| /* |
| * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details |
| */ |
| |
| #include <linux/time.h> |
| #include <linux/pagemap.h> |
| #include <linux/buffer_head.h> |
| #include "reiserfs.h" |
| |
| /* access to tail : when one is going to read tail it must make sure, that is not running. |
| direct2indirect and indirect2direct can not run concurrently */ |
| |
| /* Converts direct items to an unformatted node. Panics if file has no |
| tail. -ENOSPC if no disk space for conversion */ |
| /* path points to first direct item of the file regarless of how many of |
| them are there */ |
| int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, |
| struct treepath *path, struct buffer_head *unbh, |
| loff_t tail_offset) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct buffer_head *up_to_date_bh; |
| struct item_head *p_le_ih = PATH_PITEM_HEAD(path); |
| unsigned long total_tail = 0; |
| struct cpu_key end_key; /* Key to search for the last byte of the |
| converted item. */ |
| struct item_head ind_ih; /* new indirect item to be inserted or |
| key of unfm pointer to be pasted */ |
| int blk_size, retval; /* returned value for reiserfs_insert_item and clones */ |
| unp_t unfm_ptr; /* Handle on an unformatted node |
| that will be inserted in the |
| tree. */ |
| |
| BUG_ON(!th->t_trans_id); |
| |
| REISERFS_SB(sb)->s_direct2indirect++; |
| |
| blk_size = sb->s_blocksize; |
| |
| /* and key to search for append or insert pointer to the new |
| unformatted node. */ |
| copy_item_head(&ind_ih, p_le_ih); |
| set_le_ih_k_offset(&ind_ih, tail_offset); |
| set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); |
| |
| /* Set the key to search for the place for new unfm pointer */ |
| make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); |
| |
| /* FIXME: we could avoid this */ |
| if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { |
| reiserfs_error(sb, "PAP-14030", |
| "pasted or inserted byte exists in " |
| "the tree %K. Use fsck to repair.", &end_key); |
| pathrelse(path); |
| return -EIO; |
| } |
| |
| p_le_ih = PATH_PITEM_HEAD(path); |
| |
| unfm_ptr = cpu_to_le32(unbh->b_blocknr); |
| |
| if (is_statdata_le_ih(p_le_ih)) { |
| /* Insert new indirect item. */ |
| set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ |
| put_ih_item_len(&ind_ih, UNFM_P_SIZE); |
| PATH_LAST_POSITION(path)++; |
| retval = |
| reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, |
| (char *)&unfm_ptr); |
| } else { |
| /* Paste into last indirect item of an object. */ |
| retval = reiserfs_paste_into_item(th, path, &end_key, inode, |
| (char *)&unfm_ptr, |
| UNFM_P_SIZE); |
| } |
| if (retval) { |
| return retval; |
| } |
| // note: from here there are two keys which have matching first |
| // three key components. They only differ by the fourth one. |
| |
| /* Set the key to search for the direct items of the file */ |
| make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, |
| 4); |
| |
| /* Move bytes from the direct items to the new unformatted node |
| and delete them. */ |
| while (1) { |
| int tail_size; |
| |
| /* end_key.k_offset is set so, that we will always have found |
| last item of the file */ |
| if (search_for_position_by_key(sb, &end_key, path) == |
| POSITION_FOUND) |
| reiserfs_panic(sb, "PAP-14050", |
| "direct item (%K) not found", &end_key); |
| p_le_ih = PATH_PITEM_HEAD(path); |
| RFALSE(!is_direct_le_ih(p_le_ih), |
| "vs-14055: direct item expected(%K), found %h", |
| &end_key, p_le_ih); |
| tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1)) |
| + ih_item_len(p_le_ih) - 1; |
| |
| /* we only send the unbh pointer if the buffer is not up to date. |
| ** this avoids overwriting good data from writepage() with old data |
| ** from the disk or buffer cache |
| ** Special case: unbh->b_page will be NULL if we are coming through |
| ** DIRECT_IO handler here. |
| */ |
| if (!unbh->b_page || buffer_uptodate(unbh) |
| || PageUptodate(unbh->b_page)) { |
| up_to_date_bh = NULL; |
| } else { |
| up_to_date_bh = unbh; |
| } |
| retval = reiserfs_delete_item(th, path, &end_key, inode, |
| up_to_date_bh); |
| |
| total_tail += retval; |
| if (tail_size == retval) |
| // done: file does not have direct items anymore |
| break; |
| |
| } |
| /* if we've copied bytes from disk into the page, we need to zero |
| ** out the unused part of the block (it was not up to date before) |
| */ |
| if (up_to_date_bh) { |
| unsigned pgoff = |
| (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1); |
| char *kaddr = kmap_atomic(up_to_date_bh->b_page, KM_USER0); |
| memset(kaddr + pgoff, 0, blk_size - total_tail); |
| kunmap_atomic(kaddr, KM_USER0); |
| } |
| |
| REISERFS_I(inode)->i_first_direct_byte = U32_MAX; |
| |
| return 0; |
| } |
| |
| /* stolen from fs/buffer.c */ |
| void reiserfs_unmap_buffer(struct buffer_head *bh) |
| { |
| lock_buffer(bh); |
| if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { |
| BUG(); |
| } |
| clear_buffer_dirty(bh); |
| /* Remove the buffer from whatever list it belongs to. We are mostly |
| interested in removing it from per-sb j_dirty_buffers list, to avoid |
| BUG() on attempt to write not mapped buffer */ |
| if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { |
| struct inode *inode = bh->b_page->mapping->host; |
| struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); |
| spin_lock(&j->j_dirty_buffers_lock); |
| list_del_init(&bh->b_assoc_buffers); |
| reiserfs_free_jh(bh); |
| spin_unlock(&j->j_dirty_buffers_lock); |
| } |
| clear_buffer_mapped(bh); |
| clear_buffer_req(bh); |
| clear_buffer_new(bh); |
| bh->b_bdev = NULL; |
| unlock_buffer(bh); |
| } |
| |
| /* this first locks inode (neither reads nor sync are permitted), |
| reads tail through page cache, insert direct item. When direct item |
| inserted successfully inode is left locked. Return value is always |
| what we expect from it (number of cut bytes). But when tail remains |
| in the unformatted node, we set mode to SKIP_BALANCING and unlock |
| inode */ |
| int indirect2direct(struct reiserfs_transaction_handle *th, |
| struct inode *inode, struct page *page, |
| struct treepath *path, /* path to the indirect item. */ |
| const struct cpu_key *item_key, /* Key to look for |
| * unformatted node |
| * pointer to be cut. */ |
| loff_t n_new_file_size, /* New file size. */ |
| char *mode) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct item_head s_ih; |
| unsigned long block_size = sb->s_blocksize; |
| char *tail; |
| int tail_len, round_tail_len; |
| loff_t pos, pos1; /* position of first byte of the tail */ |
| struct cpu_key key; |
| |
| BUG_ON(!th->t_trans_id); |
| |
| REISERFS_SB(sb)->s_indirect2direct++; |
| |
| *mode = M_SKIP_BALANCING; |
| |
| /* store item head path points to. */ |
| copy_item_head(&s_ih, PATH_PITEM_HEAD(path)); |
| |
| tail_len = (n_new_file_size & (block_size - 1)); |
| if (get_inode_sd_version(inode) == STAT_DATA_V2) |
| round_tail_len = ROUND_UP(tail_len); |
| else |
| round_tail_len = tail_len; |
| |
| pos = |
| le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - |
| 1) * sb->s_blocksize; |
| pos1 = pos; |
| |
| // we are protected by i_mutex. The tail can not disapper, not |
| // append can be done either |
| // we are in truncate or packing tail in file_release |
| |
| tail = (char *)kmap(page); /* this can schedule */ |
| |
| if (path_changed(&s_ih, path)) { |
| /* re-search indirect item */ |
| if (search_for_position_by_key(sb, item_key, path) |
| == POSITION_NOT_FOUND) |
| reiserfs_panic(sb, "PAP-5520", |
| "item to be converted %K does not exist", |
| item_key); |
| copy_item_head(&s_ih, PATH_PITEM_HEAD(path)); |
| #ifdef CONFIG_REISERFS_CHECK |
| pos = le_ih_k_offset(&s_ih) - 1 + |
| (ih_item_len(&s_ih) / UNFM_P_SIZE - |
| 1) * sb->s_blocksize; |
| if (pos != pos1) |
| reiserfs_panic(sb, "vs-5530", "tail position " |
| "changed while we were reading it"); |
| #endif |
| } |
| |
| /* Set direct item header to insert. */ |
| make_le_item_head(&s_ih, NULL, get_inode_item_key_version(inode), |
| pos1 + 1, TYPE_DIRECT, round_tail_len, |
| 0xffff /*ih_free_space */ ); |
| |
| /* we want a pointer to the first byte of the tail in the page. |
| ** the page was locked and this part of the page was up to date when |
| ** indirect2direct was called, so we know the bytes are still valid |
| */ |
| tail = tail + (pos & (PAGE_CACHE_SIZE - 1)); |
| |
| PATH_LAST_POSITION(path)++; |
| |
| key = *item_key; |
| set_cpu_key_k_type(&key, TYPE_DIRECT); |
| key.key_length = 4; |
| /* Insert tail as new direct item in the tree */ |
| if (reiserfs_insert_item(th, path, &key, &s_ih, inode, |
| tail ? tail : NULL) < 0) { |
| /* No disk memory. So we can not convert last unformatted node |
| to the direct item. In this case we used to adjust |
| indirect items's ih_free_space. Now ih_free_space is not |
| used, it would be ideal to write zeros to corresponding |
| unformatted node. For now i_size is considered as guard for |
| going out of file size */ |
| kunmap(page); |
| return block_size - round_tail_len; |
| } |
| kunmap(page); |
| |
| /* make sure to get the i_blocks changes from reiserfs_insert_item */ |
| reiserfs_update_sd(th, inode); |
| |
| // note: we have now the same as in above direct2indirect |
| // conversion: there are two keys which have matching first three |
| // key components. They only differ by the fouhth one. |
| |
| /* We have inserted new direct item and must remove last |
| unformatted node. */ |
| *mode = M_CUT; |
| |
| /* we store position of first direct item in the in-core inode */ |
| /* mark_file_with_tail (inode, pos1 + 1); */ |
| REISERFS_I(inode)->i_first_direct_byte = pos1 + 1; |
| |
| return block_size - round_tail_len; |
| } |