[PATCH vfs-2.6 6/6] vfs: add LOOKUP_RENAME_TARGET intent

[linux-2.6-omap-h63xx.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 4ea63ed5e79100d991e5f25656a263b04a29e611..9e2a534383d9f3c26780e4ae937d3b52df16cfc9 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1106,6 +1106,15 @@ int path_lookup(const char *name, unsigned int flags,
        return do_path_lookup(AT_FDCWD, name, flags, nd);
 }
 
+int kern_path(const char *name, unsigned int flags, struct path *path)
+{
+       struct nameidata nd;
+       int res = do_path_lookup(AT_FDCWD, name, flags, &nd);
+       if (!res)
+               *path = nd.path;
+       return res;
+}
+
 /**
  * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
  * @dentry:  pointer to dentry of the base directory
@@ -1138,9 +1147,16 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 
 }
 
-static int __path_lookup_intent_open(int dfd, const char *name,
-               unsigned int lookup_flags, struct nameidata *nd,
-               int open_flags, int create_mode)
+/**
+ * path_lookup_open - lookup a file path with open intent
+ * @dfd: the directory to use as base, or AT_FDCWD
+ * @name: pointer to file name
+ * @lookup_flags: lookup intent flags
+ * @nd: pointer to nameidata
+ * @open_flags: open intent flags
+ */
+int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags,
+               struct nameidata *nd, int open_flags)
 {
        struct file *filp = get_empty_filp();
        int err;
@@ -1149,7 +1165,7 @@ static int __path_lookup_intent_open(int dfd, const char *name,
                return -ENFILE;
        nd->intent.open.file = filp;
        nd->intent.open.flags = open_flags;
-       nd->intent.open.create_mode = create_mode;
+       nd->intent.open.create_mode = 0;
        err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd);
        if (IS_ERR(nd->intent.open.file)) {
                if (err == 0) {
@@ -1161,38 +1177,6 @@ static int __path_lookup_intent_open(int dfd, const char *name,
        return err;
 }
 
-/**
- * path_lookup_open - lookup a file path with open intent
- * @dfd: the directory to use as base, or AT_FDCWD
- * @name: pointer to file name
- * @lookup_flags: lookup intent flags
- * @nd: pointer to nameidata
- * @open_flags: open intent flags
- */
-int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags,
-               struct nameidata *nd, int open_flags)
-{
-       return __path_lookup_intent_open(dfd, name, lookup_flags, nd,
-                       open_flags, 0);
-}
-
-/**
- * path_lookup_create - lookup a file path with open + create intent
- * @dfd: the directory to use as base, or AT_FDCWD
- * @name: pointer to file name
- * @lookup_flags: lookup intent flags
- * @nd: pointer to nameidata
- * @open_flags: open intent flags
- * @create_mode: create intent flags
- */
-static int path_lookup_create(int dfd, const char *name,
-                             unsigned int lookup_flags, struct nameidata *nd,
-                             int open_flags, int create_mode)
-{
-       return __path_lookup_intent_open(dfd, name, lookup_flags|LOOKUP_CREATE,
-                       nd, open_flags, create_mode);
-}
-
 static struct dentry *__lookup_hash(struct qstr *name,
                struct dentry *base, struct nameidata *nd)
 {
@@ -1470,20 +1454,18 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
 
        mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
 
-       for (p = p1; p->d_parent != p; p = p->d_parent) {
-               if (p->d_parent == p2) {
-                       mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
-                       mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
-                       return p;
-               }
+       p = d_ancestor(p2, p1);
+       if (p) {
+               mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
+               mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
+               return p;
        }
 
-       for (p = p2; p->d_parent != p; p = p->d_parent) {
-               if (p->d_parent == p1) {
-                       mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
-                       mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
-                       return p;
-               }
+       p = d_ancestor(p1, p2);
+       if (p) {
+               mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
+               mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
+               return p;
        }
 
        mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
@@ -1702,8 +1684,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
        /*
         * Create - we need to know the parent.
         */
-       error = path_lookup_create(dfd, pathname, LOOKUP_PARENT,
-                                  &nd, flag, mode);
+       error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
        if (error)
                return ERR_PTR(error);
 
@@ -1714,10 +1695,20 @@ struct file *do_filp_open(int dfd, const char *pathname,
         */
        error = -EISDIR;
        if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len])
-               goto exit;
+               goto exit_parent;
 
+       error = -ENFILE;
+       filp = get_empty_filp();
+       if (filp == NULL)
+               goto exit_parent;
+       nd.intent.open.file = filp;
+       nd.intent.open.flags = flag;
+       nd.intent.open.create_mode = mode;
        dir = nd.path.dentry;
        nd.flags &= ~LOOKUP_PARENT;
+       nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN;
+       if (flag & O_EXCL)
+               nd.flags |= LOOKUP_EXCL;
        mutex_lock(&dir->d_inode->i_mutex);
        path.dentry = lookup_hash(&nd);
        path.mnt = nd.path.mnt;
@@ -1822,6 +1813,7 @@ exit_dput:
 exit:
        if (!IS_ERR(nd.intent.open.file))
                release_open_intent(&nd);
+exit_parent:
        path_put(&nd.path);
        return ERR_PTR(error);
 
@@ -1914,7 +1906,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
        if (nd->last_type != LAST_NORM)
                goto fail;
        nd->flags &= ~LOOKUP_PARENT;
-       nd->flags |= LOOKUP_CREATE;
+       nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
        nd->intent.open.flags = O_EXCL;
 
        /*
@@ -2178,16 +2170,19 @@ static long do_rmdir(int dfd, const char __user *pathname)
                return error;
 
        switch(nd.last_type) {
-               case LAST_DOTDOT:
-                       error = -ENOTEMPTY;
-                       goto exit1;
-               case LAST_DOT:
-                       error = -EINVAL;
-                       goto exit1;
-               case LAST_ROOT:
-                       error = -EBUSY;
-                       goto exit1;
+       case LAST_DOTDOT:
+               error = -ENOTEMPTY;
+               goto exit1;
+       case LAST_DOT:
+               error = -EINVAL;
+               goto exit1;
+       case LAST_ROOT:
+               error = -EBUSY;
+               goto exit1;
        }
+
+       nd.flags &= ~LOOKUP_PARENT;
+
        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
        dentry = lookup_hash(&nd);
        error = PTR_ERR(dentry);
@@ -2265,6 +2260,9 @@ static long do_unlinkat(int dfd, const char __user *pathname)
        error = -EISDIR;
        if (nd.last_type != LAST_NORM)
                goto exit1;
+
+       nd.flags &= ~LOOKUP_PARENT;
+
        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
        dentry = lookup_hash(&nd);
        error = PTR_ERR(dentry);
@@ -2654,6 +2652,10 @@ asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
        if (newnd.last_type != LAST_NORM)
                goto exit2;
 
+       oldnd.flags &= ~LOOKUP_PARENT;
+       newnd.flags &= ~LOOKUP_PARENT;
+       newnd.flags |= LOOKUP_RENAME_TARGET;
+
        trap = lock_rename(new_dir, old_dir);
 
        old_dentry = lookup_hash(&oldnd);
@@ -2855,6 +2857,7 @@ EXPORT_SYMBOL(__page_symlink);
 EXPORT_SYMBOL(page_symlink);
 EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(kern_path);
 EXPORT_SYMBOL(vfs_path_lookup);
 EXPORT_SYMBOL(inode_permission);
 EXPORT_SYMBOL(vfs_permission);