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 unp_t 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 (sb, "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) || Page_Uptodate(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)
126 ** the page is still kmapped (by whoever called reiserfs_get_block)
129 unsigned pgoff = (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
130 memset(page_address(unbh->b_page) + pgoff, 0, n_blk_size - total_tail) ;
133 inode->u.reiserfs_i.i_first_direct_byte = U32_MAX;
135 reiserfs_update_tail_transaction(inode);
140 /* stolen from fs/buffer.c */
141 void reiserfs_unmap_buffer(struct buffer_head *bh) {
142 if (buffer_mapped(bh)) {
143 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) {
146 mark_buffer_clean(bh) ;
148 clear_bit(BH_Mapped, &bh->b_state) ;
149 clear_bit(BH_Req, &bh->b_state) ;
150 clear_bit(BH_New, &bh->b_state) ;
156 unmap_buffers(struct page *page, loff_t pos) {
157 struct buffer_head *bh ;
158 struct buffer_head *head ;
159 struct buffer_head *next ;
160 unsigned long tail_index ;
161 unsigned long cur_index ;
165 tail_index = pos & (PAGE_CACHE_SIZE - 1) ;
167 head = page->buffers ;
170 next = bh->b_this_page ;
172 /* we want to unmap the buffers that contain the tail, and
173 ** all the buffers after it (since the tail must be at the
174 ** end of the file). We don't want to unmap file data
175 ** before the tail, since it might be dirty and waiting to
178 cur_index += bh->b_size ;
179 if (cur_index > tail_index) {
180 reiserfs_unmap_buffer(bh) ;
183 } while (bh != head) ;
188 /* this first locks inode (neither reads nor sync are permitted),
189 reads tail through page cache, insert direct item. When direct item
190 inserted successfully inode is left locked. Return value is always
191 what we expect from it (number of cut bytes). But when tail remains
192 in the unformatted node, we set mode to SKIP_BALANCING and unlock
194 int indirect2direct (struct reiserfs_transaction_handle *th,
195 struct inode * p_s_inode,
197 struct path * p_s_path, /* path to the indirect item. */
198 const struct cpu_key * p_s_item_key, /* Key to look for unformatted node pointer to be cut. */
199 loff_t n_new_file_size, /* New file size. */
202 struct super_block * p_s_sb = p_s_inode->i_sb;
203 struct item_head s_ih;
204 unsigned long n_block_size = p_s_sb->s_blocksize;
206 int tail_len, round_tail_len;
207 loff_t pos, pos1; /* position of first byte of the tail */
210 p_s_sb->u.reiserfs_sb.s_indirect2direct ++;
212 *p_c_mode = M_SKIP_BALANCING;
214 /* store item head path points to. */
215 copy_item_head (&s_ih, PATH_PITEM_HEAD(p_s_path));
217 tail_len = (n_new_file_size & (n_block_size - 1));
218 if (get_inode_sd_version (p_s_inode) == STAT_DATA_V2)
219 round_tail_len = ROUND_UP (tail_len);
221 round_tail_len = tail_len;
223 pos = le_ih_k_offset (&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
226 // we are protected by i_sem. The tail can not disapper, not
227 // append can be done either
228 // we are in truncate or packing tail in file_release
230 tail = (char *)kmap(page) ; /* this can schedule */
232 if (path_changed (&s_ih, p_s_path)) {
233 /* re-search indirect item */
234 if ( search_for_position_by_key (p_s_sb, p_s_item_key, p_s_path) == POSITION_NOT_FOUND )
235 reiserfs_panic(p_s_sb, "PAP-5520: indirect2direct: "
236 "item to be converted %K does not exist", p_s_item_key);
237 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path));
238 #ifdef CONFIG_REISERFS_CHECK
239 pos = le_ih_k_offset (&s_ih) - 1 +
240 (ih_item_len(&s_ih) / UNFM_P_SIZE - 1) * p_s_sb->s_blocksize;
242 reiserfs_panic (p_s_sb, "vs-5530: indirect2direct: "
243 "tail position changed while we were reading it");
248 /* Set direct item header to insert. */
249 make_le_item_head (&s_ih, 0, get_inode_item_key_version (p_s_inode), pos1 + 1,
250 TYPE_DIRECT, round_tail_len, 0xffff/*ih_free_space*/);
252 /* we want a pointer to the first byte of the tail in the page.
253 ** the page was locked and this part of the page was up to date when
254 ** indirect2direct was called, so we know the bytes are still valid
256 tail = tail + (pos & (PAGE_CACHE_SIZE - 1)) ;
258 PATH_LAST_POSITION(p_s_path)++;
261 set_cpu_key_k_type (&key, TYPE_DIRECT);
263 /* Insert tail as new direct item in the tree */
264 if ( reiserfs_insert_item(th, p_s_path, &key, &s_ih,
265 tail ? tail : NULL) < 0 ) {
266 /* No disk memory. So we can not convert last unformatted node
267 to the direct item. In this case we used to adjust
268 indirect items's ih_free_space. Now ih_free_space is not
269 used, it would be ideal to write zeros to corresponding
270 unformatted node. For now i_size is considered as guard for
271 going out of file size */
273 return n_block_size - round_tail_len;
277 /* this will invalidate all the buffers in the page after
280 unmap_buffers(page, pos1) ;
282 // note: we have now the same as in above direct2indirect
283 // conversion: there are two keys which have matching first three
284 // key components. They only differ by the fouhth one.
286 /* We have inserted new direct item and must remove last
288 p_s_inode->i_blocks += (p_s_sb->s_blocksize / 512);
291 /* we store position of first direct item in the in-core inode */
292 //mark_file_with_tail (p_s_inode, pos1 + 1);
293 p_s_inode->u.reiserfs_i.i_first_direct_byte = pos1 + 1;
295 return n_block_size - round_tail_len;