LU-14490 lmv: striped directory as subdirectory mount

[fs/lustre-release.git] / lustre / mdt / mdt_handler.c

diff --git a/lustre/mdt/mdt_handler.c b/lustre/mdt/mdt_handler.c
index 0a6d779..462d522 100644 (file)
--- a/lustre/mdt/mdt_handler.c
+++ b/lustre/mdt/mdt_handler.c
@@ -276,6 +276,7 @@ static int mdt_lookup_fileset(struct mdt_thread_info *info, const char *fileset,
 {
        struct mdt_device *mdt = info->mti_mdt;
        struct lu_name *lname = &info->mti_name;
+       const char *start = fileset;
        char *filename = info->mti_filename;
        struct mdt_object *parent;
        u32 mode;
@@ -290,8 +291,8 @@ static int mdt_lookup_fileset(struct mdt_thread_info *info, const char *fileset,
         */
        *fid = mdt->mdt_md_root_fid;
 
-       while (rc == 0 && fileset != NULL && *fileset != '\0') {
-               const char *s1 = fileset;
+       while (rc == 0 && start != NULL && *start != '\0') {
+               const char *s1 = start;
                const char *s2;
 
                while (*++s1 == '/')
@@ -303,7 +304,7 @@ static int mdt_lookup_fileset(struct mdt_thread_info *info, const char *fileset,
                if (s2 == s1)
                        break;
 
-               fileset = s2;
+               start = s2;
 
                lname->ln_namelen = s2 - s1;
                if (lname->ln_namelen > NAME_MAX) {
@@ -339,9 +340,21 @@ static int mdt_lookup_fileset(struct mdt_thread_info *info, const char *fileset,
                        rc = PTR_ERR(parent);
                else {
                        mode = lu_object_attr(&parent->mot_obj);
-                       mdt_object_put(info->mti_env, parent);
-                       if (!S_ISDIR(mode))
+                       if (!S_ISDIR(mode)) {
                                rc = -ENOTDIR;
+                       } else if (mdt_is_remote_object(info, parent, parent)) {
+                               if (!mdt->mdt_enable_remote_subdir_mount) {
+                                       rc = -EREMOTE;
+                                       LCONSOLE_WARN("%s: subdir mount '%s' refused because 'enable_remote_subdir_mount=0': rc = %d\n",
+                                                     mdt_obd_name(mdt),
+                                                     fileset, rc);
+                               } else {
+                                       LCONSOLE_INFO("%s: subdir mount '%s' is remote and may be slow\n",
+                                                     mdt_obd_name(mdt),
+                                                     fileset);
+                               }
+                       }
+                       mdt_object_put(info->mti_env, parent);
                }
        }
 
@@ -5700,6 +5713,7 @@ static int mdt_init0(const struct lu_env *env, struct mdt_device *m,
        m->mdt_enable_chprojid_gid = 0;
        m->mdt_enable_remote_rename = 1;
        m->mdt_dir_restripe_nsonly = 1;
+       m->mdt_enable_remote_subdir_mount = 1;
 
        atomic_set(&m->mdt_mds_mds_conns, 0);
        atomic_set(&m->mdt_async_commit_count, 0);