On Fri, Jun 22, 2012 at 09:59:58AM -0400, Daniel J Walsh wrote:

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Currently libvirt-lxc checks to see if the destination exists and is a directory. If it is not a directory then the mount fails. Since libvirt-lxc can bind mount files on an inode, this patch is needed to allow us to bind mount files on files. Currently we want to bind mount on top of /etc/machine-id, and /etc/adjtime

If the destination of the mount point does not exists, it checks if the src is a directory and then attempts to create a directory, otherwise it creates an empty file for the destination. The code will then bind mount over the destination.

Current code blows up if the destination was not a directory. We want to be able to bind mount files on files.

Sorry if you are seeing this patch for the second time, since I sent it to the wrong list. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

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diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 24b1017..6cd8760 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -648,17 +665,37 @@ static int lxcContainerMountFSBind(virDomainFSDefPtr fs, { char *src = NULL; int ret = -1; + struct stat st;

if (virAsprintf(&src, "%s%s", srcprefix, fs->src) < 0) { virReportOOMError(); goto cleanup; }

- if (virFileMakePath(fs->dst) < 0) { - virReportSystemError(errno, - _("Failed to create %s"), - fs->dst); - goto cleanup; + if ((stat(fs->dst, &st) < 0) && (errno == ENOENT)) { + if (stat(src, &st) >= 0) {

We should be reporting errors if either of the stat() calls fails.

+ if (S_ISDIR(st.st_mode)) { + if (virFileMakePath(fs->dst) < 0) { + virReportSystemError(errno, + _("Failed to create %s"), + fs->dst); + goto cleanup; + } + } else { + /* Create Empty file for target mount point */ + int fd = open(fs->dst, O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666); + if (fd >= 0) { + close(fd);

This needs to be VIR_CLOSE & have it exit stats checked, since close() can fail (particularly on NFS).

+ } else { + if (errno != EEXIST) { + virReportSystemError(errno, + _("Failed to create %s"), + fs->dst); + goto cleanup; + } + } + } + }

I'm applying the following variation on your patch which fixes the issues I mention above: - if (virFileMakePath(fs->dst) < 0) { - virReportSystemError(errno, - _("Failed to create %s"), - fs->dst); - goto cleanup; + if (stat(fs->dst, &st) < 0) { + if (errno != ENOENT) { + virReportSystemError(errno, _("Unable to stat bind target %s"), + fs->dst); + goto cleanup; + } + /* ENOENT => create the target dir or file */ + if (stat(src, &st) < 0) { + virReportSystemError(errno, _("Unable to stat bind source %s"), + src); + goto cleanup; + } + if (S_ISDIR(st.st_mode)) { + if (virFileMakePath(fs->dst) < 0) { + virReportSystemError(errno, + _("Failed to create %s"), + fs->dst); + goto cleanup; + } + } else { + /* Create Empty file for target mount point */ + int fd = open(fs->dst, O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666); + if (fd < 0) { + if (errno != EEXIST) { + virReportSystemError(errno, + _("Failed to create bind target %s"), + fs->dst); + goto cleanup; + } + } + if (VIR_CLOSE(fd) < 0) { + virReportSystemError(errno, + _("Failed to close bind target %s"), + fs->dst); + goto cleanup; + } + } Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|