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/sched.h>
22 #include <linux/fs.h>
23 #include <linux/locks.h>
24 #include <linux/jbd.h>
25 #include <linux/ext3_fs.h>
26 #include <linux/ext3_jbd.h>
27 #include <linux/smp_lock.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 */
ext3_release_file(struct inode * inode,struct file * filp)34 static int ext3_release_file (struct inode * inode, struct file * filp)
35 {
36 if (filp->f_mode & FMODE_WRITE)
37 ext3_discard_prealloc (inode);
38 return 0;
39 }
40
41 /*
42 * Called when an inode is about to be opened.
43 * We use this to disallow opening RW large files on 32bit systems if
44 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
45 * on this flag in sys_open.
46 */
ext3_open_file(struct inode * inode,struct file * filp)47 static int ext3_open_file (struct inode * inode, struct file * filp)
48 {
49 if (!(filp->f_flags & O_LARGEFILE) &&
50 inode->i_size > 0x7FFFFFFFLL)
51 return -EFBIG;
52 return 0;
53 }
54
55 /*
56 * ext3_file_write().
57 *
58 * Most things are done in ext3_prepare_write() and ext3_commit_write().
59 */
60
61 static ssize_t
ext3_file_write(struct file * file,const char * buf,size_t count,loff_t * ppos)62 ext3_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
63 {
64 ssize_t ret;
65 int err;
66 struct inode *inode = file->f_dentry->d_inode;
67
68 ret = generic_file_write(file, buf, count, ppos);
69
70 /* Skip file flushing code if there was an error, or if nothing
71 was written. */
72 if (ret <= 0)
73 return ret;
74
75 /* If the inode is IS_SYNC, or is O_SYNC and we are doing
76 data-journaling, then we need to make sure that we force the
77 transaction to disk to keep all metadata uptodate
78 synchronously. */
79
80 if (file->f_flags & O_SYNC) {
81 /* If we are non-data-journaled, then the dirty data has
82 already been flushed to backing store by
83 generic_osync_inode, and the inode has been flushed
84 too if there have been any modifications other than
85 mere timestamp updates.
86
87 Open question --- do we care about flushing
88 timestamps too if the inode is IS_SYNC? */
89 if (!ext3_should_journal_data(inode))
90 return ret;
91
92 goto force_commit;
93 }
94
95 /* So we know that there has been no forced data flush. If the
96 inode is marked IS_SYNC, we need to force one ourselves. */
97 if (!IS_SYNC(inode))
98 return ret;
99
100 /* Open question #2 --- should we force data to disk here too?
101 If we don't, the only impact is that data=writeback
102 filesystems won't flush data to disk automatically on
103 IS_SYNC, only metadata (but historically, that is what ext2
104 has done.) */
105
106 force_commit:
107 err = ext3_force_commit(inode->i_sb);
108 if (err)
109 return err;
110 return ret;
111 }
112
113 struct file_operations ext3_file_operations = {
114 llseek: generic_file_llseek, /* BKL held */
115 read: generic_file_read, /* BKL not held. Don't need */
116 write: ext3_file_write, /* BKL not held. Don't need */
117 ioctl: ext3_ioctl, /* BKL held */
118 mmap: generic_file_mmap,
119 open: ext3_open_file, /* BKL not held. Don't need */
120 release: ext3_release_file, /* BKL not held. Don't need */
121 fsync: ext3_sync_file, /* BKL held */
122 };
123
124 struct inode_operations ext3_file_inode_operations = {
125 truncate: ext3_truncate, /* BKL held */
126 setattr: ext3_setattr, /* BKL held */
127 };
128
129