From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/nilfs2/page.c | 581 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 581 insertions(+) create mode 100644 kernel/fs/nilfs2/page.c (limited to 'kernel/fs/nilfs2/page.c') diff --git a/kernel/fs/nilfs2/page.c b/kernel/fs/nilfs2/page.c new file mode 100644 index 000000000..45d650add --- /dev/null +++ b/kernel/fs/nilfs2/page.c @@ -0,0 +1,581 @@ +/* + * page.c - buffer/page management specific to NILFS + * + * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Written by Ryusuke Konishi , + * Seiji Kihara . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "nilfs.h" +#include "page.h" +#include "mdt.h" + + +#define NILFS_BUFFER_INHERENT_BITS \ + ((1UL << BH_Uptodate) | (1UL << BH_Mapped) | (1UL << BH_NILFS_Node) | \ + (1UL << BH_NILFS_Volatile) | (1UL << BH_NILFS_Checked)) + +static struct buffer_head * +__nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index, + int blkbits, unsigned long b_state) + +{ + unsigned long first_block; + struct buffer_head *bh; + + if (!page_has_buffers(page)) + create_empty_buffers(page, 1 << blkbits, b_state); + + first_block = (unsigned long)index << (PAGE_CACHE_SHIFT - blkbits); + bh = nilfs_page_get_nth_block(page, block - first_block); + + touch_buffer(bh); + wait_on_buffer(bh); + return bh; +} + +struct buffer_head *nilfs_grab_buffer(struct inode *inode, + struct address_space *mapping, + unsigned long blkoff, + unsigned long b_state) +{ + int blkbits = inode->i_blkbits; + pgoff_t index = blkoff >> (PAGE_CACHE_SHIFT - blkbits); + struct page *page; + struct buffer_head *bh; + + page = grab_cache_page(mapping, index); + if (unlikely(!page)) + return NULL; + + bh = __nilfs_get_page_block(page, blkoff, index, blkbits, b_state); + if (unlikely(!bh)) { + unlock_page(page); + page_cache_release(page); + return NULL; + } + return bh; +} + +/** + * nilfs_forget_buffer - discard dirty state + * @inode: owner inode of the buffer + * @bh: buffer head of the buffer to be discarded + */ +void nilfs_forget_buffer(struct buffer_head *bh) +{ + struct page *page = bh->b_page; + const unsigned long clear_bits = + (1 << BH_Uptodate | 1 << BH_Dirty | 1 << BH_Mapped | + 1 << BH_Async_Write | 1 << BH_NILFS_Volatile | + 1 << BH_NILFS_Checked | 1 << BH_NILFS_Redirected); + + lock_buffer(bh); + set_mask_bits(&bh->b_state, clear_bits, 0); + if (nilfs_page_buffers_clean(page)) + __nilfs_clear_page_dirty(page); + + bh->b_blocknr = -1; + ClearPageUptodate(page); + ClearPageMappedToDisk(page); + unlock_buffer(bh); + brelse(bh); +} + +/** + * nilfs_copy_buffer -- copy buffer data and flags + * @dbh: destination buffer + * @sbh: source buffer + */ +void nilfs_copy_buffer(struct buffer_head *dbh, struct buffer_head *sbh) +{ + void *kaddr0, *kaddr1; + unsigned long bits; + struct page *spage = sbh->b_page, *dpage = dbh->b_page; + struct buffer_head *bh; + + kaddr0 = kmap_atomic(spage); + kaddr1 = kmap_atomic(dpage); + memcpy(kaddr1 + bh_offset(dbh), kaddr0 + bh_offset(sbh), sbh->b_size); + kunmap_atomic(kaddr1); + kunmap_atomic(kaddr0); + + dbh->b_state = sbh->b_state & NILFS_BUFFER_INHERENT_BITS; + dbh->b_blocknr = sbh->b_blocknr; + dbh->b_bdev = sbh->b_bdev; + + bh = dbh; + bits = sbh->b_state & ((1UL << BH_Uptodate) | (1UL << BH_Mapped)); + while ((bh = bh->b_this_page) != dbh) { + lock_buffer(bh); + bits &= bh->b_state; + unlock_buffer(bh); + } + if (bits & (1UL << BH_Uptodate)) + SetPageUptodate(dpage); + else + ClearPageUptodate(dpage); + if (bits & (1UL << BH_Mapped)) + SetPageMappedToDisk(dpage); + else + ClearPageMappedToDisk(dpage); +} + +/** + * nilfs_page_buffers_clean - check if a page has dirty buffers or not. + * @page: page to be checked + * + * nilfs_page_buffers_clean() returns zero if the page has dirty buffers. + * Otherwise, it returns non-zero value. + */ +int nilfs_page_buffers_clean(struct page *page) +{ + struct buffer_head *bh, *head; + + bh = head = page_buffers(page); + do { + if (buffer_dirty(bh)) + return 0; + bh = bh->b_this_page; + } while (bh != head); + return 1; +} + +void nilfs_page_bug(struct page *page) +{ + struct address_space *m; + unsigned long ino; + + if (unlikely(!page)) { + printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n"); + return; + } + + m = page->mapping; + ino = m ? m->host->i_ino : 0; + + printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx " + "mapping=%p ino=%lu\n", + page, atomic_read(&page->_count), + (unsigned long long)page->index, page->flags, m, ino); + + if (page_has_buffers(page)) { + struct buffer_head *bh, *head; + int i = 0; + + bh = head = page_buffers(page); + do { + printk(KERN_CRIT + " BH[%d] %p: cnt=%d block#=%llu state=0x%lx\n", + i++, bh, atomic_read(&bh->b_count), + (unsigned long long)bh->b_blocknr, bh->b_state); + bh = bh->b_this_page; + } while (bh != head); + } +} + +/** + * nilfs_copy_page -- copy the page with buffers + * @dst: destination page + * @src: source page + * @copy_dirty: flag whether to copy dirty states on the page's buffer heads. + * + * This function is for both data pages and btnode pages. The dirty flag + * should be treated by caller. The page must not be under i/o. + * Both src and dst page must be locked + */ +static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty) +{ + struct buffer_head *dbh, *dbufs, *sbh, *sbufs; + unsigned long mask = NILFS_BUFFER_INHERENT_BITS; + + BUG_ON(PageWriteback(dst)); + + sbh = sbufs = page_buffers(src); + if (!page_has_buffers(dst)) + create_empty_buffers(dst, sbh->b_size, 0); + + if (copy_dirty) + mask |= (1UL << BH_Dirty); + + dbh = dbufs = page_buffers(dst); + do { + lock_buffer(sbh); + lock_buffer(dbh); + dbh->b_state = sbh->b_state & mask; + dbh->b_blocknr = sbh->b_blocknr; + dbh->b_bdev = sbh->b_bdev; + sbh = sbh->b_this_page; + dbh = dbh->b_this_page; + } while (dbh != dbufs); + + copy_highpage(dst, src); + + if (PageUptodate(src) && !PageUptodate(dst)) + SetPageUptodate(dst); + else if (!PageUptodate(src) && PageUptodate(dst)) + ClearPageUptodate(dst); + if (PageMappedToDisk(src) && !PageMappedToDisk(dst)) + SetPageMappedToDisk(dst); + else if (!PageMappedToDisk(src) && PageMappedToDisk(dst)) + ClearPageMappedToDisk(dst); + + do { + unlock_buffer(sbh); + unlock_buffer(dbh); + sbh = sbh->b_this_page; + dbh = dbh->b_this_page; + } while (dbh != dbufs); +} + +int nilfs_copy_dirty_pages(struct address_space *dmap, + struct address_space *smap) +{ + struct pagevec pvec; + unsigned int i; + pgoff_t index = 0; + int err = 0; + + pagevec_init(&pvec, 0); +repeat: + if (!pagevec_lookup_tag(&pvec, smap, &index, PAGECACHE_TAG_DIRTY, + PAGEVEC_SIZE)) + return 0; + + for (i = 0; i < pagevec_count(&pvec); i++) { + struct page *page = pvec.pages[i], *dpage; + + lock_page(page); + if (unlikely(!PageDirty(page))) + NILFS_PAGE_BUG(page, "inconsistent dirty state"); + + dpage = grab_cache_page(dmap, page->index); + if (unlikely(!dpage)) { + /* No empty page is added to the page cache */ + err = -ENOMEM; + unlock_page(page); + break; + } + if (unlikely(!page_has_buffers(page))) + NILFS_PAGE_BUG(page, + "found empty page in dat page cache"); + + nilfs_copy_page(dpage, page, 1); + __set_page_dirty_nobuffers(dpage); + + unlock_page(dpage); + page_cache_release(dpage); + unlock_page(page); + } + pagevec_release(&pvec); + cond_resched(); + + if (likely(!err)) + goto repeat; + return err; +} + +/** + * nilfs_copy_back_pages -- copy back pages to original cache from shadow cache + * @dmap: destination page cache + * @smap: source page cache + * + * No pages must no be added to the cache during this process. + * This must be ensured by the caller. + */ +void nilfs_copy_back_pages(struct address_space *dmap, + struct address_space *smap) +{ + struct pagevec pvec; + unsigned int i, n; + pgoff_t index = 0; + int err; + + pagevec_init(&pvec, 0); +repeat: + n = pagevec_lookup(&pvec, smap, index, PAGEVEC_SIZE); + if (!n) + return; + index = pvec.pages[n - 1]->index + 1; + + for (i = 0; i < pagevec_count(&pvec); i++) { + struct page *page = pvec.pages[i], *dpage; + pgoff_t offset = page->index; + + lock_page(page); + dpage = find_lock_page(dmap, offset); + if (dpage) { + /* override existing page on the destination cache */ + WARN_ON(PageDirty(dpage)); + nilfs_copy_page(dpage, page, 0); + unlock_page(dpage); + page_cache_release(dpage); + } else { + struct page *page2; + + /* move the page to the destination cache */ + spin_lock_irq(&smap->tree_lock); + page2 = radix_tree_delete(&smap->page_tree, offset); + WARN_ON(page2 != page); + + smap->nrpages--; + spin_unlock_irq(&smap->tree_lock); + + spin_lock_irq(&dmap->tree_lock); + err = radix_tree_insert(&dmap->page_tree, offset, page); + if (unlikely(err < 0)) { + WARN_ON(err == -EEXIST); + page->mapping = NULL; + page_cache_release(page); /* for cache */ + } else { + page->mapping = dmap; + dmap->nrpages++; + if (PageDirty(page)) + radix_tree_tag_set(&dmap->page_tree, + offset, + PAGECACHE_TAG_DIRTY); + } + spin_unlock_irq(&dmap->tree_lock); + } + unlock_page(page); + } + pagevec_release(&pvec); + cond_resched(); + + goto repeat; +} + +/** + * nilfs_clear_dirty_pages - discard dirty pages in address space + * @mapping: address space with dirty pages for discarding + * @silent: suppress [true] or print [false] warning messages + */ +void nilfs_clear_dirty_pages(struct address_space *mapping, bool silent) +{ + struct pagevec pvec; + unsigned int i; + pgoff_t index = 0; + + pagevec_init(&pvec, 0); + + while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, + PAGEVEC_SIZE)) { + for (i = 0; i < pagevec_count(&pvec); i++) { + struct page *page = pvec.pages[i]; + + lock_page(page); + nilfs_clear_dirty_page(page, silent); + unlock_page(page); + } + pagevec_release(&pvec); + cond_resched(); + } +} + +/** + * nilfs_clear_dirty_page - discard dirty page + * @page: dirty page that will be discarded + * @silent: suppress [true] or print [false] warning messages + */ +void nilfs_clear_dirty_page(struct page *page, bool silent) +{ + struct inode *inode = page->mapping->host; + struct super_block *sb = inode->i_sb; + + BUG_ON(!PageLocked(page)); + + if (!silent) { + nilfs_warning(sb, __func__, + "discard page: offset %lld, ino %lu", + page_offset(page), inode->i_ino); + } + + ClearPageUptodate(page); + ClearPageMappedToDisk(page); + + if (page_has_buffers(page)) { + struct buffer_head *bh, *head; + const unsigned long clear_bits = + (1 << BH_Uptodate | 1 << BH_Dirty | 1 << BH_Mapped | + 1 << BH_Async_Write | 1 << BH_NILFS_Volatile | + 1 << BH_NILFS_Checked | 1 << BH_NILFS_Redirected); + + bh = head = page_buffers(page); + do { + lock_buffer(bh); + if (!silent) { + nilfs_warning(sb, __func__, + "discard block %llu, size %zu", + (u64)bh->b_blocknr, bh->b_size); + } + set_mask_bits(&bh->b_state, clear_bits, 0); + unlock_buffer(bh); + } while (bh = bh->b_this_page, bh != head); + } + + __nilfs_clear_page_dirty(page); +} + +unsigned nilfs_page_count_clean_buffers(struct page *page, + unsigned from, unsigned to) +{ + unsigned block_start, block_end; + struct buffer_head *bh, *head; + unsigned nc = 0; + + for (bh = head = page_buffers(page), block_start = 0; + bh != head || !block_start; + block_start = block_end, bh = bh->b_this_page) { + block_end = block_start + bh->b_size; + if (block_end > from && block_start < to && !buffer_dirty(bh)) + nc++; + } + return nc; +} + +void nilfs_mapping_init(struct address_space *mapping, struct inode *inode) +{ + mapping->host = inode; + mapping->flags = 0; + mapping_set_gfp_mask(mapping, GFP_NOFS); + mapping->private_data = NULL; + mapping->a_ops = &empty_aops; +} + +/* + * NILFS2 needs clear_page_dirty() in the following two cases: + * + * 1) For B-tree node pages and data pages of the dat/gcdat, NILFS2 clears + * page dirty flags when it copies back pages from the shadow cache + * (gcdat->{i_mapping,i_btnode_cache}) to its original cache + * (dat->{i_mapping,i_btnode_cache}). + * + * 2) Some B-tree operations like insertion or deletion may dispose buffers + * in dirty state, and this needs to cancel the dirty state of their pages. + */ +int __nilfs_clear_page_dirty(struct page *page) +{ + struct address_space *mapping = page->mapping; + + if (mapping) { + spin_lock_irq(&mapping->tree_lock); + if (test_bit(PG_dirty, &page->flags)) { + radix_tree_tag_clear(&mapping->page_tree, + page_index(page), + PAGECACHE_TAG_DIRTY); + spin_unlock_irq(&mapping->tree_lock); + return clear_page_dirty_for_io(page); + } + spin_unlock_irq(&mapping->tree_lock); + return 0; + } + return TestClearPageDirty(page); +} + +/** + * nilfs_find_uncommitted_extent - find extent of uncommitted data + * @inode: inode + * @start_blk: start block offset (in) + * @blkoff: start offset of the found extent (out) + * + * This function searches an extent of buffers marked "delayed" which + * starts from a block offset equal to or larger than @start_blk. If + * such an extent was found, this will store the start offset in + * @blkoff and return its length in blocks. Otherwise, zero is + * returned. + */ +unsigned long nilfs_find_uncommitted_extent(struct inode *inode, + sector_t start_blk, + sector_t *blkoff) +{ + unsigned int i; + pgoff_t index; + unsigned int nblocks_in_page; + unsigned long length = 0; + sector_t b; + struct pagevec pvec; + struct page *page; + + if (inode->i_mapping->nrpages == 0) + return 0; + + index = start_blk >> (PAGE_CACHE_SHIFT - inode->i_blkbits); + nblocks_in_page = 1U << (PAGE_CACHE_SHIFT - inode->i_blkbits); + + pagevec_init(&pvec, 0); + +repeat: + pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE, + pvec.pages); + if (pvec.nr == 0) + return length; + + if (length > 0 && pvec.pages[0]->index > index) + goto out; + + b = pvec.pages[0]->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + i = 0; + do { + page = pvec.pages[i]; + + lock_page(page); + if (page_has_buffers(page)) { + struct buffer_head *bh, *head; + + bh = head = page_buffers(page); + do { + if (b < start_blk) + continue; + if (buffer_delay(bh)) { + if (length == 0) + *blkoff = b; + length++; + } else if (length > 0) { + goto out_locked; + } + } while (++b, bh = bh->b_this_page, bh != head); + } else { + if (length > 0) + goto out_locked; + + b += nblocks_in_page; + } + unlock_page(page); + + } while (++i < pagevec_count(&pvec)); + + index = page->index + 1; + pagevec_release(&pvec); + cond_resched(); + goto repeat; + +out_locked: + unlock_page(page); +out: + pagevec_release(&pvec); + return length; +} -- cgit 1.2.3-korg