aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/pending-4.4/052-02-ubifs-Implement-RENAME_WHITEOUT.patch
blob: c2ec904939872a55d875bcfc41c1252d8991f902 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
From: Richard Weinberger <richard@nod.at>
Date: Tue, 13 Sep 2016 16:18:56 +0200
Subject: [PATCH] ubifs: Implement RENAME_WHITEOUT

Adds RENAME_WHITEOUT support to UBIFS, we implement
it in the same way as ext4 and xfs do.
For an overview of other ways to implement it please
refere to commit 7dcf5c3e4527 ("xfs: add RENAME_WHITEOUT support").

Signed-off-by: Richard Weinberger <richard@nod.at>
---

--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -301,8 +301,8 @@ out_budg:
 	return err;
 }
 
-static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
-			 umode_t mode)
+static int do_tmpfile(struct inode *dir, struct dentry *dentry,
+		      umode_t mode, struct inode **whiteout)
 {
 	struct inode *inode;
 	struct ubifs_info *c = dir->i_sb->s_fs_info;
@@ -336,14 +336,27 @@ static int ubifs_tmpfile(struct inode *d
 	}
 	ui = ubifs_inode(inode);
 
+	if (whiteout) {
+		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
+		ubifs_assert(inode->i_op == &ubifs_file_inode_operations);
+	}
+
 	err = ubifs_init_security(dir, inode, &dentry->d_name);
 	if (err)
 		goto out_inode;
 
 	mutex_lock(&ui->ui_mutex);
 	insert_inode_hash(inode);
-	d_tmpfile(dentry, inode);
+
+	if (whiteout) {
+		mark_inode_dirty(inode);
+		drop_nlink(inode);
+		*whiteout = inode;
+	} else {
+		d_tmpfile(dentry, inode);
+	}
 	ubifs_assert(ui->dirty);
+
 	instantiated = 1;
 	mutex_unlock(&ui->ui_mutex);
 
@@ -371,6 +384,12 @@ out_budg:
 	return err;
 }
 
+static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
+			 umode_t mode)
+{
+	return do_tmpfile(dir, dentry, mode, NULL);
+}
+
 /**
  * vfs_dent_type - get VFS directory entry type.
  * @type: UBIFS directory entry type
@@ -1003,37 +1022,43 @@ out_budg:
 }
 
 /**
- * lock_3_inodes - a wrapper for locking three UBIFS inodes.
+ * lock_4_inodes - a wrapper for locking three UBIFS inodes.
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
+ * @inode4: fouth inode
  *
  * This function is used for 'ubifs_rename()' and @inode1 may be the same as
- * @inode2 whereas @inode3 may be %NULL.
+ * @inode2 whereas @inode3 and @inode4 may be %NULL.
  *
  * We do not implement any tricks to guarantee strict lock ordering, because
  * VFS has already done it for us on the @i_mutex. So this is just a simple
  * wrapper function.
  */
-static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
-			  struct inode *inode3)
+static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
+			  struct inode *inode3, struct inode *inode4)
 {
 	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
 	if (inode2 != inode1)
 		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
 	if (inode3)
 		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
+	if (inode4)
+		mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
 }
 
 /**
- * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
+ * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
+ * @inode4: fouth inode
  */
-static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
-			    struct inode *inode3)
+static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
+			    struct inode *inode3, struct inode *inode4)
 {
+	if (inode4)
+		mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
 	if (inode3)
 		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
 	if (inode1 != inode2)
@@ -1042,12 +1067,15 @@ static void unlock_3_inodes(struct inode
 }
 
 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
-			struct inode *new_dir, struct dentry *new_dentry)
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
 {
 	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
 	struct inode *old_inode = d_inode(old_dentry);
 	struct inode *new_inode = d_inode(new_dentry);
+	struct inode *whiteout = NULL;
 	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
+	struct ubifs_inode *whiteout_ui = NULL;
 	int err, release, sync = 0, move = (new_dir != old_dir);
 	int is_dir = S_ISDIR(old_inode->i_mode);
 	int unlink = !!new_inode;
@@ -1069,9 +1097,13 @@ static int ubifs_rename(struct inode *ol
 	 * separately.
 	 */
 
-	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu",
+	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
 		old_dentry, old_inode->i_ino, old_dir->i_ino,
-		new_dentry, new_dir->i_ino);
+		new_dentry, new_dir->i_ino, flags);
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT))
+		return -EINVAL;
+
 	ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
 	ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
 	if (unlink)
@@ -1093,7 +1125,32 @@ static int ubifs_rename(struct inode *ol
 		return err;
 	}
 
-	lock_3_inodes(old_dir, new_dir, new_inode);
+	if (flags & RENAME_WHITEOUT) {
+		union ubifs_dev_desc *dev = NULL;
+
+		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+		if (!dev) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			return -ENOMEM;
+		}
+
+		err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
+		if (err) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			kfree(dev);
+			return err;
+		}
+
+		whiteout->i_state |= I_LINKABLE;
+		whiteout_ui = ubifs_inode(whiteout);
+		whiteout_ui->data = dev;
+		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
+		ubifs_assert(!whiteout_ui->dirty);
+	}
+
+	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 
 	/*
 	 * Like most other Unix systems, set the @i_ctime for inodes on a
@@ -1163,12 +1220,34 @@ static int ubifs_rename(struct inode *ol
 		if (unlink && IS_SYNC(new_inode))
 			sync = 1;
 	}
-	err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
+
+	if (whiteout) {
+		struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
+				.dirtied_ino_d = \
+				ALIGN(ubifs_inode(whiteout)->data_len, 8) };
+
+		err = ubifs_budget_space(c, &wht_req);
+		if (err) {
+			ubifs_release_budget(c, &req);
+			ubifs_release_budget(c, &ino_req);
+			kfree(whiteout_ui->data);
+			whiteout_ui->data_len = 0;
+			iput(whiteout);
+			return err;
+		}
+
+		inc_nlink(whiteout);
+		mark_inode_dirty(whiteout);
+		whiteout->i_state &= ~I_LINKABLE;
+		iput(whiteout);
+	}
+
+	err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, whiteout,
 			       sync);
 	if (err)
 		goto out_cancel;
 
-	unlock_3_inodes(old_dir, new_dir, new_inode);
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 	ubifs_release_budget(c, &req);
 
 	mutex_lock(&old_inode_ui->ui_mutex);
@@ -1201,7 +1280,11 @@ out_cancel:
 				inc_nlink(old_dir);
 		}
 	}
-	unlock_3_inodes(old_dir, new_dir, new_inode);
+	if (whiteout) {
+		drop_nlink(whiteout);
+		iput(whiteout);
+	}
+	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
 	ubifs_release_budget(c, &ino_req);
 	ubifs_release_budget(c, &req);
 	return err;
@@ -1255,7 +1338,7 @@ const struct inode_operations ubifs_dir_
 	.mkdir       = ubifs_mkdir,
 	.rmdir       = ubifs_rmdir,
 	.mknod       = ubifs_mknod,
-	.rename      = ubifs_rename,
+	.rename2     = ubifs_rename,
 	.setattr     = ubifs_setattr,
 	.getattr     = ubifs_getattr,
 	.setxattr    = ubifs_setxattr,
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -917,14 +917,15 @@ int ubifs_jnl_delete_inode(struct ubifs_
  * @sync: non-zero if the write-buffer has to be synchronized
  *
  * This function implements the re-name operation which may involve writing up
- * to 3 inodes and 2 directory entries. It marks the written inodes as clean
+ * to 4 inodes and 2 directory entries. It marks the written inodes as clean
  * and returns zero on success. In case of failure, a negative error code is
  * returned.
  */
 int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 		     const struct dentry *old_dentry,
 		     const struct inode *new_dir,
-		     const struct dentry *new_dentry, int sync)
+		     const struct dentry *new_dentry,
+		     const struct inode *whiteout, int sync)
 {
 	void *p;
 	union ubifs_key key;
@@ -980,13 +981,19 @@ int ubifs_jnl_rename(struct ubifs_info *
 	zero_dent_node_unused(dent);
 	ubifs_prep_grp_node(c, dent, dlen1, 0);
 
-	/* Make deletion dent */
 	dent2 = (void *)dent + aligned_dlen1;
 	dent2->ch.node_type = UBIFS_DENT_NODE;
 	dent_key_init_flash(c, &dent2->key, old_dir->i_ino,
 			    &old_dentry->d_name);
-	dent2->inum = 0;
-	dent2->type = DT_UNKNOWN;
+
+	if (whiteout) {
+		dent2->inum = cpu_to_le64(whiteout->i_ino);
+		dent2->type = get_dent_type(whiteout->i_mode);
+	} else {
+		/* Make deletion dent */
+		dent2->inum = 0;
+		dent2->type = DT_UNKNOWN;
+	}
 	dent2->nlen = cpu_to_le16(old_dentry->d_name.len);
 	memcpy(dent2->name, old_dentry->d_name.name, old_dentry->d_name.len);
 	dent2->name[old_dentry->d_name.len] = '\0';
@@ -1035,16 +1042,26 @@ int ubifs_jnl_rename(struct ubifs_info *
 	if (err)
 		goto out_ro;
 
-	err = ubifs_add_dirt(c, lnum, dlen2);
-	if (err)
-		goto out_ro;
-
-	dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
-	err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
-	if (err)
-		goto out_ro;
+	offs += aligned_dlen1;
+	if (whiteout) {
+		dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
+		err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &old_dentry->d_name);
+		if (err)
+			goto out_ro;
+
+		ubifs_delete_orphan(c, whiteout->i_ino);
+	} else {
+		err = ubifs_add_dirt(c, lnum, dlen2);
+		if (err)
+			goto out_ro;
+
+		dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
+		err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
+		if (err)
+			goto out_ro;
+	}
 
-	offs += aligned_dlen1 + aligned_dlen2;
+	offs += aligned_dlen2;
 	if (new_inode) {
 		ino_key_init(c, &key, new_inode->i_ino);
 		err = ubifs_tnc_add(c, &key, lnum, offs, ilen);
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -180,6 +180,7 @@ enum {
 	WB_MUTEX_1 = 0,
 	WB_MUTEX_2 = 1,
 	WB_MUTEX_3 = 2,
+	WB_MUTEX_4 = 3,
 };
 
 /*
@@ -1546,7 +1547,8 @@ int ubifs_jnl_delete_inode(struct ubifs_
 int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
 		     const struct dentry *old_dentry,
 		     const struct inode *new_dir,
-		     const struct dentry *new_dentry, int sync);
+		     const struct dentry *new_dentry,
+		     const struct inode *whiteout, int sync);
 int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
 		       loff_t old_size, loff_t new_size);
 int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,