1 /* 2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README 3 */ 4 5 #include <linux/time.h> 6 #include <linux/reiserfs_fs.h> 7 #include <linux/reiserfs_acl.h> 8 #include <linux/reiserfs_xattr.h> 9 #include <asm/uaccess.h> 10 #include <linux/pagemap.h> 11 #include <linux/swap.h> 12 #include <linux/writeback.h> 13 #include <linux/blkdev.h> 14 #include <linux/buffer_head.h> 15 #include <linux/quotaops.h> 16 17 /* 18 ** We pack the tails of files on file close, not at the time they are written. 19 ** This implies an unnecessary copy of the tail and an unnecessary indirect item 20 ** insertion/balancing, for files that are written in one write. 21 ** It avoids unnecessary tail packings (balances) for files that are written in 22 ** multiple writes and are small enough to have tails. 23 ** 24 ** file_release is called by the VFS layer when the file is closed. If 25 ** this is the last open file descriptor, and the file 26 ** small enough to have a tail, and the tail is currently in an 27 ** unformatted node, the tail is converted back into a direct item. 28 ** 29 ** We use reiserfs_truncate_file to pack the tail, since it already has 30 ** all the conditions coded. 31 */ 32 static int reiserfs_file_release(struct inode *inode, struct file *filp) 33 { 34 35 struct reiserfs_transaction_handle th; 36 int err; 37 int jbegin_failure = 0; 38 39 BUG_ON(!S_ISREG(inode->i_mode)); 40 41 /* fast out for when nothing needs to be done */ 42 if ((atomic_read(&inode->i_count) > 1 || 43 !(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || 44 !tail_has_to_be_packed(inode)) && 45 REISERFS_I(inode)->i_prealloc_count <= 0) { 46 return 0; 47 } 48 49 mutex_lock(&inode->i_mutex); 50 51 mutex_lock(&(REISERFS_I(inode)->i_mmap)); 52 if (REISERFS_I(inode)->i_flags & i_ever_mapped) 53 REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask; 54 55 reiserfs_write_lock(inode->i_sb); 56 /* freeing preallocation only involves relogging blocks that 57 * are already in the current transaction. preallocation gets 58 * freed at the end of each transaction, so it is impossible for 59 * us to log any additional blocks (including quota blocks) 60 */ 61 err = journal_begin(&th, inode->i_sb, 1); 62 if (err) { 63 /* uh oh, we can't allow the inode to go away while there 64 * is still preallocation blocks pending. Try to join the 65 * aborted transaction 66 */ 67 jbegin_failure = err; 68 err = journal_join_abort(&th, inode->i_sb, 1); 69 70 if (err) { 71 /* hmpf, our choices here aren't good. We can pin the inode 72 * which will disallow unmount from every happening, we can 73 * do nothing, which will corrupt random memory on unmount, 74 * or we can forcibly remove the file from the preallocation 75 * list, which will leak blocks on disk. Lets pin the inode 76 * and let the admin know what is going on. 77 */ 78 igrab(inode); 79 reiserfs_warning(inode->i_sb, 80 "pinning inode %lu because the " 81 "preallocation can't be freed", 82 inode->i_ino); 83 goto out; 84 } 85 } 86 reiserfs_update_inode_transaction(inode); 87 88 #ifdef REISERFS_PREALLOCATE 89 reiserfs_discard_prealloc(&th, inode); 90 #endif 91 err = journal_end(&th, inode->i_sb, 1); 92 93 /* copy back the error code from journal_begin */ 94 if (!err) 95 err = jbegin_failure; 96 97 if (!err && atomic_read(&inode->i_count) <= 1 && 98 (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) && 99 tail_has_to_be_packed(inode)) { 100 /* if regular file is released by last holder and it has been 101 appended (we append by unformatted node only) or its direct 102 item(s) had to be converted, then it may have to be 103 indirect2direct converted */ 104 err = reiserfs_truncate_file(inode, 0); 105 } 106 out: 107 mutex_unlock(&(REISERFS_I(inode)->i_mmap)); 108 mutex_unlock(&inode->i_mutex); 109 reiserfs_write_unlock(inode->i_sb); 110 return err; 111 } 112 113 static int reiserfs_file_mmap(struct file *file, struct vm_area_struct *vma) 114 { 115 struct inode *inode; 116 117 inode = file->f_path.dentry->d_inode; 118 mutex_lock(&(REISERFS_I(inode)->i_mmap)); 119 REISERFS_I(inode)->i_flags |= i_ever_mapped; 120 mutex_unlock(&(REISERFS_I(inode)->i_mmap)); 121 122 return generic_file_mmap(file, vma); 123 } 124 125 static void reiserfs_vfs_truncate_file(struct inode *inode) 126 { 127 reiserfs_truncate_file(inode, 1); 128 } 129 130 /* Sync a reiserfs file. */ 131 132 /* 133 * FIXME: sync_mapping_buffers() never has anything to sync. Can 134 * be removed... 135 */ 136 137 static int reiserfs_sync_file(struct file *p_s_filp, 138 struct dentry *p_s_dentry, int datasync) 139 { 140 struct inode *p_s_inode = p_s_dentry->d_inode; 141 int n_err; 142 int barrier_done; 143 144 BUG_ON(!S_ISREG(p_s_inode->i_mode)); 145 n_err = sync_mapping_buffers(p_s_inode->i_mapping); 146 reiserfs_write_lock(p_s_inode->i_sb); 147 barrier_done = reiserfs_commit_for_inode(p_s_inode); 148 reiserfs_write_unlock(p_s_inode->i_sb); 149 if (barrier_done != 1 && reiserfs_barrier_flush(p_s_inode->i_sb)) 150 blkdev_issue_flush(p_s_inode->i_sb->s_bdev, NULL); 151 if (barrier_done < 0) 152 return barrier_done; 153 return (n_err < 0) ? -EIO : 0; 154 } 155 156 /* taken fs/buffer.c:__block_commit_write */ 157 int reiserfs_commit_page(struct inode *inode, struct page *page, 158 unsigned from, unsigned to) 159 { 160 unsigned block_start, block_end; 161 int partial = 0; 162 unsigned blocksize; 163 struct buffer_head *bh, *head; 164 unsigned long i_size_index = inode->i_size >> PAGE_CACHE_SHIFT; 165 int new; 166 int logit = reiserfs_file_data_log(inode); 167 struct super_block *s = inode->i_sb; 168 int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize; 169 struct reiserfs_transaction_handle th; 170 int ret = 0; 171 172 th.t_trans_id = 0; 173 blocksize = 1 << inode->i_blkbits; 174 175 if (logit) { 176 reiserfs_write_lock(s); 177 ret = journal_begin(&th, s, bh_per_page + 1); 178 if (ret) 179 goto drop_write_lock; 180 reiserfs_update_inode_transaction(inode); 181 } 182 for (bh = head = page_buffers(page), block_start = 0; 183 bh != head || !block_start; 184 block_start = block_end, bh = bh->b_this_page) { 185 186 new = buffer_new(bh); 187 clear_buffer_new(bh); 188 block_end = block_start + blocksize; 189 if (block_end <= from || block_start >= to) { 190 if (!buffer_uptodate(bh)) 191 partial = 1; 192 } else { 193 set_buffer_uptodate(bh); 194 if (logit) { 195 reiserfs_prepare_for_journal(s, bh, 1); 196 journal_mark_dirty(&th, s, bh); 197 } else if (!buffer_dirty(bh)) { 198 mark_buffer_dirty(bh); 199 /* do data=ordered on any page past the end 200 * of file and any buffer marked BH_New. 201 */ 202 if (reiserfs_data_ordered(inode->i_sb) && 203 (new || page->index >= i_size_index)) { 204 reiserfs_add_ordered_list(inode, bh); 205 } 206 } 207 } 208 } 209 if (logit) { 210 ret = journal_end(&th, s, bh_per_page + 1); 211 drop_write_lock: 212 reiserfs_write_unlock(s); 213 } 214 /* 215 * If this is a partial write which happened to make all buffers 216 * uptodate then we can optimize away a bogus readpage() for 217 * the next read(). Here we 'discover' whether the page went 218 * uptodate as a result of this (potentially partial) write. 219 */ 220 if (!partial) 221 SetPageUptodate(page); 222 return ret; 223 } 224 225 /* Write @count bytes at position @ppos in a file indicated by @file 226 from the buffer @buf. 227 228 generic_file_write() is only appropriate for filesystems that are not seeking to optimize performance and want 229 something simple that works. It is not for serious use by general purpose filesystems, excepting the one that it was 230 written for (ext2/3). This is for several reasons: 231 232 * It has no understanding of any filesystem specific optimizations. 233 234 * It enters the filesystem repeatedly for each page that is written. 235 236 * It depends on reiserfs_get_block() function which if implemented by reiserfs performs costly search_by_key 237 * operation for each page it is supplied with. By contrast reiserfs_file_write() feeds as much as possible at a time 238 * to reiserfs which allows for fewer tree traversals. 239 240 * Each indirect pointer insertion takes a lot of cpu, because it involves memory moves inside of blocks. 241 242 * Asking the block allocation code for blocks one at a time is slightly less efficient. 243 244 All of these reasons for not using only generic file write were understood back when reiserfs was first miscoded to 245 use it, but we were in a hurry to make code freeze, and so it couldn't be revised then. This new code should make 246 things right finally. 247 248 Future Features: providing search_by_key with hints. 249 250 */ 251 static ssize_t reiserfs_file_write(struct file *file, /* the file we are going to write into */ 252 const char __user * buf, /* pointer to user supplied data 253 (in userspace) */ 254 size_t count, /* amount of bytes to write */ 255 loff_t * ppos /* pointer to position in file that we start writing at. Should be updated to 256 * new current position before returning. */ 257 ) 258 { 259 struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to. 260 /* To simplify coding at this time, we store 261 locked pages in array for now */ 262 struct reiserfs_transaction_handle th; 263 th.t_trans_id = 0; 264 265 /* If a filesystem is converted from 3.5 to 3.6, we'll have v3.5 items 266 * lying around (most of the disk, in fact). Despite the filesystem 267 * now being a v3.6 format, the old items still can't support large 268 * file sizes. Catch this case here, as the rest of the VFS layer is 269 * oblivious to the different limitations between old and new items. 270 * reiserfs_setattr catches this for truncates. This chunk is lifted 271 * from generic_write_checks. */ 272 if (get_inode_item_key_version (inode) == KEY_FORMAT_3_5 && 273 *ppos + count > MAX_NON_LFS) { 274 if (*ppos >= MAX_NON_LFS) { 275 return -EFBIG; 276 } 277 if (count > MAX_NON_LFS - (unsigned long)*ppos) 278 count = MAX_NON_LFS - (unsigned long)*ppos; 279 } 280 281 return do_sync_write(file, buf, count, ppos); 282 } 283 284 const struct file_operations reiserfs_file_operations = { 285 .read = do_sync_read, 286 .write = reiserfs_file_write, 287 .ioctl = reiserfs_ioctl, 288 #ifdef CONFIG_COMPAT 289 .compat_ioctl = reiserfs_compat_ioctl, 290 #endif 291 .mmap = reiserfs_file_mmap, 292 .open = generic_file_open, 293 .release = reiserfs_file_release, 294 .fsync = reiserfs_sync_file, 295 .aio_read = generic_file_aio_read, 296 .aio_write = generic_file_aio_write, 297 .splice_read = generic_file_splice_read, 298 .splice_write = generic_file_splice_write, 299 .llseek = generic_file_llseek, 300 }; 301 302 const struct inode_operations reiserfs_file_inode_operations = { 303 .truncate = reiserfs_vfs_truncate_file, 304 .setattr = reiserfs_setattr, 305 .setxattr = reiserfs_setxattr, 306 .getxattr = reiserfs_getxattr, 307 .listxattr = reiserfs_listxattr, 308 .removexattr = reiserfs_removexattr, 309 .permission = reiserfs_permission, 310 }; 311