LU-12682 llite: fake symlink type of foreign file/dir

[fs/lustre-release.git] / lustre / llite / llite_lib.c

diff --git a/lustre/llite/llite_lib.c b/lustre/llite/llite_lib.c
index bf5a09a..1f094ce 100644 (file)
--- a/lustre/llite/llite_lib.c
+++ b/lustre/llite/llite_lib.c
@@ -129,6 +129,25 @@ static struct ll_sb_info *ll_init_sbi(void)
        if (sbi->ll_cache == NULL)
                GOTO(out_destroy_ra, rc = -ENOMEM);
 
+       /* initialize foreign symlink prefix path */
+       OBD_ALLOC(sbi->ll_foreign_symlink_prefix, sizeof("/mnt/"));
+       if (sbi->ll_foreign_symlink_prefix == NULL)
+               GOTO(out_destroy_ra, rc = -ENOMEM);
+       memcpy(sbi->ll_foreign_symlink_prefix, "/mnt/", sizeof("/mnt/"));
+       sbi->ll_foreign_symlink_prefix_size = sizeof("/mnt/");
+
+       /* initialize foreign symlink upcall path, none by default */
+       OBD_ALLOC(sbi->ll_foreign_symlink_upcall, sizeof("none"));
+       if (sbi->ll_foreign_symlink_upcall == NULL)
+               GOTO(out_destroy_ra, rc = -ENOMEM);
+       memcpy(sbi->ll_foreign_symlink_upcall, "none", sizeof("none"));
+       sbi->ll_foreign_symlink_upcall_items = NULL;
+       sbi->ll_foreign_symlink_upcall_nb_items = 0;
+       init_rwsem(&sbi->ll_foreign_symlink_sem);
+       /* foreign symlink support (LL_SBI_FOREIGN_SYMLINK in ll_flags)
+        * not enabled by default
+        */
+
        sbi->ll_ra_info.ra_max_pages =
                min(pages / 32, SBI_DEFAULT_READ_AHEAD_MAX);
        sbi->ll_ra_info.ra_max_pages_per_file =
@@ -183,6 +202,12 @@ static struct ll_sb_info *ll_init_sbi(void)
        sbi->ll_heat_period_second = SBI_DEFAULT_HEAT_PERIOD_SECOND;
        RETURN(sbi);
 out_destroy_ra:
+       if (sbi->ll_foreign_symlink_prefix)
+               OBD_FREE(sbi->ll_foreign_symlink_prefix, sizeof("/mnt/"));
+       if (sbi->ll_cache) {
+               cl_cache_decref(sbi->ll_cache);
+               sbi->ll_cache = NULL;
+       }
        destroy_workqueue(sbi->ll_ra_info.ll_readahead_wq);
 out_pcc:
        pcc_super_fini(&sbi->ll_pcc_super);
@@ -205,6 +230,32 @@ static void ll_free_sbi(struct super_block *sb)
                        cl_cache_decref(sbi->ll_cache);
                        sbi->ll_cache = NULL;
                }
+               if (sbi->ll_foreign_symlink_prefix) {
+                       OBD_FREE(sbi->ll_foreign_symlink_prefix,
+                                sbi->ll_foreign_symlink_prefix_size);
+                       sbi->ll_foreign_symlink_prefix = NULL;
+               }
+               if (sbi->ll_foreign_symlink_upcall) {
+                       OBD_FREE(sbi->ll_foreign_symlink_upcall,
+                                strlen(sbi->ll_foreign_symlink_upcall) +
+                                      1);
+                       sbi->ll_foreign_symlink_upcall = NULL;
+               }
+               if (sbi->ll_foreign_symlink_upcall_items) {
+                       int i;
+                       int nb_items = sbi->ll_foreign_symlink_upcall_nb_items;
+                       struct ll_foreign_symlink_upcall_item *items =
+                               sbi->ll_foreign_symlink_upcall_items;
+
+                       for (i = 0 ; i < nb_items; i++)
+                               if (items[i].type == STRING_TYPE)
+                                       OBD_FREE(items[i].string,
+                                                      items[i].size);
+
+                       OBD_FREE_LARGE(items, nb_items *
+                               sizeof(struct ll_foreign_symlink_upcall_item));
+                       sbi->ll_foreign_symlink_upcall_items = NULL;
+               }
                pcc_super_fini(&sbi->ll_pcc_super);
                OBD_FREE(sbi, sizeof(*sbi));
        }
@@ -988,6 +1039,58 @@ static int ll_options(char *options, struct ll_sb_info *sbi)
 #endif
                        goto next;
                }
+               tmp = ll_set_opt("foreign_symlink", s1, LL_SBI_FOREIGN_SYMLINK);
+               if (tmp) {
+                       int prefix_pos = sizeof("foreign_symlink=") - 1;
+                       int equal_pos = sizeof("foreign_symlink=") - 2;
+
+                       /* non-default prefix provided ? */
+                       if (strlen(s1) >= sizeof("foreign_symlink=") &&
+                           *(s1 + equal_pos) == '=') {
+                               char *old = sbi->ll_foreign_symlink_prefix;
+                               size_t old_len =
+                                       sbi->ll_foreign_symlink_prefix_size;
+
+                               /* path must be absolute */
+                               if (*(s1 + sizeof("foreign_symlink=")
+                                     - 1) != '/') {
+                                       LCONSOLE_ERROR_MSG(0x152,
+                                               "foreign prefix '%s' must be an absolute path\n",
+                                               s1 + prefix_pos);
+                                       RETURN(-EINVAL);
+                               }
+                               /* last option ? */
+                               s2 = strchrnul(s1 + prefix_pos, ',');
+
+                               if (sbi->ll_foreign_symlink_prefix) {
+                                       sbi->ll_foreign_symlink_prefix = NULL;
+                                       sbi->ll_foreign_symlink_prefix_size = 0;
+                               }
+                               /* alloc for path length and '\0' */
+                               OBD_ALLOC(sbi->ll_foreign_symlink_prefix,
+                                               s2 - (s1 + prefix_pos) + 1);
+                               if (!sbi->ll_foreign_symlink_prefix) {
+                                       /* restore previous */
+                                       sbi->ll_foreign_symlink_prefix = old;
+                                       sbi->ll_foreign_symlink_prefix_size =
+                                               old_len;
+                                       RETURN(-ENOMEM);
+                               }
+                               if (old)
+                                       OBD_FREE(old, old_len);
+                               strncpy(sbi->ll_foreign_symlink_prefix,
+                                       s1 + prefix_pos,
+                                       s2 - (s1 + prefix_pos));
+                               sbi->ll_foreign_symlink_prefix_size =
+                                       s2 - (s1 + prefix_pos) + 1;
+                       } else {
+                               LCONSOLE_ERROR_MSG(0x152,
+                                                  "invalid %s option\n", s1);
+                       }
+                       /* enable foreign symlink support */
+                       *flags |= tmp;
+                       goto next;
+               }
                 LCONSOLE_ERROR_MSG(0x152, "Unknown option '%s', won't mount.\n",
                                    s1);
                 RETURN(-EINVAL);
@@ -2870,6 +2973,13 @@ int ll_prep_inode(struct inode **inode, struct ptlrpc_request *req,
        if (default_lmv_deleted)
                ll_update_default_lsm_md(*inode, &md);
 
+       /* we may want to apply some policy for foreign file/dir */
+       if (ll_sbi_has_foreign_symlink(sbi)) {
+               rc = ll_manage_foreign(*inode, &md);
+               if (rc < 0)
+                       GOTO(out, rc);
+       }
+
        GOTO(out, rc = 0);
 
 out:
@@ -3074,6 +3184,11 @@ int ll_show_options(struct seq_file *seq, struct dentry *dentry)
        else
                seq_puts(seq, ",noencrypt");
 
+       if (sbi->ll_flags & LL_SBI_FOREIGN_SYMLINK) {
+               seq_puts(seq, ",foreign_symlink=");
+               seq_puts(seq, sbi->ll_foreign_symlink_prefix);
+       }
+
        RETURN(0);
 }