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 11 #define BLOCKS(size) (((size) + 511) >> 9) 12 13 static int hpfs_file_release(struct inode *inode, struct file *file) 14 { 15 hpfs_lock(inode->i_sb); 16 hpfs_write_if_changed(inode); 17 hpfs_unlock(inode->i_sb); 18 return 0; 19 } 20 21 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) 22 { 23 struct inode *inode = file->f_mapping->host; 24 int ret; 25 26 ret = filemap_write_and_wait_range(file->f_mapping, start, end); 27 if (ret) 28 return ret; 29 return sync_blockdev(inode->i_sb->s_bdev); 30 } 31 32 /* 33 * generic_file_read often calls bmap with non-existing sector, 34 * so we must ignore such errors. 35 */ 36 37 static secno hpfs_bmap(struct inode *inode, unsigned file_secno) 38 { 39 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); 40 unsigned n, disk_secno; 41 struct fnode *fnode; 42 struct buffer_head *bh; 43 if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; 44 n = file_secno - hpfs_inode->i_file_sec; 45 if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n; 46 if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0; 47 disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); 48 if (disk_secno == -1) return 0; 49 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 50 return disk_secno; 51 } 52 53 void hpfs_truncate(struct inode *i) 54 { 55 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 56 hpfs_lock_assert(i->i_sb); 57 58 hpfs_i(i)->i_n_secs = 0; 59 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 60 hpfs_i(i)->mmu_private = i->i_size; 61 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 62 hpfs_write_inode(i); 63 hpfs_i(i)->i_n_secs = 0; 64 } 65 66 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 67 { 68 int r; 69 secno s; 70 hpfs_lock(inode->i_sb); 71 s = hpfs_bmap(inode, iblock); 72 if (s) { 73 map_bh(bh_result, inode->i_sb, s); 74 goto ret_0; 75 } 76 if (!create) goto ret_0; 77 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 78 BUG(); 79 r = -EIO; 80 goto ret_r; 81 } 82 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 83 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 84 r = -ENOSPC; 85 goto ret_r; 86 } 87 inode->i_blocks++; 88 hpfs_i(inode)->mmu_private += 512; 89 set_buffer_new(bh_result); 90 map_bh(bh_result, inode->i_sb, s); 91 ret_0: 92 r = 0; 93 ret_r: 94 hpfs_unlock(inode->i_sb); 95 return r; 96 } 97 98 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 99 { 100 return block_write_full_page(page,hpfs_get_block, wbc); 101 } 102 103 static int hpfs_readpage(struct file *file, struct page *page) 104 { 105 return block_read_full_page(page,hpfs_get_block); 106 } 107 108 static void hpfs_write_failed(struct address_space *mapping, loff_t to) 109 { 110 struct inode *inode = mapping->host; 111 112 if (to > inode->i_size) { 113 truncate_pagecache(inode, to, inode->i_size); 114 hpfs_truncate(inode); 115 } 116 } 117 118 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 119 loff_t pos, unsigned len, unsigned flags, 120 struct page **pagep, void **fsdata) 121 { 122 int ret; 123 124 *pagep = NULL; 125 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 126 hpfs_get_block, 127 &hpfs_i(mapping->host)->mmu_private); 128 if (unlikely(ret)) 129 hpfs_write_failed(mapping, pos + len); 130 131 return ret; 132 } 133 134 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 135 { 136 return generic_block_bmap(mapping,block,hpfs_get_block); 137 } 138 139 const struct address_space_operations hpfs_aops = { 140 .readpage = hpfs_readpage, 141 .writepage = hpfs_writepage, 142 .write_begin = hpfs_write_begin, 143 .write_end = generic_write_end, 144 .bmap = _hpfs_bmap 145 }; 146 147 static ssize_t hpfs_file_write(struct file *file, const char __user *buf, 148 size_t count, loff_t *ppos) 149 { 150 ssize_t retval; 151 152 retval = do_sync_write(file, buf, count, ppos); 153 if (retval > 0) { 154 hpfs_lock(file->f_path.dentry->d_sb); 155 hpfs_i(file_inode(file))->i_dirty = 1; 156 hpfs_unlock(file->f_path.dentry->d_sb); 157 } 158 return retval; 159 } 160 161 const struct file_operations hpfs_file_ops = 162 { 163 .llseek = generic_file_llseek, 164 .read = do_sync_read, 165 .aio_read = generic_file_aio_read, 166 .write = hpfs_file_write, 167 .aio_write = generic_file_aio_write, 168 .mmap = generic_file_mmap, 169 .release = hpfs_file_release, 170 .fsync = hpfs_file_fsync, 171 .splice_read = generic_file_splice_read, 172 }; 173 174 const struct inode_operations hpfs_file_iops = 175 { 176 .setattr = hpfs_setattr, 177 }; 178