1 /* 2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README 3 */ 4 5 #include <linux/time.h> 6 #include "reiserfs.h" 7 #include "acl.h" 8 #include "xattr.h" 9 #include <linux/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 if (atomic_add_unless(&REISERFS_I(inode)->openers, -1, 1)) 42 return 0; 43 44 mutex_lock(&REISERFS_I(inode)->tailpack); 45 46 if (!atomic_dec_and_test(&REISERFS_I(inode)->openers)) { 47 mutex_unlock(&REISERFS_I(inode)->tailpack); 48 return 0; 49 } 50 51 /* fast out for when nothing needs to be done */ 52 if ((!(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || 53 !tail_has_to_be_packed(inode)) && 54 REISERFS_I(inode)->i_prealloc_count <= 0) { 55 mutex_unlock(&REISERFS_I(inode)->tailpack); 56 return 0; 57 } 58 59 reiserfs_write_lock(inode->i_sb); 60 /* 61 * freeing preallocation only involves relogging blocks that 62 * are already in the current transaction. preallocation gets 63 * freed at the end of each transaction, so it is impossible for 64 * us to log any additional blocks (including quota blocks) 65 */ 66 err = journal_begin(&th, inode->i_sb, 1); 67 if (err) { 68 /* 69 * uh oh, we can't allow the inode to go away while there 70 * is still preallocation blocks pending. Try to join the 71 * aborted transaction 72 */ 73 jbegin_failure = err; 74 err = journal_join_abort(&th, inode->i_sb); 75 76 if (err) { 77 /* 78 * hmpf, our choices here aren't good. We can pin 79 * the inode which will disallow unmount from ever 80 * happening, we can do nothing, which will corrupt 81 * random memory on unmount, or we can forcibly 82 * remove the file from the preallocation list, which 83 * will leak blocks on disk. Lets pin the inode 84 * and let the admin know what is going on. 85 */ 86 igrab(inode); 87 reiserfs_warning(inode->i_sb, "clm-9001", 88 "pinning inode %lu because the " 89 "preallocation can't be freed", 90 inode->i_ino); 91 goto out; 92 } 93 } 94 reiserfs_update_inode_transaction(inode); 95 96 #ifdef REISERFS_PREALLOCATE 97 reiserfs_discard_prealloc(&th, inode); 98 #endif 99 err = journal_end(&th); 100 101 /* copy back the error code from journal_begin */ 102 if (!err) 103 err = jbegin_failure; 104 105 if (!err && 106 (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) && 107 tail_has_to_be_packed(inode)) { 108 109 /* 110 * if regular file is released by last holder and it has been 111 * appended (we append by unformatted node only) or its direct 112 * item(s) had to be converted, then it may have to be 113 * indirect2direct converted 114 */ 115 err = reiserfs_truncate_file(inode, 0); 116 } 117 out: 118 reiserfs_write_unlock(inode->i_sb); 119 mutex_unlock(&REISERFS_I(inode)->tailpack); 120 return err; 121 } 122 123 static int reiserfs_file_open(struct inode *inode, struct file *file) 124 { 125 int err = dquot_file_open(inode, file); 126 127 /* somebody might be tailpacking on final close; wait for it */ 128 if (!atomic_inc_not_zero(&REISERFS_I(inode)->openers)) { 129 mutex_lock(&REISERFS_I(inode)->tailpack); 130 atomic_inc(&REISERFS_I(inode)->openers); 131 mutex_unlock(&REISERFS_I(inode)->tailpack); 132 } 133 return err; 134 } 135 136 void reiserfs_vfs_truncate_file(struct inode *inode) 137 { 138 mutex_lock(&REISERFS_I(inode)->tailpack); 139 reiserfs_truncate_file(inode, 1); 140 mutex_unlock(&REISERFS_I(inode)->tailpack); 141 } 142 143 /* Sync a reiserfs file. */ 144 145 /* 146 * FIXME: sync_mapping_buffers() never has anything to sync. Can 147 * be removed... 148 */ 149 150 static int reiserfs_sync_file(struct file *filp, loff_t start, loff_t end, 151 int datasync) 152 { 153 struct inode *inode = filp->f_mapping->host; 154 int err; 155 int barrier_done; 156 157 err = file_write_and_wait_range(filp, start, end); 158 if (err) 159 return err; 160 161 inode_lock(inode); 162 BUG_ON(!S_ISREG(inode->i_mode)); 163 err = sync_mapping_buffers(inode->i_mapping); 164 reiserfs_write_lock(inode->i_sb); 165 barrier_done = reiserfs_commit_for_inode(inode); 166 reiserfs_write_unlock(inode->i_sb); 167 if (barrier_done != 1 && reiserfs_barrier_flush(inode->i_sb)) 168 blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); 169 inode_unlock(inode); 170 if (barrier_done < 0) 171 return barrier_done; 172 return (err < 0) ? -EIO : 0; 173 } 174 175 /* taken fs/buffer.c:__block_commit_write */ 176 int reiserfs_commit_page(struct inode *inode, struct page *page, 177 unsigned from, unsigned to) 178 { 179 unsigned block_start, block_end; 180 int partial = 0; 181 unsigned blocksize; 182 struct buffer_head *bh, *head; 183 unsigned long i_size_index = inode->i_size >> PAGE_SHIFT; 184 int new; 185 int logit = reiserfs_file_data_log(inode); 186 struct super_block *s = inode->i_sb; 187 int bh_per_page = PAGE_SIZE / s->s_blocksize; 188 struct reiserfs_transaction_handle th; 189 int ret = 0; 190 191 th.t_trans_id = 0; 192 blocksize = i_blocksize(inode); 193 194 if (logit) { 195 reiserfs_write_lock(s); 196 ret = journal_begin(&th, s, bh_per_page + 1); 197 if (ret) 198 goto drop_write_lock; 199 reiserfs_update_inode_transaction(inode); 200 } 201 for (bh = head = page_buffers(page), block_start = 0; 202 bh != head || !block_start; 203 block_start = block_end, bh = bh->b_this_page) { 204 205 new = buffer_new(bh); 206 clear_buffer_new(bh); 207 block_end = block_start + blocksize; 208 if (block_end <= from || block_start >= to) { 209 if (!buffer_uptodate(bh)) 210 partial = 1; 211 } else { 212 set_buffer_uptodate(bh); 213 if (logit) { 214 reiserfs_prepare_for_journal(s, bh, 1); 215 journal_mark_dirty(&th, bh); 216 } else if (!buffer_dirty(bh)) { 217 mark_buffer_dirty(bh); 218 /* 219 * do data=ordered on any page past the end 220 * of file and any buffer marked BH_New. 221 */ 222 if (reiserfs_data_ordered(inode->i_sb) && 223 (new || page->index >= i_size_index)) { 224 reiserfs_add_ordered_list(inode, bh); 225 } 226 } 227 } 228 } 229 if (logit) { 230 ret = journal_end(&th); 231 drop_write_lock: 232 reiserfs_write_unlock(s); 233 } 234 /* 235 * If this is a partial write which happened to make all buffers 236 * uptodate then we can optimize away a bogus readpage() for 237 * the next read(). Here we 'discover' whether the page went 238 * uptodate as a result of this (potentially partial) write. 239 */ 240 if (!partial) 241 SetPageUptodate(page); 242 return ret; 243 } 244 245 const struct file_operations reiserfs_file_operations = { 246 .unlocked_ioctl = reiserfs_ioctl, 247 #ifdef CONFIG_COMPAT 248 .compat_ioctl = reiserfs_compat_ioctl, 249 #endif 250 .mmap = generic_file_mmap, 251 .open = reiserfs_file_open, 252 .release = reiserfs_file_release, 253 .fsync = reiserfs_sync_file, 254 .read_iter = generic_file_read_iter, 255 .write_iter = generic_file_write_iter, 256 .splice_read = generic_file_splice_read, 257 .splice_write = iter_file_splice_write, 258 .llseek = generic_file_llseek, 259 }; 260 261 const struct inode_operations reiserfs_file_inode_operations = { 262 .setattr = reiserfs_setattr, 263 .listxattr = reiserfs_listxattr, 264 .permission = reiserfs_permission, 265 .get_acl = reiserfs_get_acl, 266 .set_acl = reiserfs_set_acl, 267 }; 268