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author | 2011-12-28 19:21:45 +0200 | |
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committer | 2012-01-08 10:43:13 +0200 | |
commit | 724577ca355795b0a25c93ccbeee927871ca1a77 (patch) | |
tree | ca3cdb4e7f1b9ab7963503227e1ca555c3535b3f | |
parent | ore: fix BUG_ON, too few sgs when reading (diff) | |
download | linux-724577ca355795b0a25c93ccbeee927871ca1a77.tar.gz linux-724577ca355795b0a25c93ccbeee927871ca1a77.tar.bz2 linux-724577ca355795b0a25c93ccbeee927871ca1a77.zip |
ore: Must support none-PAGE-aligned IO
NFS might send us offsets that are not PAGE aligned. So
we must read in the reminder of the first/last pages, in cases
we need it for Parity calculations.
We only add an sg segments to read the partial page. But
we don't mark it as read=true because it is a lock-for-write
page.
TODO: In some cases (IO spans a single unit) we can just
adjust the raid_unit offset/length, but this is left for
later Kernels.
[Bug in 3.2.0 Kernel]
CC: Stable Tree <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
-rw-r--r-- | fs/exofs/ore_raid.c | 72 |
1 files changed, 60 insertions, 12 deletions
diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c index 414a2dfd9500..d222c77cfa1b 100644 --- a/fs/exofs/ore_raid.c +++ b/fs/exofs/ore_raid.c @@ -328,8 +328,8 @@ static int _alloc_read_4_write(struct ore_io_state *ios) /* @si contains info of the to-be-inserted page. Update of @si should be * maintained by caller. Specificaly si->dev, si->obj_offset, ... */ -static int _add_to_read_4_write(struct ore_io_state *ios, - struct ore_striping_info *si, struct page *page) +static int _add_to_r4w(struct ore_io_state *ios, struct ore_striping_info *si, + struct page *page, unsigned pg_len) { struct request_queue *q; struct ore_per_dev_state *per_dev; @@ -366,17 +366,60 @@ static int _add_to_read_4_write(struct ore_io_state *ios, _ore_add_sg_seg(per_dev, gap, true); } q = osd_request_queue(ore_comp_dev(read_ios->oc, per_dev->dev)); - added_len = bio_add_pc_page(q, per_dev->bio, page, PAGE_SIZE, 0); - if (unlikely(added_len != PAGE_SIZE)) { + added_len = bio_add_pc_page(q, per_dev->bio, page, pg_len, + si->obj_offset % PAGE_SIZE); + if (unlikely(added_len != pg_len)) { ORE_DBGMSG("Failed to bio_add_pc_page bi_vcnt=%d\n", per_dev->bio->bi_vcnt); return -ENOMEM; } - per_dev->length += PAGE_SIZE; + per_dev->length += pg_len; return 0; } +/* read the beginning of an unaligned first page */ +static int _add_to_r4w_first_page(struct ore_io_state *ios, struct page *page) +{ + struct ore_striping_info si; + unsigned pg_len; + + ore_calc_stripe_info(ios->layout, ios->offset, 0, &si); + + pg_len = si.obj_offset % PAGE_SIZE; + si.obj_offset -= pg_len; + + ORE_DBGMSG("offset=0x%llx len=0x%x index=0x%lx dev=%x\n", + _LLU(si.obj_offset), pg_len, page->index, si.dev); + + return _add_to_r4w(ios, &si, page, pg_len); +} + +/* read the end of an incomplete last page */ +static int _add_to_r4w_last_page(struct ore_io_state *ios, u64 *offset) +{ + struct ore_striping_info si; + struct page *page; + unsigned pg_len, p, c; + + ore_calc_stripe_info(ios->layout, *offset, 0, &si); + + p = si.unit_off / PAGE_SIZE; + c = _dev_order(ios->layout->group_width * ios->layout->mirrors_p1, + ios->layout->mirrors_p1, si.par_dev, si.dev); + page = ios->sp2d->_1p_stripes[p].pages[c]; + + pg_len = PAGE_SIZE - (si.unit_off % PAGE_SIZE); + *offset += pg_len; + + ORE_DBGMSG("p=%d, c=%d next-offset=0x%llx len=0x%x dev=%x par_dev=%d\n", + p, c, _LLU(*offset), pg_len, si.dev, si.par_dev); + + BUG_ON(!page); + + return _add_to_r4w(ios, &si, page, pg_len); +} + static void _mark_read4write_pages_uptodate(struct ore_io_state *ios, int ret) { struct bio_vec *bv; @@ -444,9 +487,13 @@ static int _read_4_write(struct ore_io_state *ios) struct page **pp = &_1ps->pages[c]; bool uptodate; - if (*pp) + if (*pp) { + if (ios->offset % PAGE_SIZE) + /* Read the remainder of the page */ + _add_to_r4w_first_page(ios, *pp); /* to-be-written pages start here */ goto read_last_stripe; + } *pp = ios->r4w->get_page(ios->private, offset, &uptodate); @@ -454,7 +501,7 @@ static int _read_4_write(struct ore_io_state *ios) return -ENOMEM; if (!uptodate) - _add_to_read_4_write(ios, &read_si, *pp); + _add_to_r4w(ios, &read_si, *pp, PAGE_SIZE); /* Mark read-pages to be cache_released */ _1ps->page_is_read[c] = true; @@ -465,8 +512,11 @@ static int _read_4_write(struct ore_io_state *ios) } read_last_stripe: - offset = ios->offset + (ios->length + PAGE_SIZE - 1) / - PAGE_SIZE * PAGE_SIZE; + offset = ios->offset + ios->length; + if (offset % PAGE_SIZE) + _add_to_r4w_last_page(ios, &offset); + /* offset will be aligned to next page */ + last_stripe_end = div_u64(offset + bytes_in_stripe - 1, bytes_in_stripe) * bytes_in_stripe; if (offset == last_stripe_end) /* Optimize for the aligned case */ @@ -503,7 +553,7 @@ read_last_stripe: /* Mark read-pages to be cache_released */ _1ps->page_is_read[c] = true; if (!uptodate) - _add_to_read_4_write(ios, &read_si, page); + _add_to_r4w(ios, &read_si, page, PAGE_SIZE); } offset += PAGE_SIZE; @@ -616,8 +666,6 @@ int _ore_post_alloc_raid_stuff(struct ore_io_state *ios) return -ENOMEM; } - BUG_ON(ios->offset % PAGE_SIZE); - /* Round io down to last full strip */ first_stripe = div_u64(ios->offset, stripe_size); last_stripe = div_u64(ios->offset + ios->length, stripe_size); |