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 
13 #define BLOCKS(size) (((size) + 511) >> 9)
14 
hpfs_file_release(struct inode * inode,struct file * file)15 static int hpfs_file_release(struct inode *inode, struct file *file)
16 {
17 	hpfs_lock(inode->i_sb);
18 	hpfs_write_if_changed(inode);
19 	hpfs_unlock(inode->i_sb);
20 	return 0;
21 }
22 
hpfs_file_fsync(struct file * file,loff_t start,loff_t end,int datasync)23 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
24 {
25 	struct inode *inode = file->f_mapping->host;
26 	int ret;
27 
28 	ret = file_write_and_wait_range(file, start, end);
29 	if (ret)
30 		return ret;
31 	return sync_blockdev(inode->i_sb->s_bdev);
32 }
33 
34 /*
35  * generic_file_read often calls bmap with non-existing sector,
36  * so we must ignore such errors.
37  */
38 
hpfs_bmap(struct inode * inode,unsigned file_secno,unsigned * n_secs)39 static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
40 {
41 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
42 	unsigned n, disk_secno;
43 	struct fnode *fnode;
44 	struct buffer_head *bh;
45 	if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
46 	n = file_secno - hpfs_inode->i_file_sec;
47 	if (n < hpfs_inode->i_n_secs) {
48 		*n_secs = hpfs_inode->i_n_secs - n;
49 		return hpfs_inode->i_disk_sec + n;
50 	}
51 	if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
52 	disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
53 	if (disk_secno == -1) return 0;
54 	if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
55 	n = file_secno - hpfs_inode->i_file_sec;
56 	if (n < hpfs_inode->i_n_secs) {
57 		*n_secs = hpfs_inode->i_n_secs - n;
58 		return hpfs_inode->i_disk_sec + n;
59 	}
60 	*n_secs = 1;
61 	return disk_secno;
62 }
63 
hpfs_truncate(struct inode * i)64 void hpfs_truncate(struct inode *i)
65 {
66 	if (IS_IMMUTABLE(i)) return /*-EPERM*/;
67 	hpfs_lock_assert(i->i_sb);
68 
69 	hpfs_i(i)->i_n_secs = 0;
70 	i->i_blocks = 1 + ((i->i_size + 511) >> 9);
71 	hpfs_i(i)->mmu_private = i->i_size;
72 	hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
73 	hpfs_write_inode(i);
74 	hpfs_i(i)->i_n_secs = 0;
75 }
76 
hpfs_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)77 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
78 {
79 	int r;
80 	secno s;
81 	unsigned n_secs;
82 	hpfs_lock(inode->i_sb);
83 	s = hpfs_bmap(inode, iblock, &n_secs);
84 	if (s) {
85 		if (bh_result->b_size >> 9 < n_secs)
86 			n_secs = bh_result->b_size >> 9;
87 		n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs);
88 		if (unlikely(!n_secs)) {
89 			s = hpfs_search_hotfix_map(inode->i_sb, s);
90 			n_secs = 1;
91 		}
92 		map_bh(bh_result, inode->i_sb, s);
93 		bh_result->b_size = n_secs << 9;
94 		goto ret_0;
95 	}
96 	if (!create) goto ret_0;
97 	if (iblock<<9 != hpfs_i(inode)->mmu_private) {
98 		BUG();
99 		r = -EIO;
100 		goto ret_r;
101 	}
102 	if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
103 		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
104 		r = -ENOSPC;
105 		goto ret_r;
106 	}
107 	inode->i_blocks++;
108 	hpfs_i(inode)->mmu_private += 512;
109 	set_buffer_new(bh_result);
110 	map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s));
111 	ret_0:
112 	r = 0;
113 	ret_r:
114 	hpfs_unlock(inode->i_sb);
115 	return r;
116 }
117 
hpfs_readpage(struct file * file,struct page * page)118 static int hpfs_readpage(struct file *file, struct page *page)
119 {
120 	return mpage_readpage(page, hpfs_get_block);
121 }
122 
hpfs_writepage(struct page * page,struct writeback_control * wbc)123 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
124 {
125 	return block_write_full_page(page, hpfs_get_block, wbc);
126 }
127 
hpfs_readpages(struct file * file,struct address_space * mapping,struct list_head * pages,unsigned nr_pages)128 static int hpfs_readpages(struct file *file, struct address_space *mapping,
129 			  struct list_head *pages, unsigned nr_pages)
130 {
131 	return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
132 }
133 
hpfs_writepages(struct address_space * mapping,struct writeback_control * wbc)134 static int hpfs_writepages(struct address_space *mapping,
135 			   struct writeback_control *wbc)
136 {
137 	return mpage_writepages(mapping, wbc, hpfs_get_block);
138 }
139 
hpfs_write_failed(struct address_space * mapping,loff_t to)140 static void hpfs_write_failed(struct address_space *mapping, loff_t to)
141 {
142 	struct inode *inode = mapping->host;
143 
144 	hpfs_lock(inode->i_sb);
145 
146 	if (to > inode->i_size) {
147 		truncate_pagecache(inode, inode->i_size);
148 		hpfs_truncate(inode);
149 	}
150 
151 	hpfs_unlock(inode->i_sb);
152 }
153 
hpfs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)154 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
155 			loff_t pos, unsigned len, unsigned flags,
156 			struct page **pagep, void **fsdata)
157 {
158 	int ret;
159 
160 	*pagep = NULL;
161 	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
162 				hpfs_get_block,
163 				&hpfs_i(mapping->host)->mmu_private);
164 	if (unlikely(ret))
165 		hpfs_write_failed(mapping, pos + len);
166 
167 	return ret;
168 }
169 
hpfs_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * pagep,void * fsdata)170 static int hpfs_write_end(struct file *file, struct address_space *mapping,
171 			loff_t pos, unsigned len, unsigned copied,
172 			struct page *pagep, void *fsdata)
173 {
174 	struct inode *inode = mapping->host;
175 	int err;
176 	err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
177 	if (err < len)
178 		hpfs_write_failed(mapping, pos + len);
179 	if (!(err < 0)) {
180 		/* make sure we write it on close, if not earlier */
181 		hpfs_lock(inode->i_sb);
182 		hpfs_i(inode)->i_dirty = 1;
183 		hpfs_unlock(inode->i_sb);
184 	}
185 	return err;
186 }
187 
_hpfs_bmap(struct address_space * mapping,sector_t block)188 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
189 {
190 	return generic_block_bmap(mapping, block, hpfs_get_block);
191 }
192 
hpfs_fiemap(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 len)193 static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
194 {
195 	return generic_block_fiemap(inode, fieinfo, start, len, hpfs_get_block);
196 }
197 
198 const struct address_space_operations hpfs_aops = {
199 	.readpage = hpfs_readpage,
200 	.writepage = hpfs_writepage,
201 	.readpages = hpfs_readpages,
202 	.writepages = hpfs_writepages,
203 	.write_begin = hpfs_write_begin,
204 	.write_end = hpfs_write_end,
205 	.bmap = _hpfs_bmap
206 };
207 
208 const struct file_operations hpfs_file_ops =
209 {
210 	.llseek		= generic_file_llseek,
211 	.read_iter	= generic_file_read_iter,
212 	.write_iter	= generic_file_write_iter,
213 	.mmap		= generic_file_mmap,
214 	.release	= hpfs_file_release,
215 	.fsync		= hpfs_file_fsync,
216 	.splice_read	= generic_file_splice_read,
217 	.unlocked_ioctl	= hpfs_ioctl,
218 };
219 
220 const struct inode_operations hpfs_file_iops =
221 {
222 	.setattr	= hpfs_setattr,
223 	.fiemap		= hpfs_fiemap,
224 };
225