| 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 | } |