The patch titled
r/o bind mounts: elevate write count over calls to vfs_rename()
has been removed from the -mm tree. Its filename is
ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch
This patch was dropped because Viro's comments sounded rather serious
------------------------------------------------------
Subject: r/o bind mounts: elevate write count over calls to vfs_rename()
From: Dave Hansen <haveblue@xxxxxxxxxx>
This does create a little helper in the NFS code to make an if() a little bit
less ugly.
Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>
Cc: Serge Hallyn <serue@xxxxxxxxxx>
Cc: Herbert Poetzl <herbert@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/namei.c | 4 ++++
fs/nfsd/vfs.c | 25 ++++++++++++++++++++-----
2 files changed, 24 insertions(+), 5 deletions(-)
diff -puN fs/namei.c~ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename fs/namei.c
--- a/fs/namei.c~ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename
+++ a/fs/namei.c
@@ -2544,8 +2544,12 @@ static int do_rename(int olddfd, const c
if (new_dentry == trap)
goto exit5;
+ error = mnt_want_write(oldnd.mnt);
+ if (error)
+ goto exit5;
error = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry);
+ mnt_drop_write(oldnd.mnt);
exit5:
dput(new_dentry);
exit4:
diff -puN fs/nfsd/vfs.c~ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename fs/nfsd/vfs.c
--- a/fs/nfsd/vfs.c~ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename
+++ a/fs/nfsd/vfs.c
@@ -1534,6 +1534,14 @@ out_nfserr:
goto out_unlock;
}
+static inline int svc_msnfs(struct svc_fh *ffhp)
+{
+#ifdef MSNFS
+ return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
+#else
+ return 0;
+#endif
+}
/*
* Rename a file
* N.B. After this call _both_ ffhp and tfhp need an fh_put
@@ -1594,20 +1602,27 @@ nfsd_rename(struct svc_rqst *rqstp, stru
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))) {
err = -EPERM;
- } else
-#endif
+ goto out_dput_new;
+ }
+
+ err = -EXDEV;
+ if (ffhp->fh_export->ex_mnt != tfhp->fh_export->ex_mnt)
+ goto out_dput_new;
+ err = mnt_want_write(ffhp->fh_export->ex_mnt);
+ if (err)
+ goto out_dput_new;
+
err = vfs_rename(fdir, odentry, tdir, ndentry);
if (!err && EX_ISSYNC(tfhp->fh_export)) {
err = nfsd_sync_dir(tdentry);
if (!err)
err = nfsd_sync_dir(fdentry);
}
-
+ mnt_drop_write(ffhp->fh_export->ex_mnt);
out_dput_new:
dput(ndentry);
out_dput_old:
_
Patches currently in -mm which might be from haveblue@xxxxxxxxxx are
origin.patch
git-acpi.patch
ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch
ro-bind-mounts-tricky-elevate-write-count-files-are-opened.patch
ro-bind-mounts-elevate-writer-count-for-do_sys_truncate.patch
ro-bind-mounts-elevate-write-count-for-do_utimes.patch
ro-bind-mounts-elevate-write-count-for-do_sys_utime-and-touch_atime.patch
ro-bind-mounts-sys_mknodat-elevate-write-count-for-vfs_mknod-create.patch
ro-bind-mounts-elevate-mnt-writers-for-vfs_unlink-callers.patch
ro-bind-mounts-do_rmdir-elevate-write-count.patch
ro-bind-mounts-elevate-writer-count-for-custom-struct-file.patch
ro-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
page-owner-tracking-leak-detector.patch
x86-e820-debugging.patch
-
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