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 we are the last writer on the inode, drop the block reservation */
  37         if ((filp->f_mode & FMODE_WRITE) &&
  38                         (atomic_read(&inode->i_writecount) == 1))
  39                 ext3_discard_reservation(inode);
  40         if (is_dx(inode) && filp->private_data)
  41                 ext3_htree_free_dir_info(filp->private_data);
  42
  43         return 0;
  44 }
  45
  46 static ssize_t
  47 ext3_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
  48 {
  49         struct file *file = iocb->ki_filp;
  50         struct inode *inode = file->f_dentry->d_inode;
  51         ssize_t ret;
  52         int err;
  53
  54         ret = generic_file_aio_write(iocb, buf, count, pos);
  55
  56         /*
  57          * Skip flushing if there was an error, or if nothing was written.
  58          */
  59         if (ret <= 0)
  60                 return ret;
  61
  62         /*
  63          * If the inode is IS_SYNC, or is O_SYNC and we are doing data
  64          * journalling then we need to make sure that we force the transaction
  65          * to disk to keep all metadata uptodate synchronously.
  66          */
  67         if (file->f_flags & O_SYNC) {
  68                 /*
  69                  * If we are non-data-journaled, then the dirty data has
  70                  * already been flushed to backing store by generic_osync_inode,
  71                  * and the inode has been flushed too if there have been any
  72                  * modifications other than mere timestamp updates.
  73                  *
  74                  * Open question --- do we care about flushing timestamps too
  75                  * if the inode is IS_SYNC?
  76                  */
  77                 if (!ext3_should_journal_data(inode))
  78                         return ret;
  79
  80                 goto force_commit;
  81         }
  82
  83         /*
  84          * So we know that there has been no forced data flush.  If the inode
  85          * is marked IS_SYNC, we need to force one ourselves.
  86          */
  87         if (!IS_SYNC(inode))
  88                 return ret;
  89
  90         /*
  91          * Open question #2 --- should we force data to disk here too?  If we
  92          * don't, the only impact is that data=writeback filesystems won't
  93          * flush data to disk automatically on IS_SYNC, only metadata (but
  94          * historically, that is what ext2 has done.)
  95          */
  96
  97 force_commit:
  98         err = ext3_force_commit(inode->i_sb);
  99         if (err)
 100                 return err;
 101         return ret;
 102 }
 103
 104 struct file_operations ext3_file_operations = {
 105         .llseek         = generic_file_llseek,
 106         .read           = do_sync_read,
 107         .write          = do_sync_write,
 108         .aio_read       = generic_file_aio_read,
 109         .aio_write      = ext3_file_write,
 110         .readv          = generic_file_readv,
 111         .writev         = generic_file_writev,
 112         .ioctl          = ext3_ioctl,
 113         .mmap           = generic_file_mmap,
 114         .open           = generic_file_open,
 115         .release        = ext3_release_file,
 116         .fsync          = ext3_sync_file,
 117         .sendfile       = generic_file_sendfile,
 118 };
 119
 120 struct inode_operations ext3_file_inode_operations = {
 121         .truncate       = ext3_truncate,
 122         .setattr        = ext3_setattr,
 123 #ifdef CONFIG_EXT3_FS_XATTR
 124         .setxattr       = generic_setxattr,
 125         .getxattr       = generic_getxattr,
 126         .listxattr      = ext3_listxattr,
 127         .removexattr    = generic_removexattr,
 128 #endif
 129         .permission     = ext3_permission,
 130 };
 131