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 struct inode *inode = file->f_mapping->host; 24 return sync_blockdev(inode->i_sb->s_bdev); 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_assert(i->i_sb); 52 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 } 60 61 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) 62 { 63 int r; 64 secno s; 65 hpfs_lock(inode->i_sb); 66 s = hpfs_bmap(inode, iblock); 67 if (s) { 68 map_bh(bh_result, inode->i_sb, s); 69 goto ret_0; 70 } 71 if (!create) goto ret_0; 72 if (iblock<<9 != hpfs_i(inode)->mmu_private) { 73 BUG(); 74 r = -EIO; 75 goto ret_r; 76 } 77 if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) { 78 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1); 79 r = -ENOSPC; 80 goto ret_r; 81 } 82 inode->i_blocks++; 83 hpfs_i(inode)->mmu_private += 512; 84 set_buffer_new(bh_result); 85 map_bh(bh_result, inode->i_sb, s); 86 ret_0: 87 r = 0; 88 ret_r: 89 hpfs_unlock(inode->i_sb); 90 return r; 91 } 92 93 static int hpfs_writepage(struct page *page, struct writeback_control *wbc) 94 { 95 return block_write_full_page(page,hpfs_get_block, wbc); 96 } 97 98 static int hpfs_readpage(struct file *file, struct page *page) 99 { 100 return block_read_full_page(page,hpfs_get_block); 101 } 102 103 static int hpfs_write_begin(struct file *file, struct address_space *mapping, 104 loff_t pos, unsigned len, unsigned flags, 105 struct page **pagep, void **fsdata) 106 { 107 int ret; 108 109 *pagep = NULL; 110 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 111 hpfs_get_block, 112 &hpfs_i(mapping->host)->mmu_private); 113 if (unlikely(ret)) { 114 loff_t isize = mapping->host->i_size; 115 if (pos + len > isize) 116 vmtruncate(mapping->host, isize); 117 } 118 119 return ret; 120 } 121 122 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block) 123 { 124 return generic_block_bmap(mapping,block,hpfs_get_block); 125 } 126 127 const struct address_space_operations hpfs_aops = { 128 .readpage = hpfs_readpage, 129 .writepage = hpfs_writepage, 130 .write_begin = hpfs_write_begin, 131 .write_end = generic_write_end, 132 .bmap = _hpfs_bmap 133 }; 134 135 static ssize_t hpfs_file_write(struct file *file, const char __user *buf, 136 size_t count, loff_t *ppos) 137 { 138 ssize_t retval; 139 140 retval = do_sync_write(file, buf, count, ppos); 141 if (retval > 0) { 142 hpfs_lock(file->f_path.dentry->d_sb); 143 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1; 144 hpfs_unlock(file->f_path.dentry->d_sb); 145 } 146 return retval; 147 } 148 149 const struct file_operations hpfs_file_ops = 150 { 151 .llseek = generic_file_llseek, 152 .read = do_sync_read, 153 .aio_read = generic_file_aio_read, 154 .write = hpfs_file_write, 155 .aio_write = generic_file_aio_write, 156 .mmap = generic_file_mmap, 157 .release = hpfs_file_release, 158 .fsync = hpfs_file_fsync, 159 .splice_read = generic_file_splice_read, 160 }; 161 162 const struct inode_operations hpfs_file_iops = 163 { 164 .truncate = hpfs_truncate, 165 .setattr = hpfs_setattr, 166 }; 167