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 <linux/smp_lock.h> 10 #include "hpfs_fn.h" 11 12 #define BLOCKS(size) (((size) + 511) >> 9) 13 14 static int hpfs_file_release(struct inode *inode, struct file *file) 15 { 16 lock_kernel(); 17 hpfs_write_if_changed(inode); 18 unlock_kernel(); 19 return 0; 20 } 21 22 int hpfs_file_fsync(struct file *file, int datasync) 23 { 24 /*return file_fsync(file, datasync);*/ 25 return 0; /* Don't fsync :-) */ 26 } 27 28 /* 29 * generic_file_read often calls bmap with non-existing sector, 30 * so we must ignore such errors. 31 */ 32 33 static secno hpfs_bmap(struct inode *inode, unsigned file_secno) 34 { 35 struct hpfs_inode_info *hpfs_inode = hpfs_i(inode); 36 unsigned n, disk_secno; 37 struct fnode *fnode; 38 struct buffer_head *bh; 39 if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0; 40 n = file_secno - hpfs_inode->i_file_sec; 41 if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n; 42 if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0; 43 disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh); 44 if (disk_secno == -1) return 0; 45 if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0; 46 return disk_secno; 47 } 48 49 static void hpfs_truncate(struct inode *i) 50 { 51 if (IS_IMMUTABLE(i)) return /*-EPERM*/; 52 lock_kernel(); 53 hpfs_i(i)->i_n_secs = 0; 54 i->i_blocks = 1 + ((i->i_size + 511) >> 9); 55 hpfs_i(i)->mmu_private = i->i_size; 56 hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9)); 57 hpfs_write_inode(i); 58 hpfs_i(i)->i_n_secs = 0; 59 unlock_kernel(); 60 } 61 62 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 63 { 64 secno s; 65 s = hpfs_bmap(inode, iblock); 66 if (s) { 67 map_bh(bh_result, inode->i_sb, s); 68 return 0; 69 } 70 if (!create) return 0; 71 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 72 BUG(); 73 return -EIO; 74 } 75 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 76 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 77 return -ENOSPC; 78 } 79 inode->i_blocks++; 80 hpfs_i(inode)->mmu_private += 512; 81 set_buffer_new(bh_result); 82 map_bh(bh_result, inode->i_sb, s); 83 return 0; 84 } 85 86 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 87 { 88 return block_write_full_page(page,hpfs_get_block, wbc); 89 } 90 91 static int hpfs_readpage(struct file *file, struct page *page) 92 { 93 return block_read_full_page(page,hpfs_get_block); 94 } 95 96 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 97 loff_t pos, unsigned len, unsigned flags, 98 struct page **pagep, void **fsdata) 99 { 100 *pagep = NULL; 101 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 102 hpfs_get_block, 103 &hpfs_i(mapping->host)->mmu_private); 104 } 105 106 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 107 { 108 return generic_block_bmap(mapping,block,hpfs_get_block); 109 } 110 111 const struct address_space_operations hpfs_aops = { 112 .readpage = hpfs_readpage, 113 .writepage = hpfs_writepage, 114 .sync_page = block_sync_page, 115 .write_begin = hpfs_write_begin, 116 .write_end = generic_write_end, 117 .bmap = _hpfs_bmap 118 }; 119 120 static ssize_t hpfs_file_write(struct file *file, const char __user *buf, 121 size_t count, loff_t *ppos) 122 { 123 ssize_t retval; 124 125 retval = do_sync_write(file, buf, count, ppos); 126 if (retval > 0) 127 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1; 128 return retval; 129 } 130 131 const struct file_operations hpfs_file_ops = 132 { 133 .llseek = generic_file_llseek, 134 .read = do_sync_read, 135 .aio_read = generic_file_aio_read, 136 .write = hpfs_file_write, 137 .aio_write = generic_file_aio_write, 138 .mmap = generic_file_mmap, 139 .release = hpfs_file_release, 140 .fsync = hpfs_file_fsync, 141 .splice_read = generic_file_splice_read, 142 }; 143 144 const struct inode_operations hpfs_file_iops = 145 { 146 .truncate = hpfs_truncate, 147 .setattr = hpfs_setattr, 148 }; 149