kernel/fs/afs, branch linux-5.1.y

afs: Fix uninitialised spinlock afs_volume::cb_break_lock

2019-07-21T07:01:56Z

[ Upstream commit 90fa9b64523a645a97edc0bdcf2d74759957eeee ] Fix the cb_break_lock spinlock in afs_volume struct by initialising it when the volume record is allocated. Also rename the lock to cb_v_break_lock to distinguish it from the lock of the same name in the afs_server struct. Without this, the following trace may be observed when a volume-break callback is received: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 2 PID: 50 Comm: kworker/2:1 Not tainted 5.2.0-rc1-fscache+ #3045 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Workqueue: afs SRXAFSCB_CallBack Call Trace: dump_stack+0x67/0x8e register_lock_class+0x23b/0x421 ? check_usage_forwards+0x13c/0x13c __lock_acquire+0x89/0xf73 lock_acquire+0x13b/0x166 ? afs_break_callbacks+0x1b2/0x3dd _raw_write_lock+0x2c/0x36 ? afs_break_callbacks+0x1b2/0x3dd afs_break_callbacks+0x1b2/0x3dd ? trace_event_raw_event_afs_server+0x61/0xac SRXAFSCB_CallBack+0x11f/0x16c process_one_work+0x2c5/0x4ee ? worker_thread+0x234/0x2ac worker_thread+0x1d8/0x2ac ? cancel_delayed_work_sync+0xf/0xf kthread+0x11f/0x127 ? kthread_park+0x76/0x76 ret_from_fork+0x24/0x30 Fixes: 68251f0a6818 ("afs: Fix whole-volume callback handling") Signed-off-by: David Howells Signed-off-by: Sasha Levin

afs: Fix getting the afs.fid xattr

2019-05-31T13:43:13Z

[ Upstream commit a2f611a3dc317d8ea1c98ad6c54b911cf7f93193 ] The AFS3 FID is three 32-bit unsigned numbers and is represented as three up-to-8-hex-digit numbers separated by colons to the afs.fid xattr. However, with the advent of support for YFS, the FID is now a 64-bit volume number, a 96-bit vnode/inode number and a 32-bit uniquifier (as before). Whilst the sprintf in afs_xattr_get_fid() has been partially updated (it currently ignores the upper 32 bits of the 96-bit vnode number), the size of the stack-based buffer has not been increased to match, thereby allowing stack corruption to occur. Fix this by increasing the buffer size appropriately and conditionally including the upper part of the vnode number if it is non-zero. The latter requires the lower part to be zero-padded if the upper part is non-zero. Fixes: 3b6492df4153 ("afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS") Signed-off-by: David Howells Signed-off-by: Sasha Levin

afs: Fix in-progess ops to ignore server-level callback invalidation

2019-04-13T07:37:37Z

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

afs: Unlock pages for __pagevec_release()

2019-04-13T07:37:37Z

__pagevec_release() complains loudly if any page in the vector is still locked. The pages need to be locked for generic_error_remove_page(), but that function doesn't actually unlock them. Unlock the pages afterwards. Signed-off-by: Marc Dionne Signed-off-by: David Howells Tested-by: Jonathan Billings

afs: Differentiate abort due to unmarshalling from other errors

2019-04-13T07:37:37Z

Differentiate an abort due to an unmarshalling error from an abort due to other errors, such as ENETUNREACH. It doesn't make sense to set abort code RXGEN_*_UNMARSHAL in such a case, so use RX_USER_ABORT instead. Signed-off-by: David Howells

afs: Avoid section confusion in CM_NAME

2019-04-13T07:37:36Z

__tracepoint_str cannot be const because the tracepoint_str section is not read-only. Remove the stray const. Cc: dhowells@redhat.com Cc: viro@zeniv.linux.org.uk Signed-off-by: Andi Kleen

afs: avoid deprecated get_seconds()

2019-04-13T07:37:36Z

get_seconds() has a limited range on 32-bit architectures and is deprecated because of that. While AFS uses the same limits for its inode timestamps on the wire protocol, let's just use the simpler current_time() as we do for other file systems. This will still zero out the 'tv_nsec' field of the timestamps internally. Signed-off-by: Arnd Bergmann Signed-off-by: David Howells

afs: Check for rxrpc call completion in wait loop

2019-04-12T23:57:23Z

Check the state of the rxrpc call backing an afs call in each iteration of the call wait loop in case the rxrpc call has already been terminated at the rxrpc layer. Interrupt the wait loop and mark the afs call as complete if the rxrpc layer call is complete. There were cases where rxrpc errors were not passed up to afs, which could result in this loop waiting forever for an afs call to transition to AFS_CALL_COMPLETE while the rx call was already complete. Signed-off-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc: Make rxrpc_kernel_check_life() indicate if call completed

2019-04-12T23:57:23Z

Make rxrpc_kernel_check_life() pass back the life counter through the argument list and return true if the call has not yet completed. Suggested-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: David S. Miller

afs: Fix StoreData op marshalling

2019-03-28T15:54:20Z

The marshalling of AFS.StoreData, AFS.StoreData64 and YFS.StoreData64 calls generated by ->setattr() ops for the purpose of expanding a file is incorrect due to older documentation incorrectly describing the way the RPC 'FileLength' parameter is meant to work. The older documentation says that this is the length the file is meant to end up at the end of the operation; however, it was never implemented this way in any of the servers, but rather the file is truncated down to this before the write operation is effected, and never expanded to it (and, indeed, it was renamed to 'TruncPos' in 2014). Fix this by setting the position parameter to the new file length and doing a zero-lengh write there. The bug causes Xwayland to SIGBUS due to unexpected non-expansion of a file it then mmaps. This can be tested by giving the following test program a filename in an AFS directory: #include #include #include #include #include int main(int argc, char *argv[]) { char *p; int fd; if (argc != 2) { fprintf(stderr, "Format: test-trunc-mmap \n"); exit(2); } fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC); if (fd < 0) { perror(argv[1]); exit(1); } if (ftruncate(fd, 0x140008) == -1) { perror("ftruncate"); exit(1); } p = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (p == MAP_FAILED) { perror("mmap"); exit(1); } p[0] = 'a'; if (munmap(p, 4096) < 0) { perror("munmap"); exit(1); } if (close(fd) < 0) { perror("close"); exit(1); } exit(0); } Fixes: 31143d5d515e ("AFS: implement basic file write support") Reported-by: Jonathan Billings Tested-by: Jonathan Billings Signed-off-by: David Howells Signed-off-by: Linus Torvalds