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 */ 17int 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 if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) { 50 reiserfs_warning(sb, "PAP-14030: direct2indirect: " 51 "pasted or inserted byte exists in the tree %K. " 52 "Use fsck to repair.", &end_key); 53 pathrelse(path); 54 return -EIO; 55 } 56 57 p_le_ih = PATH_PITEM_HEAD(path); 58 59 unfm_ptr = cpu_to_le32(unbh->b_blocknr); 60 61 if (is_statdata_le_ih(p_le_ih)) { 62 /* Insert new indirect item. */ 63 set_ih_free_space(&ind_ih, 0); /* delete at nearest future */ 64 put_ih_item_len(&ind_ih, UNFM_P_SIZE); 65 PATH_LAST_POSITION(path)++; 66 n_retval = 67 reiserfs_insert_item(th, path, &end_key, &ind_ih, inode, 68 (char *)&unfm_ptr); 69 } else { 70 /* Paste into last indirect item of an object. */ 71 n_retval = reiserfs_paste_into_item(th, path, &end_key, inode, 72 (char *)&unfm_ptr, 73 UNFM_P_SIZE); 74 } 75 if (n_retval) { 76 return n_retval; 77 } 78 // note: from here there are two keys which have matching first 79 // three key components. They only differ by the fourth one. 80 81 /* Set the key to search for the direct items of the file */ 82 make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, 83 4); 84 85 /* Move bytes from the direct items to the new unformatted node 86 and delete them. */ 87 while (1) { 88 int tail_size; 89 90 /* end_key.k_offset is set so, that we will always have found 91 last item of the file */ 92 if (search_for_position_by_key(sb, &end_key, path) == 93 POSITION_FOUND) 94 reiserfs_panic(sb, 95 "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", 100 &end_key, p_le_ih); 101 tail_size = (le_ih_k_offset(p_le_ih) & (n_blk_size - 1)) 102 + ih_item_len(p_le_ih) - 1; 103 104 /* 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. 109 */ 110 if (!unbh->b_page || buffer_uptodate(unbh) 111 || PageUptodate(unbh->b_page)) { 112 up_to_date_bh = NULL; 113 } else { 114 up_to_date_bh = unbh; 115 } 116 n_retval = reiserfs_delete_item(th, path, &end_key, inode, 117 up_to_date_bh); 118 119 total_tail += n_retval; 120 if (tail_size == n_retval) 121 // done: file does not have direct items anymore 122 break; 123 124 } 125 /* if we've copied bytes from disk into the page, we need to zero 126 ** out the unused part of the block (it was not up to date before) 127 */ 128 if (up_to_date_bh) { 129 unsigned pgoff = 130 (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1); 131 char *kaddr = kmap_atomic(up_to_date_bh->b_page, KM_USER0); 132 memset(kaddr + pgoff, 0, n_blk_size - total_tail); 133 kunmap_atomic(kaddr, KM_USER0); 134 } 135 136 REISERFS_I(inode)->i_first_direct_byte = U32_MAX; 137 138 return 0; 139} 140 141/* stolen from fs/buffer.c */ 142void reiserfs_unmap_buffer(struct buffer_head *bh) 143{ 144 lock_buffer(bh); 145 if (buffer_journaled(bh) || buffer_journal_dirty(bh)) { 146 BUG(); 147 } 148 clear_buffer_dirty(bh); 149 /* Remove the buffer from whatever list it belongs to. We are mostly 150 interested in removing it from per-sb j_dirty_buffers list, to avoid 151 BUG() on attempt to write not mapped buffer */ 152 if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { 153 struct inode *inode = bh->b_page->mapping->host; 154 struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); 155 spin_lock(&j->j_dirty_buffers_lock); 156 list_del_init(&bh->b_assoc_buffers); 157 reiserfs_free_jh(bh); 158 spin_unlock(&j->j_dirty_buffers_lock); 159 } 160 clear_buffer_mapped(bh); 161 clear_buffer_req(bh); 162 clear_buffer_new(bh); 163 bh->b_bdev = NULL; 164 unlock_buffer(bh); 165} 166 167/* this first locks inode (neither reads nor sync are permitted), 168 reads tail through page cache, insert direct item. When direct item 169 inserted successfully inode is left locked. Return value is always 170 what we expect from it (number of cut bytes). But when tail remains 171 in the unformatted node, we set mode to SKIP_BALANCING and unlock 172 inode */ 173int indirect2direct(struct reiserfs_transaction_handle *th, struct inode *p_s_inode, struct page *page, struct treepath *p_s_path, /* path to the indirect item. */ 174 const struct cpu_key *p_s_item_key, /* Key to look for unformatted node pointer to be cut. */ 175 loff_t n_new_file_size, /* New file size. */ 176 char *p_c_mode) 177{ 178 struct super_block *p_s_sb = p_s_inode->i_sb; 179 struct item_head s_ih; 180 unsigned long n_block_size = p_s_sb->s_blocksize; 181 char *tail; 182 int tail_len, round_tail_len; 183 loff_t pos, pos1; /* position of first byte of the tail */ 184 struct cpu_key key; 185 186 BUG_ON(!th->t_trans_id); 187 188 REISERFS_SB(p_s_sb)->s_indirect2direct++; 189 190 *p_c_mode = M_SKIP_BALANCING; 191 192 /* store item head path points to. */ 193 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); 194 195 tail_len = (n_new_file_size & (n_block_size - 1)); 196 if (get_inode_sd_version(p_s_inode) == STAT_DATA_V2) 197 round_tail_len = ROUND_UP(tail_len); 198 else 199 round_tail_len = tail_len; 200 201 pos = 202 le_ih_k_offset(&s_ih) - 1 + (ih_item_len(&s_ih) / UNFM_P_SIZE - 203 1) * p_s_sb->s_blocksize; 204 pos1 = pos; 205 206 // we are protected by i_mutex. The tail can not disapper, not 207 // append can be done either 208 // we are in truncate or packing tail in file_release 209 210 tail = (char *)kmap(page); /* this can schedule */ 211 212 if (path_changed(&s_ih, p_s_path)) { 213 /* re-search indirect item */ 214 if (search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path) 215 == POSITION_NOT_FOUND) 216 reiserfs_panic(p_s_sb, 217 "PAP-5520: indirect2direct: " 218 "item to be converted %K does not exist", 219 p_s_item_key); 220 copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); 221#ifdef CONFIG_REISERFS_CHECK 222 pos = le_ih_k_offset(&s_ih) - 1 + 223 (ih_item_len(&s_ih) / UNFM_P_SIZE - 224 1) * p_s_sb->s_blocksize; 225 if (pos != pos1) 226 reiserfs_panic(p_s_sb, "vs-5530: indirect2direct: " 227 "tail position changed while we were reading it"); 228#endif 229 } 230 231 /* Set direct item header to insert. */ 232 make_le_item_head(&s_ih, NULL, get_inode_item_key_version(p_s_inode), 233 pos1 + 1, TYPE_DIRECT, round_tail_len, 234 0xffff /*ih_free_space */ ); 235 236 /* we want a pointer to the first byte of the tail in the page. 237 ** the page was locked and this part of the page was up to date when 238 ** indirect2direct was called, so we know the bytes are still valid 239 */ 240 tail = tail + (pos & (PAGE_CACHE_SIZE - 1)); 241 242 PATH_LAST_POSITION(p_s_path)++; 243 244 key = *p_s_item_key; 245 set_cpu_key_k_type(&key, TYPE_DIRECT); 246 key.key_length = 4; 247 /* Insert tail as new direct item in the tree */ 248 if (reiserfs_insert_item(th, p_s_path, &key, &s_ih, p_s_inode, 249 tail ? tail : NULL) < 0) { 250 /* No disk memory. So we can not convert last unformatted node 251 to the direct item. In this case we used to adjust 252 indirect items's ih_free_space. Now ih_free_space is not 253 used, it would be ideal to write zeros to corresponding 254 unformatted node. For now i_size is considered as guard for 255 going out of file size */ 256 kunmap(page); 257 return n_block_size - round_tail_len; 258 } 259 kunmap(page); 260 261 /* make sure to get the i_blocks changes from reiserfs_insert_item */ 262 reiserfs_update_sd(th, p_s_inode); 263 264 // note: we have now the same as in above direct2indirect 265 // conversion: there are two keys which have matching first three 266 // key components. They only differ by the fouhth one. 267 268 /* We have inserted new direct item and must remove last 269 unformatted node. */ 270 *p_c_mode = M_CUT; 271 272 /* we store position of first direct item in the in-core inode */ 273 //mark_file_with_tail (p_s_inode, pos1 + 1); 274 REISERFS_I(p_s_inode)->i_first_direct_byte = pos1 + 1; 275 276 return n_block_size - round_tail_len; 277} 278