Re: [Libguestfs] [PATCH libguestfs-common] options: Don't attempt to scan LVs if "lvm2" feature is not available

Since we added support for transparent decryption of LUKS in commit a232e62dcf ("fish: '-i' option automatically handles whole-disk encryption") we have always assumed that the "lvm2" feature is available and so we could call guestfs_vg_activate_all. That API would have failed in the unlikely event that the feature is not available, preventing opening any (even unencrypted) disk. The code has changed greatly since then but the basic problem remains. Test for the "lvm2" feature, otherwise avoid trying to scan LVs. Reported-by: Feng Li Fixes: a232e62dcf --- options/decrypt.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/options/decrypt.c b/options/decrypt.c index 6fc7760e3..19fe93ce2 100644 --- a/options/decrypt.c +++ b/options/decrypt.c @@ -202,8 +202,8 @@ decrypt_mountables (guestfs_h *g, const char * const *mountables, void inspect_do_decrypt (guestfs_h *g, struct key_store *ks) { + const char *lvm2_feature[] = { "lvm2", NULL }; CLEANUP_FREE_STRING_LIST char **partitions = guestfs_list_partitions (g); - CLEANUP_FREE_STRING_LIST char **lvs = NULL; bool need_rescan; if (partitions == NULL) @@ -211,13 +211,17 @@ inspect_do_decrypt (guestfs_h *g, struct key_store *ks) need_rescan = decrypt_mountables (g, (const char * const *)partitions, ks); - if (need_rescan) { - if (guestfs_lvm_scan (g, 1) == -1) + if (guestfs_feature_available (g, (char **) lvm2_feature) > 0) { + CLEANUP_FREE_STRING_LIST char **lvs = NULL; + + if (need_rescan) { + if (guestfs_lvm_scan (g, 1) == -1) + exit (EXIT_FAILURE); + } + + lvs = guestfs_lvs (g); + if (lvs == NULL) exit (EXIT_FAILURE); + decrypt_mountables (g, (const char * const *)lvs, ks); } - - lvs = guestfs_lvs (g); - if (lvs == NULL) - exit (EXIT_FAILURE); - decrypt_mountables (g, (const char * const *)lvs, ks); }