1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/hpfs/file.c |
4 | * |
5 | * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 |
6 | * |
7 | * file VFS functions |
8 | */ |
9 | |
10 | #include "hpfs_fn.h" |
11 | #include <linux/mpage.h> |
12 | #include <linux/iomap.h> |
13 | #include <linux/fiemap.h> |
14 | |
15 | #define BLOCKS(size) (((size) + 511) >> 9) |
16 | |
17 | static int hpfs_file_release(struct inode *inode, struct file *file) |
18 | { |
19 | hpfs_lock(s: inode->i_sb); |
20 | hpfs_write_if_changed(inode); |
21 | hpfs_unlock(s: inode->i_sb); |
22 | return 0; |
23 | } |
24 | |
25 | int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
26 | { |
27 | struct inode *inode = file->f_mapping->host; |
28 | int ret; |
29 | |
30 | ret = file_write_and_wait_range(file, start, end); |
31 | if (ret) |
32 | return ret; |
33 | return sync_blockdev(bdev: inode->i_sb->s_bdev); |
34 | } |
35 | |
36 | /* |
37 | * generic_file_read often calls bmap with non-existing sector, |
38 | * so we must ignore such errors. |
39 | */ |
40 | |
41 | static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs) |
42 | { |
43 | struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); |
44 | unsigned n, disk_secno; |
45 | struct fnode *fnode; |
46 | struct buffer_head *bh; |
47 | if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; |
48 | n = file_secno - hpfs_inode->i_file_sec; |
49 | if (n < hpfs_inode->i_n_secs) { |
50 | *n_secs = hpfs_inode->i_n_secs - n; |
51 | return hpfs_inode->i_disk_sec + n; |
52 | } |
53 | if (!(fnode = hpfs_map_fnode(s: inode->i_sb, inode->i_ino, &bh))) return 0; |
54 | disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); |
55 | if (disk_secno == -1) return 0; |
56 | if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap" )) return 0; |
57 | n = file_secno - hpfs_inode->i_file_sec; |
58 | if (n < hpfs_inode->i_n_secs) { |
59 | *n_secs = hpfs_inode->i_n_secs - n; |
60 | return hpfs_inode->i_disk_sec + n; |
61 | } |
62 | *n_secs = 1; |
63 | return disk_secno; |
64 | } |
65 | |
66 | void hpfs_truncate(struct inode *i) |
67 | { |
68 | if (IS_IMMUTABLE(i)) return /*-EPERM*/; |
69 | hpfs_lock_assert(s: i->i_sb); |
70 | |
71 | hpfs_i(inode: i)->i_n_secs = 0; |
72 | i->i_blocks = 1 + ((i->i_size + 511) >> 9); |
73 | hpfs_i(inode: i)->mmu_private = i->i_size; |
74 | hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); |
75 | hpfs_write_inode(i); |
76 | hpfs_i(inode: i)->i_n_secs = 0; |
77 | } |
78 | |
79 | static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) |
80 | { |
81 | int r; |
82 | secno s; |
83 | unsigned n_secs; |
84 | hpfs_lock(s: inode->i_sb); |
85 | s = hpfs_bmap(inode, file_secno: iblock, n_secs: &n_secs); |
86 | if (s) { |
87 | if (bh_result->b_size >> 9 < n_secs) |
88 | n_secs = bh_result->b_size >> 9; |
89 | n_secs = hpfs_search_hotfix_map_for_range(s: inode->i_sb, sec: s, n: n_secs); |
90 | if (unlikely(!n_secs)) { |
91 | s = hpfs_search_hotfix_map(s: inode->i_sb, sec: s); |
92 | n_secs = 1; |
93 | } |
94 | map_bh(bh: bh_result, sb: inode->i_sb, block: s); |
95 | bh_result->b_size = n_secs << 9; |
96 | goto ret_0; |
97 | } |
98 | if (!create) goto ret_0; |
99 | if (iblock<<9 != hpfs_i(inode)->mmu_private) { |
100 | BUG(); |
101 | r = -EIO; |
102 | goto ret_r; |
103 | } |
104 | if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { |
105 | hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); |
106 | r = -ENOSPC; |
107 | goto ret_r; |
108 | } |
109 | inode->i_blocks++; |
110 | hpfs_i(inode)->mmu_private += 512; |
111 | set_buffer_new(bh_result); |
112 | map_bh(bh: bh_result, sb: inode->i_sb, block: hpfs_search_hotfix_map(s: inode->i_sb, sec: s)); |
113 | ret_0: |
114 | r = 0; |
115 | ret_r: |
116 | hpfs_unlock(s: inode->i_sb); |
117 | return r; |
118 | } |
119 | |
120 | static int hpfs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, |
121 | unsigned flags, struct iomap *iomap, struct iomap *srcmap) |
122 | { |
123 | struct super_block *sb = inode->i_sb; |
124 | unsigned int blkbits = inode->i_blkbits; |
125 | unsigned int n_secs; |
126 | secno s; |
127 | |
128 | if (WARN_ON_ONCE(flags & (IOMAP_WRITE | IOMAP_ZERO))) |
129 | return -EINVAL; |
130 | |
131 | iomap->bdev = inode->i_sb->s_bdev; |
132 | iomap->offset = offset; |
133 | |
134 | hpfs_lock(s: sb); |
135 | s = hpfs_bmap(inode, file_secno: offset >> blkbits, n_secs: &n_secs); |
136 | if (s) { |
137 | n_secs = hpfs_search_hotfix_map_for_range(s: sb, sec: s, |
138 | min_t(loff_t, n_secs, length)); |
139 | if (unlikely(!n_secs)) { |
140 | s = hpfs_search_hotfix_map(s: sb, sec: s); |
141 | n_secs = 1; |
142 | } |
143 | iomap->type = IOMAP_MAPPED; |
144 | iomap->flags = IOMAP_F_MERGED; |
145 | iomap->addr = (u64)s << blkbits; |
146 | iomap->length = (u64)n_secs << blkbits; |
147 | } else { |
148 | iomap->type = IOMAP_HOLE; |
149 | iomap->addr = IOMAP_NULL_ADDR; |
150 | iomap->length = 1 << blkbits; |
151 | } |
152 | |
153 | hpfs_unlock(s: sb); |
154 | return 0; |
155 | } |
156 | |
157 | static const struct iomap_ops hpfs_iomap_ops = { |
158 | .iomap_begin = hpfs_iomap_begin, |
159 | }; |
160 | |
161 | static int hpfs_read_folio(struct file *file, struct folio *folio) |
162 | { |
163 | return mpage_read_folio(folio, get_block: hpfs_get_block); |
164 | } |
165 | |
166 | static void hpfs_readahead(struct readahead_control *rac) |
167 | { |
168 | mpage_readahead(rac, get_block: hpfs_get_block); |
169 | } |
170 | |
171 | static int hpfs_writepages(struct address_space *mapping, |
172 | struct writeback_control *wbc) |
173 | { |
174 | return mpage_writepages(mapping, wbc, get_block: hpfs_get_block); |
175 | } |
176 | |
177 | static void hpfs_write_failed(struct address_space *mapping, loff_t to) |
178 | { |
179 | struct inode *inode = mapping->host; |
180 | |
181 | hpfs_lock(s: inode->i_sb); |
182 | |
183 | if (to > inode->i_size) { |
184 | truncate_pagecache(inode, new: inode->i_size); |
185 | hpfs_truncate(i: inode); |
186 | } |
187 | |
188 | hpfs_unlock(s: inode->i_sb); |
189 | } |
190 | |
191 | static int hpfs_write_begin(struct file *file, struct address_space *mapping, |
192 | loff_t pos, unsigned len, |
193 | struct page **pagep, void **fsdata) |
194 | { |
195 | int ret; |
196 | |
197 | *pagep = NULL; |
198 | ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, |
199 | hpfs_get_block, |
200 | &hpfs_i(inode: mapping->host)->mmu_private); |
201 | if (unlikely(ret)) |
202 | hpfs_write_failed(mapping, to: pos + len); |
203 | |
204 | return ret; |
205 | } |
206 | |
207 | static int hpfs_write_end(struct file *file, struct address_space *mapping, |
208 | loff_t pos, unsigned len, unsigned copied, |
209 | struct page *pagep, void *fsdata) |
210 | { |
211 | struct inode *inode = mapping->host; |
212 | int err; |
213 | err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); |
214 | if (err < len) |
215 | hpfs_write_failed(mapping, to: pos + len); |
216 | if (!(err < 0)) { |
217 | /* make sure we write it on close, if not earlier */ |
218 | hpfs_lock(s: inode->i_sb); |
219 | hpfs_i(inode)->i_dirty = 1; |
220 | hpfs_unlock(s: inode->i_sb); |
221 | } |
222 | return err; |
223 | } |
224 | |
225 | static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) |
226 | { |
227 | return generic_block_bmap(mapping, block, hpfs_get_block); |
228 | } |
229 | |
230 | static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) |
231 | { |
232 | int ret; |
233 | |
234 | inode_lock(inode); |
235 | len = min_t(u64, len, i_size_read(inode)); |
236 | ret = iomap_fiemap(inode, fieinfo, start, len, ops: &hpfs_iomap_ops); |
237 | inode_unlock(inode); |
238 | |
239 | return ret; |
240 | } |
241 | |
242 | const struct address_space_operations hpfs_aops = { |
243 | .dirty_folio = block_dirty_folio, |
244 | .invalidate_folio = block_invalidate_folio, |
245 | .read_folio = hpfs_read_folio, |
246 | .readahead = hpfs_readahead, |
247 | .writepages = hpfs_writepages, |
248 | .write_begin = hpfs_write_begin, |
249 | .write_end = hpfs_write_end, |
250 | .bmap = _hpfs_bmap, |
251 | .migrate_folio = buffer_migrate_folio, |
252 | }; |
253 | |
254 | const struct file_operations hpfs_file_ops = |
255 | { |
256 | .llseek = generic_file_llseek, |
257 | .read_iter = generic_file_read_iter, |
258 | .write_iter = generic_file_write_iter, |
259 | .mmap = generic_file_mmap, |
260 | .release = hpfs_file_release, |
261 | .fsync = hpfs_file_fsync, |
262 | .splice_read = filemap_splice_read, |
263 | .unlocked_ioctl = hpfs_ioctl, |
264 | .compat_ioctl = compat_ptr_ioctl, |
265 | }; |
266 | |
267 | const struct inode_operations hpfs_file_iops = |
268 | { |
269 | .setattr = hpfs_setattr, |
270 | .fiemap = hpfs_fiemap, |
271 | }; |
272 | |