diff options
| -rw-r--r-- | fs/nilfs2/btnode.c | 316 | ||||
| -rw-r--r-- | fs/nilfs2/btnode.h | 58 |
2 files changed, 374 insertions, 0 deletions
diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c new file mode 100644 index 0000000..4cc07b2 --- /dev/null +++ b/fs/nilfs2/btnode.c @@ -0,0 +1,316 @@ +/* + * btnode.c - NILFS B-tree node cache + * + * 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 + * + * This file was originally written by Seiji Kihara <kihara@osrg.net> + * and fully revised by Ryusuke Konishi <ryusuke@osrg.net> for + * stabilization and simplification. + * + */ + +#include <linux/types.h> +#include <linux/buffer_head.h> +#include <linux/mm.h> +#include <linux/backing-dev.h> +#include "nilfs.h" +#include "mdt.h" +#include "dat.h" +#include "page.h" +#include "btnode.h" + + +void nilfs_btnode_cache_init_once(struct address_space *btnc) +{ + INIT_RADIX_TREE(&btnc->page_tree, GFP_ATOMIC); + spin_lock_init(&btnc->tree_lock); + INIT_LIST_HEAD(&btnc->private_list); + spin_lock_init(&btnc->private_lock); + + spin_lock_init(&btnc->i_mmap_lock); + INIT_RAW_PRIO_TREE_ROOT(&btnc->i_mmap); + INIT_LIST_HEAD(&btnc->i_mmap_nonlinear); +} + +static struct address_space_operations def_btnode_aops; + +void nilfs_btnode_cache_init(struct address_space *btnc) +{ + btnc->host = NULL; /* can safely set to host inode ? */ + btnc->flags = 0; + mapping_set_gfp_mask(btnc, GFP_NOFS); + btnc->assoc_mapping = NULL; + btnc->backing_dev_info = &default_backing_dev_info; + btnc->a_ops = &def_btnode_aops; +} + +void nilfs_btnode_cache_clear(struct address_space *btnc) +{ + invalidate_mapping_pages(btnc, 0, -1); + truncate_inode_pages(btnc, 0); +} + +int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, + sector_t pblocknr, struct buffer_head **pbh, + int newblk) +{ + struct buffer_head *bh; + struct inode *inode = NILFS_BTNC_I(btnc); + int err; + + bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node); + if (unlikely(!bh)) + return -ENOMEM; + + err = -EEXIST; /* internal code */ + if (newblk) { + if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || + buffer_dirty(bh))) { + brelse(bh); + BUG(); + } + bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; + bh->b_blocknr = blocknr; + set_buffer_mapped(bh); + set_buffer_uptodate(bh); + goto found; + } + + if (buffer_uptodate(bh) || buffer_dirty(bh)) + goto found; + + if (pblocknr == 0) { + pblocknr = blocknr; + if (inode->i_ino != NILFS_DAT_INO) { + struct inode *dat = + nilfs_dat_inode(NILFS_I_NILFS(inode)); + + /* blocknr is a virtual block number */ + err = nilfs_dat_translate(dat, blocknr, &pblocknr); + if (unlikely(err)) { + brelse(bh); + goto out_locked; + } + } + } + lock_buffer(bh); + if (buffer_uptodate(bh)) { + unlock_buffer(bh); + err = -EEXIST; /* internal code */ + goto found; + } + set_buffer_mapped(bh); + bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; + bh->b_blocknr = pblocknr; /* set block address for read */ + bh->b_end_io = end_buffer_read_sync; + get_bh(bh); + submit_bh(READ, bh); + bh->b_blocknr = blocknr; /* set back to the given block address */ + err = 0; +found: + *pbh = bh; + +out_locked: + unlock_page(bh->b_page); + page_cache_release(bh->b_page); + return err; +} + +int nilfs_btnode_get(struct address_space *btnc, __u64 blocknr, + sector_t pblocknr, struct buffer_head **pbh, int newblk) +{ + struct buffer_head *bh; + int err; + + err = nilfs_btnode_submit_block(btnc, blocknr, pblocknr, pbh, newblk); + if (err == -EEXIST) /* internal code (cache hit) */ + return 0; + if (unlikely(err)) + return err; + + bh = *pbh; + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) { + brelse(bh); + return -EIO; + } + return 0; +} + +/** + * nilfs_btnode_delete - delete B-tree node buffer + * @bh: buffer to be deleted + * + * nilfs_btnode_delete() invalidates the specified buffer and delete the page + * including the buffer if the page gets unbusy. + */ +void nilfs_btnode_delete(struct buffer_head *bh) +{ + struct address_space *mapping; + struct page *page = bh->b_page; + pgoff_t index = page_index(page); + int still_dirty; + + page_cache_get(page); + lock_page(page); + wait_on_page_writeback(page); + + nilfs_forget_buffer(bh); + still_dirty = PageDirty(page); + mapping = page->mapping; + unlock_page(page); + page_cache_release(page); + + if (!still_dirty && mapping) + invalidate_inode_pages2_range(mapping, index, index); +} + +/** + * nilfs_btnode_prepare_change_key + * prepare to move contents of the block for old key to one of new key. + * the old buffer will not be removed, but might be reused for new buffer. + * it might return -ENOMEM because of memory allocation errors, + * and might return -EIO because of disk read errors. + */ +int nilfs_btnode_prepare_change_key(struct address_space *btnc, + struct nilfs_btnode_chkey_ctxt *ctxt) +{ + struct buffer_head *obh, *nbh; + struct inode *inode = NILFS_BTNC_I(btnc); + __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; + int err; + + if (oldkey == newkey) + return 0; + + obh = ctxt->bh; + ctxt->newbh = NULL; + + if (inode->i_blkbits == PAGE_CACHE_SHIFT) { + lock_page(obh->b_page); + /* + * We cannot call radix_tree_preload for the kernels older + * than 2.6.23, because it is not exported for modules. + */ + err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); + if (err) + goto failed_unlock; + /* BUG_ON(oldkey != obh->b_page->index); */ + if (unlikely(oldkey != obh->b_page->index)) + NILFS_PAGE_BUG(obh->b_page, + "invalid oldkey %lld (newkey=%lld)", + (unsigned long long)oldkey, + (unsigned long long)newkey); + +retry: + spin_lock_irq(&btnc->tree_lock); + err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page); + spin_unlock_irq(&btnc->tree_lock); + /* + * Note: page->index will not change to newkey until + * nilfs_btnode_commit_change_key() will be called. + * To protect the page in intermediate state, the page lock + * is held. + */ + radix_tree_preload_end(); + if (!err) + return 0; + else if (err != -EEXIST) + goto failed_unlock; + + err = invalidate_inode_pages2_range(btnc, newkey, newkey); + if (!err) + goto retry; + /* fallback to copy mode */ + unlock_page(obh->b_page); + } + + err = nilfs_btnode_get(btnc, newkey, 0, &nbh, 1); + if (likely(!err)) { + BUG_ON(nbh == obh); + ctxt->newbh = nbh; + } + return err; + + failed_unlock: + unlock_page(obh->b_page); + return err; +} + +/** + * nilfs_btnode_commit_change_key + * commit the change_key operation prepared by prepare_change_key(). + */ +void nilfs_btnode_commit_change_key(struct address_space *btnc, + struct nilfs_btnode_chkey_ctxt *ctxt) +{ + struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh; + __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; + struct page *opage; + + if (oldkey == newkey) + return; + + if (nbh == NULL) { /* blocksize == pagesize */ + opage = obh->b_page; + if (unlikely(oldkey != opage->index)) + NILFS_PAGE_BUG(opage, + "invalid oldkey %lld (newkey=%lld)", + (unsigned long long)oldkey, + (unsigned long long)newkey); + if (!test_set_buffer_dirty(obh) && TestSetPageDirty(opage)) + BUG(); + + spin_lock_irq(&btnc->tree_lock); + radix_tree_delete(&btnc->page_tree, oldkey); + radix_tree_tag_set(&btnc->page_tree, newkey, + PAGECACHE_TAG_DIRTY); + spin_unlock_irq(&btnc->tree_lock); + + opage->index = obh->b_blocknr = newkey; + unlock_page(opage); + } else { + nilfs_copy_buffer(nbh, obh); + nilfs_btnode_mark_dirty(nbh); + + nbh->b_blocknr = newkey; + ctxt->bh = nbh; + nilfs_btnode_delete(obh); /* will decrement bh->b_count */ + } +} + +/** + * nilfs_btnode_abort_change_key + * abort the change_key operation prepared by prepare_change_key(). + */ +void nilfs_btnode_abort_change_key(struct address_space *btnc, + struct nilfs_btnode_chkey_ctxt *ctxt) +{ + struct buffer_head *nbh = ctxt->newbh; + __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; + + if (oldkey == newkey) + return; + + if (nbh == NULL) { /* blocksize == pagesize */ + spin_lock_irq(&btnc->tree_lock); + radix_tree_delete(&btnc->page_tree, newkey); + spin_unlock_irq(&btnc->tree_lock); + unlock_page(ctxt->bh->b_page); + } else + brelse(nbh); +} diff --git a/fs/nilfs2/btnode.h b/fs/nilfs2/btnode.h new file mode 100644 index 0000000..35faa86 --- /dev/null +++ b/fs/nilfs2/btnode.h @@ -0,0 +1,58 @@ +/* + * btnode.h - NILFS B-tree node cache + * + * 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 Seiji Kihara <kihara@osrg.net> + * Revised by Ryusuke Konishi <ryusuke@osrg.net> + */ + +#ifndef _NILFS_BTNODE_H +#define _NILFS_BTNODE_H + +#include <linux/types.h> +#include <linux/buffer_head.h> +#include <linux/fs.h> +#include <linux/backing-dev.h> + + +struct nilfs_btnode_chkey_ctxt { + __u64 oldkey; + __u64 newkey; + struct buffer_head *bh; + struct buffer_head *newbh; +}; + +void nilfs_btnode_cache_init_once(struct address_space *); +void nilfs_btnode_cache_init(struct address_space *); +void nilfs_btnode_cache_clear(struct address_space *); +int nilfs_btnode_submit_block(struct address_space *, __u64, sector_t, + struct buffer_head **, int); +int nilfs_btnode_get(struct address_space *, __u64, sector_t, + struct buffer_head **, int); +void nilfs_btnode_delete(struct buffer_head *); +int nilfs_btnode_prepare_change_key(struct address_space *, + struct nilfs_btnode_chkey_ctxt *); +void nilfs_btnode_commit_change_key(struct address_space *, + struct nilfs_btnode_chkey_ctxt *); +void nilfs_btnode_abort_change_key(struct address_space *, + struct nilfs_btnode_chkey_ctxt *); + +#define nilfs_btnode_mark_dirty(bh) nilfs_mark_buffer_dirty(bh) + + +#endif /* _NILFS_BTNODE_H */ |