X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=fs%2Fbio.c;h=8f93e939f21375abe2c205fd2783c319098cc87f;hb=ba2397efe10ba728c7ff22b179e218c292227c13;hp=7d81a93afd480c9d9f0335c208f130946b1dc259;hpb=c87ff94333642ce3db4fc0857ad1f723cb42c1dd;p=powerpc.git diff --git a/fs/bio.c b/fs/bio.c index 7d81a93afd..8f93e939f2 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2001 Jens Axboe + * Copyright (C) 2001 Jens Axboe * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -25,11 +25,12 @@ #include #include #include +#include #include /* for struct sg_iovec */ #define BIO_POOL_SIZE 256 -static kmem_cache_t *bio_slab; +static kmem_cache_t *bio_slab __read_mostly; #define BIOVEC_NR_POOLS 6 @@ -38,7 +39,7 @@ static kmem_cache_t *bio_slab; * basically we just need to survive */ #define BIO_SPLIT_ENTRIES 8 -mempool_t *bio_split_pool; +mempool_t *bio_split_pool __read_mostly; struct biovec_slab { int nr_vecs; @@ -123,9 +124,10 @@ static void bio_fs_destructor(struct bio *bio) bio_free(bio, fs_bio_set); } -inline void bio_init(struct bio *bio) +void bio_init(struct bio *bio) { bio->bi_next = NULL; + bio->bi_bdev = NULL; bio->bi_flags = 1 << BIO_UPTODATE; bio->bi_rw = 0; bio->bi_vcnt = 0; @@ -252,7 +254,7 @@ inline int bio_hw_segments(request_queue_t *q, struct bio *bio) * the actual data it points to. Reference count of returned * bio will be one. */ -inline void __bio_clone(struct bio *bio, struct bio *bio_src) +void __bio_clone(struct bio *bio, struct bio *bio_src) { request_queue_t *q = bdev_get_queue(bio_src->bi_bdev); @@ -313,7 +315,8 @@ int bio_get_nr_vecs(struct block_device *bdev) } static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page - *page, unsigned int len, unsigned int offset) + *page, unsigned int len, unsigned int offset, + unsigned short max_sectors) { int retried_segments = 0; struct bio_vec *bvec; @@ -324,10 +327,31 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page if (unlikely(bio_flagged(bio, BIO_CLONED))) return 0; - if (bio->bi_vcnt >= bio->bi_max_vecs) + if (((bio->bi_size + len) >> 9) > max_sectors) return 0; - if (((bio->bi_size + len) >> 9) > q->max_sectors) + /* + * 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) { + struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; + + if (page == prev->bv_page && + offset == prev->bv_offset + prev->bv_len) { + prev->bv_len += len; + if (q->merge_bvec_fn && + q->merge_bvec_fn(q, bio, prev) < len) { + prev->bv_len -= len; + return 0; + } + + goto done; + } + } + + if (bio->bi_vcnt >= bio->bi_max_vecs) return 0; /* @@ -381,10 +405,31 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page bio->bi_vcnt++; bio->bi_phys_segments++; bio->bi_hw_segments++; + done: bio->bi_size += len; return len; } +/** + * 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 + * smaller than 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(request_queue_t *q, struct bio *bio, struct page *page, + unsigned int len, unsigned int offset) +{ + return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); +} + /** * bio_add_page - attempt to add page to bio * @bio: destination bio @@ -401,8 +446,8 @@ static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page int bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { - return __bio_add_page(bdev_get_queue(bio->bi_bdev), bio, page, - len, offset); + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + return __bio_add_page(q, bio, page, len, offset, q->max_sectors); } struct bio_map_data { @@ -514,7 +559,7 @@ struct bio *bio_copy_user(request_queue_t *q, unsigned long uaddr, break; } - if (__bio_add_page(q, bio, page, bytes, 0) < bytes) { + if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { ret = -EINVAL; break; } @@ -591,12 +636,10 @@ static struct bio *__bio_map_user_iov(request_queue_t *q, return ERR_PTR(-ENOMEM); ret = -ENOMEM; - pages = kmalloc(nr_pages * sizeof(struct page *), GFP_KERNEL); + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL); if (!pages) goto out; - memset(pages, 0, nr_pages * sizeof(struct page *)); - for (i = 0; i < iov_count; i++) { unsigned long uaddr = (unsigned long)iov[i].iov_base; unsigned long len = iov[i].iov_len; @@ -611,9 +654,10 @@ static struct bio *__bio_map_user_iov(request_queue_t *q, write_to_vm, 0, &pages[cur_page], NULL); up_read(¤t->mm->mmap_sem); - if (ret < local_nr_pages) + if (ret < local_nr_pages) { + ret = -EFAULT; goto out_unmap; - + } offset = uaddr & ~PAGE_MASK; for (j = cur_page; j < page_limit; j++) { @@ -628,7 +672,8 @@ static struct bio *__bio_map_user_iov(request_queue_t *q, /* * sorry... */ - if (__bio_add_page(q, bio, pages[j], bytes, offset) < bytes) + if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < + bytes) break; len -= bytes; @@ -778,7 +823,7 @@ static int bio_map_kern_endio(struct bio *bio, unsigned int bytes_done, int err) static struct bio *__bio_map_kern(request_queue_t *q, void *data, - unsigned int len, unsigned int gfp_mask) + unsigned int len, gfp_t gfp_mask) { unsigned long kaddr = (unsigned long)data; unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; @@ -801,8 +846,8 @@ static struct bio *__bio_map_kern(request_queue_t *q, void *data, if (bytes > len) bytes = len; - if (__bio_add_page(q, bio, virt_to_page(data), bytes, - offset) < bytes) + if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, + offset) < bytes) break; data += bytes; @@ -825,7 +870,7 @@ static struct bio *__bio_map_kern(request_queue_t *q, void *data, * device. Returns an error pointer in case of error. */ struct bio *bio_map_kern(request_queue_t *q, void *data, unsigned int len, - unsigned int gfp_mask) + gfp_t gfp_mask) { struct bio *bio; @@ -1050,6 +1095,9 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) if (!bp) return bp; + blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi, + bi->bi_sector + first_sectors); + BUG_ON(bi->bi_vcnt != 1); BUG_ON(bi->bi_idx != 0); atomic_set(&bp->cnt, 3); @@ -1069,6 +1117,9 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) 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_end_io = bio_pair_end_1; bp->bio2.bi_end_io = bio_pair_end_2; @@ -1078,16 +1129,6 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) return bp; } -static void *bio_pair_alloc(gfp_t gfp_flags, void *data) -{ - return kmalloc(sizeof(struct bio_pair), gfp_flags); -} - -static void bio_pair_free(void *bp, void *data) -{ - kfree(bp); -} - /* * create memory pools for biovec's in a bio_set. @@ -1101,11 +1142,10 @@ static int biovec_create_pools(struct bio_set *bs, int pool_entries, int scale) struct biovec_slab *bp = bvec_slabs + i; mempool_t **bvp = bs->bvec_pools + i; - if (i >= scale) + if (pool_entries > 1 && i >= scale) pool_entries >>= 1; - *bvp = mempool_create(pool_entries, mempool_alloc_slab, - mempool_free_slab, bp->slab); + *bvp = mempool_create_slab_pool(pool_entries, bp->slab); if (!*bvp) return -ENOMEM; } @@ -1137,15 +1177,12 @@ void bioset_free(struct bio_set *bs) struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size, int scale) { - struct bio_set *bs = kmalloc(sizeof(*bs), GFP_KERNEL); + struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL); if (!bs) return NULL; - memset(bs, 0, sizeof(*bs)); - bs->bio_pool = mempool_create(bio_pool_size, mempool_alloc_slab, - mempool_free_slab, bio_slab); - + bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab); if (!bs->bio_pool) goto bad; @@ -1198,18 +1235,18 @@ static int __init init_bio(void) scale = 4; /* - * scale number of entries + * Limit number of entries reserved -- mempools are only used when + * the system is completely unable to allocate memory, so we only + * need enough to make progress. */ - bvec_pool_entries = megabytes * 2; - if (bvec_pool_entries > 256) - bvec_pool_entries = 256; + bvec_pool_entries = 1 + scale; fs_bio_set = bioset_create(BIO_POOL_SIZE, bvec_pool_entries, scale); if (!fs_bio_set) panic("bio: can't allocate bios\n"); - bio_split_pool = mempool_create(BIO_SPLIT_ENTRIES, - bio_pair_alloc, bio_pair_free, NULL); + bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, + sizeof(struct bio_pair)); if (!bio_split_pool) panic("bio: can't create split pool\n"); @@ -1228,6 +1265,7 @@ 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); EXPORT_SYMBOL(bio_map_user); EXPORT_SYMBOL(bio_unmap_user);