2 * linux/fs/adfs/inode.c
4 * Copyright (C) 1997-1999 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/errno.h>
12 #include <linux/adfs_fs.h>
13 #include <linux/time.h>
14 #include <linux/stat.h>
15 #include <linux/string.h>
17 #include <linux/smp_lock.h>
18 #include <linux/module.h>
19 #include <linux/buffer_head.h>
24 * Lookup/Create a block at offset 'block' into 'inode'. We currently do
25 * not support creation of new blocks, so we return -EIO for this case.
28 adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, int create)
34 if (block >= inode->i_blocks)
37 block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
39 map_bh(bh, inode->i_sb, block);
42 /* don't support allocation of blocks yet */
46 adfs_error(inode->i_sb, "block %d < 0", block);
53 static int adfs_writepage(struct page *page, struct writeback_control *wbc)
55 return block_write_full_page(page, adfs_get_block, wbc);
58 static int adfs_readpage(struct file *file, struct page *page)
60 return block_read_full_page(page, adfs_get_block);
63 static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to)
65 return cont_prepare_write(page, from, to, adfs_get_block,
66 &ADFS_I(page->mapping->host)->mmu_private);
69 static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
71 return generic_block_bmap(mapping, block, adfs_get_block);
74 static struct address_space_operations adfs_aops = {
75 .readpage = adfs_readpage,
76 .writepage = adfs_writepage,
77 .sync_page = block_sync_page,
78 .prepare_write = adfs_prepare_write,
79 .commit_write = generic_commit_write,
83 static inline unsigned int
84 adfs_filetype(struct inode *inode)
88 if (ADFS_I(inode)->stamped)
89 type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
91 type = (unsigned int) -1;
97 * Convert ADFS attributes and filetype to Linux permission.
100 adfs_atts2mode(struct super_block *sb, struct inode *inode)
102 unsigned int filetype, attr = ADFS_I(inode)->attr;
104 struct adfs_sb_info *asb = ADFS_SB(sb);
106 if (attr & ADFS_NDA_DIRECTORY) {
107 mode = S_IRUGO & asb->s_owner_mask;
108 return S_IFDIR | S_IXUGO | mode;
111 filetype = adfs_filetype(inode);
114 case 0xfc0: /* LinkFS */
115 return S_IFLNK|S_IRWXUGO;
117 case 0xfe6: /* UnixExec */
118 rmask = S_IRUGO | S_IXUGO;
127 if (attr & ADFS_NDA_OWNER_READ)
128 mode |= rmask & asb->s_owner_mask;
130 if (attr & ADFS_NDA_OWNER_WRITE)
131 mode |= S_IWUGO & asb->s_owner_mask;
133 if (attr & ADFS_NDA_PUBLIC_READ)
134 mode |= rmask & asb->s_other_mask;
136 if (attr & ADFS_NDA_PUBLIC_WRITE)
137 mode |= S_IWUGO & asb->s_other_mask;
142 * Convert Linux permission to ADFS attribute. We try to do the reverse
143 * of atts2mode, but there is not a 1:1 translation.
146 adfs_mode2atts(struct super_block *sb, struct inode *inode)
150 struct adfs_sb_info *asb = ADFS_SB(sb);
152 /* FIXME: should we be able to alter a link? */
153 if (S_ISLNK(inode->i_mode))
154 return ADFS_I(inode)->attr;
156 if (S_ISDIR(inode->i_mode))
157 attr = ADFS_NDA_DIRECTORY;
161 mode = inode->i_mode & asb->s_owner_mask;
163 attr |= ADFS_NDA_OWNER_READ;
165 attr |= ADFS_NDA_OWNER_WRITE;
167 mode = inode->i_mode & asb->s_other_mask;
168 mode &= ~asb->s_owner_mask;
170 attr |= ADFS_NDA_PUBLIC_READ;
172 attr |= ADFS_NDA_PUBLIC_WRITE;
178 * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
179 * referenced to 1 Jan 1900 (til 2248)
182 adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
184 unsigned int high, low;
186 if (ADFS_I(inode)->stamped == 0)
189 high = ADFS_I(inode)->loadaddr << 24;
190 low = ADFS_I(inode)->execaddr;
195 /* Files dated pre 01 Jan 1970 00:00:00. */
196 if (high < 0x336e996a)
199 /* Files dated post 18 Jan 2038 03:14:05. */
200 if (high >= 0x656e9969)
203 /* discard 2208988800 (0x336e996a00) seconds of time */
206 /* convert 40-bit centi-seconds to 32-bit seconds */
207 tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
216 tv->tv_sec = tv->tv_nsec = 0;
220 tv->tv_sec = 0x7ffffffd;
226 * Convert an Unix time to ADFS time. We only do this if the entry has a
227 * time/date stamp already.
230 adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
232 unsigned int high, low;
234 if (ADFS_I(inode)->stamped) {
235 /* convert 32-bit seconds to 40-bit centi-seconds */
236 low = (secs & 255) * 100;
237 high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
239 ADFS_I(inode)->loadaddr = (high >> 24) |
240 (ADFS_I(inode)->loadaddr & ~0xff);
241 ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
246 * Fill in the inode information from the object information.
248 * Note that this is an inode-less filesystem, so we can't use the inode
249 * number to reference the metadata on the media. Instead, we use the
250 * inode number to hold the object ID, which in turn will tell us where
251 * the data is held. We also save the parent object ID, and with these
252 * two, we can locate the metadata.
254 * This does mean that we rely on an objects parent remaining the same at
255 * all times - we cannot cope with a cross-directory rename (yet).
258 adfs_iget(struct super_block *sb, struct object_info *obj)
262 inode = new_inode(sb);
266 inode->i_uid = ADFS_SB(sb)->s_uid;
267 inode->i_gid = ADFS_SB(sb)->s_gid;
268 inode->i_ino = obj->file_id;
269 inode->i_size = obj->size;
271 inode->i_blksize = PAGE_SIZE;
272 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
273 sb->s_blocksize_bits;
276 * we need to save the parent directory ID so that
277 * write_inode can update the directory information
278 * for this file. This will need special handling
279 * for cross-directory renames.
281 ADFS_I(inode)->parent_id = obj->parent_id;
282 ADFS_I(inode)->loadaddr = obj->loadaddr;
283 ADFS_I(inode)->execaddr = obj->execaddr;
284 ADFS_I(inode)->attr = obj->attr;
285 ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
287 inode->i_mode = adfs_atts2mode(sb, inode);
288 adfs_adfs2unix_time(&inode->i_mtime, inode);
289 inode->i_atime = inode->i_mtime;
290 inode->i_ctime = inode->i_mtime;
292 if (S_ISDIR(inode->i_mode)) {
293 inode->i_op = &adfs_dir_inode_operations;
294 inode->i_fop = &adfs_dir_operations;
295 } else if (S_ISREG(inode->i_mode)) {
296 inode->i_op = &adfs_file_inode_operations;
297 inode->i_fop = &adfs_file_operations;
298 inode->i_mapping->a_ops = &adfs_aops;
299 ADFS_I(inode)->mmu_private = inode->i_size;
302 insert_inode_hash(inode);
309 * Validate and convert a changed access mode/time to their ADFS equivalents.
310 * adfs_write_inode will actually write the information back to the directory
314 adfs_notify_change(struct dentry *dentry, struct iattr *attr)
316 struct inode *inode = dentry->d_inode;
317 struct super_block *sb = inode->i_sb;
318 unsigned int ia_valid = attr->ia_valid;
323 error = inode_change_ok(inode, attr);
326 * we can't change the UID or GID of any file -
327 * we have a global UID/GID in the superblock
329 if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) ||
330 (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid))
336 if (ia_valid & ATTR_SIZE)
337 error = vmtruncate(inode, attr->ia_size);
342 if (ia_valid & ATTR_MTIME) {
343 inode->i_mtime = attr->ia_mtime;
344 adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
347 * FIXME: should we make these == to i_mtime since we don't
348 * have the ability to represent them in our filesystem?
350 if (ia_valid & ATTR_ATIME)
351 inode->i_atime = attr->ia_atime;
352 if (ia_valid & ATTR_CTIME)
353 inode->i_ctime = attr->ia_ctime;
354 if (ia_valid & ATTR_MODE) {
355 ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
356 inode->i_mode = adfs_atts2mode(sb, inode);
360 * FIXME: should we be marking this inode dirty even if
361 * we don't have any metadata to write back?
363 if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
364 mark_inode_dirty(inode);
371 * write an existing inode back to the directory, and therefore the disk.
372 * The adfs-specific inode data has already been updated by
373 * adfs_notify_change()
375 void adfs_write_inode(struct inode *inode, int unused)
377 struct super_block *sb = inode->i_sb;
378 struct object_info obj;
381 obj.file_id = inode->i_ino;
383 obj.parent_id = ADFS_I(inode)->parent_id;
384 obj.loadaddr = ADFS_I(inode)->loadaddr;
385 obj.execaddr = ADFS_I(inode)->execaddr;
386 obj.attr = ADFS_I(inode)->attr;
387 obj.size = inode->i_size;
389 adfs_dir_update(sb, &obj);
392 MODULE_LICENSE("GPL");