1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright 4 * details 5 */ 6 7 #include <linux/time.h> 8 #include <linux/pagemap.h> 9 #include <linux/buffer_head.h> 10 #include "reiserfs.h" 11 12 /* 13 * access to tail : when one is going to read tail it must make sure, that is 14 * not running. direct2indirect and indirect2direct can not run concurrently 15 */ 16 17 /* 18 * Converts direct items to an unformatted node. Panics if file has no 19 * tail. -ENOSPC if no disk space for conversion 20 */ 21 /* 22 * path points to first direct item of the file regardless of how many of 23 * them are there 24 */ 25 int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, 26 struct treepath *path, struct buffer_head *unbh, 27 loff_t tail_offset) 28 { 29 struct super_block *sb = inode->i_sb; 30 struct buffer_head *up_to_date_bh; 31 struct item_head *p_le_ih = tp_item_head(path); 32 unsigned long total_tail = 0; 33 34 /* Key to search for the last byte of the converted item. */ 35 struct cpu_key end_key; 36 37 /* 38 * new indirect item to be inserted or key 39 * of unfm pointer to be pasted 40 */ 41 struct item_head ind_ih; 42 int blk_size; 43 /* returned value for reiserfs_insert_item and clones */ 44 int retval; 45 /* Handle on an unformatted node that will be inserted in the tree. */ 46 unp_t unfm_ptr; 47 48 BUG_ON(!th->t_trans_id); 49 50 REISERFS_SB(sb)->s_direct2indirect++; 51 52 blk_size = sb->s_blocksize; 53 54 /* 55 * and key to search for append or insert pointer to the new 56 * unformatted node. 57 */ 58 copy_item_head(&ind_ih, p_le_ih); 59 set_le_ih_k_offset(&ind_ih, tail_offset); 60 set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); 61 62 /* Set the key to search for the place for new unfm pointer */ 63 make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); 64 65 /* FIXME: we could avoid this */ 66 if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { 67 reiserfs_error(sb, "PAP-14030", 68 "pasted or inserted byte exists in " 69 "the tree %K. Use fsck to repair.", &end_key); 70 pathrelse(path); 71 return -EIO; 72 } 73 74 p_le_ih = tp_item_head(path); 75 76 unfm_ptr = cpu_to_le32(unbh->b_blocknr); 77 78 if (is_statdata_le_ih(p_le_ih)) { 79 /* Insert new indirect item. */ 80 set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ 81 put_ih_item_len(&ind_ih, UNFM_P_SIZE); 82 PATH_LAST_POSITION(path)++; 83 retval = 84 reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, 85 (char *)&unfm_ptr); 86 } else { 87 /* Paste into last indirect item of an object. */ 88 retval = reiserfs_paste_into_item(th, path, &end_key, inode, 89 (char *)&unfm_ptr, 90 UNFM_P_SIZE); 91 } 92 if (retval) { 93 return retval; 94 } 95 /* 96 * note: from here there are two keys which have matching first 97 * three key components. They only differ by the fourth one. 98 */ 99 100 /* Set the key to search for the direct items of the file */ 101 make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, 102 4); 103 104 /* 105 * Move bytes from the direct items to the new unformatted node 106 * and delete them. 107 */ 108 while (1) { 109 int tail_size; 110 111 /* 112 * end_key.k_offset is set so, that we will always have found 113 * last item of the file 114 */ 115 if (search_for_position_by_key(sb, &end_key, path) == 116 POSITION_FOUND) 117 reiserfs_panic(sb, "PAP-14050", 118 "direct item (%K) not found", &end_key); 119 p_le_ih = tp_item_head(path); 120 RFALSE(!is_direct_le_ih(p_le_ih), 121 "vs-14055: direct item expected(%K), found %h", 122 &end_key, p_le_ih); 123 tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1)) 124 + ih_item_len(p_le_ih) - 1; 125 126 /* 127 * we only send the unbh pointer if the buffer is not 128 * up to date. this avoids overwriting good data from 129 * writepage() with old data from the disk or buffer cache 130 * Special case: unbh->b_page will be NULL if we are coming 131 * through DIRECT_IO handler here. 132 */ 133 if (!unbh->b_page || buffer_uptodate(unbh) 134 || PageUptodate(unbh->b_page)) { 135 up_to_date_bh = NULL; 136 } else { 137 up_to_date_bh = unbh; 138 } 139 retval = reiserfs_delete_item(th, path, &end_key, inode, 140 up_to_date_bh); 141 142 total_tail += retval; 143 144 /* done: file does not have direct items anymore */ 145 if (tail_size == retval) 146 break; 147 148 } 149 /* 150 * if we've copied bytes from disk into the page, we need to zero 151 * out the unused part of the block (it was not up to date before) 152 */ 153 if (up_to_date_bh) { 154 unsigned pgoff = 155 (tail_offset + total_tail - 1) & (PAGE_SIZE - 1); 156 char *kaddr = kmap_atomic(up_to_date_bh->b_page); 157 memset(kaddr + pgoff, 0, blk_size - total_tail); 158 kunmap_atomic(kaddr); 159 } 160 161 REISERFS_I(inode)->i_first_direct_byte = U32_MAX; 162 163 return 0; 164 } 165 166 /* stolen from fs/buffer.c */ 167 void reiserfs_unmap_buffer(struct buffer_head *bh) 168 { 169 lock_buffer(bh); 170 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { 171 BUG(); 172 } 173 clear_buffer_dirty(bh); 174 /* 175 * Remove the buffer from whatever list it belongs to. We are mostly 176 * interested in removing it from per-sb j_dirty_buffers list, to avoid 177 * BUG() on attempt to write not mapped buffer 178 */ 179 if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { 180 struct inode *inode = bh->b_folio->mapping->host; 181 struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); 182 spin_lock(&j->j_dirty_buffers_lock); 183 list_del_init(&bh->b_assoc_buffers); 184 reiserfs_free_jh(bh); 185 spin_unlock(&j->j_dirty_buffers_lock); 186 } 187 clear_buffer_mapped(bh); 188 clear_buffer_req(bh); 189 clear_buffer_new(bh); 190 bh->b_bdev = NULL; 191 unlock_buffer(bh); 192 } 193 194 /* 195 * this first locks inode (neither reads nor sync are permitted), 196 * reads tail through page cache, insert direct item. When direct item 197 * inserted successfully inode is left locked. Return value is always 198 * what we expect from it (number of cut bytes). But when tail remains 199 * in the unformatted node, we set mode to SKIP_BALANCING and unlock 200 * inode 201 */ 202 int indirect2direct(struct reiserfs_transaction_handle *th, 203 struct inode *inode, struct page *page, 204 struct treepath *path, /* path to the indirect item. */ 205 const struct cpu_key *item_key, /* Key to look for 206 * unformatted node 207 * pointer to be cut. */ 208 loff_t n_new_file_size, /* New file size. */ 209 char *mode) 210 { 211 struct super_block *sb = inode->i_sb; 212 struct item_head s_ih; 213 unsigned long block_size = sb->s_blocksize; 214 char *tail; 215 int tail_len, round_tail_len; 216 loff_t pos, pos1; /* position of first byte of the tail */ 217 struct cpu_key key; 218 219 BUG_ON(!th->t_trans_id); 220 221 REISERFS_SB(sb)->s_indirect2direct++; 222 223 *mode = M_SKIP_BALANCING; 224 225 /* store item head path points to. */ 226 copy_item_head(&s_ih, tp_item_head(path)); 227 228 tail_len = (n_new_file_size & (block_size - 1)); 229 if (get_inode_sd_version(inode) == STAT_DATA_V2) 230 round_tail_len = ROUND_UP(tail_len); 231 else 232 round_tail_len = tail_len; 233 234 pos = 235 le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 236 1) * sb->s_blocksize; 237 pos1 = pos; 238 239 /* 240 * we are protected by i_mutex. The tail can not disapper, not 241 * append can be done either 242 * we are in truncate or packing tail in file_release 243 */ 244 245 tail = (char *)kmap(page); /* this can schedule */ 246 247 if (path_changed(&s_ih, path)) { 248 /* re-search indirect item */ 249 if (search_for_position_by_key(sb, item_key, path) 250 == POSITION_NOT_FOUND) 251 reiserfs_panic(sb, "PAP-5520", 252 "item to be converted %K does not exist", 253 item_key); 254 copy_item_head(&s_ih, tp_item_head(path)); 255 #ifdef CONFIG_REISERFS_CHECK 256 pos = le_ih_k_offset(&s_ih) - 1 + 257 (ih_item_len(&s_ih) / UNFM_P_SIZE - 258 1) * sb->s_blocksize; 259 if (pos != pos1) 260 reiserfs_panic(sb, "vs-5530", "tail position " 261 "changed while we were reading it"); 262 #endif 263 } 264 265 /* Set direct item header to insert. */ 266 make_le_item_head(&s_ih, NULL, get_inode_item_key_version(inode), 267 pos1 + 1, TYPE_DIRECT, round_tail_len, 268 0xffff /*ih_free_space */ ); 269 270 /* 271 * we want a pointer to the first byte of the tail in the page. 272 * the page was locked and this part of the page was up to date when 273 * indirect2direct was called, so we know the bytes are still valid 274 */ 275 tail = tail + (pos & (PAGE_SIZE - 1)); 276 277 PATH_LAST_POSITION(path)++; 278 279 key = *item_key; 280 set_cpu_key_k_type(&key, TYPE_DIRECT); 281 key.key_length = 4; 282 /* Insert tail as new direct item in the tree */ 283 if (reiserfs_insert_item(th, path, &key, &s_ih, inode, 284 tail ? tail : NULL) < 0) { 285 /* 286 * No disk memory. So we can not convert last unformatted node 287 * to the direct item. In this case we used to adjust 288 * indirect items's ih_free_space. Now ih_free_space is not 289 * used, it would be ideal to write zeros to corresponding 290 * unformatted node. For now i_size is considered as guard for 291 * going out of file size 292 */ 293 kunmap(page); 294 return block_size - round_tail_len; 295 } 296 kunmap(page); 297 298 /* make sure to get the i_blocks changes from reiserfs_insert_item */ 299 reiserfs_update_sd(th, inode); 300 301 /* 302 * note: we have now the same as in above direct2indirect 303 * conversion: there are two keys which have matching first three 304 * key components. They only differ by the fourth one. 305 */ 306 307 /* 308 * We have inserted new direct item and must remove last 309 * unformatted node. 310 */ 311 *mode = M_CUT; 312 313 /* we store position of first direct item in the in-core inode */ 314 /* mark_file_with_tail (inode, pos1 + 1); */ 315 REISERFS_I(inode)->i_first_direct_byte = pos1 + 1; 316 317 return block_size - round_tail_len; 318 } 319