fs/reiserfs/file.c

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