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  1. Oct 24, 2018
    • David Howells's avatar
      afs: Handle EIO from delivery function · 4ac15ea5
      David Howells authored 
      Fix afs_deliver_to_call() to handle -EIO being returned by the operation
delivery function, indicating that the call found itself in the wrong
state, by printing an error and aborting the call.

Currently, an assertion failure will occur.  This can happen, say, if the
delivery function falls off the end without calling afs_extract_data() with
the want_more parameter set to false to collect the end of the Rx phase of
a call.

The assertion failure looks like:

	AFS: Assertion failed
	4 == 7 is false
	0x4 == 0x7 is false
	------------[ cut here ]------------
	kernel BUG at fs/afs/rxrpc.c:462!

and is matched in the trace buffer by a line like:

kworker/7:3-3226 [007] ...1 85158.030203: afs_io_error: c=0003be0c r=-5 CM_REPLY

Fixes: 98bf40cd

 ("afs: Protect call->state changes against signals")
Reported-by: default avatarMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      4ac15ea5
    • David Howells's avatar
      afs: Fix TTL on VL server and address lists · ded2f4c5
      David Howells authored 
      

Currently the TTL on VL server and address lists isn't set in all
circumstances and may be set to poor choices in others, since the TTL is
derived from the SRV/AFSDB DNS record if and when available.

Fix the TTL by limiting the range to a minimum and maximum from the current
time.  At some point these can be made into sysctl knobs.  Further, use the
TTL we obtained from the upcall to set the expiry on negative results too;
in future a mechanism can be added to force reloading of such data.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      ded2f4c5
    • David Howells's avatar
      afs: Implement VL server rotation · 0a5143f2
      David Howells authored 
      

Track VL servers as independent entities rather than lumping all their
addresses together into one set and implement server-level rotation by:

 (1) Add the concept of a VL server list, where each server has its own
     separate address list.  This code is similar to the FS server list.

 (2) Use the DNS resolver to retrieve a set of servers and their associated
     addresses, ports, preference and weight ratings.

 (3) In the case of a legacy DNS resolver or an address list given directly
     through /proc/net/afs/cells, create a list containing just a dummy
     server record and attach all the addresses to that.

 (4) Implement a simple rotation policy, for the moment ignoring the
     priorities and weights assigned to the servers.

 (5) Show the address list through /proc/net/afs/<cell>/vlservers.  This
     also displays the source and status of the data as indicated by the
     upcall.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      0a5143f2
    • David Howells's avatar
      afs: Improve FS server rotation error handling · e7f680f4
      David Howells authored 
      Improve the error handling in FS server rotation by:

 (1) Cache the latest useful error value for the fs operation as a whole in
     struct afs_fs_cursor separately from the error cached in the
     afs_addr_cursor struct.  The one in the address cursor gets clobbered
     occasionally.  Copy over the error to the fs operation only when it's
     something we'd be interested in passing to userspace.

 (2) Make it so that EDESTADDRREQ is the default that is seen only if no
     addresses are available to be accessed.

 (3) When calling utility functions, such as checking a volume status or
     probing a fileserver, don't let a successful result clobber the cached
     error in the cursor; instead, stash the result in a temporary variable
     until it has been assessed.

 (4) Don't return ETIMEDOUT or ETIME if a better error, such as
     ENETUNREACH, is already cached.

 (5) On leaving the rotation loop, turn any remote abort code into a more
     useful error than ECONNABORTED.

Fixes: d2ddc776

 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      e7f680f4
    • David Howells's avatar
      afs: Set up the iov_iter before calling afs_extract_data() · 12bdcf33
      David Howells authored 
      

afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.

Instead:

 (1) Put an iterator in the afs_call struct.

 (2) Set the iterator for each marshalling stage to load data into the
     appropriate places.  A number of convenience functions are provided to
     this end (eg. afs_extract_to_buf()).

     This iterator is then passed to afs_extract_data().

 (3) Use the new ITER_DISCARD iterator to discard any excess data provided
     by FetchData.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      12bdcf33
    • David Howells's avatar
      afs: Better tracing of protocol errors · 160cb957
      David Howells authored 
      

Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      160cb957
    • David Howells's avatar
      iov_iter: Add I/O discard iterator · 9ea9ce04
      David Howells authored 
      

Add a new iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it.

This is useful in a network filesystem for discarding any unwanted data
sent by a server.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      9ea9ce04
    • David Howells's avatar
      iov_iter: Separate type from direction and use accessor functions · aa563d7b
      David Howells authored 
      

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      aa563d7b
    • David Howells's avatar
      iov_iter: Use accessor function · 00e23707
      David Howells authored 
      

Use accessor functions to access an iterator's type and direction.  This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      00e23707
    • David Howells's avatar
      amd-gpu: Don't undefine READ and WRITE · 1fcb748d
      David Howells authored 
      Remove the undefinition of READ and WRITE because these constants may be
used elsewhere in subsequently included header files, thus breaking them.

These constants don't actually appear to be used in the driver, so the
undefinition seems pointless.

Fixes: 4562236b

 ("drm/amd/dc: Add dc display driver (v2)")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      1fcb748d
  3. Oct 20, 2018
  5. Oct 19, 2018