I need to detect the triggering of an auto-mount operation when accessing the path to a formerly unknown mount point at the file system (BSD, POSIX, NSURL) level, and how to wait for it to finish the operation. Network shares can have sub-volumes on them Consider a Windows server. Let's say there's a SMB sharepoint at C:\Shared. It has some folders, one of which is at C:\Shared\More. Furthermore, there's another partition (volume) on the PC, which is mounted at C:\Shared\More\OtherVol. If you mount the initial share on a Mac with a recent macOS, macOS initially only sees a single mount point at /Volumes/Shared, which can be checked with the "mount" command. Now, if you use Finder to dive into the Shared/More folder, Finder will trigger an auto-mount action on the containing OtherVol folder, and after that, the "mount" command will list two mount points from this server, the second being at /Volumes/Shared/More/OtherVol. (This was a bit surprising to me - I'd have thought that Windows or SMB would hide the fact that the share has sub-volumes, and simply show them as directories - and that's what it did in older macOS versions indeed, e.g. in High Sierra. But in Sequoia, these sub-volumes on the Windows side are mirrored on the Mac side, and they behave accordingly) Browse the volume, including its sub-volumes Now, I have a program that tries to dive into all the folders of this Shared volume, even if it was just freshly mounted and there's no mountpoint at /Volumes/Shared/More/OtherVol known yet (i.e. the user didn't use Finder to explore it). This means, that if my program, e.g. using a simple recursive directory scan, reaches /Volumes/Shared/More/OtherVol, the item will not appear as a volume but as an empty folder. E.g, if I get the NSURLIsVolumeKey value, it'll be false. Only once I try to enter the empty dir, listing its contents, which will return no items, an auto-mount action will get triggered, which will add the mountpoint at the path. So, in order to browse the actual contents of the OtherVol directory, I'd have to detect this auto-mount operation somehow, wait for it to finish mounting, and then re-enter the same directory so that I now see the mounted content. How do I do that? I.e. how do I tell that a dir is actually a auto-mount point and how do I wait for it to get auto-mounted before I continue to browse its contents? Note that newer macOS versions do not use fstab any more, so that's of no help here. Can the DA API help? Do I need to use the old Disk Arbitration functions for this, somehow? I have used the DA framework in the part to prevent auto-mounting, so I imagine I could hook into that handler, and if I get a callback for a mount operation, I could then queue the newly mounted volume for scanning. The problem, however, is that my scanning code may, having only seen an empty directory at the not-yet-mounted mountpoint, already decided that there's nothing there and finished its operation. I'd need some reliable method that lets my recursive scanning code know whether an auto-mount has been triggered and it therefore needs to wait for the DA callback. So, is there some signal that will let me know IMMEDIATELY after entering the empty mountpoint directory that an auto-mount op is on the way? Because I suspect that the DA callbacks come with a delay, and therefore would come too late if I used that as the notifier that I have to wait.

I’m attempting to make an app that uses Disk Arbitration to intercept a disk mount (by creating and returning a dissenter in the appropriate callback) and then mount the disk with certain options (specifically, read-only, nobrowse, or both, depending on user options). For example: DADiskMountWithArguments(disk, nil, DADiskMountOptions(kDADiskMountOptionDefault), nil, nil, kReadOnly) …where kReadOnly is a pointer to an array only containing a “rdonly” CFString. While DADiskMountWithArguments seems to be usable in a sandboxed app for disk images, it doesn’t work when the disk is an external disk (e.g. connected via USB). I see lines like this in Console.app when this happens: Sandbox denied authorizing right 'system.volume.external.mount' by client '/path/to/exe' [17934] (engine 580) I’ve identified two workarounds that allow this to work in a sandbox, but both have their own problems: If a LaunchDaemon (even a sandboxed one, which is required for registration with SMAppService.daemon from the sandboxed app) does the call to DADiskMountWithArguments, it will succeed. But App Store policies don’t allow escalation to root. If I use the undocumented entitlement com.apple.security.temporary-exception.sbpl with a value of (allow authorization-right-obtain (right-name "system.volume.external.mount")), the mount works without escalation to root. But I understand that App Review is likely to reject the use of this entitlement, and that this entitlement isn't supported to begin with. Specifically, these are the behaviors I see on macOS Sequoia 15.3.1 and Xcode 16.2. Since I would like to try to publish this app on the App Store, neither of these seem like acceptable solutions. I don’t see why this should be restricted if the sandboxed app is not declaring a special path (i.e. the path in DADiskMountWithArguments is set to nil) and still does not have access to the mounted filesystem - am I missing something/is there a way to accomplish this?

When using external NVMe devices on iOS / iPadOS I cannot tell how to access the disk SMART data. On macOS I can use NVMeSMARTLibExternal.h to access this information but the same system does not seem to work on iPadOS (even with Thunderbolt NVMe devices). When using M series iPads with professional Thunderbolt storage this woudlbe very useful.