Doing faccessat("/afs/some/directory", 0) triggers a BUG in the permissions
check code.
Fix this by just removing the BUG section. If no permissions are asked
for, just return okay if the file exists.
Also:
(1) Split up the directory check so that it has separate if-statements
rather than if-else-if (e.g. checking for MAY_EXEC shouldn't skip the
check for MAY_READ and MAY_WRITE).
(2) Check for MAY_CHDIR as MAY_EXEC.
Without the main fix, the following BUG may occur:
kernel BUG at fs/afs/security.c:386!
invalid opcode: 0000 [#1] SMP PTI
...
RIP: 0010:afs_permission+0x19d/0x1a0 [kafs]
...
Call Trace:
? inode_permission+0xbe/0x180
? do_faccessat+0xdc/0x270
? do_syscall_64+0x60/0x1f0
? entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fixes: 00d3b7a453 ("[AFS]: Add security support.")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Some AFS servers refuse to accept unencrypted traffic, so can't be accessed
with kAFS. Set the AF_RXRPC security level to encrypt client calls to deal
with this.
Note that incoming service calls are set by the remote client and so aren't
affected by this.
This requires an AF_RXRPC patch to pass the value set by setsockopt to calls
begun by the kernel.
Signed-off-by: David Howells <dhowells@redhat.com>
The handling of CB.CallBack messages sent by the fileserver to the client
is broken in that they are currently being processed after the reply has
been transmitted.
This is not what the fileserver expects, however. It holds up change
visibility until the reply comes so as to maintain cache coherency, and so
expects the client to have to refetch the state on the affected files.
Fix CB.CallBack handling to perform the callback break before sending the
reply.
The fileserver is free to hold up status fetches issued by other threads on
the same client that occur in reponse to the callback until any pending
changes have been committed.
Fixes: d001648ec7 ("rxrpc: Don't expose skbs to in-kernel users [ver #2]")
Signed-off-by: David Howells <dhowells@redhat.com>
It's possible for an AFS file server to issue a whole-volume notification
that callbacks on all the vnodes in the file have been broken. This is
done for R/O and backup volumes (which don't have per-file callbacks) and
for things like a volume being taken offline.
Fix callback handling to detect whole-volume notifications, to track it
across operations and to check it during inode validation.
Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
If the client cache manager operations that need the server record
(CB.Callback, CB.InitCallBackState, and CB.InitCallBackState3) can't find
the server record, they abort the call from the file server with
RX_CALL_DEAD when they should return okay.
Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the handling of the CB.InitCallBackState3 service call to find the
record of a server that we're using by looking it up by the UUID passed as
the parameter rather than by its address (of which it might have many, and
which may change).
Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
If a volume location record lists multiple file servers for a volume, then
it's possible that due to a misconfiguration or a changing configuration
that one of the file servers doesn't know about it yet and will abort
VNOVOL. Currently, the rotation algorithm will stop with EREMOTEIO.
Fix this by moving on to try the next server if VNOVOL is returned. Once
all the servers have been tried and the record rechecked, the algorithm
will stop with EREMOTEIO or ENOMEDIUM.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The OpenAFS server's RXAFS_InlineBulkStatus implementation has a bug
whereby if an error occurs on one of the vnodes being queried, then the
errorCode field is set correctly in the corresponding status, but the
interfaceVersion field is left unset.
Fix kAFS to deal with this by evaluating the AFSFetchStatus blob against
the following cases when called from FS.InlineBulkStatus delivery:
(1) If InterfaceVersion == 0 then:
(a) If errorCode != 0 then it indicates the abort code for the
corresponding vnode.
(b) If errorCode == 0 then the status record is invalid.
(2) If InterfaceVersion == 1 then:
(a) If errorCode != 0 then it indicates the abort code for the
corresponding vnode.
(b) If errorCode == 0 then the status record is valid and can be
parsed.
(3) If InterfaceVersion is anything else then the status record is
invalid.
Fixes: dd9fbcb8e1 ("afs: Rearrange status mapping")
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The server rotation algorithm just gives up if it fails to probe a
fileserver. Fix this by rotating to the next fileserver instead.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
The refcounting on afs_cb_interest struct objects in
afs_register_server_cb_interest() is wrong as it uses the server list
entry's call back interest pointer without regard for the fact that it
might be replaced at any time and the object thrown away.
Fix this by:
(1) Put a lock on the afs_server_list struct that can be used to
mediate access to the callback interest pointers in the servers array.
(2) Keep a ref on the callback interest that we get from the entry.
(3) Dropping the old reference held by vnode->cb_interest if we replace
the pointer.
Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
When a server record is destroyed, we want to send a message to the server
telling it that we're giving up all the callbacks it has promised us.
Apply two fixes to this:
(1) Only send the FS.GiveUpAllCallBacks message if we actually got a
callback from that server. We assume this to be the case if we
performed at least one successful FS operation on that server.
(2) Send it to the address last used for that server rather than always
picking the first address in the list (which might be unreachable).
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
The parsing of port specifiers in the address list obtained from the DNS
resolution upcall doesn't work as in4_pton() and in6_pton() will fail on
encountering an unexpected delimiter (in this case, the '+' marking the
port number). However, in*_pton() can't be given multiple specifiers.
Fix this by finding the delimiter in advance and not relying on in*_pton()
to find the end of the address for us.
Fixes: 8b2a464ced ("afs: Add an address list concept")
Signed-off-by: David Howells <dhowells@redhat.com>
The afs directory loading code (primarily afs_read_dir()) locks all the
pages that hold a directory's content blob to defend against
getdents/getdents races and getdents/lookup races where the competitors
issue conflicting reads on the same data. As the reads will complete
consecutively, they may retrieve different versions of the data and
one may overwrite the data that the other is busy parsing.
Fix this by not locking the pages at all, but rather by turning the
validation lock into an rwsem and getting an exclusive lock on it whilst
reading the data or validating the attributes and a shared lock whilst
parsing the data. Sharing the attribute validation lock should be fine as
the data fetch will retrieve the attributes also.
The individual page locks aren't needed at all as the only place they're
being used is to serialise data loading.
Without this patch, the:
if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
...
}
part of afs_read_dir() may be skipped, leaving the pages unlocked when we
hit the success: clause - in which case we try to unlock the not-locked
pages, leading to the following oops:
page:ffffe38b405b4300 count:3 mapcount:0 mapping:ffff98156c83a978 index:0x0
flags: 0xfffe000001004(referenced|private)
raw: 000fffe000001004 ffff98156c83a978 0000000000000000 00000003ffffffff
raw: dead000000000100 dead000000000200 0000000000000001 ffff98156b27c000
page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
page->mem_cgroup:ffff98156b27c000
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1205!
...
RIP: 0010:unlock_page+0x43/0x50
...
Call Trace:
afs_dir_iterate+0x789/0x8f0 [kafs]
? _cond_resched+0x15/0x30
? kmem_cache_alloc_trace+0x166/0x1d0
? afs_do_lookup+0x69/0x490 [kafs]
? afs_do_lookup+0x101/0x490 [kafs]
? key_default_cmp+0x20/0x20
? request_key+0x3c/0x80
? afs_lookup+0xf1/0x340 [kafs]
? __lookup_slow+0x97/0x150
? lookup_slow+0x35/0x50
? walk_component+0x1bf/0x490
? path_lookupat.isra.52+0x75/0x200
? filename_lookup.part.66+0xa0/0x170
? afs_end_vnode_operation+0x41/0x60 [kafs]
? __check_object_size+0x9c/0x171
? strncpy_from_user+0x4a/0x170
? vfs_statx+0x73/0xe0
? __do_sys_newlstat+0x39/0x70
? __x64_sys_getdents+0xc9/0x140
? __x64_sys_getdents+0x140/0x140
? do_syscall_64+0x5b/0x160
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: f3ddee8dc4 ("afs: Fix directory handling")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the kernel call initiation to set the minimum security level for kernel
initiated calls (such as from kAFS) from the sockopt value.
Fixes: 19ffa01c9c ("rxrpc: Use structs to hold connection params and protocol info")
Signed-off-by: David Howells <dhowells@redhat.com>
AF_RXRPC tries to turn on IP_RECVERR and IP_MTU_DISCOVER on the UDP socket
it just opened for communications with the outside world, regardless of the
type of socket. Unfortunately, this doesn't work with an AF_INET6 socket.
Fix this by turning on IPV6_RECVERR and IPV6_MTU_DISCOVER instead if the
socket is of the AF_INET6 family.
Without this, kAFS server and address rotation doesn't work correctly
because the algorithm doesn't detect received network errors.
Fixes: 75b54cb57c ("rxrpc: Add IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
The expect_rx_by call timeout is supposed to be set when a call is started
to indicate that we need to receive a packet by that point. This is
currently put back every time we receive a packet, but it isn't started
when we first send a packet. Without this, the call may wait forever if
the server doesn't deign to reply.
Fix this by setting the timeout upon a successful UDP sendmsg call for the
first DATA packet. The timeout is initiated only for initial transmission
and not for subsequent retries as we don't want the retry mechanism to
extend the timeout indefinitely.
Fixes: a158bdd324 ("rxrpc: Fix call timeouts")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
In do_mount() when the MS_* flags are being converted to MNT_* flags,
MS_RDONLY got accidentally convered to SB_RDONLY.
Undo this change.
Fixes: e462ec50cb ("VFS: Differentiate mount flags (MS_*) from internal superblock flags")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
AFS server records get removed from the net->fs_servers tree when
they're deleted, but not from the net->fs_addresses{4,6} lists, which
can lead to an oops in afs_find_server() when a server record has been
removed, for instance during rmmod.
Fix this by deleting the record from the by-address lists before posting
it for RCU destruction.
The reason this hasn't been noticed before is that the fileserver keeps
probing the local cache manager, thereby keeping the service record
alive, so the oops would only happen when a fileserver eventually gets
bored and stops pinging or if the module gets rmmod'd and a call comes
in from the fileserver during the window between the server records
being destroyed and the socket being closed.
The oops looks something like:
BUG: unable to handle kernel NULL pointer dereference at 000000000000001c
...
Workqueue: kafsd afs_process_async_call [kafs]
RIP: 0010:afs_find_server+0x271/0x36f [kafs]
...
Call Trace:
afs_deliver_cb_init_call_back_state3+0x1f2/0x21f [kafs]
afs_deliver_to_call+0x1ee/0x5e8 [kafs]
afs_process_async_call+0x5b/0xd0 [kafs]
process_one_work+0x2c2/0x504
worker_thread+0x1d4/0x2ac
kthread+0x11f/0x127
ret_from_fork+0x24/0x30
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Processes like ld that do lots of small writes that aren't necessarily
contiguous result in a lot of small StoreData operations to the server, the
idea being that if someone else changes the data on the server, we only
write our changes over that and not the space between. Further, we don't
want to write back empty space if we can avoid it to make it easier for the
server to do sparse files.
However, making lots of tiny RPC ops is a lot less efficient for the server
than one big one because each op requires allocation of resources and the
taking of locks, so we want to compromise a bit.
Reduce the load by the following:
(1) If a file is just created locally or has just been truncated with
O_TRUNC locally, allow subsequent writes to the file to be merged with
intervening space if that space doesn't cross an entire intervening
page.
(2) Don't flush the file on ->flush() but rather on ->release() if the
file was open for writing.
Just linking vmlinux.o, without this patch, looking in /proc/fs/afs/stats:
file-wr : n=441 nb=513581204
and after the patch:
file-wr : n=62 nb=513668555
there were 379 fewer StoreData RPC operations at the expense of an extra
87K being written.
Signed-off-by: David Howells <dhowells@redhat.com>
Add statistics to /proc/fs/afs/stats for data transfer RPC operations. New
lines are added that look like:
file-rd : n=55794 nb=10252282150
file-wr : n=9789 nb=3247763645
where n= indicates the number of ops completed and nb= indicates the number
of bytes successfully transferred. file-rd is the counts for read/fetch
operations and file-wr the counts for write/store operations.
Note that directory and symlink downloading are included in the file-rd
stats at the moment.
Signed-off-by: David Howells <dhowells@redhat.com>
Locally edit the contents of an AFS directory upon a successful inode
operation that modifies that directory (such as mkdir, create and unlink)
so that we can avoid the current practice of re-downloading the directory
after each change.
This is viable provided that the directory version number we get back from
the modifying RPC op is exactly incremented by 1 from what we had
previously. The data in the directory contents is in a defined format that
we have to parse locally to perform lookups and readdir, so modifying isn't
a problem.
If the edit fails, we just clear the VALID flag on the directory and it
will be reloaded next time it is needed.
Signed-off-by: David Howells <dhowells@redhat.com>
Adjust the AFS directory XDR structures in a number of superficial ways:
(1) Rename them to all begin afs_xdr_.
(2) Use u8 instead of uint8_t.
(3) Mark the structures as __packed so they don't get rearranged by the
compiler.
(4) Rename the hdr member of afs_xdr_dir_block to meta.
(5) Rename the pagehdr member of afs_xdr_dir_block to hdr.
Signed-off-by: David Howells <dhowells@redhat.com>
Split the directory content definitions into a header file so that they can
be used by multiple .c files.
Signed-off-by: David Howells <dhowells@redhat.com>
AFS directories are structured blobs that are downloaded just like files
and then parsed by the lookup and readdir code and, as such, are currently
handled in the pagecache like any other file, with the entire directory
content being thrown away each time the directory changes.
However, since the blob is a known structure and since the data version
counter on a directory increases by exactly one for each change committed
to that directory, we can actually edit the directory locally rather than
fetching it from the server after each locally-induced change.
What we can't do, though, is mix data from the server and data from the
client since the server is technically at liberty to rearrange or compress
a directory if it sees fit, provided it updates the data version number
when it does so and breaks the callback (ie. sends a notification).
Further, lookup with lookup-ahead, readdir and, when it arrives, local
editing are likely want to scan the whole of a directory.
So directory handling needs to be improved to maintain the coherency of the
directory blob prior to permitting local directory editing.
To this end:
(1) If any directory page gets discarded, invalidate and reread the entire
directory.
(2) If readpage notes that if when it fetches a single page that the
version number has changed, the entire directory is flagged for
invalidation.
(3) Read as much of the directory in one go as we can.
Note that this removes local caching of directories in fscache for the
moment as we can't pass the pages to fscache_read_or_alloc_pages() since
page->lru is in use by the LRU.
Signed-off-by: David Howells <dhowells@redhat.com>
Split the AFS dynamic root stuff out of the main directory handling file
and into its own file as they share little in common.
The dynamic root code also gets its own dentry and inode ops tables.
Signed-off-by: David Howells <dhowells@redhat.com>
Each afs dentry is tagged with the version that the parent directory was at
last time it was validated and, currently, if this differs, the directory
is scanned and the dentry is refreshed.
However, this leads to an excessive amount of revalidation on directories
that get modified on the client without conflict with another client. We
know there's no conflict because the parent directory's data version number
got incremented by exactly 1 on any create, mkdir, unlink, etc., therefore
we can trust the current state of the unaffected dentries when we perform a
local directory modification.
Optimise by keeping track of the last version of the parent directory that
was changed outside of the client in the parent directory's vnode and using
that to validate the dentries rather than the current version.
Signed-off-by: David Howells <dhowells@redhat.com>
Rearrange the AFSFetchStatus to inode attribute mapping code in a number of
ways:
(1) Use an XDR structure rather than a series of incremented pointer
accesses when decoding an AFSFetchStatus object. This allows
out-of-order decode.
(2) Don't store the if_version value but rather just check it and abort if
it's not something we can handle.
(3) Store the owner and group in the status record as raw values rather
than converting them to kuid/kgid. Do that when they're mapped into
i_uid/i_gid.
(4) Validate the type and abort code up front and abort if they're wrong.
(5) Split the inode attribute setting out into its own function from the
XDR decode of an AFSFetchStatus object. This allows it to be called
from elsewhere too.
(6) Differentiate changes to data from changes to metadata.
(7) Use the split-out attribute mapping function from afs_iget().
Signed-off-by: David Howells <dhowells@redhat.com>
Store the data version number indicated by an FS.FetchData op into the read
request structure so that it's accessible by the page reader.
Signed-off-by: David Howells <dhowells@redhat.com>
We no longer parse symlinks when we get the inode to determine if this
symlink is actually a mountpoint as we detect that by examining the mode
instead (symlinks are always 0777 and mountpoints 0644).
Access the cache after mapping the status so that we don't have to manually
set the inode size now.
Note that this may need adjusting if the disconnected operation is
implemented as the file metadata may have to be obtained from the cache.
Signed-off-by: David Howells <dhowells@redhat.com>
Introduce a proc file that displays a bunch of statistics for the AFS
filesystem in the current network namespace.
Signed-off-by: David Howells <dhowells@redhat.com>
Implement @cell substitution handling such that if @cell is seen as a name
in a dynamic root mount, then the name of the root cell for that network
namespace will be substituted for @cell during lookup.
The substitution of @cell for the current net namespace is set by writing
the cell name to /proc/fs/afs/rootcell. The value can be obtained by
reading the file.
For example:
# mount -t afs none /kafs -o dyn
# echo grand.central.org >/proc/fs/afs/rootcell
# ls /kafs/@cell
archive/ cvs/ doc/ local/ project/ service/ software/ user/ www/
# cat /proc/fs/afs/rootcell
grand.central.org
Signed-off-by: David Howells <dhowells@redhat.com>
Implement the AFS feature by which @sys at the end of a pathname component
may be substituted for one of a list of values, typically naming the
operating system. Up to 16 alternatives may be specified and these are
tried in turn until one works. Each network namespace has[*] a separate
independent list.
Upon creation of a new network namespace, the list of values is
initialised[*] to a single OpenAFS-compatible string representing arch type
plus "_linux26". For example, on x86_64, the sysname is "amd64_linux26".
[*] Or will, once network namespace support is finalised in kAFS.
The list may be set by:
# for i in foo bar linux-x86_64; do echo $i; done >/proc/fs/afs/sysname
for which separate writes to the same fd are amalgamated and applied on
close. The LF character may be used as a separator to specify multiple
items in the same write() call.
The list may be cleared by:
# echo >/proc/fs/afs/sysname
and read by:
# cat /proc/fs/afs/sysname
foo
bar
linux-x86_64
Signed-off-by: David Howells <dhowells@redhat.com>
When afs_lookup() is called, prospectively look up the next 50 uncached
fids also from that same directory and cache the results, rather than just
looking up the one file requested.
This allows us to use the FS.InlineBulkStatus RPC op to increase efficiency
by fetching up to 50 file statuses at a time.
Signed-off-by: David Howells <dhowells@redhat.com>
AFS cells that are added or set as the workstation cell through /proc are
pinned against removal by setting the AFS_CELL_FL_NO_GC flag on them and
taking a ref. The ref should be only taken if the flag wasn't already set.
Fix this by making it conditional.
Without this an assertion failure will occur during module removal
indicating that the refcount is too elevated.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix warnings raised by checker, including:
(*) Warnings raised by unequal comparison for the purposes of sorting,
where the endianness doesn't matter:
fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer
(*) afs_set_cb_interest() is not actually used and can be removed.
(*) afs_cell_gc_delay() should be provided with a sysctl.
(*) afs_cell_destroy() needs to use rcu_access_pointer() to read
cell->vl_addrs.
(*) afs_init_fs_cursor() should be static.
(*) struct afs_vnode::permit_cache needs to be marked __rcu.
(*) afs_server_rcu() needs to use rcu_access_pointer().
(*) afs_destroy_server() should use rcu_access_pointer() on
server->addresses as the server object is no longer accessible.
(*) afs_find_server() casts __be16/__be32 values to int in order to
directly compare them for the purpose of finding a match in a list,
but is should also annotate the cast with __force to avoid checker
warnings.
(*) afs_check_permit() accesses vnode->permit_cache outside of the RCU
readlock, though it doesn't then access the value; the extraneous
access is deleted.
False positives:
(*) Conditional locking around the code in xdr_decode_AFSFetchStatus. This
can be dealt with in a separate patch.
fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block
(*) Incorrect handling of seq-retry lock context balance:
fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different
lock contexts for basic block
fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block
fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block
Errors:
(*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go
round again if it successfully found the workstation cell.
(*) Fix UUID decode in afs_deliver_cb_probe_uuid().
(*) afs_cache_permit() has a missing rcu_read_unlock() before one of the
jumps to the someone_else_changed_it label. Move the unlock to after
the label.
(*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when
encoding to XDR.
(*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl()
when decoding from XDR.
Signed-off-by: David Howells <dhowells@redhat.com>
Remove the const marking from the actor function pointer in the dir_context
struct. The const prevents the structure from being used as part of a
kmalloc'd object as it makes the compiler require that the actor member be
set at object initialisation time (or not at all), incuring something like
the following error if you try and set it later:
fs/afs/dir.c:556:20: error: assignment of read-only member 'actor'
Marking the member const like this adds very little in the way of sanity
checking as the type checking system is likely to provide sufficient - and
if not, the kernel is very likely to oops repeatably in this case.
Fixes: ac6614b764 ("[readdir] constify ->actor")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Maintain a catalogue of allocated cookies so that cookie collisions can be
handled properly. For the moment, this just involves printing a warning
and returning a NULL cookie to the caller of fscache_acquire_cookie(), but
in future it might make sense to wait for the old cookie to finish being
cleaned up.
This requires the cookie key to be stored attached to the cookie so that we
still have the key available if the netfs relinquishes the cookie. This is
done by an earlier patch.
The catalogue also renders redundant fscache_netfs_list (used for checking
for duplicates), so that can be removed.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
Pass the object size in to fscache_acquire_cookie() and
fscache_write_page() rather than the netfs providing a callback by which it
can be received. This makes it easier to update the size of the object
when a new page is written that extends the object.
The current object size is also passed by fscache to the check_aux
function, obviating the need to store it in the aux data.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
By analogy with other Rx implementations, RxRPC packet types 9, 10 and 11
should just be discarded rather than being aborted like other undefined
packet types.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Attach copies of the index key and auxiliary data to the fscache cookie so
that:
(1) The callbacks to the netfs for this stuff can be eliminated. This
can simplify things in the cache as the information is still
available, even after the cache has relinquished the cookie.
(2) Simplifies the locking requirements of accessing the information as we
don't have to worry about the netfs object going away on us.
(3) The cache can do lazy updating of the coherency information on disk.
As long as the cache is flushed before reboot/poweroff, there's no
need to update the coherency info on disk every time it changes.
(4) Cookies can be hashed or put in a tree as the index key is easily
available. This allows:
(a) Checks for duplicate cookies can be made at the top fscache layer
rather than down in the bowels of the cache backend.
(b) Caching can be added to a netfs object that has a cookie if the
cache is brought online after the netfs object is allocated.
A certain amount of space is made in the cookie for inline copies of the
data, but if it won't fit there, extra memory will be allocated for it.
The downside of this is that live cache operation requires more memory.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
Add more tracepoints to fscache, including:
(*) fscache_page - Tracks netfs pages known to fscache.
(*) fscache_check_page - Tracks the netfs querying whether a page is
pending storage.
(*) fscache_wake_cookie - Tracks cookies being woken up after a page
completes/aborts storage in the cache.
(*) fscache_op - Tracks operations being initialised.
(*) fscache_wrote_page - Tracks return of the backend write_page op.
(*) fscache_gang_lookup - Tracks lookup of pages to be stored in the write
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
Add some tracepoints to fscache:
(*) fscache_cookie - Tracks a cookie's usage count.
(*) fscache_netfs - Logs registration of a network filesystem, including
the pointer to the cookie allocated.
(*) fscache_acquire - Logs cookie acquisition.
(*) fscache_relinquish - Logs cookie relinquishment.
(*) fscache_enable - Logs enablement of a cookie.
(*) fscache_disable - Logs disablement of a cookie.
(*) fscache_osm - Tracks execution of states in the object state machine.
and cachefiles:
(*) cachefiles_ref - Tracks a cachefiles object's usage count.
(*) cachefiles_lookup - Logs result of lookup_one_len().
(*) cachefiles_mkdir - Logs result of vfs_mkdir().
(*) cachefiles_create - Logs result of vfs_create().
(*) cachefiles_unlink - Logs calls to vfs_unlink().
(*) cachefiles_rename - Logs calls to vfs_rename().
(*) cachefiles_mark_active - Logs an object becoming active.
(*) cachefiles_wait_active - Logs a wait for an old object to be
destroyed.
(*) cachefiles_mark_inactive - Logs an object becoming inactive.
(*) cachefiles_mark_buried - Logs the burial of an object.
Signed-off-by: David Howells <dhowells@redhat.com>
If the fscache asynchronous write operation elects to discard a page that's
pending storage to the cache because the page would be over the store limit
then it needs to wake the page as someone may be waiting on completion of
the write.
The problem is that the store limit may be updated by a different
asynchronous operation - and so may miss the write - and that the store
limit may not even get updated until later by the netfs.
Fix the kernel hang by making fscache_write_op() mark as written any pages
that are over the limit.
Signed-off-by: David Howells <dhowells@redhat.com>
The last parameter to fscache_op_complete() is a bool indicating whether or
not the operation was cancelled. A lot of the time the inverse value is
given or no differentiation is made. Fix this.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix a couple of checker warnings in fscache and cachefiles:
(1) fscache_n_op_requeue is never used, so get rid of it.
(2) cachefiles_uncache_page() is passed in a lock that it releases, so
this needs annotating.
Signed-off-by: David Howells <dhowells@redhat.com>
When relinquishing cookies, either due to iget failure or to inode
eviction, retire a cookie if we think the corresponding vnode got deleted
on the server rather than just letting it lie in the cache.
Signed-off-by: David Howells <dhowells@redhat.com>
AFS vnodes (files) are referenced by a triplet of { volume ID, vnode ID,
uniquifier }. Currently, kafs is only using the vnode ID as the file key
in the volume fscache index and checking the uniquifier on cookie
acquisition against the contents of the auxiliary data stored in the cache.
Unfortunately, this is subject to a race in which an FS.RemoveFile or
FS.RemoveDir op is issued against the server but the local afs inode isn't
torn down and disposed off before another thread issues something like
FS.CreateFile. The latter then gets given the vnode ID that just got
removed, but with a new uniquifier and a cookie collision occurs in the
cache because the cookie is only keyed on the vnode ID whereas the inode is
keyed on the vnode ID plus the uniquifier.
Fix this by keying the cookie on the uniquifier in addition to the vnode ID
and dropping the uniquifier from the auxiliary data supplied.
Signed-off-by: David Howells <dhowells@redhat.com>
Invalidate any data stored in fscache for a vnode that changes on the
server so that we don't end up with the cache in a bad state locally.
Signed-off-by: David Howells <dhowells@redhat.com>
When a new client call is requested, an rxrpc_conn_parameters struct object
is passed in with a bunch of parameters set, such as the local endpoint to
use. A pointer to the target peer record is also placed in there by
rxrpc_get_client_conn() - and this is removed if and only if a new
connection object is allocated. Thus it leaks if a new connection object
isn't allocated.
Fix this by putting any peer object attached to the rxrpc_conn_parameters
object in the function that allocated it.
Fixes: 19ffa01c9c ("rxrpc: Use structs to hold connection params and protocol info")
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc_local objects cannot be disposed of until all the connections that
point to them have been RCU'd as a connection object holds refcount on the
local endpoint it is communicating through. Currently, this can cause an
assertion failure to occur when a network namespace is destroyed as there's
no check that the RCU destructors for the connections have been run before
we start trying to destroy local endpoints.
The kernel reports:
rxrpc: AF_RXRPC: Leaked local 0000000036a41bc1 {5}
------------[ cut here ]------------
kernel BUG at ../net/rxrpc/local_object.c:439!
Fix this by keeping a count of the live connections and waiting for it to
go to zero at the end of rxrpc_destroy_all_connections().
Fixes: dee46364ce ("rxrpc: Add RCU destruction for connections and calls")
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc_call structs don't pin sockets or network namespaces, but may attempt
to access both after their refcount reaches 0 so that they can detach
themselves from the network namespace. However, there's no guarantee that
the socket still exists at this point (so sock_net(&call->socket->sk) may
be invalid) and the namespace may have gone away if the call isn't pinning
a peer.
Fix this by (a) carrying a net pointer in the rxrpc_call struct and (b)
waiting for all calls to be destroyed when the network namespace goes away.
This was detected by checker:
net/rxrpc/call_object.c:634:57: warning: incorrect type in argument 1 (different address spaces)
net/rxrpc/call_object.c:634:57: expected struct sock const *sk
net/rxrpc/call_object.c:634:57: got struct sock [noderef] <asn:4>*<noident>
Fixes: 2baec2c3f8 ("rxrpc: Support network namespacing")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix various issues detected by checker.
Errors:
(*) rxrpc_discard_prealloc() should be using rcu_assign_pointer to set
call->socket.
Warnings:
(*) rxrpc_service_connection_reaper() should be passing NULL rather than 0 to
trace_rxrpc_conn() as the where argument.
(*) rxrpc_disconnect_client_call() should get its net pointer via the
call->conn rather than call->sock to avoid a warning about accessing
an RCU pointer without protection.
(*) Proc seq start/stop functions need annotation as they pass locks
between the functions.
False positives:
(*) Checker doesn't correctly handle of seq-retry lock context balance in
rxrpc_find_service_conn_rcu().
(*) Checker thinks execution may proceed past the BUG() in
rxrpc_publish_service_conn().
(*) Variable length array warnings from SKCIPHER_REQUEST_ON_STACK() in
rxkad.c.
Signed-off-by: David Howells <dhowells@redhat.com>
If a call-level abort is received for the previous call to complete on a
connection channel, then that abort is queued for the connection processor
to handle. Unfortunately, the connection processor then assumes without
checking that the abort is connection-level (ie. callNumber is 0) and
distributes it over all active calls on that connection, thereby
incorrectly aborting them.
Fix this by discarding aborts aimed at a completed call.
Further, discard all packets aimed at a call that's complete if there's
currently an active call on a channel, since the DATA packets associated
with the new call automatically terminate the old call.
Fixes: 18bfeba50d ("rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
rxrpc calls have a ring of packets that are awaiting ACK or retransmission
and a parallel ring of annotations that tracks the state of those packets.
If the initial transmission of a packet on the underlying UDP socket fails
then the packet annotation is marked for resend - but the setting of this
mark accidentally erases the last-packet mark also stored in the same
annotation slot. If this happens, a call won't switch out of the Tx phase
when all the packets have been transmitted.
Fix this by retaining the last-packet mark and only altering the packet
state.
Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
The rxrpc_reduce_call_timer() function should be passed the 'current time'
in jiffies, not the current ktime time. It's confusing in rxrpc_resend
because that has to deal with both. Pass the correct current time in.
Note that this only affects the trace produced and not the functioning of
the code.
Fixes: a158bdd324 ("rxrpc: Fix call timeouts")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the firewall route keepalive part of AF_RXRPC which is currently
function incorrectly by replying to VERSION REPLY packets from the server
with VERSION REQUEST packets.
Instead, send VERSION REPLY packets to the peers of service connections to
act as keep-alives 20s after the latest packet was transmitted to that
peer.
Also, just discard VERSION REPLY packets rather than replying to them.
Signed-off-by: David Howells <dhowells@redhat.com>
Add a tracepoint to track rxrpc calls moving into the completed state and
to log the completion type and the recorded error value and abort code.
Signed-off-by: David Howells <dhowells@redhat.com>
In rxrpc and afs, use the debug_ids that are monotonically allocated to
various objects as they're allocated rather than pointers as kernel
pointers are now hashed making them less useful. Further, the debug ids
aren't reused anywhere nearly as quickly.
In addition, allow kernel services that use rxrpc, such as afs, to take
numbers from the rxrpc counter, assign them to their own call struct and
pass them in to rxrpc for both client and service calls so that the trace
lines for each will have the same ID tag.
Signed-off-by: David Howells <dhowells@redhat.com>
Add a tracepoint to trace packet resend events and to dump the Tx
annotation buffer for added illumination.
Signed-off-by: David Howells <dhowells@rdhat.com>
All the kernel_sendmsg() calls in rxrpc_send_data_packet() need to send
both parts of the iov[] buffer, but one of them does not. Fix it so that
it does.
Without this, short IPv6 rxrpc DATA packets may be seen that have the rxrpc
header included, but no payload.
Fixes: 5a924b8951 ("rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kmalloc() can't always allocate large enough buffers for big_key to use for
crypto (1MB + some metadata) so we cannot use that to allocate the buffer.
Further, vmalloc'd pages can't be passed to sg_init_one() and the aead
crypto accessors cannot be called progressively and must be passed all the
data in one go (which means we can't pass the data in one block at a time).
Fix this by allocating the buffer pages individually and passing them
through a multientry scatterlist to the crypto layer. This has the bonus
advantage that we don't have to allocate a contiguous series of pages.
We then vmap() the page list and pass that through to the VFS read/write
routines.
This can trigger a warning:
WARNING: CPU: 0 PID: 60912 at mm/page_alloc.c:3883 __alloc_pages_nodemask+0xb7c/0x15f8
([<00000000002acbb6>] __alloc_pages_nodemask+0x1ee/0x15f8)
[<00000000002dd356>] kmalloc_order+0x46/0x90
[<00000000002dd3e0>] kmalloc_order_trace+0x40/0x1f8
[<0000000000326a10>] __kmalloc+0x430/0x4c0
[<00000000004343e4>] big_key_preparse+0x7c/0x210
[<000000000042c040>] key_create_or_update+0x128/0x420
[<000000000042e52c>] SyS_add_key+0x124/0x220
[<00000000007bba2c>] system_call+0xc4/0x2b0
from the keyctl/padd/useradd test of the keyutils testsuite on s390x.
Note that it might be better to shovel data through in page-sized lumps
instead as there's no particular need to use a monolithic buffer unless the
kernel itself wants to access the data.
Fixes: 13100a72f4 ("Security: Keys: Big keys stored encrypted")
Reported-by: Paul Bunyan <pbunyan@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Kirill Marinushkin <k.marinushkin@gmail.com>
Due to a check recently added to copy_to_user(), it's now not permitted to
copy from slab-held data to userspace unless the slab is whitelisted. This
affects rxrpc_recvmsg() when it attempts to place an RXRPC_USER_CALL_ID
control message in the userspace control message buffer. A warning is
generated by usercopy_warn() because the source is the copy of the
user_call_ID retained in the rxrpc_call struct.
Work around the issue by copying the user_call_ID to a variable on the
stack and passing that to put_cmsg().
The warning generated looks like:
Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLUB object 'dmaengine-unmap-128' (offset 680, size 8)!
WARNING: CPU: 0 PID: 1401 at mm/usercopy.c:81 usercopy_warn+0x7e/0xa0
...
RIP: 0010:usercopy_warn+0x7e/0xa0
...
Call Trace:
__check_object_size+0x9c/0x1a0
put_cmsg+0x98/0x120
rxrpc_recvmsg+0x6fc/0x1010 [rxrpc]
? finish_wait+0x80/0x80
___sys_recvmsg+0xf8/0x240
? __clear_rsb+0x25/0x3d
? __clear_rsb+0x15/0x3d
? __clear_rsb+0x25/0x3d
? __clear_rsb+0x15/0x3d
? __clear_rsb+0x25/0x3d
? __clear_rsb+0x15/0x3d
? __clear_rsb+0x25/0x3d
? __clear_rsb+0x15/0x3d
? finish_task_switch+0xa6/0x2b0
? trace_hardirqs_on_caller+0xed/0x180
? _raw_spin_unlock_irq+0x29/0x40
? __sys_recvmsg+0x4e/0x90
__sys_recvmsg+0x4e/0x90
do_syscall_64+0x7a/0x220
entry_SYSCALL_64_after_hwframe+0x26/0x9b
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
AF_RXRPC is incorrectly sending back to the server any abort it receives
for a client connection. This is due to the final-ACK offload to the
connection event processor patch. The abort code is copied into the
last-call information on the connection channel and then the event
processor is set.
Instead, the following should be done:
(1) In the case of a final-ACK for a successful call, the ACK should be
scheduled as before.
(2) In the case of a locally generated ABORT, the ABORT details should be
cached for sending in response to further packets related to that
call and no further action scheduled at call disconnect time.
(3) In the case of an ACK received from the peer, the call should be
considered dead, no ABORT should be transmitted at this time. In
response to further non-ABORT packets from the peer relating to this
call, an RX_USER_ABORT ABORT should be transmitted.
(4) In the case of a call killed due to network error, an RX_USER_ABORT
ABORT should be cached for transmission in response to further
packets, but no ABORT should be sent at this time.
Fixes: 3136ef49a1 ("rxrpc: Delay terminal ACK transmission on a client call")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support the AFS dynamic root which is a pseudo-volume that doesn't connect
to any server resource, but rather is just a root directory that
dynamically creates mountpoint directories where the name of such a
directory is the name of the cell.
Such a mount can be created thus:
mount -t afs none /afs -o dyn
Dynamic root superblocks aren't shared except by bind mounts and
propagation. Cell root volumes can then be mounted by referring to them by
name, e.g.:
ls /afs/grand.central.org/
ls /afs/.grand.central.org/
The kernel will upcall to consult the DNS if the address wasn't supplied
directly.
Signed-off-by: David Howells <dhowells@redhat.com>
Rearrange afs_select_fileserver() a little to put the use_server chunk
before the next_server chunk so that with the removal of a couple of gotos
the main path through the function is all one sequence.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix server list handling in the following ways:
(1) In afs_alloc_volume(), remove duplicate server list build code. This
was already done by afs_alloc_server_list() which afs_alloc_volume()
previously called. This just results in twice as many VL RPCs.
(2) In afs_deliver_vl_get_entry_by_name_u(), use the number of server
records indicated by ->nServers in the UVLDB record returned by the
VL.GetEntryByNameU RPC call rather than scanning all NMAXNSERVERS
slots. Unused slots may contain garbage.
(3) In afs_alloc_server_list(), don't stop converting a UVLDB record into
a server list just because we can't look up one of the servers. Just
skip that server and go on to the next. If we can't look up any of
the servers then we'll fail at the end.
Without this patch, an attempt to view the umich.edu root cell using
something like "ls /afs/umich.edu" on a dynamic root (future patch) mount
or an autocell mount will result in ENOMEDIUM. The failure is due to kafs
not stopping after nServers'worth of records have been read, but then
trying to access a server with a garbage UUID and getting an error, which
aborts the server list build.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
In afs_select_fileserver(), we need to clear the ->responded flag in the
address list when reusing it. We should also clear it in
afs_select_current_fileserver().
To this end, just memset() the object before initialising it.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
afs_select_fileserver() ends the address cursor it is using in the case in
which we get some sort of network error and run out of addresses to iterate
through, before it jumps to try the next server. This also needs to be
done when the server aborts with some sort of error that means we should
try the next server.
Fix this by:
(1) Move the iterate_address afs_end_cursor() call to the next_server
case.
(2) End the cursor in the failed case.
(3) Make afs_end_cursor() clear the ->begun flag and ->addr pointer in the
address cursor.
(4) Make afs_end_cursor() able to be called on an already cleared cursor.
Without this, something like the following oops may occur:
AFS: Assertion failed
18446612134397189888 == 0 is false
0xffff88007c279f00 == 0x0 is false
------------[ cut here ]------------
kernel BUG at fs/afs/rotate.c:360!
RIP: 0010:afs_select_fileserver+0x79b/0xa30 [kafs]
Call Trace:
afs_statfs+0xcc/0x180 [kafs]
? p9_client_statfs+0x9e/0x110 [9pnet]
? _cond_resched+0x19/0x40
statfs_by_dentry+0x6d/0x90
vfs_statfs+0x1b/0xc0
user_statfs+0x4b/0x80
SYSC_statfs+0x15/0x30
SyS_statfs+0xe/0x10
entry_SYSCALL_64_fastpath+0x20/0x83
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
afs_alloc_volume() needs to release the cell ref it obtained in the case of
an error. Fix this by adding an afs_put_cell() call into the error path.
This can triggered when a lookup for a cell in a dynamic root or an
autocell mount returns an error whilst trying to look up the server (such
as ENOMEDIUM). This results in an assertion failure oops when the module
is unloaded due to outstanding refs on a cell record.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
There doesn't seem to be any need to have the INIT_SIGNALS and INIT_SIGHAND
macros, so expand them in their single places of use and remove them.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.
The following symbols are then made available from INIT_TASK_DATA() linker
script macro:
init_thread_union
init_stack
INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack. init_thread_union is given its own section so that
it can be placed into the stack space in the right order. I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
afs_write_end() is missing page unlock and put if afs_fill_page() fails.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Repeating creation and deletion of a file on an afs mount will run the box
out of memory, e.g.:
dd if=/dev/zero of=/afs/scratch/m0 bs=$((1024*1024)) count=512
rm /afs/scratch/m0
The problem seems to be that it's not properly decrementing the nlink count
so that the inode can be scrapped.
Note that this doesn't fix local creation followed by remote deletion.
That's harder to handle and will require a separate patch as we're not told
that the file has been deleted - only that the directory has changed.
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the default for fscache_maybe_release_page() for when the cookie isn't
valid or the page isn't cached. It mustn't return false as that indicates
the page cannot yet be freed.
The problem with the default is that if, say, there's no cache, but a
network filesystem's pages are using up almost all the available memory, a
system can OOM because the filesystem ->releasepage() op will not allow
them to be released as fscache_maybe_release_page() incorrectly prevents
it.
This can be tested by writing a sequence of 512MiB files to an AFS mount.
It does not affect NFS or CIFS because both of those wrap the call in a
check of PG_fscache and it shouldn't bother Ceph as that only has
PG_private set whilst writeback is in progress. This might be an issue for
9P, however.
Note that the pages aren't entirely stuck. Removing a file or unmounting
will clear things because that uses ->invalidatepage() instead.
Fixes: 201a15428b ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
cc: stable@vger.kernel.org # 2.6.32+
In rxrpc_release_sock() there may be no rx->local value to access, so we
can't unconditionally follow it to the rxrpc network namespace information
to poke the connection reapers.
Instead, use the socket's namespace pointer to find the namespace.
This unfixed code causes the following static checker warning:
net/rxrpc/af_rxrpc.c:898 rxrpc_release_sock()
error: we previously assumed 'rx->local' could be null (see line 887)
Fixes: 3d18cbb7fd ("rxrpc: Fix conn expiry timers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an AFS inode is allocated by afs_alloc_inode(), the allocated
afs_vnode struct isn't necessarily reset from the last time it was used as
an inode because the slab constructor is only invoked once when the memory
is obtained from the page allocator.
This means that information can leak from one inode to the next because
we're not calling kmem_cache_zalloc(). Some of the information isn't
reset, in particular the permit cache pointer.
Bring the clearances up to date.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Fix four refcount bugs in afs_cache_permit():
(1) When checking the result of the kzalloc(), we can't just return, but
must put 'permits'.
(2) We shouldn't put permits immediately after hashing a new permit as we
need to keep the pointer stable so that we can check to see if
vnode->permit_cache has changed before we decide whether to assign to
it.
(3) 'permits' is being put twice.
(4) We need to put either the replacement or the thing replaced after the
assignment to vnode->permit_cache.
Without this, lots of the following are seen:
Kernel BUG at ffffffffa039857b [verbose debug info unavailable]
------------[ cut here ]------------
Kernel BUG at ffffffffa039858a [verbose debug info unavailable]
------------[ cut here ]------------
The addresses are in the .text..refcount section of the kafs.ko module.
Following the relocation records for the __ex_table section shows one to be
due to the decrement in afs_put_permits() and the other to be key_get() in
afs_cache_permit().
Occasionally, the following is seen:
refcount_t overflow at afs_cache_permit+0x57d/0x5c0 [kafs] in cc1[562], uid/euid: 0/0
WARNING: CPU: 0 PID: 562 at kernel/panic.c:657 refcount_error_report+0x9c/0xac
...
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Repeat terminal ACKs and now terminal ACKs are now generated from the
connection event processor rather from call handling as this allows us to
discard client call structures as soon as possible and free up the channel
for a follow on call.
However, in ACKs so generated, the additional information trailer is
malformed because the padding that's meant to be in the middle isn't
included in what's transmitted.
Fix it so that the 3 bytes of padding are included in the transmission.
Further, the trailer is misaligned because of the padding, so assigment to
the u16 and u32 fields inside it might cause problems on some arches, so
fix this by breaking the padding and the trailer out of the packed struct.
(This also deals with potential compiler weirdies where some of the nested
structs are packed and some aren't).
The symptoms can be seen in wireshark as terminal DUPLICATE or IDLE ACK
packets in which the Max MTU, Interface MTU and rwind fields have weird
values and the Max Packets field is apparently missing.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
afs_mkdir(), afs_create(), afs_link() and afs_symlink() all need to drop
the target dentry if a signal causes the operation to be killed immediately
before we try to contact the server.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix some of dentry handling in AFS directory ops:
(1) Do d_drop() on the new_dentry before assigning a new inode to it in
afs_vnode_new_inode(). It's fine to do this before calling afs_iget()
because the operation has taken place on the server.
(2) Replace d_instantiate()/d_rehash() with d_add().
(3) Don't d_drop() the new_dentry in afs_rename() on error.
Also fix afs_link() and afs_rename() to call key_put() on all error paths
where the key is taken.
Signed-off-by: David Howells <dhowells@redhat.com>
Make afs_write_begin() wait for a page that's marked PG_writeback because:
(1) We need to avoid interference with the data being stored so that the
data on the server ends up in a defined state.
(2) page->private is used to track the window of dirty data within a page,
but it's also used by the storage code to track what's being written,
being cleared by the completion notification. Ownership can't be
relinquished by the storage code until completion because it a store
fails, the data must be remarked dirty.
Tracing shows something like the following (edited):
x86_64-linux-gn-15940 [1] afs_page_dirty: vn=ffff8800bef33800 9c75 begin 0-125
kworker/u8:3-114 [2] afs_page_dirty: vn=ffff8800bef33800 9c75 store+ 0-125
x86_64-linux-gn-15940 [1] afs_page_dirty: vn=ffff8800bef33800 9c75 begin 0-2052
kworker/u8:3-114 [2] afs_page_dirty: vn=ffff8800bef33800 9c75 clear 0-2052
kworker/u8:3-114 [2] afs_page_dirty: vn=ffff8800bef33800 9c75 store 0-0
kworker/u8:3-114 [2] afs_page_dirty: vn=ffff8800bef33800 9c75 WARN 0-0
The clear (completion) corresponding to the store+ (store continuation from
a previous page) happens between the second begin (afs_write_begin) and the
store corresponding to that. This results in the second store not seeing
any data to write back, leading to the following warning:
WARNING: CPU: 2 PID: 114 at ../fs/afs/write.c:403 afs_write_back_from_locked_page+0x19d/0x76c [kafs]
Modules linked in: kafs(E)
CPU: 2 PID: 114 Comm: kworker/u8:3 Tainted: G E 4.14.0-fscache+ #242
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: writeback wb_workfn (flush-afs-2)
task: ffff8800cad72600 task.stack: ffff8800cad44000
RIP: 0010:afs_write_back_from_locked_page+0x19d/0x76c [kafs]
RSP: 0018:ffff8800cad47aa0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: ffff8800bef33a20 RCX: 0000000000000000
RDX: 000000000000000f RSI: ffffffff81c5d0e0 RDI: ffff8800cad72e78
RBP: ffff8800d31ea1e8 R08: ffff8800c1358000 R09: ffff8800ca00e400
R10: ffff8800cad47a38 R11: ffff8800c5d9e400 R12: 0000000000000000
R13: ffffea0002d9df00 R14: ffffffffa0023c1c R15: 0000000000007fdf
FS: 0000000000000000(0000) GS:ffff8800ca700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f85ac6c4000 CR3: 0000000001c10001 CR4: 00000000001606e0
Call Trace:
? clear_page_dirty_for_io+0x23a/0x267
afs_writepages_region+0x1be/0x286 [kafs]
afs_writepages+0x60/0x127 [kafs]
do_writepages+0x36/0x70
__writeback_single_inode+0x12f/0x635
writeback_sb_inodes+0x2cc/0x452
__writeback_inodes_wb+0x68/0x9f
wb_writeback+0x208/0x470
? wb_workfn+0x22b/0x565
wb_workfn+0x22b/0x565
? worker_thread+0x230/0x2ac
process_one_work+0x2cc/0x517
? worker_thread+0x230/0x2ac
worker_thread+0x1d4/0x2ac
? rescuer_thread+0x29b/0x29b
kthread+0x15d/0x165
? kthread_create_on_node+0x3f/0x3f
? call_usermodehelper_exec_async+0x118/0x11f
ret_from_fork+0x24/0x30
Signed-off-by: David Howells <dhowells@redhat.com>
David Howells