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
nilfs_sync_file(struct file * file,int datasync)30 int nilfs_sync_file(struct file *file, 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 if (!nilfs_inode_dirty(inode))
44 return 0;
45
46 if (datasync)
47 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 0,
48 LLONG_MAX);
49 else
50 err = nilfs_construct_segment(inode->i_sb);
51
52 return err;
53 }
54
nilfs_page_mkwrite(struct vm_area_struct * vma,struct vm_fault * vmf)55 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
56 {
57 struct page *page = vmf->page;
58 struct inode *inode = vma->vm_file->f_dentry->d_inode;
59 struct nilfs_transaction_info ti;
60 int ret;
61
62 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
63 return VM_FAULT_SIGBUS; /* -ENOSPC */
64
65 lock_page(page);
66 if (page->mapping != inode->i_mapping ||
67 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
68 unlock_page(page);
69 return VM_FAULT_NOPAGE; /* make the VM retry the fault */
70 }
71
72 /*
73 * check to see if the page is mapped already (no holes)
74 */
75 if (PageMappedToDisk(page))
76 goto mapped;
77
78 if (page_has_buffers(page)) {
79 struct buffer_head *bh, *head;
80 int fully_mapped = 1;
81
82 bh = head = page_buffers(page);
83 do {
84 if (!buffer_mapped(bh)) {
85 fully_mapped = 0;
86 break;
87 }
88 } while (bh = bh->b_this_page, bh != head);
89
90 if (fully_mapped) {
91 SetPageMappedToDisk(page);
92 goto mapped;
93 }
94 }
95 unlock_page(page);
96
97 /*
98 * fill hole blocks
99 */
100 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
101 /* never returns -ENOMEM, but may return -ENOSPC */
102 if (unlikely(ret))
103 return VM_FAULT_SIGBUS;
104
105 ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
106 if (ret != VM_FAULT_LOCKED) {
107 nilfs_transaction_abort(inode->i_sb);
108 return ret;
109 }
110 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
111 nilfs_transaction_commit(inode->i_sb);
112
113 mapped:
114 SetPageChecked(page);
115 wait_on_page_writeback(page);
116 return VM_FAULT_LOCKED;
117 }
118
119 static const struct vm_operations_struct nilfs_file_vm_ops = {
120 .fault = filemap_fault,
121 .page_mkwrite = nilfs_page_mkwrite,
122 };
123
nilfs_file_mmap(struct file * file,struct vm_area_struct * vma)124 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
125 {
126 file_accessed(file);
127 vma->vm_ops = &nilfs_file_vm_ops;
128 vma->vm_flags |= VM_CAN_NONLINEAR;
129 return 0;
130 }
131
132 /*
133 * We have mostly NULL's here: the current defaults are ok for
134 * the nilfs filesystem.
135 */
136 const struct file_operations nilfs_file_operations = {
137 .llseek = generic_file_llseek,
138 .read = do_sync_read,
139 .write = do_sync_write,
140 .aio_read = generic_file_aio_read,
141 .aio_write = generic_file_aio_write,
142 .unlocked_ioctl = nilfs_ioctl,
143 #ifdef CONFIG_COMPAT
144 .compat_ioctl = nilfs_compat_ioctl,
145 #endif /* CONFIG_COMPAT */
146 .mmap = nilfs_file_mmap,
147 .open = generic_file_open,
148 /* .release = nilfs_release_file, */
149 .fsync = nilfs_sync_file,
150 .splice_read = generic_file_splice_read,
151 };
152
153 const struct inode_operations nilfs_file_inode_operations = {
154 .truncate = nilfs_truncate,
155 .setattr = nilfs_setattr,
156 .permission = nilfs_permission,
157 .fiemap = nilfs_fiemap,
158 };
159
160 /* end of file */
161