LU-14405 mdt: read LMV with mdt_stripe_get()

mdt_path_current() reads LMV into mdt_thread_info.mti_xattr_buf,
whose size is static, and will return -ERANGE if LMV contains too
many stripes, instead it should call mdt_stripe_get(), the latter
will allocate dynamic memory for LMV.

Test-Parameters: mdtcount=8
Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: I1ed78f7a7f951fa5984e604a8773143a70b419e7
Reviewed-on: https://review.whamcloud.com/41452
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Yingjin Qian <qian@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/mdt/mdt_handler.c b/lustre/mdt/mdt_handler.c
index 87d7afe..0a6d779 100644 (file)
--- a/lustre/mdt/mdt_handler.c
+++ b/lustre/mdt/mdt_handler.c
@@ -6727,18 +6727,20 @@ static int mdt_path_current(struct mdt_thread_info *info,
                            struct getinfo_fid2path *fp,
                            struct lu_fid *root_fid)
 {
-       struct mdt_device       *mdt = info->mti_mdt;
-       struct mdt_object       *mdt_obj;
-       struct link_ea_header   *leh;
-       struct link_ea_entry    *lee;
-       struct lu_name          *tmpname = &info->mti_name;
-       struct lu_fid           *tmpfid = &info->mti_tmp_fid1;
-       struct lu_buf           *buf = &info->mti_big_buf;
-       char                    *ptr;
-       int                     reclen;
-       struct linkea_data      ldata = { NULL };
-       int                     rc = 0;
-       bool                    first = true;
+       struct mdt_device *mdt = info->mti_mdt;
+       struct lu_name *tmpname = &info->mti_name;
+       struct lu_fid *tmpfid = &info->mti_tmp_fid1;
+       struct lu_buf *buf = &info->mti_big_buf;
+       struct md_attr *ma = &info->mti_attr;
+       struct linkea_data ldata = { NULL };
+       bool first = true;
+       struct mdt_object *mdt_obj;
+       struct link_ea_header *leh;
+       struct link_ea_entry *lee;
+       char *ptr;
+       int reclen;
+       int rc = 0;
+
        ENTRY;
 
        /* temp buffer for path element, the buffer will be finally freed
@@ -6754,8 +6756,6 @@ static int mdt_path_current(struct mdt_thread_info *info,
        *tmpfid = fp->gf_fid = *mdt_object_fid(obj);
 
        while (!lu_fid_eq(root_fid, &fp->gf_fid)) {
-               struct lu_buf           lmv_buf;
-
                if (!lu_fid_eq(root_fid, &mdt->mdt_md_root_fid) &&
                    lu_fid_eq(&mdt->mdt_md_root_fid, &fp->gf_fid))
                        GOTO(out, rc = -ENOENT);
@@ -6803,22 +6803,23 @@ static int mdt_path_current(struct mdt_thread_info *info,
                                fp->gf_linkno++;
                }
 
-               lmv_buf.lb_buf = info->mti_xattr_buf;
-               lmv_buf.lb_len = sizeof(info->mti_xattr_buf);
                /* Check if it is slave stripes */
-               rc = mo_xattr_get(info->mti_env, mdt_object_child(mdt_obj),
-                                 &lmv_buf, XATTR_NAME_LMV);
+               rc = mdt_stripe_get(info, mdt_obj, ma, XATTR_NAME_LMV);
                mdt_object_put(info->mti_env, mdt_obj);
-               if (rc > 0) {
-                       union lmv_mds_md *lmm = lmv_buf.lb_buf;
+               if (rc < 0)
+                       GOTO(out, rc);
+
+               if (ma->ma_valid & MA_LMV) {
+                       struct lmv_mds_md_v1 *lmv = &ma->ma_lmv->lmv_md_v1;
+
+                       if (!lmv_is_sane2(lmv))
+                               GOTO(out, rc = -EBADF);
 
                        /* For slave stripes, get its master */
-                       if (le32_to_cpu(lmm->lmv_magic) == LMV_MAGIC_STRIPE) {
+                       if (le32_to_cpu(lmv->lmv_magic) == LMV_MAGIC_STRIPE) {
                                fp->gf_fid = *tmpfid;
                                continue;
                        }
-               } else if (rc < 0 && rc != -ENODATA) {
-                       GOTO(out, rc);
                }
 
                /* Pack the name in the end of the buffer */