[Libguestfs] [PATCH v2 16/23] daemon: Reimplement ‘list_filesystems’ API in the daemon, in OCaml.

Move the list_filesystems API into the daemon, reimplementing it in OCaml. Since this API makes many other API calls, it runs a lot faster in the daemon. --- daemon/Makefile.am | 2 + daemon/ldm.ml | 3 + daemon/ldm.mli | 2 + daemon/listfs.ml | 159 ++++++++++++++++++++++++++++++ daemon/listfs.mli | 19 ++++ daemon/lvm.ml | 3 + daemon/lvm.mli | 2 + docs/C_SOURCE_FILES | 1 - generator/actions_core.ml | 75 +++++++------- generator/proc_nr.ml | 1 + lib/MAX_PROC_NR | 2 +- lib/Makefile.am | 1 - lib/listfs.c | 246 ---------------------------------------------- 13 files changed, 230 insertions(+), 286 deletions(-) diff --git a/daemon/Makefile.am b/daemon/Makefile.am index 94e8e0417..d6a7ae544 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -252,6 +252,7 @@ SOURCES_MLI = \ is.mli \ ldm.mli \ link.mli \ + listfs.mli \ lvm.mli \ md.mli \ mount.mli \ @@ -279,6 +280,7 @@ SOURCES_ML = \ md.ml \ mount.ml \ parted.ml \ + listfs.ml \ realpath.ml \ callbacks.ml \ daemon.ml diff --git a/daemon/ldm.ml b/daemon/ldm.ml index f943e3cfd..dd736cc1f 100644 --- a/daemon/ldm.ml +++ b/daemon/ldm.ml @@ -20,6 +20,9 @@ open Std_utils open Utils +external available : unit -> bool = + "guestfs_int_daemon_optgroup_lvm2_available" "noalloc" + (* All device mapper devices are called /dev/mapper/ldm_vol_* * or /dev/mapper/ldm_part_*. * diff --git a/daemon/ldm.mli b/daemon/ldm.mli index 789abb0b3..e6edfabd8 100644 --- a/daemon/ldm.mli +++ b/daemon/ldm.mli @@ -16,5 +16,7 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *) +val available : unit -> bool + val list_ldm_volumes : unit -> string list val list_ldm_partitions : unit -> string list diff --git a/daemon/listfs.ml b/daemon/listfs.ml new file mode 100644 index 000000000..610a1ea78 --- /dev/null +++ b/daemon/listfs.ml @@ -0,0 +1,159 @@ +(* 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 Std_utils + +let rec list_filesystems () = + let has_lvm2 = Lvm.available () in + let has_ldm = Ldm.available () in + + let devices = Devsparts.list_devices () in + let partitions = Devsparts.list_partitions () in + let mds = Md.list_md_devices () in + + (* Look to see if any devices directly contain filesystems + * (RHBZ#590167). However vfs-type will fail to tell us anything + * useful about devices which just contain partitions, so we also + * get the list of partitions and exclude the corresponding devices + * by using part-to-dev. + *) + let devices_containing_partitions = List.fold_left ( + fun set part -> + StringSet.add (Devsparts.part_to_dev part) set + ) StringSet.empty partitions in + let devices = List.filter ( + fun dev -> + not (StringSet.mem dev devices_containing_partitions) + ) devices in + + (* Use vfs-type to check for filesystems on devices. *) + let ret = filter_map check_with_vfs_type devices in + + (* Use vfs-type to check for filesystems on partitions, but + * ignore MBR partition type 42 used by LDM. + *) + let ret = + ret @ + filter_map ( + fun part -> + if not has_ldm || not (is_mbr_partition_type_42 part) then + check_with_vfs_type part + else + None (* ignore type 42 *) + ) partitions in + + (* Use vfs-type to check for filesystems on md devices. *) + let ret = ret @ filter_map check_with_vfs_type mds in + + (* LVM. *) + let ret = + if has_lvm2 then ( + let lvs = Lvm.lvs () in + (* Use vfs-type to check for filesystems on LVs. *) + ret @ filter_map check_with_vfs_type lvs + ) + else ret in + + (* LDM. *) + let ret = + if has_ldm then ( + let ldmvols = Ldm.list_ldm_volumes () in + let ldmparts = Ldm.list_ldm_partitions () in + (* Use vfs-type to check for filesystems on Windows dynamic disks. *) + ret @ + filter_map check_with_vfs_type ldmvols @ + filter_map check_with_vfs_type ldmparts + ) + else ret in + + List.flatten ret + +(* Use vfs-type to check for a filesystem of some sort of [device]. + * Returns [Some [device, vfs_type; ...]] if found (there may be + * multiple devices found in the case of btrfs), else [None] if nothing + * is found. + *) +and check_with_vfs_type device = + let mountable = Mountable.of_device device in + let vfs_type = + try Blkid.vfs_type mountable + with exn -> + if verbose () then + eprintf "check_with_vfs_type: %s: %s\n" + device (Printexc.to_string exn); + "" in + + if vfs_type = "" then + Some [mountable, "unknown"] + + (* Ignore all "*_member" strings. In libblkid these are returned + * for things which are members of some RAID or LVM set, most + * importantly "LVM2_member" which is a PV. + *) + else if String.is_suffix vfs_type "_member" then + None + + (* Ignore LUKS-encrypted partitions. These are also containers, as above. *) + else if vfs_type = "crypto_LUKS" then + None + + (* A single btrfs device can turn into many volumes. *) + else if vfs_type = "btrfs" then ( + let vols = Btrfs.btrfs_subvolume_list mountable in + + (* Filter out the default subvolume. You can access that by + * simply mounting the whole device, so we will add the whole + * device at the beginning of the returned list instead. + *) + let default_volume = Btrfs.btrfs_subvolume_get_default mountable in + let vols = + List.filter ( + fun { Btrfs.btrfssubvolume_id = id } -> id <> default_volume + ) vols in + + Some ( + (mountable, vfs_type) (* whole device = default volume *) + :: List.map ( + fun { Btrfs.btrfssubvolume_path = path } -> + let mountable = Mountable.of_btrfsvol device path in + (mountable, "btrfs") + ) vols + ) + ) + + else + Some [mountable, vfs_type] + +(* We should ignore partitions that have MBR type byte 0x42, because + * these are members of a Windows dynamic disk group. Trying to read + * them will cause errors (RHBZ#887520). Assuming that libguestfs was + * compiled with ldm support, we'll get the filesystems on these later. + *) +and is_mbr_partition_type_42 partition = + try + let partnum = Devsparts.part_to_partnum partition in + let device = Devsparts.part_to_dev partition in + let mbr_id = Parted.part_get_mbr_id device partnum in + mbr_id = 0x42 + with exn -> + if verbose () then + eprintf "is_mbr_partition_type_42: %s: %s\n" + partition (Printexc.to_string exn); + false diff --git a/daemon/listfs.mli b/daemon/listfs.mli new file mode 100644 index 000000000..69958da77 --- /dev/null +++ b/daemon/listfs.mli @@ -0,0 +1,19 @@ +(* 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 list_filesystems : unit -> (Mountable.t * string) list diff --git a/daemon/lvm.ml b/daemon/lvm.ml index 4a9156dad..b19bf93fd 100644 --- a/daemon/lvm.ml +++ b/daemon/lvm.ml @@ -22,6 +22,9 @@ open Std_utils open Utils +external available : unit -> bool = + "guestfs_int_daemon_optgroup_lvm2_available" "noalloc" + (* Check whether lvs has -S to filter its output. * It is available only in lvm2 >= 2.02.107. *) diff --git a/daemon/lvm.mli b/daemon/lvm.mli index f254728cb..1cf61ecfb 100644 --- a/daemon/lvm.mli +++ b/daemon/lvm.mli @@ -16,4 +16,6 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *) +val available : unit -> bool + val lvs : unit -> string list diff --git a/docs/C_SOURCE_FILES b/docs/C_SOURCE_FILES index 7ac6716cd..b4f085699 100644 --- a/docs/C_SOURCE_FILES +++ b/docs/C_SOURCE_FILES @@ -325,7 +325,6 @@ lib/launch.c lib/libvirt-auth.c lib/libvirt-domain.c lib/libvirt-is-version.c -lib/listfs.c lib/lpj.c lib/match.c lib/mountable.c diff --git a/generator/actions_core.ml b/generator/actions_core.ml index bd3c21d3b..d5946b3f5 100644 --- a/generator/actions_core.ml +++ b/generator/actions_core.ml @@ -209,43 +209,6 @@ If the mountable does not represent a btrfs subvolume, then this function fails and the C<errno> is set to C<EINVAL>." }; { defaults with - name = "list_filesystems"; added = (1, 5, 15); - style = RHashtable (RMountable, RPlainString, "fses"), [], []; - shortdesc = "list filesystems"; - longdesc = "\ -This inspection command looks for filesystems on partitions, -block devices and logical volumes, returning a list of C<mountables> -containing filesystems and their type. - -The return value is a hash, where the keys are the devices -containing filesystems, and the values are the filesystem types. -For example: - - \"/dev/sda1\" => \"ntfs\" - \"/dev/sda2\" => \"ext2\" - \"/dev/vg_guest/lv_root\" => \"ext4\" - \"/dev/vg_guest/lv_swap\" => \"swap\" - -The key is not necessarily a block device. It may also be an opaque -‘mountable’ string which can be passed to C<guestfs_mount>. - -The value can have the special value \"unknown\", meaning the -content of the device is undetermined or empty. -\"swap\" means a Linux swap partition. - -This command runs other libguestfs commands, which might include -C<guestfs_mount> and C<guestfs_umount>, and therefore you should -use this soon after launch and only when nothing is mounted. - -Not all of the filesystems returned will be mountable. In -particular, swap partitions are returned in the list. Also -this command does not check that each filesystem -found is valid and mountable, and some filesystems might -be mountable but require special options. Filesystems may -not all belong to a single logical operating system -(use C<guestfs_inspect_os> to look for OSes)." }; - - { defaults with name = "add_drive"; added = (0, 0, 3); style = RErr, [String (PlainString, "filename")], [OBool "readonly"; OString "format"; OString "iface"; OString "name"; OString "label"; OString "protocol"; OStringList "server"; OString "username"; OString "secret"; OString "cachemode"; OString "discard"; OBool "copyonread"]; once_had_no_optargs = true; @@ -9635,4 +9598,42 @@ initrd or kernel module(s) instead. =back" }; + { defaults with + name = "list_filesystems"; added = (1, 5, 15); + style = RHashtable (RMountable, RPlainString, "fses"), [], []; + impl = OCaml "Listfs.list_filesystems"; + shortdesc = "list filesystems"; + longdesc = "\ +This inspection command looks for filesystems on partitions, +block devices and logical volumes, returning a list of C<mountables> +containing filesystems and their type. + +The return value is a hash, where the keys are the devices +containing filesystems, and the values are the filesystem types. +For example: + + \"/dev/sda1\" => \"ntfs\" + \"/dev/sda2\" => \"ext2\" + \"/dev/vg_guest/lv_root\" => \"ext4\" + \"/dev/vg_guest/lv_swap\" => \"swap\" + +The key is not necessarily a block device. It may also be an opaque +‘mountable’ string which can be passed to C<guestfs_mount>. + +The value can have the special value \"unknown\", meaning the +content of the device is undetermined or empty. +\"swap\" means a Linux swap partition. + +This command runs other libguestfs commands, which might include +C<guestfs_mount> and C<guestfs_umount>, and therefore you should +use this soon after launch and only when nothing is mounted. + +Not all of the filesystems returned will be mountable. In +particular, swap partitions are returned in the list. Also +this command does not check that each filesystem +found is valid and mountable, and some filesystems might +be mountable but require special options. Filesystems may +not all belong to a single logical operating system +(use C<guestfs_inspect_os> to look for OSes)." }; + ] diff --git a/generator/proc_nr.ml b/generator/proc_nr.ml index 1b0feae87..dec02f5fa 100644 --- a/generator/proc_nr.ml +++ b/generator/proc_nr.ml @@ -483,6 +483,7 @@ let proc_nr = [ 473, "yara_destroy"; 474, "internal_yara_scan"; 475, "file_architecture"; +476, "list_filesystems"; ] (* End of list. If adding a new entry, add it at the end of the list diff --git a/lib/MAX_PROC_NR b/lib/MAX_PROC_NR index 7573eff88..b86395733 100644 --- a/lib/MAX_PROC_NR +++ b/lib/MAX_PROC_NR @@ -1 +1 @@ -475 +476 diff --git a/lib/Makefile.am b/lib/Makefile.am index fab8c4a45..cab03107f 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -109,7 +109,6 @@ libguestfs_la_SOURCES = \ launch-unix.c \ libvirt-auth.c \ libvirt-domain.c \ - listfs.c \ lpj.c \ match.c \ mountable.c \ diff --git a/lib/listfs.c b/lib/listfs.c deleted file mode 100644 index 60aff3305..000000000 --- a/lib/listfs.c +++ /dev/null @@ -1,246 +0,0 @@ -/* libguestfs - * Copyright (C) 2010 Red Hat Inc. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; 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 "guestfs.h" -#include "guestfs-internal.h" -#include "guestfs-internal-actions.h" -#include "structs-cleanups.h" - -/* List filesystems. - * - * The current implementation just uses guestfs_vfs_type and doesn't - * try mounting anything, but we reserve the right in future to try - * mounting filesystems. - */ - -static void remove_from_list (char **list, const char *item); -static int check_with_vfs_type (guestfs_h *g, const char *dev, struct stringsbuf *sb); -static int is_mbr_partition_type_42 (guestfs_h *g, const char *partition); - -char ** -guestfs_impl_list_filesystems (guestfs_h *g) -{ - size_t i; - DECLARE_STRINGSBUF (ret); - - const char *lvm2[] = { "lvm2", NULL }; - const int has_lvm2 = guestfs_feature_available (g, (char **) lvm2); - const char *ldm[] = { "ldm", NULL }; - const int has_ldm = guestfs_feature_available (g, (char **) ldm); - - CLEANUP_FREE_STRING_LIST char **devices = NULL; - CLEANUP_FREE_STRING_LIST char **partitions = NULL; - CLEANUP_FREE_STRING_LIST char **mds = NULL; - CLEANUP_FREE_STRING_LIST char **lvs = NULL; - CLEANUP_FREE_STRING_LIST char **ldmvols = NULL; - CLEANUP_FREE_STRING_LIST char **ldmparts = NULL; - - /* Look to see if any devices directly contain filesystems - * (RHBZ#590167). However vfs-type will fail to tell us anything - * useful about devices which just contain partitions, so we also - * get the list of partitions and exclude the corresponding devices - * by using part-to-dev. - */ - devices = guestfs_list_devices (g); - if (devices == NULL) goto error; - partitions = guestfs_list_partitions (g); - if (partitions == NULL) goto error; - mds = guestfs_list_md_devices (g); - if (mds == NULL) goto error; - - for (i = 0; partitions[i] != NULL; ++i) { - CLEANUP_FREE char *dev = guestfs_part_to_dev (g, partitions[i]); - if (dev) - remove_from_list (devices, dev); - } - - /* Use vfs-type to check for filesystems on devices. */ - for (i = 0; devices[i] != NULL; ++i) - if (check_with_vfs_type (g, devices[i], &ret) == -1) - goto error; - - /* Use vfs-type to check for filesystems on partitions. */ - for (i = 0; partitions[i] != NULL; ++i) { - if (has_ldm == 0 || ! is_mbr_partition_type_42 (g, partitions[i])) { - if (check_with_vfs_type (g, partitions[i], &ret) == -1) - goto error; - } - } - - /* Use vfs-type to check for filesystems on md devices. */ - for (i = 0; mds[i] != NULL; ++i) - if (check_with_vfs_type (g, mds[i], &ret) == -1) - goto error; - - if (has_lvm2 > 0) { - /* Use vfs-type to check for filesystems on LVs. */ - lvs = guestfs_lvs (g); - if (lvs == NULL) goto error; - - for (i = 0; lvs[i] != NULL; ++i) - if (check_with_vfs_type (g, lvs[i], &ret) == -1) - goto error; - } - - if (has_ldm > 0) { - /* Use vfs-type to check for filesystems on Windows dynamic disks. */ - ldmvols = guestfs_list_ldm_volumes (g); - if (ldmvols == NULL) goto error; - - for (i = 0; ldmvols[i] != NULL; ++i) - if (check_with_vfs_type (g, ldmvols[i], &ret) == -1) - goto error; - - ldmparts = guestfs_list_ldm_partitions (g); - if (ldmparts == NULL) goto error; - - for (i = 0; ldmparts[i] != NULL; ++i) - if (check_with_vfs_type (g, ldmparts[i], &ret) == -1) - goto error; - } - - /* Finish off the list and return it. */ - guestfs_int_end_stringsbuf (g, &ret); - return ret.argv; - - error: - guestfs_int_free_stringsbuf (&ret); - return NULL; -} - -/* If 'item' occurs in 'list', remove and free it. */ -static void -remove_from_list (char **list, const char *item) -{ - size_t i; - - for (i = 0; list[i] != NULL; ++i) - if (STREQ (list[i], item)) { - free (list[i]); - for (; list[i+1] != NULL; ++i) - list[i] = list[i+1]; - list[i] = NULL; - return; - } -} - -/* Use vfs-type to look for a filesystem of some sort on 'dev'. - * Apart from some types which we ignore, add the result to the - * 'ret' string list. - */ -static int -check_with_vfs_type (guestfs_h *g, const char *device, struct stringsbuf *sb) -{ - const char *v; - CLEANUP_FREE char *vfs_type = NULL; - - guestfs_push_error_handler (g, NULL, NULL); - vfs_type = guestfs_vfs_type (g, device); - guestfs_pop_error_handler (g); - - if (!vfs_type) - v = "unknown"; - else if (STREQ (vfs_type, "")) - v = "unknown"; - else if (STREQ (vfs_type, "btrfs")) { - CLEANUP_FREE_BTRFSSUBVOLUME_LIST struct guestfs_btrfssubvolume_list *vols = - guestfs_btrfs_subvolume_list (g, device); - - if (vols == NULL) - return -1; - - const int64_t default_volume = - guestfs_btrfs_subvolume_get_default (g, device); - - for (size_t i = 0; i < vols->len; i++) { - struct guestfs_btrfssubvolume *this = &vols->val[i]; - - /* Ignore the default subvolume. We get it by simply mounting - * the whole device of this btrfs filesystem. - */ - if (this->btrfssubvolume_id == (uint64_t) default_volume) - continue; - - guestfs_int_add_sprintf (g, sb, - "btrfsvol:%s/%s", - device, this->btrfssubvolume_path); - guestfs_int_add_string (g, sb, "btrfs"); - } - - v = vfs_type; - } - else { - /* Ignore all "*_member" strings. In libblkid these are returned - * for things which are members of some RAID or LVM set, most - * importantly "LVM2_member" which is a PV. - */ - const size_t n = strlen (vfs_type); - if (n >= 7 && STREQ (&vfs_type[n-7], "_member")) - return 0; - - /* Ignore LUKS-encrypted partitions. These are also containers. */ - if (STREQ (vfs_type, "crypto_LUKS")) - return 0; - - v = vfs_type; - } - - guestfs_int_add_string (g, sb, device); - guestfs_int_add_string (g, sb, v); - - return 0; -} - -/* We should ignore partitions that have MBR type byte 0x42, because - * these are members of a Windows dynamic disk group. Trying to read - * them will cause errors (RHBZ#887520). Assuming that libguestfs was - * compiled with ldm support, we'll get the filesystems on these later. - */ -static int -is_mbr_partition_type_42 (guestfs_h *g, const char *partition) -{ - CLEANUP_FREE char *device = NULL; - int partnum; - int mbr_id; - int ret = 0; - - guestfs_push_error_handler (g, NULL, NULL); - - partnum = guestfs_part_to_partnum (g, partition); - if (partnum == -1) - goto out; - - device = guestfs_part_to_dev (g, partition); - if (device == NULL) - goto out; - - mbr_id = guestfs_part_get_mbr_id (g, device, partnum); - - ret = mbr_id == 0x42; - - out: - guestfs_pop_error_handler (g); - - return ret; -} -- 2.13.2