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318 lines
9.2 KiB
318 lines
9.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright |
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* details |
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*/ |
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#include <linux/time.h> |
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#include <linux/pagemap.h> |
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#include <linux/buffer_head.h> |
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#include "reiserfs.h" |
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/* |
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* access to tail : when one is going to read tail it must make sure, that is |
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* not running. direct2indirect and indirect2direct can not run concurrently |
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*/ |
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/* |
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* Converts direct items to an unformatted node. Panics if file has no |
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* tail. -ENOSPC if no disk space for conversion |
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*/ |
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/* |
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* path points to first direct item of the file regardless of how many of |
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* them are there |
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*/ |
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int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, |
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struct treepath *path, struct buffer_head *unbh, |
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loff_t tail_offset) |
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{ |
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struct super_block *sb = inode->i_sb; |
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struct buffer_head *up_to_date_bh; |
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struct item_head *p_le_ih = tp_item_head(path); |
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unsigned long total_tail = 0; |
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/* Key to search for the last byte of the converted item. */ |
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struct cpu_key end_key; |
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/* |
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* new indirect item to be inserted or key |
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* of unfm pointer to be pasted |
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*/ |
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struct item_head ind_ih; |
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int blk_size; |
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/* returned value for reiserfs_insert_item and clones */ |
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int retval; |
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/* Handle on an unformatted node that will be inserted in the tree. */ |
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unp_t unfm_ptr; |
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BUG_ON(!th->t_trans_id); |
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REISERFS_SB(sb)->s_direct2indirect++; |
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blk_size = sb->s_blocksize; |
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/* |
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* and key to search for append or insert pointer to the new |
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* unformatted node. |
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*/ |
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copy_item_head(&ind_ih, p_le_ih); |
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set_le_ih_k_offset(&ind_ih, tail_offset); |
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set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); |
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/* Set the key to search for the place for new unfm pointer */ |
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make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); |
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/* FIXME: we could avoid this */ |
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if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { |
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reiserfs_error(sb, "PAP-14030", |
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"pasted or inserted byte exists in " |
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"the tree %K. Use fsck to repair.", &end_key); |
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pathrelse(path); |
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return -EIO; |
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} |
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p_le_ih = tp_item_head(path); |
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unfm_ptr = cpu_to_le32(unbh->b_blocknr); |
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if (is_statdata_le_ih(p_le_ih)) { |
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/* Insert new indirect item. */ |
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set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ |
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put_ih_item_len(&ind_ih, UNFM_P_SIZE); |
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PATH_LAST_POSITION(path)++; |
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retval = |
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reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, |
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(char *)&unfm_ptr); |
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} else { |
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/* Paste into last indirect item of an object. */ |
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retval = reiserfs_paste_into_item(th, path, &end_key, inode, |
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(char *)&unfm_ptr, |
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UNFM_P_SIZE); |
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} |
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if (retval) { |
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return retval; |
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} |
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/* |
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* note: from here there are two keys which have matching first |
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* three key components. They only differ by the fourth one. |
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*/ |
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/* Set the key to search for the direct items of the file */ |
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make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, |
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4); |
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/* |
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* Move bytes from the direct items to the new unformatted node |
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* and delete them. |
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*/ |
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while (1) { |
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int tail_size; |
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/* |
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* end_key.k_offset is set so, that we will always have found |
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* last item of the file |
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*/ |
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if (search_for_position_by_key(sb, &end_key, path) == |
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POSITION_FOUND) |
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reiserfs_panic(sb, "PAP-14050", |
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"direct item (%K) not found", &end_key); |
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p_le_ih = tp_item_head(path); |
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RFALSE(!is_direct_le_ih(p_le_ih), |
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"vs-14055: direct item expected(%K), found %h", |
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&end_key, p_le_ih); |
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tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1)) |
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+ ih_item_len(p_le_ih) - 1; |
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/* |
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* we only send the unbh pointer if the buffer is not |
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* up to date. this avoids overwriting good data from |
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* writepage() with old data from the disk or buffer cache |
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* Special case: unbh->b_page will be NULL if we are coming |
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* through DIRECT_IO handler here. |
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*/ |
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if (!unbh->b_page || buffer_uptodate(unbh) |
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|| PageUptodate(unbh->b_page)) { |
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up_to_date_bh = NULL; |
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} else { |
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up_to_date_bh = unbh; |
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} |
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retval = reiserfs_delete_item(th, path, &end_key, inode, |
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up_to_date_bh); |
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total_tail += retval; |
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/* done: file does not have direct items anymore */ |
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if (tail_size == retval) |
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break; |
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} |
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/* |
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* if we've copied bytes from disk into the page, we need to zero |
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* out the unused part of the block (it was not up to date before) |
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*/ |
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if (up_to_date_bh) { |
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unsigned pgoff = |
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(tail_offset + total_tail - 1) & (PAGE_SIZE - 1); |
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char *kaddr = kmap_atomic(up_to_date_bh->b_page); |
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memset(kaddr + pgoff, 0, blk_size - total_tail); |
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kunmap_atomic(kaddr); |
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} |
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REISERFS_I(inode)->i_first_direct_byte = U32_MAX; |
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return 0; |
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} |
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/* stolen from fs/buffer.c */ |
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void reiserfs_unmap_buffer(struct buffer_head *bh) |
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{ |
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lock_buffer(bh); |
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if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { |
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BUG(); |
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} |
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clear_buffer_dirty(bh); |
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/* |
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* Remove the buffer from whatever list it belongs to. We are mostly |
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* interested in removing it from per-sb j_dirty_buffers list, to avoid |
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* BUG() on attempt to write not mapped buffer |
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*/ |
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if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { |
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struct inode *inode = bh->b_page->mapping->host; |
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struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); |
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spin_lock(&j->j_dirty_buffers_lock); |
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list_del_init(&bh->b_assoc_buffers); |
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reiserfs_free_jh(bh); |
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spin_unlock(&j->j_dirty_buffers_lock); |
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} |
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clear_buffer_mapped(bh); |
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clear_buffer_req(bh); |
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clear_buffer_new(bh); |
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bh->b_bdev = NULL; |
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unlock_buffer(bh); |
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} |
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/* |
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* this first locks inode (neither reads nor sync are permitted), |
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* reads tail through page cache, insert direct item. When direct item |
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* inserted successfully inode is left locked. Return value is always |
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* what we expect from it (number of cut bytes). But when tail remains |
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* in the unformatted node, we set mode to SKIP_BALANCING and unlock |
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* inode |
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*/ |
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int indirect2direct(struct reiserfs_transaction_handle *th, |
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struct inode *inode, struct page *page, |
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struct treepath *path, /* path to the indirect item. */ |
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const struct cpu_key *item_key, /* Key to look for |
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* unformatted node |
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* pointer to be cut. */ |
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loff_t n_new_file_size, /* New file size. */ |
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char *mode) |
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{ |
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struct super_block *sb = inode->i_sb; |
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struct item_head s_ih; |
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unsigned long block_size = sb->s_blocksize; |
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char *tail; |
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int tail_len, round_tail_len; |
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loff_t pos, pos1; /* position of first byte of the tail */ |
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struct cpu_key key; |
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BUG_ON(!th->t_trans_id); |
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REISERFS_SB(sb)->s_indirect2direct++; |
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*mode = M_SKIP_BALANCING; |
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/* store item head path points to. */ |
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copy_item_head(&s_ih, tp_item_head(path)); |
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tail_len = (n_new_file_size & (block_size - 1)); |
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if (get_inode_sd_version(inode) == STAT_DATA_V2) |
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round_tail_len = ROUND_UP(tail_len); |
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else |
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round_tail_len = tail_len; |
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pos = |
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le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - |
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1) * sb->s_blocksize; |
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pos1 = pos; |
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/* |
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* we are protected by i_mutex. The tail can not disapper, not |
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* append can be done either |
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* we are in truncate or packing tail in file_release |
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*/ |
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tail = (char *)kmap(page); /* this can schedule */ |
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if (path_changed(&s_ih, path)) { |
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/* re-search indirect item */ |
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if (search_for_position_by_key(sb, item_key, path) |
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== POSITION_NOT_FOUND) |
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reiserfs_panic(sb, "PAP-5520", |
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"item to be converted %K does not exist", |
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item_key); |
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copy_item_head(&s_ih, tp_item_head(path)); |
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#ifdef CONFIG_REISERFS_CHECK |
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pos = le_ih_k_offset(&s_ih) - 1 + |
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(ih_item_len(&s_ih) / UNFM_P_SIZE - |
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1) * sb->s_blocksize; |
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if (pos != pos1) |
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reiserfs_panic(sb, "vs-5530", "tail position " |
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"changed while we were reading it"); |
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#endif |
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} |
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/* Set direct item header to insert. */ |
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make_le_item_head(&s_ih, NULL, get_inode_item_key_version(inode), |
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pos1 + 1, TYPE_DIRECT, round_tail_len, |
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0xffff /*ih_free_space */ ); |
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/* |
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* we want a pointer to the first byte of the tail in the page. |
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* the page was locked and this part of the page was up to date when |
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* indirect2direct was called, so we know the bytes are still valid |
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*/ |
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tail = tail + (pos & (PAGE_SIZE - 1)); |
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PATH_LAST_POSITION(path)++; |
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key = *item_key; |
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set_cpu_key_k_type(&key, TYPE_DIRECT); |
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key.key_length = 4; |
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/* Insert tail as new direct item in the tree */ |
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if (reiserfs_insert_item(th, path, &key, &s_ih, inode, |
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tail ? tail : NULL) < 0) { |
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/* |
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* No disk memory. So we can not convert last unformatted node |
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* to the direct item. In this case we used to adjust |
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* indirect items's ih_free_space. Now ih_free_space is not |
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* used, it would be ideal to write zeros to corresponding |
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* unformatted node. For now i_size is considered as guard for |
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* going out of file size |
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*/ |
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kunmap(page); |
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return block_size - round_tail_len; |
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} |
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kunmap(page); |
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/* make sure to get the i_blocks changes from reiserfs_insert_item */ |
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reiserfs_update_sd(th, inode); |
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/* |
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* note: we have now the same as in above direct2indirect |
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* conversion: there are two keys which have matching first three |
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* key components. They only differ by the fourth one. |
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*/ |
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/* |
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* We have inserted new direct item and must remove last |
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* unformatted node. |
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*/ |
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*mode = M_CUT; |
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/* we store position of first direct item in the in-core inode */ |
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/* mark_file_with_tail (inode, pos1 + 1); */ |
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REISERFS_I(inode)->i_first_direct_byte = pos1 + 1; |
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return block_size - round_tail_len; |
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}
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