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