From c18a88ac489c5356734bb7cff59f8fc73c9d1227 Mon Sep 17 00:00:00 2001 From: Laine Stump Date: Thu, 12 Jan 2012 13:24:45 -0500 Subject: [PATCH] qemu: eliminate "Ignoring open failure" when using root-squash NFS This eliminates the warning message reported in: https://bugzilla.redhat.com/show_bug.cgi?id=624447 It was caused by a failure to open an image file that is not accessible by root (the uid libvirtd is running as) because it's on a root-squash NFS share, owned by a different user, with permissions of 660 (or maybe 600). The solution is to use virFileOpenAs() rather than open(). The codepath that generates the error is during qemuSetupDiskCGroup(), but the actual open() is in a lower-level generic function called from many places (virDomainDiskDefForeachPath), so some other pieces of the code were touched just to add dummy (or possibly useful) uid and gid arguments. Eliminating this warning message has the nice side effect that the requested operation may even succeed (which in this case isn't necessary, but shouldn't hurt anything either). --- src/conf/domain_conf.c | 8 ++++---- src/conf/domain_conf.h | 1 + src/qemu/qemu_cgroup.c | 2 ++ src/security/security_dac.c | 1 + src/security/security_selinux.c | 7 +++++++ src/security/virt-aa-helper.c | 6 +++++- 6 files changed, 20 insertions(+), 5 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index dcb9549843..aa4b32d12b 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -13554,6 +13554,7 @@ done: int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk, bool allowProbing, bool ignoreOpenFailure, + uid_t uid, gid_t gid, virDomainDiskDefPathIterator iter, void *opaque) { @@ -13610,15 +13611,14 @@ int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk, goto cleanup; } - if ((fd = open(path, O_RDONLY)) < 0) { + if ((fd = virFileOpenAs(path, O_RDONLY, 0, uid, gid, 0)) < 0) { if (ignoreOpenFailure) { char ebuf[1024]; VIR_WARN("Ignoring open failure on %s: %s", path, - virStrerror(errno, ebuf, sizeof(ebuf))); + virStrerror(-fd, ebuf, sizeof(ebuf))); break; } else { - virReportSystemError(errno, - _("unable to open disk path %s"), + virReportSystemError(-fd, _("unable to open disk path %s"), path); goto cleanup; } diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index e3c9af8613..0a2795df9a 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1974,6 +1974,7 @@ typedef int (*virDomainDiskDefPathIterator)(virDomainDiskDefPtr disk, int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk, bool allowProbing, bool ignoreOpenFailure, + uid_t uid, gid_t gid, virDomainDiskDefPathIterator iter, void *opaque); diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 2d970d6986..a07b6cdb20 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -96,6 +96,7 @@ int qemuSetupDiskCgroup(struct qemud_driver *driver, return virDomainDiskDefForeachPath(disk, driver->allowDiskFormatProbing, true, + driver->user, driver->group, qemuSetupDiskPathAllow, &data); } @@ -137,6 +138,7 @@ int qemuTeardownDiskCgroup(struct qemud_driver *driver, return virDomainDiskDefForeachPath(disk, driver->allowDiskFormatProbing, true, + driver->user, driver->group, qemuTeardownDiskPathDeny, &data); } diff --git a/src/security/security_dac.c b/src/security/security_dac.c index 2fb4a147f7..3e1a72f361 100644 --- a/src/security/security_dac.c +++ b/src/security/security_dac.c @@ -186,6 +186,7 @@ virSecurityDACSetSecurityImageLabel(virSecurityManagerPtr mgr, return virDomainDiskDefForeachPath(disk, virSecurityManagerGetAllowDiskFormatProbing(mgr), false, + priv->user, priv->group, virSecurityDACSetSecurityFileLabel, mgr); } diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c index 15b80c4d71..d5f35ddbdd 100644 --- a/src/security/security_selinux.c +++ b/src/security/security_selinux.c @@ -689,9 +689,16 @@ SELinuxSetSecurityImageLabel(virSecurityManagerPtr mgr, if (disk->type == VIR_DOMAIN_DISK_TYPE_NETWORK) return 0; + /* XXX On one hand, it would be nice to have the driver's uid:gid + * here so we could retry opens with it. On the other hand, it + * probably doesn't matter because in practice that's only useful + * for files on root-squashed NFS shares, and NFS doesn't properly + * support selinux anyway. + */ return virDomainDiskDefForeachPath(disk, allowDiskFormatProbing, true, + -1, -1, /* current process uid:gid */ SELinuxSetSecurityFileLabel, secdef); } diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index b484a2029e..1971f4011e 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -910,10 +910,14 @@ get_files(vahControl * ctl) /* XXX passing ignoreOpenFailure = true to get back to the behavior * from before using virDomainDiskDefForeachPath. actually we should * be passing ignoreOpenFailure = false and handle open errors more - * careful than just ignoring them */ + * careful than just ignoring them. + * XXX2 - if we knew the qemu user:group here we could send it in + * so that the open could be re-tried as that user:group. + */ int ret = virDomainDiskDefForeachPath(ctl->def->disks[i], ctl->allowDiskFormatProbing, true, + -1, -1 /* current uid:gid */ add_file_path, &buf); if (ret != 0) -- GitLab