[PATCH] r/o bind mounts: get callers of vfs_mknod/create/mkdir()

This takes care of all of the direct callers of vfs_mknod().
Since a few of these cases also handle normal file creation
as well, this also covers some calls to vfs_create().

So that we don't have to make three mnt_want/drop_write()
calls inside of the switch statement, we move some of its
logic outside of the switch and into a helper function
suggested by Christoph.

This also encapsulates a fix for mknod(S_IFREG) that Miklos
found.

[AV: merged mkdir handling, added missing nfsd pieces]

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 4e77a1a3bd73..145b3c877a27 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -155,7 +155,11 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
                 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
                 goto out_put;
         }
+        status = mnt_want_write(rec_dir.path.mnt);
+        if (status)
+                goto out_put;
         status = vfs_mkdir(rec_dir.path.dentry->d_inode, dentry, S_IRWXU);
+        mnt_drop_write(rec_dir.path.mnt);
 out_put:
         dput(dentry);
 out_unlock: