YFS VL servers offer an upgraded Volume Location service that can return
IPv6 addresses to fileservers and volume servers in addition to IPv4
addresses using the YFSVL.GetEndpoints operation which we should use if
it's available.

To this end:

 (1) Make rxrpc_kernel_recv_data() return the call's current service ID so
     that the caller can detect service upgrade and see what the service
     was upgraded to.

 (2) When we see a VL server address we haven't seen before, send a
     VL.GetCapabilities operation to it with the service upgrade bit set.

     If we get an upgrade to the YFS VL service, change the service ID in
     the address list for that address to use the upgraded service and set
     a flag to note that this appears to be a YFS-compatible server.

 (3) If, when a server's addresses are being looked up, we note that we
     previously detected a YFS-compatible server, then send the
     YFSVL.GetEndpoints operation rather than VL.GetAddrsU.

 (4) Build a fileserver address list from the reply of YFSVL.GetEndpoints,
     including both IPv4 and IPv6 addresses.  Volume server addresses are
     discarded.

 (5) The address list is sorted by address and port now, instead of just
     address.  This allows multiple servers on the same host sitting on
     different ports.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The current code assumes that volumes and servers are per-cell and are
never shared, but this is not enforced, and, indeed, public cells do exist
that are aliases of each other.  Further, an organisation can, say, set up
a public cell and a private cell with overlapping, but not identical, sets
of servers.  The difference is purely in the database attached to the VL
servers.

The current code will malfunction if it sees a server in two cells as it
assumes global address -> server record mappings and that each server is in
just one cell.

Further, each server may have multiple addresses - and may have addresses
of different families (IPv4 and IPv6, say).

To this end, the following structural changes are made:

 (1) Server record management is overhauled:

     (a) Server records are made independent of cell.  The namespace keeps
     	 track of them, volume records have lists of them and each vnode
     	 has a server on which its callback interest currently resides.

     (b) The cell record no longer keeps a list of servers known to be in
     	 that cell.

     (c) The server records are now kept in a flat list because there's no
     	 single address to sort on.

     (d) Server records are now keyed by their UUID within the namespace.

     (e) The addresses for a server are obtained with the VL.GetAddrsU
     	 rather than with VL.GetEntryByName, using the server's UUID as a
     	 parameter.

     (f) Cached server records are garbage collected after a period of
     	 non-use and are counted out of existence before purging is allowed
     	 to complete.  This protects the work functions against rmmod.

     (g) The servers list is now in /proc/fs/afs/servers.

 (2) Volume record management is overhauled:

     (a) An RCU-replaceable server list is introduced.  This tracks both
     	 servers and their coresponding callback interests.

     (b) The superblock is now keyed on cell record and numeric volume ID.

     (c) The volume record is now tied to the superblock which mounts it,
     	 and is activated when mounted and deactivated when unmounted.
     	 This makes it easier to handle the cache cookie without causing a
     	 double-use in fscache.

     (d) The volume record is loaded from the VLDB using VL.GetEntryByNameU
     	 to get the server UUID list.

     (e) The volume name is updated if it is seen to have changed when the
     	 volume is updated (the update is keyed on the volume ID).

 (3) The vlocation record is got rid of and VLDB records are no longer
     cached.  Sufficient information is stored in the volume record, though
     an update to a volume record is now no longer shared between related
     volumes (volumes come in bundles of three: R/W, R/O and backup).

and the following procedural changes are made:

 (1) The fileserver cursor introduced previously is now fleshed out and
     used to iterate over fileservers and their addresses.

 (2) Volume status is checked during iteration, and the server list is
     replaced if a change is detected.

 (3) Server status is checked during iteration, and the address list is
     replaced if a change is detected.

 (4) The abort code is saved into the address list cursor and -ECONNABORTED
     returned in afs_make_call() if a remote abort happened rather than
     translating the abort into an error message.  This allows actions to
     be taken depending on the abort code more easily.

     (a) If a VMOVED abort is seen then this is handled by rechecking the
     	 volume and restarting the iteration.

     (b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is
         handled by sleeping for a short period and retrying and/or trying
         other servers that might serve that volume.  A message is also
         displayed once until the condition has cleared.

     (c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the
     	 moment.

     (d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to
     	 see if it has been deleted; if not, the fileserver is probably
     	 indicating that the volume couldn't be attached and needs
     	 salvaging.

     (e) If statfs() sees one of these aborts, it does not sleep, but
     	 rather returns an error, so as not to block the umount program.

 (5) The fileserver iteration functions in vnode.c are now merged into
     their callers and more heavily macroised around the cursor.  vnode.c
     is removed.

 (6) Operations on a particular vnode are serialised on that vnode because
     the server will lock that vnode whilst it operates on it, so a second
     op sent will just have to wait.

 (7) Fileservers are probed with FS.GetCapabilities before being used.
     This is where service upgrade will be done.

 (8) A callback interest on a fileserver is set up before an FS operation
     is performed and passed through to afs_make_call() so that it can be
     set on the vnode if the operation returns a callback.  The callback
     interest is passed through to afs_iget() also so that it can be set
     there too.

In general, record updating is done on an as-needed basis when we try to
access servers, volumes or vnodes rather than offloading it to work items
and special threads.

Notes:

 (1) Pre AFS-3.4 servers are no longer supported, though this can be added
     back if necessary (AFS-3.4 was released in 1998).

 (2) VBUSY is retried forever for the moment at intervals of 1s.

 (3) /proc/fs/afs/<cell>/servers no longer exists.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Move server rotation code into its own file.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add an RCU replaceable address list structure to hold a list of server
addresses.  The list also holds the

To this end:

 (1) A cell's VL server address list can be loaded directly via insmod or
     echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB
     or SRV records.

 (2) Anyone wanting to use a cell's VL server address must wait until the
     cell record comes online and has tried to obtain some addresses.

 (3) An FS server's address list, for the moment, has a single entry that
     is the key to the server list.  This will change in the future when a
     server is instead keyed on its UUID and the VL.GetAddrsU operation is
     used.

 (4) An 'address cursor' concept is introduced to handle iteration through
     the address list.  This is passed to the afs_make_call() as, in the
     future, stuff (such as abort code) that doesn't outlast the call will
     be returned in it.

In the future, we might want to annotate the list with information about
how each address fares.  We might then want to propagate such annotations
over address list replacement.

Whilst we're at it, we allow IPv6 addresses to be specified in
colon-delimited lists by enclosing them in square brackets.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Overhaul the way that the in-kernel AFS client keeps track of cells in the
following manner:

 (1) Cells are now held in an rbtree to make walking them quicker and RCU
     managed (though this is probably overkill).

 (2) Cells now have a manager work item that:

     (A) Looks after fetching and refreshing the VL server list.

     (B) Manages cell record lifetime, including initialising and
     	 destruction.

     (B) Manages cell record caching whereby threads are kept around for a
     	 certain time after last use and then destroyed.

     (C) Manages the FS-Cache index cookie for a cell.  It is not permitted
     	 for a cookie to be in use twice, so we have to be careful to not
     	 allow a new cell record to exist at the same time as an old record
     	 of the same name.

 (3) Each AFS network namespace is given a manager work item that manages
     the cells within it, maintaining a single timer to prod cells into
     updating their DNS records.

     This uses the reduce_timer() facility to make the timer expire at the
     soonest timed event that needs happening.

 (4) When a module is being unloaded, cells and cell managers are now
     counted out using dec_after_work() to make sure the module text is
     pinned until after the data structures have been cleaned up.

 (5) Each cell's VL server list is now protected by a seqlock rather than a
     semaphore.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.

When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation.  This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file).  This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.

With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer.  This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.

Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.

Note that that table is global rather than being per-net_ns.  If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.

Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer.  In such an event, memory barriers will need adding.

Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Overhaul the AFS callback handling by the following means:

 (1) Don't give up callback promises on vnodes that we are no longer using,
     rather let them just expire on the server or let the server break
     them.  This is actually more efficient for the server as the callback
     lookup is expensive if there are lots of extant callbacks.

 (2) Only give up the callback promises we have from a server when the
     server record is destroyed.  Then we can just give up *all* the
     callback promises on it in one go.

 (3) Servers can end up being shared between cells if cells are aliased, so
     don't add all the vnodes being backed by a particular server into a
     big FID-indexed tree on that server as there may be duplicates.

     Instead have each volume instance (~= superblock) register an interest
     in a server as it starts to make use of it and use this to allow the
     processor for callbacks from the server to find the superblock and
     thence the inode corresponding to the FID being broken by means of
     ilookup_nowait().

 (4) Rather than iterating over the entire callback list when a mass-break
     comes in from the server, maintain a counter of mass-breaks in
     afs_server (cb_seq) and make afs_validate() check it against the copy
     in afs_vnode.

     It would be nice not to have to take a read_lock whilst doing this,
     but that's tricky without using RCU.

 (5) Save a ref on the fileserver we're using for a call in the afs_call
     struct so that we can access its cb_s_break during call decoding.

 (6) Write-lock around callback and status storage in a vnode and read-lock
     around getattr so that we don't see the status mid-update.

This has the following consequences:

 (1) Data invalidation isn't seen until someone calls afs_validate() on a
     vnode.  Unfortunately, we need to use a key to query the server, but
     getting one from a background thread is tricky without caching loads
     of keys all over the place.

 (2) Mass invalidation isn't seen until someone calls afs_validate().

 (3) Callback breaking is going to hit the inode_hash_lock quite a bit.
     Could this be replaced with rcu_read_lock() since inodes are destroyed
     under RCU conditions.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Rename the server member of struct afs_call to cm_server as we're only
going to be using it for incoming calls for the Cache Manager service.
This makes it easier to differentiate from the pointer to the target server
for the client, which will point to a different structure to allow for
callback handling.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

In AFS's encoding of a UUID, the eight 'char' fields are all signed, so
represent them with __s8 rather than __u8.  This makes the compiler
sign-extend them correctly when XDR-encoding them.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The handler for the CB.ProbeUuid operation in the cache manager is
implemented, but isn't listed in the switch-statement of operation
selection, so won't be used.  Fix this by adding it.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

If call->ret_reply0 is set, return call->reply[0] on success.  Change the
return type of afs_make_call() to long so that this can be passed back
without bit loss and then cast to a pointer if required.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Condense struct afs_call's reply anchor members - reply{,2,3,4} - into an
array.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The AFS abort code space is shared across all services, so there's no need
for separate abort_to_error translators for each service.

Consolidate them into a single function and remove the function pointers
for them.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Allow VL server specifications to be given IPv6 addresses as well as IPv4
addresses, for example as:

	echo add foo.org 1111:2222:3333:0:4444:5555:6666:7777 >/proc/fs/afs/cells

Note that ':' is the expected separator for separating IPv4 addresses, but
if a ',' is detected or no '.' is detected in the string, the delimiter is
switched to ','.

This also works with DNS AFSDB or SRV record strings fetched by upcall from
userspace.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Keep and pass sockaddr_rxrpc addresses around rather than keeping and
passing in_addr addresses to allow for the use of IPv6 and non-standard
port numbers in future.

This also allows the port and service_id fields to be removed from the
afs_call struct.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Update the cache index structure in the following ways:

 (1) Don't use the volume name followed by the volume type as levels in the
     cache index.  Volumes can be renamed.  Use the volume ID instead.

 (2) Don't store the VLDB data for a volume in the tree.  If the volume
     database should be cached locally, then it should be done in a separate
     tree.

 (3) Expand the volume ID stored in the cache to 64 bits.

 (4) Expand the file/vnode ID stored in the cache to 96 bits.

 (5) Increment the cache structure version number to 1.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add some protocol definitions, including max field lengths, flag defs, an
XDR-encoded UUID def, more VL operation IDs and more fileserver abort
codes.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Push the network namespace pointer to more places in AFS, including the
afs_server structure (which doesn't hold a ref on the netns).

In particular, afs_put_cell() now takes requires a net ns parameter so that
it can safely alter the netns after decrementing the cell usage count - the
cell will be deallocated by a background thread after being cached for a
period, which means that it's not safe to access it after reducing its
usage count.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Keep a reference to the cell in the superblock info structure in addition
to the volume and net pointers.  This will make it easier to clean up in a
future patch in which afs_put_volume() will need the cell pointer.

Whilst we're at it, make the cell and volume getting functions return a
pointer to the object got to make the call sites look neater.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix server reaping and make sure it's all done before we start trying to
purge cells, given that servers currently pin cells.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Close the rxrpc socket only after we've purged the server records (and also
cell and volume records which might refer to servers) so that we can give
up the callbacks on each server.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Lay the groundwork for supporting network namespaces (netns) to the AFS
filesystem by moving various global features to a network-namespace struct
(afs_net) and providing an instance of this as a temporary global variable
that everything uses via accessor functions for the moment.

The following changes have been made:

 (1) Store the netns in the superblock info.  This will be obtained from
     the mounter's nsproxy on a manual mount and inherited from the parent
     superblock on an automount.

 (2) The cell list is made per-netns.  It can be viewed through
     /proc/net/afs/cells and also be modified by writing commands to that
     file.

 (3) The local workstation cell is set per-ns in /proc/net/afs/rootcell.
     This is unset by default.

 (4) The 'rootcell' module parameter, which sets a cell and VL server list
     modifies the init net namespace, thereby allowing an AFS root fs to be
     theoretically used.

 (5) The volume location lists and the file lock manager are made
     per-netns.

 (6) The AF_RXRPC socket and associated I/O bits are made per-ns.

The various workqueues remain global for the moment.

Changes still to be made:

 (1) /proc/fs/afs/ should be moved to /proc/net/afs/ and a symlink emplaced
     from the old name.

 (2) A per-netns subsys needs to be registered for AFS into which it can
     store its per-netns data.

 (3) Rather than the AF_RXRPC socket being opened on module init, it needs
     to be opened on the creation of a superblock in that netns.

 (4) The socket needs to be closed when the last superblock using it is
     destroyed and all outstanding client calls on it have been completed.
     This prevents a reference loop on the namespace.

 (5) It is possible that several namespaces will want to use AFS, in which
     case each one will need its own UDP port.  These can either be set
     through /proc/net/afs/cm_port or the kernel can pick one at random.
     The init_ns gets 7001 by default.

Other issues that need resolving:

 (1) The DNS keyring needs net-namespacing.

 (2) Where do upcalls go (eg. DNS request-key upcall)?

 (3) Need something like open_socket_in_file_ns() syscall so that AFS
     command line tools attempting to operate on an AFS file/volume have
     their RPC calls go to the right place.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Make wait_on_atomic_t() pass the TASK_* mode onto its action function as an
extra argument and make it 'unsigned int throughout.

Also, consolidate a bunch of identical action functions into a default
function that can do the appropriate thing for the mode.

Also, change the argument name in the bit_wait*() function declarations to
reflect the fact that it's the mode and not the bit number.

[Peter Z gives this a grudging ACK, but thinks that the whole atomic_t wait
should be done differently, though he's not immediately sure as to how]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
cc: Ingo Molnar <mingo@kernel.org>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make AF_RXRPC accept MSG_WAITALL as a flag to sendmsg() to tell it to
ignore signals whilst loading up the message queue, provided progress is
being made in emptying the queue at the other side.

Progress is defined as the base of the transmit window having being
advanced within 2 RTT periods.  If the period is exceeded with no progress,
sendmsg() will return anyway, indicating how much data has been copied, if
any.

Once the supplied buffer is entirely decanted, the sendmsg() will return.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Provide support for a kernel service to make use of the service upgrade
facility.  This involves:

 (1) Pass an upgrade request flag to rxrpc_kernel_begin_call().

 (2) Make rxrpc_kernel_recv_data() return the call's current service ID so
     that the caller can detect service upgrade and see what the service
     was upgraded to.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Patch series "Ranged pagevec lookup", v2.

In this series I make pagevec_lookup() update the index (to be
consistent with pagevec_lookup_tag() and also as a preparation for
ranged lookups), provide ranged variant of pagevec_lookup() and use it
in places where it makes sense.  This not only removes some common code
but is also a measurable performance win for some use cases (see patch
4/10) where radix tree is sparse and searching & grabing of a page after
the end of the range has measurable overhead.

This patch (of 10):

The callback doesn't ever get called.  Remove it.

Link: http://lkml.kernel.org/r/20170726114704.7626-2-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a callback to rxrpc_kernel_send_data() so that a kernel service can get
a notification that the AF_RXRPC call has transitioned out the Tx phase and
is now waiting for a reply or a final ACK.

This is called from AF_RXRPC with the call state lock held so the
notification is guaranteed to come before any reply is passed back.

Further, modify the AFS filesystem to make use of this so that we don't have
to change the afs_call state before sending the last bit of data.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

This patch converts most of the in-kernel filesystems that do writeback
out of the pagecache to report errors using the errseq_t-based
infrastructure that was recently added. This allows them to report
errors once for each open file description.

Most filesystems have a fairly straightforward fsync operation. They
call filemap_write_and_wait_range to write back all of the data and
wait on it, and then (sometimes) sync out the metadata.

For those filesystems this is a straightforward conversion from calling
filemap_write_and_wait_range in their fsync operation to calling
file_write_and_wait_range.
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: NDave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Move the protocol description header file into net/rxrpc/ and rename it to
protocol.h.  It's no longer necessary to expose it as packets are no longer
exposed to kernel services (such as AFS) that use the facility.

The abort codes are transferred to the UAPI header instead as we pass these
back to userspace and also to kernel services.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Implement the show_options superblock op for afs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Also implement the show_devname op to display the correct device name and thus
avoid the need to display the cell= and volume= options.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add xattrs to allow the user to get/set metadata in lieu of having pioctl()
available.  The following xattrs are now available:

 - "afs.cell"

   The name of the cell in which the vnode's volume resides.

 - "afs.fid"

   The volume ID, vnode ID and vnode uniquifier of the file as three hex
   numbers separated by colons.

 - "afs.volume"

   The name of the volume in which the vnode resides.

For example:

	# getfattr -d -m ".*" /mnt/scratch
	getfattr: Removing leading '/' from absolute path names
	# file: mnt/scratch
	afs.cell="mycell.myorg.org"
	afs.fid="10000b:1:1"
	afs.volume="scratch"
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The AFS_ACE_READ and AFS_ACE_WRITE permission bits should not
be used to make access decisions for the directory itself.  They
are meant to control access for the objects contained in that
directory.

Reading a directory is allowed if the AFS_ACE_LOOKUP bit is set.
This would cause an incorrect access denied error for a directory
with AFS_ACE_LOOKUP but not AFS_ACE_READ.

The AFS_ACE_WRITE bit does not allow operations that modify the
directory.  For a directory with AFS_ACE_WRITE but neither
AFS_ACE_INSERT nor AFS_ACE_DELETE, this would result in trying
operations that would ultimately be denied by the server.
Signed-off-by: NMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

This essentially is a partial revert of commit ff548773
("afs: Move UUID struct to linux/uuid.h") and moves struct uuid_v1 back into
fs/afs as struct afs_uuid.  It however keeps it as big endian structure
so that we can use the normal uuid generation helpers when casting to/from
struct afs_uuid.

The V1 uuid intrepretation in struct form isn't really useful to the
rest of the kernel, and not really compatible to it either, so move it
back to AFS instead of polluting the global uuid.h.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDavid Howells <dhowells@redhat.com>

Allocate struct backing_dev_info separately instead of embedding it
inside the superblock. This unifies handling of bdi among users.

CC: David Howells <dhowells@redhat.com>
CC: linux-afs@lists.infradead.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Use negative error codes in struct rxrpc_call::error because that's what
the kernel normally deals with and to make the code consistent.  We only
turn them positive when transcribing into a cmsg for userspace recvmsg.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Drop the page lock before waiting for page writeback.
Signed-off-by: NDavid 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: NDavid 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: NMarc Dionne <marc.c.dionne@auristor.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>