Commit Graph

475 Commits

Author SHA1 Message Date
Kees Cook
6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Linus Torvalds
1c8c5a9d38 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add Maglev hashing scheduler to IPVS, from Inju Song.

 2) Lots of new TC subsystem tests from Roman Mashak.

 3) Add TCP zero copy receive and fix delayed acks and autotuning with
    SO_RCVLOWAT, from Eric Dumazet.

 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard
    Brouer.

 5) Add ttl inherit support to vxlan, from Hangbin Liu.

 6) Properly separate ipv6 routes into their logically independant
    components. fib6_info for the routing table, and fib6_nh for sets of
    nexthops, which thus can be shared. From David Ahern.

 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP
    messages from XDP programs. From Nikita V. Shirokov.

 8) Lots of long overdue cleanups to the r8169 driver, from Heiner
    Kallweit.

 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau.

10) Add traffic condition monitoring to iwlwifi, from Luca Coelho.

11) Plumb extack down into fib_rules, from Roopa Prabhu.

12) Add Flower classifier offload support to igb, from Vinicius Costa
    Gomes.

13) Add UDP GSO support, from Willem de Bruijn.

14) Add documentation for eBPF helpers, from Quentin Monnet.

15) Add TLS tx offload to mlx5, from Ilya Lesokhin.

16) Allow applications to be given the number of bytes available to read
    on a socket via a control message returned from recvmsg(), from
    Soheil Hassas Yeganeh.

17) Add x86_32 eBPF JIT compiler, from Wang YanQing.

18) Add AF_XDP sockets, with zerocopy support infrastructure as well.
    From Björn Töpel.

19) Remove indirect load support from all of the BPF JITs and handle
    these operations in the verifier by translating them into native BPF
    instead. From Daniel Borkmann.

20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha.

21) Allow XDP programs to do lookups in the main kernel routing tables
    for forwarding. From David Ahern.

22) Allow drivers to store hardware state into an ELF section of kernel
    dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy.

23) Various RACK and loss detection improvements in TCP, from Yuchung
    Cheng.

24) Add TCP SACK compression, from Eric Dumazet.

25) Add User Mode Helper support and basic bpfilter infrastructure, from
    Alexei Starovoitov.

26) Support ports and protocol values in RTM_GETROUTE, from Roopa
    Prabhu.

27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard
    Brouer.

28) Add lots of forwarding selftests, from Petr Machata.

29) Add generic network device failover driver, from Sridhar Samudrala.

* ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits)
  strparser: Add __strp_unpause and use it in ktls.
  rxrpc: Fix terminal retransmission connection ID to include the channel
  net: hns3: Optimize PF CMDQ interrupt switching process
  net: hns3: Fix for VF mailbox receiving unknown message
  net: hns3: Fix for VF mailbox cannot receiving PF response
  bnx2x: use the right constant
  Revert "net: sched: cls: Fix offloading when ingress dev is vxlan"
  net: dsa: b53: Fix for brcm tag issue in Cygnus SoC
  enic: fix UDP rss bits
  netdev-FAQ: clarify DaveM's position for stable backports
  rtnetlink: validate attributes in do_setlink()
  mlxsw: Add extack messages for port_{un, }split failures
  netdevsim: Add extack error message for devlink reload
  devlink: Add extack to reload and port_{un, }split operations
  net: metrics: add proper netlink validation
  ipmr: fix error path when ipmr_new_table fails
  ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds
  net: hns3: remove unused hclgevf_cfg_func_mta_filter
  netfilter: provide udp*_lib_lookup for nf_tproxy
  qed*: Utilize FW 8.37.2.0
  ...
2018-06-06 18:39:49 -07:00
Linus Torvalds
2857676045 - Introduce arithmetic overflow test helper functions (Rasmus)
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
 - Introduce overflow test module (Rasmus, Kees)
 - Introduce saturating size helper functions (Matthew, Kees)
 - Treewide use of struct_size() for allocators (Kees)
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 Comment: Kees Cook <kees@outflux.net>
 
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Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull overflow updates from Kees Cook:
 "This adds the new overflow checking helpers and adds them to the
  2-factor argument allocators. And this adds the saturating size
  helpers and does a treewide replacement for the struct_size() usage.
  Additionally this adds the overflow testing modules to make sure
  everything works.

  I'm still working on the treewide replacements for allocators with
  "simple" multiplied arguments:

     *alloc(a * b, ...) -> *alloc_array(a, b, ...)

  and

     *zalloc(a * b, ...) -> *calloc(a, b, ...)

  as well as the more complex cases, but that's separable from this
  portion of the series. I expect to have the rest sent before -rc1
  closes; there are a lot of messy cases to clean up.

  Summary:

   - Introduce arithmetic overflow test helper functions (Rasmus)

   - Use overflow helpers in 2-factor allocators (Kees, Rasmus)

   - Introduce overflow test module (Rasmus, Kees)

   - Introduce saturating size helper functions (Matthew, Kees)

   - Treewide use of struct_size() for allocators (Kees)"

* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  treewide: Use struct_size() for devm_kmalloc() and friends
  treewide: Use struct_size() for vmalloc()-family
  treewide: Use struct_size() for kmalloc()-family
  device: Use overflow helpers for devm_kmalloc()
  mm: Use overflow helpers in kvmalloc()
  mm: Use overflow helpers in kmalloc_array*()
  test_overflow: Add memory allocation overflow tests
  overflow.h: Add allocation size calculation helpers
  test_overflow: Report test failures
  test_overflow: macrofy some more, do more tests for free
  lib: add runtime test of check_*_overflow functions
  compiler.h: enable builtin overflow checkers and add fallback code
2018-06-06 17:27:14 -07:00
Kees Cook
acafe7e302 treewide: Use struct_size() for kmalloc()-family
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06 11:15:43 -07:00
David Howells
1a025028d4 rxrpc: Fix handling of call quietly cancelled out on server
Sometimes an in-progress call will stop responding on the fileserver when
the fileserver quietly cancels the call with an internally marked abort
(RX_CALL_DEAD), without sending an ABORT to the client.

This causes the client's call to eventually expire from lack of incoming
packets directed its way, which currently leads to it being cancelled
locally with ETIME.  Note that it's not currently clear as to why this
happens as it's really hard to reproduce.

The rotation policy implement by kAFS, however, doesn't differentiate
between ETIME meaning we didn't get any response from the server and ETIME
meaning the call got cancelled mid-flow.  The latter leads to an oops when
fetching data as the rotation partially resets the afs_read descriptor,
which can result in a cleared page pointer being dereferenced because that
page has already been filled.

Handle this by the following means:

 (1) Set a flag on a call when we receive a packet for it.

 (2) Store the highest packet serial number so far received for a call
     (bearing in mind this may wrap).

 (3) If, when the "not received anything recently" timeout expires on a
     call, we've received at least one packet for a call and the connection
     as a whole has received packets more recently than that call, then
     cancel the call locally with ECONNRESET rather than ETIME.

     This indicates that the call was definitely in progress on the server.

 (4) In kAFS, if the rotation algorithm sees ECONNRESET rather than ETIME,
     don't try the next server, but rather abort the call.

     This avoids the oops as we don't try to reuse the afs_read struct.
     Rather, as-yet ungotten pages will be reread at a later data.

Also:

 (5) Add an rxrpc tracepoint to log detection of the call being reset.

Without this, I occasionally see an oops like the following:

    general protection fault: 0000 [#1] SMP PTI
    ...
    RIP: 0010:_copy_to_iter+0x204/0x310
    RSP: 0018:ffff8800cae0f828 EFLAGS: 00010206
    RAX: 0000000000000560 RBX: 0000000000000560 RCX: 0000000000000560
    RDX: ffff8800cae0f968 RSI: ffff8800d58b3312 RDI: 0005080000000000
    RBP: ffff8800cae0f968 R08: 0000000000000560 R09: ffff8800ca00f400
    R10: ffff8800c36f28d4 R11: 00000000000008c4 R12: ffff8800cae0f958
    R13: 0000000000000560 R14: ffff8800d58b3312 R15: 0000000000000560
    FS:  00007fdaef108080(0000) GS:ffff8800ca680000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fb28a8fa000 CR3: 00000000d2a76002 CR4: 00000000001606e0
    Call Trace:
     skb_copy_datagram_iter+0x14e/0x289
     rxrpc_recvmsg_data.isra.0+0x6f3/0xf68
     ? trace_buffer_unlock_commit_regs+0x4f/0x89
     rxrpc_kernel_recv_data+0x149/0x421
     afs_extract_data+0x1e0/0x798
     ? afs_wait_for_call_to_complete+0xc9/0x52e
     afs_deliver_fs_fetch_data+0x33a/0x5ab
     afs_deliver_to_call+0x1ee/0x5e0
     ? afs_wait_for_call_to_complete+0xc9/0x52e
     afs_wait_for_call_to_complete+0x12b/0x52e
     ? wake_up_q+0x54/0x54
     afs_make_call+0x287/0x462
     ? afs_fs_fetch_data+0x3e6/0x3ed
     ? rcu_read_lock_sched_held+0x5d/0x63
     afs_fs_fetch_data+0x3e6/0x3ed
     afs_fetch_data+0xbb/0x14a
     afs_readpages+0x317/0x40d
     __do_page_cache_readahead+0x203/0x2ba
     ? ondemand_readahead+0x3a7/0x3c1
     ondemand_readahead+0x3a7/0x3c1
     generic_file_buffered_read+0x18b/0x62f
     __vfs_read+0xdb/0xfe
     vfs_read+0xb2/0x137
     ksys_read+0x50/0x8c
     do_syscall_64+0x7d/0x1a0
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

Note the weird value in RDI which is a result of trying to kmap() a NULL
page pointer.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04 16:06:26 -04:00
Linus Torvalds
cf626b0da7 Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull procfs updates from Al Viro:
 "Christoph's proc_create_... cleanups series"

* 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (44 commits)
  xfs, proc: hide unused xfs procfs helpers
  isdn/gigaset: add back gigaset_procinfo assignment
  proc: update SIZEOF_PDE_INLINE_NAME for the new pde fields
  tty: replace ->proc_fops with ->proc_show
  ide: replace ->proc_fops with ->proc_show
  ide: remove ide_driver_proc_write
  isdn: replace ->proc_fops with ->proc_show
  atm: switch to proc_create_seq_private
  atm: simplify procfs code
  bluetooth: switch to proc_create_seq_data
  netfilter/x_tables: switch to proc_create_seq_private
  netfilter/xt_hashlimit: switch to proc_create_{seq,single}_data
  neigh: switch to proc_create_seq_data
  hostap: switch to proc_create_{seq,single}_data
  bonding: switch to proc_create_seq_data
  rtc/proc: switch to proc_create_single_data
  drbd: switch to proc_create_single
  resource: switch to proc_create_seq_data
  staging/rtl8192u: simplify procfs code
  jfs: simplify procfs code
  ...
2018-06-04 10:00:01 -07:00
Marc Dionne
1fba5868ee afs: Fix mounting of backup volumes
In theory the AFS_VLSF_BACKVOL flag for a server in a vldb entry
would indicate the presence of a backup volume on that server.

In practice however, this flag is never set, and the presence of
a backup volume is implied by the entry having AFS_VLF_BACKEXISTS set,
for the server that hosts the read-write volume (has AFS_VLSF_RWVOL).

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-16 21:35:23 +01:00
David Howells
378831e4da afs: Fix directory permissions check
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>
2018-05-16 21:35:23 +01:00
Christoph Hellwig
353861cf05 afs: simplify procfs code
Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:24:30 +02:00
David Howells
4776cab43f afs: Fix the non-encryption of calls
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>
2018-05-14 15:15:19 +01:00
David Howells
428edade4e afs: Fix CB.CallBack handling
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>
2018-05-14 15:15:19 +01:00
David Howells
68251f0a68 afs: Fix whole-volume callback handling
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>
2018-05-14 15:15:18 +01:00
Marc Dionne
f9c1bba3d3 afs: Fix afs_find_server search loop
The code that looks up servers by addresses makes the assumption
that the list of addresses for a server is sorted.  It exits the
loop if it finds that the target address is larger than the
current candidate.  As the list is not currently sorted, this
can lead to a failure to find a matching server, which can cause
callbacks from that server to be ignored.

Remove the early exit case so that the complete list is searched.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
a86b06d1cc afs: Fix the handling of an unfound server in CM operations
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>
2018-05-14 15:15:18 +01:00
David Howells
3709a399c1 afs: Add a tracepoint to record callbacks from unlisted servers
Add a tracepoint to record callbacks from servers for which we don't have a
record.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-05-14 15:15:18 +01:00
David Howells
001ab5a67e afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID
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>
2018-05-14 15:15:18 +01:00
David Howells
3d9fa91161 afs: Fix VNOVOL handling in address rotation
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>
2018-05-14 15:15:18 +01:00
David Howells
684b0f68cf afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility
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>
2018-05-14 15:15:18 +01:00
David Howells
ec5a3b4b50 afs: Fix server rotation's handling of fileserver probe failure
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>
2018-05-14 13:26:44 +01:00
David Howells
d4a96bec7a afs: Fix refcounting in callback registration
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>
2018-05-14 13:17:35 +01:00
David Howells
f2686b0926 afs: Fix giving up callbacks on server destruction
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>
2018-05-14 13:17:35 +01:00
David Howells
01fd79e6de afs: Fix address list parsing
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>
2018-05-14 13:17:35 +01:00
David Howells
b61f7dcf4e afs: Fix directory page locking
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>
2018-05-14 13:17:35 +01:00
David Howells
660625922b afs: Fix server record deletion
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>
2018-04-20 09:59:33 -07:00
Linus Torvalds
19e8a2f875 Merge branch 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro:
 "The AFS series posted by dhowells depended upon lookup_one_len()
  rework; now that prereq is in the mainline, that series had been
  rebased on top of it and got some exposure and testing..."

* 'afs-dh' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs: Do better accretion of small writes on newly created content
  afs: Add stats for data transfer operations
  afs: Trace protocol errors
  afs: Locally edit directory data for mkdir/create/unlink/...
  afs: Adjust the directory XDR structures
  afs: Split the directory content defs into a header
  afs: Fix directory handling
  afs: Split the dynroot stuff out and give it its own ops tables
  afs: Keep track of invalid-before version for dentry coherency
  afs: Rearrange status mapping
  afs: Make it possible to get the data version in readpage
  afs: Init inode before accessing cache
  afs: Introduce a statistics proc file
  afs: Dump bad status record
  afs: Implement @cell substitution handling
  afs: Implement @sys substitution handling
  afs: Prospectively look up extra files when doing a single lookup
  afs: Don't over-increment the cell usage count when pinning it
  afs: Fix checker warnings
  vfs: Remove the const from dir_context::actor
2018-04-12 11:59:06 -07:00
Matthew Wilcox
b93b016313 page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root.  Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.

[willy@infradead.org: fix nds32, fs/dax.c]
  Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
David Howells
5a81327616 afs: Do better accretion of small writes on newly created content
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>
2018-04-09 21:54:48 +01:00
David Howells
76a5cb6fc1 afs: Add stats for data transfer operations
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>
2018-04-09 21:54:48 +01:00
David Howells
5f702c8e12 afs: Trace protocol errors
Trace protocol errors detected in afs.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-09 21:54:48 +01:00
David Howells
63a4681ff3 afs: Locally edit directory data for mkdir/create/unlink/...
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>
2018-04-09 21:54:48 +01:00
David Howells
0031763698 afs: Adjust the directory XDR structures
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>
2018-04-09 21:54:48 +01:00
David Howells
4ea219a839 afs: Split the directory content defs into a header
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>
2018-04-09 21:54:48 +01:00
David Howells
f3ddee8dc4 afs: Fix directory handling
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>
2018-04-09 21:54:48 +01:00
David Howells
66c7e1d319 afs: Split the dynroot stuff out and give it its own ops tables
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>
2018-04-09 21:54:00 +01:00
David Howells
a4ff7401fb afs: Keep track of invalid-before version for dentry coherency
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>
2018-04-09 21:53:59 +01:00
David Howells
dd9fbcb8e1 afs: Rearrange status mapping
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>
2018-04-09 21:53:59 +01:00
David Howells
0c3a5ac281 afs: Make it possible to get the data version in readpage
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>
2018-04-09 21:53:56 +01:00
David Howells
5800db810a afs: Init inode before accessing cache
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>
2018-04-09 21:53:55 +01:00
David Howells
d55b4da433 afs: Introduce a statistics proc file
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>
2018-04-09 21:53:54 +01:00
David Howells
888b338461 afs: Dump bad status record
Dump an AFS FileStatus record that is detected as invalid.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-09 21:53:52 +01:00
David Howells
37ab636880 afs: Implement @cell substitution handling
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>
2018-04-09 21:18:58 +01:00
David Howells
6f8880d8e6 afs: Implement @sys substitution handling
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>
2018-04-09 21:12:31 +01:00
David Howells
5cf9dd55a0 afs: Prospectively look up extra files when doing a single lookup
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>
2018-04-09 21:12:31 +01:00
David Howells
17814aef57 afs: Don't over-increment the cell usage count when pinning it
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>
2018-04-09 21:12:31 +01:00
David Howells
fe342cf77b afs: Fix checker warnings
Fix warnings raised by checker, including:

 (*) Warnings raised by unequal comparison for the purposes of sorting,
     where the endianness doesn't matter:

fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer

 (*) afs_set_cb_interest() is not actually used and can be removed.

 (*) afs_cell_gc_delay() should be provided with a sysctl.

 (*) afs_cell_destroy() needs to use rcu_access_pointer() to read
     cell->vl_addrs.

 (*) afs_init_fs_cursor() should be static.

 (*) struct afs_vnode::permit_cache needs to be marked __rcu.

 (*) afs_server_rcu() needs to use rcu_access_pointer().

 (*) afs_destroy_server() should use rcu_access_pointer() on
     server->addresses as the server object is no longer accessible.

 (*) afs_find_server() casts __be16/__be32 values to int in order to
     directly compare them for the purpose of finding a match in a list,
     but is should also annotate the cast with __force to avoid checker
     warnings.

 (*) afs_check_permit() accesses vnode->permit_cache outside of the RCU
     readlock, though it doesn't then access the value; the extraneous
     access is deleted.

False positives:

 (*) Conditional locking around the code in xdr_decode_AFSFetchStatus.  This
     can be dealt with in a separate patch.

fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block

 (*) Incorrect handling of seq-retry lock context balance:

fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different
lock contexts for basic block
fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block
fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block

Errors:

 (*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go
     round again if it successfully found the workstation cell.

 (*) Fix UUID decode in afs_deliver_cb_probe_uuid().

 (*) afs_cache_permit() has a missing rcu_read_unlock() before one of the
     jumps to the someone_else_changed_it label.  Move the unlock to after
     the label.

 (*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when
     encoding to XDR.

 (*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl()
     when decoding from XDR.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-09 21:12:31 +01:00
David Howells
ee1235a9a0 fscache: Pass object size in rather than calling back for it
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>
2018-04-06 14:05:14 +01:00
David Howells
402cb8dda9 fscache: Attach the index key and aux data to the cookie
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>
2018-04-04 13:41:28 +01:00
David Howells
678edd09c2 afs: Be more aggressive in retiring cached vnodes
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>
2018-04-04 13:41:26 +01:00
David Howells
27a3ee3a04 afs: Use the vnode ID uniquifier in the cache key not the aux data
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>
2018-04-04 13:41:25 +01:00
David Howells
c1515999bd afs: Invalidate cache on server data change
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>
2018-04-04 13:41:25 +01:00