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(f: 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(sb: 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(file: vma->vm_file); |
101 | ret = block_page_mkwrite(vma, vmf, get_block: nilfs_get_block); |
102 | if (ret) { |
103 | nilfs_transaction_abort(inode->i_sb); |
104 | goto out; |
105 | } |
106 | nilfs_set_file_dirty(inode, nr_dirty: 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(sb: inode->i_sb); |
119 | return vmf_fs_error(err: 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 | |