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, int datasync) 22 { 23 /*return file_fsync(file, datasync);*/ 24 return 0; /* Don't fsync :-) */ 25 } 26 27 /* 28 * generic_file_read often calls bmap with non-existing sector, 29 * so we must ignore such errors. 30 */ 31 32 static secno hpfs_bmap(struct inode *inode, unsigned file_secno) 33 { 34 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); 35 unsigned n, disk_secno; 36 struct fnode *fnode; 37 struct buffer_head *bh; 38 if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; 39 n = file_secno - hpfs_inode->i_file_sec; 40 if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n; 41 if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0; 42 disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); 43 if (disk_secno == -1) return 0; 44 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 45 return disk_secno; 46 } 47 48 static void hpfs_truncate(struct inode *i) 49 { 50 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 51 hpfs_lock(i->i_sb); 52 hpfs_i(i)->i_n_secs = 0; 53 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 54 hpfs_i(i)->mmu_private = i->i_size; 55 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 56 hpfs_write_inode(i); 57 hpfs_i(i)->i_n_secs = 0; 58 hpfs_unlock(i->i_sb); 59 } 60 61 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 62 { 63 secno s; 64 s = hpfs_bmap(inode, iblock); 65 if (s) { 66 map_bh(bh_result, inode->i_sb, s); 67 return 0; 68 } 69 if (!create) return 0; 70 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 71 BUG(); 72 return -EIO; 73 } 74 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 75 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 76 return -ENOSPC; 77 } 78 inode->i_blocks++; 79 hpfs_i(inode)->mmu_private += 512; 80 set_buffer_new(bh_result); 81 map_bh(bh_result, inode->i_sb, s); 82 return 0; 83 } 84 85 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 86 { 87 return block_write_full_page(page,hpfs_get_block, wbc); 88 } 89 90 static int hpfs_readpage(struct file *file, struct page *page) 91 { 92 return block_read_full_page(page,hpfs_get_block); 93 } 94 95 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 96 loff_t pos, unsigned len, unsigned flags, 97 struct page **pagep, void **fsdata) 98 { 99 int ret; 100 101 *pagep = NULL; 102 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 103 hpfs_get_block, 104 &hpfs_i(mapping->host)->mmu_private); 105 if (unlikely(ret)) { 106 loff_t isize = mapping->host->i_size; 107 if (pos + len > isize) 108 vmtruncate(mapping->host, isize); 109 } 110 111 return ret; 112 } 113 114 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 115 { 116 return generic_block_bmap(mapping,block,hpfs_get_block); 117 } 118 119 const struct address_space_operations hpfs_aops = { 120 .readpage = hpfs_readpage, 121 .writepage = hpfs_writepage, 122 .write_begin = hpfs_write_begin, 123 .write_end = generic_write_end, 124 .bmap = _hpfs_bmap 125 }; 126 127 static ssize_t hpfs_file_write(struct file *file, const char __user *buf, 128 size_t count, loff_t *ppos) 129 { 130 ssize_t retval; 131 132 retval = do_sync_write(file, buf, count, ppos); 133 if (retval > 0) 134 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1; 135 return retval; 136 } 137 138 const struct file_operations hpfs_file_ops = 139 { 140 .llseek = generic_file_llseek, 141 .read = do_sync_read, 142 .aio_read = generic_file_aio_read, 143 .write = hpfs_file_write, 144 .aio_write = generic_file_aio_write, 145 .mmap = generic_file_mmap, 146 .release = hpfs_file_release, 147 .fsync = hpfs_file_fsync, 148 .splice_read = generic_file_splice_read, 149 }; 150 151 const struct inode_operations hpfs_file_iops = 152 { 153 .truncate = hpfs_truncate, 154 .setattr = hpfs_setattr, 155 }; 156