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273 lines
6.6 KiB
273 lines
6.6 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* btnode.c - NILFS B-tree node cache |
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* |
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
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* |
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* Originally written by Seiji Kihara. |
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* Fully revised by Ryusuke Konishi for stabilization and simplification. |
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* |
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*/ |
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#include <linux/types.h> |
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#include <linux/buffer_head.h> |
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#include <linux/mm.h> |
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#include <linux/backing-dev.h> |
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#include <linux/gfp.h> |
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#include "nilfs.h" |
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#include "mdt.h" |
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#include "dat.h" |
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#include "page.h" |
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#include "btnode.h" |
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void nilfs_btnode_cache_clear(struct address_space *btnc) |
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{ |
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invalidate_mapping_pages(btnc, 0, -1); |
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truncate_inode_pages(btnc, 0); |
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} |
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struct buffer_head * |
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nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) |
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{ |
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struct inode *inode = NILFS_BTNC_I(btnc); |
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struct buffer_head *bh; |
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bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); |
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if (unlikely(!bh)) |
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return NULL; |
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if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || |
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buffer_dirty(bh))) { |
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brelse(bh); |
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BUG(); |
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} |
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memset(bh->b_data, 0, i_blocksize(inode)); |
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bh->b_bdev = inode->i_sb->s_bdev; |
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bh->b_blocknr = blocknr; |
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set_buffer_mapped(bh); |
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set_buffer_uptodate(bh); |
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unlock_page(bh->b_page); |
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put_page(bh->b_page); |
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return bh; |
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} |
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int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, |
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sector_t pblocknr, int mode, int mode_flags, |
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struct buffer_head **pbh, sector_t *submit_ptr) |
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{ |
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struct buffer_head *bh; |
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struct inode *inode = NILFS_BTNC_I(btnc); |
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struct page *page; |
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int err; |
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bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); |
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if (unlikely(!bh)) |
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return -ENOMEM; |
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err = -EEXIST; /* internal code */ |
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page = bh->b_page; |
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if (buffer_uptodate(bh) || buffer_dirty(bh)) |
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goto found; |
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if (pblocknr == 0) { |
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pblocknr = blocknr; |
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if (inode->i_ino != NILFS_DAT_INO) { |
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struct the_nilfs *nilfs = inode->i_sb->s_fs_info; |
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/* blocknr is a virtual block number */ |
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err = nilfs_dat_translate(nilfs->ns_dat, blocknr, |
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&pblocknr); |
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if (unlikely(err)) { |
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brelse(bh); |
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goto out_locked; |
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} |
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} |
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} |
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if (mode_flags & REQ_RAHEAD) { |
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if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) { |
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err = -EBUSY; /* internal code */ |
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brelse(bh); |
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goto out_locked; |
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} |
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} else { /* mode == READ */ |
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lock_buffer(bh); |
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} |
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if (buffer_uptodate(bh)) { |
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unlock_buffer(bh); |
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err = -EEXIST; /* internal code */ |
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goto found; |
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} |
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set_buffer_mapped(bh); |
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bh->b_bdev = inode->i_sb->s_bdev; |
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bh->b_blocknr = pblocknr; /* set block address for read */ |
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bh->b_end_io = end_buffer_read_sync; |
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get_bh(bh); |
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submit_bh(mode, mode_flags, bh); |
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bh->b_blocknr = blocknr; /* set back to the given block address */ |
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*submit_ptr = pblocknr; |
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err = 0; |
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found: |
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*pbh = bh; |
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out_locked: |
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unlock_page(page); |
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put_page(page); |
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return err; |
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} |
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/** |
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* nilfs_btnode_delete - delete B-tree node buffer |
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* @bh: buffer to be deleted |
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* |
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* nilfs_btnode_delete() invalidates the specified buffer and delete the page |
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* including the buffer if the page gets unbusy. |
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*/ |
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void nilfs_btnode_delete(struct buffer_head *bh) |
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{ |
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struct address_space *mapping; |
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struct page *page = bh->b_page; |
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pgoff_t index = page_index(page); |
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int still_dirty; |
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get_page(page); |
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lock_page(page); |
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wait_on_page_writeback(page); |
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nilfs_forget_buffer(bh); |
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still_dirty = PageDirty(page); |
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mapping = page->mapping; |
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unlock_page(page); |
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put_page(page); |
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if (!still_dirty && mapping) |
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invalidate_inode_pages2_range(mapping, index, index); |
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} |
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/** |
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* nilfs_btnode_prepare_change_key |
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* prepare to move contents of the block for old key to one of new key. |
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* the old buffer will not be removed, but might be reused for new buffer. |
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* it might return -ENOMEM because of memory allocation errors, |
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* and might return -EIO because of disk read errors. |
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*/ |
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int nilfs_btnode_prepare_change_key(struct address_space *btnc, |
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struct nilfs_btnode_chkey_ctxt *ctxt) |
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{ |
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struct buffer_head *obh, *nbh; |
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struct inode *inode = NILFS_BTNC_I(btnc); |
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__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
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int err; |
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if (oldkey == newkey) |
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return 0; |
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obh = ctxt->bh; |
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ctxt->newbh = NULL; |
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if (inode->i_blkbits == PAGE_SHIFT) { |
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struct page *opage = obh->b_page; |
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lock_page(opage); |
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retry: |
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/* BUG_ON(oldkey != obh->b_page->index); */ |
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if (unlikely(oldkey != opage->index)) |
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NILFS_PAGE_BUG(opage, |
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"invalid oldkey %lld (newkey=%lld)", |
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(unsigned long long)oldkey, |
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(unsigned long long)newkey); |
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xa_lock_irq(&btnc->i_pages); |
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err = __xa_insert(&btnc->i_pages, newkey, opage, GFP_NOFS); |
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xa_unlock_irq(&btnc->i_pages); |
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/* |
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* Note: page->index will not change to newkey until |
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* nilfs_btnode_commit_change_key() will be called. |
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* To protect the page in intermediate state, the page lock |
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* is held. |
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*/ |
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if (!err) |
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return 0; |
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else if (err != -EBUSY) |
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goto failed_unlock; |
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err = invalidate_inode_pages2_range(btnc, newkey, newkey); |
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if (!err) |
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goto retry; |
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/* fallback to copy mode */ |
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unlock_page(opage); |
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} |
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nbh = nilfs_btnode_create_block(btnc, newkey); |
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if (!nbh) |
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return -ENOMEM; |
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BUG_ON(nbh == obh); |
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ctxt->newbh = nbh; |
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return 0; |
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failed_unlock: |
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unlock_page(obh->b_page); |
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return err; |
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} |
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/** |
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* nilfs_btnode_commit_change_key |
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* commit the change_key operation prepared by prepare_change_key(). |
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*/ |
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void nilfs_btnode_commit_change_key(struct address_space *btnc, |
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struct nilfs_btnode_chkey_ctxt *ctxt) |
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{ |
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struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh; |
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__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
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struct page *opage; |
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if (oldkey == newkey) |
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return; |
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if (nbh == NULL) { /* blocksize == pagesize */ |
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opage = obh->b_page; |
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if (unlikely(oldkey != opage->index)) |
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NILFS_PAGE_BUG(opage, |
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"invalid oldkey %lld (newkey=%lld)", |
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(unsigned long long)oldkey, |
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(unsigned long long)newkey); |
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mark_buffer_dirty(obh); |
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xa_lock_irq(&btnc->i_pages); |
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__xa_erase(&btnc->i_pages, oldkey); |
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__xa_set_mark(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY); |
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xa_unlock_irq(&btnc->i_pages); |
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opage->index = obh->b_blocknr = newkey; |
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unlock_page(opage); |
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} else { |
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nilfs_copy_buffer(nbh, obh); |
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mark_buffer_dirty(nbh); |
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nbh->b_blocknr = newkey; |
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ctxt->bh = nbh; |
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nilfs_btnode_delete(obh); /* will decrement bh->b_count */ |
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} |
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} |
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/** |
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* nilfs_btnode_abort_change_key |
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* abort the change_key operation prepared by prepare_change_key(). |
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*/ |
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void nilfs_btnode_abort_change_key(struct address_space *btnc, |
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struct nilfs_btnode_chkey_ctxt *ctxt) |
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{ |
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struct buffer_head *nbh = ctxt->newbh; |
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__u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
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if (oldkey == newkey) |
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return; |
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if (nbh == NULL) { /* blocksize == pagesize */ |
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xa_erase_irq(&btnc->i_pages, newkey); |
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unlock_page(ctxt->bh->b_page); |
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} else |
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brelse(nbh); |
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}
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