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2024-06-16afs: Don't cross .backup mountpoint from backup volumeMarc Dionne1-0/+5
commit 29be9100aca2915fab54b5693309bc42956542e5 upstream. Don't cross a mountpoint that explicitly specifies a backup volume (target is <vol>.backup) when starting from a backup volume. It it not uncommon to mount a volume's backup directly in the volume itself. This can cause tools that are not paying attention to get into a loop mounting the volume onto itself as they attempt to traverse the tree, leading to a variety of problems. This doesn't prevent the general case of loops in a sequence of mountpoints, but addresses a common special case in the same way as other afs clients. Reported-by: Jan Henrik Sylvester <jan.henrik.sylvester@uni-hamburg.de> Link: http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/768760.1716567475@warthog.procyon.org.uk Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-27afs: Revert "afs: Hide silly-rename files from userspace"David Howells1-10/+0
[ Upstream commit 0aec3847d044273733285dcff90afda89ad461d2 ] This reverts commit 57e9d49c54528c49b8bffe6d99d782ea051ea534. This undoes the hiding of .__afsXXXX silly-rename files. The problem with hiding them is that rm can't then manually delete them. This also reverts commit 5f7a07646655fb4108da527565dcdc80124b14c4 ("afs: Fix endless loop in directory parsing") as that's a bugfix for the above. Fixes: 57e9d49c5452 ("afs: Hide silly-rename files from userspace") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://lists.infradead.org/pipermail/linux-afs/2024-February/008102.html Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/3085695.1710328121@warthog.procyon.org.uk Reviewed-by: Jeffrey E Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-06afs: Fix endless loop in directory parsingDavid Howells1-1/+3
[ Upstream commit 5f7a07646655fb4108da527565dcdc80124b14c4 ] If a directory has a block with only ".__afsXXXX" files in it (from uncompleted silly-rename), these .__afsXXXX files are skipped but without advancing the file position in the dir_context. This leads to afs_dir_iterate() repeating the block again and again. Fix this by making the code that skips the .__afsXXXX file also manually advance the file position. The symptoms are a soft lookup: watchdog: BUG: soft lockup - CPU#3 stuck for 52s! [check:5737] ... RIP: 0010:afs_dir_iterate_block+0x39/0x1fd ... ? watchdog_timer_fn+0x1a6/0x213 ... ? asm_sysvec_apic_timer_interrupt+0x16/0x20 ? afs_dir_iterate_block+0x39/0x1fd afs_dir_iterate+0x10a/0x148 afs_readdir+0x30/0x4a iterate_dir+0x93/0xd3 __do_sys_getdents64+0x6b/0xd4 This is almost certainly the actual fix for: https://bugzilla.kernel.org/show_bug.cgi?id=218496 Fixes: 57e9d49c5452 ("afs: Hide silly-rename files from userspace") Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/786185.1708694102@warthog.procyon.org.uk Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01afs: Increase buffer size in afs_update_volume_status()Daniil Dulov1-2/+2
[ Upstream commit 6ea38e2aeb72349cad50e38899b0ba6fbcb2af3d ] The max length of volume->vid value is 20 characters. So increase idbuf[] size up to 24 to avoid overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. [DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()] Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20240211150442.3416-1-d.dulov@aladdin.ru/ # v1 Link: https://lore.kernel.org/r/20240212083347.10742-1-d.dulov@aladdin.ru/ # v2 Link: https://lore.kernel.org/r/20240219143906.138346-3-dhowells@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*()Oleg Nesterov1-3/+4
[ Upstream commit 1702e0654ca9a7bcd7c7619c8a5004db58945b71 ] David Howells says: (5) afs_find_server(). There could be a lot of servers in the list and each server can have multiple addresses, so I think this would be better with an exclusive second pass. The server list isn't likely to change all that often, but when it does change, there's a good chance several servers are going to be added/removed one after the other. Further, this is only going to be used for incoming cache management/callback requests from the server, which hopefully aren't going to happen too often - but it is remotely drivable. (6) afs_find_server_by_uuid(). Similarly to (5), there could be a lot of servers to search through, but they are in a tree not a flat list, so it should be faster to process. Again, it's not likely to change that often and, again, when it does change it's likely to involve multiple changes. This can be driven remotely by an incoming cache management request but is mostly going to be driven by setting up or reconfiguring a volume's server list - something that also isn't likely to happen often. Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock() never takes the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> 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/20231130115614.GA21581@redhat.com/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23afs: fix the usage of read_seqbegin_or_lock() in afs_lookup_volume_rcu()Oleg Nesterov1-1/+2
[ Upstream commit 4121b4337146b64560d1e46ebec77196d9287802 ] David Howells says: (2) afs_lookup_volume_rcu(). There can be a lot of volumes known by a system. A thousand would require a 10-step walk and this is drivable by remote operation, so I think this should probably take a lock on the second pass too. Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock() never takes the lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> 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/20231130115606.GA21571@redhat.com/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23afs: Hide silly-rename files from userspaceDavid Howells1-0/+8
[ Upstream commit 57e9d49c54528c49b8bffe6d99d782ea051ea534 ] There appears to be a race between silly-rename files being created/removed and various userspace tools iterating over the contents of a directory, leading to such errors as: find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory tar: ./include/linux/greybus/.__afs3C95: File removed before we read it when building a kernel. Fix afs_readdir() so that it doesn't return .__afsXXXX silly-rename files to userspace. This doesn't stop them being looked up directly by name as we need to be able to look them up from within the kernel as part of the silly-rename algorithm. Fixes: 79ddbfa500b3 ("afs: Implement sillyrename for unlink and rename") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-05afs: Fix overwriting of result of DNS queryDavid Howells1-2/+4
[ Upstream commit a9e01ac8c5ff32669119c40dfdc9e80eb0b7d7aa ] In afs_update_cell(), ret is the result of the DNS lookup and the errors are to be handled by a switch - however, the value gets clobbered in between by setting it to -ENOMEM in case afs_alloc_vlserver_list() fails. Fix this by moving the setting of -ENOMEM into the error handling for OOM failure. Further, only do it if we don't have an alternative error to return. Found by Linux Verification Center (linuxtesting.org) with SVACE. Based on a patch from Anastasia Belova [1]. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Anastasia Belova <abelova@astralinux.ru> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: lvc-project@linuxtesting.org Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.ru/ [1] Link: https://lore.kernel.org/r/1700862.1703168632@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-05afs: Fix dynamic root lookup DNS checkDavid Howells1-2/+16
[ Upstream commit 74cef6872ceaefb5b6c5c60641371ea28702d358 ] In the afs dynamic root directory, the ->lookup() function does a DNS check on the cell being asked for and if the DNS upcall reports an error it will report an error back to userspace (typically ENOENT). However, if a failed DNS upcall returns a new-style result, it will return a valid result, with the status field set appropriately to indicate the type of failure - and in that case, dns_query() doesn't return an error and we let stat() complete with no error - which can cause confusion in userspace as subsequent calls that trigger d_automount then fail with ENOENT. Fix this by checking the status result from a valid dns_query() and returning an error if it indicates a failure. Fixes: bbb4c4323a4d ("dns: Allow the dns resolver to retrieve a server set") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-05afs: Fix the dynamic root's d_delete to always delete unused dentriesDavid Howells1-12/+1
[ Upstream commit 71f8b55bc30e82d6355e07811213d847981a32e2 ] Fix the afs dynamic root's d_delete function to always delete unused dentries rather than only deleting them if they're positive. With things as they stand upstream, negative dentries stemming from failed DNS lookups stick around preventing retries. Fixes: 66c7e1d319a5 ("afs: Split the dynroot stuff out and give it its own ops tables") Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-20afs: Fix refcount underflow from error handling raceDavid Howells1-1/+1
[ Upstream commit 52bf9f6c09fca8c74388cd41cc24e5d1bff812a9 ] If an AFS cell that has an unreachable (eg. ENETUNREACH) server listed (VL server or fileserver), an asynchronous probe to one of its addresses may fail immediately because sendmsg() returns an error. When this happens, a refcount underflow can happen if certain events hit a very small window. The way this occurs is: (1) There are two levels of "call" object, the afs_call and the rxrpc_call. Each of them can be transitioned to a "completed" state in the event of success or failure. (2) Asynchronous afs_calls are self-referential whilst they are active to prevent them from evaporating when they're not being processed. This reference is disposed of when the afs_call is completed. Note that an afs_call may only be completed once; once completed completing it again will do nothing. (3) When a call transmission is made, the app-side rxrpc code queues a Tx buffer for the rxrpc I/O thread to transmit. The I/O thread invokes sendmsg() to transmit it - and in the case of failure, it transitions the rxrpc_call to the completed state. (4) When an rxrpc_call is completed, the app layer is notified. In this case, the app is kafs and it schedules a work item to process events pertaining to an afs_call. (5) When the afs_call event processor is run, it goes down through the RPC-specific handler to afs_extract_data() to retrieve data from rxrpc - and, in this case, it picks up the error from the rxrpc_call and returns it. The error is then propagated to the afs_call and that is completed too. At this point the self-reference is released. (6) If the rxrpc I/O thread manages to complete the rxrpc_call within the window between rxrpc_send_data() queuing the request packet and checking for call completion on the way out, then rxrpc_kernel_send_data() will return the error from sendmsg() to the app. (7) Then afs_make_call() will see an error and will jump to the error handling path which will attempt to clean up the afs_call. (8) The problem comes when the error handling path in afs_make_call() tries to unconditionally drop an async afs_call's self-reference. This self-reference, however, may already have been dropped by afs_extract_data() completing the afs_call (9) The refcount underflows when we return to afs_do_probe_vlserver() and that tries to drop its reference on the afs_call. Fix this by making afs_make_call() attempt to complete the afs_call rather than unconditionally putting it. That way, if afs_extract_data() manages to complete the call first, afs_make_call() won't do anything. The bug can be forced by making do_udp_sendmsg() return -ENETUNREACH and sticking an msleep() in rxrpc_send_data() after the 'success:' label to widen the race window. The error message looks something like: refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 720 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 ... RIP: 0010:refcount_warn_saturate+0xba/0x110 ... afs_put_call+0x1dc/0x1f0 [kafs] afs_fs_get_capabilities+0x8b/0xe0 [kafs] afs_fs_probe_fileserver+0x188/0x1e0 [kafs] afs_lookup_server+0x3bf/0x3f0 [kafs] afs_alloc_server_list+0x130/0x2e0 [kafs] afs_create_volume+0x162/0x400 [kafs] afs_get_tree+0x266/0x410 [kafs] vfs_get_tree+0x25/0xc0 fc_mount+0xe/0x40 afs_d_automount+0x1b3/0x390 [kafs] __traverse_mounts+0x8f/0x210 step_into+0x340/0x760 path_openat+0x13a/0x1260 do_filp_open+0xaf/0x160 do_sys_openat2+0xaf/0x170 or something like: refcount_t: underflow; use-after-free. ... RIP: 0010:refcount_warn_saturate+0x99/0xda ... afs_put_call+0x4a/0x175 afs_send_vl_probes+0x108/0x172 afs_select_vlserver+0xd6/0x311 afs_do_cell_detect_alias+0x5e/0x1e9 afs_cell_detect_alias+0x44/0x92 afs_validate_fc+0x9d/0x134 afs_get_tree+0x20/0x2e6 vfs_get_tree+0x1d/0xc9 fc_mount+0xe/0x33 afs_d_automount+0x48/0x9d __traverse_mounts+0xe0/0x166 step_into+0x140/0x274 open_last_lookups+0x1c1/0x1df path_openat+0x138/0x1c3 do_filp_open+0x55/0xb4 do_sys_openat2+0x6c/0xb6 Fixes: 34fa47612bfe ("afs: Fix race in async call refcounting") Reported-by: Bill MacAllister <bill@ca-zephyr.org> Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1052304 Suggested-by: Jeffrey E Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/2633992.1702073229@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08afs: Fix file locking on R/O volumes to operate in local modeDavid Howells1-0/+2
[ Upstream commit b590eb41be766c5a63acc7e8896a042f7a4e8293 ] AFS doesn't really do locking on R/O volumes as fileservers don't maintain state with each other and thus a lock on a R/O volume file on one fileserver will not be be visible to someone looking at the same file on another fileserver. Further, the server may return an error if you try it. Fix this by doing what other AFS clients do and handle filelocking on R/O volume files entirely within the client and don't touch the server. Fixes: 6c6c1d63c243 ("afs: Provide mount-time configurable byte-range file locking emulation") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08afs: Return ENOENT if no cell DNS record can be foundDavid Howells1-0/+10
[ Upstream commit 0167236e7d66c5e1e85d902a6abc2529b7544539 ] Make AFS return error ENOENT if no cell SRV or AFSDB DNS record (or cellservdb config file record) can be found rather than returning EDESTADDRREQ. Also add cell name lookup info to the cursor dump. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08afs: Make error on cell lookup failure consistent with OpenAFSDavid Howells1-2/+2
[ Upstream commit 2a4ca1b4b77850544408595e2433f5d7811a9daa ] When kafs tries to look up a cell in the DNS or the local config, it will translate a lookup failure into EDESTADDRREQ whereas OpenAFS translates it into ENOENT. Applications such as West expect the latter behaviour and fail if they see the former. This can be seen by trying to mount an unknown cell: # mount -t afs %example.com:cell.root /mnt mount: /mnt: mount(2) system call failed: Destination address required. Fixes: 4d673da14533 ("afs: Support the AFS dynamic root") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08afs: Fix afs_server_list to be cleaned up with RCUDavid Howells2-1/+2
[ Upstream commit e6bace7313d61e31f2b16fa3d774fd8cb3cb869e ] afs_server_list is accessed with the rcu_read_lock() held from volume->servers, so it needs to be cleaned up correctly. Fix this by using kfree_rcu() instead of kfree(). Fixes: 8a070a964877 ("afs: Detect cell aliases 1 - Cells with root volumes") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-21afs: Fix vlserver probe RTT handlingDavid Howells1-2/+2
[ Upstream commit ba00b190670809c1a89326d80de96d714f6004f2 ] In the same spirit as commit ca57f02295f1 ("afs: Fix fileserver probe RTT handling"), don't rule out using a vlserver just because there haven't been enough packets yet to calculate a real rtt. Always set the server's probe rtt from the estimate provided by rxrpc_kernel_get_srtt, which is capped at 1 second. This could lead to EDESTADDRREQ errors when accessing a cell for the first time, even though the vl servers are known and have responded to a probe. Fixes: 1d4adfaf6574 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2023-June/006746.html Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-14afs: Fix setting of mtime when creating a file/dir/symlinkDavid Howells1-0/+3
[ Upstream commit a27648c742104a833a01c54becc24429898d85bf ] kafs incorrectly passes a zero mtime (ie. 1st Jan 1970) to the server when creating a file, dir or symlink because the mtime recorded in the afs_operation struct gets passed to the server by the marshalling routines, but the afs_mkdir(), afs_create() and afs_symlink() functions don't set it. This gets masked if a file or directory is subsequently modified. Fix this by filling in op->mtime before calling the create op. Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17afs: Fix updating of i_size with dv jump from serverMarc Dionne1-0/+1
[ Upstream commit d7f74e9a917503ee78f2b603a456d7227cf38919 ] If the data version returned from the server is larger than expected, the local data is invalidated, but we may still want to note the remote file size. Since we're setting change_size, we have to also set data_changed for the i_size to get updated. Fixes: 3f4aa9818163 ("afs: Fix EOF corruption") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14afs: Fix lost servers_outstanding countDavid Howells1-1/+4
[ Upstream commit 36f82c93ee0bd88f1c95a52537906b8178b537f1 ] The afs_fs_probe_dispatcher() work function is passed a count on net->servers_outstanding when it is scheduled (which may come via its timer). This is passed back to the work_item, passed to the timer or dropped at the end of the dispatcher function. But, at the top of the dispatcher function, there are two checks which skip the rest of the function: if the network namespace is being destroyed or if there are no fileservers to probe. These two return paths, however, do not drop the count passed to the dispatcher, and so, sometimes, the destruction of a network namespace, such as induced by rmmod of the kafs module, may get stuck in afs_purge_servers(), waiting for net->servers_outstanding to become zero. Fix this by adding the missing decrements in afs_fs_probe_dispatcher(). Fixes: f6cbb368bcb0 ("afs: Actively poll fileservers to maintain NAT or firewall openings") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/167164544917.2072364.3759519569649459359.stgit@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08afs: Fix fileserver probe RTT handlingDavid Howells1-2/+2
[ Upstream commit ca57f02295f188d6c65ec02202402979880fa6d8 ] The fileserver probing code attempts to work out the best fileserver to use for a volume by retrieving the RTT calculated by AF_RXRPC for the probe call sent to each server and comparing them. Sometimes, however, no RTT estimate is available and rxrpc_kernel_get_srtt() returns false, leading good fileservers to be given an RTT of UINT_MAX and thus causing the rotation algorithm to ignore them. Fix afs_select_fileserver() to ignore rxrpc_kernel_get_srtt()'s return value and just take the estimated RTT it provides - which will be capped at 1 second. Fixes: 1d4adfaf6574 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/166965503999.3392585.13954054113218099395.stgit@warthog.procyon.org.uk/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-23afs: Return -EAGAIN, not -EREMOTEIO, when a file already lockedDavid Howells1-0/+1
[ Upstream commit 0066f1b0e27556381402db3ff31f85d2a2265858 ] When trying to get a file lock on an AFS file, the server may return UAEAGAIN to indicate that the lock is already held. This is currently translated by the default path to -EREMOTEIO. Translate it instead to -EAGAIN so that we know we can retry it. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey E Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/166075761334.3533338.2591992675160918098.stgit@warthog.procyon.org.uk/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15afs: Use the operation issue time instead of the reply time for callbacksDavid Howells5-12/+5
[ Upstream commit 7903192c4b4a82d792cb0dc5e2779a2efe60d45b ] rxrpc and kafs between them try to use the receive timestamp on the first data packet (ie. the one with sequence number 1) as a base from which to calculate the time at which callback promise and lock expiration occurs. However, we don't know how long it took for the server to send us the reply from it having completed the basic part of the operation - it might then, for instance, have to send a bunch of a callback breaks, depending on the particular operation. Fix this by using the time at which the operation is issued on the client as a base instead. That should never be longer than the server's idea of the expiry time. Fixes: 781070551c26 ("afs: Fix calculation of callback expiry time") Fixes: 2070a3e44962 ("rxrpc: Allow the reply time to be obtained on a client call") Suggested-by: Jeffrey E Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-29afs: Fix dynamic root getattrDavid Howells1-1/+2
[ Upstream commit cb78d1b5efffe4cf97e16766329dd7358aed3deb ] The recent patch to make afs_getattr consult the server didn't account for the pseudo-inodes employed by the dynamic root-type afs superblock not having a volume or a server to access, and thus an oops occurs if such a directory is stat'd. Fix this by checking to see if the vnode->volume pointer actually points anywhere before following it in afs_getattr(). This can be tested by stat'ing a directory in /afs. It may be sufficient just to do "ls /afs" and the oops looks something like: BUG: kernel NULL pointer dereference, address: 0000000000000020 ... RIP: 0010:afs_getattr+0x8b/0x14b ... Call Trace: <TASK> vfs_statx+0x79/0xf5 vfs_fstatat+0x49/0x62 Fixes: 2aeb8c86d499 ("afs: Fix afs_getattr() to refetch file status if callback break occurred") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/165408450783.1031787.7941404776393751186.stgit@warthog.procyon.org.uk/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14afs: Fix infinite loop found by xfstest generic/676David Howells1-1/+4
[ Upstream commit 17eabd42560f4636648ad65ba5b20228071e2363 ] In AFS, a directory is handled as a file that the client downloads and parses locally for the purposes of performing lookup and getdents operations. The in-kernel afs filesystem has a number of functions that do this. A directory file is arranged as a series of 2K blocks divided into 32-byte slots, where a directory entry occupies one or more slots, plus each block starts with one or more metadata blocks. When parsing a block, if the last slots are occupied by a dirent that occupies more than a single slot and the file position points at a slot that's not the initial one, the logic in afs_dir_iterate_block() that skips over it won't advance the file pointer to the end of it. This will cause an infinite loop in getdents() as it will keep retrying that block and failing to advance beyond the final entry. Fix this by advancing the file pointer if the next entry will be beyond it when we skip a block. This was found by the generic/676 xfstest but can also be triggered with something like: ~/xfstests-dev/src/t_readdir_3 /xfstest.test/z 4000 1 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lore.kernel.org/r/165391973497.110268.2939296942213894166.stgit@warthog.procyon.org.uk/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09rxrpc, afs: Fix selection of abort codesDavid Howells1-3/+5
[ Upstream commit de696c4784f0706884458893c5a6c39b3a3ff65c ] The RX_USER_ABORT code should really only be used to indicate that the user of the rxrpc service (ie. userspace) implicitly caused a call to be aborted - for instance if the AF_RXRPC socket is closed whilst the call was in progress. (The user may also explicitly abort a call and specify the abort code to use). Change some of the points of generation to use other abort codes instead: (1) Abort the call with RXGEN_SS_UNMARSHAL or RXGEN_CC_UNMARSHAL if we see ENOMEM and EFAULT during received data delivery and abort with RX_CALL_DEAD in the default case. (2) Abort with RXGEN_SS_MARSHAL if we get ENOMEM whilst trying to send a reply. (3) Abort with RX_CALL_DEAD if we stop hearing from the peer if we had heard from the peer and abort with RX_CALL_TIMEOUT if we hadn't. (4) Abort with RX_CALL_DEAD if we try to disconnect a call that's not completed successfully or been aborted. Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25afs: Fix afs_getattr() to refetch file status if callback break occurredDavid Howells1-1/+13
[ Upstream commit 2aeb8c86d49967552394d5e723f87454cb53f501 ] 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: 08e0e7c82eea ("[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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30afs: Fix updating of i_blocks on file/dir extensionDavid Howells4-13/+13
[ Upstream commit 9d37e1cab2a9d2cee2737973fa455e6f89eee46a ] When an afs file or directory is modified locally such that the total file size is extended, i_blocks needs to be recalculated too. Fix this by making afs_write_end() and afs_edit_dir_add() call afs_set_i_size() rather than setting inode->i_size directly as that also recalculates inode->i_blocks. This can be tested by creating and writing into directories and files and then examining them with du. Without this change, directories show a 4 blocks (they start out at 2048 bytes) and files show 0 blocks; with this change, they should show a number of blocks proportional to the file size rounded up to 1024. Fixes: 31143d5d515e ("AFS: implement basic file write support") Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/163113612442.352844.11162345591911691150.stgit@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30afs: Fix incorrect triggering of sillyrename on 3rd-party invalidationDavid Howells1-39/+7
[ Upstream commit 63d49d843ef5fffeea069e0ffdfbd2bf40ba01c6 ] The AFS filesystem is currently triggering the silly-rename cleanup from afs_d_revalidate() when it sees that a dentry has been changed by a third party[1]. It should not be doing this as the cleanup includes deleting the silly-rename target file on iput. Fix this by removing the places in the d_revalidate handling that validate anything other than the directory and the dirent. It probably should not be looking to validate the target inode of the dentry also. This includes removing the point in afs_d_revalidate() where the inode that a dentry used to point to was marked as being deleted (AFS_VNODE_DELETED). We don't know it got deleted. It could have been renamed or it could have hard links remaining. This was reproduced by cloning a git repo onto an afs volume on one machine, switching to another machine and doing "git status", then switching back to the first and doing "git status". The second status would show weird output due to ".git/index" getting deleted by the above mentioned mechanism. A simpler way to do it is to do: machine 1: touch a machine 2: touch b; mv -f b a machine 1: stat a on an afs volume. The bug shows up as the stat failing with ENOENT and the file server log showing that machine 1 deleted "a". Fixes: 79ddbfa500b3 ("afs: Implement sillyrename for unlink and rename") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Markus Suvanto <markus.suvanto@gmail.com> cc: linux-afs@lists.infradead.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=214217#c4 [1] Link: https://lore.kernel.org/r/163111668100.283156.3851669884664475428.stgit@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28afs: Fix tracepoint string placement with built-in AFSDavid Howells1-18/+7
[ Upstream commit 6c881ca0b3040f3e724eae513117ba4ddef86057 ] To quote Alexey[1]: I was adding custom tracepoint to the kernel, grabbed full F34 kernel .config, disabled modules and booted whole shebang as VM kernel. Then did perf record -a -e ... It crashed: general protection fault, probably for non-canonical address 0x435f5346592e4243: 0000 [#1] SMP PTI CPU: 1 PID: 842 Comm: cat Not tainted 5.12.6+ #26 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 RIP: 0010:t_show+0x22/0xd0 Then reproducer was narrowed to # cat /sys/kernel/tracing/printk_formats Original F34 kernel with modules didn't crash. So I started to disable options and after disabling AFS everything started working again. The root cause is that AFS was placing char arrays content into a section full of _pointers_ to strings with predictable consequences. Non canonical address 435f5346592e4243 is "CB.YFS_" which came from CM_NAME macro. Steps to reproduce: CONFIG_AFS=y CONFIG_TRACING=y # cat /sys/kernel/tracing/printk_formats Fix this by the following means: (1) Add enum->string translation tables in the event header with the AFS and YFS cache/callback manager operations listed by RPC operation ID. (2) Modify the afs_cb_call tracepoint to print the string from the translation table rather than using the string at the afs_call name pointer. (3) Switch translation table depending on the service we're being accessed as (AFS or YFS) in the tracepoint print clause. Will this cause problems to userspace utilities? Note that the symbolic representation of the YFS service ID isn't available to this header, so I've put it in as a number. I'm not sure if this is the best way to do this. (4) Remove the name wrangling (CM_NAME) macro and put the names directly into the afs_call_type structs in cmservice.c. Fixes: 8e8d7f13b6d5a9 ("afs: Add some tracepoints") Reported-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: Andrew Morton <akpm@linux-foundation.org> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/YLAXfvZ+rObEOdc%2F@localhost.localdomain/ [1] Link: https://lore.kernel.org/r/643721.1623754699@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/162430903582.2896199.6098150063997983353.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/162609463957.3133237.15916579353149746363.stgit@warthog.procyon.org.uk/ # v1 (repost) Link: https://lore.kernel.org/r/162610726860.3408253.445207609466288531.stgit@warthog.procyon.org.uk/ # v2 Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23afs: Fix an IS_ERR() vs NULL checkDan Carpenter1-2/+2
[ Upstream commit a33d62662d275cee22888fa7760fe09d5b9cd1f9 ] The proc_symlink() function returns NULL on error, it doesn't return error pointers. Fixes: 5b86d4ff5dce ("afs: Implement network namespacing") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/YLjMRKX40pTrJvgf@mwanda/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03afs: Fix the nlink handling of dir-over-dir renameDavid Howells1-1/+3
commit f610a5a29c3cfb7d37bdfa4ef52f72ea51f24a76 upstream. Fix rename of one directory over another such that the nlink on the deleted directory is cleared to 0 rather than being decremented to 1. This was causing the generic/035 xfstest to fail. Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") 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/162194384460.3999479.7605572278074191079.stgit@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14afs: Fix speculative status fetchesDavid Howells6-2/+23
[ Upstream commit 22650f148126571be1098d34160eb4931fc77241 ] The generic/464 xfstest causes kAFS to emit occasional warnings of the form: kAFS: vnode modified {100055:8a} 30->31 YFS.StoreData64 (c=6015) This indicates that the data version received back from the server did not match the expected value (the DV should be incremented monotonically for each individual modification op committed to a vnode). What is happening is that a lookup call is doing a bulk status fetch speculatively on a bunch of vnodes in a directory besides getting the status of the vnode it's actually interested in. This is racing with a StoreData operation (though it could also occur with, say, a MakeDir op). On the client, a modification operation locks the vnode, but the bulk status fetch only locks the parent directory, so no ordering is imposed there (thereby avoiding an avenue to deadlock). On the server, the StoreData op handler doesn't lock the vnode until it's received all the request data, and downgrades the lock after committing the data until it has finished sending change notifications to other clients - which allows the status fetch to occur before it has finished. This means that: - a status fetch can access the target vnode either side of the exclusive section of the modification - the status fetch could start before the modification, yet finish after, and vice-versa. - the status fetch and the modification RPCs can complete in either order. - the status fetch can return either the before or the after DV from the modification. - the status fetch might regress the locally cached DV. Some of these are handled by the previous fix[1], but that's not sufficient because it checks the DV it received against the DV it cached at the start of the op, but the DV might've been updated in the meantime by a locally generated modification op. Fix this by the following means: (1) Keep track of when we're performing a modification operation on a vnode. This is done by marking vnode parameters with a 'modification' note that causes the AFS_VNODE_MODIFYING flag to be set on the vnode for the duration. (2) Alter the speculation race detection to ignore speculative status fetches if either the vnode is marked as being modified or the data version number is not what we expected. Note that whilst the "vnode modified" warning does get recovered from as it causes the client to refetch the status at the next opportunity, it will also invalidate the pagecache, so changes might get lost. Fixes: a9e5c87ca744 ("afs: Fix speculative status fetch going out of order wrt to modifications") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-and-reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/160605082531.252452.14708077925602709042.stgit@warthog.procyon.org.uk/ [1] Link: https://lore.kernel.org/linux-fsdevel/161961335926.39335.2552653972195467566.stgit@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14afs: Fix updating of i_mode due to 3rd party changeDavid Howells1-3/+3
[ Upstream commit 6e1eb04a87f954eb06a89ee6034c166351dfff6e ] Fix afs_apply_status() to mask off the irrelevant bits from status->mode when OR'ing them into i_mode. This can happen when a 3rd party chmod occurs. Also fix afs_inode_init_from_status() to mask off the mode bits when initialising i_mode. Fixes: 260a980317da ("[AFS]: Add "directory write" support.") Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25afs: Stop listxattr() from listing "afs.*" attributesDavid Howells6-28/+0
commit a7889c6320b9200e3fe415238f546db677310fa9 upstream. afs_listxattr() lists all the available special afs xattrs (i.e. those in the "afs.*" space), no matter what type of server we're dealing with. But OpenAFS servers, for example, cannot deal with some of the extra-capable attributes that AuriStor (YFS) servers provide. Unfortunately, the presence of the afs.yfs.* attributes causes errors[1] for anything that tries to read them if the server is of the wrong type. Fix the problem by removing afs_listxattr() so that none of the special xattrs are listed (AFS doesn't support xattrs). It does mean, however, that getfattr won't list them, though they can still be accessed with getxattr() and setxattr(). This can be tested with something like: getfattr -d -m ".*" /afs/example.com/path/to/file With this change, none of the afs.* attributes should be visible. Changes: ver #2: - Hide all of the afs.* xattrs, not just the ACL ones. Fixes: ae46578b963f ("afs: Get YFS ACLs and information through xattrs") Reported-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003502.html [1] Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003567.html # v1 Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003573.html # v2 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25afs: Fix accessing YFS xattrs on a non-YFS serverDavid Howells2-3/+12
commit 64fcbb6158ecc684d84c64424830a9c37c77c5b9 upstream. If someone attempts to access YFS-related xattrs (e.g. afs.yfs.acl) on a file on a non-YFS AFS server (such as OpenAFS), then the kernel will jump to a NULL function pointer because the afs_fetch_acl_operation descriptor doesn't point to a function for issuing an operation on a non-YFS server[1]. Fix this by making afs_wait_for_operation() check that the issue_afs_rpc method is set before jumping to it and setting -ENOTSUPP if not. This fix also covers other potential operations that also only exist on YFS servers. afs_xattr_get/set_yfs() then need to translate -ENOTSUPP to -ENODATA as the former error is internal to the kernel. The bug shows up as an oops like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [...] Call Trace: afs_wait_for_operation+0x83/0x1b0 [kafs] afs_xattr_get_yfs+0xe6/0x270 [kafs] __vfs_getxattr+0x59/0x80 vfs_getxattr+0x11c/0x140 getxattr+0x181/0x250 ? __check_object_size+0x13f/0x150 ? __fput+0x16d/0x250 __x64_sys_fgetxattr+0x64/0xb0 do_syscall_64+0x49/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fb120a9defe This was triggered with "cp -a" which attempts to copy xattrs, including afs ones, but is easier to reproduce with getfattr, e.g.: getfattr -d -m ".*" /afs/openafs.org/ Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Reported-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003498.html [1] Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003566.html # v1 Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003572.html # v2 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10rxrpc: Fix deadlock around release of dst cached on udp tunnelDavid Howells1-3/+3
[ Upstream commit 5399d52233c47905bbf97dcbaa2d7a9cc31670ba ] AF_RXRPC sockets use UDP ports in encap mode. This causes socket and dst from an incoming packet to get stolen and attached to the UDP socket from whence it is leaked when that socket is closed. When a network namespace is removed, the wait for dst records to be cleaned up happens before the cleanup of the rxrpc and UDP socket, meaning that the wait never finishes. Fix this by moving the rxrpc (and, by dependence, the afs) private per-network namespace registrations to the device group rather than subsys group. This allows cached rxrpc local endpoints to be cleared and their UDP sockets closed before we try waiting for the dst records. The symptom is that lines looking like the following: unregister_netdevice: waiting for lo to become free get emitted at regular intervals after running something like the referenced syzbot test. Thanks to Vadim for tracking this down and work out the fix. Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com Reported-by: Vadim Fedorenko <vfedorenko@novek.ru> Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vadim Fedorenko <vfedorenko@novek.ru> Link: https://lore.kernel.org/r/161196443016.3868642.5577440140646403533.stgit@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-09afs: Fix memory leak when mounting with multiple source parametersDavid Howells1-0/+3
There's a memory leak in afs_parse_source() whereby multiple source= parameters overwrite fc->source in the fs_context struct without freeing the previously recorded source. Fix this by only permitting a single source parameter and rejecting with an error all subsequent ones. This was caught by syzbot with the kernel memory leak detector, showing something like the following trace: unreferenced object 0xffff888114375440 (size 32): comm "repro", pid 5168, jiffies 4294923723 (age 569.948s) backtrace: slab_post_alloc_hook+0x42/0x79 __kmalloc_track_caller+0x125/0x16a kmemdup_nul+0x24/0x3c vfs_parse_fs_string+0x5a/0xa1 generic_parse_monolithic+0x9d/0xc5 do_new_mount+0x10d/0x15a do_mount+0x5f/0x8e __do_sys_mount+0xff/0x127 do_syscall_64+0x2d/0x3a entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 13fcc6837049 ("afs: Add fs_context support") Reported-by: syzbot+86dc6632faaca40133ab@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-22afs: Fix speculative status fetch going out of order wrt to modificationsDavid Howells3-0/+10
When doing a lookup in a directory, the afs filesystem uses a bulk status fetch to speculatively retrieve the statuses of up to 48 other vnodes found in the same directory and it will then either update extant inodes or create new ones - effectively doing 'lookup ahead'. To avoid the possibility of deadlocking itself, however, the filesystem doesn't lock all of those inodes; rather just the directory inode is locked (by the VFS). When the operation completes, afs_inode_init_from_status() or afs_apply_status() is called, depending on whether the inode already exists, to commit the new status. A case exists, however, where the speculative status fetch operation may straddle a modification operation on one of those vnodes. What can then happen is that the speculative bulk status RPC retrieves the old status, and whilst that is happening, the modification happens - which returns an updated status, then the modification status is committed, then we attempt to commit the speculative status. This results in something like the following being seen in dmesg: kAFS: vnode modified {100058:861} 8->9 YFS.InlineBulkStatus showing that for vnode 861 on volume 100058, we saw YFS.InlineBulkStatus say that the vnode had data version 8 when we'd already recorded version 9 due to a local modification. This was causing the cache to be invalidated for that vnode when it shouldn't have been. If it happens on a data file, this might lead to local changes being lost. Fix this by ignoring speculative status updates if the data version doesn't match the expected value. Note that it is possible to get a DV regression if a volume gets restored from a backup - but we should get a callback break in such a case that should trigger a recheck anyway. It might be worth checking the volume creation time in the volsync info and, if a change is observed in that (as would happen on a restore), invalidate all caches associated with the volume. Fixes: 5cf9dd55a0ec ("afs: Prospectively look up extra files when doing a single lookup") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14afs: Fix afs_write_end() when called with copied == 0 [ver #3]David Howells1-1/+4
When afs_write_end() is called with copied == 0, it tries to set the dirty region, but there's no way to actually encode a 0-length region in the encoding in page->private. "0,0", for example, indicates a 1-byte region at offset 0. The maths miscalculates this and sets it incorrectly. Fix it to just do nothing but unlock and put the page in this case. We don't actually need to mark the page dirty as nothing presumably changed. Fixes: 65dd2d6072d3 ("afs: Alter dirty range encoding in page->private") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-03afs: Fix incorrect freeing of the ACL passed to the YFS ACL store opDavid Howells1-6/+1
The cleanup for the yfs_store_opaque_acl2_operation calls the wrong function to destroy the ACL content buffer. It's an afs_acl struct, not a yfs_acl struct - and the free function for latter may pass invalid pointers to kfree(). Fix this by using the afs_acl_put() function. The yfs_acl_put() function is then no longer used and can be removed. general protection fault, probably for non-canonical address 0x7ebde00000000: 0000 [#1] SMP PTI ... RIP: 0010:compound_head+0x0/0x11 ... Call Trace: virt_to_cache+0x8/0x51 kfree+0x5d/0x79 yfs_free_opaque_acl+0x16/0x29 afs_put_operation+0x60/0x114 __vfs_setxattr+0x67/0x72 __vfs_setxattr_noperm+0x66/0xe9 vfs_setxattr+0x67/0xce setxattr+0x14e/0x184 __do_sys_fsetxattr+0x66/0x8f do_syscall_64+0x2d/0x3a entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-03afs: Fix warning due to unadvanced marshalling pointerDavid Howells1-0/+1
When using the afs.yfs.acl xattr to change an AuriStor ACL, a warning can be generated when the request is marshalled because the buffer pointer isn't increased after adding the last element, thereby triggering the check at the end if the ACL wasn't empty. This just causes something like the following warning, but doesn't stop the call from happening successfully: kAFS: YFS.StoreOpaqueACL2: Request buffer underflow (36<108) Fix this simply by increasing the count prior to the check. Fixes: f5e4546347bc ("afs: Implement YFS ACL setting") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-29afs: Fix dirty-region encoding on ppc32 with 64K pagesDavid Howells2-9/+20
The dirty region bounds stored in page->private on an afs page are 15 bits on a 32-bit box and can, at most, represent a range of up to 32K within a 32K page with a resolution of 1 byte. This is a problem for powerpc32 with 64K pages enabled. Further, transparent huge pages may get up to 2M, which will be a problem for the afs filesystem on all 32-bit arches in the future. Fix this by decreasing the resolution. For the moment, a 64K page will have a resolution determined from PAGE_SIZE. In the future, the page will need to be passed in to the helper functions so that the page size can be assessed and the resolution determined dynamically. Note that this might not be the ideal way to handle this, since it may allow some leakage of undirtied zero bytes to the server's copy in the case of a 3rd-party conflict. Fixing that would require a separately allocated record and is a more complicated fix. Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-29afs: Fix afs_invalidatepage to adjust the dirty regionDavid Howells3-12/+76
Fix afs_invalidatepage() to adjust the dirty region recorded in page->private when truncating a page. If the dirty region is entirely removed, then the private data is cleared and the page dirty state is cleared. Without this, if the page is truncated and then expanded again by truncate, zeros from the expanded, but no-longer dirty region may get written back to the server if the page gets laundered due to a conflicting 3rd-party write. It mustn't, however, shorten the dirty region of the page if that page is still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is stored in page->private to record this. Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29afs: Alter dirty range encoding in page->privateDavid Howells2-4/+4
Currently, page->private on an afs page is used to store the range of dirtied data within the page, where the range includes the lower bound, but excludes the upper bound (e.g. 0-1 is a range covering a single byte). This, however, requires a superfluous bit for the last-byte bound so that on a 4KiB page, it can say 0-4096 to indicate the whole page, the idea being that having both numbers the same would indicate an empty range. This is unnecessary as the PG_private bit is clear if it's an empty range (as is PG_dirty). Alter the way the dirty range is encoded in page->private such that the upper bound is reduced by 1 (e.g. 0-0 is then specified the same single byte range mentioned above). Applying this to both bounds frees up two bits, one of which can be used in a future commit. This allows the afs filesystem to be compiled on ppc32 with 64K pages; without this, the following warnings are seen: ../fs/afs/internal.h: In function 'afs_page_dirty_to': ../fs/afs/internal.h:881:15: warning: right shift count >= width of type [-Wshift-count-overflow] 881 | return (priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK; | ^~ ../fs/afs/internal.h: In function 'afs_page_dirty': ../fs/afs/internal.h:886:28: warning: left shift count >= width of type [-Wshift-count-overflow] 886 | return ((unsigned long)to << __AFS_PAGE_PRIV_SHIFT) | from; | ^~ Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29afs: Wrap page->private manipulations in inline functionsDavid Howells2-18/+41
The afs filesystem uses page->private to store the dirty range within a page such that in the event of a conflicting 3rd-party write to the server, we write back just the bits that got changed locally. However, there are a couple of problems with this: (1) I need a bit to note if the page might be mapped so that partial invalidation doesn't shrink the range. (2) There aren't necessarily sufficient bits to store the entire range of data altered (say it's a 32-bit system with 64KiB pages or transparent huge pages are in use). So wrap the accesses in inline functions so that future commits can change how this works. Also move them out of the tracing header into the in-directory header. There's not really any need for them to be in the tracing header. Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29afs: Fix where page->private is set during writeDavid Howells1-15/+26
In afs, page->private is set to indicate the dirty region of a page. This is done in afs_write_begin(), but that can't take account of whether the copy into the page actually worked. Fix this by moving the change of page->private into afs_write_end(). Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-29afs: Fix page leak on afs_write_begin() failureDavid Howells1-12/+11
Fix the leak of the target page in afs_write_begin() when it fails. Fixes: 15b4650e55e0 ("afs: convert to new aops") Signed-off-by: David Howells <dhowells@redhat.com> cc: Nick Piggin <npiggin@gmail.com>
2020-10-29afs: Fix to take ref on page when PG_private is setDavid Howells4-26/+18
Fix afs to take a ref on a page when it sets PG_private on it and to drop the ref when removing the flag. Note that in afs_write_begin(), a lot of the time, PG_private is already set on a page to which we're going to add some data. In such a case, we leave the bit set and mustn't increment the page count. As suggested by Matthew Wilcox, use attach/detach_page_private() where possible. Fixes: 31143d5d515e ("AFS: implement basic file write support") Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-28afs: Fix afs_launder_page to not clear PG_writebackDavid Howells2-4/+7
Fix afs_launder_page() to not clear PG_writeback on the page it is laundering as the flag isn't set in this case. Fixes: 4343d00872e1 ("afs: Get rid of the afs_writeback record") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-28afs: Fix a use after free in afs_xattr_get_acl()Dan Carpenter1-1/+1
The "op" pointer is freed earlier when we call afs_put_operation(). Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Colin Ian King <colin.king@canonical.com>