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, 55 GET_BTREE_PTR(&fnode->btree), 56 file_secno, bh); 57 if (disk_secno == -1) return 0; 58 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 59 n = file_secno - hpfs_inode->i_file_sec; 60 if (n < hpfs_inode->i_n_secs) { 61 *n_secs = hpfs_inode->i_n_secs - n; 62 return hpfs_inode->i_disk_sec + n; 63 } 64 *n_secs = 1; 65 return disk_secno; 66 } 67 68 void hpfs_truncate(struct inode *i) 69 { 70 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 71 hpfs_lock_assert(i->i_sb); 72 73 hpfs_i(i)->i_n_secs = 0; 74 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 75 hpfs_i(i)->mmu_private = i->i_size; 76 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 77 hpfs_write_inode(i); 78 hpfs_i(i)->i_n_secs = 0; 79 } 80 81 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 82 { 83 int r; 84 secno s; 85 unsigned n_secs; 86 hpfs_lock(inode->i_sb); 87 s = hpfs_bmap(inode, iblock, &n_secs); 88 if (s) { 89 if (bh_result->b_size >> 9 < n_secs) 90 n_secs = bh_result->b_size >> 9; 91 n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs); 92 if (unlikely(!n_secs)) { 93 s = hpfs_search_hotfix_map(inode->i_sb, s); 94 n_secs = 1; 95 } 96 map_bh(bh_result, inode->i_sb, s); 97 bh_result->b_size = n_secs << 9; 98 goto ret_0; 99 } 100 if (!create) goto ret_0; 101 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 102 BUG(); 103 r = -EIO; 104 goto ret_r; 105 } 106 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 107 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 108 r = -ENOSPC; 109 goto ret_r; 110 } 111 inode->i_blocks++; 112 hpfs_i(inode)->mmu_private += 512; 113 set_buffer_new(bh_result); 114 map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s)); 115 ret_0: 116 r = 0; 117 ret_r: 118 hpfs_unlock(inode->i_sb); 119 return r; 120 } 121 122 static int hpfs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, 123 unsigned flags, struct iomap *iomap, struct iomap *srcmap) 124 { 125 struct super_block *sb = inode->i_sb; 126 unsigned int blkbits = inode->i_blkbits; 127 unsigned int n_secs; 128 secno s; 129 130 if (WARN_ON_ONCE(flags & (IOMAP_WRITE | IOMAP_ZERO))) 131 return -EINVAL; 132 133 iomap->bdev = inode->i_sb->s_bdev; 134 iomap->offset = offset; 135 136 hpfs_lock(sb); 137 s = hpfs_bmap(inode, offset >> blkbits, &n_secs); 138 if (s) { 139 n_secs = hpfs_search_hotfix_map_for_range(sb, s, 140 min_t(loff_t, n_secs, length)); 141 if (unlikely(!n_secs)) { 142 s = hpfs_search_hotfix_map(sb, s); 143 n_secs = 1; 144 } 145 iomap->type = IOMAP_MAPPED; 146 iomap->flags = IOMAP_F_MERGED; 147 iomap->addr = (u64)s << blkbits; 148 iomap->length = (u64)n_secs << blkbits; 149 } else { 150 iomap->type = IOMAP_HOLE; 151 iomap->addr = IOMAP_NULL_ADDR; 152 iomap->length = 1 << blkbits; 153 } 154 155 hpfs_unlock(sb); 156 return 0; 157 } 158 159 static const struct iomap_ops hpfs_iomap_ops = { 160 .iomap_begin = hpfs_iomap_begin, 161 }; 162 163 static int hpfs_read_folio(struct file *file, struct folio *folio) 164 { 165 return mpage_read_folio(folio, hpfs_get_block); 166 } 167 168 static void hpfs_readahead(struct readahead_control *rac) 169 { 170 mpage_readahead(rac, hpfs_get_block); 171 } 172 173 static int hpfs_writepages(struct address_space *mapping, 174 struct writeback_control *wbc) 175 { 176 return mpage_writepages(mapping, wbc, hpfs_get_block); 177 } 178 179 static void hpfs_write_failed(struct address_space *mapping, loff_t to) 180 { 181 struct inode *inode = mapping->host; 182 183 hpfs_lock(inode->i_sb); 184 185 if (to > inode->i_size) { 186 truncate_pagecache(inode, inode->i_size); 187 hpfs_truncate(inode); 188 } 189 190 hpfs_unlock(inode->i_sb); 191 } 192 193 static int hpfs_write_begin(const struct kiocb *iocb, 194 struct address_space *mapping, 195 loff_t pos, unsigned len, 196 struct folio **foliop, void **fsdata) 197 { 198 int ret; 199 200 ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata, 201 hpfs_get_block, 202 &hpfs_i(mapping->host)->mmu_private); 203 if (unlikely(ret)) 204 hpfs_write_failed(mapping, pos + len); 205 206 return ret; 207 } 208 209 static int hpfs_write_end(const struct kiocb *iocb, 210 struct address_space *mapping, 211 loff_t pos, unsigned len, unsigned copied, 212 struct folio *folio, void *fsdata) 213 { 214 struct inode *inode = mapping->host; 215 int err; 216 err = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata); 217 if (err < len) 218 hpfs_write_failed(mapping, pos + len); 219 if (!(err < 0)) { 220 /* make sure we write it on close, if not earlier */ 221 hpfs_lock(inode->i_sb); 222 hpfs_i(inode)->i_dirty = 1; 223 hpfs_unlock(inode->i_sb); 224 } 225 return err; 226 } 227 228 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 229 { 230 return generic_block_bmap(mapping, block, hpfs_get_block); 231 } 232 233 static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) 234 { 235 int ret; 236 237 inode_lock(inode); 238 len = min_t(u64, len, i_size_read(inode)); 239 ret = iomap_fiemap(inode, fieinfo, start, len, &hpfs_iomap_ops); 240 inode_unlock(inode); 241 242 return ret; 243 } 244 245 const struct address_space_operations hpfs_aops = { 246 .dirty_folio = block_dirty_folio, 247 .invalidate_folio = block_invalidate_folio, 248 .read_folio = hpfs_read_folio, 249 .readahead = hpfs_readahead, 250 .writepages = hpfs_writepages, 251 .write_begin = hpfs_write_begin, 252 .write_end = hpfs_write_end, 253 .bmap = _hpfs_bmap, 254 .migrate_folio = buffer_migrate_folio, 255 }; 256 257 const struct file_operations hpfs_file_ops = 258 { 259 .llseek = generic_file_llseek, 260 .read_iter = generic_file_read_iter, 261 .write_iter = generic_file_write_iter, 262 .mmap_prepare = generic_file_mmap_prepare, 263 .release = hpfs_file_release, 264 .fsync = hpfs_file_fsync, 265 .splice_read = filemap_splice_read, 266 .unlocked_ioctl = hpfs_ioctl, 267 .compat_ioctl = compat_ptr_ioctl, 268 }; 269 270 const struct inode_operations hpfs_file_iops = 271 { 272 .setattr = hpfs_setattr, 273 .fiemap = hpfs_fiemap, 274 }; 275