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
|
From: Richard Weinberger <richard@nod.at>
Date: Tue, 13 Sep 2016 16:18:57 +0200
Subject: [PATCH] ubifs: Implement RENAME_EXCHANGE
Adds RENAME_EXCHANGE to UBIFS, the operation itself
is completely disjunct from a regular rename() that's
why we dispatch very early in ubifs_reaname().
RENAME_EXCHANGE used by the renameat2() system call
allows the caller to exchange two paths atomically.
Both paths have to exist and have to be on the same
filesystem.
Signed-off-by: Richard Weinberger <richard@nod.at>
---
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1101,11 +1101,6 @@ static int ubifs_rename(struct inode *ol
old_dentry, old_inode->i_ino, old_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)
ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
@@ -1290,6 +1285,64 @@ out_cancel:
return err;
}
+static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct ubifs_info *c = old_dir->i_sb->s_fs_info;
+ struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
+ .dirtied_ino = 2 };
+ int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
+ struct inode *fst_inode = d_inode(old_dentry);
+ struct inode *snd_inode = d_inode(new_dentry);
+ struct timespec time;
+ int err;
+
+ ubifs_assert(fst_inode && snd_inode);
+
+ lock_4_inodes(old_dir, new_dir, NULL, NULL);
+
+ time = ubifs_current_time(old_dir);
+ fst_inode->i_ctime = time;
+ snd_inode->i_ctime = time;
+ old_dir->i_mtime = old_dir->i_ctime = time;
+ new_dir->i_mtime = new_dir->i_ctime = time;
+
+ if (old_dir != new_dir) {
+ if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
+ inc_nlink(new_dir);
+ drop_nlink(old_dir);
+ }
+ else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
+ drop_nlink(new_dir);
+ inc_nlink(old_dir);
+ }
+ }
+
+ err = ubifs_jnl_xrename(c, old_dir, old_dentry, new_dir, new_dentry,
+ sync);
+
+ unlock_4_inodes(old_dir, new_dir, NULL, NULL);
+ ubifs_release_budget(c, &req);
+
+ return err;
+}
+
+static int ubifs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
+ return -EINVAL;
+
+ ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
+
+ if (flags & RENAME_EXCHANGE)
+ return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
+
+ return ubifs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
+}
+
int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
@@ -1338,7 +1391,7 @@ const struct inode_operations ubifs_dir_
.mkdir = ubifs_mkdir,
.rmdir = ubifs_rmdir,
.mknod = ubifs_mknod,
- .rename2 = ubifs_rename,
+ .rename2 = ubifs_rename2,
.setattr = ubifs_setattr,
.getattr = ubifs_getattr,
.setxattr = ubifs_setxattr,
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -908,6 +908,147 @@ int ubifs_jnl_delete_inode(struct ubifs_
}
/**
+ * ubifs_jnl_xrename - cross rename two directory entries.
+ * @c: UBIFS file-system description object
+ * @fst_dir: parent inode of 1st directory entry to exchange
+ * @fst_dentry: 1st directory entry to exchange
+ * @snd_dir: parent inode of 2nd directory entry to exchange
+ * @snd_dentry: 2nd directory entry to exchange
+ * @sync: non-zero if the write-buffer has to be synchronized
+ *
+ * This function implements the cross rename operation which may involve
+ * writing 2 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_xrename(struct ubifs_info *c, const struct inode *fst_dir,
+ const struct dentry *fst_dentry,
+ const struct inode *snd_dir,
+ const struct dentry *snd_dentry, int sync)
+{
+ union ubifs_key key;
+ struct ubifs_dent_node *dent1, *dent2;
+ int err, dlen1, dlen2, lnum, offs, len, plen = UBIFS_INO_NODE_SZ;
+ int aligned_dlen1, aligned_dlen2;
+ int twoparents = (fst_dir != snd_dir);
+ const struct inode *fst_inode = d_inode(fst_dentry);
+ const struct inode *snd_inode = d_inode(snd_dentry);
+ void *p;
+
+ dbg_jnl("dent '%pd' in dir ino %lu between dent '%pd' in dir ino %lu",
+ fst_dentry, fst_dir->i_ino, snd_dentry, snd_dir->i_ino);
+
+ ubifs_assert(ubifs_inode(fst_dir)->data_len == 0);
+ ubifs_assert(ubifs_inode(snd_dir)->data_len == 0);
+ ubifs_assert(mutex_is_locked(&ubifs_inode(fst_dir)->ui_mutex));
+ ubifs_assert(mutex_is_locked(&ubifs_inode(snd_dir)->ui_mutex));
+
+ dlen1 = UBIFS_DENT_NODE_SZ + snd_dentry->d_name.len + 1;
+ dlen2 = UBIFS_DENT_NODE_SZ + fst_dentry->d_name.len + 1;
+ aligned_dlen1 = ALIGN(dlen1, 8);
+ aligned_dlen2 = ALIGN(dlen2, 8);
+
+ len = aligned_dlen1 + aligned_dlen2 + ALIGN(plen, 8);
+ if (twoparents)
+ len += plen;
+
+ dent1 = kmalloc(len, GFP_NOFS);
+ if (!dent1)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, len);
+ if (err)
+ goto out_free;
+
+ /* Make new dent for 1st entry */
+ dent1->ch.node_type = UBIFS_DENT_NODE;
+ dent_key_init_flash(c, &dent1->key, snd_dir->i_ino, &snd_dentry->d_name);
+ dent1->inum = cpu_to_le64(fst_inode->i_ino);
+ dent1->type = get_dent_type(fst_inode->i_mode);
+ dent1->nlen = cpu_to_le16(snd_dentry->d_name.len);
+ memcpy(dent1->name, snd_dentry->d_name.name, snd_dentry->d_name.len);
+ dent1->name[snd_dentry->d_name.len] = '\0';
+ zero_dent_node_unused(dent1);
+ ubifs_prep_grp_node(c, dent1, dlen1, 0);
+
+ /* Make new dent for 2nd entry */
+ dent2 = (void *)dent1 + aligned_dlen1;
+ dent2->ch.node_type = UBIFS_DENT_NODE;
+ dent_key_init_flash(c, &dent2->key, fst_dir->i_ino, &fst_dentry->d_name);
+ dent2->inum = cpu_to_le64(snd_inode->i_ino);
+ dent2->type = get_dent_type(snd_inode->i_mode);
+ dent2->nlen = cpu_to_le16(fst_dentry->d_name.len);
+ memcpy(dent2->name, fst_dentry->d_name.name, fst_dentry->d_name.len);
+ dent2->name[fst_dentry->d_name.len] = '\0';
+ zero_dent_node_unused(dent2);
+ ubifs_prep_grp_node(c, dent2, dlen2, 0);
+
+ p = (void *)dent2 + aligned_dlen2;
+ if (!twoparents)
+ pack_inode(c, p, fst_dir, 1);
+ else {
+ pack_inode(c, p, fst_dir, 0);
+ p += ALIGN(plen, 8);
+ pack_inode(c, p, snd_dir, 1);
+ }
+
+ err = write_head(c, BASEHD, dent1, len, &lnum, &offs, sync);
+ if (err)
+ goto out_release;
+ if (!sync) {
+ struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
+
+ ubifs_wbuf_add_ino_nolock(wbuf, fst_dir->i_ino);
+ ubifs_wbuf_add_ino_nolock(wbuf, snd_dir->i_ino);
+ }
+ release_head(c, BASEHD);
+
+ dent_key_init(c, &key, snd_dir->i_ino, &snd_dentry->d_name);
+ err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &snd_dentry->d_name);
+ if (err)
+ goto out_ro;
+
+ offs += aligned_dlen1;
+ dent_key_init(c, &key, fst_dir->i_ino, &fst_dentry->d_name);
+ err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, &fst_dentry->d_name);
+ if (err)
+ goto out_ro;
+
+ offs += aligned_dlen2;
+
+ ino_key_init(c, &key, fst_dir->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+ if (err)
+ goto out_ro;
+
+ if (twoparents) {
+ offs += ALIGN(plen, 8);
+ ino_key_init(c, &key, snd_dir->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+ if (err)
+ goto out_ro;
+ }
+
+ finish_reservation(c);
+
+ mark_inode_clean(c, ubifs_inode(fst_dir));
+ if (twoparents)
+ mark_inode_clean(c, ubifs_inode(snd_dir));
+ kfree(dent1);
+ return 0;
+
+out_release:
+ release_head(c, BASEHD);
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+out_free:
+ kfree(dent1);
+ return err;
+}
+
+/**
* ubifs_jnl_rename - rename a directory entry.
* @c: UBIFS file-system description object
* @old_dir: parent inode of directory entry to rename
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1544,6 +1544,10 @@ int ubifs_jnl_write_data(struct ubifs_in
const union ubifs_key *key, const void *buf, int len);
int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
+int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir,
+ const struct dentry *fst_dentry,
+ const struct inode *snd_dir,
+ const struct dentry *snd_dentry, int sync);
int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
const struct dentry *old_dentry,
const struct inode *new_dir,
|
