1 /* 2 * linux/fs/hpfs/file.c 3 * 4 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 5 * 6 * file VFS functions 7 */ 8 9 #include "hpfs_fn.h" 10 #include <linux/mpage.h> 11 12 #define BLOCKS(size) (((size) + 511) >> 9) 13 14 static int hpfs_file_release(struct inode *inode, struct file *file) 15 { 16 hpfs_lock(inode->i_sb); 17 hpfs_write_if_changed(inode); 18 hpfs_unlock(inode->i_sb); 19 return 0; 20 } 21 22 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) 23 { 24 struct inode *inode = file->f_mapping->host; 25 int ret; 26 27 ret = filemap_write_and_wait_range(file->f_mapping, start, end); 28 if (ret) 29 return ret; 30 return sync_blockdev(inode->i_sb->s_bdev); 31 } 32 33 /* 34 * generic_file_read often calls bmap with non-existing sector, 35 * so we must ignore such errors. 36 */ 37 38 static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs) 39 { 40 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); 41 unsigned n, disk_secno; 42 struct fnode *fnode; 43 struct buffer_head *bh; 44 if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; 45 n = file_secno - hpfs_inode->i_file_sec; 46 if (n < hpfs_inode->i_n_secs) { 47 *n_secs = hpfs_inode->i_n_secs - n; 48 return hpfs_inode->i_disk_sec + n; 49 } 50 if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0; 51 disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); 52 if (disk_secno == -1) return 0; 53 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 54 n = file_secno - hpfs_inode->i_file_sec; 55 if (n < hpfs_inode->i_n_secs) { 56 *n_secs = hpfs_inode->i_n_secs - n; 57 return hpfs_inode->i_disk_sec + n; 58 } 59 *n_secs = 1; 60 return disk_secno; 61 } 62 63 void hpfs_truncate(struct inode *i) 64 { 65 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 66 hpfs_lock_assert(i->i_sb); 67 68 hpfs_i(i)->i_n_secs = 0; 69 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 70 hpfs_i(i)->mmu_private = i->i_size; 71 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 72 hpfs_write_inode(i); 73 hpfs_i(i)->i_n_secs = 0; 74 } 75 76 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 77 { 78 int r; 79 secno s; 80 unsigned n_secs; 81 hpfs_lock(inode->i_sb); 82 s = hpfs_bmap(inode, iblock, &n_secs); 83 if (s) { 84 if (bh_result->b_size >> 9 < n_secs) 85 n_secs = bh_result->b_size >> 9; 86 map_bh(bh_result, inode->i_sb, s); 87 bh_result->b_size = n_secs << 9; 88 goto ret_0; 89 } 90 if (!create) goto ret_0; 91 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 92 BUG(); 93 r = -EIO; 94 goto ret_r; 95 } 96 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 97 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 98 r = -ENOSPC; 99 goto ret_r; 100 } 101 inode->i_blocks++; 102 hpfs_i(inode)->mmu_private += 512; 103 set_buffer_new(bh_result); 104 map_bh(bh_result, inode->i_sb, s); 105 ret_0: 106 r = 0; 107 ret_r: 108 hpfs_unlock(inode->i_sb); 109 return r; 110 } 111 112 static int hpfs_readpage(struct file *file, struct page *page) 113 { 114 return mpage_readpage(page, hpfs_get_block); 115 } 116 117 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 118 { 119 return block_write_full_page(page, hpfs_get_block, wbc); 120 } 121 122 static int hpfs_readpages(struct file *file, struct address_space *mapping, 123 struct list_head *pages, unsigned nr_pages) 124 { 125 return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block); 126 } 127 128 static int hpfs_writepages(struct address_space *mapping, 129 struct writeback_control *wbc) 130 { 131 return mpage_writepages(mapping, wbc, hpfs_get_block); 132 } 133 134 static void hpfs_write_failed(struct address_space *mapping, loff_t to) 135 { 136 struct inode *inode = mapping->host; 137 138 hpfs_lock(inode->i_sb); 139 140 if (to > inode->i_size) { 141 truncate_pagecache(inode, inode->i_size); 142 hpfs_truncate(inode); 143 } 144 145 hpfs_unlock(inode->i_sb); 146 } 147 148 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 149 loff_t pos, unsigned len, unsigned flags, 150 struct page **pagep, void **fsdata) 151 { 152 int ret; 153 154 *pagep = NULL; 155 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 156 hpfs_get_block, 157 &hpfs_i(mapping->host)->mmu_private); 158 if (unlikely(ret)) 159 hpfs_write_failed(mapping, pos + len); 160 161 return ret; 162 } 163 164 static int hpfs_write_end(struct file *file, struct address_space *mapping, 165 loff_t pos, unsigned len, unsigned copied, 166 struct page *pagep, void *fsdata) 167 { 168 struct inode *inode = mapping->host; 169 int err; 170 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); 171 if (err < len) 172 hpfs_write_failed(mapping, pos + len); 173 if (!(err < 0)) { 174 /* make sure we write it on close, if not earlier */ 175 hpfs_lock(inode->i_sb); 176 hpfs_i(inode)->i_dirty = 1; 177 hpfs_unlock(inode->i_sb); 178 } 179 return err; 180 } 181 182 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 183 { 184 return generic_block_bmap(mapping,block,hpfs_get_block); 185 } 186 187 const struct address_space_operations hpfs_aops = { 188 .readpage = hpfs_readpage, 189 .writepage = hpfs_writepage, 190 .readpages = hpfs_readpages, 191 .writepages = hpfs_writepages, 192 .write_begin = hpfs_write_begin, 193 .write_end = hpfs_write_end, 194 .bmap = _hpfs_bmap 195 }; 196 197 const struct file_operations hpfs_file_ops = 198 { 199 .llseek = generic_file_llseek, 200 .read_iter = generic_file_read_iter, 201 .write_iter = generic_file_write_iter, 202 .mmap = generic_file_mmap, 203 .release = hpfs_file_release, 204 .fsync = hpfs_file_fsync, 205 .splice_read = generic_file_splice_read, 206 .unlocked_ioctl = hpfs_ioctl, 207 }; 208 209 const struct inode_operations hpfs_file_iops = 210 { 211 .setattr = hpfs_setattr, 212 }; 213