fanotify: fix missing break
[linux-2.6.git] / fs / nilfs2 / file.c
1 /*
2  * file.c - NILFS regular file handling primitives including fsync().
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Amagai Yoshiji <amagai@osrg.net>,
21  *            Ryusuke Konishi <ryusuke@osrg.net>
22  */
23
24 #include <linux/fs.h>
25 #include <linux/mm.h>
26 #include <linux/writeback.h>
27 #include "nilfs.h"
28 #include "segment.h"
29
30 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
31 {
32         /*
33          * Called from fsync() system call
34          * This is the only entry point that can catch write and synch
35          * timing for both data blocks and intermediate blocks.
36          *
37          * This function should be implemented when the writeback function
38          * will be implemented.
39          */
40         struct inode *inode = file->f_mapping->host;
41         int err;
42
43         err = filemap_write_and_wait_range(inode->i_mapping, start, end);
44         if (err)
45                 return err;
46         mutex_lock(&inode->i_mutex);
47
48         if (!nilfs_inode_dirty(inode)) {
49                 mutex_unlock(&inode->i_mutex);
50                 return 0;
51         }
52
53         if (datasync)
54                 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 0,
55                                                     LLONG_MAX);
56         else
57                 err = nilfs_construct_segment(inode->i_sb);
58
59         mutex_unlock(&inode->i_mutex);
60         return err;
61 }
62
63 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
64 {
65         struct page *page = vmf->page;
66         struct inode *inode = vma->vm_file->f_dentry->d_inode;
67         struct nilfs_transaction_info ti;
68         int ret;
69
70         if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
71                 return VM_FAULT_SIGBUS; /* -ENOSPC */
72
73         lock_page(page);
74         if (page->mapping != inode->i_mapping ||
75             page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
76                 unlock_page(page);
77                 return VM_FAULT_NOPAGE; /* make the VM retry the fault */
78         }
79
80         /*
81          * check to see if the page is mapped already (no holes)
82          */
83         if (PageMappedToDisk(page))
84                 goto mapped;
85
86         if (page_has_buffers(page)) {
87                 struct buffer_head *bh, *head;
88                 int fully_mapped = 1;
89
90                 bh = head = page_buffers(page);
91                 do {
92                         if (!buffer_mapped(bh)) {
93                                 fully_mapped = 0;
94                                 break;
95                         }
96                 } while (bh = bh->b_this_page, bh != head);
97
98                 if (fully_mapped) {
99                         SetPageMappedToDisk(page);
100                         goto mapped;
101                 }
102         }
103         unlock_page(page);
104
105         /*
106          * fill hole blocks
107          */
108         ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
109         /* never returns -ENOMEM, but may return -ENOSPC */
110         if (unlikely(ret))
111                 return VM_FAULT_SIGBUS;
112
113         ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
114         if (ret != VM_FAULT_LOCKED) {
115                 nilfs_transaction_abort(inode->i_sb);
116                 return ret;
117         }
118         nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
119         nilfs_transaction_commit(inode->i_sb);
120
121  mapped:
122         wait_on_page_writeback(page);
123         return VM_FAULT_LOCKED;
124 }
125
126 static const struct vm_operations_struct nilfs_file_vm_ops = {
127         .fault          = filemap_fault,
128         .page_mkwrite   = nilfs_page_mkwrite,
129 };
130
131 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
132 {
133         file_accessed(file);
134         vma->vm_ops = &nilfs_file_vm_ops;
135         vma->vm_flags |= VM_CAN_NONLINEAR;
136         return 0;
137 }
138
139 /*
140  * We have mostly NULL's here: the current defaults are ok for
141  * the nilfs filesystem.
142  */
143 const struct file_operations nilfs_file_operations = {
144         .llseek         = generic_file_llseek,
145         .read           = do_sync_read,
146         .write          = do_sync_write,
147         .aio_read       = generic_file_aio_read,
148         .aio_write      = generic_file_aio_write,
149         .unlocked_ioctl = nilfs_ioctl,
150 #ifdef CONFIG_COMPAT
151         .compat_ioctl   = nilfs_compat_ioctl,
152 #endif  /* CONFIG_COMPAT */
153         .mmap           = nilfs_file_mmap,
154         .open           = generic_file_open,
155         /* .release     = nilfs_release_file, */
156         .fsync          = nilfs_sync_file,
157         .splice_read    = generic_file_splice_read,
158 };
159
160 const struct inode_operations nilfs_file_inode_operations = {
161         .truncate       = nilfs_truncate,
162         .setattr        = nilfs_setattr,
163         .permission     = nilfs_permission,
164         .fiemap         = nilfs_fiemap,
165 };
166
167 /* end of file */