1 /* 2 * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details 3 */ 4 5 #include <linux/time.h> 6 #include <linux/pagemap.h> 7 #include <linux/buffer_head.h> 8 #include <linux/reiserfs_fs.h> 9 10 /* access to tail : when one is going to read tail it must make sure, that is not running. 11 direct2indirect and indirect2direct can not run concurrently */ 12 13 /* Converts direct items to an unformatted node. Panics if file has no 14 tail. -ENOSPC if no disk space for conversion */ 15 /* path points to first direct item of the file regarless of how many of 16 them are there */ 17 int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, 18 struct treepath *path, struct buffer_head *unbh, 19 loff_t tail_offset) 20 { 21 struct super_block *sb = inode->i_sb; 22 struct buffer_head *up_to_date_bh; 23 struct item_head *p_le_ih = PATH_PITEM_HEAD(path); 24 unsigned long total_tail = 0; 25 struct cpu_key end_key; /* Key to search for the last byte of the 26 converted item. */ 27 struct item_head ind_ih; /* new indirect item to be inserted or 28 key of unfm pointer to be pasted */ 29 int n_blk_size, n_retval; /* returned value for reiserfs_insert_item and clones */ 30 unp_t unfm_ptr; /* Handle on an unformatted node 31 that will be inserted in the 32 tree. */ 33 34 BUG_ON(!th->t_trans_id); 35 36 REISERFS_SB(sb)->s_direct2indirect++; 37 38 n_blk_size = sb->s_blocksize; 39 40 /* and key to search for append or insert pointer to the new 41 unformatted node. */ 42 copy_item_head(&ind_ih, p_le_ih); 43 set_le_ih_k_offset(&ind_ih, tail_offset); 44 set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); 45 46 /* Set the key to search for the place for new unfm pointer */ 47 make_cpu_key(&end_key, inode, tail_offset, TYPE_INDIRECT, 4); 48 49 // FIXME: we could avoid this 50 if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { 51 reiserfs_warning(sb, "PAP-14030: direct2indirect: " 52 "pasted or inserted byte exists in the tree %K. " 53 "Use fsck to repair.", &end_key); 54 pathrelse(path); 55 return -EIO; 56 } 57 58 p_le_ih = PATH_PITEM_HEAD(path); 59 60 unfm_ptr = cpu_to_le32(unbh->b_blocknr); 61 62 if (is_statdata_le_ih(p_le_ih)) { 63 /* Insert new indirect item. */ 64 set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ 65 put_ih_item_len(&ind_ih, UNFM_P_SIZE); 66 PATH_LAST_POSITION(path)++; 67 n_retval = 68 reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, 69 (char *)&unfm_ptr); 70 } else { 71 /* Paste into last indirect item of an object. */ 72 n_retval = reiserfs_paste_into_item(th, path, &end_key, inode, 73 (char *)&unfm_ptr, 74 UNFM_P_SIZE); 75 } 76 if (n_retval) { 77 return n_retval; 78 } 79 // note: from here there are two keys which have matching first 80 // three key components. They only differ by the fourth one. 81 82 /* Set the key to search for the direct items of the file */ 83 make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, 84 4); 85 86 /* Move bytes from the direct items to the new unformatted node 87 and delete them. */ 88 while (1) { 89 int tail_size; 90 91 /* end_key.k_offset is set so, that we will always have found 92 last item of the file */ 93 if (search_for_position_by_key(sb, &end_key, path) == 94 POSITION_FOUND) 95 reiserfs_panic(sb, 96 "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", 101 &end_key, p_le_ih); 102 tail_size = (le_ih_k_offset(p_le_ih) & (n_blk_size - 1)) 103 + ih_item_len(p_le_ih) - 1; 104 105 /* 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 108 ** Special case: unbh->b_page will be NULL if we are coming through 109 ** DIRECT_IO handler here. 110 */ 111 if (!unbh->b_page || buffer_uptodate(unbh) 112 || PageUptodate(unbh->b_page)) { 113 up_to_date_bh = NULL; 114 } else { 115 up_to_date_bh = unbh; 116 } 117 n_retval = reiserfs_delete_item(th, path, &end_key, inode, 118 up_to_date_bh); 119 120 total_tail += n_retval; 121 if (tail_size == n_retval) 122 // done: file does not have direct items anymore 123 break; 124 125 } 126 /* if we've copied bytes from disk into the page, we need to zero 127 ** out the unused part of the block (it was not up to date before) 128 */ 129 if (up_to_date_bh) { 130 unsigned pgoff = 131 (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1); 132 char *kaddr = kmap_atomic(up_to_date_bh->b_page, KM_USER0); 133 memset(kaddr + pgoff, 0, n_blk_size - total_tail); 134 kunmap_atomic(kaddr, KM_USER0); 135 } 136 137 REISERFS_I(inode)->i_first_direct_byte = U32_MAX; 138 139 return 0; 140 } 141 142 /* stolen from fs/buffer.c */ 143 void reiserfs_unmap_buffer(struct buffer_head *bh) 144 { 145 lock_buffer(bh); 146 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { 147 BUG(); 148 } 149 clear_buffer_dirty(bh); 150 /* Remove the buffer from whatever list it belongs to. We are mostly 151 interested in removing it from per-sb j_dirty_buffers list, to avoid 152 BUG() on attempt to write not mapped buffer */ 153 if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { 154 struct inode *inode = bh->b_page->mapping->host; 155 struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); 156 spin_lock(&j->j_dirty_buffers_lock); 157 list_del_init(&bh->b_assoc_buffers); 158 reiserfs_free_jh(bh); 159 spin_unlock(&j->j_dirty_buffers_lock); 160 } 161 clear_buffer_mapped(bh); 162 clear_buffer_req(bh); 163 clear_buffer_new(bh); 164 bh->b_bdev = NULL; 165 unlock_buffer(bh); 166 } 167 168 /* this first locks inode (neither reads nor sync are permitted), 169 reads tail through page cache, insert direct item. When direct item 170 inserted successfully inode is left locked. Return value is always 171 what we expect from it (number of cut bytes). But when tail remains 172 in the unformatted node, we set mode to SKIP_BALANCING and unlock 173 inode */ 174 int indirect2direct(struct reiserfs_transaction_handle *th, struct inode *p_s_inode, struct page *page, struct treepath *p_s_path, /* path to the indirect item. */ 175 const struct cpu_key *p_s_item_key, /* Key to look for unformatted node pointer to be cut. */ 176 loff_t n_new_file_size, /* New file size. */ 177 char *p_c_mode) 178 { 179 struct super_block *p_s_sb = p_s_inode->i_sb; 180 struct item_head s_ih; 181 unsigned long n_block_size = p_s_sb->s_blocksize; 182 char *tail; 183 int tail_len, round_tail_len; 184 loff_t pos, pos1; /* position of first byte of the tail */ 185 struct cpu_key key; 186 187 BUG_ON(!th->t_trans_id); 188 189 REISERFS_SB(p_s_sb)->s_indirect2direct++; 190 191 *p_c_mode = M_SKIP_BALANCING; 192 193 /* store item head path points to. */ 194 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); 195 196 tail_len = (n_new_file_size & (n_block_size - 1)); 197 if (get_inode_sd_version(p_s_inode) == STAT_DATA_V2) 198 round_tail_len = ROUND_UP(tail_len); 199 else 200 round_tail_len = tail_len; 201 202 pos = 203 le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 204 1) * p_s_sb->s_blocksize; 205 pos1 = pos; 206 207 // we are protected by i_mutex. The tail can not disapper, not 208 // append can be done either 209 // we are in truncate or packing tail in file_release 210 211 tail = (char *)kmap(page); /* this can schedule */ 212 213 if (path_changed(&s_ih, p_s_path)) { 214 /* re-search indirect item */ 215 if (search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path) 216 == POSITION_NOT_FOUND) 217 reiserfs_panic(p_s_sb, 218 "PAP-5520: indirect2direct: " 219 "item to be converted %K does not exist", 220 p_s_item_key); 221 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); 222 #ifdef CONFIG_REISERFS_CHECK 223 pos = le_ih_k_offset(&s_ih) - 1 + 224 (ih_item_len(&s_ih) / UNFM_P_SIZE - 225 1) * p_s_sb->s_blocksize; 226 if (pos != pos1) 227 reiserfs_panic(p_s_sb, "vs-5530: indirect2direct: " 228 "tail position changed while we were reading it"); 229 #endif 230 } 231 232 /* Set direct item header to insert. */ 233 make_le_item_head(&s_ih, NULL, get_inode_item_key_version(p_s_inode), 234 pos1 + 1, TYPE_DIRECT, round_tail_len, 235 0xffff /*ih_free_space */ ); 236 237 /* we want a pointer to the first byte of the tail in the page. 238 ** the page was locked and this part of the page was up to date when 239 ** indirect2direct was called, so we know the bytes are still valid 240 */ 241 tail = tail + (pos & (PAGE_CACHE_SIZE - 1)); 242 243 PATH_LAST_POSITION(p_s_path)++; 244 245 key = *p_s_item_key; 246 set_cpu_key_k_type(&key, TYPE_DIRECT); 247 key.key_length = 4; 248 /* Insert tail as new direct item in the tree */ 249 if (reiserfs_insert_item(th, p_s_path, &key, &s_ih, p_s_inode, 250 tail ? tail : NULL) < 0) { 251 /* No disk memory. So we can not convert last unformatted node 252 to the direct item. In this case we used to adjust 253 indirect items's ih_free_space. Now ih_free_space is not 254 used, it would be ideal to write zeros to corresponding 255 unformatted node. For now i_size is considered as guard for 256 going out of file size */ 257 kunmap(page); 258 return n_block_size - round_tail_len; 259 } 260 kunmap(page); 261 262 /* make sure to get the i_blocks changes from reiserfs_insert_item */ 263 reiserfs_update_sd(th, p_s_inode); 264 265 // note: we have now the same as in above direct2indirect 266 // conversion: there are two keys which have matching first three 267 // key components. They only differ by the fouhth one. 268 269 /* We have inserted new direct item and must remove last 270 unformatted node. */ 271 *p_c_mode = M_CUT; 272 273 /* we store position of first direct item in the in-core inode */ 274 //mark_file_with_tail (p_s_inode, pos1 + 1); 275 REISERFS_I(p_s_inode)->i_first_direct_byte = pos1 + 1; 276 277 return n_block_size - round_tail_len; 278 } 279