fs/ext3/file.c

   1 /*
   2  *  linux/fs/ext3/file.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/file.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext3 fs regular file handling primitives
  16  *
  17  *  64-bit file support on 64-bit platforms by Jakub Jelinek
  18  *      (jj@sunsite.ms.mff.cuni.cz)
  19  */
  20
  21 #include <linux/time.h>
  22 #include <linux/fs.h>
  23 #include <linux/jbd.h>
  24 #include <linux/ext3_fs.h>
  25 #include <linux/ext3_jbd.h>
  26 #include "xattr.h"
  27 #include "acl.h"
  28
  29 /*
  30  * Called when an inode is released. Note that this is different
  31  * from ext3_file_open: open gets called at every open, but release
  32  * gets called only when /all/ the files are closed.
  33  */
  34 static int ext3_release_file (struct inode * inode, struct file * filp)
  35 {
  36         if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) {
  37                 filemap_flush(inode->i_mapping);
  38                 EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE;
  39         }
  40         /* if we are the last writer on the inode, drop the block reservation */
  41         if ((filp->f_mode & FMODE_WRITE) &&
  42                         (atomic_read(&inode->i_writecount) == 1))
  43         {
  44                 mutex_lock(&EXT3_I(inode)->truncate_mutex);
  45                 ext3_discard_reservation(inode);
  46                 mutex_unlock(&EXT3_I(inode)->truncate_mutex);
  47         }
  48         if (is_dx(inode) && filp->private_data)
  49                 ext3_htree_free_dir_info(filp->private_data);
  50
  51         return 0;
  52 }
  53
  54 static ssize_t
  55 ext3_file_write(struct kiocb *iocb, const struct iovec *iov,
  56                 unsigned long nr_segs, loff_t pos)
  57 {
  58         struct file *file = iocb->ki_filp;
  59         struct inode *inode = file->f_path.dentry->d_inode;
  60         ssize_t ret;
  61         int err;
  62
  63         ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
  64
  65         /*
  66          * Skip flushing if there was an error, or if nothing was written.
  67          */
  68         if (ret <= 0)
  69                 return ret;
  70
  71         /*
  72          * If the inode is IS_SYNC, or is O_SYNC and we are doing data
  73          * journalling then we need to make sure that we force the transaction
  74          * to disk to keep all metadata uptodate synchronously.
  75          */
  76         if (file->f_flags & O_SYNC) {
  77                 /*
  78                  * If we are non-data-journaled, then the dirty data has
  79                  * already been flushed to backing store by generic_osync_inode,
  80                  * and the inode has been flushed too if there have been any
  81                  * modifications other than mere timestamp updates.
  82                  *
  83                  * Open question --- do we care about flushing timestamps too
  84                  * if the inode is IS_SYNC?
  85                  */
  86                 if (!ext3_should_journal_data(inode))
  87                         return ret;
  88
  89                 goto force_commit;
  90         }
  91
  92         /*
  93          * So we know that there has been no forced data flush.  If the inode
  94          * is marked IS_SYNC, we need to force one ourselves.
  95          */
  96         if (!IS_SYNC(inode))
  97                 return ret;
  98
  99         /*
 100          * Open question #2 --- should we force data to disk here too?  If we
 101          * don't, the only impact is that data=writeback filesystems won't
 102          * flush data to disk automatically on IS_SYNC, only metadata (but
 103          * historically, that is what ext2 has done.)
 104          */
 105
 106 force_commit:
 107         err = ext3_force_commit(inode->i_sb);
 108         if (err)
 109                 return err;
 110         return ret;
 111 }
 112
 113 const struct file_operations ext3_file_operations = {
 114         .llseek         = generic_file_llseek,
 115         .read           = do_sync_read,
 116         .write          = do_sync_write,
 117         .aio_read       = generic_file_aio_read,
 118         .aio_write      = ext3_file_write,
 119         .unlocked_ioctl = ext3_ioctl,
 120 #ifdef CONFIG_COMPAT
 121         .compat_ioctl   = ext3_compat_ioctl,
 122 #endif
 123         .mmap           = generic_file_mmap,
 124         .open           = generic_file_open,
 125         .release        = ext3_release_file,
 126         .fsync          = ext3_sync_file,
 127         .splice_read    = generic_file_splice_read,
 128         .splice_write   = generic_file_splice_write,
 129 };
 130
 131 const struct inode_operations ext3_file_inode_operations = {
 132         .truncate       = ext3_truncate,
 133         .setattr        = ext3_setattr,
 134 #ifdef CONFIG_EXT3_FS_XATTR
 135         .setxattr       = generic_setxattr,
 136         .getxattr       = generic_getxattr,
 137         .listxattr      = ext3_listxattr,
 138         .removexattr    = generic_removexattr,
 139 #endif
 140         .permission     = ext3_permission,
 141         .fiemap         = ext3_fiemap,
 142 };
 143