Hi,
Could you pull this into the net-next tree please (it has been pulled into
the vfs tree[1])? Besides fixing an rmmod bug, the changes made to the AFS
filesystem make it easier to use the AF_RXRPC RxGK (GSSAPI) security
class[2].
More specifically, these changes make it easier to map from the rxrpc_peer
record back to the afs_server record, thereby making it easier for AF_RXRPC
to reach out to the AFS filesystem to obtain a token to include in the
RESPONSE packet sent in reply to the AFS fileserver's security challenge.
The fileserver can then use this token to set up a secure connection back
to the client for the purpose of encrypted notifications.
These changes fix an occasional hang that's only really encountered when
rmmod'ing the kafs module, one of the reasons why I'm proposing it for the
next merge window rather than immediate upstreaming. The changes include:
(1) Remove the "-o autocell" mount option. This is obsolete with the
dynamic root and removing it makes the next patch slightly easier.
(2) Change how the dynamic root mount is constructed. Currently, the root
directory is (de)populated when it is (un)mounted if there are cells
already configured and, further, pairs of automount points have to be
created/removed each time a cell is added/deleted.
This is changed so that readdir on the root dir lists all the known
cell automount pairs plus the @cell symlinks and the inodes and
dentries are constructed by lookup on demand. This simplifies the
cell management code.
(3) A few improvements to the afs_volume tracepoint.
(4) A few improvements to the afs_server tracepoint.
(5) Pass trace info into the afs_lookup_cell() function to allow the trace
log to indicate the purpose of the lookup.
(6) Remove the 'net' parameter from afs_unuse_cell() as it's superfluous.
(7) In rxrpc, allow a kernel app (such as kafs) to store a word of
information on rxrpc_peer records.
(8) Use the information stored on the rxrpc_peer record to point to the
afs_server record. This allows the server address lookup to be done
away with.
(9) Simplify the afs_server ref/activity accounting to make each one
self-contained and not garbage collected from the cell management work
item.
(10) Simplify the afs_cell ref/activity accounting to make each one of
these also self-contained and not driven by a central management work
item.
The current code was intended to make it such that a single timer for
the namespace and one work item per cell could do all the work
required to maintain these records. This, however, made for some
sequencing problems when cleaning up these records. Further, the
attempt to pass refs along with timers and work items made getting it
right rather tricky when the timer or work item already had a ref
attached and now a ref had to be got rid of.
Thanks,
David
Link: https://lore.kernel.org/r/20250310094206.801057-1-dhowells@xxxxxxxxxx/ [1]
Link: https://web.git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-next [2]
---
The following changes since commit 1e15510b71c99c6e49134d756df91069f7d18141:
Merge tag 'net-6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (2025-02-27 09:32:42 -0800)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git tags/afs-next-20250310
for you to fetch changes up to e2c2cb8ef07affd9f69497ea128fa801240fdf32:
afs: Simplify cell record handling (2025-03-10 09:47:15 +0000)
----------------------------------------------------------------
afs: Fix ref leak in rmmod
----------------------------------------------------------------
David Howells (11):
afs: Fix afs_atcell_get_link() to handle RCU pathwalk
afs: Remove the "autocell" mount option
afs: Change dynroot to create contents on demand
afs: Improve afs_volume tracing to display a debug ID
afs: Improve server refcount/active count tracing
afs: Make afs_lookup_cell() take a trace note
afs: Drop the net parameter from afs_unuse_cell()
rxrpc: Allow the app to store private data on peer structs
afs: Use the per-peer app data provided by rxrpc
afs: Fix afs_server ref accounting
afs: Simplify cell record handling
fs/afs/addr_list.c | 50 ++++
fs/afs/cell.c | 446 ++++++++++++++-------------------
fs/afs/cmservice.c | 82 +------
fs/afs/dir.c | 5 +-
fs/afs/dynroot.c | 501 ++++++++++++++++---------------------
fs/afs/fs_probe.c | 32 ++-
fs/afs/fsclient.c | 4 +-
fs/afs/internal.h | 100 ++++----
fs/afs/main.c | 16 +-
fs/afs/mntpt.c | 5 +-
fs/afs/proc.c | 19 +-
fs/afs/rxrpc.c | 8 +-
fs/afs/server.c | 601 +++++++++++++++++++--------------------------
fs/afs/server_list.c | 6 +-
fs/afs/super.c | 25 +-
fs/afs/vl_alias.c | 7 +-
fs/afs/vl_rotate.c | 2 +-
fs/afs/volume.c | 15 +-
include/net/af_rxrpc.h | 2 +
include/trace/events/afs.h | 83 ++++---
net/rxrpc/ar-internal.h | 1 +
net/rxrpc/peer_object.c | 30 ++-
22 files changed, 927 insertions(+), 1113 deletions(-)
