
-EXPORT_SYMBOL(bio_alloc);
-
-static void bio_kmalloc_destructor(struct bio *bio)
-{
- if (bio_integrity(bio))
- bio_integrity_free(bio, fs_bio_set);
- kfree(bio);
-}
-
-/**
- * bio_kmalloc - allocate a bio for I/O using kmalloc()
- * @gfp_mask: the GFP_ mask given to the slab allocator
- * @nr_iovecs: number of iovecs to pre-allocate
- *
- * Description:
- * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask contains
- * %__GFP_WAIT, the allocation is guaranteed to succeed.
- *
- **/
-struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
-{
- struct bio *bio;
-
- if (nr_iovecs > UIO_MAXIOV)
- return NULL;
-
- bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
- gfp_mask);
- if (unlikely(!bio))
- return NULL;
-
- bio_init(bio);
- bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
- bio->bi_max_vecs = nr_iovecs;
- bio->bi_io_vec = bio->bi_inline_vecs;
- bio->bi_destructor = bio_kmalloc_destructor;
-
- return bio;
-}
-EXPORT_SYMBOL(bio_kmalloc);
-
void zero_fill_bio(struct bio *bio)
{
unsigned long flags;
@@ -420,11 +395,8 @@ void bio_put(struct bio *bio)
/*
* last put frees it
*/
- if (atomic_dec_and_test(&bio->bi_cnt)) {
- bio_disassociate_task(bio);
- bio->bi_next = NULL;
- bio->bi_destructor(bio);
- }
+ if (atomic_dec_and_test(&bio->bi_cnt))
+ bio_free(bio);
}
EXPORT_SYMBOL(bio_put);
@@ -466,26 +438,28 @@ void __bio_clone(struct bio *bio, struct bio *bio_src)
EXPORT_SYMBOL(__bio_clone);
/**
- * bio_clone - clone a bio
+ * bio_clone_bioset - clone a bio
* @bio: bio to clone
* @gfp_mask: allocation priority
+ * @bs: bio_set to allocate from
*
* Like __bio_clone, only also allocates the returned bio
*/
-struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
+struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask,
+ struct bio_set *bs)
{
- struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
+ struct bio *b;
+ b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bs);
if (!b)
return NULL;
- b->bi_destructor = bio_fs_destructor;
__bio_clone(b, bio);
if (bio_integrity(bio)) {
int ret;
- ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set);
+ ret = bio_integrity_clone(b, bio, gfp_mask);
if (ret < 0) {
bio_put(b);
@@ -495,7 +469,7 @@ struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
return b;
}
-EXPORT_SYMBOL(bio_clone);
+EXPORT_SYMBOL(bio_clone_bioset);
/**
* bio_get_nr_vecs - return approx number of vecs
@@ -1501,7 +1475,7 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
bi->bi_sector + first_sectors);
- BUG_ON(bi->bi_vcnt != 1);
+ BUG_ON(bi->bi_vcnt != 1 && bi->bi_vcnt != 0);
BUG_ON(bi->bi_idx != 0);
atomic_set(&bp->cnt, 3);
bp->error = 0;
@@ -1511,17 +1485,22 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
bp->bio2.bi_size -= first_sectors << 9;
bp->bio1.bi_size = first_sectors << 9;
- bp->bv1 = bi->bi_io_vec[0];
- bp->bv2 = bi->bi_io_vec[0];
- bp->bv2.bv_offset += first_sectors << 9;
- bp->bv2.bv_len -= first_sectors << 9;
- bp->bv1.bv_len = first_sectors << 9;
+ if (bi->bi_vcnt != 0) {
+ bp->bv1 = bi->bi_io_vec[0];
+ bp->bv2 = bi->bi_io_vec[0];
+
+ if (bio_is_rw(bi)) {
+ bp->bv2.bv_offset += first_sectors << 9;
+ bp->bv2.bv_len -= first_sectors << 9;
+ bp->bv1.bv_len = first_sectors << 9;
+ }
- bp->bio1.bi_io_vec = &bp->bv1;
- bp->bio2.bi_io_vec = &bp->bv2;
+ bp->bio1.bi_io_vec = &bp->bv1;
+ bp->bio2.bi_io_vec = &bp->bv2;
- bp->bio1.bi_max_vecs = 1;
- bp->bio2.bi_max_vecs = 1;
+ bp->bio1.bi_max_vecs = 1;
+ bp->bio2.bi_max_vecs = 1;
+ }
bp->bio1.bi_end_io = bio_pair_end_1;
bp->bio2.bi_end_io = bio_pair_end_2;
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-03 22:49:09 +0000