[PATCH] r/o bind mounts: write counts for link/symlink

[AV: add missing nfsd pieces]

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 3fbcf2021a2e..00df735fb509 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2387,7 +2387,12 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
         if (IS_ERR(dentry))
                 goto out_unlock;
 
+        error = mnt_want_write(nd.path.mnt);
+        if (error)
+                goto out_dput;
         error = vfs_symlink(nd.path.dentry->d_inode, dentry, from, S_IALLUGO);
+        mnt_drop_write(nd.path.mnt);
+out_dput:
         dput(dentry);
 out_unlock:
         mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
@@ -2482,7 +2487,12 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
         error = PTR_ERR(new_dentry);
         if (IS_ERR(new_dentry))
                 goto out_unlock;
+        error = mnt_want_write(nd.path.mnt);
+        if (error)
+                goto out_dput;
         error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry);
+        mnt_drop_write(nd.path.mnt);
+out_dput:
         dput(new_dentry);
 out_unlock:
         mutex_unlock(&nd.path.dentry->d_inode->i_mutex);