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/fiemap.h> 13 14 #define BLOCKS(size) (((size) + 511) >> 9) 15 16 static int hpfs_file_release(struct inode *inode, struct file *file) 17 { 18 hpfs_lock(inode->i_sb); 19 hpfs_write_if_changed(inode); 20 hpfs_unlock(inode->i_sb); 21 return 0; 22 } 23 24 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) 25 { 26 struct inode *inode = file->f_mapping->host; 27 int ret; 28 29 ret = file_write_and_wait_range(file, start, end); 30 if (ret) 31 return ret; 32 return sync_blockdev(inode->i_sb->s_bdev); 33 } 34 35 /* 36 * generic_file_read often calls bmap with non-existing sector, 37 * so we must ignore such errors. 38 */ 39 40 static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs) 41 { 42 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); 43 unsigned n, disk_secno; 44 struct fnode *fnode; 45 struct buffer_head *bh; 46 if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; 47 n = file_secno - hpfs_inode->i_file_sec; 48 if (n < hpfs_inode->i_n_secs) { 49 *n_secs = hpfs_inode->i_n_secs - n; 50 return hpfs_inode->i_disk_sec + n; 51 } 52 if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0; 53 disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); 54 if (disk_secno == -1) return 0; 55 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 56 n = file_secno - hpfs_inode->i_file_sec; 57 if (n < hpfs_inode->i_n_secs) { 58 *n_secs = hpfs_inode->i_n_secs - n; 59 return hpfs_inode->i_disk_sec + n; 60 } 61 *n_secs = 1; 62 return disk_secno; 63 } 64 65 void hpfs_truncate(struct inode *i) 66 { 67 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 68 hpfs_lock_assert(i->i_sb); 69 70 hpfs_i(i)->i_n_secs = 0; 71 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 72 hpfs_i(i)->mmu_private = i->i_size; 73 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 74 hpfs_write_inode(i); 75 hpfs_i(i)->i_n_secs = 0; 76 } 77 78 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 79 { 80 int r; 81 secno s; 82 unsigned n_secs; 83 hpfs_lock(inode->i_sb); 84 s = hpfs_bmap(inode, iblock, &n_secs); 85 if (s) { 86 if (bh_result->b_size >> 9 < n_secs) 87 n_secs = bh_result->b_size >> 9; 88 n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs); 89 if (unlikely(!n_secs)) { 90 s = hpfs_search_hotfix_map(inode->i_sb, s); 91 n_secs = 1; 92 } 93 map_bh(bh_result, inode->i_sb, s); 94 bh_result->b_size = n_secs << 9; 95 goto ret_0; 96 } 97 if (!create) goto ret_0; 98 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 99 BUG(); 100 r = -EIO; 101 goto ret_r; 102 } 103 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 104 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 105 r = -ENOSPC; 106 goto ret_r; 107 } 108 inode->i_blocks++; 109 hpfs_i(inode)->mmu_private += 512; 110 set_buffer_new(bh_result); 111 map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s)); 112 ret_0: 113 r = 0; 114 ret_r: 115 hpfs_unlock(inode->i_sb); 116 return r; 117 } 118 119 static int hpfs_readpage(struct file *file, struct page *page) 120 { 121 return mpage_readpage(page, hpfs_get_block); 122 } 123 124 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 125 { 126 return block_write_full_page(page, hpfs_get_block, wbc); 127 } 128 129 static void hpfs_readahead(struct readahead_control *rac) 130 { 131 mpage_readahead(rac, hpfs_get_block); 132 } 133 134 static int hpfs_writepages(struct address_space *mapping, 135 struct writeback_control *wbc) 136 { 137 return mpage_writepages(mapping, wbc, hpfs_get_block); 138 } 139 140 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 } 153 154 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 } 169 170 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 } 187 188 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 189 { 190 return generic_block_bmap(mapping, block, hpfs_get_block); 191 } 192 193 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 .readahead = hpfs_readahead, 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 .compat_ioctl = compat_ptr_ioctl, 219 }; 220 221 const struct inode_operations hpfs_file_iops = 222 { 223 .setattr = hpfs_setattr, 224 .fiemap = hpfs_fiemap, 225 }; 226