+static inline struct semaphore * lock_sem(struct inode *dir, struct qstr *name)
+{
+ if (IS_PDIROPS(dir)) {
+ struct super_block *sb;
+ /* name->hash expected to be already calculated */
+ sb = dir->i_sb;
+ BUG_ON(sb->s_pdirops_sems == NULL);
+ return sb->s_pdirops_sems + name->hash % sb->s_pdirops_size;
+ }
+ return &dir->i_sem;
+}
+
+static inline void lock_dir(struct inode *dir, struct qstr *name)
+{
+ down(lock_sem(dir, name));
+}
+
@@ -1182,12 +1204,26 @@
/*
* p1 and p2 should be directories on the same fs.
*/
-struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
+struct dentry *lock_rename(struct dentry *p1, struct qstr *n1,
+ struct dentry *p2, struct qstr *n2)
{
struct dentry *p;
if (p1 == p2) {
- down(&p1->d_inode->i_sem);
+ if (IS_PDIROPS(p1->d_inode)) {
+ unsigned int h1, h2;
+ h1 = n1->hash % p1->d_inode->i_sb->s_pdirops_size;
+ h2 = n2->hash % p2->d_inode->i_sb->s_pdirops_size;
+ if (h1 < h2) {
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
+ } else if (h1 > h2) {
+ lock_dir(p2->d_inode, n2);
+ lock_dir(p1->d_inode, n1);
+ } else
+ lock_dir(p1->d_inode, n1);
+ } else
+ down(&p1->d_inode->i_sem);
return NULL;
}
@@ -1195,31 +1231,35 @@
for (p = p1; p->d_parent != p; p = p->d_parent) {
if (p->d_parent == p2) {
- down(&p2->d_inode->i_sem);
- down(&p1->d_inode->i_sem);
+ lock_dir(p2->d_inode, n2);
+ lock_dir(p1->d_inode, n1);
return p;
}
}
for (p = p2; p->d_parent != p; p = p->d_parent) {
if (p->d_parent == p1) {
- down(&p1->d_inode->i_sem);
- down(&p2->d_inode->i_sem);
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
return p;
}
}
- down(&p1->d_inode->i_sem);
- down(&p2->d_inode->i_sem);
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
return NULL;
}