2 * Copyright 1999-2002 Hans Reiser, see reiserfs/README for licensing and copyright details
5 #include <linux/config.h>
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/reiserfs_fs.h>
9 #include <linux/locks.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 struct unfm_nodeinfo unfm_ptr; /* Handle on an unformatted node
34 that will be inserted in the
38 sb->u.reiserfs_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.unfm_nodenum = cpu_to_le32 (unbh->b_blocknr);
63 unfm_ptr.unfm_freespace = 0; // ???
65 if ( is_statdata_le_ih (p_le_ih) ) {
66 /* Insert new indirect item. */
67 set_ih_free_space (&ind_ih, 0); /* delete at nearest future */
68 put_ih_item_len( &ind_ih, UNFM_P_SIZE );
69 PATH_LAST_POSITION (path)++;
70 n_retval = reiserfs_insert_item (th, path, &end_key, &ind_ih,
73 /* Paste into last indirect item of an object. */
74 n_retval = reiserfs_paste_into_item(th, path, &end_key,
75 (char *)&unfm_ptr, UNFM_P_SIZE);
81 // note: from here there are two keys which have matching first
82 // three key components. They only differ by the fourth one.
85 /* Set the key to search for the direct items of the file */
86 make_cpu_key (&end_key, inode, max_reiserfs_offset (inode), TYPE_DIRECT, 4);
88 /* Move bytes from the direct items to the new unformatted node
93 /* end_key.k_offset is set so, that we will always have found
94 last item of the file */
95 if ( search_for_position_by_key (sb, &end_key, path) == POSITION_FOUND )
96 reiserfs_panic (sb, "PAP-14050: direct2indirect: "
97 "direct item (%K) not found", &end_key);
98 p_le_ih = PATH_PITEM_HEAD (path);
99 RFALSE( !is_direct_le_ih (p_le_ih),
100 "vs-14055: direct item expected(%K), found %h",
102 tail_size = (le_ih_k_offset (p_le_ih) & (n_blk_size - 1))
103 + ih_item_len(p_le_ih) - 1;
105 /* we only send the unbh pointer if the buffer is not up to date.
106 ** this avoids overwriting good data from writepage() with old data
107 ** from the disk or buffer cache
109 if (buffer_uptodate(unbh) || Page_Uptodate(unbh->b_page)) {
110 up_to_date_bh = NULL ;
112 up_to_date_bh = unbh ;
114 n_retval = reiserfs_delete_item (th, path, &end_key, inode,
117 total_tail += n_retval ;
118 if (tail_size == n_retval)
119 // done: file does not have direct items anymore
123 /* if we've copied bytes from disk into the page, we need to zero
124 ** out the unused part of the block (it was not up to date before)
125 ** the page is still kmapped (by whoever called reiserfs_get_block)
128 unsigned pgoff = (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
129 memset(page_address(unbh->b_page) + pgoff, 0, n_blk_size - total_tail) ;
132 inode->u.reiserfs_i.i_first_direct_byte = U32_MAX;
138 /* stolen from fs/buffer.c */
139 void reiserfs_unmap_buffer(struct buffer_head *bh) {
140 if (buffer_mapped(bh)) {
141 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) {
144 mark_buffer_clean(bh) ;
146 clear_bit(BH_Mapped, &bh->b_state) ;
147 clear_bit(BH_Req, &bh->b_state) ;
148 clear_bit(BH_New, &bh->b_state) ;
154 unmap_buffers(struct page *page, loff_t pos) {
155 struct buffer_head *bh ;
156 struct buffer_head *head ;
157 struct buffer_head *next ;
158 unsigned long tail_index ;
159 unsigned long cur_index ;
163 tail_index = pos & (PAGE_CACHE_SIZE - 1) ;
165 head = page->buffers ;
168 next = bh->b_this_page ;
170 /* we want to unmap the buffers that contain the tail, and
171 ** all the buffers after it (since the tail must be at the
172 ** end of the file). We don't want to unmap file data
173 ** before the tail, since it might be dirty and waiting to
176 cur_index += bh->b_size ;
177 if (cur_index > tail_index) {
178 reiserfs_unmap_buffer(bh) ;
181 } while (bh != head) ;
186 /* this first locks inode (neither reads nor sync are permitted),
187 reads tail through page cache, insert direct item. When direct item
188 inserted successfully inode is left locked. Return value is always
189 what we expect from it (number of cut bytes). But when tail remains
190 in the unformatted node, we set mode to SKIP_BALANCING and unlock
192 int indirect2direct (struct reiserfs_transaction_handle *th,
193 struct inode * p_s_inode,
195 struct path * p_s_path, /* path to the indirect item. */
196 const struct cpu_key * p_s_item_key, /* Key to look for unformatted node pointer to be cut. */
197 loff_t n_new_file_size, /* New file size. */
200 struct super_block * p_s_sb = p_s_inode->i_sb;
201 struct item_head s_ih;
202 unsigned long n_block_size = p_s_sb->s_blocksize;
204 int tail_len, round_tail_len;
205 loff_t pos, pos1; /* position of first byte of the tail */
208 p_s_sb->u.reiserfs_sb.s_indirect2direct ++;
210 *p_c_mode = M_SKIP_BALANCING;
212 /* store item head path points to. */
213 copy_item_head (&s_ih, PATH_PITEM_HEAD(p_s_path));
215 tail_len = (n_new_file_size & (n_block_size - 1));
216 if (get_inode_sd_version (p_s_inode) == STAT_DATA_V2)
217 round_tail_len = ROUND_UP (tail_len);
219 round_tail_len = tail_len;
221 pos = le_ih_k_offset (&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
224 // we are protected by i_sem. The tail can not disapper, not
225 // append can be done either
226 // we are in truncate or packing tail in file_release
228 tail = (char *)kmap(page) ; /* this can schedule */
230 if (path_changed (&s_ih, p_s_path)) {
231 /* re-search indirect item */
232 if ( search_for_position_by_key (p_s_sb, p_s_item_key, p_s_path) == POSITION_NOT_FOUND )
233 reiserfs_panic(p_s_sb, "PAP-5520: indirect2direct: "
234 "item to be converted %K does not exist", p_s_item_key);
235 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path));
236 #ifdef CONFIG_REISERFS_CHECK
237 pos = le_ih_k_offset (&s_ih) - 1 +
238 (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
240 reiserfs_panic (p_s_sb, "vs-5530: indirect2direct: "
241 "tail position changed while we were reading it");
246 /* Set direct item header to insert. */
247 make_le_item_head (&s_ih, 0, get_inode_item_key_version (p_s_inode), pos1 + 1,
248 TYPE_DIRECT, round_tail_len, 0xffff/*ih_free_space*/);
250 /* we want a pointer to the first byte of the tail in the page.
251 ** the page was locked and this part of the page was up to date when
252 ** indirect2direct was called, so we know the bytes are still valid
254 tail = tail + (pos & (PAGE_CACHE_SIZE - 1)) ;
256 PATH_LAST_POSITION(p_s_path)++;
259 set_cpu_key_k_type (&key, TYPE_DIRECT);
261 /* Insert tail as new direct item in the tree */
262 if ( reiserfs_insert_item(th, p_s_path, &key, &s_ih,
263 tail ? tail : NULL) < 0 ) {
264 /* No disk memory. So we can not convert last unformatted node
265 to the direct item. In this case we used to adjust
266 indirect items's ih_free_space. Now ih_free_space is not
267 used, it would be ideal to write zeros to corresponding
268 unformatted node. For now i_size is considered as guard for
269 going out of file size */
271 return n_block_size - round_tail_len;
275 /* this will invalidate all the buffers in the page after
278 unmap_buffers(page, pos1) ;
280 // note: we have now the same as in above direct2indirect
281 // conversion: there are two keys which have matching first three
282 // key components. They only differ by the fouhth one.
284 /* We have inserted new direct item and must remove last
286 p_s_inode->i_blocks += (p_s_sb->s_blocksize / 512);
289 /* we store position of first direct item in the in-core inode */
290 //mark_file_with_tail (p_s_inode, pos1 + 1);
291 p_s_inode->u.reiserfs_i.i_first_direct_byte = pos1 + 1;
293 return n_block_size - round_tail_len;