xref: /openbmc/linux/fs/hpfs/dir.c (revision 2c64e9cb)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hpfs/dir.c
4  *
5  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6  *
7  *  directory VFS functions
8  */
9 
10 #include <linux/slab.h>
11 #include "hpfs_fn.h"
12 
13 static int hpfs_dir_release(struct inode *inode, struct file *filp)
14 {
15 	hpfs_lock(inode->i_sb);
16 	hpfs_del_pos(inode, &filp->f_pos);
17 	/*hpfs_write_if_changed(inode);*/
18 	hpfs_unlock(inode->i_sb);
19 	return 0;
20 }
21 
22 /* This is slow, but it's not used often */
23 
24 static loff_t hpfs_dir_lseek(struct file *filp, loff_t off, int whence)
25 {
26 	loff_t new_off = off + (whence == 1 ? filp->f_pos : 0);
27 	loff_t pos;
28 	struct quad_buffer_head qbh;
29 	struct inode *i = file_inode(filp);
30 	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
31 	struct super_block *s = i->i_sb;
32 
33 	/* Somebody else will have to figure out what to do here */
34 	if (whence == SEEK_DATA || whence == SEEK_HOLE)
35 		return -EINVAL;
36 
37 	inode_lock(i);
38 	hpfs_lock(s);
39 
40 	/*pr_info("dir lseek\n");*/
41 	if (new_off == 0 || new_off == 1 || new_off == 11 || new_off == 12 || new_off == 13) goto ok;
42 	pos = ((loff_t) hpfs_de_as_down_as_possible(s, hpfs_inode->i_dno) << 4) + 1;
43 	while (pos != new_off) {
44 		if (map_pos_dirent(i, &pos, &qbh)) hpfs_brelse4(&qbh);
45 		else goto fail;
46 		if (pos == 12) goto fail;
47 	}
48 	if (unlikely(hpfs_add_pos(i, &filp->f_pos) < 0)) {
49 		hpfs_unlock(s);
50 		inode_unlock(i);
51 		return -ENOMEM;
52 	}
53 ok:
54 	filp->f_pos = new_off;
55 	hpfs_unlock(s);
56 	inode_unlock(i);
57 	return new_off;
58 fail:
59 	/*pr_warn("illegal lseek: %016llx\n", new_off);*/
60 	hpfs_unlock(s);
61 	inode_unlock(i);
62 	return -ESPIPE;
63 }
64 
65 static int hpfs_readdir(struct file *file, struct dir_context *ctx)
66 {
67 	struct inode *inode = file_inode(file);
68 	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
69 	struct quad_buffer_head qbh;
70 	struct hpfs_dirent *de;
71 	int lc;
72 	loff_t next_pos;
73 	unsigned char *tempname;
74 	int c1, c2 = 0;
75 	int ret = 0;
76 
77 	hpfs_lock(inode->i_sb);
78 
79 	if (hpfs_sb(inode->i_sb)->sb_chk) {
80 		if (hpfs_chk_sectors(inode->i_sb, inode->i_ino, 1, "dir_fnode")) {
81 			ret = -EFSERROR;
82 			goto out;
83 		}
84 		if (hpfs_chk_sectors(inode->i_sb, hpfs_inode->i_dno, 4, "dir_dnode")) {
85 			ret = -EFSERROR;
86 			goto out;
87 		}
88 	}
89 	if (hpfs_sb(inode->i_sb)->sb_chk >= 2) {
90 		struct buffer_head *bh;
91 		struct fnode *fno;
92 		int e = 0;
93 		if (!(fno = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) {
94 			ret = -EIOERROR;
95 			goto out;
96 		}
97 		if (!fnode_is_dir(fno)) {
98 			e = 1;
99 			hpfs_error(inode->i_sb, "not a directory, fnode %08lx",
100 					(unsigned long)inode->i_ino);
101 		}
102 		if (hpfs_inode->i_dno != le32_to_cpu(fno->u.external[0].disk_secno)) {
103 			e = 1;
104 			hpfs_error(inode->i_sb, "corrupted inode: i_dno == %08x, fnode -> dnode == %08x", hpfs_inode->i_dno, le32_to_cpu(fno->u.external[0].disk_secno));
105 		}
106 		brelse(bh);
107 		if (e) {
108 			ret = -EFSERROR;
109 			goto out;
110 		}
111 	}
112 	lc = hpfs_sb(inode->i_sb)->sb_lowercase;
113 	if (ctx->pos == 12) { /* diff -r requires this (note, that diff -r */
114 		ctx->pos = 13; /* also fails on msdos filesystem in 2.0) */
115 		goto out;
116 	}
117 	if (ctx->pos == 13) {
118 		ret = -ENOENT;
119 		goto out;
120 	}
121 
122 	while (1) {
123 		again:
124 		/* This won't work when cycle is longer than number of dirents
125 		   accepted by filldir, but what can I do?
126 		   maybe killall -9 ls helps */
127 		if (hpfs_sb(inode->i_sb)->sb_chk)
128 			if (hpfs_stop_cycles(inode->i_sb, ctx->pos, &c1, &c2, "hpfs_readdir")) {
129 				ret = -EFSERROR;
130 				goto out;
131 			}
132 		if (ctx->pos == 12)
133 			goto out;
134 		if (ctx->pos == 3 || ctx->pos == 4 || ctx->pos == 5) {
135 			pr_err("pos==%d\n", (int)ctx->pos);
136 			goto out;
137 		}
138 		if (ctx->pos == 0) {
139 			if (!dir_emit_dot(file, ctx))
140 				goto out;
141 			ctx->pos = 11;
142 		}
143 		if (ctx->pos == 11) {
144 			if (!dir_emit(ctx, "..", 2, hpfs_inode->i_parent_dir, DT_DIR))
145 				goto out;
146 			ctx->pos = 1;
147 		}
148 		if (ctx->pos == 1) {
149 			ret = hpfs_add_pos(inode, &file->f_pos);
150 			if (unlikely(ret < 0))
151 				goto out;
152 			ctx->pos = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, hpfs_inode->i_dno) << 4) + 1;
153 		}
154 		next_pos = ctx->pos;
155 		if (!(de = map_pos_dirent(inode, &next_pos, &qbh))) {
156 			ctx->pos = next_pos;
157 			ret = -EIOERROR;
158 			goto out;
159 		}
160 		if (de->first || de->last) {
161 			if (hpfs_sb(inode->i_sb)->sb_chk) {
162 				if (de->first && !de->last && (de->namelen != 2
163 				    || de ->name[0] != 1 || de->name[1] != 1))
164 					hpfs_error(inode->i_sb, "hpfs_readdir: bad ^A^A entry; pos = %08lx", (unsigned long)ctx->pos);
165 				if (de->last && (de->namelen != 1 || de ->name[0] != 255))
166 					hpfs_error(inode->i_sb, "hpfs_readdir: bad \\377 entry; pos = %08lx", (unsigned long)ctx->pos);
167 			}
168 			hpfs_brelse4(&qbh);
169 			ctx->pos = next_pos;
170 			goto again;
171 		}
172 		tempname = hpfs_translate_name(inode->i_sb, de->name, de->namelen, lc, de->not_8x3);
173 		if (!dir_emit(ctx, tempname, de->namelen, le32_to_cpu(de->fnode), DT_UNKNOWN)) {
174 			if (tempname != de->name) kfree(tempname);
175 			hpfs_brelse4(&qbh);
176 			goto out;
177 		}
178 		ctx->pos = next_pos;
179 		if (tempname != de->name) kfree(tempname);
180 		hpfs_brelse4(&qbh);
181 	}
182 out:
183 	hpfs_unlock(inode->i_sb);
184 	return ret;
185 }
186 
187 /*
188  * lookup.  Search the specified directory for the specified name, set
189  * *result to the corresponding inode.
190  *
191  * lookup uses the inode number to tell read_inode whether it is reading
192  * the inode of a directory or a file -- file ino's are odd, directory
193  * ino's are even.  read_inode avoids i/o for file inodes; everything
194  * needed is up here in the directory.  (And file fnodes are out in
195  * the boondocks.)
196  *
197  *    - M.P.: this is over, sometimes we've got to read file's fnode for eas
198  *	      inode numbers are just fnode sector numbers; iget lock is used
199  *	      to tell read_inode to read fnode or not.
200  */
201 
202 struct dentry *hpfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
203 {
204 	const unsigned char *name = dentry->d_name.name;
205 	unsigned len = dentry->d_name.len;
206 	struct quad_buffer_head qbh;
207 	struct hpfs_dirent *de;
208 	ino_t ino;
209 	int err;
210 	struct inode *result = NULL;
211 	struct hpfs_inode_info *hpfs_result;
212 
213 	hpfs_lock(dir->i_sb);
214 	if ((err = hpfs_chk_name(name, &len))) {
215 		if (err == -ENAMETOOLONG) {
216 			hpfs_unlock(dir->i_sb);
217 			return ERR_PTR(-ENAMETOOLONG);
218 		}
219 		goto end_add;
220 	}
221 
222 	/*
223 	 * '.' and '..' will never be passed here.
224 	 */
225 
226 	de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, NULL, &qbh);
227 
228 	/*
229 	 * This is not really a bailout, just means file not found.
230 	 */
231 
232 	if (!de) goto end;
233 
234 	/*
235 	 * Get inode number, what we're after.
236 	 */
237 
238 	ino = le32_to_cpu(de->fnode);
239 
240 	/*
241 	 * Go find or make an inode.
242 	 */
243 
244 	result = iget_locked(dir->i_sb, ino);
245 	if (!result) {
246 		hpfs_error(dir->i_sb, "hpfs_lookup: can't get inode");
247 		result = ERR_PTR(-ENOMEM);
248 		goto bail1;
249 	}
250 	if (result->i_state & I_NEW) {
251 		hpfs_init_inode(result);
252 		if (de->directory)
253 			hpfs_read_inode(result);
254 		else if (le32_to_cpu(de->ea_size) && hpfs_sb(dir->i_sb)->sb_eas)
255 			hpfs_read_inode(result);
256 		else {
257 			result->i_mode |= S_IFREG;
258 			result->i_mode &= ~0111;
259 			result->i_op = &hpfs_file_iops;
260 			result->i_fop = &hpfs_file_ops;
261 			set_nlink(result, 1);
262 		}
263 		unlock_new_inode(result);
264 	}
265 	hpfs_result = hpfs_i(result);
266 	if (!de->directory) hpfs_result->i_parent_dir = dir->i_ino;
267 
268 	if (de->has_acl || de->has_xtd_perm) if (!sb_rdonly(dir->i_sb)) {
269 		hpfs_error(result->i_sb, "ACLs or XPERM found. This is probably HPFS386. This driver doesn't support it now. Send me some info on these structures");
270 		iput(result);
271 		result = ERR_PTR(-EINVAL);
272 		goto bail1;
273 	}
274 
275 	/*
276 	 * Fill in the info from the directory if this is a newly created
277 	 * inode.
278 	 */
279 
280 	if (!result->i_ctime.tv_sec) {
281 		if (!(result->i_ctime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->creation_date))))
282 			result->i_ctime.tv_sec = 1;
283 		result->i_ctime.tv_nsec = 0;
284 		result->i_mtime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->write_date));
285 		result->i_mtime.tv_nsec = 0;
286 		result->i_atime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->read_date));
287 		result->i_atime.tv_nsec = 0;
288 		hpfs_result->i_ea_size = le32_to_cpu(de->ea_size);
289 		if (!hpfs_result->i_ea_mode && de->read_only)
290 			result->i_mode &= ~0222;
291 		if (!de->directory) {
292 			if (result->i_size == -1) {
293 				result->i_size = le32_to_cpu(de->file_size);
294 				result->i_data.a_ops = &hpfs_aops;
295 				hpfs_i(result)->mmu_private = result->i_size;
296 			/*
297 			 * i_blocks should count the fnode and any anodes.
298 			 * We count 1 for the fnode and don't bother about
299 			 * anodes -- the disk heads are on the directory band
300 			 * and we want them to stay there.
301 			 */
302 				result->i_blocks = 1 + ((result->i_size + 511) >> 9);
303 			}
304 		}
305 	}
306 
307 bail1:
308 	hpfs_brelse4(&qbh);
309 
310 	/*
311 	 * Made it.
312 	 */
313 
314 end:
315 end_add:
316 	hpfs_unlock(dir->i_sb);
317 	return d_splice_alias(result, dentry);
318 }
319 
320 const struct file_operations hpfs_dir_ops =
321 {
322 	.llseek		= hpfs_dir_lseek,
323 	.read		= generic_read_dir,
324 	.iterate_shared	= hpfs_readdir,
325 	.release	= hpfs_dir_release,
326 	.fsync		= hpfs_file_fsync,
327 	.unlocked_ioctl	= hpfs_ioctl,
328 };
329