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         {
  40                 mutex_lock(&EXT3_I(inode)->truncate_mutex);
  41                 ext3_discard_reservation(inode);
  42                 mutex_unlock(&EXT3_I(inode)->truncate_mutex);
  43         }
  44         if (is_dx(inode) && filp->private_data)
  45                 ext3_htree_free_dir_info(filp->private_data);
  46
  47         return 0;
  48 }
  49
  50 static ssize_t
  51 ext3_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
  52 {
  53         struct file *file = iocb->ki_filp;
  54         struct inode *inode = file->f_dentry->d_inode;
  55         ssize_t ret;
  56         int err;
  57
  58         ret = generic_file_aio_write(iocb, buf, count, pos);
  59
  60         /*
  61          * Skip flushing if there was an error, or if nothing was written.
  62          */
  63         if (ret <= 0)
  64                 return ret;
  65
  66         /*
  67          * If the inode is IS_SYNC, or is O_SYNC and we are doing data
  68          * journalling then we need to make sure that we force the transaction
  69          * to disk to keep all metadata uptodate synchronously.
  70          */
  71         if (file->f_flags & O_SYNC) {
  72                 /*
  73                  * If we are non-data-journaled, then the dirty data has
  74                  * already been flushed to backing store by generic_osync_inode,
  75                  * and the inode has been flushed too if there have been any
  76                  * modifications other than mere timestamp updates.
  77                  *
  78                  * Open question --- do we care about flushing timestamps too
  79                  * if the inode is IS_SYNC?
  80                  */
  81                 if (!ext3_should_journal_data(inode))
  82                         return ret;
  83
  84                 goto force_commit;
  85         }
  86
  87         /*
  88          * So we know that there has been no forced data flush.  If the inode
  89          * is marked IS_SYNC, we need to force one ourselves.
  90          */
  91         if (!IS_SYNC(inode))
  92                 return ret;
  93
  94         /*
  95          * Open question #2 --- should we force data to disk here too?  If we
  96          * don't, the only impact is that data=writeback filesystems won't
  97          * flush data to disk automatically on IS_SYNC, only metadata (but
  98          * historically, that is what ext2 has done.)
  99          */
 100
 101 force_commit:
 102         err = ext3_force_commit(inode->i_sb);
 103         if (err)
 104                 return err;
 105         return ret;
 106 }
 107
 108 struct file_operations ext3_file_operations = {
 109         .llseek         = generic_file_llseek,
 110         .read           = do_sync_read,
 111         .write          = do_sync_write,
 112         .aio_read       = generic_file_aio_read,
 113         .aio_write      = ext3_file_write,
 114         .readv          = generic_file_readv,
 115         .writev         = generic_file_writev,
 116         .ioctl          = ext3_ioctl,
 117         .mmap           = generic_file_mmap,
 118         .open           = generic_file_open,
 119         .release        = ext3_release_file,
 120         .fsync          = ext3_sync_file,
 121         .sendfile       = generic_file_sendfile,
 122 };
 123
 124 struct inode_operations ext3_file_inode_operations = {
 125         .truncate       = ext3_truncate,
 126         .setattr        = ext3_setattr,
 127 #ifdef CONFIG_EXT3_FS_XATTR
 128         .setxattr       = generic_setxattr,
 129         .getxattr       = generic_getxattr,
 130         .listxattr      = ext3_listxattr,
 131         .removexattr    = generic_removexattr,
 132 #endif
 133         .permission     = ext3_permission,
 134 };
 135