vmscan: fix shrinker callback bug in fs/super.c

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

diff --git a/fs/namei.c b/fs/namei.c
index b52bc685465f5ecf1257d7982887b1435a7a6c2d..3d150720c37182ae188eb0a3ed7bb39de76cf823 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -137,7 +137,7 @@ static int do_getname(const char __user *filename, char *page)
        return retval;
 }
 
-static char *getname_flags(const char __user * filename, int flags)
+static char *getname_flags(const char __user *filename, int flags, int *empty)
 {
        char *tmp, *result;
 
@@ -148,6 +148,8 @@ static char *getname_flags(const char __user * filename, int flags)
 
                result = tmp;
                if (retval < 0) {
+                       if (retval == -ENOENT && empty)
+                               *empty = 1;
                        if (retval != -ENOENT || !(flags & LOOKUP_EMPTY)) {
                                __putname(tmp);
                                result = ERR_PTR(retval);
@@ -160,7 +162,7 @@ static char *getname_flags(const char __user * filename, int flags)
 
 char *getname(const char __user * filename)
 {
-       return getname_flags(filename, 0);
+       return getname_flags(filename, 0, 0);
 }
 
 #ifdef CONFIG_AUDITSYSCALL
@@ -721,12 +723,6 @@ static int follow_automount(struct path *path, unsigned flags,
        if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
                return -EREMOTE;
 
-       /* We don't want to mount if someone supplied AT_NO_AUTOMOUNT
-        * and this is the terminal part of the path.
-        */
-       if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_PARENT))
-               return -EISDIR; /* we actually want to stop here */
-
        /* We don't want to mount if someone's just doing a stat -
         * unless they're stat'ing a directory and appended a '/' to
         * the name.
@@ -739,7 +735,7 @@ static int follow_automount(struct path *path, unsigned flags,
         * of the daemon to instantiate them before they can be used.
         */
        if (!(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
-                    LOOKUP_OPEN | LOOKUP_CREATE)) &&
+                    LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) &&
            path->dentry->d_inode)
                return -EISDIR;
 
@@ -856,7 +852,7 @@ static int follow_managed(struct path *path, unsigned flags)
                mntput(path->mnt);
        if (ret == -EISDIR)
                ret = 0;
-       return ret;
+       return ret < 0 ? ret : need_mntput;
 }
 
 int follow_down_one(struct path *path)
@@ -904,6 +900,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
                        break;
                path->mnt = mounted;
                path->dentry = mounted->mnt_root;
+               nd->flags |= LOOKUP_JUMPED;
                nd->seq = read_seqcount_begin(&path->dentry->d_seq);
                /*
                 * Update the inode too. We don't need to re-check the
@@ -1217,6 +1214,8 @@ retry:
                path_put_conditional(path, nd);
                return err;
        }
+       if (err)
+               nd->flags |= LOOKUP_JUMPED;
        *inode = path->dentry->d_inode;
        return 0;
 }
@@ -1804,11 +1803,11 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
        return __lookup_hash(&this, base, NULL);
 }
 
-int user_path_at(int dfd, const char __user *name, unsigned flags,
-                struct path *path)
+int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
+                struct path *path, int *empty)
 {
        struct nameidata nd;
-       char *tmp = getname_flags(name, flags);
+       char *tmp = getname_flags(name, flags, empty);
        int err = PTR_ERR(tmp);
        if (!IS_ERR(tmp)) {
 
@@ -1822,6 +1821,12 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
        return err;
 }
 
+int user_path_at(int dfd, const char __user *name, unsigned flags,
+                struct path *path)
+{
+       return user_path_at_empty(dfd, name, flags, path, 0);
+}
+
 static int user_path_parent(int dfd, const char __user *path,
                        struct nameidata *nd, char **name)
 {
@@ -2147,6 +2152,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
        }
 
        /* create side of things */
+       /*
+        * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been
+        * cleared when we got to the last component we are about to look up
+        */
        error = complete_walk(nd);
        if (error)
                return ERR_PTR(error);
@@ -2215,6 +2224,9 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
        if (error < 0)
                goto exit_dput;
 
+       if (error)
+               nd->flags |= LOOKUP_JUMPED;
+
        error = -ENOENT;
        if (!path->dentry->d_inode)
                goto exit_dput;
@@ -2224,6 +2236,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
        path_to_nameidata(path, nd);
        nd->inode = path->dentry->d_inode;
+       /* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
+       error = complete_walk(nd);
+       if (error)
+               goto exit;
        error = -EISDIR;
        if (S_ISDIR(nd->inode->i_mode))
                goto exit;
@@ -2616,6 +2632,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
        if (!dir->i_op->rmdir)
                return -EPERM;
 
+       dget(dentry);
        mutex_lock(&dentry->d_inode->i_mutex);
 
        error = -EBUSY;
@@ -2636,6 +2653,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
 
 out:
        mutex_unlock(&dentry->d_inode->i_mutex);
+       dput(dentry);
        if (!error)
                d_delete(dentry);
        return error;
@@ -3025,6 +3043,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
        if (error)
                return error;
 
+       dget(new_dentry);
        if (target)
                mutex_lock(&target->i_mutex);
 
@@ -3045,6 +3064,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
 out:
        if (target)
                mutex_unlock(&target->i_mutex);
+       dput(new_dentry);
        if (!error)
                if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
                        d_move(old_dentry,new_dentry);