The patch titled
r/o bind mounts: honor r/w changes at do_remount() time
has been added to the -mm tree. Its filename is
r-o-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: r/o bind mounts: honor r/w changes at do_remount() time
From: Dave Hansen <[EMAIL PROTECTED]>
Originally from: Herbert Poetzl <[EMAIL PROTECTED]>
This is the core of the read-only bind mount patch set.
Note that this does _not_ add a "ro" option directly to the bind mount
operation. If you require such a mount, you must first do the bind, then
follow it up with a 'mount -o remount,ro' operation.
Signed-off-by: Dave Hansen <[EMAIL PROTECTED]>
Cc: Miklos Szeredi <[EMAIL PROTECTED]>
Cc: Ram Pai <[EMAIL PROTECTED]>
Cc: Al Viro <[EMAIL PROTECTED]>
Cc: Christoph Hellwig <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
fs/namespace.c | 24 ++++++++++++++++++++++--
fs/open.c | 2 +-
2 files changed, 23 insertions(+), 3 deletions(-)
diff -puN fs/namespace.c~r-o-bind-mounts-honor-r-w-changes-at-do_remount-time
fs/namespace.c
--- a/fs/namespace.c~r-o-bind-mounts-honor-r-w-changes-at-do_remount-time
+++ a/fs/namespace.c
@@ -428,7 +428,7 @@ static int show_vfsmnt(struct seq_file *
seq_path(m, mnt, mnt->mnt_root, " \t\n\\");
seq_putc(m, ' ');
mangle(m, mnt->mnt_sb->s_type->name);
- seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? " ro" : " rw");
+ seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
if (mnt->mnt_sb->s_flags & fs_infop->flag)
seq_puts(m, fs_infop->str);
@@ -997,6 +997,23 @@ out:
return err;
}
+static int change_mount_flags(struct vfsmount *mnt, int ms_flags)
+{
+ int error = 0;
+ int readonly_request = 0;
+
+ if (ms_flags & MS_RDONLY)
+ readonly_request = 1;
+ if (readonly_request == __mnt_is_readonly(mnt))
+ return 0;
+
+ if (readonly_request)
+ error = mnt_make_readonly(mnt);
+ else
+ __mnt_unmake_readonly(mnt);
+ return error;
+}
+
/*
* change filesystem flags. dir should be a physical root of filesystem.
* If you've mounted a non-root directory somewhere and want to do remount
@@ -1018,7 +1035,10 @@ static int do_remount(struct nameidata *
return -EINVAL;
down_write(&sb->s_umount);
- err = do_remount_sb(sb, flags, data, 0);
+ if (flags & MS_BIND)
+ err = change_mount_flags(nd->mnt, flags);
+ else
+ err = do_remount_sb(sb, flags, data, 0);
if (!err)
nd->mnt->mnt_flags = mnt_flags;
up_write(&sb->s_umount);
diff -puN fs/open.c~r-o-bind-mounts-honor-r-w-changes-at-do_remount-time
fs/open.c
--- a/fs/open.c~r-o-bind-mounts-honor-r-w-changes-at-do_remount-time
+++ a/fs/open.c
@@ -401,7 +401,7 @@ asmlinkage long sys_faccessat(int dfd, c
special_file(nd.dentry->d_inode->i_mode))
goto out_path_release;
- if(IS_RDONLY(nd.dentry->d_inode))
+ if(__mnt_is_readonly(nd.mnt) || IS_RDONLY(nd.dentry->d_inode))
res = -EROFS;
out_path_release:
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
r-o-bind-mounts-filesystem-helpers-for-custom-struct-files.patch
r-o-bind-mounts-add-vfsmount-writer-counts.patch
r-o-bind-mounts-record-when-sb_writer_count-elevated-for-inode.patch
r-o-bind-mounts-elevate-writer-count-for-chown-and-friends.patch
r-o-bind-mounts-elevate-mnt-writers-for-callers-of-vfs_mkdir.patch
r-o-bind-mounts-elevate-write-count-during-entire-ncp_ioctl.patch
r-o-bind-mounts-elevate-write-count-for-link-and-symlink-calls.patch
r-o-bind-mounts-elevate-mount-count-for-extended-attributes.patch
r-o-bind-mounts-mount_is_safe-add-comment.patch
r-o-bind-mounts-unix_find_other-elevate-write-count-for-touch_atime.patch
r-o-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch
r-o-bind-mounts-elevate-write-count-files-are-opened.patch
r-o-bind-mounts-elevate-writer-count-for-do_sys_truncate.patch
r-o-bind-mounts-elevate-write-count-for-do_utimes.patch
r-o-bind-mounts-elevate-write-count-for-do_sys_utime-and-touch_atime.patch
r-o-bind-mounts-sys_mknodat-elevate-write-count-for-vfs_mknod-create.patch
r-o-bind-mounts-elevate-mnt-writers-for-vfs_unlink-callers.patch
r-o-bind-mounts-do_rmdir-elevate-write-count.patch
r-o-bind-mounts-elevate-writer-count-for-custom-struct_file.patch
r-o-bind-mounts-gfs-check-nlink-count.patch
r-o-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
r-o-bind-mounts-kill-open-files-traverse-on-remount-ro.patch
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