1. 11 2月, 2017 1 次提交
  2. 09 1月, 2017 2 次提交
    • D
      afs: Refcount the afs_call struct · 341f741f
      David Howells 提交于
      A static checker warning occurs in the AFS filesystem:
      
      	fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
      	error: dereferencing freed memory 'call'
      
      due to the reply being sent before we access the server it points to.  The
      act of sending the reply causes the call to be freed if an error occurs
      (but not if it doesn't).
      
      On top of this, the lifetime handling of afs_call structs is fragile
      because they get passed around through workqueues without any sort of
      refcounting.
      
      Deal with the issues by:
      
       (1) Fix the maybe/maybe not nature of the reply sending functions with
           regards to whether they release the call struct.
      
       (2) Refcount the afs_call struct and sort out places that need to get/put
           references.
      
       (3) Pass a ref through the work queue and release (or pass on) that ref in
           the work function.  Care has to be taken because a work queue may
           already own a ref to the call.
      
       (4) Do the cleaning up in the put function only.
      
       (5) Simplify module cleanup by always incrementing afs_outstanding_calls
           whenever a call is allocated.
      
       (6) Set the backlog to 0 with kernel_listen() at the beginning of the
           process of closing the socket to prevent new incoming calls from
           occurring and to remove the contribution of preallocated calls from
           afs_outstanding_calls before we wait on it.
      
      A tracepoint is also added to monitor the afs_call refcount and lifetime.
      Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Fixes: 08e0e7c8: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC."
      341f741f
    • D
      afs: Add some tracepoints · 8e8d7f13
      David Howells 提交于
      Add three tracepoints to the AFS filesystem:
      
       (1) The afs_recv_data tracepoint logs data segments that are extracted
           from the data received from the peer through afs_extract_data().
      
       (2) The afs_notify_call tracepoint logs notification from AF_RXRPC of data
           coming in to an asynchronous call.
      
       (3) The afs_cb_call tracepoint logs incoming calls that have had their
           operation ID extracted and mapped into a supported cache manager
           service call.
      
      To make (3) work, the name strings in the afs_call_type struct objects have
      to be annotated with __tracepoint_string.  This is done with the CM_NAME()
      macro.
      
      Further, the AFS call state enum needs a name so that it can be used to
      declare parameter types.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      8e8d7f13
  3. 14 10月, 2016 1 次提交
  4. 02 9月, 2016 1 次提交
    • D
      rxrpc: Don't expose skbs to in-kernel users [ver #2] · d001648e
      David Howells 提交于
      Don't expose skbs to in-kernel users, such as the AFS filesystem, but
      instead provide a notification hook the indicates that a call needs
      attention and another that indicates that there's a new call to be
      collected.
      
      This makes the following possibilities more achievable:
      
       (1) Call refcounting can be made simpler if skbs don't hold refs to calls.
      
       (2) skbs referring to non-data events will be able to be freed much sooner
           rather than being queued for AFS to pick up as rxrpc_kernel_recv_data
           will be able to consult the call state.
      
       (3) We can shortcut the receive phase when a call is remotely aborted
           because we don't have to go through all the packets to get to the one
           cancelling the operation.
      
       (4) It makes it easier to do encryption/decryption directly between AFS's
           buffers and sk_buffs.
      
       (5) Encryption/decryption can more easily be done in the AFS's thread
           contexts - usually that of the userspace process that issued a syscall
           - rather than in one of rxrpc's background threads on a workqueue.
      
       (6) AFS will be able to wait synchronously on a call inside AF_RXRPC.
      
      To make this work, the following interface function has been added:
      
           int rxrpc_kernel_recv_data(
      		struct socket *sock, struct rxrpc_call *call,
      		void *buffer, size_t bufsize, size_t *_offset,
      		bool want_more, u32 *_abort_code);
      
      This is the recvmsg equivalent.  It allows the caller to find out about the
      state of a specific call and to transfer received data into a buffer
      piecemeal.
      
      afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction
      logic between them.  They don't wait synchronously yet because the socket
      lock needs to be dealt with.
      
      Five interface functions have been removed:
      
      	rxrpc_kernel_is_data_last()
          	rxrpc_kernel_get_abort_code()
          	rxrpc_kernel_get_error_number()
          	rxrpc_kernel_free_skb()
          	rxrpc_kernel_data_consumed()
      
      As a temporary hack, sk_buffs going to an in-kernel call are queued on the
      rxrpc_call struct (->knlrecv_queue) rather than being handed over to the
      in-kernel user.  To process the queue internally, a temporary function,
      temp_deliver_data() has been added.  This will be replaced with common code
      between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a
      future patch.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d001648e
  5. 30 8月, 2016 2 次提交
  6. 06 8月, 2016 1 次提交
    • D
      rxrpc: Fix races between skb free, ACK generation and replying · 372ee163
      David Howells 提交于
      Inside the kafs filesystem it is possible to occasionally have a call
      processed and terminated before we've had a chance to check whether we need
      to clean up the rx queue for that call because afs_send_simple_reply() ends
      the call when it is done, but this is done in a workqueue item that might
      happen to run to completion before afs_deliver_to_call() completes.
      
      Further, it is possible for rxrpc_kernel_send_data() to be called to send a
      reply before the last request-phase data skb is released.  The rxrpc skb
      destructor is where the ACK processing is done and the call state is
      advanced upon release of the last skb.  ACK generation is also deferred to
      a work item because it's possible that the skb destructor is not called in
      a context where kernel_sendmsg() can be invoked.
      
      To this end, the following changes are made:
      
       (1) kernel_rxrpc_data_consumed() is added.  This should be called whenever
           an skb is emptied so as to crank the ACK and call states.  This does
           not release the skb, however.  kernel_rxrpc_free_skb() must now be
           called to achieve that.  These together replace
           rxrpc_kernel_data_delivered().
      
       (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed().
      
           This makes afs_deliver_to_call() easier to work as the skb can simply
           be discarded unconditionally here without trying to work out what the
           return value of the ->deliver() function means.
      
           The ->deliver() functions can, via afs_data_complete(),
           afs_transfer_reply() and afs_extract_data() mark that an skb has been
           consumed (thereby cranking the state) without the need to
           conditionally free the skb to make sure the state is correct on an
           incoming call for when the call processor tries to send the reply.
      
       (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it
           has finished with a packet and MSG_PEEK isn't set.
      
       (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data().
      
           Because of this, we no longer need to clear the destructor and put the
           call before we free the skb in cases where we don't want the ACK/call
           state to be cranked.
      
       (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather
           than 0 if they expect more data (afs_extract_data() returns -EAGAIN to
           the delivery function already), and the caller is now responsible for
           producing an abort if that was the last packet.
      
       (6) There are many bits of unmarshalling code where:
      
       		ret = afs_extract_data(call, skb, last, ...);
      		switch (ret) {
      		case 0:		break;
      		case -EAGAIN:	return 0;
      		default:	return ret;
      		}
      
           is to be found.  As -EAGAIN can now be passed back to the caller, we
           now just return if ret < 0:
      
       		ret = afs_extract_data(call, skb, last, ...);
      		if (ret < 0)
      			return ret;
      
       (7) Checks for trailing data and empty final data packets has been
           consolidated as afs_data_complete().  So:
      
      		if (skb->len > 0)
      			return -EBADMSG;
      		if (!last)
      			return 0;
      
           becomes:
      
      		ret = afs_data_complete(call, skb, last);
      		if (ret < 0)
      			return ret;
      
       (8) afs_transfer_reply() now checks the amount of data it has against the
           amount of data desired and the amount of data in the skb and returns
           an error to induce an abort if we don't get exactly what we want.
      
      Without these changes, the following oops can occasionally be observed,
      particularly if some printks are inserted into the delivery path:
      
      general protection fault: 0000 [#1] SMP
      Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
      CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G            E   4.7.0-fsdevel+ #1303
      Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
      Workqueue: kafsd afs_async_workfn [kafs]
      task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000
      RIP: 0010:[<ffffffff8108fd3c>]  [<ffffffff8108fd3c>] __lock_acquire+0xcf/0x15a1
      RSP: 0018:ffff88040c073bc0  EFLAGS: 00010002
      RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710
      RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710
      RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001
      R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
      R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f
      FS:  0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0
      Stack:
       0000000000000006 000000000be04930 0000000000000000 ffff880400000000
       ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446
       ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38
      Call Trace:
       [<ffffffff8108f847>] ? mark_held_locks+0x5e/0x74
       [<ffffffff81050446>] ? __local_bh_enable_ip+0x9b/0xa1
       [<ffffffff8108f9ca>] ? trace_hardirqs_on_caller+0x16d/0x189
       [<ffffffff810915f4>] lock_acquire+0x122/0x1b6
       [<ffffffff810915f4>] ? lock_acquire+0x122/0x1b6
       [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
       [<ffffffff81609dbf>] _raw_spin_lock_irqsave+0x35/0x49
       [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
       [<ffffffff814c928f>] skb_dequeue+0x18/0x61
       [<ffffffffa009aa92>] afs_deliver_to_call+0x344/0x39d [kafs]
       [<ffffffffa009ab37>] afs_process_async_call+0x4c/0xd5 [kafs]
       [<ffffffffa0099e9c>] afs_async_workfn+0xe/0x10 [kafs]
       [<ffffffff81063a3a>] process_one_work+0x29d/0x57c
       [<ffffffff81064ac2>] worker_thread+0x24a/0x385
       [<ffffffff81064878>] ? rescuer_thread+0x2d0/0x2d0
       [<ffffffff810696f5>] kthread+0xf3/0xfb
       [<ffffffff8160a6ff>] ret_from_fork+0x1f/0x40
       [<ffffffff81069602>] ? kthread_create_on_node+0x1cf/0x1cf
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      372ee163
  7. 21 5月, 2014 1 次提交
    • D
      AFS: Fix cache manager service handlers · 6c67c7c3
      David Howells 提交于
      Fix the cache manager RPC service handlers.  The afs_send_empty_reply() and
      afs_send_simple_reply() functions:
      
       (a) Kill the call and free up the buffers associated with it if they fail.
      
       (b) Return with call intact if it they succeed.
      
      However, none of the callers actually check the result or clean up if
      successful - and may use the now non-existent data if it fails.
      
      This was detected by Dan Carpenter using a static checker:
      
      	The patch 08e0e7c8: "[AF_RXRPC]: Make the in-kernel AFS
      	filesystem use AF_RXRPC." from Apr 26, 2007, leads to the following
      	static checker warning:
      	"fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
      		 warn: 'call' was already freed."
      Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      6c67c7c3
  8. 15 1月, 2011 1 次提交
  9. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  10. 29 4月, 2008 2 次提交
  11. 17 10月, 2007 1 次提交
    • A
      fs/afs/: possible cleanups · c1206a2c
      Adrian Bunk 提交于
      This patch contains the following possible cleanups:
      - make the following needlessly global functions static:
        - rxrpc.c: afs_send_pages()
        - vlocation.c: afs_vlocation_queue_for_updates()
        - write.c: afs_writepages_region()
      - make the following needlessly global variables static:
        - mntpt.c: afs_mntpt_expiry_timeout
        - proc.c: afs_vlocation_states[]
        - server.c: afs_server_timeout
        - vlocation.c: afs_vlocation_timeout
        - vlocation.c: afs_vlocation_update_timeout
      - #if 0 the following unused function:
        - cell.c: afs_get_cell_maybe()
      - #if 0 the following unused variables:
        - callback.c: afs_vnode_update_timeout
        - cmservice.c: struct afs_cm_workqueue
      Signed-off-by: NAdrian Bunk <bunk@stusta.de>
      Acked-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c1206a2c
  12. 03 5月, 2007 1 次提交
  13. 27 4月, 2007 5 次提交
  14. 24 3月, 2006 1 次提交
  15. 11 1月, 2006 1 次提交
  16. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4