From b916c5cd4d895a27b47a652648958f73e4f23ac6 Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Wed, 28 Sep 2011 11:55:51 +0300 Subject: ore: Only IO one group at a time (API change) Usually a single IO is confined to one group of devices (group_width) and at the boundary of a raid group it can spill into a second group. Current code would allocate a full device_table size array at each io_state so it can comply to requests that span two groups. Needless to say that is very wasteful, specially when device_table count can get very large (hundreds even thousands), while a group_width is usually 8 or 10. * Change ore API to trim on IO that spans two raid groups. The user passes offset+length to ore_get_rw_state, the ore might trim on that length if spanning a group boundary. The user must check ios->length or ios->nrpages to see how much IO will be preformed. It is the responsibility of the user to re-issue the reminder of the IO. * Modify exofs To copy spilled pages on to the next IO. This means one last kick is needed after all coalescing of pages is done. Signed-off-by: Boaz Harrosh --- fs/exofs/inode.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 85 insertions(+), 15 deletions(-) (limited to 'fs/exofs/inode.c') diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c index 61b2f7e5cdb..d87c1f7562f 100644 --- a/fs/exofs/inode.c +++ b/fs/exofs/inode.c @@ -259,6 +259,46 @@ static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw) } } +static int _maybe_not_all_in_one_io(struct ore_io_state *ios, + struct page_collect *pcol_src, struct page_collect *pcol) +{ + /* length was wrong or offset was not page aligned */ + BUG_ON(pcol_src->nr_pages < ios->nr_pages); + + if (pcol_src->nr_pages > ios->nr_pages) { + struct page **src_page; + unsigned pages_less = pcol_src->nr_pages - ios->nr_pages; + unsigned long len_less = pcol_src->length - ios->length; + unsigned i; + int ret; + + /* This IO was trimmed */ + pcol_src->nr_pages = ios->nr_pages; + pcol_src->length = ios->length; + + /* Left over pages are passed to the next io */ + pcol->expected_pages += pages_less; + pcol->nr_pages = pages_less; + pcol->length = len_less; + src_page = pcol_src->pages + pcol_src->nr_pages; + pcol->pg_first = (*src_page)->index; + + ret = pcol_try_alloc(pcol); + if (unlikely(ret)) + return ret; + + for (i = 0; i < pages_less; ++i) + pcol->pages[i] = *src_page++; + + EXOFS_DBGMSG("Length was adjusted nr_pages=0x%x " + "pages_less=0x%x expected_pages=0x%x " + "next_offset=0x%llx next_len=0x%lx\n", + pcol_src->nr_pages, pages_less, pcol->expected_pages, + pcol->pg_first * PAGE_SIZE, pcol->length); + } + return 0; +} + static int read_exec(struct page_collect *pcol) { struct exofs_i_info *oi = exofs_i(pcol->inode); @@ -280,7 +320,6 @@ static int read_exec(struct page_collect *pcol) ios = pcol->ios; ios->pages = pcol->pages; - ios->nr_pages = pcol->nr_pages; if (pcol->read_4_write) { ore_read(pcol->ios); @@ -296,17 +335,23 @@ static int read_exec(struct page_collect *pcol) *pcol_copy = *pcol; ios->done = readpages_done; ios->private = pcol_copy; + + /* pages ownership was passed to pcol_copy */ + _pcol_reset(pcol); + + ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol); + if (unlikely(ret)) + goto err; + + EXOFS_DBGMSG2("read_exec(0x%lx) offset=0x%llx length=0x%llx\n", + pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length)); + ret = ore_read(ios); if (unlikely(ret)) goto err; atomic_inc(&pcol->sbi->s_curr_pending); - EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n", - oi->one_comp.obj.id, _LLU(ios->offset), pcol->length); - - /* pages ownership was passed to pcol_copy */ - _pcol_reset(pcol); return 0; err: @@ -429,6 +474,10 @@ static int exofs_readpages(struct file *file, struct address_space *mapping, return ret; } + ret = read_exec(&pcol); + if (unlikely(ret)) + return ret; + return read_exec(&pcol); } @@ -519,7 +568,6 @@ static int write_exec(struct page_collect *pcol) ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, false, pcol->pg_first << PAGE_CACHE_SHIFT, pcol->length, &pcol->ios); - if (unlikely(ret)) goto err; @@ -534,10 +582,19 @@ static int write_exec(struct page_collect *pcol) ios = pcol->ios; ios->pages = pcol_copy->pages; - ios->nr_pages = pcol_copy->nr_pages; ios->done = writepages_done; ios->private = pcol_copy; + /* pages ownership was passed to pcol_copy */ + _pcol_reset(pcol); + + ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol); + if (unlikely(ret)) + goto err; + + EXOFS_DBGMSG2("write_exec(0x%lx) offset=0x%llx length=0x%llx\n", + pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length)); + ret = ore_write(ios); if (unlikely(ret)) { EXOFS_ERR("write_exec: ore_write() Failed\n"); @@ -545,11 +602,6 @@ static int write_exec(struct page_collect *pcol) } atomic_inc(&pcol->sbi->s_curr_pending); - EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n", - pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset), - pcol->length); - /* pages ownership was passed to pcol_copy */ - _pcol_reset(pcol); return 0; err: @@ -689,12 +741,30 @@ static int exofs_writepages(struct address_space *mapping, _pcol_init(&pcol, expected_pages, mapping->host); ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol); - if (ret) { + if (unlikely(ret)) { EXOFS_ERR("write_cache_pages => %d\n", ret); return ret; } - return write_exec(&pcol); + ret = write_exec(&pcol); + if (unlikely(ret)) + return ret; + + if (wbc->sync_mode == WB_SYNC_ALL) { + return write_exec(&pcol); /* pump the last reminder */ + } else if (pcol.nr_pages) { + /* not SYNC let the reminder join the next writeout */ + unsigned i; + + for (i = 0; i < pcol.nr_pages; i++) { + struct page *page = pcol.pages[i]; + + end_page_writeback(page); + set_page_dirty(page); + unlock_page(page); + } + } + return 0; } static int exofs_writepage(struct page *page, struct writeback_control *wbc) -- cgit v1.2.3