[Libguestfs] [PATCH v6 34/41] daemon: Reimplement ‘findfs_uuid’ and ‘findfs_label’ APIs in OCaml.

--- daemon/Makefile.am | 3 +- daemon/findfs.c | 94 ----------------------------------------------- daemon/findfs.ml | 56 ++++++++++++++++++++++++++++ daemon/findfs.mli | 20 ++++++++++ daemon/lvm.c | 31 ++++++++++++++++ daemon/lvm.ml | 3 ++ daemon/lvm.mli | 8 ++++ docs/C_SOURCE_FILES | 1 - generator/actions_core.ml | 2 + 9 files changed, 122 insertions(+), 96 deletions(-) diff --git a/daemon/Makefile.am b/daemon/Makefile.am index a3c486046..15b78d6d8 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -108,7 +108,6 @@ guestfsd_SOURCES = \ ext2.c \ fallocate.c \ file.c \ - findfs.c \ fill.c \ find.c \ format.c \ @@ -265,6 +264,7 @@ SOURCES_MLI = \ devsparts.mli \ file.mli \ filearch.mli \ + findfs.mli \ is.mli \ ldm.mli \ link.mli \ @@ -293,6 +293,7 @@ SOURCES_ML = \ ldm.ml \ link.ml \ lvm.ml \ + findfs.ml \ md.ml \ mount.ml \ parted.ml \ diff --git a/daemon/findfs.c b/daemon/findfs.c deleted file mode 100644 index f44137038..000000000 --- a/daemon/findfs.c +++ /dev/null @@ -1,94 +0,0 @@ -/* libguestfs - the guestfsd daemon - * Copyright (C) 2010 Red Hat Inc. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - */ - -#include <config.h> - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -#include "daemon.h" -#include "actions.h" - -GUESTFSD_EXT_CMD(str_findfs, findfs); - -static char * -findfs (const char *tag, const char *label_or_uuid) -{ - char *out; - CLEANUP_FREE char *err = NULL; - CLEANUP_FREE char *arg = NULL; - int r; - size_t len; - - /* Kill the cache file, forcing blkid to reread values from the - * original filesystems. In blkid there is a '-p' option which is - * supposed to do this, but (a) it doesn't work and (b) that option - * is not supported in RHEL 5. - */ - unlink ("/etc/blkid/blkid.tab"); - unlink ("/run/blkid/blkid.tab"); - - if (asprintf (&arg, "%s=%s", tag, label_or_uuid) == -1) { - reply_with_perror ("asprintf"); - return NULL; - } - - r = command (&out, &err, str_findfs, arg, NULL); - if (r == -1) { - reply_with_error ("%s", err); - free (out); - return NULL; - } - - /* Trim trailing \n if present. */ - len = strlen (out); - if (len > 0 && out[len-1] == '\n') - out[len-1] = '\0'; - - if (STRPREFIX (out, "/dev/mapper/") || STRPREFIX (out, "/dev/dm-")) { - char *canonical; - r = lv_canonical (out, &canonical); - if (r == -1) { - free (out); - return NULL; - } - if (r == 1) { - free (out); - out = canonical; - } - /* Ignore the case where r == 0. /dev/mapper does not correspond - * to an LV, so the best we can do is just return it as-is. - */ - } - - return out; /* caller frees */ -} - -char * -do_findfs_uuid (const char *uuid) -{ - return findfs ("UUID", uuid); -} - -char * -do_findfs_label (const char *label) -{ - return findfs ("LABEL", label); -} diff --git a/daemon/findfs.ml b/daemon/findfs.ml new file mode 100644 index 000000000..8acb72928 --- /dev/null +++ b/daemon/findfs.ml @@ -0,0 +1,56 @@ +(* guestfs-inspection + * Copyright (C) 2009-2017 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +open Printf +open Unix + +open Std_utils + +open Utils + +let rec findfs_uuid uuid = + findfs "UUID" uuid +and findfs_label label = + findfs "LABEL"label + +and findfs tag str = + (* Kill the cache file, forcing blkid to reread values from the + * original filesystems. In blkid there is a '-p' option which is + * supposed to do this, but (a) it doesn't work and (b) that option + * is not supported in RHEL 5. + *) + (try unlink "/etc/blkid/blkid.tab" with Unix_error _ -> ()); + (try unlink "/run/blkid/blkid.tab" with Unix_error _ -> ()); + + let out = command "findfs" [ sprintf "%s=%s" tag str ] in + + (* Trim trailing \n if present. *) + let out = String.trim out in + + if String.is_prefix out "/dev/mapper/" || + String.is_prefix out "/dev/dm-" then ( + match Lvm.lv_canonical out with + | None -> + (* Ignore the case where 'out' doesn't appear to be an LV. + * The best we can do is return the original as-is. + *) + out + | Some out -> out + ) + else + out diff --git a/daemon/findfs.mli b/daemon/findfs.mli new file mode 100644 index 000000000..acef0395c --- /dev/null +++ b/daemon/findfs.mli @@ -0,0 +1,20 @@ +(* guestfs-inspection + * Copyright (C) 2009-2017 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + *) + +val findfs_uuid : string -> string +val findfs_label : string -> string diff --git a/daemon/lvm.c b/daemon/lvm.c index 072bf53b4..268d87416 100644 --- a/daemon/lvm.c +++ b/daemon/lvm.c @@ -27,6 +27,11 @@ #include <sys/stat.h> #include <dirent.h> +#include <caml/alloc.h> +#include <caml/fail.h> +#include <caml/memory.h> +#include <caml/mlvalues.h> + #include "daemon.h" #include "c-ctype.h" #include "actions.h" @@ -969,3 +974,29 @@ do_vgchange_uuid_all (void) return 0; } + +/* Allow lv_canonical to be called from OCaml functions in the daemon. */ +extern value guestfs_int_daemon_lv_canonical (value devicev); + +value +guestfs_int_daemon_lv_canonical (value devicev) +{ + CAMLparam1 (devicev); + CAMLlocal2 (rv, v); + int r; + CLEANUP_FREE char *rdevice = NULL; + + r = lv_canonical (String_val (devicev), &rdevice); + if (r == -1) + caml_failwith ("lv_canonical"); + + if (r == 0) /* Return None. */ + rv = Val_int (0); + else { /* Return Some rdevice. */ + v = caml_copy_string (rdevice); + rv = caml_alloc (1, 0); + caml_modify (&Field (rv, 0), v); + } + + CAMLreturn (rv); +} diff --git a/daemon/lvm.ml b/daemon/lvm.ml index 14f0a8578..8647f3246 100644 --- a/daemon/lvm.ml +++ b/daemon/lvm.ml @@ -25,6 +25,9 @@ open Utils external available : unit -> bool = "guestfs_int_daemon_optgroup_lvm2_available" "noalloc" +external lv_canonical : string -> string option = + "guestfs_int_daemon_lv_canonical" + let lvs_has_S_opt = lazy ( let out = command "lvm" ["lvs"; "--help"] in String.find out "-S" >= 0 diff --git a/daemon/lvm.mli b/daemon/lvm.mli index 1cf61ecfb..f01f1f80c 100644 --- a/daemon/lvm.mli +++ b/daemon/lvm.mli @@ -19,3 +19,11 @@ val available : unit -> bool val lvs : unit -> string list + +val lv_canonical : string -> string option +(** This is a binding for the C lv_canonical function used in a + few cases. On error this raises an exception. There are + two possible non-error cases: + + Some lv = conversion was successful, returning the canonical LV + None = input path was not an LV, it could not be made canonical *) diff --git a/docs/C_SOURCE_FILES b/docs/C_SOURCE_FILES index c01064803..651d294c5 100644 --- a/docs/C_SOURCE_FILES +++ b/docs/C_SOURCE_FILES @@ -103,7 +103,6 @@ daemon/fallocate.c daemon/file.c daemon/fill.c daemon/find.c -daemon/findfs.c daemon/format.c daemon/fs-min-size.c daemon/fsck.c diff --git a/generator/actions_core.ml b/generator/actions_core.ml index b1e2559e0..0a967f76d 100644 --- a/generator/actions_core.ml +++ b/generator/actions_core.ml @@ -5746,6 +5746,7 @@ returns true iff this is the case." }; { defaults with name = "findfs_uuid"; added = (1, 5, 3); style = RString (RDevice, "device"), [String (PlainString, "uuid")], []; + impl = OCaml "Findfs.findfs_uuid"; shortdesc = "find a filesystem by UUID"; longdesc = "\ This command searches the filesystems and returns the one @@ -5757,6 +5758,7 @@ To find the UUID of a filesystem, use C<guestfs_vfs_uuid>." }; { defaults with name = "findfs_label"; added = (1, 5, 3); style = RString (RDevice, "device"), [String (PlainString, "label")], []; + impl = OCaml "Findfs.findfs_label"; shortdesc = "find a filesystem by label"; longdesc = "\ This command searches the filesystems and returns the one -- 2.13.0