diff options
| author | Luís Henriques <lhenriques@suse.de> | 2022-06-03 14:29:09 +0100 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2022-08-03 00:54:12 +0200 |
| commit | d93231a6bc8a452323d5fef16cca7107ce483a27 (patch) | |
| tree | 439f6d9295ccfee1165b0c5c9d9d8de01b65a724 /fs/ceph/xattr.c | |
| parent | 8266c4d7a7469c3fd45ee2b4ebc01aac311c6c48 (diff) | |
ceph: prevent a client from exceeding the MDS maximum xattr size
The MDS tries to enforce a limit on the total key/values in extended
attributes. However, this limit is enforced only if doing a synchronous
operation (MDS_OP_SETXATTR) -- if we're buffering the xattrs, the MDS
doesn't have a chance to enforce these limits.
This patch adds support for decoding the xattrs maximum size setting that is
distributed in the mdsmap. Then, when setting an xattr, the kernel client
will revert to do a synchronous operation if that maximum size is exceeded.
While there, fix a dout() that would trigger a printk warning:
[ 98.718078] ------------[ cut here ]------------
[ 98.719012] precision 65536 too large
[ 98.719039] WARNING: CPU: 1 PID: 3755 at lib/vsprintf.c:2703 vsnprintf+0x5e3/0x600
...
Link: https://tracker.ceph.com/issues/55725
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/xattr.c')
| -rw-r--r-- | fs/ceph/xattr.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index f141f5246163..f31350cda960 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -1086,7 +1086,7 @@ static int ceph_sync_setxattr(struct inode *inode, const char *name, flags |= CEPH_XATTR_REMOVE; } - dout("setxattr value=%.*s\n", (int)size, value); + dout("setxattr value size: %zu\n", size); /* do request */ req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS); @@ -1184,8 +1184,14 @@ int __ceph_setxattr(struct inode *inode, const char *name, spin_lock(&ci->i_ceph_lock); retry: issued = __ceph_caps_issued(ci, NULL); - if (ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL)) + required_blob_size = __get_required_blob_size(ci, name_len, val_len); + if ((ci->i_xattrs.version == 0) || !(issued & CEPH_CAP_XATTR_EXCL) || + (required_blob_size > mdsc->mdsmap->m_max_xattr_size)) { + dout("%s do sync setxattr: version: %llu size: %d max: %llu\n", + __func__, ci->i_xattrs.version, required_blob_size, + mdsc->mdsmap->m_max_xattr_size); goto do_sync; + } if (!lock_snap_rwsem && !ci->i_head_snapc) { lock_snap_rwsem = true; @@ -1201,8 +1207,6 @@ retry: ceph_cap_string(issued)); __build_xattrs(inode); - required_blob_size = __get_required_blob_size(ci, name_len, val_len); - if (!ci->i_xattrs.prealloc_blob || required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) { struct ceph_buffer *blob; |