afs: Fix afs_getattr() to refetch file status if callback break occurred
If a callback break occurs (change notification), afs_getattr() needs to issue an FS.FetchStatus RPC operation to update the status of the file being examined by the stat-family of system calls. Fix afs_getattr() to do this if AFS_VNODE_CB_PROMISED has been cleared on a vnode by a callback break. Skip this if AT_STATX_DONT_SYNC is set. This can be tested by appending to a file on one AFS client and then using "stat -L" to examine its length on a machine running kafs. This can also be watched through tracing on the kafs machine. The callback break is seen: kworker/1:1-46 [001] ..... 978.910812: afs_cb_call: c=0000005f YFSCB.CallBack kworker/1:1-46 [001] ...1. 978.910829: afs_cb_break: 100058:23b4c:242d2c2 b=2 s=1 break-cb kworker/1:1-46 [001] ..... 978.911062: afs_call_done: c=0000005f ret=0 ab=0 [0000000082994ead] And then the stat command generated no traffic if unpatched, but with this change a call to fetch the status can be observed: stat-4471 [000] ..... 986.744122: afs_make_fs_call: c=000000ab 100058:023b4c:242d2c2 YFS.FetchStatus stat-4471 [000] ..... 986.745578: afs_call_done: c=000000ab ret=0 ab=0 [0000000087fc8c84] Fixes: 08e0e7c8 ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.") Reported-by:Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by:
David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Tested-by:
Markus Suvanto <markus.suvanto@gmail.com> Tested-by:
<kafs-testing+fedora34_64checkkafs-build-496@auristor.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216010 Link: https://lore.kernel.org/r/165308359800.162686.14122417881564420962.stgit@warthog.procyon.org.uk/ # v1 Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
parent
978df3e1