On Tue, Jan 11, 2022 at 7:18 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > On Tue, 2022-01-11 at 18:53 +0530, Milind Changire wrote: > > responses below ... > > > > On Tue, Jan 11, 2022 at 6:19 PM Jeff Layton <jlayton@xxxxxxxxxx> > > wrote: > > > On Tue, 2022-01-11 at 17:54 +0530, Milind Changire wrote: > > > > Problem: > > > > Directory vxattrs like ceph.dir.pin* and ceph.dir.layout* may not > > > > be > > > > propagated to the client as frequently to keep them updated. This > > > > creates vxattr availability problems. > > > > > > > > Solution: > > > > Adds new getvxattr op to fetch ceph.dir.pin*, ceph.dir.layout* and > > > > ceph.file.layout* vxattrs. > > > > If the entire layout for a dir or a file is being set, then it is > > > > expected that the layout be set in standard JSON format. > > > > Individual > > > > field value retrieval is not wrapped in JSON. The JSON format also > > > > applies while setting the vxattr if the entire layout is being set > > > > in > > > > one go. > > > > As a temporary measure, setting a vxattr can also be done in the > > > > old > > > > format. The old format will be deprecated in the future. > > > > > > > > URL: https://tracker.ceph.com/issues/51062 > > > > Signed-off-by: Milind Changire <mchangir@xxxxxxxxxx> > > > > --- > > > > fs/ceph/inode.c | 51 ++++++++++++++++++++++++++++ > > > > fs/ceph/mds_client.c | 27 ++++++++++++++- > > > > fs/ceph/mds_client.h | 12 ++++++- > > > > fs/ceph/strings.c | 1 + > > > > fs/ceph/super.h | 1 + > > > > fs/ceph/xattr.c | 65 > > > > ++++++++++++++++++++++++++++++++++++ > > > > include/linux/ceph/ceph_fs.h | 1 + > > > > 7 files changed, 156 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > > > > index e3322fcb2e8d..f29d59b63c52 100644 > > > > --- a/fs/ceph/inode.c > > > > +++ b/fs/ceph/inode.c > > > > @@ -2291,6 +2291,57 @@ int __ceph_do_getattr(struct inode *inode, > > > > struct page *locked_page, > > > > return err; > > > > } > > > > > > > > +int ceph_do_getvxattr(struct inode *inode, const char *name, void > > > > *value, > > > > + size_t size) > > > > +{ > > > > + struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb); > > > > + struct ceph_mds_client *mdsc = fsc->mdsc; > > > > + struct ceph_mds_request *req; > > > > + int mode = USE_AUTH_MDS; > > > > + int err; > > > > + char *xattr_value; > > > > + size_t xattr_value_len; > > > > + > > > > + req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETVXATTR, > > > > mode); > > > > + if (IS_ERR(req)) { > > > > + err = -ENOMEM; > > > > + goto out; > > > > + } > > > > + > > > > + req->r_path2 = kstrdup(name, GFP_NOFS); > > > > + if (!req->r_path2) { > > > > + err = -ENOMEM; > > > > + goto put; > > > > + } > > > > + > > > > + ihold(inode); > > > > + req->r_inode = inode; > > > > + err = ceph_mdsc_do_request(mdsc, NULL, req); > > > > + if (err < 0) > > > > + goto put; > > > > + > > > > + xattr_value = req->r_reply_info.xattr_info.xattr_value; > > > > + xattr_value_len = req- > > > > >r_reply_info.xattr_info.xattr_value_len; > > > > + > > > > + dout("do_getvxattr xattr_value_len:%lu, size:%lu\n", > > > > xattr_value_len, size); > > > > + > > > > + err = xattr_value_len; > > > > + if (size == 0) > > > > + goto put; > > > > + > > > > + if (xattr_value_len > size) { > > > > + err = -ERANGE; > > > > + goto put; > > > > + } > > > > + > > > > + memcpy(value, xattr_value, xattr_value_len); > > > > +put: > > > > + ceph_mdsc_put_request(req); > > > > +out: > > > > + dout("do_getvxattr result=%d\n", err); > > > > + return err; > > > > +} > > > > + > > > > > > > > /* > > > > * Check inode permissions. We verify we have a valid value for > > > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > > > > index c30eefc0ac19..a5eafc71d976 100644 > > > > --- a/fs/ceph/mds_client.c > > > > +++ b/fs/ceph/mds_client.c > > > > @@ -555,6 +555,29 @@ static int parse_reply_info_create(void **p, > > > > void *end, > > > > return -EIO; > > > > } > > > > > > > > +static int parse_reply_info_getvxattr(void **p, void *end, > > > > + struct > > > > ceph_mds_reply_info_parsed *info, > > > > + u64 features) > > > > +{ > > > > + u8 struct_v, struct_compat; > > > > + u32 struct_len; > > > > + u32 value_len; > > > > + > > > > + ceph_decode_8_safe(p, end, struct_v, bad); > > > > + ceph_decode_8_safe(p, end, struct_compat, bad); > > > > + ceph_decode_32_safe(p, end, struct_len, bad); > > > > + ceph_decode_32_safe(p, end, value_len, bad); > > > > + > > > > + if (value_len == end - *p) { > > > > + info->xattr_info.xattr_value = *p; > > > > + info->xattr_info.xattr_value_len = end - *p; > > > > + *p = end; > > > > + return info->xattr_info.xattr_value_len; > > > > + } > > > > > > The kernel uses tab indent almost exclusively. Can you fix the > > > indention > > > above (and anywhere else I missed)? > > > > > > > > > I'll fix this. newbie issues :P > > > > > > > > > +bad: > > > > + return -EIO; > > > > +} > > > > + > > > > /* > > > > * parse extra results > > > > */ > > > > @@ -570,6 +593,8 @@ static int parse_reply_info_extra(void **p, > > > > void *end, > > > > return parse_reply_info_readdir(p, end, info, > > > > features); > > > > else if (op == CEPH_MDS_OP_CREATE) > > > > return parse_reply_info_create(p, end, info, > > > > features, s); > > > > + else if (op == CEPH_MDS_OP_GETVXATTR) > > > > + return parse_reply_info_getvxattr(p, end, info, > > > > features); > > > > else > > > > return -EIO; > > > > } > > > > @@ -615,7 +640,7 @@ static int parse_reply_info(struct > > > > ceph_mds_session *s, struct ceph_msg *msg, > > > > > > > > if (p != end) > > > > goto bad; > > > > - return 0; > > > > + return err; > > > > > > > > bad: > > > > err = -EIO; > > > > diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h > > > > index 97c7f7bfa55f..f2a8e5af3c2e 100644 > > > > --- a/fs/ceph/mds_client.h > > > > +++ b/fs/ceph/mds_client.h > > > > @@ -29,8 +29,10 @@ enum ceph_feature_type { > > > > CEPHFS_FEATURE_MULTI_RECONNECT, > > > > CEPHFS_FEATURE_DELEG_INO, > > > > CEPHFS_FEATURE_METRIC_COLLECT, > > > > + CEPHFS_FEATURE_ALTERNATE_NAME, > > > > + CEPHFS_FEATURE_GETVXATTR, > > > > > > > > - CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_METRIC_COLLECT, > > > > + CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_GETVXATTR, > > > > }; > > > > > > > > /* > > > > @@ -45,6 +47,8 @@ enum ceph_feature_type { > > > > CEPHFS_FEATURE_MULTI_RECONNECT, \ > > > > CEPHFS_FEATURE_DELEG_INO, \ > > > > CEPHFS_FEATURE_METRIC_COLLECT, \ > > > > + CEPHFS_FEATURE_ALTERNATE_NAME, \ > > > > + CEPHFS_FEATURE_GETVXATTR, \ > > > > \ > > > > CEPHFS_FEATURE_MAX, \ > > > > } > > > > @@ -100,6 +104,11 @@ struct ceph_mds_reply_dir_entry { > > > > loff_t offset; > > > > }; > > > > > > > > +struct ceph_mds_reply_xattr { > > > > + char *xattr_value; > > > > + size_t xattr_value_len; > > > > +}; > > > > + > > > > /* > > > > * parsed info about an mds reply, including information about > > > > * either: 1) the target inode and/or its parent directory and > > > > dentry, > > > > @@ -115,6 +124,7 @@ struct ceph_mds_reply_info_parsed { > > > > char *dname; > > > > u32 dname_len; > > > > struct ceph_mds_reply_lease *dlease; > > > > + struct ceph_mds_reply_xattr xattr_info; > > > > > > > > /* extra */ > > > > union { > > > > diff --git a/fs/ceph/strings.c b/fs/ceph/strings.c > > > > index 573bb9556fb5..e36e8948e728 100644 > > > > --- a/fs/ceph/strings.c > > > > +++ b/fs/ceph/strings.c > > > > @@ -60,6 +60,7 @@ const char *ceph_mds_op_name(int op) > > > > case CEPH_MDS_OP_LOOKUPINO: return "lookupino"; > > > > case CEPH_MDS_OP_LOOKUPNAME: return "lookupname"; > > > > case CEPH_MDS_OP_GETATTR: return "getattr"; > > > > + case CEPH_MDS_OP_GETVXATTR: return "getvxattr"; > > > > case CEPH_MDS_OP_SETXATTR: return "setxattr"; > > > > case CEPH_MDS_OP_SETATTR: return "setattr"; > > > > case CEPH_MDS_OP_RMXATTR: return "rmxattr"; > > > > diff --git a/fs/ceph/super.h b/fs/ceph/super.h > > > > index ac331aa07cfa..a627fa69668e 100644 > > > > --- a/fs/ceph/super.h > > > > +++ b/fs/ceph/super.h > > > > @@ -1043,6 +1043,7 @@ static inline bool > > > > ceph_inode_is_shutdown(struct inode *inode) > > > > > > > > /* xattr.c */ > > > > int __ceph_setxattr(struct inode *, const char *, const void *, > > > > size_t, int); > > > > +int ceph_do_getvxattr(struct inode *inode, const char *name, void > > > > *value, size_t size); > > > > ssize_t __ceph_getxattr(struct inode *, const char *, void *, > > > > size_t); > > > > extern ssize_t ceph_listxattr(struct dentry *, char *, size_t); > > > > extern struct ceph_buffer *__ceph_build_xattrs_blob(struct > > > > ceph_inode_info *ci); > > > > diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c > > > > index fcf7dfdecf96..fdde8ffa71bb 100644 > > > > --- a/fs/ceph/xattr.c > > > > +++ b/fs/ceph/xattr.c > > > > @@ -918,6 +918,64 @@ static inline int __get_request_mask(struct > > > > inode *in) { > > > > return mask; > > > > } > > > > > > > > +static inline bool ceph_is_passthrough_vxattr(const char *name) > > > > +{ > > > > + const char *vxattr_list[] = { > > > > + "ceph.dir.pin", > > > > + "ceph.dir.pin.random", > > > > + "ceph.dir.pin.distributed", > > > > + "ceph.dir.layout", > > > > + "ceph.dir.layout.object_size", > > > > + "ceph.dir.layout.stripe_count", > > > > + "ceph.dir.layout.stripe_unit", > > > > + "ceph.dir.layout.pool", > > > > + "ceph.dir.layout.pool_name", > > > > + "ceph.dir.layout.pool_id", > > > > + "ceph.dir.layout.pool_namespace", > > > > + "ceph.file.layout", > > > > + "ceph.file.layout.object_size", > > > > + "ceph.file.layout.stripe_count", > > > > + "ceph.file.layout.stripe_unit", > > > > + "ceph.file.layout.pool", > > > > + "ceph.file.layout.pool_name", > > > > + "ceph.file.layout.pool_id", > > > > + "ceph.file.layout.pool_namespace", > > > > + }; > > > > + int i = 0; > > > > + int n = sizeof(vxattr_list)/sizeof(vxattr_list[0]); > > > > + > > > > + while (i < n) { > > > > + if (!strcmp(name, vxattr_list[i])) > > > > + return true; > > > > + i++; > > > > + } > > > > + return false; > > > > +} > > > > > > This part, I'm not so crazy about. This list will be hard to keep in > > > sync with the userland code and you're almost guaranteed to have a > > > mismatch between what the kernel and userland supports since they're > > > on > > > different release schedules. > > > > > > I think what we probably ought to do is run the ceph_match_vxattr > > > call > > > first, and if it doesn't match the name and the name starts with > > > "ceph.", then we'll send a GETVXATTR call to the MDS. > > > > > > Sound ok? > > > > > > > > > I was trying to preempt a getvxattr call if the full xattr name was > > invalid. > > Huh, why? That seems like the point of the whole bug. We need a way to > hand vxattrs that the client doesn't recognize off to the MDS so it can > satisfy the request. File and dir layout vxattrs are server-side xattrs. So, it seemed prudent to delegate them to the server. The idea was also to help identify layouts and their inheritance for a dir hierarchy or a file at the server side and possibly avoiding client round trips to the server for learning about the same (and maintain consistency?) Here's some discussion about the same: https://tracker.ceph.com/issues/51062#note-3 > > > I could just test for the prefixes: ceph.dir.pin, ceph.dir.layout and > > ceph.file.layout and send them over. Eventually, we'll get an ENODATA > > if xattr name validation fails on the MDS side. > > > > The problem with doing a ceph_match_vxattr() first is that it will > > succeed > > for any of these vxattrs, but we'll land in the same place as the one > > you've > > described in the tracker. > > The very idea of implementing getvxattr is to bypass the existing > > "cached" > > service mechanism for special vxattrs. > > > > I don't get it. What's the benefit of calling out to the MDS to ask for > ceph.file.layout.pool instead of just satisfying it from the info we > have? > > I'd prefer we just add a fallback for "ceph.*" vxattrs that for which we > don't have a local handler. See my explanation above. > > > > > > > > > + > > > > +/* check if the entire cluster supports the given feature */ > > > > +static inline bool ceph_cluster_has_feature(struct inode *inode, > > > > int feature_bit) > > > > +{ > > > > + int64_t i; > > > > + struct ceph_fs_client *fsc = ceph_inode_to_client(inode); > > > > + struct ceph_mds_session **sessions = fsc->mdsc->sessions; > > > > + int64_t num_sessions = atomic_read(&fsc->mdsc- > > > > >num_sessions); > > > > + > > > > + if (fsc->mdsc->stopping) > > > > + return false; > > > > + > > > > + if (!sessions) > > > > + return false; > > > > + > > > > + for (i = 0; i < num_sessions; i++) { > > > > + struct ceph_mds_session *session = sessions[i]; > > > > + if (!session) > > > > + return false; > > > > + if (!test_bit(feature_bit, &session->s_features)) > > > > + return false; > > > > + } > > > > + return true; > > > > +} > > > > + > > > > ssize_t __ceph_getxattr(struct inode *inode, const char *name, > > > > void *value, > > > > size_t size) > > > > { > > > > @@ -927,6 +985,13 @@ ssize_t __ceph_getxattr(struct inode *inode, > > > > const char *name, void *value, > > > > int req_mask; > > > > ssize_t err; > > > > > > > > + if (ceph_is_passthrough_vxattr(name) && > > > > + ceph_cluster_has_feature(inode, > > > > CEPHFS_FEATURE_GETVXATTR)) { > > > > + err = ceph_do_getvxattr(inode, name, value, size); > > > > + return err; > > > > + } > > > > + dout("vxattr is not passthrough or kclient doesn't support > > > > GETVXATTR\n"); > > > > + > > > > /* let's see if a virtual xattr was requested */ > > > > vxattr = ceph_match_vxattr(inode, name); > > > > if (vxattr) { > > > > diff --git a/include/linux/ceph/ceph_fs.h > > > > b/include/linux/ceph/ceph_fs.h > > > > index 7ad6c3d0db7d..66db21ac5f0c 100644 > > > > --- a/include/linux/ceph/ceph_fs.h > > > > +++ b/include/linux/ceph/ceph_fs.h > > > > @@ -328,6 +328,7 @@ enum { > > > > CEPH_MDS_OP_LOOKUPPARENT = 0x00103, > > > > CEPH_MDS_OP_LOOKUPINO = 0x00104, > > > > CEPH_MDS_OP_LOOKUPNAME = 0x00105, > > > > + CEPH_MDS_OP_GETVXATTR = 0x00106, > > > > > > > > CEPH_MDS_OP_SETXATTR = 0x01105, > > > > CEPH_MDS_OP_RMXATTR = 0x01106, > > > > > -- > Jeff Layton <jlayton@xxxxxxxxxx>
