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
|
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -34,6 +34,9 @@ static int jffs2_mknod (struct inode *,s
static int jffs2_rename (struct inode *, struct dentry *,
struct inode *, struct dentry *);
+static int jffs2_whiteout (struct inode *, struct dentry *, struct dentry *);
+static int jffs2_fallthru (struct inode *, struct dentry *);
+
const struct file_operations jffs2_dir_operations =
{
.read = generic_read_dir,
@@ -55,6 +58,8 @@ const struct inode_operations jffs2_dir_
.rmdir = jffs2_rmdir,
.mknod = jffs2_mknod,
.rename = jffs2_rename,
+ .fallthru = jffs2_fallthru,
+ .whiteout = jffs2_whiteout,
.check_acl = jffs2_check_acl,
.setattr = jffs2_setattr,
.setxattr = jffs2_setxattr,
@@ -98,8 +103,21 @@ static struct dentry *jffs2_lookup(struc
fd = fd_list;
}
}
- if (fd)
- ino = fd->ino;
+ if (fd) {
+ spin_lock(&target->d_lock);
+ switch(fd->type) {
+ case DT_WHT:
+ target->d_flags |= DCACHE_WHITEOUT;
+ break;
+ case DT_UNKNOWN:
+ target->d_flags |= DCACHE_FALLTHRU;
+ break;
+ default:
+ ino = fd->ino;
+ break;
+ }
+ spin_unlock(&target->d_lock);
+ }
mutex_unlock(&dir_f->sem);
if (ino) {
inode = jffs2_iget(dir_i->i_sb, ino);
@@ -155,7 +173,9 @@ static int jffs2_readdir(struct file *fi
fd->name, fd->ino, fd->type, curofs, offset));
continue;
}
- if (!fd->ino) {
+ if (fd->type == DT_UNKNOWN)
+ fd->ino = 100; /* XXX: arbitrary */
+ else if (!fd->ino && (fd->type != DT_WHT)) {
D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name));
offset++;
continue;
@@ -498,6 +518,11 @@ static int jffs2_mkdir (struct inode *di
return PTR_ERR(inode);
}
+ if (dentry->d_flags & DCACHE_WHITEOUT) {
+ inode->i_flags |= S_OPAQUE;
+ ri->flags = cpu_to_je16(JFFS2_INO_FLAG_OPAQUE);
+ }
+
inode->i_op = &jffs2_dir_inode_operations;
inode->i_fop = &jffs2_dir_operations;
@@ -779,6 +804,82 @@ static int jffs2_mknod (struct inode *di
return 0;
}
+static int jffs2_fallthru (struct inode *dir, struct dentry *dentry)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb);
+ uint32_t now;
+ int ret;
+
+ now = get_seconds();
+ ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_UNKNOWN,
+ dentry->d_name.name, dentry->d_name.len, now);
+ if (ret)
+ return ret;
+
+ d_instantiate(dentry, NULL);
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_FALLTHRU;
+ spin_unlock(&dentry->d_lock);
+
+ return 0;
+}
+
+static int jffs2_whiteout (struct inode *dir, struct dentry *old_dentry,
+ struct dentry *new_dentry)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb);
+ struct jffs2_inode_info *victim_f = NULL;
+ uint32_t now;
+ int ret;
+
+ /* If it's a directory, then check whether it is really empty
+ */
+ if (new_dentry->d_inode) {
+ victim_f = JFFS2_INODE_INFO(old_dentry->d_inode);
+ if (S_ISDIR(old_dentry->d_inode->i_mode)) {
+ struct jffs2_full_dirent *fd;
+
+ mutex_lock(&victim_f->sem);
+ for (fd = victim_f->dents; fd; fd = fd->next) {
+ if (fd->ino) {
+ mutex_unlock(&victim_f->sem);
+ return -ENOTEMPTY;
+ }
+ }
+ mutex_unlock(&victim_f->sem);
+ }
+ }
+
+ now = get_seconds();
+ ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_WHT,
+ new_dentry->d_name.name, new_dentry->d_name.len, now);
+ if (ret)
+ return ret;
+
+ spin_lock(&new_dentry->d_lock);
+ new_dentry->d_flags &= ~DCACHE_FALLTHRU;
+ new_dentry->d_flags |= DCACHE_WHITEOUT;
+ spin_unlock(&new_dentry->d_lock);
+ d_add(new_dentry, NULL);
+
+ if (victim_f) {
+ /* There was a victim. Kill it off nicely */
+ drop_nlink(old_dentry->d_inode);
+ /* Don't oops if the victim was a dirent pointing to an
+ inode which didn't exist. */
+ if (victim_f->inocache) {
+ mutex_lock(&victim_f->sem);
+ if (S_ISDIR(old_dentry->d_inode->i_mode))
+ victim_f->inocache->pino_nlink = 0;
+ else
+ victim_f->inocache->pino_nlink--;
+ mutex_unlock(&victim_f->sem);
+ }
+ }
+
+ return 0;
+}
+
static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
struct inode *new_dir_i, struct dentry *new_dentry)
{
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -301,6 +301,10 @@ struct inode *jffs2_iget(struct super_bl
inode->i_op = &jffs2_dir_inode_operations;
inode->i_fop = &jffs2_dir_operations;
+
+ if (je16_to_cpu(latest_node.flags) & JFFS2_INO_FLAG_OPAQUE)
+ inode->i_flags |= S_OPAQUE;
+
break;
}
case S_IFREG:
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -172,7 +172,7 @@ static int jffs2_fill_super(struct super
sb->s_op = &jffs2_super_operations;
sb->s_export_op = &jffs2_export_ops;
- sb->s_flags = sb->s_flags | MS_NOATIME;
+ sb->s_flags = sb->s_flags | MS_NOATIME | MS_WHITEOUT;
sb->s_xattr = jffs2_xattr_handlers;
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
sb->s_flags |= MS_POSIXACL;
--- a/include/linux/jffs2.h
+++ b/include/linux/jffs2.h
@@ -87,6 +87,8 @@
#define JFFS2_INO_FLAG_USERCOMPR 2 /* User has requested a specific
compression type */
+#define JFFS2_INO_FLAG_OPAQUE 4 /* Directory is opaque (for union mounts) */
+
/* These can go once we've made sure we've caught all uses without
byteswapping */
|
