#include <linux/swap.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
+#include <linux/uio.h>
#include <linux/iocontext.h>
#include <linux/slab.h>
#include <linux/init.h>
return bvec_slabs[idx].nr_vecs;
}
-void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx)
+void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
{
BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
if (idx == BIOVEC_MAX_IDX)
- mempool_free(bv, bs->bvec_pool);
+ mempool_free(bv, pool);
else {
struct biovec_slab *bvs = bvec_slabs + idx;
}
}
-struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
- struct bio_set *bs)
+struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
+ mempool_t *pool)
{
struct bio_vec *bvl;
*/
if (*idx == BIOVEC_MAX_IDX) {
fallback:
- bvl = mempool_alloc(bs->bvec_pool, gfp_mask);
+ bvl = mempool_alloc(pool, gfp_mask);
} else {
struct biovec_slab *bvs = bvec_slabs + *idx;
gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
__bio_free(bio);
if (bs) {
- if (bio_has_allocated_vec(bio))
- bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
+ if (bio_flagged(bio, BIO_OWNS_VEC))
+ bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio));
/*
* If we have front padding, adjust the bio pointer before freeing
}
EXPORT_SYMBOL(bio_reset);
+static void bio_alloc_rescue(struct work_struct *work)
+{
+ struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
+ struct bio *bio;
+
+ while (1) {
+ spin_lock(&bs->rescue_lock);
+ bio = bio_list_pop(&bs->rescue_list);
+ spin_unlock(&bs->rescue_lock);
+
+ if (!bio)
+ break;
+
+ generic_make_request(bio);
+ }
+}
+
+static void punt_bios_to_rescuer(struct bio_set *bs)
+{
+ struct bio_list punt, nopunt;
+ struct bio *bio;
+
+ /*
+ * In order to guarantee forward progress we must punt only bios that
+ * were allocated from this bio_set; otherwise, if there was a bio on
+ * there for a stacking driver higher up in the stack, processing it
+ * could require allocating bios from this bio_set, and doing that from
+ * our own rescuer would be bad.
+ *
+ * Since bio lists are singly linked, pop them all instead of trying to
+ * remove from the middle of the list:
+ */
+
+ bio_list_init(&punt);
+ bio_list_init(&nopunt);
+
+ while ((bio = bio_list_pop(current->bio_list)))
+ bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
+
+ *current->bio_list = nopunt;
+
+ spin_lock(&bs->rescue_lock);
+ bio_list_merge(&bs->rescue_list, &punt);
+ spin_unlock(&bs->rescue_lock);
+
+ queue_work(bs->rescue_workqueue, &bs->rescue_work);
+}
+
/**
* bio_alloc_bioset - allocate a bio for I/O
* @gfp_mask: the GFP_ mask given to the slab allocator
* previously allocated bio for IO before attempting to allocate a new one.
* Failure to do so can cause deadlocks under memory pressure.
*
+ * Note that when running under generic_make_request() (i.e. any block
+ * driver), bios are not submitted until after you return - see the code in
+ * generic_make_request() that converts recursion into iteration, to prevent
+ * stack overflows.
+ *
+ * This would normally mean allocating multiple bios under
+ * generic_make_request() would be susceptible to deadlocks, but we have
+ * deadlock avoidance code that resubmits any blocked bios from a rescuer
+ * thread.
+ *
+ * However, we do not guarantee forward progress for allocations from other
+ * mempools. Doing multiple allocations from the same mempool under
+ * generic_make_request() should be avoided - instead, use bio_set's front_pad
+ * for per bio allocations.
+ *
* 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)
{
+ gfp_t saved_gfp = gfp_mask;
unsigned front_pad;
unsigned inline_vecs;
unsigned long idx = BIO_POOL_NONE;
front_pad = 0;
inline_vecs = nr_iovecs;
} else {
+ /*
+ * generic_make_request() converts recursion to iteration; this
+ * means if we're running beneath it, any bios we allocate and
+ * submit will not be submitted (and thus freed) until after we
+ * return.
+ *
+ * This exposes us to a potential deadlock if we allocate
+ * multiple bios from the same bio_set() while running
+ * underneath generic_make_request(). If we were to allocate
+ * multiple bios (say a stacking block driver that was splitting
+ * bios), we would deadlock if we exhausted the mempool's
+ * reserve.
+ *
+ * We solve this, and guarantee forward progress, with a rescuer
+ * workqueue per bio_set. If we go to allocate and there are
+ * bios on current->bio_list, we first try the allocation
+ * without __GFP_WAIT; if that fails, we punt those bios we
+ * would be blocking to the rescuer workqueue before we retry
+ * with the original gfp_flags.
+ */
+
+ if (current->bio_list && !bio_list_empty(current->bio_list))
+ gfp_mask &= ~__GFP_WAIT;
+
p = mempool_alloc(bs->bio_pool, gfp_mask);
+ if (!p && gfp_mask != saved_gfp) {
+ punt_bios_to_rescuer(bs);
+ gfp_mask = saved_gfp;
+ p = mempool_alloc(bs->bio_pool, gfp_mask);
+ }
+
front_pad = bs->front_pad;
inline_vecs = BIO_INLINE_VECS;
}
bio_init(bio);
if (nr_iovecs > inline_vecs) {
- bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ if (!bvl && gfp_mask != saved_gfp) {
+ punt_bios_to_rescuer(bs);
+ gfp_mask = saved_gfp;
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ }
+
if (unlikely(!bvl))
goto err_free;
+
+ bio->bi_flags |= 1 << BIO_OWNS_VEC;
} else if (nr_iovecs) {
bvl = bio->bi_inline_vecs;
}
}
EXPORT_SYMBOL(bio_add_page);
+struct submit_bio_ret {
+ struct completion event;
+ int error;
+};
+
+static void submit_bio_wait_endio(struct bio *bio, int error)
+{
+ struct submit_bio_ret *ret = bio->bi_private;
+
+ ret->error = error;
+ complete(&ret->event);
+}
+
+/**
+ * submit_bio_wait - submit a bio, and wait until it completes
+ * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead)
+ * @bio: The &struct bio which describes the I/O
+ *
+ * Simple wrapper around submit_bio(). Returns 0 on success, or the error from
+ * bio_endio() on failure.
+ */
+int submit_bio_wait(int rw, struct bio *bio)
+{
+ struct submit_bio_ret ret;
+
+ rw |= REQ_SYNC;
+ init_completion(&ret.event);
+ bio->bi_private = &ret;
+ bio->bi_end_io = submit_bio_wait_endio;
+ submit_bio(rw, bio);
+ wait_for_completion(&ret.event);
+
+ return ret.error;
+}
+EXPORT_SYMBOL(submit_bio_wait);
+
+/**
+ * bio_advance - increment/complete a bio by some number of bytes
+ * @bio: bio to advance
+ * @bytes: number of bytes to complete
+ *
+ * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
+ * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
+ * be updated on the last bvec as well.
+ *
+ * @bio will then represent the remaining, uncompleted portion of the io.
+ */
+void bio_advance(struct bio *bio, unsigned bytes)
+{
+ if (bio_integrity(bio))
+ bio_integrity_advance(bio, bytes);
+
+ bio->bi_sector += bytes >> 9;
+ bio->bi_size -= bytes;
+
+ if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
+ return;
+
+ while (bytes) {
+ if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
+ WARN_ONCE(1, "bio idx %d >= vcnt %d\n",
+ bio->bi_idx, bio->bi_vcnt);
+ break;
+ }
+
+ if (bytes >= bio_iovec(bio)->bv_len) {
+ bytes -= bio_iovec(bio)->bv_len;
+ bio->bi_idx++;
+ } else {
+ bio_iovec(bio)->bv_len -= bytes;
+ bio_iovec(bio)->bv_offset += bytes;
+ bytes = 0;
+ }
+ }
+}
+EXPORT_SYMBOL(bio_advance);
+
+/**
+ * bio_alloc_pages - allocates a single page for each bvec in a bio
+ * @bio: bio to allocate pages for
+ * @gfp_mask: flags for allocation
+ *
+ * Allocates pages up to @bio->bi_vcnt.
+ *
+ * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
+ * freed.
+ */
+int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
+{
+ int i;
+ struct bio_vec *bv;
+
+ bio_for_each_segment_all(bv, bio, i) {
+ bv->bv_page = alloc_page(gfp_mask);
+ if (!bv->bv_page) {
+ while (--bv >= bio->bi_io_vec)
+ __free_page(bv->bv_page);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(bio_alloc_pages);
+
+/**
+ * bio_copy_data - copy contents of data buffers from one chain of bios to
+ * another
+ * @src: source bio list
+ * @dst: destination bio list
+ *
+ * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats
+ * @src and @dst as linked lists of bios.
+ *
+ * Stops when it reaches the end of either @src or @dst - that is, copies
+ * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
+ */
+void bio_copy_data(struct bio *dst, struct bio *src)
+{
+ struct bio_vec *src_bv, *dst_bv;
+ unsigned src_offset, dst_offset, bytes;
+ void *src_p, *dst_p;
+
+ src_bv = bio_iovec(src);
+ dst_bv = bio_iovec(dst);
+
+ src_offset = src_bv->bv_offset;
+ dst_offset = dst_bv->bv_offset;
+
+ while (1) {
+ if (src_offset == src_bv->bv_offset + src_bv->bv_len) {
+ src_bv++;
+ if (src_bv == bio_iovec_idx(src, src->bi_vcnt)) {
+ src = src->bi_next;
+ if (!src)
+ break;
+
+ src_bv = bio_iovec(src);
+ }
+
+ src_offset = src_bv->bv_offset;
+ }
+
+ if (dst_offset == dst_bv->bv_offset + dst_bv->bv_len) {
+ dst_bv++;
+ if (dst_bv == bio_iovec_idx(dst, dst->bi_vcnt)) {
+ dst = dst->bi_next;
+ if (!dst)
+ break;
+
+ dst_bv = bio_iovec(dst);
+ }
+
+ dst_offset = dst_bv->bv_offset;
+ }
+
+ bytes = min(dst_bv->bv_offset + dst_bv->bv_len - dst_offset,
+ src_bv->bv_offset + src_bv->bv_len - src_offset);
+
+ src_p = kmap_atomic(src_bv->bv_page);
+ dst_p = kmap_atomic(dst_bv->bv_page);
+
+ memcpy(dst_p + dst_offset,
+ src_p + src_offset,
+ bytes);
+
+ kunmap_atomic(dst_p);
+ kunmap_atomic(src_p);
+
+ src_offset += bytes;
+ dst_offset += bytes;
+ }
+}
+EXPORT_SYMBOL(bio_copy_data);
+
struct bio_map_data {
struct bio_vec *iovecs;
struct sg_iovec *sgvecs;
int iov_idx = 0;
unsigned int iov_off = 0;
- __bio_for_each_segment(bvec, bio, i, 0) {
+ bio_for_each_segment_all(bvec, bio, i) {
char *bv_addr = page_address(bvec->bv_page);
unsigned int bv_len = iovecs[i].bv_len;
int bio_uncopy_user(struct bio *bio)
{
struct bio_map_data *bmd = bio->bi_private;
- int ret = 0;
+ struct bio_vec *bvec;
+ int ret = 0, i;
- if (!bio_flagged(bio, BIO_NULL_MAPPED))
- ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
- bmd->nr_sgvecs, bio_data_dir(bio) == READ,
- 0, bmd->is_our_pages);
+ if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
+ /*
+ * if we're in a workqueue, the request is orphaned, so
+ * don't copy into a random user address space, just free.
+ */
+ if (current->mm)
+ ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
+ bmd->nr_sgvecs, bio_data_dir(bio) == READ,
+ 0, bmd->is_our_pages);
+ else if (bmd->is_our_pages)
+ bio_for_each_segment_all(bvec, bio, i)
+ __free_page(bvec->bv_page);
+ }
bio_free_map_data(bmd);
bio_put(bio);
return ret;
return bio;
cleanup:
if (!map_data)
- bio_for_each_segment(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i)
__free_page(bvec->bv_page);
bio_put(bio);
/*
* make sure we dirty pages we wrote to
*/
- __bio_for_each_segment(bvec, bio, i, 0) {
+ bio_for_each_segment_all(bvec, bio, i) {
if (bio_data_dir(bio) == READ)
set_page_dirty_lock(bvec->bv_page);
int i;
char *p = bmd->sgvecs[0].iov_base;
- __bio_for_each_segment(bvec, bio, i, 0) {
+ bio_for_each_segment_all(bvec, bio, i) {
char *addr = page_address(bvec->bv_page);
int len = bmd->iovecs[i].bv_len;
if (!reading) {
void *p = data;
- bio_for_each_segment(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i) {
char *addr = page_address(bvec->bv_page);
memcpy(addr, p, bvec->bv_len);
*/
void bio_set_pages_dirty(struct bio *bio)
{
- struct bio_vec *bvec = bio->bi_io_vec;
+ struct bio_vec *bvec;
int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].bv_page;
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
if (page && !PageCompound(page))
set_page_dirty_lock(page);
static void bio_release_pages(struct bio *bio)
{
- struct bio_vec *bvec = bio->bi_io_vec;
+ struct bio_vec *bvec;
int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].bv_page;
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
if (page)
put_page(page);
void bio_check_pages_dirty(struct bio *bio)
{
- struct bio_vec *bvec = bio->bi_io_vec;
+ struct bio_vec *bvec;
int nr_clean_pages = 0;
int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].bv_page;
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
if (PageDirty(page) || PageCompound(page)) {
page_cache_release(page);
- bvec[i].bv_page = NULL;
+ bvec->bv_page = NULL;
} else {
nr_clean_pages++;
}
trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
bi->bi_sector + first_sectors);
- BUG_ON(bi->bi_vcnt != 1 && bi->bi_vcnt != 0);
- BUG_ON(bi->bi_idx != 0);
+ BUG_ON(bio_segments(bi) > 1);
atomic_set(&bp->cnt, 3);
bp->error = 0;
bp->bio1 = *bi;
bp->bio1.bi_size = first_sectors << 9;
if (bi->bi_vcnt != 0) {
- bp->bv1 = bi->bi_io_vec[0];
- bp->bv2 = bi->bi_io_vec[0];
+ bp->bv1 = *bio_iovec(bi);
+ bp->bv2 = *bio_iovec(bi);
if (bio_is_rw(bi)) {
bp->bv2.bv_offset += first_sectors << 9;
if (index >= bio->bi_idx)
index = bio->bi_vcnt - 1;
- __bio_for_each_segment(bv, bio, i, 0) {
+ bio_for_each_segment_all(bv, bio, i) {
if (i == index) {
if (offset > bv->bv_offset)
sectors += (offset - bv->bv_offset) / sector_sz;
* create memory pools for biovec's in a bio_set.
* use the global biovec slabs created for general use.
*/
-static int biovec_create_pools(struct bio_set *bs, int pool_entries)
+mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries)
{
struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
- bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab);
- if (!bs->bvec_pool)
- return -ENOMEM;
-
- return 0;
-}
-
-static void biovec_free_pools(struct bio_set *bs)
-{
- mempool_destroy(bs->bvec_pool);
+ return mempool_create_slab_pool(pool_entries, bp->slab);
}
void bioset_free(struct bio_set *bs)
{
+ if (bs->rescue_workqueue)
+ destroy_workqueue(bs->rescue_workqueue);
+
if (bs->bio_pool)
mempool_destroy(bs->bio_pool);
+ if (bs->bvec_pool)
+ mempool_destroy(bs->bvec_pool);
+
bioset_integrity_free(bs);
- biovec_free_pools(bs);
bio_put_slab(bs);
kfree(bs);
bs->front_pad = front_pad;
+ spin_lock_init(&bs->rescue_lock);
+ bio_list_init(&bs->rescue_list);
+ INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
+
bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
if (!bs->bio_slab) {
kfree(bs);
if (!bs->bio_pool)
goto bad;
- if (!biovec_create_pools(bs, pool_size))
- return bs;
+ bs->bvec_pool = biovec_create_pool(bs, pool_size);
+ if (!bs->bvec_pool)
+ goto bad;
+
+ bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
+ if (!bs->rescue_workqueue)
+ goto bad;
+ return bs;
bad:
bioset_free(bs);
return NULL;
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff