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