2 * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details
5 #include <linux/config.h>
6 #include <linux/time.h>
7 #include <linux/pagemap.h>
8 #include <linux/buffer_head.h>
9 #include <linux/reiserfs_fs.h>
11 /* access to tail : when one is going to read tail it must make sure, that is not running.
12 direct2indirect and indirect2direct can not run concurrently */
15 /* Converts direct items to an unformatted node. Panics if file has no
16 tail. -ENOSPC if no disk space for conversion */
17 /* path points to first direct item of the file regarless of how many of
19 int direct2indirect (struct reiserfs_transaction_handle *th, struct inode * inode,
20 struct path * path, struct buffer_head * unbh,
23 struct super_block * sb = inode->i_sb;
24 struct buffer_head *up_to_date_bh ;
25 struct item_head * p_le_ih = PATH_PITEM_HEAD (path);
26 unsigned long total_tail = 0 ;
27 struct cpu_key end_key; /* Key to search for the last byte of the
29 struct item_head ind_ih; /* new indirect item to be inserted or
30 key of unfm pointer to be pasted */
32 n_retval; /* returned value for reiserfs_insert_item and clones */
33 unp_t unfm_ptr; /* Handle on an unformatted node
34 that will be inserted in the
38 REISERFS_SB(sb)->s_direct2indirect ++;
40 n_blk_size = sb->s_blocksize;
42 /* and key to search for append or insert pointer to the new
44 copy_item_head (&ind_ih, p_le_ih);
45 set_le_ih_k_offset (&ind_ih, tail_offset);
46 set_le_ih_k_type (&ind_ih, TYPE_INDIRECT);
48 /* Set the key to search for the place for new unfm pointer */
49 make_cpu_key (&end_key, inode, tail_offset, TYPE_INDIRECT, 4);
51 // FIXME: we could avoid this
52 if ( search_for_position_by_key (sb, &end_key, path) == POSITION_FOUND ) {
53 reiserfs_warning ("PAP-14030: direct2indirect: "
54 "pasted or inserted byte exists in the tree %K. "
55 "Use fsck to repair.\n", &end_key);
60 p_le_ih = PATH_PITEM_HEAD (path);
62 unfm_ptr = cpu_to_le32 (unbh->b_blocknr);
64 if ( is_statdata_le_ih (p_le_ih) ) {
65 /* Insert new indirect item. */
66 set_ih_free_space (&ind_ih, 0); /* delete at nearest future */
67 put_ih_item_len( &ind_ih, UNFM_P_SIZE );
68 PATH_LAST_POSITION (path)++;
69 n_retval = reiserfs_insert_item (th, path, &end_key, &ind_ih,
72 /* Paste into last indirect item of an object. */
73 n_retval = reiserfs_paste_into_item(th, path, &end_key,
74 (char *)&unfm_ptr, UNFM_P_SIZE);
80 // note: from here there are two keys which have matching first
81 // three key components. They only differ by the fourth one.
84 /* Set the key to search for the direct items of the file */
85 make_cpu_key (&end_key, inode, max_reiserfs_offset (inode), TYPE_DIRECT, 4);
87 /* Move bytes from the direct items to the new unformatted node
92 /* end_key.k_offset is set so, that we will always have found
93 last item of the file */
94 if ( search_for_position_by_key (sb, &end_key, path) == POSITION_FOUND )
95 reiserfs_panic (sb, "PAP-14050: direct2indirect: "
96 "direct item (%K) not found", &end_key);
97 p_le_ih = PATH_PITEM_HEAD (path);
98 RFALSE( !is_direct_le_ih (p_le_ih),
99 "vs-14055: direct item expected(%K), found %h",
101 tail_size = (le_ih_k_offset (p_le_ih) & (n_blk_size - 1))
102 + ih_item_len(p_le_ih) - 1;
104 /* we only send the unbh pointer if the buffer is not up to date.
105 ** this avoids overwriting good data from writepage() with old data
106 ** from the disk or buffer cache
107 ** Special case: unbh->b_page will be NULL if we are coming through
108 ** DIRECT_IO handler here.
110 if (!unbh->b_page || buffer_uptodate(unbh) || PageUptodate(unbh->b_page)) {
111 up_to_date_bh = NULL ;
113 up_to_date_bh = unbh ;
115 n_retval = reiserfs_delete_item (th, path, &end_key, inode,
118 total_tail += n_retval ;
119 if (tail_size == n_retval)
120 // done: file does not have direct items anymore
124 /* if we've copied bytes from disk into the page, we need to zero
125 ** out the unused part of the block (it was not up to date before)
128 unsigned pgoff = (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
129 char *kaddr=kmap_atomic(up_to_date_bh->b_page, KM_USER0);
130 memset(kaddr + pgoff, 0, n_blk_size - total_tail) ;
131 kunmap_atomic(kaddr, KM_USER0);
134 REISERFS_I(inode)->i_first_direct_byte = U32_MAX;
140 /* stolen from fs/buffer.c */
141 void reiserfs_unmap_buffer(struct buffer_head *bh) {
143 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) {
146 clear_buffer_dirty(bh) ;
147 /* Remove the buffer from whatever list it belongs to. We are mostly
148 interested in removing it from per-sb j_dirty_buffers list, to avoid
149 BUG() on attempt to write not mapped buffer */
150 if ( (!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) {
151 struct inode *inode = bh->b_page->mapping->host;
152 struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb);
153 spin_lock(&j->j_dirty_buffers_lock);
154 list_del_init(&bh->b_assoc_buffers);
155 reiserfs_free_jh(bh);
156 spin_unlock(&j->j_dirty_buffers_lock);
158 clear_buffer_mapped(bh) ;
159 clear_buffer_req(bh) ;
160 clear_buffer_new(bh);
166 unmap_buffers(struct page *page, loff_t pos) {
167 struct buffer_head *bh ;
168 struct buffer_head *head ;
169 struct buffer_head *next ;
170 unsigned long tail_index ;
171 unsigned long cur_index ;
174 if (page_has_buffers(page)) {
175 tail_index = pos & (PAGE_CACHE_SIZE - 1) ;
177 head = page_buffers(page) ;
180 next = bh->b_this_page ;
182 /* we want to unmap the buffers that contain the tail, and
183 ** all the buffers after it (since the tail must be at the
184 ** end of the file). We don't want to unmap file data
185 ** before the tail, since it might be dirty and waiting to
188 cur_index += bh->b_size ;
189 if (cur_index > tail_index) {
190 reiserfs_unmap_buffer(bh) ;
193 } while (bh != head) ;
194 if ( PAGE_SIZE == bh->b_size ) {
195 clear_page_dirty(page);
201 /* this first locks inode (neither reads nor sync are permitted),
202 reads tail through page cache, insert direct item. When direct item
203 inserted successfully inode is left locked. Return value is always
204 what we expect from it (number of cut bytes). But when tail remains
205 in the unformatted node, we set mode to SKIP_BALANCING and unlock
207 int indirect2direct (struct reiserfs_transaction_handle *th,
208 struct inode * p_s_inode,
210 struct path * p_s_path, /* path to the indirect item. */
211 const struct cpu_key * p_s_item_key, /* Key to look for unformatted node pointer to be cut. */
212 loff_t n_new_file_size, /* New file size. */
215 struct super_block * p_s_sb = p_s_inode->i_sb;
216 struct item_head s_ih;
217 unsigned long n_block_size = p_s_sb->s_blocksize;
219 int tail_len, round_tail_len;
220 loff_t pos, pos1; /* position of first byte of the tail */
223 REISERFS_SB(p_s_sb)->s_indirect2direct ++;
225 *p_c_mode = M_SKIP_BALANCING;
227 /* store item head path points to. */
228 copy_item_head (&s_ih, PATH_PITEM_HEAD(p_s_path));
230 tail_len = (n_new_file_size & (n_block_size - 1));
231 if (get_inode_sd_version (p_s_inode) == STAT_DATA_V2)
232 round_tail_len = ROUND_UP (tail_len);
234 round_tail_len = tail_len;
236 pos = le_ih_k_offset (&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
239 // we are protected by i_sem. The tail can not disapper, not
240 // append can be done either
241 // we are in truncate or packing tail in file_release
243 tail = (char *)kmap(page) ; /* this can schedule */
245 if (path_changed (&s_ih, p_s_path)) {
246 /* re-search indirect item */
247 if ( search_for_position_by_key (p_s_sb, p_s_item_key, p_s_path) == POSITION_NOT_FOUND )
248 reiserfs_panic(p_s_sb, "PAP-5520: indirect2direct: "
249 "item to be converted %K does not exist", p_s_item_key);
250 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path));
251 #ifdef CONFIG_REISERFS_CHECK
252 pos = le_ih_k_offset (&s_ih) - 1 +
253 (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
255 reiserfs_panic (p_s_sb, "vs-5530: indirect2direct: "
256 "tail position changed while we were reading it");
261 /* Set direct item header to insert. */
262 make_le_item_head (&s_ih, 0, get_inode_item_key_version (p_s_inode), pos1 + 1,
263 TYPE_DIRECT, round_tail_len, 0xffff/*ih_free_space*/);
265 /* we want a pointer to the first byte of the tail in the page.
266 ** the page was locked and this part of the page was up to date when
267 ** indirect2direct was called, so we know the bytes are still valid
269 tail = tail + (pos & (PAGE_CACHE_SIZE - 1)) ;
271 PATH_LAST_POSITION(p_s_path)++;
274 set_cpu_key_k_type (&key, TYPE_DIRECT);
276 /* Insert tail as new direct item in the tree */
277 if ( reiserfs_insert_item(th, p_s_path, &key, &s_ih,
278 tail ? tail : NULL) < 0 ) {
279 /* No disk memory. So we can not convert last unformatted node
280 to the direct item. In this case we used to adjust
281 indirect items's ih_free_space. Now ih_free_space is not
282 used, it would be ideal to write zeros to corresponding
283 unformatted node. For now i_size is considered as guard for
284 going out of file size */
286 return n_block_size - round_tail_len;
290 /* this will invalidate all the buffers in the page after
293 unmap_buffers(page, pos1) ;
295 // note: we have now the same as in above direct2indirect
296 // conversion: there are two keys which have matching first three
297 // key components. They only differ by the fouhth one.
299 /* We have inserted new direct item and must remove last
301 p_s_inode->i_blocks += (p_s_sb->s_blocksize / 512);
304 /* we store position of first direct item in the in-core inode */
305 //mark_file_with_tail (p_s_inode, pos1 + 1);
306 REISERFS_I(p_s_inode)->i_first_direct_byte = pos1 + 1;
308 return n_block_size - round_tail_len;