[adding ceph-devel CC]
On Fri, 21 Oct 2011, Noah Watkins wrote:
> Hi Sage,
>
> This commit works fine, but I stumbled upon an additional complication
> when building up the rest of the ACL code.
>
> The ACL initialization semantics can alter the i_mode entry of the new
> inode. However, since i_mode is filled in from the MDS request reply it
> seems as though there is a potential conflict in semantics between what
> the MDS computes, and what the ACL code may want to compute (I suppose
> strict POSIX).
>
> The r_fmode field of ceph_mds_request seems to be informing the MDS of
> modes, but at least for ceph_mkdir, doesn't appear to be used at all.
> Should the r_fmode be fully computed by the clients?
The r_fmode is actually a client-side thing use for initializing the
struct file. (It's also not a unix permissions mode, but from the
CEPH_FILE_MODE_* namespace.)
The mode for the newly created object is being passed to the mds for each
request as part of the args struct/union. And it looks like it's being
used on the MDS for everything except symlink (which always gets 0777 +
the type bits). For example, for mkdir, it's
unsigned mode = req->head.args.mkdir.mode;
mode &= ~S_IFMT;
mode |= S_IFDIR;
and on the client there is
req->r_args.mkdir.mode = cpu_to_le32(mode);
in ceph_mkdir() in dir.c.
sage
>
> -Noah
>
> ----- Original Message -----
> From: "Sage Weil" <[email protected]>
> To: [email protected]
> Sent: Tuesday, October 18, 2011 1:50:08 PM
> Subject: [ceph-commit] [NewDreamNetwork/ceph] d2d214: mds: handle xattrs on
> inode creation (fwd)
>
> Just need to attach the new xattr(s) in the msg payload. This will be
> similar to what setxattr does with r_pages and r_num_pages, except the
> page content will be
>
> <u32> number of xattrs
> (
> <u32> xattr name length
> xattr name
> <u32> xattr value length
> xattr value
> ) * N
>
>
> ---------- Forwarded message ----------
> Date: Tue, 18 Oct 2011 13:39:13 -0700
> From: [email protected]
> To: [email protected]
> Subject: [ceph-commit] [NewDreamNetwork/ceph] d2d214: mds: handle xattrs on
> inode creation
>
> Branch: refs/heads/wip-create-xattr
> Home: https://github.com/NewDreamNetwork/ceph
>
> Commit: d2d2149d364ee5b5fe078a964e2c1089c2153cd1
>
> https://github.com/NewDreamNetwork/ceph/commit/d2d2149d364ee5b5fe078a964e2c1089c2153cd1
> Author: Sage Weil <[email protected]>
> Date: 2011-10-18 (Tue, 18 Oct 2011)
>
> Changed paths:
> M src/mds/Server.cc
>
> Log Message:
> -----------
> mds: handle xattrs on inode creation
>
> Allow mknod, mkdir, symlink, create to provide xattrs for the new
> inode. This will be used by the kclient to set ACLs on new inodes
> based on the parent directory.
>
> Signed-off-by: Sage Weil <[email protected]>
>
>
> _______________________________________________
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>
>
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