Drop the page lock before waiting for page writeback.

Signed-off-by: David Howells <dhowells@redhat.com>

The ->writepage() op shouldn't call clear_page_dirty_for_io() as that has
already been called by the caller.

Fix afs_writepage() by moving the call out of
afs_write_back_from_locked_page() to afs_writepages_region() where it is
needed.

Signed-off-by: David Howells <dhowells@redhat.com>

Fix the way in which a call that's in progress and being waited for is
aborted in the case that EINTR is detected.  We should be sending
RX_USER_ABORT rather than RX_CALL_DEAD as the abort code.

Note that since the only two ways out of the loop are if the call completes
or if a signal happens, the kill-the-call clause after the loop has
finished can only happen in the case of EINTR.  This means that we only
have one abort case to deal with, not two, and the "KWC" case can never
happen and so can be deleted.

Note further that simply aborting the call isn't necessarily the best thing
here since at this point: the request has been entirely sent and it's
likely the server will do the operation anyway - whether we abort it or
not.  In future, we should punt the handling of the remainder of the call
off to a background thread.

Reported-by: Marc Dionne <marc.c.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

afs_send_pages() should only put the call into the AFS_CALL_AWAIT_REPLY
state if it has sent all the pages - but the check it makes is incorrect
and sometimes it will finish the loop early.

Signed-off-by: David Howells <dhowells@redhat.com>

Fix afs_kill_pages() in two ways:

 (1) If a writeback has been partially flushed, then if we try and kill the
     pages it contains, some of them may no longer be undergoing writeback
     and end_page_writeback() will assert.

     Fix this by checking to see whether the page in question is actually
     undergoing writeback before ending that writeback.

 (2) The loop that scans for pages to kill doesn't increase the first page
     index, and so the loop may not terminate, but it will try to process
     the same pages over and over again.

     Fix this by increasing the first page index to one after the last page
     we processed.

Signed-off-by: David Howells <dhowells@redhat.com>

afs_write_begin() leaks a ref and a lock on a page if afs_fill_page()
fails.  Fix the leak by unlocking and releasing the page in the error path.

Signed-off-by: David Howells <dhowells@redhat.com>

Don't set PG_error on a page if we get local EINTR or ENOMEM when filling a
page for writing.

Signed-off-by: David Howells <dhowells@redhat.com>

The inode timestamps should be set from the client time
in the status received from the server, rather than the
server time which is meant for internal server use.

Set AFS_SET_MTIME and populate the mtime for operations
that take an input status, such as file/dir creation
and StoreData.  If an input time is not provided the
server will set the vnode times based on the current server
time.

In a situation where the server has some skew with the
client, this could lead to the client seeing a timestamp
in the future for a file that it just created or wrote.

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

If we receive a network error, a remote abort or a protocol error whilst
we're still transmitting data, make sure we return an appropriate error to
the caller rather than ESHUTDOWN or ECONNABORTED.

Signed-off-by: David Howells <dhowells@redhat.com>

When we are given an invalid operation ID, we should abort that with
RXGEN_OPCODE rather than RX_INVALID_OPERATION.

Also map RXGEN_OPCODE to -ENOTSUPP.

Signed-off-by: David Howells <dhowells@redhat.com>