kernel.git/include/trace/events/afs.h, branch linux-5.8.y

afs: Add a tracepoint to track the lifetime of the afs_volume struct

2020-06-04T14:37:57Z

Add a tracepoint to track the lifetime of the afs_volume struct. Signed-off-by: David Howells

afs: Implement client support for the YFSVL.GetCellName RPC op

2020-06-04T14:37:57Z

Implement client support for the YFSVL.GetCellName RPC operation by which YFS permits the canonical cell name to be queried from a VL server. Signed-off-by: David Howells

afs: Build an abstraction around an "operation" concept

2020-06-04T14:37:17Z

Turn the afs_operation struct into the main way that most fileserver operations are managed. Various things are added to the struct, including the following: (1) All the parameters and results of the relevant operations are moved into it, removing corresponding fields from the afs_call struct. afs_call gets a pointer to the op. (2) The target volume is made the main focus of the operation, rather than the target vnode(s), and a bunch of op->vnode->volume are made op->volume instead. (3) Two vnode records are defined (op->file[]) for the vnode(s) involved in most operations. The vnode record (struct afs_vnode_param) contains: - The vnode pointer. - The fid of the vnode to be included in the parameters or that was returned in the reply (eg. FS.MakeDir). - The status and callback information that may be returned in the reply about the vnode. - Callback break and data version tracking for detecting simultaneous third-parth changes. (4) Pointers to dentries to be updated with new inodes. (5) An operations table pointer. The table includes pointers to functions for issuing AFS and YFS-variant RPCs, handling the success and abort of an operation and handling post-I/O-lock local editing of a directory. To make this work, the following function restructuring is made: (A) The rotation loop that issues calls to fileservers that can be found in each function that wants to issue an RPC (such as afs_mkdir()) is extracted out into common code, in a new file called fs_operation.c. (B) The rotation loops, such as the one in afs_mkdir(), are replaced with a much smaller piece of code that allocates an operation, sets the parameters and then calls out to the common code to do the actual work. (C) The code for handling the success and failure of an operation are moved into operation functions (as (5) above) and these are called from the core code at appropriate times. (D) The pseudo inode getting stuff used by the dynamic root code is moved over into dynroot.c. (E) struct afs_iget_data is absorbed into the operation struct and afs_iget() expects to be given an op pointer and a vnode record. (F) Point (E) doesn't work for the root dir of a volume, but we know the FID in advance (it's always vnode 1, unique 1), so a separate inode getter, afs_root_iget(), is provided to special-case that. (G) The inode status init/update functions now also take an op and a vnode record. (H) The RPC marshalling functions now, for the most part, just take an afs_operation struct as their only argument. All the data they need is held there. The result delivery functions write their answers there as well. (I) The call is attached to the operation and then the operation core does the waiting. And then the new operation code is, for the moment, made to just initialise the operation, get the appropriate vnode I/O locks and do the same rotation loop as before. This lays the foundation for the following changes in the future: (*) Overhauling the rotation (again). (*) Support for asynchronous I/O, where the fileserver rotation must be done asynchronously also. Signed-off-by: David Howells

afs: Remove the error argument from afs_protocol_error()

2020-05-31T14:19:52Z

Remove the error argument from afs_protocol_error() as it's always -EBADMSG. Signed-off-by: David Howells

afs: Actively poll fileservers to maintain NAT or firewall openings

2020-05-31T14:19:51Z

When an AFS client accesses a file, it receives a limited-duration callback promise that the server will notify it if another client changes a file. This callback duration can be a few hours in length. If a client mounts a volume and then an application prevents it from being unmounted, say by chdir'ing into it, but then does nothing for some time, the rxrpc_peer record will expire and rxrpc-level keepalive will cease. If there is NAT or a firewall between the client and the server, the route back for the server may close after a comparatively short duration, meaning that attempts by the server to notify the client may then bounce. The client, however, may (so far as it knows) still have a valid unexpired promise and will then rely on its cached data and will not see changes made on the server by a third party until it incidentally rechecks the status or the promise needs renewal. To deal with this, the client needs to regularly probe the server. This has two effects: firstly, it keeps a route open back for the server, and secondly, it causes the server to disgorge any notifications that got queued up because they couldn't be sent. Fix this by adding a mechanism to emit regular probes. Two levels of probing are made available: Under normal circumstances the 'slow' queue will be used for a fileserver - this just probes the preferred address once every 5 mins or so; however, if server fails to respond to any probes, the server will shift to the 'fast' queue from which all its interfaces will be probed every 30s. When it finally responds, the record will switch back to the slow queue. Further notes: (1) Probing is now no longer driven from the fileserver rotation algorithm. (2) Probes are dispatched to all interfaces on a fileserver when that an afs_server object is set up to record it. (3) The afs_server object is removed from the probe queues when we start to probe it. afs_is_probing_server() returns true if it's not listed - ie. it's undergoing probing. (4) The afs_server object is added back on to the probe queue when the final outstanding probe completes, but the probed_at time is set when we're about to launch a probe so that it's not dependent on the probe duration. (5) The timer and the work item added for this must be handed a count on net->servers_outstanding, which they hand on or release. This makes sure that network namespace cleanup waits for them. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Dave Botsch Signed-off-by: David Howells

afs: Split the usage count on struct afs_server

2020-05-31T14:19:51Z

Split the usage count on the afs_server struct to have an active count that registers who's actually using it separately from the reference count on the object. This allows a future patch to dispatch polling probes without advancing the "unuse" time into the future each time we emit a probe, which would otherwise prevent unused server records from expiring. Included in this: (1) The latter part of afs_destroy_server() in which the RCU destruction of afs_server objects is invoked and the outstanding server count is decremented is split out into __afs_put_server(). (2) afs_put_server() now calls __afs_put_server() rather then setting the management timer. (3) The calls begun by afs_fs_give_up_all_callbacks() and afs_fs_get_capabilities() can now take a ref on the server record, so afs_destroy_server() can just drop its ref and needn't wait for the completion of these calls. They'll put the ref when they're done. (4) Because of (3), afs_fs_probe_done() no longer needs to wake up afs_destroy_server() with server->probe_outstanding. (5) afs_gc_servers can be simplified. It only needs to check if server->active is 0 rather than playing games with the refcount. (6) afs_manage_servers() can propose a server for gc if usage == 0 rather than if ref == 1. The gc is effected by (5). Signed-off-by: David Howells

afs: Fix some tracing details

2020-03-13T23:04:34Z

Fix a couple of tracelines to indicate the usage count after the atomic op, not the usage count before it to be consistent with other afs and rxrpc trace lines. Change the wording of the afs_call_trace_work trace ID label from "WORK" to "QUEUE" to reflect the fact that it's queueing work, not doing work. Fixes: 341f741f04be ("afs: Refcount the afs_call struct") Signed-off-by: David Howells

afs: Fix use-after-loss-of-ref

2020-01-14T17:40:06Z

afs_lookup() has a tracepoint to indicate the outcome of d_splice_alias(), passing it the inode to retrieve the fid from. However, the function gave up its ref on that inode when it called d_splice_alias(), which may have failed and dropped the inode. Fix this by caching the fid. Fixes: 80548b03991f ("afs: Add more tracepoints") Reported-by: Al Viro Signed-off-by: David Howells Signed-off-by: Linus Torvalds

Merge tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2019-07-11T03:55:33Z

Pull afs updates from David Howells: "A set of minor changes for AFS: - Remove an unnecessary check in afs_unlink() - Add a tracepoint for tracking callback management - Add a tracepoint for afs_server object usage - Use struct_size() - Add mappings for AFS UAE abort codes to Linux error codes, using symbolic names rather than hex numbers in the .c file" * tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Add support for the UAE error table fs/afs: use struct_size() in kzalloc() afs: Trace afs_server usage afs: Add some callback management tracepoints afs: afs_unlink() doesn't need to check dentry->d_inode

afs: Trace afs_server usage

2019-06-20T17:12:17Z

Add a tracepoint (afs_server) to track the afs_server object usage count. Signed-off-by: David Howells