Luís Henriques <lhenriques@xxxxxxx> writes: > 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 forces the usage of the synchronous operation if xattrs size hits > the maximum size that is set on the MDS by default (64k). > > 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 > ... > > URL: https://tracker.ceph.com/issues/55725 > Signed-off-by: Luís Henriques <lhenriques@xxxxxxx> > --- > fs/ceph/xattr.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c > index afec84088471..09751a5f028c 100644 > --- a/fs/ceph/xattr.c > +++ b/fs/ceph/xattr.c > @@ -15,6 +15,12 @@ > #define XATTR_CEPH_PREFIX "ceph." > #define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1) > > +/* > + * Maximum size of xattrs the MDS can handle per inode by default. This > + * includes the attribute name and 4+4 bytes for the key/value sizes. > + */ > +#define MDS_MAX_XATTR_PAIRS_SIZE (1<<16) /* 64K */ > + > static int __remove_xattr(struct ceph_inode_info *ci, > struct ceph_inode_xattr *xattr); > > @@ -1078,7 +1084,7 @@ 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: ld\n", size); Oops! Looks like someone ate a '%' char. Oh well, I won't bother sending out a new version for now as this is an RFC and the MDS side is what really needs fixing. In fact, the client-side may be something very different from this RFC. Cheers, -- Luís > > /* do request */ > req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS); > @@ -1176,8 +1182,13 @@ 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 >= MDS_MAX_XATTR_PAIRS_SIZE)) { > + dout("%s do sync setxattr: version: %llu blob size: %d\n", > + __func__, ci->i_xattrs.version, required_blob_size); > goto do_sync; > + } > > if (!lock_snap_rwsem && !ci->i_head_snapc) { > lock_snap_rwsem = true; > @@ -1193,8 +1204,6 @@ int __ceph_setxattr(struct inode *inode, const char *name, > 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;
