summaryrefslogtreecommitdiff
path: root/fs/afs/server.c
AgeCommit message (Collapse)AuthorFilesLines
2022-11-30afs: Fix server->active leak in afs_put_serverMarc Dionne1-1/+1
The atomic_read was accidentally replaced with atomic_inc_return, which prevents the server from getting cleaned up and causes rmmod to hang with a warning: Can't purge s=00000001 Fixes: 2757a4dc1849 ("afs: Fix access after dec in put functions") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20221130174053.2665818-1-marc.dionne@auristor.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-08-02afs: Fix access after dec in put functionsDavid Howells1-9/+13
Reference-putting functions should not access the object being put after decrementing the refcount unless they reduce the refcount to zero. Fix a couple of instances of this in afs by copying the information to be logged by tracepoint to local variables before doing the decrement. [Fixed a bit in afs_put_server() that I'd missed but Marc caught] Fixes: 341f741f04be ("afs: Refcount the afs_call struct") Fixes: 452181936931 ("afs: Trace afs_server usage") Fixes: 977e5f8ed0ab ("afs: Split the usage count on struct afs_server") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/165911278430.3745403.16526310736054780645.stgit@warthog.procyon.org.uk/ # v1
2022-08-02afs: Use refcount_t rather than atomic_tDavid Howells1-17/+23
Use refcount_t rather than atomic_t in afs to make use of the count checking facilities provided. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/165911277768.3745403.423349776836296452.stgit@warthog.procyon.org.uk/ # v1
2021-09-13afs: Fix mmap coherency vs 3rd-party changesDavid Howells1-0/+2
Fix the coherency management of mmap'd data such that 3rd-party changes become visible as soon as possible after the callback notification is delivered by the fileserver. This is done by the following means: (1) When we break a callback on a vnode specified by the CB.CallBack call from the server, we queue a work item (vnode->cb_work) to go and clobber all the PTEs mapping to that inode. This causes the CPU to trip through the ->map_pages() and ->page_mkwrite() handlers if userspace attempts to access the page(s) again. (Ideally, this would be done in the service handler for CB.CallBack, but the server is waiting for our reply before considering, and we have a list of vnodes, all of which need breaking - and the process of getting the mmap_lock and stripping the PTEs on all CPUs could be quite slow.) (2) Call afs_validate() from the ->map_pages() handler to check to see if the file has changed and to get a new callback promise from the server. Also handle the fileserver telling us that it's dropping all callbacks, possibly after it's been restarted by sending us a CB.InitCallBackState* call by the following means: (3) Maintain a per-cell list of afs files that are currently mmap'd (cell->fs_open_mmaps). (4) Add a work item to each server that is invoked if there are any open mmaps when CB.InitCallBackState happens. This work item goes through the aforementioned list and invokes the vnode->cb_work work item for each one that is currently using this server. This causes the PTEs to be cleared, causing ->map_pages() or ->page_mkwrite() to be called again, thereby calling afs_validate() again. I've chosen to simply strip the PTEs at the point of notification reception rather than invalidate all the pages as well because (a) it's faster, (b) we may get a notification for other reasons than the data being altered (in which case we don't want to clobber the pagecache) and (c) we need to ask the server to find out - and I don't want to wait for the reply before holding up userspace. This was tested using the attached test program: #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/mman.h> int main(int argc, char *argv[]) { size_t size = getpagesize(); unsigned char *p; bool mod = (argc == 3); int fd; if (argc != 2 && argc != 3) { fprintf(stderr, "Format: %s <file> [mod]\n", argv[0]); exit(2); } fd = open(argv[1], mod ? O_RDWR : O_RDONLY); if (fd < 0) { perror(argv[1]); exit(1); } p = mmap(NULL, size, mod ? PROT_READ|PROT_WRITE : PROT_READ, MAP_SHARED, fd, 0); if (p == MAP_FAILED) { perror("mmap"); exit(1); } for (;;) { if (mod) { p[0]++; msync(p, size, MS_ASYNC); fsync(fd); } printf("%02x", p[0]); fflush(stdout); sleep(1); } } It runs in two modes: in one mode, it mmaps a file, then sits in a loop reading the first byte, printing it and sleeping for a second; in the second mode it mmaps a file, then sits in a loop incrementing the first byte and flushing, then printing and sleeping. Two instances of this program can be run on different machines, one doing the reading and one doing the writing. The reader should see the changes made by the writer, but without this patch, they aren't because validity checking is being done lazily - only on entry to the filesystem. Testing the InitCallBackState change is more complicated. The server has to be taken offline, the saved callback state file removed and then the server restarted whilst the reading-mode program continues to run. The client machine then has to poke the server to trigger the InitCallBackState call. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163111668833.283156.382633263709075739.stgit@warthog.procyon.org.uk/
2020-10-16afs: Don't assert on unpurgeable server recordsDavid Howells1-1/+6
Don't give an assertion failure on unpurgeable afs_server records - which kills the thread - but rather emit a trace line when we are purging a record (which only happens during network namespace removal or rmmod) and print a notice of the problem. Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-20afs: Fix hang on rmmod due to outstanding timerDavid Howells1-1/+2
The fileserver probe timer, net->fs_probe_timer, isn't cancelled when the kafs module is being removed and so the count it holds on net->servers_outstanding doesn't get dropped.. This causes rmmod to wait forever. The hung process shows a stack like: afs_purge_servers+0x1b5/0x23c [kafs] afs_net_exit+0x44/0x6e [kafs] ops_exit_list+0x72/0x93 unregister_pernet_operations+0x14c/0x1ba unregister_pernet_subsys+0x1d/0x2a afs_exit+0x29/0x6f [kafs] __do_sys_delete_module.isra.0+0x1a2/0x24b do_syscall_64+0x51/0x95 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by: (1) Attempting to cancel the probe timer and, if successful, drop the count that the timer was holding. (2) Make the timer function just drop the count and not schedule the prober if the afs portion of net namespace is being destroyed. Also, whilst we're at it, make the following changes: (3) Initialise net->servers_outstanding to 1 and decrement it before waiting on it so that it doesn't generate wake up events by being decremented to 0 until we're cleaning up. (4) Switch the atomic_dec() on ->servers_outstanding for ->fs_timer in afs_purge_servers() to use the helper function for that. Fixes: f6cbb368bcb0 ("afs: Actively poll fileservers to maintain NAT or firewall openings") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04afs: Don't use probe running state to make decisions outside probe codeDavid Howells1-0/+1
Don't use the running state for fileserver probes to make decisions about which server to use as the state is cleared at the start of a probe and also intermediate values might be misleading. Instead, add a separate 'latest known' rtt in the afs_server struct and a flag to indicate if the server is known to be responding and update these as and when we know what to change them to. Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-04afs: Fix the by-UUID server tree to allow servers with the same UUIDDavid Howells1-8/+48
Whilst it shouldn't happen, it is possible for multiple fileservers to share a UUID, particularly if an entire cell has been duplicated, UUIDs and all. In such a case, it's not necessarily possible to map the effect of the CB.InitCallBackState3 incoming RPC to a specific server unambiguously by UUID and thus to a specific cell. Indeed, there's a problem whereby multiple server records may need to occupy the same spot in the rb_tree rooted in the afs_net struct. Fix this by allowing servers to form a list, with the head of the list in the tree. When the front entry in the list is removed, the second in the list just replaces it. afs_init_callback_state() then just goes down the line, poking each server in the list. This means that some servers will be unnecessarily poked, unfortunately. An alternative would be to route by call parameters. Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
2020-06-04afs: Reorganise volume and server trees to be rooted on the cellDavid Howells1-6/+7
Reorganise afs_volume objects such that they're in a tree keyed on volume ID, rooted at on an afs_cell object rather than being in multiple trees, each of which is rooted on an afs_server object. afs_server structs become per-cell and acquire a pointer to the cell. The process of breaking a callback then starts with finding the server by its network address, following that to the cell and then looking up each volume ID in the volume tree. This is simpler than the afs_vol_interest/afs_cb_interest N:M mapping web and allows those structs and the code for maintaining them to be simplified or removed. It does make a couple of things a bit more tricky, though: (1) Operations now start with a volume, not a server, so there can be more than one answer as to whether or not the server we'll end up using supports the FS.InlineBulkStatus RPC. (2) CB RPC operations that specify the server UUID. There's still a tree of servers by UUID on the afs_net struct, but the UUIDs in it aren't guaranteed unique. Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-04afs: Build an abstraction around an "operation" conceptDavid Howells1-16/+21
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 <dhowells@redhat.com>
2020-05-31afs: Rename struct afs_fs_cursor to afs_operationDavid Howells1-4/+4
As a prelude to implementing asynchronous fileserver operations in the afs filesystem, rename struct afs_fs_cursor to afs_operation. This struct is going to form the core of the operation management and is going to acquire more members in later. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31afs: Make callback processing more efficient.David Howells1-2/+2
afs_vol_interest objects represent the volume IDs currently being accessed from a fileserver. These hold lists of afs_cb_interest objects that repesent the superblocks using that volume ID on that server. When a callback notification from the server telling of a modification by another client arrives, the volume ID specified in the notification is looked up in the server's afs_vol_interest list. Through the afs_cb_interest list, the relevant superblocks can be iterated over and the specific inode looked up and marked in each one. Make the following efficiency improvements: (1) Hold rcu_read_lock() over the entire processing rather than locking it each time. (2) Do all the callbacks for each vid together rather than individually. Each volume then only needs to be looked up once. (3) afs_vol_interest objects are now stored in an rb_tree rather than a flat list to reduce the lookup step count. (4) afs_vol_interest lookup is now done with RCU, but because it's in an rb_tree which may rotate under us, a seqlock is used so that if it changes during the walk, we repeat the walk with a lock held. With this and the preceding patch which adds RCU-based lookups in the inode cache, target volumes/vnodes can be taken without the need to take any locks, except on the target itself. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31afs: Actively poll fileservers to maintain NAT or firewall openingsDavid Howells1-11/+8
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 <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31afs: Split the usage count on struct afs_serverDavid Howells1-51/+100
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 <dhowells@redhat.com>
2020-05-31afs: Use the serverUnique field in the UVLDB record to reduce rpc opsDavid Howells1-12/+14
The U-version VLDB volume record retrieved by the VL.GetEntryByNameU rpc op carries a change counter (the serverUnique field) for each fileserver listed in the record as backing that volume. This is incremented whenever the registration details for a fileserver change (such as its address list). Note that the same value will be seen in all UVLDB records that refer to that fileserver. This should be checked before calling the VL server to re-query the address list for a fileserver. If it's the same, there's no point doing the query. Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-24afs: Make record checking use TASK_UNINTERRUPTIBLE when appropriateDavid Howells1-5/+2
When an operation is meant to be done uninterruptibly (such as FS.StoreData), we should not be allowing volume and server record checking to be interrupted. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com>
2019-12-09afs: Fix afs_find_server lookups for ipv4 peersMarc Dionne1-13/+8
afs_find_server tries to find a server that has an address that matches the transport address of an rxrpc peer. The code assumes that the transport address is always ipv6, with ipv4 represented as ipv4 mapped addresses, but that's not the case. If the transport family is AF_INET, srx->transport.sin6.sin6_addr.s6_addr32[] will be beyond the actual ipv4 address and will always be 0, and all ipv4 addresses will be seen as matching. As a result, the first ipv4 address seen on any server will be considered a match, and the server returned may be the wrong one. One of the consequences is that callbacks received over ipv4 will only be correctly applied for the server that happens to have the first ipv4 address on the fs_addresses4 list. Callbacks over ipv4 from all other servers are dropped, causing the client to serve stale data. This is fixed by looking at the transport family, and comparing ipv4 addresses based on a sockaddr_in structure rather than a sockaddr_in6. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Remove set but not used variable 'ret'zhengbin1-2/+1
Fixes gcc '-Wunused-but-set-variable' warning: fs/afs/server.c: In function afs_install_server: fs/afs/server.c:157:6: warning: variable ret set but not used [-Wunused-but-set-variable] It is not used since commit d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-07-11Merge tag 'afs-next-20190628' of ↵Linus Torvalds1-7/+32
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs 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
2019-06-20afs: Trace afs_server usageDavid Howells1-7/+32
Add a tracepoint (afs_server) to track the afs_server object usage count. Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-16afs: Make some RPC operations non-interruptibleDavid Howells1-0/+11
Make certain RPC operations non-interruptible, including: (*) Set attributes (*) Store data We don't want to get interrupted during a flush on close, flush on unlock, writeback or an inode update, leaving us in a state where we still need to do the writeback or update. (*) Extend lock (*) Release lock We don't want to get lock extension interrupted as the file locks on the server are time-limited. Interruption during lock release is less of an issue since the lock is time-limited, but it's better to complete the release to avoid a several-minute wait to recover it. *Setting* the lock isn't a problem if it's interrupted since we can just return to the user and tell them they were interrupted - at which point they can elect to retry. (*) Silly unlink We want to remove silly unlink files if we can, rather than leaving them for the salvager to clear up. Note that whilst these calls are no longer interruptible, they do have timeouts on them, so if the server stops responding the call will fail with something like ETIME or ECONNRESET. Without this, the following: kAFS: Unexpected error from FS.StoreData -512 appears in dmesg when a pending store data gets interrupted and some processes may just hang. Additionally, make the code that checks/updates the server record ignore failure due to interruption if the main call is uninterruptible and if the server has an address list. The next op will check it again since the expiration time on the old list has past. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Jonathan Billings <jsbillings@jsbillings.org> Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16afs: Fix error propagation from server record check/updateDavid Howells1-3/+3
afs_check/update_server_record() should be setting fc->error rather than fc->ac.error as they're called from within the cursor iteration function. afs_fs_cursor::error is where the error code of the attempt to call the operation on multiple servers is integrated and is the final result, whereas afs_addr_cursor::error is used to hold the error from individual iterations of the call loop. (Note there's also an afs_vl_cursor which also wraps afs_addr_cursor for accessing VL servers rather than file servers). Fix this by setting fc->error in the afs_check/update_server_record() so that any error incurred whilst talking to the VL server correctly propagates to the final result. This results in: kAFS: Unexpected error from FS.StoreData -512 being seen, even though the store-data op is non-interruptible. The error is actually coming from the server record update getting interrupted. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13afs: Fix in-progess ops to ignore server-level callback invalidationDavid Howells1-1/+0
The in-kernel afs filesystem client counts the number of server-level callback invalidation events (CB.InitCallBackState* RPC operations) that it receives from the server. This is stored in cb_s_break in various structures, including afs_server and afs_vnode. If an inode is examined by afs_validate(), say, the afs_server copy is compared, along with other break counters, to those in afs_vnode, and if one or more of the counters do not match, it is considered that the server's callback promise is broken. At points where this happens, AFS_VNODE_CB_PROMISED is cleared to indicate that the status must be refetched from the server. afs_validate() issues an FS.FetchStatus operation to get updated metadata - and based on the updated data_version may invalidate the pagecache too. However, the break counters are also used to determine whether to note a new callback in the vnode (which would set the AFS_VNODE_CB_PROMISED flag) and whether to cache the permit data included in the YFSFetchStatus record by the server. The problem comes when the server sends us a CB.InitCallBackState op. The first such instance doesn't cause cb_s_break to be incremented, but rather causes AFS_SERVER_FL_NEW to be cleared - but thereafter, say some hours after last use and all the volumes have been automatically unmounted and the server has forgotten about the client[*], this *will* likely cause an increment. [*] There are other circumstances too, such as the server restarting or needing to make space in its callback table. Note that the server won't send us a CB.InitCallBackState op until we talk to it again. So what happens is: (1) A mount for a new volume is attempted, a inode is created for the root vnode and vnode->cb_s_break and AFS_VNODE_CB_PROMISED aren't set immediately, as we don't have a nominated server to talk to yet - and we may iterate through a few to find one. (2) Before the operation happens, afs_fetch_status(), say, notes in the cursor (fc.cb_break) the break counter sum from the vnode, volume and server counters, but the server->cb_s_break is currently 0. (3) We send FS.FetchStatus to the server. The server sends us back CB.InitCallBackState. We increment server->cb_s_break. (4) Our FS.FetchStatus completes. The reply includes a callback record. (5) xdr_decode_AFSCallBack()/xdr_decode_YFSCallBack() check to see whether the callback promise was broken by checking the break counter sum from step (2) against the current sum. This fails because of step (3), so we don't set the callback record and, importantly, don't set AFS_VNODE_CB_PROMISED on the vnode. This does not preclude the syscall from progressing, and we don't loop here rechecking the status, but rather assume it's good enough for one round only and will need to be rechecked next time. (6) afs_validate() it triggered on the vnode, probably called from d_revalidate() checking the parent directory. (7) afs_validate() notes that AFS_VNODE_CB_PROMISED isn't set, so doesn't update vnode->cb_s_break and assumes the vnode to be invalid. (8) afs_validate() needs to calls afs_fetch_status(). Go back to step (2) and repeat, every time the vnode is validated. This primarily affects volume root dir vnodes. Everything subsequent to those inherit an already incremented cb_s_break upon mounting. The issue is that we assume that the callback record and the cached permit information in a reply from the server can't be trusted after getting a server break - but this is wrong since the server makes sure things are done in the right order, holding up our ops if necessary[*]. [*] There is an extremely unlikely scenario where a reply from before the CB.InitCallBackState could get its delivery deferred till after - at which point we think we have a promise when we don't. This, however, requires unlucky mass packet loss to one call. AFS_SERVER_FL_NEW tries to paper over the cracks for the initial mount from a server we've never contacted before, but this should be unnecessary. It's also further insulated from the problem on an initial mount by querying the server first with FS.GetCapabilities, which triggers the CB.InitCallBackState. Fix this by (1) Remove AFS_SERVER_FL_NEW. (2) In afs_calc_vnode_cb_break(), don't include cb_s_break in the calculation. (3) In afs_cb_is_broken(), don't include cb_s_break in the check. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24afs: Probe multiple fileservers simultaneouslyDavid Howells1-102/+7
Send probes to all the unprobed fileservers in a fileserver list on all addresses simultaneously in an attempt to find out the fastest route whilst not getting stuck for 20s on any server or address that we don't get a reply from. This alleviates the problem whereby attempting to access a new server can take a long time because the rotation algorithm ends up rotating through all servers and addresses until it finds one that responds. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24afs: Eliminate the address pointer from the address list cursorDavid Howells1-2/+0
Eliminate the address pointer from the address list cursor as it's redundant (ac->addrs[ac->index] can be used to find the same address) and address lists must be replaced rather than being rearranged, so is of limited value. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24afs: Implement YFS support in the fs clientDavid Howells1-0/+8
Implement support for talking to YFS-variant fileservers in the cache manager and the filesystem client. These implement upgraded services on the same port as their AFS services. YFS fileservers provide expanded capabilities over AFS. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24afs: Add a couple of tracepoints to log I/O errorsDavid Howells1-1/+1
Add a couple of tracepoints to log the production of I/O errors within the AFS filesystem. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24afs: Implement VL server rotationDavid Howells1-30/+12
Track VL servers as independent entities rather than lumping all their addresses together into one set and implement server-level rotation by: (1) Add the concept of a VL server list, where each server has its own separate address list. This code is similar to the FS server list. (2) Use the DNS resolver to retrieve a set of servers and their associated addresses, ports, preference and weight ratings. (3) In the case of a legacy DNS resolver or an address list given directly through /proc/net/afs/cells, create a list containing just a dummy server record and attach all the addresses to that. (4) Implement a simple rotation policy, for the moment ignoring the priorities and weights assigned to the servers. (5) Show the address list through /proc/net/afs/<cell>/vlservers. This also displays the source and status of the data as indicated by the upcall. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-15afs: Fix clearance of replyDavid Howells1-2/+0
The recent patch to fix the afs_server struct leak didn't actually fix the bug, but rather fixed some of the symptoms. The problem is that an asynchronous call that holds a resource pointed to by call->reply[0] will find the pointer cleared in the call destructor, thereby preventing the resource from being cleaned up. In the case of the server record leak, the afs_fs_get_capabilities() function in devel code sets up a call with reply[0] pointing at the server record that should be altered when the result is obtained, but this was being cleared before the destructor was called, so the put in the destructor does nothing and the record is leaked. Commit f014ffb025c1 removed the additional ref obtained by afs_install_server(), but the removal of this ref is actually used by the garbage collector to mark a server record as being defunct after the record has expired through lack of use. The offending clearance of call->reply[0] upon completion in afs_process_async_call() has been there from the origin of the code, but none of the asynchronous calls actually use that pointer currently, so it should be safe to remove (note that synchronous calls don't involve this function). Fix this by the following means: (1) Revert commit f014ffb025c1. (2) Remove the clearance of reply[0] from afs_process_async_call(). Without this, afs_manage_servers() will suffer an assertion failure if it sees a server record that didn't get used because the usage count is not 1. Fixes: f014ffb025c1 ("afs: Fix afs_server struct leak") Fixes: 08e0e7c82eea ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.") Signed-off-by: David Howells <dhowells@redhat.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-12afs: Fix afs_server struct leakDavid Howells1-0/+2
Fix a leak of afs_server structs. The routine that installs them in the various lookup lists and trees gets a ref on leaving the function, whether it added the server or a server already exists. It shouldn't increment the refcount if it added the server. The effect of this that "rmmod kafs" will hang waiting for the leaked server to become unused. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-15afs: Optimise callback breaking by not repeating volume lookupDavid Howells1-1/+1
At the moment, afs_break_callbacks calls afs_break_one_callback() for each separate FID it was given, and the latter looks up the volume individually for each one. However, this is inefficient if two or more FIDs have the same vid as we could reuse the volume. This is complicated by cell aliasing whereby we may have multiple cells sharing a volume and can therefore have multiple callback interests for any particular volume ID. At the moment afs_break_one_callback() scans the entire list of volumes we're getting from a server and breaks the appropriate callback in every matching volume, regardless of cell. This scan is done for every FID. Optimise callback breaking by the following means: (1) Sort the FID list by vid so that all FIDs belonging to the same volume are clumped together. This is done through the use of an indirection table as we cannot do an insertion sort on the afs_callback_break array as we decode FIDs into it as we subsequently also have to decode callback info into it that corresponds by array index only. We also don't really want to bubblesort afterwards if we can avoid it. (2) Sort the server->cb_interests array by vid so that all the matching volumes are grouped together. This permits the scan to stop after finding a record that has a higher vid. (3) When breaking FIDs, we try to keep server->cb_break_lock as long as possible, caching the start point in the array for that volume group as long as possible. It might make sense to add another layer in that list and have a refcounted volume ID anchor that has the matching interests attached to it rather than being in the list. This would allow the lock to be dropped without losing the cursor. Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14afs: Fix afs_find_server search loopMarc Dionne1-13/+0
The code that looks up servers by addresses makes the assumption that the list of addresses for a server is sorted. It exits the loop if it finds that the target address is larger than the current candidate. As the list is not currently sorted, this can lead to a failure to find a matching server, which can cause callbacks from that server to be ignored. Remove the early exit case so that the complete list is searched. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14afs: Fix giving up callbacks on server destructionDavid Howells1-3/+5
When a server record is destroyed, we want to send a message to the server telling it that we're giving up all the callbacks it has promised us. Apply two fixes to this: (1) Only send the FS.GiveUpAllCallBacks message if we actually got a callback from that server. We assume this to be the case if we performed at least one successful FS operation on that server. (2) Send it to the address last used for that server rather than always picking the first address in the list (which might be unreachable). Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-20afs: Fix server record deletionDavid Howells1-1/+8
AFS server records get removed from the net->fs_servers tree when they're deleted, but not from the net->fs_addresses{4,6} lists, which can lead to an oops in afs_find_server() when a server record has been removed, for instance during rmmod. Fix this by deleting the record from the by-address lists before posting it for RCU destruction. The reason this hasn't been noticed before is that the fileserver keeps probing the local cache manager, thereby keeping the service record alive, so the oops would only happen when a fileserver eventually gets bored and stops pinging or if the module gets rmmod'd and a call comes in from the fileserver during the window between the server records being destroyed and the socket being closed. The oops looks something like: BUG: unable to handle kernel NULL pointer dereference at 000000000000001c ... Workqueue: kafsd afs_process_async_call [kafs] RIP: 0010:afs_find_server+0x271/0x36f [kafs] ... Call Trace: afs_deliver_cb_init_call_back_state3+0x1f2/0x21f [kafs] afs_deliver_to_call+0x1ee/0x5e8 [kafs] afs_process_async_call+0x5b/0xd0 [kafs] process_one_work+0x2c2/0x504 worker_thread+0x1d4/0x2ac kthread+0x11f/0x127 ret_from_fork+0x24/0x30 Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-09afs: Fix checker warningsDavid Howells1-6/+8
Fix warnings raised by checker, including: (*) Warnings raised by unequal comparison for the purposes of sorting, where the endianness doesn't matter: fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer (*) afs_set_cb_interest() is not actually used and can be removed. (*) afs_cell_gc_delay() should be provided with a sysctl. (*) afs_cell_destroy() needs to use rcu_access_pointer() to read cell->vl_addrs. (*) afs_init_fs_cursor() should be static. (*) struct afs_vnode::permit_cache needs to be marked __rcu. (*) afs_server_rcu() needs to use rcu_access_pointer(). (*) afs_destroy_server() should use rcu_access_pointer() on server->addresses as the server object is no longer accessible. (*) afs_find_server() casts __be16/__be32 values to int in order to directly compare them for the purpose of finding a match in a list, but is should also annotate the cast with __force to avoid checker warnings. (*) afs_check_permit() accesses vnode->permit_cache outside of the RCU readlock, though it doesn't then access the value; the extraneous access is deleted. False positives: (*) Conditional locking around the code in xdr_decode_AFSFetchStatus. This can be dealt with in a separate patch. fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block (*) Incorrect handling of seq-retry lock context balance: fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different lock contexts for basic block fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block Errors: (*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go round again if it successfully found the workstation cell. (*) Fix UUID decode in afs_deliver_cb_probe_uuid(). (*) afs_cache_permit() has a missing rcu_read_unlock() before one of the jumps to the someone_else_changed_it label. Move the unlock to after the label. (*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when encoding to XDR. (*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl() when decoding from XDR. Signed-off-by: David Howells <dhowells@redhat.com>
2018-03-20sched/wait, fs/afs: Convert wait_on_atomic_t() usage to the new ↵Peter Zijlstra1-3/+3
wait_var_event() API The old wait_on_atomic_t() is going to get removed, use the more flexible wait_var_event() API instead. No change in functionality. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-13afs: Make use of the YFS service upgrade to fully support IPv6David Howells1-1/+4
YFS VL servers offer an upgraded Volume Location service that can return IPv6 addresses to fileservers and volume servers in addition to IPv4 addresses using the YFSVL.GetEndpoints operation which we should use if it's available. To this end: (1) Make rxrpc_kernel_recv_data() return the call's current service ID so that the caller can detect service upgrade and see what the service was upgraded to. (2) When we see a VL server address we haven't seen before, send a VL.GetCapabilities operation to it with the service upgrade bit set. If we get an upgrade to the YFS VL service, change the service ID in the address list for that address to use the upgraded service and set a flag to note that this appears to be a YFS-compatible server. (3) If, when a server's addresses are being looked up, we note that we previously detected a YFS-compatible server, then send the YFSVL.GetEndpoints operation rather than VL.GetAddrsU. (4) Build a fileserver address list from the reply of YFSVL.GetEndpoints, including both IPv4 and IPv6 addresses. Volume server addresses are discarded. (5) The address list is sorted by address and port now, instead of just address. This allows multiple servers on the same host sitting on different ports. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Overhaul volume and server record caching and fileserver rotationDavid Howells1-213/+537
The current code assumes that volumes and servers are per-cell and are never shared, but this is not enforced, and, indeed, public cells do exist that are aliases of each other. Further, an organisation can, say, set up a public cell and a private cell with overlapping, but not identical, sets of servers. The difference is purely in the database attached to the VL servers. The current code will malfunction if it sees a server in two cells as it assumes global address -> server record mappings and that each server is in just one cell. Further, each server may have multiple addresses - and may have addresses of different families (IPv4 and IPv6, say). To this end, the following structural changes are made: (1) Server record management is overhauled: (a) Server records are made independent of cell. The namespace keeps track of them, volume records have lists of them and each vnode has a server on which its callback interest currently resides. (b) The cell record no longer keeps a list of servers known to be in that cell. (c) The server records are now kept in a flat list because there's no single address to sort on. (d) Server records are now keyed by their UUID within the namespace. (e) The addresses for a server are obtained with the VL.GetAddrsU rather than with VL.GetEntryByName, using the server's UUID as a parameter. (f) Cached server records are garbage collected after a period of non-use and are counted out of existence before purging is allowed to complete. This protects the work functions against rmmod. (g) The servers list is now in /proc/fs/afs/servers. (2) Volume record management is overhauled: (a) An RCU-replaceable server list is introduced. This tracks both servers and their coresponding callback interests. (b) The superblock is now keyed on cell record and numeric volume ID. (c) The volume record is now tied to the superblock which mounts it, and is activated when mounted and deactivated when unmounted. This makes it easier to handle the cache cookie without causing a double-use in fscache. (d) The volume record is loaded from the VLDB using VL.GetEntryByNameU to get the server UUID list. (e) The volume name is updated if it is seen to have changed when the volume is updated (the update is keyed on the volume ID). (3) The vlocation record is got rid of and VLDB records are no longer cached. Sufficient information is stored in the volume record, though an update to a volume record is now no longer shared between related volumes (volumes come in bundles of three: R/W, R/O and backup). and the following procedural changes are made: (1) The fileserver cursor introduced previously is now fleshed out and used to iterate over fileservers and their addresses. (2) Volume status is checked during iteration, and the server list is replaced if a change is detected. (3) Server status is checked during iteration, and the address list is replaced if a change is detected. (4) The abort code is saved into the address list cursor and -ECONNABORTED returned in afs_make_call() if a remote abort happened rather than translating the abort into an error message. This allows actions to be taken depending on the abort code more easily. (a) If a VMOVED abort is seen then this is handled by rechecking the volume and restarting the iteration. (b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is handled by sleeping for a short period and retrying and/or trying other servers that might serve that volume. A message is also displayed once until the condition has cleared. (c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the moment. (d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to see if it has been deleted; if not, the fileserver is probably indicating that the volume couldn't be attached and needs salvaging. (e) If statfs() sees one of these aborts, it does not sleep, but rather returns an error, so as not to block the umount program. (5) The fileserver iteration functions in vnode.c are now merged into their callers and more heavily macroised around the cursor. vnode.c is removed. (6) Operations on a particular vnode are serialised on that vnode because the server will lock that vnode whilst it operates on it, so a second op sent will just have to wait. (7) Fileservers are probed with FS.GetCapabilities before being used. This is where service upgrade will be done. (8) A callback interest on a fileserver is set up before an FS operation is performed and passed through to afs_make_call() so that it can be set on the vnode if the operation returns a callback. The callback interest is passed through to afs_iget() also so that it can be set there too. In general, record updating is done on an as-needed basis when we try to access servers, volumes or vnodes rather than offloading it to work items and special threads. Notes: (1) Pre AFS-3.4 servers are no longer supported, though this can be added back if necessary (AFS-3.4 was released in 1998). (2) VBUSY is retried forever for the moment at intervals of 1s. (3) /proc/fs/afs/<cell>/servers no longer exists. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Add an address list conceptDavid Howells1-23/+47
Add an RCU replaceable address list structure to hold a list of server addresses. The list also holds the To this end: (1) A cell's VL server address list can be loaded directly via insmod or echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB or SRV records. (2) Anyone wanting to use a cell's VL server address must wait until the cell record comes online and has tried to obtain some addresses. (3) An FS server's address list, for the moment, has a single entry that is the key to the server list. This will change in the future when a server is instead keyed on its UUID and the VL.GetAddrsU operation is used. (4) An 'address cursor' concept is introduced to handle iteration through the address list. This is passed to the afs_make_call() as, in the future, stuff (such as abort code) that doesn't outlast the call will be returned in it. In the future, we might want to annotate the list with information about how each address fares. We might then want to propagate such annotations over address list replacement. Whilst we're at it, we allow IPv6 addresses to be specified in colon-delimited lists by enclosing them in square brackets. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Overhaul the callback handlingDavid Howells1-17/+4
Overhaul the AFS callback handling by the following means: (1) Don't give up callback promises on vnodes that we are no longer using, rather let them just expire on the server or let the server break them. This is actually more efficient for the server as the callback lookup is expensive if there are lots of extant callbacks. (2) Only give up the callback promises we have from a server when the server record is destroyed. Then we can just give up *all* the callback promises on it in one go. (3) Servers can end up being shared between cells if cells are aliased, so don't add all the vnodes being backed by a particular server into a big FID-indexed tree on that server as there may be duplicates. Instead have each volume instance (~= superblock) register an interest in a server as it starts to make use of it and use this to allow the processor for callbacks from the server to find the superblock and thence the inode corresponding to the FID being broken by means of ilookup_nowait(). (4) Rather than iterating over the entire callback list when a mass-break comes in from the server, maintain a counter of mass-breaks in afs_server (cb_seq) and make afs_validate() check it against the copy in afs_vnode. It would be nice not to have to take a read_lock whilst doing this, but that's tricky without using RCU. (5) Save a ref on the fileserver we're using for a call in the afs_call struct so that we can access its cb_s_break during call decoding. (6) Write-lock around callback and status storage in a vnode and read-lock around getattr so that we don't see the status mid-update. This has the following consequences: (1) Data invalidation isn't seen until someone calls afs_validate() on a vnode. Unfortunately, we need to use a key to query the server, but getting one from a background thread is tricky without caching loads of keys all over the place. (2) Mass invalidation isn't seen until someone calls afs_validate(). (3) Callback breaking is going to hit the inode_hash_lock quite a bit. Could this be replaced with rcu_read_lock() since inodes are destroyed under RCU conditions. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Allow IPv6 address specification of VL serversDavid Howells1-5/+0
Allow VL server specifications to be given IPv6 addresses as well as IPv4 addresses, for example as: echo add foo.org 1111:2222:3333:0:4444:5555:6666:7777 >/proc/fs/afs/cells Note that ':' is the expected separator for separating IPv4 addresses, but if a ',' is detected or no '.' is detected in the string, the delimiter is switched to ','. This also works with DNS AFSDB or SRV record strings fetched by upcall from userspace. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Keep and pass sockaddr_rxrpc addresses rather than in_addrDavid Howells1-15/+16
Keep and pass sockaddr_rxrpc addresses around rather than keeping and passing in_addr addresses to allow for the use of IPv6 and non-standard port numbers in future. This also allows the port and service_id fields to be removed from the afs_call struct. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Push the net ns pointer to more placesDavid Howells1-4/+3
Push the network namespace pointer to more places in AFS, including the afs_server structure (which doesn't hold a ref on the netns). In particular, afs_put_cell() now takes requires a net ns parameter so that it can safely alter the netns after decrementing the cell usage count - the cell will be deallocated by a background thread after being cached for a period, which means that it's not safe to access it after reducing its usage count. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Fix server reapingDavid Howells1-8/+51
Fix server reaping and make sure it's all done before we start trying to purge cells, given that servers currently pin cells. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13afs: Lay the groundwork for supporting network namespacesDavid Howells1-43/+39
Lay the groundwork for supporting network namespaces (netns) to the AFS filesystem by moving various global features to a network-namespace struct (afs_net) and providing an instance of this as a temporary global variable that everything uses via accessor functions for the moment. The following changes have been made: (1) Store the netns in the superblock info. This will be obtained from the mounter's nsproxy on a manual mount and inherited from the parent superblock on an automount. (2) The cell list is made per-netns. It can be viewed through /proc/net/afs/cells and also be modified by writing commands to that file. (3) The local workstation cell is set per-ns in /proc/net/afs/rootcell. This is unset by default. (4) The 'rootcell' module parameter, which sets a cell and VL server list modifies the init net namespace, thereby allowing an AFS root fs to be theoretically used. (5) The volume location lists and the file lock manager are made per-netns. (6) The AF_RXRPC socket and associated I/O bits are made per-ns. The various workqueues remain global for the moment. Changes still to be made: (1) /proc/fs/afs/ should be moved to /proc/net/afs/ and a symlink emplaced from the old name. (2) A per-netns subsys needs to be registered for AFS into which it can store its per-netns data. (3) Rather than the AF_RXRPC socket being opened on module init, it needs to be opened on the creation of a superblock in that netns. (4) The socket needs to be closed when the last superblock using it is destroyed and all outstanding client calls on it have been completed. This prevents a reference loop on the namespace. (5) It is possible that several namespaces will want to use AFS, in which case each one will need its own UDP port. These can either be set through /proc/net/afs/cm_port or the kernel can pick one at random. The init_ns gets 7001 by default. Other issues that need resolving: (1) The DNS keyring needs net-namespacing. (2) Where do upcalls go (eg. DNS request-key upcall)? (3) Need something like open_socket_in_file_ns() syscall so that AFS command line tools attempting to operate on an AFS file/volume have their RPC calls go to the right place. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Migrate vlocation fields to 64-bitTina Ruchandani1-3/+3
get_seconds() returns real wall-clock seconds. On 32-bit systems this value will overflow in year 2038 and beyond. This patch changes afs's vlocation record to use ktime_get_real_seconds() instead, for the fields time_of_death and update_at. Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30rxrpc: Provide a way for AFS to ask for the peer address of a callDavid Howells1-3/+8
Provide a function so that kernel users, such as AFS, can ask for the peer address of a call: void rxrpc_kernel_get_peer(struct rxrpc_call *call, struct sockaddr_rxrpc *_srx); In the future the kernel service won't get sk_buffs to look inside. Further, this allows us to hide any canonicalisation inside AF_RXRPC for when IPv6 support is added. Also propagate this through to afs_find_server() and issue a warning if we can't handle the address family yet. Signed-off-by: David Howells <dhowells@redhat.com>
2012-08-14workqueue: use mod_delayed_work() instead of cancel + queueTejun Heo1-8/+2
Convert delayed_work users doing cancel_delayed_work() followed by queue_delayed_work() to mod_delayed_work(). Most conversions are straight-forward. Ones worth mentioning are, * drivers/edac/edac_mc.c: edac_mc_workq_setup() converted to always use mod_delayed_work() and cancel loop in edac_mc_reset_delay_period() is dropped. * drivers/platform/x86/thinkpad_acpi.c: No need to remember whether watchdog is active or not. @fan_watchdog_active and related code dropped. * drivers/power/charger-manager.c: Seemingly a lot of delayed_work_pending() abuse going on here. [delayed_]work_pending() are unsynchronized and racy when used like this. I converted one instance in fullbatt_handler(). Please conver the rest so that it invokes workqueue APIs for the intended target state rather than trying to game work item pending state transitions. e.g. if timer should be modified - call mod_delayed_work(), canceled - call cancel_delayed_work[_sync](). * drivers/thermal/thermal_sys.c: thermal_zone_device_set_polling() simplified. Note that round_jiffies() calls in this function are meaningless. round_jiffies() work on absolute jiffies not delta delay used by delayed_work. v2: Tomi pointed out that __cancel_delayed_work() users can't be safely converted to mod_delayed_work(). They could be calling it from irq context and if that happens while delayed_work_timer_fn() is running, it could deadlock. __cancel_delayed_work() users are dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Anton Vorontsov <cbouatmailru@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Doug Thompson <dougthompson@xmission.com> Cc: David Airlie <airlied@linux.ie> Cc: Roland Dreier <roland@kernel.org> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <len.brown@intel.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Johannes Berg <johannes@sipsolutions.net>
2011-01-14afs: add afs_wq and use it instead of the system workqueueTejun Heo1-6/+7
flush_scheduled_work() is going away. afs needs to make sure all the works it has queued have finished before being unloaded and there can be arbitrary number of pending works. Add afs_wq and use it as the flush domain instead of the system workqueue. Also, convert cancel_delayed_work() + flush_scheduled_work() to cancel_delayed_work_sync() in afs_mntpt_kill_timer(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Cc: linux-afs@lists.infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>