ia64/linux-2.6.18-xen.hg

view fs/ext3/file.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
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"
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);
47 return 0;
48 }
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;
58 ret = generic_file_aio_write(iocb, buf, count, pos);
60 /*
61 * Skip flushing if there was an error, or if nothing was written.
62 */
63 if (ret <= 0)
64 return ret;
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;
84 goto force_commit;
85 }
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;
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 */
101 force_commit:
102 err = ext3_force_commit(inode->i_sb);
103 if (err)
104 return err;
105 return ret;
106 }
108 const 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 .splice_read = generic_file_splice_read,
123 .splice_write = generic_file_splice_write,
124 };
126 struct inode_operations ext3_file_inode_operations = {
127 .truncate = ext3_truncate,
128 .setattr = ext3_setattr,
129 #ifdef CONFIG_EXT3_FS_XATTR
130 .setxattr = generic_setxattr,
131 .getxattr = generic_getxattr,
132 .listxattr = ext3_listxattr,
133 .removexattr = generic_removexattr,
134 #endif
135 .permission = ext3_permission,
136 };