1 /* 2 * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright 3 * details 4 */ 5 6 #include <linux/time.h> 7 #include <linux/pagemap.h> 8 #include <linux/buffer_head.h> 9 #include "reiserfs.h" 10 11 /* 12 * access to tail : when one is going to read tail it must make sure, that is 13 * not running. direct2indirect and indirect2direct can not run concurrently 14 */ 15 16 /* 17 * Converts direct items to an unformatted node. Panics if file has no 18 * tail. -ENOSPC if no disk space for conversion 19 */ 20 /* 21 * path points to first direct item of the file regardless of how many of 22 * them are there 23 */ 24 int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, 25 struct treepath *path, struct buffer_head *unbh, 26 loff_t tail_offset) 27 { 28 struct super_block *sb = inode->i_sb; 29 struct buffer_head *up_to_date_bh; 30 struct item_head *p_le_ih = tp_item_head(path); 31 unsigned long total_tail = 0; 32 33 /* Key to search for the last byte of the converted item. */ 34 struct cpu_key end_key; 35 36 /* 37 * new indirect item to be inserted or key 38 * of unfm pointer to be pasted 39 */ 40 struct item_head ind_ih; 41 int blk_size; 42 /* returned value for reiserfs_insert_item and clones */ 43 int retval; 44 /* Handle on an unformatted node that will be inserted in the tree. */ 45 unp_t unfm_ptr; 46 47 BUG_ON(!th->t_trans_id); 48 49 REISERFS_SB(sb)->s_direct2indirect++; 50 51 blk_size = sb->s_blocksize; 52 53 /* 54 * and key to search for append or insert pointer to the new 55 * unformatted node. 56 */ 57 copy_item_head(&ind_ih, p_le_ih); 58 set_le_ih_k_offset(&ind_ih, tail_offset); 59 set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); 60 61 /* Set the key to search for the place for new unfm pointer */ 62 make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); 63 64 /* FIXME: we could avoid this */ 65 if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { 66 reiserfs_error(sb, "PAP-14030", 67 "pasted or inserted byte exists in " 68 "the tree %K. Use fsck to repair.", &end_key); 69 pathrelse(path); 70 return -EIO; 71 } 72 73 p_le_ih = tp_item_head(path); 74 75 unfm_ptr = cpu_to_le32(unbh->b_blocknr); 76 77 if (is_statdata_le_ih(p_le_ih)) { 78 /* Insert new indirect item. */ 79 set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ 80 put_ih_item_len(&ind_ih, UNFM_P_SIZE); 81 PATH_LAST_POSITION(path)++; 82 retval = 83 reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, 84 (char *)&unfm_ptr); 85 } else { 86 /* Paste into last indirect item of an object. */ 87 retval = reiserfs_paste_into_item(th, path, &end_key, inode, 88 (char *)&unfm_ptr, 89 UNFM_P_SIZE); 90 } 91 if (retval) { 92 return retval; 93 } 94 /* 95 * note: from here there are two keys which have matching first 96 * three key components. They only differ by the fourth one. 97 */ 98 99 /* Set the key to search for the direct items of the file */ 100 make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, 101 4); 102 103 /* 104 * Move bytes from the direct items to the new unformatted node 105 * and delete them. 106 */ 107 while (1) { 108 int tail_size; 109 110 /* 111 * end_key.k_offset is set so, that we will always have found 112 * last item of the file 113 */ 114 if (search_for_position_by_key(sb, &end_key, path) == 115 POSITION_FOUND) 116 reiserfs_panic(sb, "PAP-14050", 117 "direct item (%K) not found", &end_key); 118 p_le_ih = tp_item_head(path); 119 RFALSE(!is_direct_le_ih(p_le_ih), 120 "vs-14055: direct item expected(%K), found %h", 121 &end_key, p_le_ih); 122 tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1)) 123 + ih_item_len(p_le_ih) - 1; 124 125 /* 126 * we only send the unbh pointer if the buffer is not 127 * up to date. this avoids overwriting good data from 128 * writepage() with old data from the disk or buffer cache 129 * Special case: unbh->b_page will be NULL if we are coming 130 * through DIRECT_IO handler here. 131 */ 132 if (!unbh->b_page || buffer_uptodate(unbh) 133 || PageUptodate(unbh->b_page)) { 134 up_to_date_bh = NULL; 135 } else { 136 up_to_date_bh = unbh; 137 } 138 retval = reiserfs_delete_item(th, path, &end_key, inode, 139 up_to_date_bh); 140 141 total_tail += retval; 142 143 /* done: file does not have direct items anymore */ 144 if (tail_size == retval) 145 break; 146 147 } 148 /* 149 * if we've copied bytes from disk into the page, we need to zero 150 * out the unused part of the block (it was not up to date before) 151 */ 152 if (up_to_date_bh) { 153 unsigned pgoff = 154 (tail_offset + total_tail - 1) & (PAGE_SIZE - 1); 155 char *kaddr = kmap_atomic(up_to_date_bh->b_page); 156 memset(kaddr + pgoff, 0, blk_size - total_tail); 157 kunmap_atomic(kaddr); 158 } 159 160 REISERFS_I(inode)->i_first_direct_byte = U32_MAX; 161 162 return 0; 163 } 164 165 /* stolen from fs/buffer.c */ 166 void reiserfs_unmap_buffer(struct buffer_head *bh) 167 { 168 lock_buffer(bh); 169 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { 170 BUG(); 171 } 172 clear_buffer_dirty(bh); 173 /* 174 * Remove the buffer from whatever list it belongs to. We are mostly 175 * interested in removing it from per-sb j_dirty_buffers list, to avoid 176 * BUG() on attempt to write not mapped buffer 177 */ 178 if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { 179 struct inode *inode = bh->b_page->mapping->host; 180 struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); 181 spin_lock(&j->j_dirty_buffers_lock); 182 list_del_init(&bh->b_assoc_buffers); 183 reiserfs_free_jh(bh); 184 spin_unlock(&j->j_dirty_buffers_lock); 185 } 186 clear_buffer_mapped(bh); 187 clear_buffer_req(bh); 188 clear_buffer_new(bh); 189 bh->b_bdev = NULL; 190 unlock_buffer(bh); 191 } 192 193 /* 194 * this first locks inode (neither reads nor sync are permitted), 195 * reads tail through page cache, insert direct item. When direct item 196 * inserted successfully inode is left locked. Return value is always 197 * what we expect from it (number of cut bytes). But when tail remains 198 * in the unformatted node, we set mode to SKIP_BALANCING and unlock 199 * inode 200 */ 201 int indirect2direct(struct reiserfs_transaction_handle *th, 202 struct inode *inode, struct page *page, 203 struct treepath *path, /* path to the indirect item. */ 204 const struct cpu_key *item_key, /* Key to look for 205 * unformatted node 206 * pointer to be cut. */ 207 loff_t n_new_file_size, /* New file size. */ 208 char *mode) 209 { 210 struct super_block *sb = inode->i_sb; 211 struct item_head s_ih; 212 unsigned long block_size = sb->s_blocksize; 213 char *tail; 214 int tail_len, round_tail_len; 215 loff_t pos, pos1; /* position of first byte of the tail */ 216 struct cpu_key key; 217 218 BUG_ON(!th->t_trans_id); 219 220 REISERFS_SB(sb)->s_indirect2direct++; 221 222 *mode = M_SKIP_BALANCING; 223 224 /* store item head path points to. */ 225 copy_item_head(&s_ih, tp_item_head(path)); 226 227 tail_len = (n_new_file_size & (block_size - 1)); 228 if (get_inode_sd_version(inode) == STAT_DATA_V2) 229 round_tail_len = ROUND_UP(tail_len); 230 else 231 round_tail_len = tail_len; 232 233 pos = 234 le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 235 1) * sb->s_blocksize; 236 pos1 = pos; 237 238 /* 239 * we are protected by i_mutex. The tail can not disapper, not 240 * append can be done either 241 * we are in truncate or packing tail in file_release 242 */ 243 244 tail = (char *)kmap(page); /* this can schedule */ 245 246 if (path_changed(&s_ih, path)) { 247 /* re-search indirect item */ 248 if (search_for_position_by_key(sb, item_key, path) 249 == POSITION_NOT_FOUND) 250 reiserfs_panic(sb, "PAP-5520", 251 "item to be converted %K does not exist", 252 item_key); 253 copy_item_head(&s_ih, tp_item_head(path)); 254 #ifdef CONFIG_REISERFS_CHECK 255 pos = le_ih_k_offset(&s_ih) - 1 + 256 (ih_item_len(&s_ih) / UNFM_P_SIZE - 257 1) * sb->s_blocksize; 258 if (pos != pos1) 259 reiserfs_panic(sb, "vs-5530", "tail position " 260 "changed while we were reading it"); 261 #endif 262 } 263 264 /* Set direct item header to insert. */ 265 make_le_item_head(&s_ih, NULL, get_inode_item_key_version(inode), 266 pos1 + 1, TYPE_DIRECT, round_tail_len, 267 0xffff /*ih_free_space */ ); 268 269 /* 270 * we want a pointer to the first byte of the tail in the page. 271 * the page was locked and this part of the page was up to date when 272 * indirect2direct was called, so we know the bytes are still valid 273 */ 274 tail = tail + (pos & (PAGE_SIZE - 1)); 275 276 PATH_LAST_POSITION(path)++; 277 278 key = *item_key; 279 set_cpu_key_k_type(&key, TYPE_DIRECT); 280 key.key_length = 4; 281 /* Insert tail as new direct item in the tree */ 282 if (reiserfs_insert_item(th, path, &key, &s_ih, inode, 283 tail ? tail : NULL) < 0) { 284 /* 285 * No disk memory. So we can not convert last unformatted node 286 * to the direct item. In this case we used to adjust 287 * indirect items's ih_free_space. Now ih_free_space is not 288 * used, it would be ideal to write zeros to corresponding 289 * unformatted node. For now i_size is considered as guard for 290 * going out of file size 291 */ 292 kunmap(page); 293 return block_size - round_tail_len; 294 } 295 kunmap(page); 296 297 /* make sure to get the i_blocks changes from reiserfs_insert_item */ 298 reiserfs_update_sd(th, inode); 299 300 /* 301 * note: we have now the same as in above direct2indirect 302 * conversion: there are two keys which have matching first three 303 * key components. They only differ by the fourth one. 304 */ 305 306 /* 307 * We have inserted new direct item and must remove last 308 * unformatted node. 309 */ 310 *mode = M_CUT; 311 312 /* we store position of first direct item in the in-core inode */ 313 /* mark_file_with_tail (inode, pos1 + 1); */ 314 REISERFS_I(inode)->i_first_direct_byte = pos1 + 1; 315 316 return block_size - round_tail_len; 317 } 318