From 3dc413c7bd82ddb93a3c7e25d15002a15e0e250c Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Thu, 12 Mar 2009 18:46:26 +0000 Subject: blktapctrl: Fix too early close of pipes Connections to ioemu have single_handler set, so they are closed as soon as all images of a certain type are closed. This is wrong with ioemu: All images that belong to the same domain are handled by the same backend process (usually qemu-dm, but also tapdisk-ioemu for domains without device model), regardless of the image type. This patch checks for the same-domain condition for ioemu connections. Signed-off-by: Kevin Wolf --- tools/blktap/drivers/blktapctrl.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'tools/blktap') diff --git a/tools/blktap/drivers/blktapctrl.c b/tools/blktap/drivers/blktapctrl.c index b7ee572837..21cdfe5239 100644 --- a/tools/blktap/drivers/blktapctrl.c +++ b/tools/blktap/drivers/blktapctrl.c @@ -231,6 +231,24 @@ static void add_disktype(blkif_t *blkif, int type) entry->pprev = pprev; } +static int qemu_instance_has_disks(pid_t pid) +{ + int i; + int count = 0; + driver_list_entry_t *entry; + + for (i = 0; i < MAX_DISK_TYPES; i++) { + entry = active_disks[i]; + while (entry) { + if ((entry->blkif->tappid == pid) && dtypes[i]->use_ioemu) + count++; + entry = entry->next; + } + } + + return (count != 0); +} + static int del_disktype(blkif_t *blkif) { driver_list_entry_t *entry, **pprev; @@ -255,6 +273,14 @@ static int del_disktype(blkif_t *blkif) DPRINTF("DEL_DISKTYPE: Freeing entry\n"); free(entry); + /* + * When using ioemu, all disks of one VM are connected to the same + * qemu-dm instance. We may close the file handle only if there is + * no other disk left for this domain. + */ + if (dtypes[type]->use_ioemu) + return !qemu_instance_has_disks(blkif->tappid); + /* Caller should close() if no single controller, or list is empty. */ return (!dtypes[type]->single_handler || (active_disks[type] == NULL)); } @@ -721,6 +747,7 @@ static int unmap_blktapctrl(blkif_t *blkif) } if (del_disktype(blkif)) { + DPRINTF("Closing communication pipe to pid %d\n", blkif->tappid); close(blkif->fds[WRITE]); close(blkif->fds[READ]); } -- cgit v1.2.3