From 9079b1eb1753f217c3de9f1b7dd7fd549cc3f0cf Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 15 Feb 2008 14:37:49 -0800 Subject: [PATCH] [PATCH] r/o bind mounts: get write access for vfs_rename() callers This also uses the little helper in the NFS code to make an if() a little bit less ugly. We introduced the helper at the beginning of the series. Acked-by: Al Viro Signed-off-by: Christoph Hellwig Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- fs/namei.c | 4 ++++ fs/nfsd/vfs.c | 17 +++++++++++++---- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 00df735fb50..83c843b3fea 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2718,8 +2718,12 @@ static int do_rename(int olddfd, const char *oldname, if (new_dentry == trap) goto exit5; + error = mnt_want_write(oldnd.path.mnt); + if (error) + goto exit5; error = vfs_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, new_dentry); + mnt_drop_write(oldnd.path.mnt); exit5: dput(new_dentry); exit4: diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 71f89948230..18a4cc9feeb 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1710,13 +1710,20 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, if (ndentry == trap) goto out_dput_new; -#ifdef MSNFS - if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && + if (svc_msnfs(ffhp) && ((atomic_read(&odentry->d_count) > 1) || (atomic_read(&ndentry->d_count) > 1))) { host_err = -EPERM; - } else -#endif + goto out_dput_new; + } + + host_err = -EXDEV; + if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) + goto out_dput_new; + host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); + if (host_err) + goto out_dput_new; + host_err = vfs_rename(fdir, odentry, tdir, ndentry); if (!host_err && EX_ISSYNC(tfhp->fh_export)) { host_err = nfsd_sync_dir(tdentry); @@ -1724,6 +1731,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, host_err = nfsd_sync_dir(fdentry); } + mnt_drop_write(ffhp->fh_export->ex_path.mnt); + out_dput_new: dput(ndentry); out_dput_old: -- 2.41.0