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| author | Richard W.M. Jones <rjones@redhat.com> | 2012-07-09 15:23:52 +0100 |
|---|---|---|
| committer | Richard W.M. Jones <rjones@redhat.com> | 2012-07-09 22:26:09 +0100 |
| commit | 1ac10106665c16a6961e4a14ae15017003127932 (patch) | |
| tree | bbbefde8f927335ac4fe2ce563624089c94ff8e1 | |
| parent | 72540bd9a673d47ecef622906cb0ee844e212732 (diff) | |
| download | libguestfs-1ac10106665c16a6961e4a14ae15017003127932.tar.gz libguestfs-1ac10106665c16a6961e4a14ae15017003127932.tar.xz libguestfs-1ac10106665c16a6961e4a14ae15017003127932.zip | |
fuse: Document race condition possible with fusermount.
See also:
https://bugzilla.redhat.com/show_bug.cgi?id=835466#c9
(cherry picked from commit 1cde66165aac222f1a07ad4c3873c61d49eabb02)
| -rw-r--r-- | fuse/guestmount.pod | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fuse/guestmount.pod b/fuse/guestmount.pod index a0bc6f14..c37301c9 100644 --- a/fuse/guestmount.pod +++ b/fuse/guestmount.pod @@ -106,6 +106,22 @@ namespace using the Linux-specific L<clone(2)>/L<unshare(2)> flag C<CLONE_NEWNS>. Unfortunately at the moment this requires root and we would also probably need to add it as a feature to guestmount. +=head2 Race conditions possible when shutting down the connection + +When C<fusermount -u> exits, guestmount may still be running and +cleaning up the mountpoint. The disk image will not be fully +finalized. + +This means that scripts like the following have a nasty race +condition: + + guestmount -a disk.img -i /mnt + # copy things into /mnt + fusermount -u /mnt + # immediately try to use 'disk.img' <-- UNSAFE + +The solution is to spin waiting for the guestmount process to exit. + =head1 OPTIONS =over 4 |