[ 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: 34fa47612b ("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>
[ Upstream commit 7903192c4b ]
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: 781070551c ("afs: Fix calculation of callback expiry time")
Fixes: 2070a3e449 ("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>
[ Upstream commit de696c4784 ]
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>
-----BEGIN PGP SIGNATURE-----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=YVwD
-----END PGP SIGNATURE-----
Merge tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"There's some core VFS changes which affect a couple of filesystems:
- Make the inode hash table RCU safe and providing some RCU-safe
accessor functions. The search can then be done without taking the
inode_hash_lock. Care must be taken because the object may be being
deleted and no wait is made.
- Allow iunique() to avoid taking the inode_hash_lock.
- Allow AFS's callback processing to avoid taking the inode_hash_lock
when using the inode table to find an inode to notify.
- Improve Ext4's time updating. Konstantin Khlebnikov said "For now,
I've plugged this issue with try-lock in ext4 lazy time update.
This solution is much better."
Then there's a set of changes to make a number of improvements to the
AFS driver:
- Improve callback (ie. third party change notification) processing
by:
(a) Relying more on the fact we're doing this under RCU and by
using fewer locks. This makes use of the RCU-based inode
searching outlined above.
(b) Moving to keeping volumes in a tree indexed by volume ID
rather than a flat list.
(c) Making the server and volume records logically part of the
cell. This means that a server record now points directly at
the cell and the tree of volumes is there. This removes an N:M
mapping table, simplifying things.
- Improve keeping NAT or firewall channels open for the server
callbacks to reach the client by actively polling the fileserver on
a timed basis, instead of only doing it when we have an operation
to process.
- Improving detection of delayed or lost callbacks by including the
parent directory in the list of file IDs to be queried when doing a
bulk status fetch from lookup. We can then check to see if our copy
of the directory has changed under us without us getting notified.
- Determine aliasing of cells (such as a cell that is pointed to be a
DNS alias). This allows us to avoid having ambiguity due to
apparently different cells using the same volume and file servers.
- Improve the fileserver rotation to do more probing when it detects
that all of the addresses to a server are listed as non-responsive.
It's possible that an address that previously stopped responding
has become responsive again.
Beyond that, lay some foundations for making some calls asynchronous:
- Turn the fileserver cursor struct into a general operation struct
and hang the parameters off of that rather than keeping them in
local variables and hang results off of that rather than the call
struct.
- Implement some general operation handling code and simplify the
callers of operations that affect a volume or a volume component
(such as a file). Most of the operation is now done by core code.
- Operations are supplied with a table of operations to issue
different variants of RPCs and to manage the completion, where all
the required data is held in the operation object, thereby allowing
these to be called from a workqueue.
- Put the standard "if (begin), while(select), call op, end" sequence
into a canned function that just emulates the current behaviour for
now.
There are also some fixes interspersed:
- Don't let the EACCES from ICMP6 mapping reach the user as such,
since it's confusing as to whether it's a filesystem error. Convert
it to EHOSTUNREACH.
- Don't use the epoch value acquired through probing a server. If we
have two servers with the same UUID but in different cells, it's
hard to draw conclusions from them having different epoch values.
- Don't interpret the argument to the CB.ProbeUuid RPC as a
fileserver UUID and look up a fileserver from it.
- Deal with servers in different cells having the same UUIDs. In the
event that a CB.InitCallBackState3 RPC is received, we have to
break the callback promises for every server record matching that
UUID.
- Don't let afs_statfs return values that go below 0.
- Don't use running fileserver probe state to make server selection
and address selection decisions on. Only make decisions on final
state as the running state is cleared at the start of probing"
Acked-by: Al Viro <viro@zeniv.linux.org.uk> (fs/inode.c part)
* tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (27 commits)
afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly
afs: Show more a bit more server state in /proc/net/afs/servers
afs: Don't use probe running state to make decisions outside probe code
afs: Fix afs_statfs() to not let the values go below zero
afs: Fix the by-UUID server tree to allow servers with the same UUID
afs: Reorganise volume and server trees to be rooted on the cell
afs: Add a tracepoint to track the lifetime of the afs_volume struct
afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op
afs: Detect cell aliases 2 - Cells with no root volumes
afs: Detect cell aliases 1 - Cells with root volumes
afs: Implement client support for the YFSVL.GetCellName RPC op
afs: Retain more of the VLDB record for alias detection
afs: Fix handling of CB.ProbeUuid cache manager op
afs: Don't get epoch from a server because it may be ambiguous
afs: Build an abstraction around an "operation" concept
afs: Rename struct afs_fs_cursor to afs_operation
afs: Remove the error argument from afs_protocol_error()
afs: Set error flag rather than return error from file status decode
afs: Make callback processing more efficient.
afs: Show more information in /proc/net/afs/servers
...
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>
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>
Set a flag in the call struct to indicate an unmarshalling error rather
than return and handle an error from the decoding of file statuses. This
flag is checked on a successful return from the delivery function.
Signed-off-by: David Howells <dhowells@redhat.com>
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>
Add a helper to directly set the RXRPC_MIN_SECURITY_LEVEL sockopt from
kernel space without going through a fake uaccess.
Thanks to David Howells for the documentation updates.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the handling of signals in client rxrpc calls made by the afs
filesystem. Ignore signals completely, leaving call abandonment or
connection loss to be detected by timeouts inside AF_RXRPC.
Allowing a filesystem call to be interrupted after the entire request has
been transmitted and an abort sent means that the server may or may not
have done the action - and we don't know. It may even be worse than that
for older servers.
Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Signed-off-by: David Howells <dhowells@redhat.com>
When an AFS service handler function aborts a call, AF_RXRPC marks the call
as complete - which means that it's not going to get any more packets from
the receiver. This is a problem because reception of the final ACK is what
triggers afs_deliver_to_call() to drop the final ref on the afs_call
object.
Instead, aborted AFS service calls may then just sit around waiting for
ever or until they're displaced by a new call on the same connection
channel or a connection-level abort.
Fix this by calling afs_set_call_complete() to finalise the afs_call struct
representing the call.
However, we then need to drop the ref that stops the call from being
deallocated. We can do this in afs_set_call_complete(), as the work queue
is holding a separate ref of its own, but then we shouldn't do it in
afs_process_async_call() and afs_delete_async_call().
call->drop_ref is set to indicate that a ref needs dropping for a call and
this is dealt with when we transition a call to AFS_CALL_COMPLETE.
But then we also need to get rid of the ref that pins an asynchronous
client call. We can do this by the same mechanism, setting call->drop_ref
for an async client call too.
We can also get rid of call->incoming since nothing ever sets it and only
one thing ever checks it (futilely).
A trace of the rxrpc_call and afs_call struct ref counting looks like:
<idle>-0 [001] ..s5 164.764892: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_new_incoming_call+0x473/0xb34 a=00000000442095b5
<idle>-0 [001] .Ns5 164.766001: rxrpc_call: c=00000002 QUE u=4 sp=rxrpc_propose_ACK+0xbe/0x551 a=00000000442095b5
<idle>-0 [001] .Ns4 164.766005: rxrpc_call: c=00000002 PUT u=3 sp=rxrpc_new_incoming_call+0xa3f/0xb34 a=00000000442095b5
<idle>-0 [001] .Ns7 164.766433: afs_call: c=00000002 WAKE u=2 o=11 sp=rxrpc_notify_socket+0x196/0x33c
kworker/1:2-1810 [001] ...1 164.768409: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_process_call+0x25/0x7ae a=00000000442095b5
kworker/1:2-1810 [001] ...1 164.769439: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000001 00000000 02 22 ACK CallAck
kworker/1:2-1810 [001] ...1 164.769459: rxrpc_call: c=00000002 PUT u=2 sp=rxrpc_process_call+0x74f/0x7ae a=00000000442095b5
kworker/1:2-1810 [001] ...1 164.770794: afs_call: c=00000002 QUEUE u=3 o=12 sp=afs_deliver_to_call+0x449/0x72c
kworker/1:2-1810 [001] ...1 164.770829: afs_call: c=00000002 PUT u=2 o=12 sp=afs_process_async_call+0xdb/0x11e
kworker/1:2-1810 [001] ...2 164.771084: rxrpc_abort: c=00000002 95786a88:00000008 s=0 a=1 e=1 K-1
kworker/1:2-1810 [001] ...1 164.771461: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000002 00000000 04 00 ABORT CallAbort
kworker/1:2-1810 [001] ...1 164.771466: afs_call: c=00000002 PUT u=1 o=12 sp=SRXAFSCB_ProbeUuid+0xc1/0x106
The abort generated in SRXAFSCB_ProbeUuid(), labelled "K-1", indicates that
the local filesystem/cache manager didn't recognise the UUID as its own.
Fixes: 2067b2b3f4 ("afs: Fix the CB.ProbeUuid service handler to reply correctly")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix a couple of tracelines to indicate the usage count after the atomic op,
not the usage count before it to be consistent with other afs and rxrpc
trace lines.
Change the wording of the afs_call_trace_work trace ID label from "WORK" to
"QUEUE" to reflect the fact that it's queueing work, not doing work.
Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the interruptibility of kernel-initiated client calls so that they're
either only interruptible when they're waiting for a call slot to come
available or they're not interruptible at all. Either way, they're not
interruptible during transmission.
This should help prevent StoreData calls from being interrupted when
writeback is in progress. It doesn't, however, handle interruption during
the receive phase.
Userspace-initiated calls are still interruptable. After the signal has
been handled, sendmsg() will return the amount of data copied out of the
buffer and userspace can perform another sendmsg() call to continue
transmission.
Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Signed-off-by: David Howells <dhowells@redhat.com>
-----BEGIN PGP SIGNATURE-----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=YjAm
-----END PGP SIGNATURE-----
Merge tag 'afs-next-20191121' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"Minor cleanups and fix:
- Minor fix to make some debugging statements display information
from the correct iov_iter.
- Rename some members and variables to make things more obvious or
consistent.
- Provide a helper to wrap increments of the usage count on the
afs_read struct.
- Use scnprintf() to print into a stack buffer rather than sprintf().
- Remove some set but unused variables"
* tag 'afs-next-20191121' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Remove set but not used variable 'ret'
afs: Remove set but not used variables 'before', 'after'
afs: xattr: use scnprintf
afs: Introduce an afs_get_read() refcount helper
afs: Rename desc -> req in afs_fetch_data()
afs: Switch the naming of call->iter and call->_iter
afs: Use call->_iter not &call->iter in debugging statements
Change the name of call->iter to call->def_iter to represent the default
iterator.
Change the name of call->_iter to call->iter to represent the iterator
actually being used.
Signed-off-by: David Howells <dhowells@redhat.com>
In afs_wait_for_call_to_complete(), rather than immediately aborting an
operation if a signal occurs, the code attempts to wait for it to
complete, using a schedule timeout of 2*RTT (or min 2 jiffies) and a
check that we're still receiving relevant packets from the server before
we consider aborting the call. We may even ping the server to check on
the status of the call.
However, there's a missing timeout reset in the event that we do
actually get a packet to process, such that if we then get a couple of
short stalls, we then time out when progress is actually being made.
Fix this by resetting the timeout any time we get something to process.
If it's the failure of the call then the call state will get changed and
we'll exit the loop shortly thereafter.
A symptom of this is data fetches and stores failing with EINTR when
they really shouldn't.
Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----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=wgib
-----END PGP SIGNATURE-----
Merge tag 'afs-next-20190628' of 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
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>
Always ask for the reply time from AF_RXRPC as it's used to calculate the
callback expiry time and lock expiry times, so it's needed by most FS
operations.
Signed-off-by: David Howells <dhowells@redhat.com>
Replace the afs_call::reply[] array with a bunch of typed members so that
the compiler can use type-checking on them. It's also easier for the eye
to see what's going on.
Signed-off-by: David Howells <dhowells@redhat.com>
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: d2ddc776a4 ("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>
Allow kernel services using AF_RXRPC to indicate that a call should be
non-interruptible. This allows kafs to make things like lock-extension and
writeback data storage calls non-interruptible.
If this is set, signals will be ignored for operations on that call where
possible - such as waiting to get a call channel on an rxrpc connection.
It doesn't prevent UDP sendmsg from being interrupted, but that will be
handled by packet retransmission.
rxrpc_kernel_recv_data() isn't affected by this since that never waits,
preferring instead to return -EAGAIN and leave the waiting to the caller.
Userspace initiated calls can't be set to be uninterruptible at this time.
Signed-off-by: David Howells <dhowells@redhat.com>
If an older AFS server doesn't support an operation, it may accept the call
and then sit on it forever, happily responding to pings that make kafs
think that the call is still alive.
Fix this by setting the maximum lifespan of Volume Location service calls
in particular and probe calls in general so that they don't run on
endlessly if they're not supported.
Signed-off-by: David Howells <dhowells@redhat.com>
-----BEGIN PGP SIGNATURE-----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=yiyv
-----END PGP SIGNATURE-----
Merge tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"A set of fix and development patches for AFS for 5.2.
Summary:
- Fix the AFS file locking so that sqlite can run on an AFS mount and
also so that firefox and gnome can use a homedir that's mounted
through AFS.
This required emulation of fine-grained locking when the server
will only support whole-file locks and no upgrade/downgrade. Four
modes are provided, settable by mount parameter:
"flock=local" - No reference to the server
"flock=openafs" - Fine-grained locks are local-only, whole-file
locks require sufficient server locks
"flock=strict" - All locks require sufficient server locks
"flock=write" - Always get an exclusive server lock
If the volume is a read-only or backup volume, then flock=local for
that volume.
- Log extra information for a couple of cases where the client mucks
up somehow: AFS vnode with undefined type and dir check failure -
in both cases we seem to end up with unfilled data, but the issues
happen infrequently and are difficult to reproduce at will.
- Implement silly rename for unlink() and rename().
- Set i_blocks so that du can get some information about usage.
- Fix xattr handlers to return the right amount of data and to not
overflow buffers.
- Implement getting/setting raw AFS and YFS ACLs as xattrs"
* tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Implement YFS ACL setting
afs: Get YFS ACLs and information through xattrs
afs: implement acl setting
afs: Get an AFS3 ACL as an xattr
afs: Fix getting the afs.fid xattr
afs: Fix the afs.cell and afs.volume xattr handlers
afs: Calculate i_blocks based on file size
afs: Log more information for "kAFS: AFS vnode with undefined type\n"
afs: Provide mount-time configurable byte-range file locking emulation
afs: Add more tracepoints
afs: Implement sillyrename for unlink and rename
afs: Add directory reload tracepoint
afs: Handle lock rpc ops failing on a file that got deleted
afs: Improve dir check failure reports
afs: Add file locking tracepoints
afs: Further fix file locking
afs: Fix AFS file locking to allow fine grained locks
afs: Calculate lock extend timer from set/extend reply reception
afs: Split wait from afs_make_call()
Hi Linus,
This is my very first pull-request. I've been working full-time as
a kernel developer for more than two years now. During this time I've
been fixing bugs reported by Coverity all over the tree and, as part
of my work, I'm also contributing to the KSPP. My work in the kernel
community has been supervised by Greg KH and Kees Cook.
OK. So, after the quick introduction above, please, pull the following
patches that mark switch cases where we are expecting to fall through.
These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
They have been ignored for a long time (most of them more than 3 months,
even after pinging multiple times), which is the reason why I've created
this tree. Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
going out for newly introduced code that triggers -Wimplicit-fallthrough
to avoid gaining more of these cases while we work to remove the ones
that are already present.
I'm happy to let you know that we are getting close to completing this
work. Currently, there are only 32 of 2311 of these cases left to be
addressed in linux-next. I'm auditing every case; I take a look into
the code and analyze it in order to determine if I'm dealing with an
actual bug or a false positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the following missing
break/return bugs, some of them introduced more than 5 years ago:
84242b82d87850b51b6c5e420fe63509186e5034b5be8531817264235ee7cc5034a5d2479826cc865340f23df8df997abeeb2f10d82373307b00c5e65d25ff7a54a7ed5b3e7dc24bfa8f21ad0eaee6199ba8376ce1dc586a60a1a8e9b186f14e57562b4860747828eac5b974bee9cc44ba91162c930e3d0a
Once this work is finish, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
-----BEGIN PGP SIGNATURE-----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=k30z
-----END PGP SIGNATURE-----
Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
"Mark switch cases where we are expecting to fall through.
This is part of the ongoing efforts to enable -Wimplicit-fallthrough.
Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next
nag-emails going out for newly introduced code that triggers
-Wimplicit-fallthrough to avoid gaining more of these cases while we
work to remove the ones that are already present.
We are getting close to completing this work. Currently, there are
only 32 of 2311 of these cases left to be addressed in linux-next. I'm
auditing every case; I take a look into the code and analyze it in
order to determine if I'm dealing with an actual bug or a false
positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the several missing
break/return bugs, some of them introduced more than 5 years ago.
Once this work is finished, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again"
* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
memstick: mark expected switch fall-throughs
drm/nouveau/nvkm: mark expected switch fall-throughs
NFC: st21nfca: Fix fall-through warnings
NFC: pn533: mark expected switch fall-throughs
block: Mark expected switch fall-throughs
ASN.1: mark expected switch fall-through
lib/cmdline.c: mark expected switch fall-throughs
lib: zstd: Mark expected switch fall-throughs
scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
scsi: ppa: mark expected switch fall-through
scsi: osst: mark expected switch fall-throughs
scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
scsi: imm: mark expected switch fall-throughs
scsi: csiostor: csio_wr: mark expected switch fall-through
...
Split the call to afs_wait_for_call_to_complete() from afs_make_call() to
make it easier to handle asynchronous calls and to make it easier to
convert a synchronous call to an asynchronous one in future, for instance
when someone tries to interrupt an operation by pressing Ctrl-C.
Signed-off-by: David Howells <dhowells@redhat.com>
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 <dhowells@redhat.com>
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 <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.
In other cases I had to tweak a bit the format of the comments.
This patch suppresses ALL missing-break-in-switch false positives
in fs/afs
Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.
afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.
Fix this by:
(1) Getting an extra ref for an asynchronous call for the call itself to
hold. This makes sure the call doesn't evaporate on us accidentally
and will allow the call to be retained by the caller in a future
patch. The ref is released on leaving afs_make_call() or
afs_wait_for_call_to_complete().
(2) In the event of an error from rxrpc_kernel_send_data():
(a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
call has been aborted and ended. This prevents
afs_deliver_to_call() from doing anything with any notifications
it gets.
(b) Explicitly end the call immediately to prevent further callbacks.
(c) Cancel any queued async_work and wait for the work if it's
executing. This allows us to be sure the race won't recur when we
change the state. We put the work queue's ref on the call if we
managed to cancel it.
(d) Put the call's ref that we got in (1). This belongs to us as long
as the call is in state AFS_CALL_CL_REQUESTING.
Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
The life-checking function, which is used by kAFS to make sure that a call
is still live in the event of a pending signal, only samples the received
packet serial number counter; it doesn't actually provoke a change in the
counter, rather relying on the server to happen to give us a packet in the
time window.
Fix this by adding a function to force a ping to be transmitted.
kAFS then keeps track of whether there's been a stall, and if so, uses the
new function to ping the server, resetting the timeout to allow the reply
to come back.
If there's a stall, a ping and the call is *still* stalled in the same
place after another period, then the call will be aborted.
Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Fixes: f4d15fb6f9 ("rxrpc: Provide functions for allowing cleaner handling of signals")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
Calculate the callback expiration time at the point of operation reply
delivery, using the reply time queried from AF_RXRPC on that call as a
base.
Signed-off-by: David Howells <dhowells@redhat.com>
Implement the YFS cache manager service which gives extra capabilities on
top of AFS. This is done by listening for an additional service on the
same port and indicating that anyone requesting an upgrade should be
upgraded to the YFS port.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix afs_deliver_to_call() to handle -EIO being returned by the operation
delivery function, indicating that the call found itself in the wrong
state, by printing an error and aborting the call.
Currently, an assertion failure will occur. This can happen, say, if the
delivery function falls off the end without calling afs_extract_data() with
the want_more parameter set to false to collect the end of the Rx phase of
a call.
The assertion failure looks like:
AFS: Assertion failed
4 == 7 is false
0x4 == 0x7 is false
------------[ cut here ]------------
kernel BUG at fs/afs/rxrpc.c:462!
and is matched in the trace buffer by a line like:
kworker/7:3-3226 [007] ...1 85158.030203: afs_io_error: c=0003be0c r=-5 CM_REPLY
Fixes: 98bf40cd99 ("afs: Protect call->state changes against signals")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.
Instead:
(1) Put an iterator in the afs_call struct.
(2) Set the iterator for each marshalling stage to load data into the
appropriate places. A number of convenience functions are provided to
this end (eg. afs_extract_to_buf()).
This iterator is then passed to afs_extract_data().
(3) Use the new ITER_DISCARD iterator to discard any excess data provided
by FetchData.
Signed-off-by: David Howells <dhowells@redhat.com>
Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.
Signed-off-by: David Howells <dhowells@redhat.com>
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
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 f014ffb025 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 f014ffb025.
(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: f014ffb025 ("afs: Fix afs_server struct leak")
Fixes: 08e0e7c82e ("[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>
David Howells
Gustavo A. R. Silva
Linus Torvalds
Christoph Hellwig
Thomas Gleixner
Marc Dionne
Gustavo A. R. Silva