From 661c0fee958d993b5c8d4600998ba0fdbf43da11 Mon Sep 17 00:00:00 2001 From: Konstantin Kostiuk Date: Wed, 18 Dec 2024 18:49:04 +0200 Subject: [PATCH] qga: skip bind mounts in fs list RH-Author: Konstantin Kostiuk RH-MergeRequest: 423: qga: skip bind mounts in fs list RH-Jira: RHEL-59214 RH-Acked-by: yvugenfi RH-Acked-by: Jon Maloy RH-Commit: [1/1] 2ebf2a4dba0e2da9d077c116accd12dc7f3dbcd1 The filesystem list in build_fs_mount_list should skip bind mounts. This because we end up in locking situations when doing fsFreeze. Like mentioned in [1] and [2]. Next to that, the build_fs_mount_list call did a fallback via build_fs_mount_list_from_mtab if mountinfo did not exist. There it skipped bind mounts, but this is broken for newer OS. This as mounts does not return the path of the bind mount but the underlying dev/partition, so S_ISDIR will never return true in dev_major_minor call. This patch simply checks the existing devmajor:devminor tuple in the mounts, and if it already exists, this means we have the same devices mounted again, a bind mount. So skip this. Same approach is used in open-vm-tools [3]. [1]: https://gitlab.com/qemu-project/qemu/-/issues/592 [2]: https://gitlab.com/qemu-project/qemu/-/issues/520 [3]: https://github.com/vmware/open-vm-tools/commit/d58847b497e212737007958c945af1df22a8ab58 Signed-off-by: Jean-Louis Dupond Reviewed-by: Konstantin Kostiuk Link: https://lore.kernel.org/r/20241002100634.162499-2-jean-louis@dupond.be Signed-off-by: Konstantin Kostiuk --- qga/commands-posix.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 75dbaab68e..dce0d1551f 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -668,6 +668,22 @@ static int dev_major_minor(const char *devpath, return -1; } +/* + * Check if we already have the devmajor:devminor in the mounts + * If thats the case return true. + */ +static bool dev_exists(FsMountList *mounts, unsigned int devmajor, unsigned int devminor) +{ + FsMount *mount; + + QTAILQ_FOREACH(mount, mounts, next) { + if (mount->devmajor == devmajor && mount->devminor == devminor) { + return true; + } + } + return false; +} + /* * Walk the mount table and build a list of local file systems */ @@ -701,6 +717,10 @@ static void build_fs_mount_list_from_mtab(FsMountList *mounts, Error **errp) /* Skip bind mounts */ continue; } + if (dev_exists(mounts, devmajor, devminor)) { + /* Skip already existing devices (bind mounts) */ + continue; + } mount = g_new0(FsMount, 1); mount->dirname = g_strdup(ment->mnt_dir); @@ -780,6 +800,11 @@ static void build_fs_mount_list(FsMountList *mounts, Error **errp) continue; } } + + if (dev_exists(mounts, devmajor, devminor)) { + /* Skip already existing devices (bind mounts) */ + continue; + } mount = g_new0(FsMount, 1); mount->dirname = g_strdup(line + dir_s); -- 2.47.1