On Mon, Jul 18, 2011 at 05:45:02PM +0100, Al Viro wrote:
> lookup-by-hand code in there. Or with calculating hash - also done
> by lookup_one_len(), TYVM... If anything, I'd start with this as the first
> approximation and probably looked into simplifying the loop a bit more -
> lookup_one_len() doesn't need name component to be NUL-terminated...
Fix cifs_get_root()
Add missing ->i_mutex, convert to lookup_one_len() instead of
(broken) open-coded analog, cope with getting something like
a//b as relative pathname. Simplify the hell out of it, while
we are there...
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 112fbd96..cbbb55e 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -35,6 +35,7 @@
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
+#include <linux/namei.h>
#include <net/ipv6.h>
#include "cifsfs.h"
#include "cifspdu.h"
@@ -542,14 +543,12 @@ static const struct super_operations cifs_super_ops = {
static struct dentry *
cifs_get_root(struct smb_vol *vol, struct super_block *sb)
{
- int xid, rc;
- struct inode *inode;
- struct qstr name;
- struct dentry *dparent = NULL, *dchild = NULL, *alias;
+ struct dentry *dentry;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
- unsigned int i, full_len, len;
- char *full_path = NULL, *pstart;
+ char *full_path = NULL;
+ char *s, *p;
char sep;
+ int xid;
full_path = cifs_build_path_to_root(vol, cifs_sb,
cifs_sb_master_tcon(cifs_sb));
@@ -560,73 +559,32 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb)
xid = GetXid();
sep = CIFS_DIR_SEP(cifs_sb);
- dparent = dget(sb->s_root);
- full_len = strlen(full_path);
- full_path[full_len] = sep;
- pstart = full_path + 1;
-
- for (i = 1, len = 0; i <= full_len; i++) {
- if (full_path[i] != sep || !len) {
- len++;
- continue;
- }
-
- full_path[i] = 0;
- cFYI(1, "get dentry for %s", pstart);
-
- name.name = pstart;
- name.len = len;
- name.hash = full_name_hash(pstart, len);
- dchild = d_lookup(dparent, &name);
- if (dchild == NULL) {
- cFYI(1, "not exists");
- dchild = d_alloc(dparent, &name);
- if (dchild == NULL) {
- dput(dparent);
- dparent = ERR_PTR(-ENOMEM);
- goto out;
- }
- }
-
- cFYI(1, "get inode");
- if (dchild->d_inode == NULL) {
- cFYI(1, "not exists");
- inode = NULL;
- if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
- rc = cifs_get_inode_info_unix(&inode, full_path,
- sb, xid);
- else
- rc = cifs_get_inode_info(&inode, full_path,
- NULL, sb, xid, NULL);
- if (rc) {
- dput(dchild);
- dput(dparent);
- dparent = ERR_PTR(rc);
- goto out;
- }
- alias = d_materialise_unique(dchild, inode);
- if (alias != NULL) {
- dput(dchild);
- if (IS_ERR(alias)) {
- dput(dparent);
- dparent = ERR_PTR(-EINVAL); /* XXX */
- goto out;
- }
- dchild = alias;
- }
- }
- cFYI(1, "parent %p, child %p", dparent, dchild);
-
- dput(dparent);
- dparent = dchild;
- len = 0;
- pstart = full_path + i + 1;
- full_path[i] = sep;
- }
-out:
+ dentry = dget(sb->s_root);
+ p = s = full_path;
+
+ do {
+ struct inode *dir = dentry->d_inode;
+ struct dentry *child;
+
+ /* skip separators */
+ while (*s == sep)
+ s++;
+ if (!*s)
+ break;
+ p = s++;
+ /* next separator */
+ while (*s && *s != sep)
+ s++;
+
+ mutex_lock(&dir->i_mutex);
+ child = lookup_one_len(p, dentry, s - p);
+ mutex_unlock(&dir->i_mutex);
+ dput(dentry);
+ dentry = child;
+ } while (!IS_ERR(dentry));
_FreeXid(xid);
kfree(full_path);
- return dparent;
+ return dentry;
}
static int cifs_set_super(struct super_block *sb, void *data)
--
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