From 609f45263a676fec5baef7a1c233b3a153fd9b21 Mon Sep 17 00:00:00 2001 From: Jes Sorensen Date: Wed, 9 Mar 2011 15:41:00 -0300 Subject: [PATCH] Improve error handling in do_snapshot_blkdev() RH-Author: Jes Sorensen Message-id: <1299685260-24746-1-git-send-email-Jes.Sorensen@redhat.com> Patchwork-id: 19760 O-Subject: [RHEL6.1 qemu-kvm PATCH v4] Improve error handling in do_snapshot_blkdev() Bugzilla: 676529 RH-Acked-by: Juan Quintela RH-Acked-by: Alex Williamson RH-Acked-by: Kevin Wolf From: Jes Sorensen Upstream status: Posted Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=676529 In case we cannot open the newly created snapshot image, try to fall back to the original image file and continue running on that, which should prevent the guest from aborting. This is a corner case which can happen if the admin by mistake specifies the snapshot file on a virtual file system which does not support O_DIRECT. bdrv_create() does not use O_DIRECT, but the following open in bdrv_open() does and will then fail. Signed-off-by: Jes Sorensen --- monitor.c | 23 +++++++++++++++++------ 1 files changed, 17 insertions(+), 6 deletions(-) Signed-off-by: Luiz Capitulino --- monitor.c | 23 +++++++++++++++++------ 1 files changed, 17 insertions(+), 6 deletions(-) diff --git a/monitor.c b/monitor.c index 796d745..e80cc66 100644 --- a/monitor.c +++ b/monitor.c @@ -1053,9 +1053,10 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) const char *filename = qdict_get_try_str(qdict, "snapshot_file"); const char *format = qdict_get_try_str(qdict, "format"); BlockDriverState *bs; - BlockDriver *drv, *proto_drv; + BlockDriver *drv, *old_drv, *proto_drv; int ret = 0; int flags; + char old_filename[1024]; if (!filename) { qerror_report(QERR_MISSING_PARAMETER, "snapshot_file"); @@ -1070,6 +1071,11 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) goto out; } + pstrcpy(old_filename, sizeof(old_filename), bs->filename); + + old_drv = bs->drv; + flags = bs->open_flags; + if (!format) { format = "qcow2"; } @@ -1089,7 +1095,7 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) } ret = bdrv_img_create(filename, format, bs->filename, - bs->drv->format_name, NULL, -1, bs->open_flags); + bs->drv->format_name, NULL, -1, flags); if (ret) { goto out; } @@ -1097,15 +1103,20 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) qemu_aio_flush(); bdrv_flush(bs); - flags = bs->open_flags; bdrv_close(bs); ret = bdrv_open(bs, filename, flags, drv); /* - * If reopening the image file we just created fails, we really - * are in trouble :( + * If reopening the image file we just created fails, fall back + * and try to re-open the original image. If that fails too, we + * are in serious trouble. */ if (ret != 0) { - abort(); + ret = bdrv_open(bs, old_filename, flags, old_drv); + if (ret != 0) { + qerror_report(QERR_OPEN_FILE_FAILED, old_filename); + } else { + qerror_report(QERR_OPEN_FILE_FAILED, filename); + } } out: if (ret) { -- 1.7.4.rc1.16.gd2f15e