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LU-13745 pcc: fall back normal splice read for detached file
[fs/lustre-release.git] / lustre / llite / pcc.c
index be3a9db..c51a735 100644 (file)
 
 struct kmem_cache *pcc_inode_slab;
 
-void pcc_super_init(struct pcc_super *super)
+int pcc_super_init(struct pcc_super *super)
 {
-       spin_lock_init(&super->pccs_lock);
+       struct cred *cred;
+
+       super->pccs_cred = cred = prepare_creds();
+       if (!cred)
+               return -ENOMEM;
+
+       /* Never override disk quota limits or use reserved space */
+       cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
+       init_rwsem(&super->pccs_rw_sem);
        INIT_LIST_HEAD(&super->pccs_datasets);
+       super->pccs_generation = 1;
+
+       return 0;
+}
+
+/* Rule based auto caching */
+static void pcc_id_list_free(struct list_head *id_list)
+{
+       struct pcc_match_id *id, *n;
+
+       list_for_each_entry_safe(id, n, id_list, pmi_linkage) {
+               list_del_init(&id->pmi_linkage);
+               OBD_FREE_PTR(id);
+       }
+}
+
+static void pcc_fname_list_free(struct list_head *fname_list)
+{
+       struct pcc_match_fname *fname, *n;
+
+       list_for_each_entry_safe(fname, n, fname_list, pmf_linkage) {
+               OBD_FREE(fname->pmf_name, strlen(fname->pmf_name) + 1);
+               list_del_init(&fname->pmf_linkage);
+               OBD_FREE_PTR(fname);
+       }
+}
+
+static void pcc_expression_free(struct pcc_expression *expr)
+{
+       LASSERT(expr->pe_field >= PCC_FIELD_UID &&
+               expr->pe_field < PCC_FIELD_MAX);
+       switch (expr->pe_field) {
+       case PCC_FIELD_UID:
+       case PCC_FIELD_GID:
+       case PCC_FIELD_PROJID:
+               pcc_id_list_free(&expr->pe_cond);
+               break;
+       case PCC_FIELD_FNAME:
+               pcc_fname_list_free(&expr->pe_cond);
+               break;
+       default:
+               LBUG();
+       }
+       OBD_FREE_PTR(expr);
+}
+
+static void pcc_conjunction_free(struct pcc_conjunction *conjunction)
+{
+       struct pcc_expression *expression, *n;
+
+       LASSERT(list_empty(&conjunction->pc_linkage));
+       list_for_each_entry_safe(expression, n,
+                                &conjunction->pc_expressions,
+                                pe_linkage) {
+               list_del_init(&expression->pe_linkage);
+               pcc_expression_free(expression);
+       }
+       OBD_FREE_PTR(conjunction);
+}
+
+static void pcc_rule_conds_free(struct list_head *cond_list)
+{
+       struct pcc_conjunction *conjunction, *n;
+
+       list_for_each_entry_safe(conjunction, n, cond_list, pc_linkage) {
+               list_del_init(&conjunction->pc_linkage);
+               pcc_conjunction_free(conjunction);
+       }
+}
+
+static void pcc_cmd_fini(struct pcc_cmd *cmd)
+{
+       if (cmd->pccc_cmd == PCC_ADD_DATASET) {
+               if (!list_empty(&cmd->u.pccc_add.pccc_conds))
+                       pcc_rule_conds_free(&cmd->u.pccc_add.pccc_conds);
+               if (cmd->u.pccc_add.pccc_conds_str)
+                       OBD_FREE(cmd->u.pccc_add.pccc_conds_str,
+                                strlen(cmd->u.pccc_add.pccc_conds_str) + 1);
+       }
+}
+
+#define PCC_DISJUNCTION_DELIM  (',')
+#define PCC_CONJUNCTION_DELIM  ('&')
+#define PCC_EXPRESSION_DELIM   ('=')
+
+static int
+pcc_fname_list_add(struct cfs_lstr *id, struct list_head *fname_list)
+{
+       struct pcc_match_fname *fname;
+
+       OBD_ALLOC_PTR(fname);
+       if (fname == NULL)
+               return -ENOMEM;
+
+       OBD_ALLOC(fname->pmf_name, id->ls_len + 1);
+       if (fname->pmf_name == NULL) {
+               OBD_FREE_PTR(fname);
+               return -ENOMEM;
+       }
+
+       memcpy(fname->pmf_name, id->ls_str, id->ls_len);
+       list_add_tail(&fname->pmf_linkage, fname_list);
+       return 0;
+}
+
+static int
+pcc_fname_list_parse(char *str, int len, struct list_head *fname_list)
+{
+       struct cfs_lstr src;
+       struct cfs_lstr res;
+       int rc = 0;
+
+       ENTRY;
+
+       src.ls_str = str;
+       src.ls_len = len;
+       INIT_LIST_HEAD(fname_list);
+       while (src.ls_str) {
+               rc = cfs_gettok(&src, ' ', &res);
+               if (rc == 0) {
+                       rc = -EINVAL;
+                       break;
+               }
+               rc = pcc_fname_list_add(&res, fname_list);
+               if (rc)
+                       break;
+       }
+       if (rc)
+               pcc_fname_list_free(fname_list);
+       RETURN(rc);
+}
+
+static int
+pcc_id_list_parse(char *str, int len, struct list_head *id_list,
+                 enum pcc_field type)
+{
+       struct cfs_lstr src;
+       struct cfs_lstr res;
+       int rc = 0;
+
+       ENTRY;
+
+       if (type != PCC_FIELD_UID && type != PCC_FIELD_GID &&
+           type != PCC_FIELD_PROJID)
+               RETURN(-EINVAL);
+
+       src.ls_str = str;
+       src.ls_len = len;
+       INIT_LIST_HEAD(id_list);
+       while (src.ls_str) {
+               struct pcc_match_id *id;
+               __u32 id_val;
+
+               if (cfs_gettok(&src, ' ', &res) == 0)
+                       GOTO(out, rc = -EINVAL);
+
+               if (!cfs_str2num_check(res.ls_str, res.ls_len,
+                                      &id_val, 0, (u32)~0U))
+                       GOTO(out, rc = -EINVAL);
+
+               OBD_ALLOC_PTR(id);
+               if (id == NULL)
+                       GOTO(out, rc = -ENOMEM);
+
+               id->pmi_id = id_val;
+               list_add_tail(&id->pmi_linkage, id_list);
+       }
+out:
+       if (rc)
+               pcc_id_list_free(id_list);
+       RETURN(rc);
+}
+
+static inline bool
+pcc_check_field(struct cfs_lstr *field, char *str)
+{
+       int len = strlen(str);
+
+       return (field->ls_len == len &&
+               strncmp(field->ls_str, str, len) == 0);
+}
+
+static int
+pcc_expression_parse(struct cfs_lstr *src, struct list_head *cond_list)
+{
+       struct pcc_expression *expr;
+       struct cfs_lstr field;
+       int rc = 0;
+
+       OBD_ALLOC_PTR(expr);
+       if (expr == NULL)
+               return -ENOMEM;
+
+       rc = cfs_gettok(src, PCC_EXPRESSION_DELIM, &field);
+       if (rc == 0 || src->ls_len <= 2 || src->ls_str[0] != '{' ||
+           src->ls_str[src->ls_len - 1] != '}')
+               GOTO(out, rc = -EINVAL);
+
+       /* Skip '{' and '}' */
+       src->ls_str++;
+       src->ls_len -= 2;
+
+       if (pcc_check_field(&field, "uid")) {
+               if (pcc_id_list_parse(src->ls_str,
+                                     src->ls_len,
+                                     &expr->pe_cond,
+                                     PCC_FIELD_UID) < 0)
+                       GOTO(out, rc = -EINVAL);
+               expr->pe_field = PCC_FIELD_UID;
+       } else if (pcc_check_field(&field, "gid")) {
+               if (pcc_id_list_parse(src->ls_str,
+                                     src->ls_len,
+                                     &expr->pe_cond,
+                                     PCC_FIELD_GID) < 0)
+                       GOTO(out, rc = -EINVAL);
+               expr->pe_field = PCC_FIELD_GID;
+       } else if (pcc_check_field(&field, "projid")) {
+               if (pcc_id_list_parse(src->ls_str,
+                                     src->ls_len,
+                                     &expr->pe_cond,
+                                     PCC_FIELD_PROJID) < 0)
+                       GOTO(out, rc = -EINVAL);
+               expr->pe_field = PCC_FIELD_PROJID;
+       } else if (pcc_check_field(&field, "fname")) {
+               if (pcc_fname_list_parse(src->ls_str,
+                                        src->ls_len,
+                                        &expr->pe_cond) < 0)
+                       GOTO(out, rc = -EINVAL);
+               expr->pe_field = PCC_FIELD_FNAME;
+       } else {
+               GOTO(out, rc = -EINVAL);
+       }
+
+       list_add_tail(&expr->pe_linkage, cond_list);
+       return 0;
+out:
+       OBD_FREE_PTR(expr);
+       return rc;
+}
+
+static int
+pcc_conjunction_parse(struct cfs_lstr *src, struct list_head *cond_list)
+{
+       struct pcc_conjunction *conjunction;
+       struct cfs_lstr expr;
+       int rc = 0;
+
+       OBD_ALLOC_PTR(conjunction);
+       if (conjunction == NULL)
+               return -ENOMEM;
+
+       INIT_LIST_HEAD(&conjunction->pc_expressions);
+       list_add_tail(&conjunction->pc_linkage, cond_list);
+
+       while (src->ls_str) {
+               rc = cfs_gettok(src, PCC_CONJUNCTION_DELIM, &expr);
+               if (rc == 0) {
+                       rc = -EINVAL;
+                       break;
+               }
+               rc = pcc_expression_parse(&expr,
+                                         &conjunction->pc_expressions);
+               if (rc)
+                       break;
+       }
+       return rc;
+}
+
+static int pcc_conds_parse(char *str, int len, struct list_head *cond_list)
+{
+       struct cfs_lstr src;
+       struct cfs_lstr res;
+       int rc = 0;
+
+       src.ls_str = str;
+       src.ls_len = len;
+       INIT_LIST_HEAD(cond_list);
+       while (src.ls_str) {
+               rc = cfs_gettok(&src, PCC_DISJUNCTION_DELIM, &res);
+               if (rc == 0) {
+                       rc = -EINVAL;
+                       break;
+               }
+               rc = pcc_conjunction_parse(&res, cond_list);
+               if (rc)
+                       break;
+       }
+       return rc;
+}
+
+static int pcc_id_parse(struct pcc_cmd *cmd, const char *id)
+{
+       int rc;
+
+       OBD_ALLOC(cmd->u.pccc_add.pccc_conds_str, strlen(id) + 1);
+       if (cmd->u.pccc_add.pccc_conds_str == NULL)
+               return -ENOMEM;
+
+       memcpy(cmd->u.pccc_add.pccc_conds_str, id, strlen(id));
+
+       rc = pcc_conds_parse(cmd->u.pccc_add.pccc_conds_str,
+                            strlen(cmd->u.pccc_add.pccc_conds_str),
+                            &cmd->u.pccc_add.pccc_conds);
+       if (rc)
+               pcc_cmd_fini(cmd);
+
+       return rc;
+}
+
+static int
+pcc_parse_value_pair(struct pcc_cmd *cmd, char *buffer)
+{
+       char *key, *val;
+       unsigned long id;
+       int rc;
+
+       val = buffer;
+       key = strsep(&val, "=");
+       if (val == NULL || strlen(val) == 0)
+               return -EINVAL;
+
+       /* Key of the value pair */
+       if (strcmp(key, "rwid") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id <= 0)
+                       return -EINVAL;
+               cmd->u.pccc_add.pccc_rwid = id;
+       } else if (strcmp(key, "roid") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id <= 0)
+                       return -EINVAL;
+               cmd->u.pccc_add.pccc_roid = id;
+       } else if (strcmp(key, "auto_attach") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id == 0)
+                       cmd->u.pccc_add.pccc_flags &= ~PCC_DATASET_AUTO_ATTACH;
+       } else if (strcmp(key, "open_attach") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id == 0)
+                       cmd->u.pccc_add.pccc_flags &= ~PCC_DATASET_OPEN_ATTACH;
+       } else if (strcmp(key, "io_attach") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id == 0)
+                       cmd->u.pccc_add.pccc_flags &= ~PCC_DATASET_IO_ATTACH;
+       } else if (strcmp(key, "stat_attach") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id == 0)
+                       cmd->u.pccc_add.pccc_flags &= ~PCC_DATASET_STAT_ATTACH;
+       } else if (strcmp(key, "rwpcc") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id > 0)
+                       cmd->u.pccc_add.pccc_flags |= PCC_DATASET_RWPCC;
+       } else if (strcmp(key, "ropcc") == 0) {
+               rc = kstrtoul(val, 10, &id);
+               if (rc)
+                       return rc;
+               if (id > 0)
+                       cmd->u.pccc_add.pccc_flags |= PCC_DATASET_ROPCC;
+       } else {
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int
+pcc_parse_value_pairs(struct pcc_cmd *cmd, char *buffer)
+{
+       char *val;
+       char *token;
+       int rc;
+
+       switch (cmd->pccc_cmd) {
+       case PCC_ADD_DATASET:
+               /* Enable auto attach by default */
+               cmd->u.pccc_add.pccc_flags |= PCC_DATASET_AUTO_ATTACH;
+               break;
+       case PCC_DEL_DATASET:
+       case PCC_CLEAR_ALL:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       val = buffer;
+       while (val != NULL && strlen(val) != 0) {
+               token = strsep(&val, " ");
+               rc = pcc_parse_value_pair(cmd, token);
+               if (rc)
+                       return rc;
+       }
+
+       switch (cmd->pccc_cmd) {
+       case PCC_ADD_DATASET:
+               if (cmd->u.pccc_add.pccc_flags & PCC_DATASET_RWPCC &&
+                   cmd->u.pccc_add.pccc_flags & PCC_DATASET_ROPCC)
+                       return -EINVAL;
+               /*
+                * By default, a PCC backend can provide caching service for
+                * both RW-PCC and RO-PCC.
+                */
+               if ((cmd->u.pccc_add.pccc_flags & PCC_DATASET_PCC_ALL) == 0)
+                       cmd->u.pccc_add.pccc_flags |= PCC_DATASET_PCC_ALL;
+
+               /* For RW-PCC, the value of @rwid must be non zero. */
+               if (cmd->u.pccc_add.pccc_flags & PCC_DATASET_RWPCC &&
+                   cmd->u.pccc_add.pccc_rwid == 0)
+                       return -EINVAL;
+
+               break;
+       case PCC_DEL_DATASET:
+       case PCC_CLEAR_ALL:
+               break;
+       default:
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static void
+pcc_dataset_rule_fini(struct pcc_match_rule *rule)
+{
+       if (!list_empty(&rule->pmr_conds))
+               pcc_rule_conds_free(&rule->pmr_conds);
+       LASSERT(rule->pmr_conds_str != NULL);
+       OBD_FREE(rule->pmr_conds_str, strlen(rule->pmr_conds_str) + 1);
+}
+
+static int
+pcc_dataset_rule_init(struct pcc_match_rule *rule, struct pcc_cmd *cmd)
+{
+       int rc = 0;
+
+       LASSERT(cmd->u.pccc_add.pccc_conds_str);
+       OBD_ALLOC(rule->pmr_conds_str,
+                 strlen(cmd->u.pccc_add.pccc_conds_str) + 1);
+       if (rule->pmr_conds_str == NULL)
+               return -ENOMEM;
+
+       memcpy(rule->pmr_conds_str,
+              cmd->u.pccc_add.pccc_conds_str,
+              strlen(cmd->u.pccc_add.pccc_conds_str));
+
+       INIT_LIST_HEAD(&rule->pmr_conds);
+       if (!list_empty(&cmd->u.pccc_add.pccc_conds))
+               rc = pcc_conds_parse(rule->pmr_conds_str,
+                                         strlen(rule->pmr_conds_str),
+                                         &rule->pmr_conds);
+
+       if (rc)
+               pcc_dataset_rule_fini(rule);
+
+       return rc;
+}
+
+/* Rule Matching */
+static int
+pcc_id_list_match(struct list_head *id_list, __u32 id_val)
+{
+       struct pcc_match_id *id;
+
+       list_for_each_entry(id, id_list, pmi_linkage) {
+               if (id->pmi_id == id_val)
+                       return 1;
+       }
+       return 0;
+}
+
+static bool
+cfs_match_wildcard(const char *pattern, const char *content)
+{
+       if (*pattern == '\0' && *content == '\0')
+               return true;
+
+       if (*pattern == '*' && *(pattern + 1) != '\0' && *content == '\0')
+               return false;
+
+       while (*pattern == *content) {
+               pattern++;
+               content++;
+               if (*pattern == '\0' && *content == '\0')
+                       return true;
+
+               if (*pattern == '*' && *(pattern + 1) != '\0' &&
+                   *content == '\0')
+                       return false;
+       }
+
+       if (*pattern == '*')
+               return (cfs_match_wildcard(pattern + 1, content) ||
+                       cfs_match_wildcard(pattern, content + 1));
+
+       return false;
+}
+
+static int
+pcc_fname_list_match(struct list_head *fname_list, const char *name)
+{
+       struct pcc_match_fname *fname;
+
+       list_for_each_entry(fname, fname_list, pmf_linkage) {
+               if (cfs_match_wildcard(fname->pmf_name, name))
+                       return 1;
+       }
+       return 0;
+}
+
+static int
+pcc_expression_match(struct pcc_expression *expr, struct pcc_matcher *matcher)
+{
+       switch (expr->pe_field) {
+       case PCC_FIELD_UID:
+               return pcc_id_list_match(&expr->pe_cond, matcher->pm_uid);
+       case PCC_FIELD_GID:
+               return pcc_id_list_match(&expr->pe_cond, matcher->pm_gid);
+       case PCC_FIELD_PROJID:
+               return pcc_id_list_match(&expr->pe_cond, matcher->pm_projid);
+       case PCC_FIELD_FNAME:
+               return pcc_fname_list_match(&expr->pe_cond,
+                                           matcher->pm_name->name);
+       default:
+               return 0;
+       }
+}
+
+static int
+pcc_conjunction_match(struct pcc_conjunction *conjunction,
+                     struct pcc_matcher *matcher)
+{
+       struct pcc_expression *expr;
+       int matched;
+
+       list_for_each_entry(expr, &conjunction->pc_expressions, pe_linkage) {
+               matched = pcc_expression_match(expr, matcher);
+               if (!matched)
+                       return 0;
+       }
+
+       return 1;
+}
+
+static int
+pcc_cond_match(struct pcc_match_rule *rule, struct pcc_matcher *matcher)
+{
+       struct pcc_conjunction *conjunction;
+       int matched;
+
+       list_for_each_entry(conjunction, &rule->pmr_conds, pc_linkage) {
+               matched = pcc_conjunction_match(conjunction, matcher);
+               if (matched)
+                       return 1;
+       }
+
+       return 0;
+}
+
+struct pcc_dataset*
+pcc_dataset_match_get(struct pcc_super *super, struct pcc_matcher *matcher)
+{
+       struct pcc_dataset *dataset;
+       struct pcc_dataset *selected = NULL;
+
+       down_read(&super->pccs_rw_sem);
+       list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
+               if (!(dataset->pccd_flags & PCC_DATASET_RWPCC))
+                       continue;
+
+               if (pcc_cond_match(&dataset->pccd_rule, matcher)) {
+                       atomic_inc(&dataset->pccd_refcount);
+                       selected = dataset;
+                       break;
+               }
+       }
+       up_read(&super->pccs_rw_sem);
+       if (selected)
+               CDEBUG(D_CACHE, "PCC create, matched %s - %d:%d:%d:%s\n",
+                      dataset->pccd_rule.pmr_conds_str,
+                      matcher->pm_uid, matcher->pm_gid,
+                      matcher->pm_projid, matcher->pm_name->name);
+
+       return selected;
 }
 
 /**
  * pcc_dataset_add - Add a Cache policy to control which files need be
  * cached and where it will be cached.
  *
- * @super: superblock of pcc
- * @pathname: root path of pcc
- * @id: HSM archive ID
- * @projid: files with specified project ID will be cached.
+ * @super:     superblock of pcc
+ * @cmd:       pcc command
  */
 static int
-pcc_dataset_add(struct pcc_super *super, const char *pathname,
-               __u32 archive_id, __u32 projid)
+pcc_dataset_add(struct pcc_super *super, struct pcc_cmd *cmd)
 {
-       int rc;
+       char *pathname = cmd->pccc_pathname;
        struct pcc_dataset *dataset;
        struct pcc_dataset *tmp;
        bool found = false;
+       int rc;
 
        OBD_ALLOC_PTR(dataset);
        if (dataset == NULL)
@@ -146,20 +747,31 @@ pcc_dataset_add(struct pcc_super *super, const char *pathname,
                return rc;
        }
        strncpy(dataset->pccd_pathname, pathname, PATH_MAX);
-       dataset->pccd_id = archive_id;
-       dataset->pccd_projid = projid;
+       dataset->pccd_rwid = cmd->u.pccc_add.pccc_rwid;
+       dataset->pccd_roid = cmd->u.pccc_add.pccc_roid;
+       dataset->pccd_flags = cmd->u.pccc_add.pccc_flags;
        atomic_set(&dataset->pccd_refcount, 1);
 
-       spin_lock(&super->pccs_lock);
+       rc = pcc_dataset_rule_init(&dataset->pccd_rule, cmd);
+       if (rc) {
+               pcc_dataset_put(dataset);
+               return rc;
+       }
+
+       down_write(&super->pccs_rw_sem);
        list_for_each_entry(tmp, &super->pccs_datasets, pccd_linkage) {
-               if (tmp->pccd_id == archive_id) {
+               if (strcmp(tmp->pccd_pathname, pathname) == 0 ||
+                   (dataset->pccd_rwid != 0 &&
+                    dataset->pccd_rwid == tmp->pccd_rwid) ||
+                   (dataset->pccd_roid != 0 &&
+                    dataset->pccd_roid == tmp->pccd_roid)) {
                        found = true;
                        break;
                }
        }
        if (!found)
                list_add(&dataset->pccd_linkage, &super->pccs_datasets);
-       spin_unlock(&super->pccs_lock);
+       up_write(&super->pccs_rw_sem);
 
        if (found) {
                pcc_dataset_put(dataset);
@@ -170,32 +782,31 @@ pcc_dataset_add(struct pcc_super *super, const char *pathname,
 }
 
 struct pcc_dataset *
-pcc_dataset_get(struct pcc_super *super, __u32 projid, __u32 archive_id)
+pcc_dataset_get(struct pcc_super *super, enum lu_pcc_type type, __u32 id)
 {
        struct pcc_dataset *dataset;
        struct pcc_dataset *selected = NULL;
 
-       if (projid == 0 && archive_id == 0)
+       if (id == 0)
                return NULL;
 
        /*
-        * archive ID is unique in the list, projid might be duplicate,
+        * archive ID (read-write ID) or read-only ID is unique in the list,
         * we just return last added one as first priority.
         */
-       spin_lock(&super->pccs_lock);
+       down_read(&super->pccs_rw_sem);
        list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
-               if (projid && dataset->pccd_projid != projid)
-                       continue;
-               if (archive_id && dataset->pccd_id != archive_id)
+               if (type == LU_PCC_READWRITE && (dataset->pccd_rwid != id ||
+                   !(dataset->pccd_flags & PCC_DATASET_RWPCC)))
                        continue;
                atomic_inc(&dataset->pccd_refcount);
                selected = dataset;
                break;
        }
-       spin_unlock(&super->pccs_lock);
+       up_read(&super->pccs_rw_sem);
        if (selected)
-               CDEBUG(D_CACHE, "matched projid %u, PCC create\n",
-                      selected->pccd_projid);
+               CDEBUG(D_CACHE, "matched id %u, PCC mode %d\n", id, type);
+
        return selected;
 }
 
@@ -203,6 +814,7 @@ void
 pcc_dataset_put(struct pcc_dataset *dataset)
 {
        if (atomic_dec_and_test(&dataset->pccd_refcount)) {
+               pcc_dataset_rule_fini(&dataset->pccd_rule);
                path_put(&dataset->pccd_path);
                OBD_FREE_PTR(dataset);
        }
@@ -215,17 +827,18 @@ pcc_dataset_del(struct pcc_super *super, char *pathname)
        struct pcc_dataset *dataset;
        int rc = -ENOENT;
 
-       spin_lock(&super->pccs_lock);
+       down_write(&super->pccs_rw_sem);
        list_for_each_safe(l, tmp, &super->pccs_datasets) {
                dataset = list_entry(l, struct pcc_dataset, pccd_linkage);
                if (strcmp(dataset->pccd_pathname, pathname) == 0) {
-                       list_del(&dataset->pccd_linkage);
+                       list_del_init(&dataset->pccd_linkage);
                        pcc_dataset_put(dataset);
+                       super->pccs_generation++;
                        rc = 0;
                        break;
                }
        }
-       spin_unlock(&super->pccs_lock);
+       up_write(&super->pccs_rw_sem);
        return rc;
 }
 
@@ -233,8 +846,9 @@ static void
 pcc_dataset_dump(struct pcc_dataset *dataset, struct seq_file *m)
 {
        seq_printf(m, "%s:\n", dataset->pccd_pathname);
-       seq_printf(m, "  rwid: %u\n", dataset->pccd_id);
-       seq_printf(m, "  autocache: projid=%u\n", dataset->pccd_projid);
+       seq_printf(m, "  rwid: %u\n", dataset->pccd_rwid);
+       seq_printf(m, "  flags: %x\n", dataset->pccd_flags);
+       seq_printf(m, "  autocache: %s\n", dataset->pccd_rule.pmr_conds_str);
 }
 
 int
@@ -242,25 +856,33 @@ pcc_super_dump(struct pcc_super *super, struct seq_file *m)
 {
        struct pcc_dataset *dataset;
 
-       spin_lock(&super->pccs_lock);
+       down_read(&super->pccs_rw_sem);
        list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
                pcc_dataset_dump(dataset, m);
        }
-       spin_unlock(&super->pccs_lock);
+       up_read(&super->pccs_rw_sem);
        return 0;
 }
 
-void pcc_super_fini(struct pcc_super *super)
+static void pcc_remove_datasets(struct pcc_super *super)
 {
        struct pcc_dataset *dataset, *tmp;
 
+       down_write(&super->pccs_rw_sem);
        list_for_each_entry_safe(dataset, tmp,
                                 &super->pccs_datasets, pccd_linkage) {
                list_del(&dataset->pccd_linkage);
                pcc_dataset_put(dataset);
        }
+       super->pccs_generation++;
+       up_write(&super->pccs_rw_sem);
 }
 
+void pcc_super_fini(struct pcc_super *super)
+{
+       pcc_remove_datasets(super);
+       put_cred(super->pccs_cred);
+}
 
 static bool pathname_is_valid(const char *pathname)
 {
@@ -277,7 +899,6 @@ pcc_cmd_parse(char *buffer, unsigned long count)
        static struct pcc_cmd *cmd;
        char *token;
        char *val;
-       unsigned long tmp;
        int rc = 0;
 
        OBD_ALLOC_PTR(cmd);
@@ -311,28 +932,35 @@ pcc_cmd_parse(char *buffer, unsigned long count)
        cmd->pccc_pathname = token;
 
        if (cmd->pccc_cmd == PCC_ADD_DATASET) {
-               /* archive ID */
-               token = strsep(&val, " ");
-               if (val == NULL)
+               /* List of ID */
+               LASSERT(val);
+               token = val;
+               val = strrchr(token, '}');
+               if (!val)
                        GOTO(out_free_cmd, rc = -EINVAL);
 
-               rc = kstrtoul(token, 10, &tmp);
-               if (rc != 0)
-                       GOTO(out_free_cmd, rc = -EINVAL);
-               if (tmp == 0)
+               /* Skip '}' */
+               val++;
+               if (*val == '\0') {
+                       val = NULL;
+               } else if (*val == ' ') {
+                       *val = '\0';
+                       val++;
+               } else {
                        GOTO(out_free_cmd, rc = -EINVAL);
-               cmd->u.pccc_add.pccc_id = tmp;
+               }
 
-               token = val;
-               rc = kstrtoul(token, 10, &tmp);
-               if (rc != 0)
-                       GOTO(out_free_cmd, rc = -EINVAL);
-               if (tmp == 0)
-                       GOTO(out_free_cmd, rc = -EINVAL);
-               cmd->u.pccc_add.pccc_projid = tmp;
-       }
+               rc = pcc_id_parse(cmd, token);
+               if (rc)
+                       GOTO(out_free_cmd, rc);
 
+               rc = pcc_parse_value_pairs(cmd, val);
+               if (rc)
+                       GOTO(out_cmd_fini, rc = -EINVAL);
+       }
        goto out;
+out_cmd_fini:
+       pcc_cmd_fini(cmd);
 out_free_cmd:
        OBD_FREE_PTR(cmd);
 out:
@@ -353,21 +981,20 @@ int pcc_cmd_handle(char *buffer, unsigned long count,
 
        switch (cmd->pccc_cmd) {
        case PCC_ADD_DATASET:
-               rc = pcc_dataset_add(super, cmd->pccc_pathname,
-                                     cmd->u.pccc_add.pccc_id,
-                                     cmd->u.pccc_add.pccc_projid);
+               rc = pcc_dataset_add(super, cmd);
                break;
        case PCC_DEL_DATASET:
                rc = pcc_dataset_del(super, cmd->pccc_pathname);
                break;
        case PCC_CLEAR_ALL:
-               pcc_super_fini(super);
+               pcc_remove_datasets(super);
                break;
        default:
                rc = -EINVAL;
                break;
        }
 
+       pcc_cmd_fini(cmd);
        OBD_FREE_PTR(cmd);
        return rc;
 }
@@ -403,66 +1030,420 @@ static void pcc_inode_fini(struct pcc_inode *pcci)
        lli->lli_pcc_inode = NULL;
 }
 
-static void pcc_inode_get(struct pcc_inode *pcci)
+static void pcc_inode_get(struct pcc_inode *pcci)
+{
+       atomic_inc(&pcci->pcci_refcount);
+}
+
+static void pcc_inode_put(struct pcc_inode *pcci)
+{
+       if (atomic_dec_and_test(&pcci->pcci_refcount))
+               pcc_inode_fini(pcci);
+}
+
+void pcc_inode_free(struct inode *inode)
+{
+       struct pcc_inode *pcci = ll_i2pcci(inode);
+
+       if (pcci) {
+               WARN_ON(atomic_read(&pcci->pcci_refcount) > 1);
+               pcc_inode_put(pcci);
+       }
+}
+
+/*
+ * TODO:
+ * As Andreas suggested, we'd better use new layout to
+ * reduce overhead:
+ * (fid->f_oid >> 16 & oxFFFF)/FID
+ */
+#define MAX_PCC_DATABASE_PATH (6 * 5 + FID_NOBRACE_LEN + 1)
+static int pcc_fid2dataset_path(char *buf, int sz, struct lu_fid *fid)
+{
+       return snprintf(buf, sz, "%04x/%04x/%04x/%04x/%04x/%04x/"
+                       DFID_NOBRACE,
+                       (fid)->f_oid       & 0xFFFF,
+                       (fid)->f_oid >> 16 & 0xFFFF,
+                       (unsigned int)((fid)->f_seq       & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
+                       PFID(fid));
+}
+
+static inline const struct cred *pcc_super_cred(struct super_block *sb)
+{
+       return ll_s2sbi(sb)->ll_pcc_super.pccs_cred;
+}
+
+void pcc_file_init(struct pcc_file *pccf)
+{
+       pccf->pccf_file = NULL;
+       pccf->pccf_type = LU_PCC_NONE;
+}
+
+static inline bool pcc_auto_attach_enabled(enum pcc_dataset_flags flags,
+                                          enum pcc_io_type iot)
+{
+       if (iot == PIT_OPEN)
+               return flags & PCC_DATASET_OPEN_ATTACH;
+       if (iot == PIT_GETATTR)
+               return flags & PCC_DATASET_STAT_ATTACH;
+       else
+               return flags & PCC_DATASET_AUTO_ATTACH;
+}
+
+static const char pcc_xattr_layout[] = XATTR_USER_PREFIX "PCC.layout";
+
+static int pcc_layout_xattr_set(struct pcc_inode *pcci, __u32 gen)
+{
+       struct dentry *pcc_dentry = pcci->pcci_path.dentry;
+       struct ll_inode_info *lli = pcci->pcci_lli;
+       int rc;
+
+       ENTRY;
+
+       if (!(lli->lli_pcc_dsflags & PCC_DATASET_AUTO_ATTACH))
+               RETURN(0);
+
+       rc = ll_vfs_setxattr(pcc_dentry, pcc_dentry->d_inode, pcc_xattr_layout,
+                            &gen, sizeof(gen), 0);
+
+       RETURN(rc);
+}
+
+static int pcc_get_layout_info(struct inode *inode, struct cl_layout *clt)
+{
+       struct lu_env *env;
+       struct ll_inode_info *lli = ll_i2info(inode);
+       __u16 refcheck;
+       int rc;
+
+       ENTRY;
+
+       if (!lli->lli_clob)
+               RETURN(-EINVAL);
+
+       env = cl_env_get(&refcheck);
+       if (IS_ERR(env))
+               RETURN(PTR_ERR(env));
+
+       rc = cl_object_layout_get(env, lli->lli_clob, clt);
+       if (rc)
+               CDEBUG(D_INODE, "Cannot get layout for "DFID"\n",
+                      PFID(ll_inode2fid(inode)));
+
+       cl_env_put(env, &refcheck);
+       RETURN(rc);
+}
+
+static int pcc_fid2dataset_fullpath(char *buf, int sz, struct lu_fid *fid,
+                                   struct pcc_dataset *dataset)
+{
+       return snprintf(buf, sz, "%s/%04x/%04x/%04x/%04x/%04x/%04x/"
+                       DFID_NOBRACE,
+                       dataset->pccd_pathname,
+                       (fid)->f_oid       & 0xFFFF,
+                       (fid)->f_oid >> 16 & 0xFFFF,
+                       (unsigned int)((fid)->f_seq       & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
+                       (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
+                       PFID(fid));
+}
+
+/* Must be called with pcci->pcci_lock held */
+static void pcc_inode_attach_init(struct pcc_dataset *dataset,
+                                 struct pcc_inode *pcci,
+                                 struct dentry *dentry,
+                                 enum lu_pcc_type type)
+{
+       pcci->pcci_path.mnt = mntget(dataset->pccd_path.mnt);
+       pcci->pcci_path.dentry = dentry;
+       LASSERT(atomic_read(&pcci->pcci_refcount) == 0);
+       atomic_set(&pcci->pcci_refcount, 1);
+       pcci->pcci_type = type;
+       pcci->pcci_attr_valid = false;
+}
+
+static inline void pcc_inode_dsflags_set(struct ll_inode_info *lli,
+                                        struct pcc_dataset *dataset)
+{
+       lli->lli_pcc_generation = ll_info2pccs(lli)->pccs_generation;
+       lli->lli_pcc_dsflags = dataset->pccd_flags;
+}
+
+static void pcc_inode_attach_set(struct pcc_super *super,
+                                struct pcc_dataset *dataset,
+                                struct ll_inode_info *lli,
+                                struct pcc_inode *pcci,
+                                struct dentry *dentry,
+                                enum lu_pcc_type type)
+{
+       pcc_inode_init(pcci, lli);
+       pcc_inode_attach_init(dataset, pcci, dentry, type);
+       down_read(&super->pccs_rw_sem);
+       pcc_inode_dsflags_set(lli, dataset);
+       up_read(&super->pccs_rw_sem);
+}
+
+static inline void pcc_layout_gen_set(struct pcc_inode *pcci,
+                                     __u32 gen)
+{
+       pcci->pcci_layout_gen = gen;
+}
+
+static inline bool pcc_inode_has_layout(struct pcc_inode *pcci)
 {
-       atomic_inc(&pcci->pcci_refcount);
+       return pcci->pcci_layout_gen != CL_LAYOUT_GEN_NONE;
 }
 
-static void pcc_inode_put(struct pcc_inode *pcci)
+static int pcc_try_dataset_attach(struct inode *inode, __u32 gen,
+                                 enum lu_pcc_type type,
+                                 struct pcc_dataset *dataset,
+                                 bool *cached)
 {
-       if (atomic_dec_and_test(&pcci->pcci_refcount))
-               pcc_inode_fini(pcci);
+       struct ll_inode_info *lli = ll_i2info(inode);
+       struct pcc_inode *pcci = lli->lli_pcc_inode;
+       const struct cred *old_cred;
+       struct dentry *pcc_dentry;
+       struct path path;
+       char *pathname;
+       __u32 pcc_gen;
+       int rc;
+
+       ENTRY;
+
+       if (type == LU_PCC_READWRITE &&
+           !(dataset->pccd_flags & PCC_DATASET_RWPCC))
+               RETURN(0);
+
+       OBD_ALLOC(pathname, PATH_MAX);
+       if (pathname == NULL)
+               RETURN(-ENOMEM);
+
+       pcc_fid2dataset_fullpath(pathname, PATH_MAX, &lli->lli_fid, dataset);
+
+       old_cred = override_creds(pcc_super_cred(inode->i_sb));
+       rc = kern_path(pathname, LOOKUP_FOLLOW, &path);
+       if (rc)
+               /* ignore this error */
+               GOTO(out, rc = 0);
+
+       pcc_dentry = path.dentry;
+       rc = ll_vfs_getxattr(pcc_dentry, pcc_dentry->d_inode, pcc_xattr_layout,
+                            &pcc_gen, sizeof(pcc_gen));
+       if (rc < 0)
+               /* ignore this error */
+               GOTO(out_put_path, rc = 0);
+
+       rc = 0;
+       /* The file is still valid cached in PCC, attach it immediately. */
+       if (pcc_gen == gen) {
+               CDEBUG(D_CACHE, DFID" L.Gen (%d) consistent, auto attached.\n",
+                      PFID(&lli->lli_fid), gen);
+               if (!pcci) {
+                       OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
+                       if (pcci == NULL)
+                               GOTO(out_put_path, rc = -ENOMEM);
+
+                       pcc_inode_init(pcci, lli);
+                       dget(pcc_dentry);
+                       pcc_inode_attach_init(dataset, pcci, pcc_dentry, type);
+               } else {
+                       /*
+                        * This happened when a file was once attached into
+                        * PCC, and some processes keep this file opened
+                        * (pcci->refcount > 1) and corresponding PCC file
+                        * without any I/O activity, and then this file was
+                        * detached by the manual detach command or the
+                        * revocation of the layout lock (i.e. cached LRU lock
+                        * shrinking).
+                        */
+                       pcc_inode_get(pcci);
+                       pcci->pcci_type = type;
+               }
+               pcc_inode_dsflags_set(lli, dataset);
+               pcc_layout_gen_set(pcci, gen);
+               *cached = true;
+       }
+out_put_path:
+       path_put(&path);
+out:
+       revert_creds(old_cred);
+       OBD_FREE(pathname, PATH_MAX);
+       RETURN(rc);
 }
 
-void pcc_inode_free(struct inode *inode)
+static int pcc_try_datasets_attach(struct inode *inode, enum pcc_io_type iot,
+                                  __u32 gen, enum lu_pcc_type type,
+                                  bool *cached)
 {
-       struct pcc_inode *pcci = ll_i2pcci(inode);
+       struct pcc_super *super = &ll_i2sbi(inode)->ll_pcc_super;
+       struct ll_inode_info *lli = ll_i2info(inode);
+       struct pcc_dataset *dataset = NULL, *tmp;
+       int rc = 0;
 
-       if (pcci) {
-               WARN_ON(atomic_read(&pcci->pcci_refcount) > 1);
-               pcc_inode_put(pcci);
+       ENTRY;
+
+       down_read(&super->pccs_rw_sem);
+       list_for_each_entry_safe(dataset, tmp,
+                                &super->pccs_datasets, pccd_linkage) {
+               if (!pcc_auto_attach_enabled(dataset->pccd_flags, iot))
+                       break;
+
+               rc = pcc_try_dataset_attach(inode, gen, type, dataset, cached);
+               if (rc < 0 || (!rc && *cached))
+                       break;
+       }
+
+       /*
+        * Update the saved dataset flags for the inode accordingly if failed.
+        */
+       if (!rc && !*cached) {
+               /*
+                * Currently auto attach strategy for a PCC backend is
+                * unchangeable once once it was added into the PCC datasets on
+                * a client as the support to change auto attach strategy is
+                * not implemented yet.
+                */
+               /*
+                * If tried to attach from one PCC backend:
+                * @lli_pcc_generation > 0:
+                * 1) The file was once attached into PCC, but now the
+                * corresponding PCC backend should be removed from the client;
+                * 2) The layout generation was changed, the data has been
+                * restored;
+                * 3) The corresponding PCC copy is not existed on PCC
+                * @lli_pcc_generation == 0:
+                * The file is never attached into PCC but in a HSM released
+                * state, or once attached into PCC but the inode was evicted
+                * from icache later.
+                * Set the saved dataset flags with PCC_DATASET_NONE. Then this
+                * file will skip from the candidates to try auto attach until
+                * the file is attached into PCC again.
+                *
+                * If the file was never attached into PCC, or once attached but
+                * its inode was evicted from icache (lli_pcc_generation == 0),
+                * or the corresponding dataset was removed from the client,
+                * set the saved dataset flags with PCC_DATASET_NONE.
+                *
+                * TODO: If the file was once attached into PCC but not try to
+                * auto attach due to the change of the configuration parameters
+                * for this dataset (i.e. change from auto attach enabled to
+                * auto attach disabled for this dataset), update the saved
+                * dataset flags with the found one.
+                */
+               lli->lli_pcc_dsflags = PCC_DATASET_NONE;
        }
+       up_read(&super->pccs_rw_sem);
+
+       RETURN(rc);
 }
 
 /*
- * TODO:
- * As Andreas suggested, we'd better use new layout to
- * reduce overhead:
- * (fid->f_oid >> 16 & oxFFFF)/FID
+ * TODO: For RW-PCC, it is desirable to store HSM info as a layout (LU-10606).
+ * Thus the client can get archive ID from the layout directly. When try to
+ * attach the file automatically which is in HSM released state (according to
+ * LOV_PATTERN_F_RELEASED in the layout), it can determine whether the file is
+ * valid cached on PCC more precisely according to the @rwid (archive ID) in
+ * the PCC dataset and the archive ID in HSM attrs.
  */
-#define MAX_PCC_DATABASE_PATH (6 * 5 + FID_NOBRACE_LEN + 1)
-static int pcc_fid2dataset_path(char *buf, int sz, struct lu_fid *fid)
+static int pcc_try_auto_attach(struct inode *inode, bool *cached,
+                              enum pcc_io_type iot)
 {
-       return snprintf(buf, sz, "%04x/%04x/%04x/%04x/%04x/%04x/"
-                       DFID_NOBRACE,
-                       (fid)->f_oid       & 0xFFFF,
-                       (fid)->f_oid >> 16 & 0xFFFF,
-                       (unsigned int)((fid)->f_seq       & 0xFFFF),
-                       (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
-                       (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
-                       (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
-                       PFID(fid));
-}
+       struct pcc_super *super = &ll_i2sbi(inode)->ll_pcc_super;
+       struct cl_layout clt = {
+               .cl_layout_gen = 0,
+               .cl_is_released = false,
+       };
+       struct ll_inode_info *lli = ll_i2info(inode);
+       __u32 gen;
+       int rc;
 
-void pcc_file_init(struct pcc_file *pccf)
-{
-       pccf->pccf_file = NULL;
-       pccf->pccf_type = LU_PCC_NONE;
+       ENTRY;
+
+       /*
+        * Quick check whether there is PCC device.
+        */
+       if (list_empty(&super->pccs_datasets))
+               RETURN(0);
+
+       /*
+        * The file layout lock was cancelled. And this open does not
+        * obtain valid layout lock from MDT (i.e. the file is being
+        * HSM restoring).
+        */
+       if (iot == PIT_OPEN) {
+               if (ll_layout_version_get(lli) == CL_LAYOUT_GEN_NONE)
+                       RETURN(0);
+       } else {
+               rc = ll_layout_refresh(inode, &gen);
+               if (rc)
+                       RETURN(rc);
+       }
+
+       rc = pcc_get_layout_info(inode, &clt);
+       if (rc)
+               RETURN(rc);
+
+       if (iot != PIT_OPEN && gen != clt.cl_layout_gen) {
+               CDEBUG(D_CACHE, DFID" layout changed from %d to %d.\n",
+                      PFID(ll_inode2fid(inode)), gen, clt.cl_layout_gen);
+               RETURN(-EINVAL);
+       }
+
+       if (clt.cl_is_released)
+               rc = pcc_try_datasets_attach(inode, iot, clt.cl_layout_gen,
+                                            LU_PCC_READWRITE, cached);
+
+       RETURN(rc);
 }
 
-static inline bool pcc_inode_has_layout(struct pcc_inode *pcci)
+static inline bool pcc_may_auto_attach(struct inode *inode,
+                                      enum pcc_io_type iot)
 {
-       return pcci->pcci_layout_gen != CL_LAYOUT_GEN_NONE;
+       struct ll_inode_info *lli = ll_i2info(inode);
+       struct pcc_super *super = ll_i2pccs(inode);
+
+       /* Known the file was not in any PCC backend. */
+       if (lli->lli_pcc_dsflags & PCC_DATASET_NONE)
+               return false;
+
+       /*
+        * lli_pcc_generation == 0 means that the file was never attached into
+        * PCC, or may be once attached into PCC but detached as the inode is
+        * evicted from icache (i.e. "echo 3 > /proc/sys/vm/drop_caches" or
+        * icache shrinking due to the memory pressure), which will cause the
+        * file detach from PCC when releasing the inode from icache.
+        * In either case, we still try to attach.
+        */
+       /* lli_pcc_generation == 0, or the PCC setting was changed,
+        * or there is no PCC setup on the client and the try will return
+        * immediately in pcc_try_auto_attach().
+        */
+       if (super->pccs_generation != lli->lli_pcc_generation)
+               return true;
+
+       /* The cached setting @lli_pcc_dsflags is valid */
+       if (iot == PIT_OPEN)
+               return lli->lli_pcc_dsflags & PCC_DATASET_OPEN_ATTACH;
+
+       if (iot == PIT_GETATTR)
+               return lli->lli_pcc_dsflags & PCC_DATASET_STAT_ATTACH;
+
+       return lli->lli_pcc_dsflags & PCC_DATASET_IO_ATTACH;
 }
 
 int pcc_file_open(struct inode *inode, struct file *file)
 {
        struct pcc_inode *pcci;
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_inode_info *lli = ll_i2info(inode);
+       struct ll_file_data *fd = file->private_data;
        struct pcc_file *pccf = &fd->fd_pcc_file;
        struct file *pcc_file;
        struct path *path;
-       struct qstr *dname;
+       bool cached = false;
        int rc = 0;
 
        ENTRY;
@@ -472,26 +1453,29 @@ int pcc_file_open(struct inode *inode, struct file *file)
 
        pcc_inode_lock(inode);
        pcci = ll_i2pcci(inode);
-       if (!pcci)
-               GOTO(out_unlock, rc = 0);
 
-       if (atomic_read(&pcci->pcci_refcount) == 0 ||
-           !pcc_inode_has_layout(pcci))
+       if (lli->lli_pcc_state & PCC_STATE_FL_ATTACHING)
                GOTO(out_unlock, rc = 0);
 
+       if (!pcci || !pcc_inode_has_layout(pcci)) {
+               if (pcc_may_auto_attach(inode, PIT_OPEN))
+                       rc = pcc_try_auto_attach(inode, &cached, PIT_OPEN);
+
+               if (rc < 0 || !cached)
+                       GOTO(out_unlock, rc);
+
+               if (!pcci)
+                       pcci = ll_i2pcci(inode);
+       }
+
        pcc_inode_get(pcci);
        WARN_ON(pccf->pccf_file);
 
        path = &pcci->pcci_path;
-       dname = &path->dentry->d_name;
-       CDEBUG(D_CACHE, "opening pcc file '%.*s'\n", dname->len,
-              dname->name);
-#ifdef HAVE_DENTRY_OPEN_USE_PATH
-       pcc_file = dentry_open(path, file->f_flags, current_cred());
-#else
-       pcc_file = dentry_open(path->dentry, path->mnt,
-                              file->f_flags, current_cred());
-#endif
+       CDEBUG(D_CACHE, "opening pcc file '%pd'\n", path->dentry);
+
+       pcc_file = dentry_open(path, file->f_flags,
+                              pcc_super_cred(inode->i_sb));
        if (IS_ERR_OR_NULL(pcc_file)) {
                rc = pcc_file == NULL ? -EINVAL : PTR_ERR(pcc_file);
                pcc_inode_put(pcci);
@@ -508,10 +1492,9 @@ out_unlock:
 void pcc_file_release(struct inode *inode, struct file *file)
 {
        struct pcc_inode *pcci;
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct pcc_file *pccf;
        struct path *path;
-       struct qstr *dname;
 
        ENTRY;
 
@@ -526,9 +1509,7 @@ void pcc_file_release(struct inode *inode, struct file *file)
        pcci = ll_i2pcci(inode);
        LASSERT(pcci);
        path = &pcci->pcci_path;
-       dname = &path->dentry->d_name;
-       CDEBUG(D_CACHE, "releasing pcc file \"%.*s\"\n", dname->len,
-              dname->name);
+       CDEBUG(D_CACHE, "releasing pcc file \"%pd\"\n", path->dentry);
        pcc_inode_put(pcci);
        fput(pccf->pccf_file);
        pccf->pccf_file = NULL;
@@ -537,13 +1518,7 @@ out:
        RETURN_EXIT;
 }
 
-static inline void pcc_layout_gen_set(struct pcc_inode *pcci,
-                                     __u32 gen)
-{
-       pcci->pcci_layout_gen = gen;
-}
-
-static void pcc_io_init(struct inode *inode, bool *cached)
+static void pcc_io_init(struct inode *inode, enum pcc_io_type iot, bool *cached)
 {
        struct pcc_inode *pcci;
 
@@ -555,6 +1530,14 @@ static void pcc_io_init(struct inode *inode, bool *cached)
                *cached = true;
        } else {
                *cached = false;
+               if (pcc_may_auto_attach(inode, iot)) {
+                       (void) pcc_try_auto_attach(inode, cached, iot);
+                       if (*cached) {
+                               pcci = ll_i2pcci(inode);
+                               LASSERT(atomic_read(&pcci->pcci_refcount) > 0);
+                               atomic_inc(&pcci->pcci_active_ios);
+                       }
+               }
        }
        pcc_inode_unlock(inode);
 }
@@ -608,7 +1591,7 @@ ssize_t pcc_file_read_iter(struct kiocb *iocb,
                           struct iov_iter *iter, bool *cached)
 {
        struct file *file = iocb->ki_filp;
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct pcc_file *pccf = &fd->fd_pcc_file;
        struct inode *inode = file_inode(file);
        ssize_t result;
@@ -620,7 +1603,7 @@ ssize_t pcc_file_read_iter(struct kiocb *iocb,
                RETURN(0);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_READ, cached);
        if (!*cached)
                RETURN(0);
 
@@ -675,7 +1658,7 @@ ssize_t pcc_file_write_iter(struct kiocb *iocb,
                            struct iov_iter *iter, bool *cached)
 {
        struct file *file = iocb->ki_filp;
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct pcc_file *pccf = &fd->fd_pcc_file;
        struct inode *inode = file_inode(file);
        ssize_t result;
@@ -692,7 +1675,7 @@ ssize_t pcc_file_write_iter(struct kiocb *iocb,
                RETURN(-EAGAIN);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_WRITE, cached);
        if (!*cached)
                RETURN(0);
 
@@ -716,6 +1699,7 @@ int pcc_inode_setattr(struct inode *inode, struct iattr *attr,
                      bool *cached)
 {
        int rc;
+       const struct cred *old_cred;
        struct iattr attr2 = *attr;
        struct dentry *pcc_dentry;
        struct pcc_inode *pcci;
@@ -727,26 +1711,30 @@ int pcc_inode_setattr(struct inode *inode, struct iattr *attr,
                RETURN(0);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_SETATTR, cached);
        if (!*cached)
                RETURN(0);
 
        attr2.ia_valid = attr->ia_valid & (ATTR_SIZE | ATTR_ATIME |
                         ATTR_ATIME_SET | ATTR_MTIME | ATTR_MTIME_SET |
-                        ATTR_CTIME);
+                        ATTR_CTIME | ATTR_UID | ATTR_GID);
        pcci = ll_i2pcci(inode);
        pcc_dentry = pcci->pcci_path.dentry;
        inode_lock(pcc_dentry->d_inode);
+       old_cred = override_creds(pcc_super_cred(inode->i_sb));
        rc = pcc_dentry->d_inode->i_op->setattr(pcc_dentry, &attr2);
+       revert_creds(old_cred);
        inode_unlock(pcc_dentry->d_inode);
 
        pcc_io_fini(inode);
        RETURN(rc);
 }
 
-int pcc_inode_getattr(struct inode *inode, bool *cached)
+int pcc_inode_getattr(struct inode *inode, u32 request_mask,
+                     unsigned int flags, bool *cached)
 {
        struct ll_inode_info *lli = ll_i2info(inode);
+       const struct cred *old_cred;
        struct kstat stat;
        s64 atime;
        s64 mtime;
@@ -760,20 +1748,22 @@ int pcc_inode_getattr(struct inode *inode, bool *cached)
                RETURN(0);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_GETATTR, cached);
        if (!*cached)
                RETURN(0);
 
-       rc = ll_vfs_getattr(&ll_i2pcci(inode)->pcci_path, &stat);
+       old_cred = override_creds(pcc_super_cred(inode->i_sb));
+       rc = ll_vfs_getattr(&ll_i2pcci(inode)->pcci_path, &stat, request_mask,
+                           flags);
+       revert_creds(old_cred);
        if (rc)
                GOTO(out, rc);
 
        ll_inode_size_lock(inode);
-       if (inode->i_atime.tv_sec < lli->lli_atime ||
-           lli->lli_update_atime) {
+       if (ll_file_test_and_clear_flag(lli, LLIF_UPDATE_ATIME) ||
+           inode->i_atime.tv_sec < lli->lli_atime)
                inode->i_atime.tv_sec = lli->lli_atime;
-               lli->lli_update_atime = 0;
-       }
+
        inode->i_mtime.tv_sec = lli->lli_mtime;
        inode->i_ctime.tv_sec = lli->lli_ctime;
 
@@ -803,42 +1793,40 @@ out:
        RETURN(rc);
 }
 
+#ifdef HAVE_DEFAULT_FILE_SPLICE_READ_EXPORT
 ssize_t pcc_file_splice_read(struct file *in_file, loff_t *ppos,
                             struct pipe_inode_info *pipe,
-                            size_t count, unsigned int flags,
-                            bool *cached)
+                            size_t count, unsigned int flags)
 {
        struct inode *inode = file_inode(in_file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(in_file);
+       struct ll_file_data *fd = in_file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
+       bool cached = false;
        ssize_t result;
 
        ENTRY;
 
-       *cached = false;
        if (!pcc_file)
-               RETURN(0);
+               RETURN(default_file_splice_read(in_file, ppos, pipe,
+                                               count, flags));
 
-       if (!file_inode(pcc_file)->i_fop->splice_read)
-               RETURN(-ENOTSUPP);
-
-       pcc_io_init(inode, cached);
-       if (!*cached)
-               RETURN(0);
+       pcc_io_init(inode, PIT_SPLICE_READ, &cached);
+       if (!cached)
+               RETURN(default_file_splice_read(in_file, ppos, pipe,
+                                               count, flags));
 
-       result = file_inode(pcc_file)->i_fop->splice_read(pcc_file,
-                                                         ppos, pipe, count,
-                                                         flags);
+       result = default_file_splice_read(pcc_file, ppos, pipe, count, flags);
 
        pcc_io_fini(inode);
        RETURN(result);
 }
+#endif /* HAVE_DEFAULT_FILE_SPLICE_READ_EXPORT */
 
 int pcc_fsync(struct file *file, loff_t start, loff_t end,
              int datasync, bool *cached)
 {
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        int rc;
 
@@ -849,19 +1837,12 @@ int pcc_fsync(struct file *file, loff_t start, loff_t end,
                RETURN(0);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_FSYNC, cached);
        if (!*cached)
                RETURN(0);
 
-#ifdef HAVE_FILE_FSYNC_4ARGS
        rc = file_inode(pcc_file)->i_fop->fsync(pcc_file,
                                                start, end, datasync);
-#elif defined(HAVE_FILE_FSYNC_2ARGS)
-       rc = file_inode(pcc_file)->i_fop->fsync(pcc_file, datasync);
-#else
-       rc = file_inode(pcc_file)->i_fop->fsync(pcc_file,
-                               file_dentry(dentry), datasync);
-#endif
 
        pcc_io_fini(inode);
        RETURN(rc);
@@ -871,7 +1852,7 @@ int pcc_file_mmap(struct file *file, struct vm_area_struct *vma,
                  bool *cached)
 {
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        struct pcc_inode *pcci;
        int rc = 0;
@@ -906,7 +1887,7 @@ void pcc_vm_open(struct vm_area_struct *vma)
        struct pcc_inode *pcci;
        struct file *file = vma->vm_file;
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
 
@@ -930,7 +1911,7 @@ void pcc_vm_close(struct vm_area_struct *vma)
 {
        struct file *file = vma->vm_file;
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
 
@@ -955,22 +1936,32 @@ int pcc_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
        struct mm_struct *mm = vma->vm_mm;
        struct file *file = vma->vm_file;
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
        int rc;
 
        ENTRY;
 
-       if (!pcc_file || !pcc_vm_ops || !pcc_vm_ops->page_mkwrite) {
+       if (!pcc_file || !pcc_vm_ops) {
                *cached = false;
                RETURN(0);
        }
 
+       if (!pcc_vm_ops->page_mkwrite &&
+           page->mapping == pcc_file->f_mapping) {
+               CDEBUG(D_MMAP,
+                      "%s: PCC backend fs not support ->page_mkwrite()\n",
+                      ll_i2sbi(inode)->ll_fsname);
+               pcc_ioctl_detach(inode, PCC_DETACH_OPT_UNCACHE);
+               up_read(&mm->mmap_sem);
+               *cached = true;
+               RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
+       }
        /* Pause to allow for a race with concurrent detach */
        OBD_FAIL_TIMEOUT(OBD_FAIL_LLITE_PCC_MKWRITE_PAUSE, cfs_fail_val);
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_PAGE_MKWRITE, cached);
        if (!*cached) {
                /* This happens when the file is detached from PCC after got
                 * the fault page via ->fault() on the inode of the PCC copy.
@@ -988,7 +1979,7 @@ int pcc_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
                 * VM_FAULT_NOPAGE | VM_FAULT_RETRY to the caller
                 * __do_page_fault and retry the memory fault handling.
                 */
-               if (page->mapping == file_inode(pcc_file)->i_mapping) {
+               if (page->mapping == pcc_file->f_mapping) {
                        *cached = true;
                        up_read(&mm->mmap_sem);
                        RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
@@ -1003,7 +1994,7 @@ int pcc_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
         */
        if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_PCC_DETACH_MKWRITE)) {
                pcc_io_fini(inode);
-               pcc_ioctl_detach(inode);
+               pcc_ioctl_detach(inode, PCC_DETACH_OPT_UNCACHE);
                up_read(&mm->mmap_sem);
                RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
        }
@@ -1025,7 +2016,7 @@ int pcc_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 {
        struct file *file = vma->vm_file;
        struct inode *inode = file_inode(file);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct file *pcc_file = fd->fd_pcc_file.pccf_file;
        struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
        int rc;
@@ -1037,7 +2028,7 @@ int pcc_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
                RETURN(0);
        }
 
-       pcc_io_init(inode, cached);
+       pcc_io_init(inode, PIT_FAULT, cached);
        if (!*cached)
                RETURN(0);
 
@@ -1053,29 +2044,25 @@ int pcc_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
        RETURN(rc);
 }
 
-static void pcc_layout_wait(struct pcc_inode *pcci)
-{
-       struct l_wait_info lwi = { 0 };
-
-       while (atomic_read(&pcci->pcci_active_ios) > 0) {
-               CDEBUG(D_CACHE, "Waiting for IO completion: %d\n",
-                      atomic_read(&pcci->pcci_active_ios));
-               l_wait_event(pcci->pcci_waitq,
-                            atomic_read(&pcci->pcci_active_ios) == 0, &lwi);
-       }
-}
-
 static void __pcc_layout_invalidate(struct pcc_inode *pcci)
 {
        pcci->pcci_type = LU_PCC_NONE;
        pcc_layout_gen_set(pcci, CL_LAYOUT_GEN_NONE);
-       pcc_layout_wait(pcci);
+       if (atomic_read(&pcci->pcci_active_ios) == 0)
+               return;
+
+       CDEBUG(D_CACHE, "Waiting for IO completion: %d\n",
+                      atomic_read(&pcci->pcci_active_ios));
+       wait_event_idle(pcci->pcci_waitq,
+                       atomic_read(&pcci->pcci_active_ios) == 0);
 }
 
 void pcc_layout_invalidate(struct inode *inode)
 {
        struct pcc_inode *pcci;
 
+       ENTRY;
+
        pcc_inode_lock(inode);
        pcci = ll_i2pcci(inode);
        if (pcci && pcc_inode_has_layout(pcci)) {
@@ -1088,17 +2075,18 @@ void pcc_layout_invalidate(struct inode *inode)
                pcc_inode_put(pcci);
        }
        pcc_inode_unlock(inode);
+
+       EXIT;
 }
 
-static int pcc_inode_remove(struct pcc_inode *pcci)
+static int pcc_inode_remove(struct inode *inode, struct dentry *pcc_dentry)
 {
-       struct dentry *dentry;
        int rc;
 
-       dentry = pcci->pcci_path.dentry;
-       rc = ll_vfs_unlink(dentry->d_parent->d_inode, dentry);
+       rc = ll_vfs_unlink(pcc_dentry->d_parent->d_inode, pcc_dentry);
        if (rc)
-               CWARN("failed to unlink cached file, rc = %d\n", rc);
+               CWARN("%s: failed to unlink PCC file %pd, rc = %d\n",
+                     ll_i2sbi(inode)->ll_fsname, pcc_dentry, rc);
 
        return rc;
 }
@@ -1175,7 +2163,7 @@ pcc_create(struct dentry *base, const char *name, umode_t mode)
        if (d_is_positive(dentry))
                goto out;
 
-       rc = vfs_create(dir, dentry, mode, LL_VFS_CREATE_FALSE);
+       rc = vfs_create(dir, dentry, mode, false);
        if (rc) {
                dput(dentry);
                dentry = ERR_PTR(rc);
@@ -1186,20 +2174,6 @@ out:
        return dentry;
 }
 
-/* Must be called with pcci->pcci_lock held */
-static void pcc_inode_attach_init(struct pcc_dataset *dataset,
-                                 struct pcc_inode *pcci,
-                                 struct dentry *dentry,
-                                 enum lu_pcc_type type)
-{
-       pcci->pcci_path.mnt = mntget(dataset->pccd_path.mnt);
-       pcci->pcci_path.dentry = dentry;
-       LASSERT(atomic_read(&pcci->pcci_refcount) == 0);
-       atomic_set(&pcci->pcci_refcount, 1);
-       pcci->pcci_type = type;
-       pcci->pcci_attr_valid = false;
-}
-
 static int __pcc_inode_create(struct pcc_dataset *dataset,
                              struct lu_fid *fid,
                              struct dentry **dentry)
@@ -1215,14 +2189,14 @@ static int __pcc_inode_create(struct pcc_dataset *dataset,
 
        pcc_fid2dataset_path(path, MAX_PCC_DATABASE_PATH, fid);
 
-       base = pcc_mkdir_p(dataset->pccd_path.dentry, path, 0700);
+       base = pcc_mkdir_p(dataset->pccd_path.dentry, path, 0);
        if (IS_ERR(base)) {
                rc = PTR_ERR(base);
                GOTO(out, rc);
        }
 
        snprintf(path, MAX_PCC_DATABASE_PATH, DFID_NOBRACE, PFID(fid));
-       child = pcc_create(base, path, 0600);
+       child = pcc_create(base, path, 0);
        if (IS_ERR(child)) {
                rc = PTR_ERR(child);
                GOTO(out_base, rc);
@@ -1236,53 +2210,133 @@ out:
        return rc;
 }
 
-int pcc_inode_create(struct pcc_dataset *dataset, struct lu_fid *fid,
-                    struct dentry **pcc_dentry)
+/*
+ * Reset uid, gid or size for the PCC copy masked by @valid.
+ * TODO: Set the project ID for PCC copy.
+ */
+int pcc_inode_reset_iattr(struct dentry *dentry, unsigned int valid,
+                         kuid_t uid, kgid_t gid, loff_t size)
+{
+       struct inode *inode = dentry->d_inode;
+       struct iattr attr;
+       int rc;
+
+       ENTRY;
+
+       attr.ia_valid = valid;
+       attr.ia_uid = uid;
+       attr.ia_gid = gid;
+       attr.ia_size = size;
+
+       inode_lock(inode);
+       rc = notify_change(dentry, &attr, NULL);
+       inode_unlock(inode);
+
+       RETURN(rc);
+}
+
+int pcc_inode_create(struct super_block *sb, struct pcc_dataset *dataset,
+                    struct lu_fid *fid, struct dentry **pcc_dentry)
 {
-       return __pcc_inode_create(dataset, fid, pcc_dentry);
+       const struct cred *old_cred;
+       int rc;
+
+       old_cred = override_creds(pcc_super_cred(sb));
+       rc = __pcc_inode_create(dataset, fid, pcc_dentry);
+       revert_creds(old_cred);
+       return rc;
 }
 
-int pcc_inode_create_fini(struct pcc_dataset *dataset, struct inode *inode,
-                         struct dentry *pcc_dentry)
+int pcc_inode_create_fini(struct inode *inode, struct pcc_create_attach *pca)
 {
+       struct dentry *pcc_dentry = pca->pca_dentry;
+       struct pcc_super *super = ll_i2pccs(inode);
+       const struct cred *old_cred;
        struct pcc_inode *pcci;
-       int rc = 0;
+       int rc;
 
        ENTRY;
 
+       if (!pca->pca_dataset)
+               RETURN(0);
+
+       if (!inode)
+               GOTO(out_dataset_put, rc = 0);
+
+       LASSERT(pcc_dentry);
+
+       old_cred = override_creds(super->pccs_cred);
        pcc_inode_lock(inode);
        LASSERT(ll_i2pcci(inode) == NULL);
        OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
        if (pcci == NULL)
-               GOTO(out_unlock, rc = -ENOMEM);
+               GOTO(out_put, rc = -ENOMEM);
 
-       pcc_inode_init(pcci, ll_i2info(inode));
-       pcc_inode_attach_init(dataset, pcci, pcc_dentry, LU_PCC_READWRITE);
-       /* Set the layout generation of newly created file with 0 */
-       pcc_layout_gen_set(pcci, 0);
+       rc = pcc_inode_reset_iattr(pcc_dentry, ATTR_UID | ATTR_GID,
+                                  old_cred->suid, old_cred->sgid, 0);
+       if (rc)
+               GOTO(out_put, rc);
 
-out_unlock:
+       pcc_inode_attach_set(super, pca->pca_dataset, ll_i2info(inode),
+                            pcci, pcc_dentry, LU_PCC_READWRITE);
+
+       rc = pcc_layout_xattr_set(pcci, 0);
        if (rc) {
-               int rc2;
+               (void) pcc_inode_remove(inode, pcci->pcci_path.dentry);
+               pcc_inode_put(pcci);
+               GOTO(out_unlock, rc);
+       }
 
-               rc2 = ll_vfs_unlink(pcc_dentry->d_parent->d_inode, pcc_dentry);
-               if (rc2)
-                       CWARN("failed to unlink PCC file, rc = %d\n", rc2);
+       /* Set the layout generation of newly created file with 0 */
+       pcc_layout_gen_set(pcci, 0);
 
+out_put:
+       if (rc) {
+               (void) pcc_inode_remove(inode, pcc_dentry);
                dput(pcc_dentry);
-       }
 
+               if (pcci)
+                       OBD_SLAB_FREE_PTR(pcci, pcc_inode_slab);
+       }
+out_unlock:
        pcc_inode_unlock(inode);
+       revert_creds(old_cred);
+out_dataset_put:
+       pcc_dataset_put(pca->pca_dataset);
        RETURN(rc);
 }
 
+void pcc_create_attach_cleanup(struct super_block *sb,
+                              struct pcc_create_attach *pca)
+{
+       if (!pca->pca_dataset)
+               return;
+
+       if (pca->pca_dentry) {
+               const struct cred *old_cred;
+               int rc;
+
+               old_cred = override_creds(pcc_super_cred(sb));
+               rc = ll_vfs_unlink(pca->pca_dentry->d_parent->d_inode,
+                                  pca->pca_dentry);
+               if (rc)
+                       CWARN("%s: failed to unlink PCC file %pd: rc = %d\n",
+                             ll_s2sbi(sb)->ll_fsname, pca->pca_dentry, rc);
+               /* ignore the unlink failure */
+               revert_creds(old_cred);
+               dput(pca->pca_dentry);
+       }
+
+       pcc_dataset_put(pca->pca_dataset);
+}
+
 static int pcc_filp_write(struct file *filp, const void *buf, ssize_t count,
                          loff_t *offset)
 {
        while (count > 0) {
                ssize_t size;
 
-               size = vfs_write(filp, (const void __user *)buf, count, offset);
+               size = cfs_kernel_write(filp, buf, count, offset);
                if (size < 0)
                        return size;
                count -= size;
@@ -1291,11 +2345,10 @@ static int pcc_filp_write(struct file *filp, const void *buf, ssize_t count,
        return 0;
 }
 
-static int pcc_copy_data(struct file *src, struct file *dst)
+static ssize_t pcc_copy_data(struct file *src, struct file *dst)
 {
-       int rc = 0;
+       ssize_t rc = 0;
        ssize_t rc2;
-       mm_segment_t oldfs;
        loff_t pos, offset = 0;
        size_t buf_len = 1048576;
        void *buf;
@@ -1306,25 +2359,26 @@ static int pcc_copy_data(struct file *src, struct file *dst)
        if (buf == NULL)
                RETURN(-ENOMEM);
 
-       oldfs = get_fs();
-       set_fs(KERNEL_DS);
        while (1) {
+               if (signal_pending(current))
+                       GOTO(out_free, rc = -EINTR);
+
                pos = offset;
-               rc2 = vfs_read(src, (void __user *)buf, buf_len, &pos);
+               rc2 = cfs_kernel_read(src, buf, buf_len, &pos);
                if (rc2 < 0)
-                       GOTO(out_fs, rc = rc2);
+                       GOTO(out_free, rc = rc2);
                else if (rc2 == 0)
                        break;
 
                pos = offset;
                rc = pcc_filp_write(dst, buf, rc2, &pos);
                if (rc < 0)
-                       GOTO(out_fs, rc);
+                       GOTO(out_free, rc);
                offset += rc2;
        }
 
-out_fs:
-       set_fs(oldfs);
+       rc = offset;
+out_free:
        OBD_FREE_LARGE(buf, buf_len);
        RETURN(rc);
 }
@@ -1356,10 +2410,13 @@ int pcc_readwrite_attach(struct file *file, struct inode *inode,
 {
        struct pcc_dataset *dataset;
        struct ll_inode_info *lli = ll_i2info(inode);
+       struct pcc_super *super = ll_i2pccs(inode);
        struct pcc_inode *pcci;
+       const struct cred *old_cred;
        struct dentry *dentry;
        struct file *pcc_filp;
        struct path path;
+       ssize_t ret;
        int rc;
 
        ENTRY;
@@ -1368,31 +2425,40 @@ int pcc_readwrite_attach(struct file *file, struct inode *inode,
        if (rc)
                RETURN(rc);
 
-       dataset = pcc_dataset_get(&ll_i2sbi(inode)->ll_pcc_super, 0,
-                                 archive_id);
+       dataset = pcc_dataset_get(&ll_i2sbi(inode)->ll_pcc_super,
+                                 LU_PCC_READWRITE, archive_id);
        if (dataset == NULL)
                RETURN(-ENOENT);
 
+       old_cred = override_creds(super->pccs_cred);
        rc = __pcc_inode_create(dataset, &lli->lli_fid, &dentry);
        if (rc)
                GOTO(out_dataset_put, rc);
 
        path.mnt = dataset->pccd_path.mnt;
        path.dentry = dentry;
-#ifdef HAVE_DENTRY_OPEN_USE_PATH
-       pcc_filp = dentry_open(&path, O_TRUNC | O_WRONLY | O_LARGEFILE,
-                              current_cred());
-#else
-       pcc_filp = dentry_open(path.dentry, path.mnt,
-                              O_TRUNC | O_WRONLY | O_LARGEFILE,
-                              current_cred());
-#endif
+       pcc_filp = dentry_open(&path, O_WRONLY | O_LARGEFILE, current_cred());
        if (IS_ERR_OR_NULL(pcc_filp)) {
                rc = pcc_filp == NULL ? -EINVAL : PTR_ERR(pcc_filp);
                GOTO(out_dentry, rc);
        }
 
-       rc = pcc_copy_data(file, pcc_filp);
+       rc = pcc_inode_reset_iattr(dentry, ATTR_UID | ATTR_GID,
+                                  old_cred->uid, old_cred->gid, 0);
+       if (rc)
+               GOTO(out_fput, rc);
+
+       ret = pcc_copy_data(file, pcc_filp);
+       if (ret < 0)
+               GOTO(out_fput, rc = ret);
+
+       /*
+        * It must to truncate the PCC copy to the same size of the Lustre
+        * copy after copy data. Otherwise, it may get wrong file size after
+        * re-attach a file. See LU-13023 for details.
+        */
+       rc = pcc_inode_reset_iattr(dentry, ATTR_SIZE, KUIDT_INIT(0),
+                                  KGIDT_INIT(0), ret);
        if (rc)
                GOTO(out_fput, rc);
 
@@ -1406,24 +2472,21 @@ int pcc_readwrite_attach(struct file *file, struct inode *inode,
        if (pcci == NULL)
                GOTO(out_unlock, rc = -ENOMEM);
 
-       pcc_inode_init(pcci, lli);
-       pcc_inode_attach_init(dataset, pcci, dentry, LU_PCC_READWRITE);
+       pcc_inode_attach_set(super, dataset, lli, pcci,
+                            dentry, LU_PCC_READWRITE);
 out_unlock:
        pcc_inode_unlock(inode);
 out_fput:
        fput(pcc_filp);
 out_dentry:
        if (rc) {
-               int rc2;
-
-               rc2 = ll_vfs_unlink(dentry->d_parent->d_inode, dentry);
-               if (rc2)
-                       CWARN("failed to unlink PCC file, rc = %d\n", rc2);
-
+               (void) pcc_inode_remove(inode, dentry);
                dput(dentry);
        }
 out_dataset_put:
        pcc_dataset_put(dataset);
+       revert_creds(old_cred);
+
        RETURN(rc);
 }
 
@@ -1432,15 +2495,16 @@ int pcc_readwrite_attach_fini(struct file *file, struct inode *inode,
                              bool attached)
 {
        struct ll_inode_info *lli = ll_i2info(inode);
+       const struct cred *old_cred;
        struct pcc_inode *pcci;
        __u32 gen2;
 
        ENTRY;
 
+       old_cred = override_creds(pcc_super_cred(inode->i_sb));
        pcc_inode_lock(inode);
        pcci = ll_i2pcci(inode);
-       lli->lli_pcc_state &= ~PCC_STATE_FL_ATTACHING;
-       if ((rc || lease_broken)) {
+       if (rc || lease_broken) {
                if (attached && pcci)
                        pcc_inode_put(pcci);
 
@@ -1452,6 +2516,11 @@ int pcc_readwrite_attach_fini(struct file *file, struct inode *inode,
                GOTO(out_unlock, rc = -ESTALE);
 
        LASSERT(attached);
+       rc = pcc_layout_xattr_set(pcci, gen);
+       if (rc)
+               GOTO(out_put, rc);
+
+       LASSERT(lli->lli_pcc_state & PCC_STATE_FL_ATTACHING);
        rc = ll_layout_refresh(inode, &gen2);
        if (!rc) {
                if (gen2 == gen) {
@@ -1466,18 +2535,63 @@ int pcc_readwrite_attach_fini(struct file *file, struct inode *inode,
 
 out_put:
        if (rc) {
-               pcc_inode_remove(pcci);
+               (void) pcc_inode_remove(inode, pcci->pcci_path.dentry);
                pcc_inode_put(pcci);
        }
 out_unlock:
+       lli->lli_pcc_state &= ~PCC_STATE_FL_ATTACHING;
        pcc_inode_unlock(inode);
+       revert_creds(old_cred);
+       RETURN(rc);
+}
+
+static int pcc_hsm_remove(struct inode *inode)
+{
+       struct hsm_user_request *hur;
+       __u32 gen;
+       int len;
+       int rc;
+
+       ENTRY;
+
+       rc = ll_layout_restore(inode, 0, OBD_OBJECT_EOF);
+       if (rc) {
+               CDEBUG(D_CACHE, DFID" RESTORE failure: %d\n",
+                      PFID(&ll_i2info(inode)->lli_fid), rc);
+               RETURN(rc);
+       }
+
+       ll_layout_refresh(inode, &gen);
+
+       len = sizeof(struct hsm_user_request) +
+             sizeof(struct hsm_user_item);
+       OBD_ALLOC(hur, len);
+       if (hur == NULL)
+               RETURN(-ENOMEM);
+
+       hur->hur_request.hr_action = HUA_REMOVE;
+       hur->hur_request.hr_archive_id = 0;
+       hur->hur_request.hr_flags = 0;
+       memcpy(&hur->hur_user_item[0].hui_fid, &ll_i2info(inode)->lli_fid,
+              sizeof(hur->hur_user_item[0].hui_fid));
+       hur->hur_user_item[0].hui_extent.offset = 0;
+       hur->hur_user_item[0].hui_extent.length = OBD_OBJECT_EOF;
+       hur->hur_request.hr_itemcount = 1;
+       rc = obd_iocontrol(LL_IOC_HSM_REQUEST, ll_i2sbi(inode)->ll_md_exp,
+                          len, hur, NULL);
+       if (rc)
+               CDEBUG(D_CACHE, DFID" HSM REMOVE failure: %d\n",
+                      PFID(&ll_i2info(inode)->lli_fid), rc);
+
+       OBD_FREE(hur, len);
        RETURN(rc);
 }
 
-int pcc_ioctl_detach(struct inode *inode)
+int pcc_ioctl_detach(struct inode *inode, __u32 opt)
 {
        struct ll_inode_info *lli = ll_i2info(inode);
        struct pcc_inode *pcci;
+       bool hsm_remove = false;
        int rc = 0;
 
        ENTRY;
@@ -1488,11 +2602,33 @@ int pcc_ioctl_detach(struct inode *inode)
            !pcc_inode_has_layout(pcci))
                GOTO(out_unlock, rc = 0);
 
-       __pcc_layout_invalidate(pcci);
-       pcc_inode_put(pcci);
+       LASSERT(atomic_read(&pcci->pcci_refcount) > 0);
+
+       if (pcci->pcci_type == LU_PCC_READWRITE) {
+               if (opt == PCC_DETACH_OPT_UNCACHE) {
+                       hsm_remove = true;
+                       /*
+                        * The file will be removed from PCC, set the flags
+                        * with PCC_DATASET_NONE even the later removal of the
+                        * PCC copy fails.
+                        */
+                       lli->lli_pcc_dsflags = PCC_DATASET_NONE;
+               }
+
+               __pcc_layout_invalidate(pcci);
+               pcc_inode_put(pcci);
+       }
 
 out_unlock:
        pcc_inode_unlock(inode);
+       if (hsm_remove) {
+               const struct cred *old_cred;
+
+               old_cred = override_creds(pcc_super_cred(inode->i_sb));
+               rc = pcc_hsm_remove(inode);
+               revert_creds(old_cred);
+       }
+
        RETURN(rc);
 }
 
@@ -1504,7 +2640,7 @@ int pcc_ioctl_state(struct file *file, struct inode *inode,
        char *buf;
        char *path;
        int buf_len = sizeof(state->pccs_path);
-       struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+       struct ll_file_data *fd = file->private_data;
        struct pcc_file *pccf = &fd->fd_pcc_file;
        struct pcc_inode *pcci;
 
@@ -1538,13 +2674,9 @@ int pcc_ioctl_state(struct file *file, struct inode *inode,
        state->pccs_type = pcci->pcci_type;
        state->pccs_open_count = count;
        state->pccs_flags = ll_i2info(inode)->lli_pcc_state;
-#ifdef HAVE_DENTRY_PATH_RAW
        path = dentry_path_raw(pcci->pcci_path.dentry, buf, buf_len);
        if (IS_ERR(path))
                GOTO(out_unlock, rc = PTR_ERR(path));
-#else
-       path = "UNKNOWN";
-#endif
 
        if (strlcpy(state->pccs_path, path, buf_len) >= buf_len)
                GOTO(out_unlock, rc = -ENAMETOOLONG);