1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * NILFS regular file handling primitives including fsync().
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Amagai Yoshiji and Ryusuke Konishi.
8 */
9
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/writeback.h>
13 #include "nilfs.h"
14 #include "segment.h"
15
16 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
17 {
18 /*
19 * Called from fsync() system call
20 * This is the only entry point that can catch write and synch
21 * timing for both data blocks and intermediate blocks.
22 *
23 * This function should be implemented when the writeback function
24 * will be implemented.
25 */
26 struct the_nilfs *nilfs;
27 struct inode *inode = file->f_mapping->host;
28 int err = 0;
29
30 if (nilfs_inode_dirty(inode)) {
31 if (datasync)
32 err = nilfs_construct_dsync_segment(inode->i_sb, inode,
33 start, end);
34 else
35 err = nilfs_construct_segment(inode->i_sb);
36 }
37
38 nilfs = inode->i_sb->s_fs_info;
39 if (!err)
40 err = nilfs_flush_device(nilfs);
41
42 return err;
43 }
44
45 static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf)
46 {
47 struct vm_area_struct *vma = vmf->vma;
48 struct folio *folio = page_folio(vmf->page);
49 struct inode *inode = file_inode(vma->vm_file);
50 struct nilfs_transaction_info ti;
51 struct buffer_head *bh, *head;
52 int ret = 0;
53
54 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
55 return VM_FAULT_SIGBUS; /* -ENOSPC */
56
57 sb_start_pagefault(inode->i_sb);
58 folio_lock(folio);
59 if (folio->mapping != inode->i_mapping ||
60 folio_pos(folio) >= i_size_read(inode) ||
61 !folio_test_uptodate(folio)) {
62 folio_unlock(folio);
63 ret = -EFAULT; /* make the VM retry the fault */
64 goto out;
65 }
66
67 /*
68 * check to see if the folio is mapped already (no holes)
69 */
70 if (folio_test_mappedtodisk(folio))
71 goto mapped;
72
73 head = folio_buffers(folio);
74 if (head) {
75 int fully_mapped = 1;
76
77 bh = head;
78 do {
79 if (!buffer_mapped(bh)) {
80 fully_mapped = 0;
81 break;
82 }
83 } while (bh = bh->b_this_page, bh != head);
84
85 if (fully_mapped) {
86 folio_set_mappedtodisk(folio);
87 goto mapped;
88 }
89 }
90 folio_unlock(folio);
91
92 /*
93 * fill hole blocks
94 */
95 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
96 /* never returns -ENOMEM, but may return -ENOSPC */
97 if (unlikely(ret))
98 goto out;
99
100 file_update_time(vma->vm_file);
101 ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
102 if (ret) {
103 nilfs_transaction_abort(inode->i_sb);
104 goto out;
105 }
106 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
107 nilfs_transaction_commit(inode->i_sb);
108
109 mapped:
110 /*
111 * Since checksumming including data blocks is performed to determine
112 * the validity of the log to be written and used for recovery, it is
113 * necessary to wait for writeback to finish here, regardless of the
114 * stable write requirement of the backing device.
115 */
116 folio_wait_writeback(folio);
117 out:
118 sb_end_pagefault(inode->i_sb);
119 return vmf_fs_error(ret);
120 }
121
122 static const struct vm_operations_struct nilfs_file_vm_ops = {
123 .fault = filemap_fault,
124 .map_pages = filemap_map_pages,
125 .page_mkwrite = nilfs_page_mkwrite,
126 };
127
128 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
129 {
130 file_accessed(file);
131 vma->vm_ops = &nilfs_file_vm_ops;
132 return 0;
133 }
134
135 /*
136 * We have mostly NULL's here: the current defaults are ok for
137 * the nilfs filesystem.
138 */
139 const struct file_operations nilfs_file_operations = {
140 .llseek = generic_file_llseek,
141 .read_iter = generic_file_read_iter,
142 .write_iter = generic_file_write_iter,
143 .unlocked_ioctl = nilfs_ioctl,
144 #ifdef CONFIG_COMPAT
145 .compat_ioctl = nilfs_compat_ioctl,
146 #endif /* CONFIG_COMPAT */
147 .mmap = nilfs_file_mmap,
148 .open = generic_file_open,
149 /* .release = nilfs_release_file, */
150 .fsync = nilfs_sync_file,
151 .splice_read = filemap_splice_read,
152 .splice_write = iter_file_splice_write,
153 };
154
155 const struct inode_operations nilfs_file_inode_operations = {
156 .setattr = nilfs_setattr,
157 .permission = nilfs_permission,
158 .fiemap = nilfs_fiemap,
159 .fileattr_get = nilfs_fileattr_get,
160 .fileattr_set = nilfs_fileattr_set,
161 };
162
163 /* end of file */
164
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