diff options
author | Boaz Harrosh <bharrosh@panasas.com> | 2010-01-28 16:24:06 (GMT) |
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committer | Boaz Harrosh <bharrosh@panasas.com> | 2010-02-28 11:44:42 (GMT) |
commit | 86093aaff5be5b214613eb60553e236bdb389c84 (patch) | |
tree | 64993f3fff8b60408441e8912aa5690346108492 /fs/exofs/ios.c | |
parent | 5d952b8391692553c31e620a92d6e09262a9a307 (diff) | |
download | linux-86093aaff5be5b214613eb60553e236bdb389c84.tar.xz |
exofs: convert io_state to use pages array instead of bio at input
* inode.c operations are full-pages based, and not actually
true scatter-gather
* Lets us use more pages at once upto 512 (from 249) in 64 bit
* Brings us much much closer to be able to use exofs's io_state engine
from objlayout driver. (Once I decide where to put the common code)
After RAID0 patch the outer (input) bio was never used as a bio, but
was simply a page carrier into the raid engine. Even in the simple
mirror/single-dev arrangement pages info was copied into a second bio.
It is now easer to just pass a pages array into the io_state and prepare
bio(s) once.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Diffstat (limited to 'fs/exofs/ios.c')
-rw-r--r-- | fs/exofs/ios.c | 46 |
1 files changed, 26 insertions, 20 deletions
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c index 6e446b2..263052c 100644 --- a/fs/exofs/ios.c +++ b/fs/exofs/ios.c @@ -283,10 +283,11 @@ static void _offset_dev_unit_off(struct exofs_io_state *ios, u64 file_offset, *dev = stripe_mod / stripe_unit * ios->layout->mirrors_p1; } -static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_bvec, - struct exofs_per_dev_state *per_dev, int cur_len) +static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_pg, + unsigned pgbase, struct exofs_per_dev_state *per_dev, + int cur_len) { - unsigned bv = *cur_bvec; + unsigned pg = *cur_pg; struct request_queue *q = osd_request_queue(exofs_ios_od(ios, per_dev->dev)); @@ -295,7 +296,7 @@ static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_bvec, if (per_dev->bio == NULL) { unsigned pages_in_stripe = ios->layout->group_width * (ios->layout->stripe_unit / PAGE_SIZE); - unsigned bio_size = (ios->bio->bi_vcnt + pages_in_stripe) / + unsigned bio_size = (ios->nr_pages + pages_in_stripe) / ios->layout->group_width; per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size); @@ -307,21 +308,22 @@ static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_bvec, } while (cur_len > 0) { - int added_len; - struct bio_vec *bvec = &ios->bio->bi_io_vec[bv]; + unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len); + unsigned added_len; - BUG_ON(ios->bio->bi_vcnt <= bv); - cur_len -= bvec->bv_len; + BUG_ON(ios->nr_pages <= pg); + cur_len -= pglen; - added_len = bio_add_pc_page(q, per_dev->bio, bvec->bv_page, - bvec->bv_len, bvec->bv_offset); - if (unlikely(bvec->bv_len != added_len)) + added_len = bio_add_pc_page(q, per_dev->bio, ios->pages[pg], + pglen, pgbase); + if (unlikely(pglen != added_len)) return -ENOMEM; - ++bv; + pgbase = 0; + ++pg; } BUG_ON(cur_len); - *cur_bvec = bv; + *cur_pg = pg; return 0; } @@ -332,10 +334,10 @@ static int _prepare_for_striping(struct exofs_io_state *ios) unsigned stripe_unit = ios->layout->stripe_unit; unsigned comp = 0; unsigned stripes = 0; - unsigned cur_bvec = 0; - int ret; + unsigned cur_pg = 0; + int ret = 0; - if (!ios->bio) { + if (!ios->pages) { if (ios->kern_buff) { struct exofs_per_dev_state *per_dev = &ios->per_dev[0]; unsigned unit_off; @@ -352,7 +354,7 @@ static int _prepare_for_striping(struct exofs_io_state *ios) while (length) { struct exofs_per_dev_state *per_dev = &ios->per_dev[comp]; - unsigned cur_len; + unsigned cur_len, page_off; if (!per_dev->length) { unsigned unit_off; @@ -362,11 +364,15 @@ static int _prepare_for_striping(struct exofs_io_state *ios) stripes++; cur_len = min_t(u64, stripe_unit - unit_off, length); offset += cur_len; + page_off = unit_off & ~PAGE_MASK; + BUG_ON(page_off != ios->pgbase); } else { cur_len = min_t(u64, stripe_unit, length); + page_off = 0; } - ret = _add_stripe_unit(ios, &cur_bvec, per_dev, cur_len); + ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev, + cur_len); if (unlikely(ret)) goto out; @@ -448,7 +454,7 @@ static int _sbi_write_mirror(struct exofs_io_state *ios, int cur_comp) per_dev->or = or; per_dev->offset = master_dev->offset; - if (ios->bio) { + if (ios->pages) { struct bio *bio; if (per_dev != master_dev) { @@ -541,7 +547,7 @@ static int _sbi_read_mirror(struct exofs_io_state *ios, unsigned cur_comp) } per_dev->or = or; - if (ios->bio) { + if (ios->pages) { osd_req_read(or, &ios->obj, per_dev->offset, per_dev->bio, per_dev->length); EXOFS_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx" |