From 4ac4c23eaa389859f746a6ef31e1c71d880312f4 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 11 Jan 2021 12:35:48 -0500 Subject: ceph: decode alternate_name in lease info MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Ceph is a bit different from local filesystems, in that we don't want to store filenames as raw binary data, since we may also be dealing with clients that don't support fscrypt. We could just base64-encode the encrypted filenames, but that could leave us with filenames longer than NAME_MAX. It turns out that the MDS doesn't care much about filename length, but the clients do. To manage this, we've added a new "alternate name" field that can be optionally added to any dentry that we'll use to store the binary crypttext of the filename if its base64-encoded value will be longer than NAME_MAX. When a dentry has one of these names attached, the MDS will send it along in the lease info, which we can then store for later usage. Signed-off-by: Jeff Layton Reviewed-by: Xiubo Li Reviewed-and-tested-by: Luís Henriques Reviewed-by: Milind Changire Signed-off-by: Ilya Dryomov --- fs/ceph/mds_client.c | 43 +++++++++++++++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 10 deletions(-) (limited to 'fs/ceph/mds_client.c') diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 126529ec7ca9..34b8c0273427 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -310,27 +310,47 @@ bad: static int parse_reply_info_lease(void **p, void *end, struct ceph_mds_reply_lease **lease, - u64 features) + u64 features, u32 *altname_len, u8 **altname) { + u8 struct_v; + u32 struct_len; + void *lend; + if (features == (u64)-1) { - u8 struct_v, struct_compat; - u32 struct_len; + u8 struct_compat; + ceph_decode_8_safe(p, end, struct_v, bad); ceph_decode_8_safe(p, end, struct_compat, bad); + /* struct_v is expected to be >= 1. we only understand * encoding whose struct_compat == 1. */ if (!struct_v || struct_compat != 1) goto bad; + ceph_decode_32_safe(p, end, struct_len, bad); - ceph_decode_need(p, end, struct_len, bad); - end = *p + struct_len; + } else { + struct_len = sizeof(**lease); + *altname_len = 0; + *altname = NULL; } - ceph_decode_need(p, end, sizeof(**lease), bad); + lend = *p + struct_len; + ceph_decode_need(p, end, struct_len, bad); *lease = *p; *p += sizeof(**lease); - if (features == (u64)-1) - *p = end; + + if (features == (u64)-1) { + if (struct_v >= 2) { + ceph_decode_32_safe(p, end, *altname_len, bad); + ceph_decode_need(p, end, *altname_len, bad); + *altname = *p; + *p += *altname_len; + } else { + *altname = NULL; + *altname_len = 0; + } + } + *p = lend; return 0; bad: return -EIO; @@ -360,7 +380,8 @@ static int parse_reply_info_trace(void **p, void *end, info->dname = *p; *p += info->dname_len; - err = parse_reply_info_lease(p, end, &info->dlease, features); + err = parse_reply_info_lease(p, end, &info->dlease, features, + &info->altname_len, &info->altname); if (err < 0) goto out_bad; } @@ -427,9 +448,11 @@ static int parse_reply_info_readdir(void **p, void *end, dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name); /* dentry lease */ - err = parse_reply_info_lease(p, end, &rde->lease, features); + err = parse_reply_info_lease(p, end, &rde->lease, features, + &rde->altname_len, &rde->altname); if (err) goto out_bad; + /* inode */ err = parse_reply_info_in(p, end, &rde->inode, features); if (err < 0) -- cgit v1.2.3