The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 51d31149a88b5c5a8d2d33f06df93f6187a25b4c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024030406-ambiguity-strict-2ed2@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

51d31149a88b ("ceph: switch to corrected encoding of max_xattr_size in mdsmap")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 51d31149a88b5c5a8d2d33f06df93f6187a25b4c Mon Sep 17 00:00:00 2001 From: Xiubo Li xiubli@redhat.com Date: Mon, 19 Feb 2024 13:14:32 +0800 Subject: [PATCH] ceph: switch to corrected encoding of max_xattr_size in mdsmap

The addition of bal_rank_mask with encoding version 17 was merged into ceph.git in Oct 2022 and made it into v18.2.0 release normally. A few months later, the much delayed addition of max_xattr_size got merged, also with encoding version 17, placed before bal_rank_mask in the encoding -- but it didn't make v18.2.0 release.

The way this ended up being resolved on the MDS side is that bal_rank_mask will continue to be encoded in version 17 while max_xattr_size is now encoded in version 18. This does mean that older kernels will misdecode version 17, but this is also true for v18.2.0 and v18.2.1 clients in userspace.

The best we can do is backport this adjustment -- see ceph.git commit 78abfeaff27fee343fb664db633de5b221699a73 for details.

[ idryomov: changelog ]

Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/64440 Fixes: d93231a6bc8a ("ceph: prevent a client from exceeding the MDS maximum xattr size") Signed-off-by: Xiubo Li xiubli@redhat.com Reviewed-by: Patrick Donnelly pdonnell@ibm.com Reviewed-by: Venky Shankar vshankar@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com

diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c index fae97c25ce58..8109aba66e02 100644 --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -380,10 +380,11 @@ struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p, ceph_decode_skip_8(p, end, bad_ext); /* required_client_features */ ceph_decode_skip_set(p, end, 64, bad_ext); + /* bal_rank_mask */ + ceph_decode_skip_string(p, end, bad_ext); + } + if (mdsmap_ev >= 18) { ceph_decode_64_safe(p, end, m->m_max_xattr_size, bad_ext); - } else { - /* This forces the usage of the (sync) SETXATTR Op */ - m->m_max_xattr_size = 0; } bad_ext: doutc(cl, "m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n", diff --git a/fs/ceph/mdsmap.h b/fs/ceph/mdsmap.h index 89f1931f1ba6..1f2171dd01bf 100644 --- a/fs/ceph/mdsmap.h +++ b/fs/ceph/mdsmap.h @@ -27,7 +27,11 @@ struct ceph_mdsmap { u32 m_session_timeout; /* seconds */ u32 m_session_autoclose; /* seconds */ u64 m_max_file_size; - u64 m_max_xattr_size; /* maximum size for xattrs blob */ + /* + * maximum size for xattrs blob. + * Zeroed by default to force the usage of the (sync) SETXATTR Op. + */ + u64 m_max_xattr_size; u32 m_max_mds; /* expected up:active mds number */ u32 m_num_active_mds; /* actual up:active mds number */ u32 possible_max_rank; /* possible max rank index */