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(inode->i_sb); 20 hpfs_write_if_changed(inode); 21 hpfs_unlock(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(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(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(i->i_sb); 70 71 hpfs_i(i)->i_n_secs = 0; 72 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 73 hpfs_i(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(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(inode->i_sb); 85 s = hpfs_bmap(inode, iblock, &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(inode->i_sb, s, n_secs); 90 if (unlikely(!n_secs)) { 91 s = hpfs_search_hotfix_map(inode->i_sb, s); 92 n_secs = 1; 93 } 94 map_bh(bh_result, inode->i_sb, 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_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s)); 113 ret_0: 114 r = 0; 115 ret_r: 116 hpfs_unlock(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(sb); 135 s = hpfs_bmap(inode, offset >> blkbits, &n_secs); 136 if (s) { 137 n_secs = hpfs_search_hotfix_map_for_range(sb, s, 138 min_t(loff_t, n_secs, length)); 139 if (unlikely(!n_secs)) { 140 s = hpfs_search_hotfix_map(sb, 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(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_readpage(struct file *file, struct page *page) 162 { 163 return mpage_readpage(page, hpfs_get_block); 164 } 165 166 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 167 { 168 return block_write_full_page(page, hpfs_get_block, wbc); 169 } 170 171 static void hpfs_readahead(struct readahead_control *rac) 172 { 173 mpage_readahead(rac, hpfs_get_block); 174 } 175 176 static int hpfs_writepages(struct address_space *mapping, 177 struct writeback_control *wbc) 178 { 179 return mpage_writepages(mapping, wbc, hpfs_get_block); 180 } 181 182 static void hpfs_write_failed(struct address_space *mapping, loff_t to) 183 { 184 struct inode *inode = mapping->host; 185 186 hpfs_lock(inode->i_sb); 187 188 if (to > inode->i_size) { 189 truncate_pagecache(inode, inode->i_size); 190 hpfs_truncate(inode); 191 } 192 193 hpfs_unlock(inode->i_sb); 194 } 195 196 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 197 loff_t pos, unsigned len, unsigned flags, 198 struct page **pagep, void **fsdata) 199 { 200 int ret; 201 202 *pagep = NULL; 203 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 204 hpfs_get_block, 205 &hpfs_i(mapping->host)->mmu_private); 206 if (unlikely(ret)) 207 hpfs_write_failed(mapping, pos + len); 208 209 return ret; 210 } 211 212 static int hpfs_write_end(struct file *file, struct address_space *mapping, 213 loff_t pos, unsigned len, unsigned copied, 214 struct page *pagep, void *fsdata) 215 { 216 struct inode *inode = mapping->host; 217 int err; 218 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 219 if (err < len) 220 hpfs_write_failed(mapping, pos + len); 221 if (!(err < 0)) { 222 /* make sure we write it on close, if not earlier */ 223 hpfs_lock(inode->i_sb); 224 hpfs_i(inode)->i_dirty = 1; 225 hpfs_unlock(inode->i_sb); 226 } 227 return err; 228 } 229 230 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 231 { 232 return generic_block_bmap(mapping, block, hpfs_get_block); 233 } 234 235 static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) 236 { 237 int ret; 238 239 inode_lock(inode); 240 len = min_t(u64, len, i_size_read(inode)); 241 ret = iomap_fiemap(inode, fieinfo, start, len, &hpfs_iomap_ops); 242 inode_unlock(inode); 243 244 return ret; 245 } 246 247 const struct address_space_operations hpfs_aops = { 248 .set_page_dirty = __set_page_dirty_buffers, 249 .readpage = hpfs_readpage, 250 .writepage = hpfs_writepage, 251 .readahead = hpfs_readahead, 252 .writepages = hpfs_writepages, 253 .write_begin = hpfs_write_begin, 254 .write_end = hpfs_write_end, 255 .bmap = _hpfs_bmap 256 }; 257 258 const struct file_operations hpfs_file_ops = 259 { 260 .llseek = generic_file_llseek, 261 .read_iter = generic_file_read_iter, 262 .write_iter = generic_file_write_iter, 263 .mmap = generic_file_mmap, 264 .release = hpfs_file_release, 265 .fsync = hpfs_file_fsync, 266 .splice_read = generic_file_splice_read, 267 .unlocked_ioctl = hpfs_ioctl, 268 .compat_ioctl = compat_ptr_ioctl, 269 }; 270 271 const struct inode_operations hpfs_file_iops = 272 { 273 .setattr = hpfs_setattr, 274 .fiemap = hpfs_fiemap, 275 }; 276