Commit Graph

653 Commits

Author SHA1 Message Date
David Howells
a58823ac45 afs: Fix application of status and callback to be under same lock
When applying the status and callback in the response of an operation,
apply them in the same critical section so that there's no race between
checking the callback state and checking status-dependent state (such as
the data version).

Fix this by:

 (1) Allocating a joint {status,callback} record (afs_status_cb) before
     calling the RPC function for each vnode for which the RPC reply
     contains a status or a status plus a callback.  A flag is set in the
     record to indicate if a callback was actually received.

 (2) These records are passed into the RPC functions to be filled in.  The
     afs_decode_status() and yfs_decode_status() functions are removed and
     the cb_lock is no longer taken.

 (3) xdr_decode_AFSFetchStatus() and xdr_decode_YFSFetchStatus() no longer
     update the vnode.

 (4) xdr_decode_AFSCallBack() and xdr_decode_YFSCallBack() no longer update
     the vnode.

 (5) vnodes, expected data-version numbers and callback break counters
     (cb_break) no longer need to be passed to the reply delivery
     functions.

     Note that, for the moment, the file locking functions still need
     access to both the call and the vnode at the same time.

 (6) afs_vnode_commit_status() is now given the cb_break value and the
     expected data_version and the task of applying the status and the
     callback to the vnode are now done here.

     This is done under a single taking of vnode->cb_lock.

 (7) afs_pages_written_back() is now called by afs_store_data() rather than
     by the reply delivery function.

     afs_pages_written_back() has been moved to before the call point and
     is now given the first and last page numbers rather than a pointer to
     the call.

 (8) The indicator from YFS.RemoveFile2 as to whether the target file
     actually got removed (status.abort_code == VNOVNODE) rather than
     merely dropping a link is now checked in afs_unlink rather than in
     xdr_decode_YFSFetchStatus().

Supplementary fixes:

 (*) afs_cache_permit() now gets the caller_access mask from the
     afs_status_cb object rather than picking it out of the vnode's status
     record.  afs_fetch_status() returns caller_access through its argument
     list for this purpose also.

 (*) afs_inode_init_from_status() now uses a write lock on cb_lock rather
     than a read lock and now sets the callback inside the same critical
     section.

Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
4571577f16 afs: Always get the reply time
Always ask for the reply time from AF_RXRPC as it's used to calculate the
callback expiry time and lock expiry times, so it's needed by most FS
operations.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
87182759cd afs: Fix order-1 allocation in afs_do_lookup()
afs_do_lookup() will do an order-1 allocation to allocate status records if
there are more than 39 vnodes to stat.

Fix this by allocating an array of {status,callback} records for each vnode
we want to examine using vmalloc() if larger than a page.

This not only gets rid of the order-1 allocation, but makes it easier to
grow beyond 50 records for YFS servers.  It also allows us to move to
{status,callback} tuples for other calls too and makes it easier to lock
across the application of the status and the callback to the vnode.

Fixes: 5cf9dd55a0 ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
ffba718e93 afs: Get rid of afs_call::reply[]
Replace the afs_call::reply[] array with a bunch of typed members so that
the compiler can use type-checking on them.  It's also easier for the eye
to see what's going on.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
fefb2483dc afs: Don't pass the vnode pointer through into the inline bulk status op
Don't pass the vnode pointer through into the inline bulk status op.  We
want to process the status records outside of it anyway.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
fd711586bb afs: Fix double inc of vnode->cb_break
When __afs_break_callback() clears the CB_PROMISED flag, it increments
vnode->cb_break to trigger a future refetch of the status and callback -
however it also calls afs_clear_permits(), which also increments
vnode->cb_break.

Fix this by removing the increment from afs_clear_permits().

Whilst we're at it, fix the conditional call to afs_put_permits() as the
function checks to see if the argument is NULL, so the check is redundant.

Fixes: be080a6f43 ("afs: Overhaul permit caching");
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
c7226e407b afs: Fix lock-wait/callback-break double locking
__afs_break_callback() holds vnode->lock around its call of
afs_lock_may_be_available() - which also takes that lock.

Fix this by not taking the lock in __afs_break_callback().

Also, there's no point checking the granted_locks and pending_locks queues;
it's sufficient to check lock_state, so move that check out of
afs_lock_may_be_available() into __afs_break_callback() to replace the
queue checks.

Fixes: e8d6c55412 ("AFS: implement file locking")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
d9052dda8a afs: Don't invalidate callback if AFS_VNODE_DIR_VALID not set
Don't invalidate the callback promise on a directory if the
AFS_VNODE_DIR_VALID flag is not set (which indicates that the directory
contents are invalid, due to edit failure, callback break, page reclaim).

The directory will be reloaded next time the directory is accessed, so
clearing the callback flag at this point may race with a reload of the
directory and cancel it's recorded callback promise.

Fixes: f3ddee8dc4 ("afs: Fix directory handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
781070551c afs: Fix calculation of callback expiry time
Fix the calculation of the expiry time of a callback promise, as obtained
from operations like FS.FetchStatus and FS.FetchData.

The time should be based on the timestamp of the first DATA packet in the
reply and the calculation needs to turn the ktime_t timestamp into a
time64_t.

Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
3b05e528cb afs: Make dynamic root population wait uninterruptibly for proc_cells_lock
Make dynamic root population wait uninterruptibly for proc_cells_lock.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:21 +01:00
David Howells
20b8391fff afs: Make some RPC operations non-interruptible
Make certain RPC operations non-interruptible, including:

 (*) Set attributes
 (*) Store data

     We don't want to get interrupted during a flush on close, flush on
     unlock, writeback or an inode update, leaving us in a state where we
     still need to do the writeback or update.

 (*) Extend lock
 (*) Release lock

     We don't want to get lock extension interrupted as the file locks on
     the server are time-limited.  Interruption during lock release is less
     of an issue since the lock is time-limited, but it's better to
     complete the release to avoid a several-minute wait to recover it.

     *Setting* the lock isn't a problem if it's interrupted since we can
      just return to the user and tell them they were interrupted - at
      which point they can elect to retry.

 (*) Silly unlink

     We want to remove silly unlink files if we can, rather than leaving
     them for the salvager to clear up.

Note that whilst these calls are no longer interruptible, they do have
timeouts on them, so if the server stops responding the call will fail with
something like ETIME or ECONNRESET.

Without this, the following:

	kAFS: Unexpected error from FS.StoreData -512

appears in dmesg when a pending store data gets interrupted and some
processes may just hang.

Additionally, make the code that checks/updates the server record ignore
failure due to interruption if the main call is uninterruptible and if the
server has an address list.  The next op will check it again since the
expiration time on the old list has past.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:20 +01:00
David Howells
b960a34b73 rxrpc: Allow the kernel to mark a call as being non-interruptible
Allow kernel services using AF_RXRPC to indicate that a call should be
non-interruptible.  This allows kafs to make things like lock-extension and
writeback data storage calls non-interruptible.

If this is set, signals will be ignored for operations on that call where
possible - such as waiting to get a call channel on an rxrpc connection.

It doesn't prevent UDP sendmsg from being interrupted, but that will be
handled by packet retransmission.

rxrpc_kernel_recv_data() isn't affected by this since that never waits,
preferring instead to return -EAGAIN and leave the waiting to the caller.

Userspace initiated calls can't be set to be uninterruptible at this time.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:20 +01:00
David Howells
0ab4c95948 afs: Fix error propagation from server record check/update
afs_check/update_server_record() should be setting fc->error rather than
fc->ac.error as they're called from within the cursor iteration function.

afs_fs_cursor::error is where the error code of the attempt to call the
operation on multiple servers is integrated and is the final result,
whereas afs_addr_cursor::error is used to hold the error from individual
iterations of the call loop.  (Note there's also an afs_vl_cursor which
also wraps afs_addr_cursor for accessing VL servers rather than file
servers).

Fix this by setting fc->error in the afs_check/update_server_record() so
that any error incurred whilst talking to the VL server correctly
propagates to the final result.

This results in:

	kAFS: Unexpected error from FS.StoreData -512

being seen, even though the store-data op is non-interruptible.  The error
is actually coming from the server record update getting interrupted.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:20 +01:00
David Howells
94f699c9cd afs: Fix the maximum lifespan of VL and probe calls
If an older AFS server doesn't support an operation, it may accept the call
and then sit on it forever, happily responding to pings that make kafs
think that the call is still alive.

Fix this by setting the maximum lifespan of Volume Location service calls
in particular and probe calls in general so that they don't run on
endlessly if they're not supported.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 16:25:20 +01:00
David Howells
51eba99970 afs: Fix "kAFS: AFS vnode with undefined type 0"
Under some circumstances afs_select_fileserver() can return without setting
an error in fc->error.  The problem is in the no_more_servers segment where
the accumulated errors from attempts to contact various servers are
integrated into an afs_error-type variable 'e'.  The resultant error code
is, however, then abandoned.

Fix this by getting the error out of e.error and putting it in 'error' so
that the next part will store it into fc->error.

Not doing this causes a report like the following:

    kAFS: AFS vnode with undefined type 0
    kAFS: A=0 m=0 s=0 v=0
    kAFS: vnode 20000025:1:1

because the code following the server selection loop then sees what it
thinks is a successful invocation because fc.error is 0.  However, it can't
apply the status record because it's all zeros.

The report is followed on the first instance with a trace looking something
like:

     dump_stack+0x67/0x8e
     afs_inode_init_from_status.isra.2+0x21b/0x487
     afs_fetch_status+0x119/0x1df
     afs_iget+0x130/0x295
     afs_get_tree+0x31d/0x595
     vfs_get_tree+0x1f/0xe8
     fc_mount+0xe/0x36
     afs_d_automount+0x328/0x3c3
     follow_managed+0x109/0x20a
     lookup_fast+0x3bf/0x3f8
     do_last+0xc3/0x6a4
     path_openat+0x1af/0x236
     do_filp_open+0x51/0xae
     ? _raw_spin_unlock+0x24/0x2d
     ? __alloc_fd+0x1a5/0x1b7
     do_sys_open+0x13b/0x1e8
     do_syscall_64+0x7d/0x1b3
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 4584ae96ae ("afs: Fix missing net error handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 15:48:20 +01:00
David Howells
d5c32c89b2 afs: Fix cell DNS lookup
Currently, once configured, AFS cells are looked up in the DNS at regular
intervals - which is a waste of resources if those cells aren't being
used.  It also leads to a problem where cells preloaded, but not
configured, before the network is brought up end up effectively statically
configured with no VL servers and are unable to get any.

Fix this by not doing the DNS lookup until the first time a cell is
touched.  It is waited for if we don't have any cached records yet,
otherwise the DNS lookup to maintain the record is done in the background.

This has the downside that the first time you touch a cell, you now have to
wait for the upcall to do the required DNS lookups rather than them already
being cached.

Further, the record is not replaced if the old record has at least one
server in it and the new record doesn't have any.

Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-16 12:58:23 +01:00
David Howells
d0660f0b3b dns_resolver: Allow used keys to be invalidated
Allow used DNS resolver keys to be invalidated after use if the caller is
doing its own caching of the results.  This reduces the amount of resources
required.

Fix AFS to invalidate DNS results to kill off permanent failure records
that get lodged in the resolver keyring and prevent future lookups from
happening.

Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-15 17:35:54 +01:00
David Howells
ca1cbbdce9 afs: Fix afs_cell records to always have a VL server list record
Fix it such that afs_cell records always have a VL server list record
attached, even if it's a dummy one, so that various checks can be removed.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-15 17:35:53 +01:00
David Howells
6b8812fc8e afs: Fix missing lock when replacing VL server list
When afs_update_cell() replaces the cell->vl_servers list, it uses RCU
protocol so that proc is protected, but doesn't take ->vl_servers_lock to
protect afs_start_vl_iteration() (which does actually take a shared lock).

Fix this by making afs_update_cell() take an exclusive lock when replacing
->vl_servers.

Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-15 17:35:53 +01:00
David Howells
773e0c4025 afs: Fix afs_xattr_get_yfs() to not try freeing an error value
afs_xattr_get_yfs() tries to free yacl, which may hold an error value (say
if yfs_fs_fetch_opaque_acl() failed and returned an error).

Fix this by allocating yacl up front (since it's a fixed-length struct,
unlike afs_acl) and passing it in to the RPC function.  This also allows
the flags to be placed in the object rather than passing them through to
the RPC function.

Fixes: ae46578b96 ("afs: Get YFS ACLs and information through xattrs")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-15 17:35:53 +01:00
David Howells
cc1dd5c85c afs: Fix incorrect error handling in afs_xattr_get_acl()
Fix incorrect error handling in afs_xattr_get_acl() where there appears to
be a redundant assignment before return, but in fact the return should be a
goto to the error handling at the end of the function.

Fixes: 260f082bae ("afs: Get an AFS3 ACL as an xattr")
Addresses-Coverity: ("Unused Value")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Joe Perches <joe@perches.com>
2019-05-15 17:35:53 +01:00
David Howells
a1b879eefc afs: Fix key leak in afs_release() and afs_evict_inode()
Fix afs_release() to go through the cleanup part of the function if
FMODE_WRITE is set rather than exiting through vfs_fsync() (which skips the
cleanup).  The cleanup involves discarding the refs on the key used for
file ops and the writeback key record.

Also fix afs_evict_inode() to clean up any left over wb keys attached to
the inode/vnode when it is removed.

Fixes: 5a81327616 ("afs: Do better accretion of small writes on newly created content")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-15 12:32:34 +01:00
Linus Torvalds
e5fef2a973 AFS Development
-----BEGIN PGP SIGNATURE-----
 
 iQIVAwUAXNGpJPu3V2unywtrAQIVVQ//ZaEhskofcXYCsyO9pXshVKCZmp1pZ9Q3
 ecbTbrF18guwHfM25LURidtjBmEAeuG5NOac/XHxcUbn5NUVzBQ1FircTVmLgtGY
 yjrBmMSqIDYhghslLAv78/HibdHJ+Flqy3RWAMyDMecTvx7VGx4idZQl5QIDbNEb
 GNvGP3WRiHG8tm6dykfm3afQoAS+n5seBBPDFucqPzAYa/Z/mBLgaZRKbmuMwEAe
 Q2mAf7vhYgw55JzeTSZZ4sWGP9Z+9Mi/18Hu8QvJwsrJW+jHlzJHtJp0EphSa3Xs
 YIRx+6AQ7WqAhnBUzzY5nBzMClIfMv1GrCG/6rXTTI/UYX65kVAP5M8EW6BAI8oX
 Fz2hJqCIvF8ZCSxIYLqizlEkxmEvfmwYxueX9km/+dfTma+MIaajMge+n3fDYmls
 S4RONn2LuqVeIw3m8DtKUBr7VRP0J9s1z0O4kubCtZt5PKNekvzSQSMIc17sXSST
 Uuo7aL3W6Lxk4bLMmB8o/Rf2RHBZlhmpPk8rF+I6jd0Q45SDV/TttqygyvKZseDo
 MZbnmBiDElDWXyKE6gxQqdC13tpb3MlCPv1L+xKDPArXe9yjq2XvHY4NtYBMCa5U
 iO1v+6W1JrGh8bkE72YuxKcBVVOStQxhHGU4D8WKZjOI7oeU87U7AD/8kSRhKQni
 VRXY1z87sZk=
 =yiyv
 -----END PGP SIGNATURE-----

Merge tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS updates from David Howells:
 "A set of fix and development patches for AFS for 5.2.

  Summary:

   - Fix the AFS file locking so that sqlite can run on an AFS mount and
     also so that firefox and gnome can use a homedir that's mounted
     through AFS.

     This required emulation of fine-grained locking when the server
     will only support whole-file locks and no upgrade/downgrade. Four
     modes are provided, settable by mount parameter:

       "flock=local"   - No reference to the server

       "flock=openafs" - Fine-grained locks are local-only, whole-file
                         locks require sufficient server locks

       "flock=strict"  - All locks require sufficient server locks

       "flock=write"   - Always get an exclusive server lock

     If the volume is a read-only or backup volume, then flock=local for
     that volume.

   - Log extra information for a couple of cases where the client mucks
     up somehow: AFS vnode with undefined type and dir check failure -
     in both cases we seem to end up with unfilled data, but the issues
     happen infrequently and are difficult to reproduce at will.

   - Implement silly rename for unlink() and rename().

   - Set i_blocks so that du can get some information about usage.

   - Fix xattr handlers to return the right amount of data and to not
     overflow buffers.

   - Implement getting/setting raw AFS and YFS ACLs as xattrs"

* tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Implement YFS ACL setting
  afs: Get YFS ACLs and information through xattrs
  afs: implement acl setting
  afs: Get an AFS3 ACL as an xattr
  afs: Fix getting the afs.fid xattr
  afs: Fix the afs.cell and afs.volume xattr handlers
  afs: Calculate i_blocks based on file size
  afs: Log more information for "kAFS: AFS vnode with undefined type\n"
  afs: Provide mount-time configurable byte-range file locking emulation
  afs: Add more tracepoints
  afs: Implement sillyrename for unlink and rename
  afs: Add directory reload tracepoint
  afs: Handle lock rpc ops failing on a file that got deleted
  afs: Improve dir check failure reports
  afs: Add file locking tracepoints
  afs: Further fix file locking
  afs: Fix AFS file locking to allow fine grained locks
  afs: Calculate lock extend timer from set/extend reply reception
  afs: Split wait from afs_make_call()
2019-05-07 20:51:58 -07:00
Linus Torvalds
b4b52b881c Wimplicit-fallthrough patches for 5.2-rc1
Hi Linus,
 
 This is my very first pull-request.  I've been working full-time as
 a kernel developer for more than two years now. During this time I've
 been fixing bugs reported by Coverity all over the tree and, as part
 of my work, I'm also contributing to the KSPP. My work in the kernel
 community has been supervised by Greg KH and Kees Cook.
 
 OK. So, after the quick introduction above, please, pull the following
 patches that mark switch cases where we are expecting to fall through.
 These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
 They have been ignored for a long time (most of them more than 3 months,
 even after pinging multiple times), which is the reason why I've created
 this tree. Most of them have been baking in linux-next for a whole development
 cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
 going out for newly introduced code that triggers -Wimplicit-fallthrough
 to avoid gaining more of these cases while we work to remove the ones
 that are already present.
 
 I'm happy to let you know that we are getting close to completing this
 work.  Currently, there are only 32 of 2311 of these cases left to be
 addressed in linux-next.  I'm auditing every case; I take a look into
 the code and analyze it in order to determine if I'm dealing with an
 actual bug or a false positive, as explained here:
 
 https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
 
 While working on this, I've found and fixed the following missing
 break/return bugs, some of them introduced more than 5 years ago:
 
 84242b82d8
 7850b51b6c
 5e420fe635
 09186e5034
 b5be853181
 7264235ee7
 cc5034a5d2
 479826cc86
 5340f23df8
 df997abeeb
 2f10d82373
 307b00c5e6
 5d25ff7a54
 a7ed5b3e7d
 c24bfa8f21
 ad0eaee619
 9ba8376ce1
 dc586a60a1
 a8e9b186f1
 4e57562b48
 60747828ea
 c5b974bee9
 cc44ba9116
 2c930e3d0a
 
 Once this work is finish, we'll be able to universally enable
 "-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
 entering the kernel again.
 
 Thanks
 
 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEkmRahXBSurMIg1YvRwW0y0cG2zEFAlzQR2IACgkQRwW0y0cG
 2zEJbQ//X930OcBtT/9DRW4XL1Jeq0Mjssz/GLX2Vpup5CwwcTROG65no80Zezf/
 yQRWnUjGX0OBv/fmUK32/nTxI/7k7NkmIXJHe0HiEF069GEENB7FT6tfDzIPjU8M
 qQkB8NsSUWJs3IH6BVynb/9MGE1VpGBDbYk7CBZRtRJT1RMM+3kQPucgiZMgUBPo
 Yd9zKwn4i/8tcOCli++EUdQ29ukMoY2R3qpK4LftdX9sXLKZBWNwQbiCwSkjnvJK
 I6FDiA7RaWH2wWGlL7BpN5RrvAXp3z8QN/JZnivIGt4ijtAyxFUL/9KOEgQpBQN2
 6TBRhfTQFM73NCyzLgGLNzvd8awem1rKGSBBUvevaPbgesgM+Of65wmmTQRhFNCt
 A7+e286X1GiK3aNcjUKrByKWm7x590EWmDzmpmICxNPdt5DHQ6EkmvBdNjnxCMrO
 aGA24l78tBN09qN45LR7wtHYuuyR0Jt9bCmeQZmz7+x3ICDHi/+Gw7XPN/eM9+T6
 lZbbINiYUyZVxOqwzkYDCsdv9+kUvu3e4rPs20NERWRpV8FEvBIyMjXAg6NAMTue
 K+ikkyMBxCvyw+NMimHJwtD7ho4FkLPcoeXb2ZGJTRHixiZAEtF1RaQ7dA05Q/SL
 gbSc0DgLZeHlLBT+BSWC2Z8SDnoIhQFXW49OmuACwCUC68NHKps=
 =k30z
 -----END PGP SIGNATURE-----

Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
 "Mark switch cases where we are expecting to fall through.

  This is part of the ongoing efforts to enable -Wimplicit-fallthrough.

  Most of them have been baking in linux-next for a whole development
  cycle. And with Stephen Rothwell's help, we've had linux-next
  nag-emails going out for newly introduced code that triggers
  -Wimplicit-fallthrough to avoid gaining more of these cases while we
  work to remove the ones that are already present.

  We are getting close to completing this work. Currently, there are
  only 32 of 2311 of these cases left to be addressed in linux-next. I'm
  auditing every case; I take a look into the code and analyze it in
  order to determine if I'm dealing with an actual bug or a false
  positive, as explained here:

      https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/

  While working on this, I've found and fixed the several missing
  break/return bugs, some of them introduced more than 5 years ago.

  Once this work is finished, we'll be able to universally enable
  "-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
  entering the kernel again"

* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
  memstick: mark expected switch fall-throughs
  drm/nouveau/nvkm: mark expected switch fall-throughs
  NFC: st21nfca: Fix fall-through warnings
  NFC: pn533: mark expected switch fall-throughs
  block: Mark expected switch fall-throughs
  ASN.1: mark expected switch fall-through
  lib/cmdline.c: mark expected switch fall-throughs
  lib: zstd: Mark expected switch fall-throughs
  scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
  scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
  scsi: ppa: mark expected switch fall-through
  scsi: osst: mark expected switch fall-throughs
  scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
  scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
  scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
  scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
  scsi: imm: mark expected switch fall-throughs
  scsi: csiostor: csio_wr: mark expected switch fall-through
  ...
2019-05-07 12:48:10 -07:00
Linus Torvalds
168e153d5e Merge branch 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode freeing updates from Al Viro:
 "Introduction of separate method for RCU-delayed part of
  ->destroy_inode() (if any).

  Pretty much as posted, except that destroy_inode() stashes
  ->free_inode into the victim (anon-unioned with ->i_fops) before
  scheduling i_callback() and the last two patches (sockfs conversion
  and folding struct socket_wq into struct socket) are excluded - that
  pair should go through netdev once davem reopens his tree"

* 'work.icache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (58 commits)
  orangefs: make use of ->free_inode()
  shmem: make use of ->free_inode()
  hugetlb: make use of ->free_inode()
  overlayfs: make use of ->free_inode()
  jfs: switch to ->free_inode()
  fuse: switch to ->free_inode()
  ext4: make use of ->free_inode()
  ecryptfs: make use of ->free_inode()
  ceph: use ->free_inode()
  btrfs: use ->free_inode()
  afs: switch to use of ->free_inode()
  dax: make use of ->free_inode()
  ntfs: switch to ->free_inode()
  securityfs: switch to ->free_inode()
  apparmor: switch to ->free_inode()
  rpcpipe: switch to ->free_inode()
  bpf: switch to ->free_inode()
  mqueue: switch to ->free_inode()
  ufs: switch to ->free_inode()
  coda: switch to ->free_inode()
  ...
2019-05-07 10:57:05 -07:00
David Howells
f5e4546347 afs: Implement YFS ACL setting
Implement the setting of YFS ACLs in AFS through the interface of setting
the afs.yfs.acl extended attribute on the file.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
David Howells
ae46578b96 afs: Get YFS ACLs and information through xattrs
The YFS/AuriStor variant of AFS provides more capable ACLs and provides
per-volume ACLs and per-file ACLs as well as per-directory ACLs.  It also
provides some extra information that can be retrieved through four ACLs:

 (1) afs.yfs.acl

     The YFS file ACL (not the same format as afs.acl).

 (2) afs.yfs.vol_acl

     The YFS volume ACL.

 (3) afs.yfs.acl_inherited

     "1" if a file's ACL is inherited from its parent directory, "0"
     otherwise.

 (4) afs.yfs.acl_num_cleaned

     The number of of ACEs removed from the ACL by the server because the
     PT entries were removed from the PTS database (ie. the subject is no
     longer known).

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
Joe Gorse
b10494af49 afs: implement acl setting
Implements the setting of ACLs in AFS by means of setting the
afs.acl extended attribute on the file.

Signed-off-by: Joe Gorse <jhgorse@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
David Howells
260f082bae afs: Get an AFS3 ACL as an xattr
Implement an xattr on AFS files called "afs.acl" that retrieves a file's
ACL.  It returns the raw AFS3 ACL from the result of calling FS.FetchACL,
leaving any interpretation to userspace.

Note that whilst YFS servers will respond to FS.FetchACL, this will render
a more-advanced YFS ACL down.  Use "afs.yfs.acl" instead for that.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
David Howells
a2f611a3dc afs: Fix getting the afs.fid xattr
The AFS3 FID is three 32-bit unsigned numbers and is represented as three
up-to-8-hex-digit numbers separated by colons to the afs.fid xattr.
However, with the advent of support for YFS, the FID is now a 64-bit volume
number, a 96-bit vnode/inode number and a 32-bit uniquifier (as before).
Whilst the sprintf in afs_xattr_get_fid() has been partially updated (it
currently ignores the upper 32 bits of the 96-bit vnode number), the size
of the stack-based buffer has not been increased to match, thereby allowing
stack corruption to occur.

Fix this by increasing the buffer size appropriately and conditionally
including the upper part of the vnode number if it is non-zero.  The latter
requires the lower part to be zero-padded if the upper part is non-zero.

Fixes: 3b6492df41 ("afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
David Howells
c73aa4102f afs: Fix the afs.cell and afs.volume xattr handlers
Fix the ->get handlers for the afs.cell and afs.volume xattrs to pass the
source data size to memcpy() rather than target buffer size.

Overcopying the source data occasionally causes the kernel to oops.

Fixes: d3e3b7eac8 ("afs: Add metadata xattrs")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
Marc Dionne
c0abbb5791 afs: Calculate i_blocks based on file size
While it's not possible to give an accurate number for the blocks
used on the server, populate i_blocks based on the file size so
that 'du' can give a reasonable estimate.

The value is rounded up to 1K granularity, for consistency with
what other AFS clients report, and the servers' 1K usage quota
unit.  Note that the value calculated by 'du' at the root of a
volume can still be slightly lower than the quota usage on the
server, as 0-length files are charged 1 quota block, but are
reported as occupying 0 blocks.  Again, this is consistent with
other AFS clients.

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
David Howells
b134d687dd afs: Log more information for "kAFS: AFS vnode with undefined type\n"
Log more information when "kAFS: AFS vnode with undefined type\n" is
displayed due to a vnode record being retrieved from the server that
appears to have a duff file type (usually 0).  This prints more information
to try and help pin down the problem.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-07 16:48:44 +01:00
Al Viro
51b9fe48c4 afs: switch to use of ->free_inode()
debugging printks left in ->destroy_inode() and so's the
update of inode count; we could take the latter to RCU-delayed
part (would take only moving the check on module exit past
rcu_barrier() there), but debugging output ought to either
stay where it is or go into ->evict_inode()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-01 22:43:26 -04:00
David Howells
6c6c1d63c2 afs: Provide mount-time configurable byte-range file locking emulation
Provide byte-range file locking emulation that can be configured at mount
time to one of four modes:

 (1) flock=local.  Locking is done locally only and no reference is made to
     the server.

 (2) flock=openafs.  Byte-range locking is done locally only; whole-file
     locking is done with reference to the server.  Whole-file locks cannot
     be upgraded unless the client holds an exclusive lock.

 (3) flock=strict.  Byte-range and whole-file locking both require a
     sufficient whole-file lock on the server.

 (4) flock=write.  As strict, but the client always gets an exclusive
     whole-file lock on the server.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:52 +01:00
David Howells
80548b0399 afs: Add more tracepoints
Add four more tracepoints:

 (1) afs_make_fs_call1 - Split from afs_make_fs_call but takes a filename
     to log also.

 (2) afs_make_fs_call2 - Like the above but takes two filenames to log.

 (3) afs_lookup - Log the result of doing a successful lookup, including a
     negative result (fid 0:0).

 (4) afs_get_tree - Log the set up of a volume for mounting.

It also extends the name buffer on the afs_edit_dir tracepoint to 24 chars
and puts quotes around the filename in the text representation.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:51 +01:00
David Howells
79ddbfa500 afs: Implement sillyrename for unlink and rename
Implement sillyrename for AFS unlink and rename, using the NFS variant
implementation as a basis.

Note that the asynchronous file locking extender/releaser has to be
notified with a state change to stop it complaining if there's a race
between that and the actual file deletion.

A tracepoint, afs_silly_rename, is also added to note the silly rename and
the cleanup.  The afs_edit_dir tracepoint is given some extra reason
indicators and the afs_flock_ev tracepoint is given a silly-delete file
lock cancellation indicator.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:51 +01:00
David Howells
99987c5600 afs: Add directory reload tracepoint
Add a tracepoint (afs_reload_dir) to indicate when a directory is being
reloaded.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:51 +01:00
David Howells
cdfb26b40d afs: Handle lock rpc ops failing on a file that got deleted
Holding a file lock on an AFS file does not prevent it from being deleted
on the server, so we need to handle an error resulting from that when we
try setting, extending or releasing a lock.

Fix this by adding a "deleted" lock state and cancelling the lock extension
process for that file and aborting all waiters for the lock.

Fixes: 0fafdc9f88 ("afs: Fix file locking")
Reported-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:51 +01:00
David Howells
445b10289f afs: Improve dir check failure reports
Improve the content of directory check failure reports from:

	kAFS: afs_dir_check_page(6d57): bad magic 1/2 is 0000

to dump more information about the individual blocks in a directory page.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:51 +01:00
David Howells
d46966013b afs: Add file locking tracepoints
Add two tracepoints for monitoring AFS file locking.  Firstly, add one that
follows the operational part:

    echo 1 >/sys/kernel/debug/tracing/events/afs/afs_flock_op/enable

And add a second that more follows the event-driven part:

    echo 1 >/sys/kernel/debug/tracing/events/afs/afs_flock_ev/enable

Individual file_lock structs seen by afs are tagged with debugging IDs that
are displayed in the trace log to make it easier to see what's going on,
especially as setting the first lock always seems to involve copying the
file_lock twice.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:50 +01:00
David Howells
4be5975aea afs: Further fix file locking
Further fix the file locking in the afs filesystem client in a number of
ways, including:

 (1) Don't submit the operation to obtain a lock from the server in a work
     queue context, but rather do it in the process context of whoever
     issued the requesting system call.

 (2) The owner of the file_lock struct at the front of the pending_locks
     queue now owns right to talk to the server.

 (3) Write locks can be instantly granted if they don't overlap with any
     other locks *and* we have a write lock on the server.

 (4) In the event of an authentication/permission error, all other matching
     pending locks requests are also immediately aborted.

 (5) Properly use VFS core locks_lock_file_wait() to distribute the server
     lock amongst local client locks, including waiting for the lock to
     become available.

Test with:

	sqlite3 /afs/.../scratch/billings.sqlite <<EOF
	CREATE TABLE hosts (
	    hostname varchar(80),
	    shorthost varchar(80),
	    room varchar(30),
	    building varchar(30),
	    PRIMARY KEY(shorthost)
	    );
	EOF

With the version of sqlite3 that I have, this should fail consistently with
EAGAIN, whether or not the program is straced (which introduces some delays
between lock syscalls).

Fixes: 0fafdc9f88 ("afs: Fix file locking")
Reported-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:50 +01:00
David Howells
68ce801ffd afs: Fix AFS file locking to allow fine grained locks
Fix AFS file locking to allow fine grained locks as some applications, such
as firefox, won't work if they can't take such locks on certain state files
- thereby preventing the use of kAFS to distribute a home directory.

Note that this cannot be made completely functional as the protocol only
has provision for whole-file locks, so there exists the possibility of a
process deadlocking itself by getting a partial read-lock on a file first
and then trying to get a non-overlapping write-lock - but we got the
server's read lock with the first lock, so we're now stuck.

OpenAFS solves this by just granting any partial-range lock directly
without consulting the server - and hoping there's no remote collision.  I
want to implement that in a separate patch and it requires a bit more
thought.

Fixes: 8d6c554126b8 ("AFS: implement file locking")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:50 +01:00
David Howells
a690f60a2b afs: Calculate lock extend timer from set/extend reply reception
Record the timestamp on the first reply DATA packet received in response to
a set- or extend-lock operation, then use this to calculate the time
remaining till the lock expires rather than using whatever time the
requesting process wakes up and finishes processing the operation as a
base.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:50 +01:00
David Howells
0b9bf3812a afs: Split wait from afs_make_call()
Split the call to afs_wait_for_call_to_complete() from afs_make_call() to
make it easier to handle asynchronous calls and to make it easier to
convert a synchronous call to an asynchronous one in future, for instance
when someone tries to interrupt an operation by pressing Ctrl-C.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-25 14:26:50 +01:00
David Howells
eeba1e9cf3 afs: Fix in-progess ops to ignore server-level callback invalidation
The in-kernel afs filesystem client counts the number of server-level
callback invalidation events (CB.InitCallBackState* RPC operations) that it
receives from the server.  This is stored in cb_s_break in various
structures, including afs_server and afs_vnode.

If an inode is examined by afs_validate(), say, the afs_server copy is
compared, along with other break counters, to those in afs_vnode, and if
one or more of the counters do not match, it is considered that the
server's callback promise is broken.  At points where this happens,
AFS_VNODE_CB_PROMISED is cleared to indicate that the status must be
refetched from the server.

afs_validate() issues an FS.FetchStatus operation to get updated metadata -
and based on the updated data_version may invalidate the pagecache too.

However, the break counters are also used to determine whether to note a
new callback in the vnode (which would set the AFS_VNODE_CB_PROMISED flag)
and whether to cache the permit data included in the YFSFetchStatus record
by the server.


The problem comes when the server sends us a CB.InitCallBackState op.  The
first such instance doesn't cause cb_s_break to be incremented, but rather
causes AFS_SERVER_FL_NEW to be cleared - but thereafter, say some hours
after last use and all the volumes have been automatically unmounted and
the server has forgotten about the client[*], this *will* likely cause an
increment.

 [*] There are other circumstances too, such as the server restarting or
     needing to make space in its callback table.

Note that the server won't send us a CB.InitCallBackState op until we talk
to it again.

So what happens is:

 (1) A mount for a new volume is attempted, a inode is created for the root
     vnode and vnode->cb_s_break and AFS_VNODE_CB_PROMISED aren't set
     immediately, as we don't have a nominated server to talk to yet - and
     we may iterate through a few to find one.

 (2) Before the operation happens, afs_fetch_status(), say, notes in the
     cursor (fc.cb_break) the break counter sum from the vnode, volume and
     server counters, but the server->cb_s_break is currently 0.

 (3) We send FS.FetchStatus to the server.  The server sends us back
     CB.InitCallBackState.  We increment server->cb_s_break.

 (4) Our FS.FetchStatus completes.  The reply includes a callback record.

 (5) xdr_decode_AFSCallBack()/xdr_decode_YFSCallBack() check to see whether
     the callback promise was broken by checking the break counter sum from
     step (2) against the current sum.

     This fails because of step (3), so we don't set the callback record
     and, importantly, don't set AFS_VNODE_CB_PROMISED on the vnode.

This does not preclude the syscall from progressing, and we don't loop here
rechecking the status, but rather assume it's good enough for one round
only and will need to be rechecked next time.

 (6) afs_validate() it triggered on the vnode, probably called from
     d_revalidate() checking the parent directory.

 (7) afs_validate() notes that AFS_VNODE_CB_PROMISED isn't set, so doesn't
     update vnode->cb_s_break and assumes the vnode to be invalid.

 (8) afs_validate() needs to calls afs_fetch_status().  Go back to step (2)
     and repeat, every time the vnode is validated.

This primarily affects volume root dir vnodes.  Everything subsequent to
those inherit an already incremented cb_s_break upon mounting.


The issue is that we assume that the callback record and the cached permit
information in a reply from the server can't be trusted after getting a
server break - but this is wrong since the server makes sure things are
done in the right order, holding up our ops if necessary[*].

 [*] There is an extremely unlikely scenario where a reply from before the
     CB.InitCallBackState could get its delivery deferred till after - at
     which point we think we have a promise when we don't.  This, however,
     requires unlucky mass packet loss to one call.

AFS_SERVER_FL_NEW tries to paper over the cracks for the initial mount from
a server we've never contacted before, but this should be unnecessary.
It's also further insulated from the problem on an initial mount by
querying the server first with FS.GetCapabilities, which triggers the
CB.InitCallBackState.


Fix this by

 (1) Remove AFS_SERVER_FL_NEW.

 (2) In afs_calc_vnode_cb_break(), don't include cb_s_break in the
     calculation.

 (3) In afs_cb_is_broken(), don't include cb_s_break in the check.


Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13 08:37:37 +01:00
Marc Dionne
21bd68f196 afs: Unlock pages for __pagevec_release()
__pagevec_release() complains loudly if any page in the vector is still
locked.  The pages need to be locked for generic_error_remove_page(), but
that function doesn't actually unlock them.

Unlock the pages afterwards.

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
2019-04-13 08:37:37 +01:00
David Howells
8022c4b95c afs: Differentiate abort due to unmarshalling from other errors
Differentiate an abort due to an unmarshalling error from an abort due to
other errors, such as ENETUNREACH.  It doesn't make sense to set abort code
RXGEN_*_UNMARSHAL in such a case, so use RX_USER_ABORT instead.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13 08:37:37 +01:00
Andi Kleen
d2abfa86ff afs: Avoid section confusion in CM_NAME
__tracepoint_str cannot be const because the tracepoint_str
section is not read-only. Remove the stray const.

Cc: dhowells@redhat.com
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2019-04-13 08:37:36 +01:00
Arnd Bergmann
ba25b81e3a afs: avoid deprecated get_seconds()
get_seconds() has a limited range on 32-bit architectures and is
deprecated because of that. While AFS uses the same limits for
its inode timestamps on the wire protocol, let's just use the
simpler current_time() as we do for other file systems.

This will still zero out the 'tv_nsec' field of the timestamps
internally.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-04-13 08:37:36 +01:00
Marc Dionne
f7f1dd3162 afs: Check for rxrpc call completion in wait loop
Check the state of the rxrpc call backing an afs call in each iteration of
the call wait loop in case the rxrpc call has already been terminated at
the rxrpc layer.

Interrupt the wait loop and mark the afs call as complete if the rxrpc
layer call is complete.

There were cases where rxrpc errors were not passed up to afs, which could
result in this loop waiting forever for an afs call to transition to
AFS_CALL_COMPLETE while the rx call was already complete.

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 16:57:23 -07:00
Marc Dionne
4611da30d6 rxrpc: Make rxrpc_kernel_check_life() indicate if call completed
Make rxrpc_kernel_check_life() pass back the life counter through the
argument list and return true if the call has not yet completed.

Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 16:57:23 -07:00
Gustavo A. R. Silva
e690c9e3f4 afs: Mark expected switch fall-throughs
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.

In other cases I had to tweak a bit the format of the comments.

This patch suppresses ALL missing-break-in-switch false positives
in fs/afs

Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2019-04-08 18:35:56 -05:00
David Howells
8c7ae38d1c afs: Fix StoreData op marshalling
The marshalling of AFS.StoreData, AFS.StoreData64 and YFS.StoreData64 calls
generated by ->setattr() ops for the purpose of expanding a file is
incorrect due to older documentation incorrectly describing the way the RPC
'FileLength' parameter is meant to work.

The older documentation says that this is the length the file is meant to
end up at the end of the operation; however, it was never implemented this
way in any of the servers, but rather the file is truncated down to this
before the write operation is effected, and never expanded to it (and,
indeed, it was renamed to 'TruncPos' in 2014).

Fix this by setting the position parameter to the new file length and doing
a zero-lengh write there.

The bug causes Xwayland to SIGBUS due to unexpected non-expansion of a file
it then mmaps.  This can be tested by giving the following test program a
filename in an AFS directory:

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <sys/mman.h>
	int main(int argc, char *argv[])
	{
		char *p;
		int fd;
		if (argc != 2) {
			fprintf(stderr,
				"Format: test-trunc-mmap <file>\n");
			exit(2);
		}
		fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC);
		if (fd < 0) {
			perror(argv[1]);
			exit(1);
		}
		if (ftruncate(fd, 0x140008) == -1) {
			perror("ftruncate");
			exit(1);
		}
		p = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
			 MAP_SHARED, fd, 0);
		if (p == MAP_FAILED) {
			perror("mmap");
			exit(1);
		}
		p[0] = 'a';
		if (munmap(p, 4096) < 0) {
			perror("munmap");
			exit(1);
		}
		if (close(fd) < 0) {
			perror("close");
			exit(1);
		}
		exit(0);
	}

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Reported-by: Jonathan Billings <jsbillin@umich.edu>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-28 08:54:20 -07:00
Linus Torvalds
7b47a9e7c8 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount infrastructure updates from Al Viro:
 "The rest of core infrastructure; no new syscalls in that pile, but the
  old parts are switched to new infrastructure. At that point
  conversions of individual filesystems can happen independently; some
  are done here (afs, cgroup, procfs, etc.), there's also a large series
  outside of that pile dealing with NFS (quite a bit of option-parsing
  stuff is getting used there - it's one of the most convoluted
  filesystems in terms of mount-related logics), but NFS bits are the
  next cycle fodder.

  It got seriously simplified since the last cycle; documentation is
  probably the weakest bit at the moment - I considered dropping the
  commit introducing Documentation/filesystems/mount_api.txt (cutting
  the size increase by quarter ;-), but decided that it would be better
  to fix it up after -rc1 instead.

  That pile allows to do followup work in independent branches, which
  should make life much easier for the next cycle. fs/super.c size
  increase is unpleasant; there's a followup series that allows to
  shrink it considerably, but I decided to leave that until the next
  cycle"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  afs: Use fs_context to pass parameters over automount
  afs: Add fs_context support
  vfs: Add some logging to the core users of the fs_context log
  vfs: Implement logging through fs_context
  vfs: Provide documentation for new mount API
  vfs: Remove kern_mount_data()
  hugetlbfs: Convert to fs_context
  cpuset: Use fs_context
  kernfs, sysfs, cgroup, intel_rdt: Support fs_context
  cgroup: store a reference to cgroup_ns into cgroup_fs_context
  cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
  cgroup_do_mount(): massage calling conventions
  cgroup: stash cgroup_root reference into cgroup_fs_context
  cgroup2: switch to option-by-option parsing
  cgroup1: switch to option-by-option parsing
  cgroup: take options parsing into ->parse_monolithic()
  cgroup: fold cgroup1_mount() into cgroup1_get_tree()
  cgroup: start switching to fs_context
  ipc: Convert mqueue fs to fs_context
  proc: Add fs_context support to procfs
  ...
2019-03-12 14:08:19 -07:00
Nikolay Borisov
b5420237ec mm: refactor readahead defines in mm.h
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD

[akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 10:04:01 -07:00
David Howells
c99c2171fc afs: Use fs_context to pass parameters over automount
Alter the AFS automounting code to create and modify an fs_context struct
when parameterising a new mount triggered by an AFS mountpoint rather than
constructing device name and option strings.

Also remove the cell=, vol= and rwpath options as they are then redundant.
The reason they existed is because the 'device name' may be derived
literally from a mountpoint object in the filesystem, so default cell and
parent-type information needed to be passed in by some other method from
the automount routines.  The vol= option didn't end up being used.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric W. Biederman <ebiederm@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:39 -05:00
David Howells
13fcc68370 afs: Add fs_context support
Add fs_context support to the AFS filesystem, converting the parameter
parsing to store options there.

This will form the basis for namespace propagation over mountpoints within
the AFS model, thereby allowing AFS to be used in containers more easily.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:38 -05:00
David Howells
7d762d6914 afs: Fix manually set volume location server list
When a cell with a volume location server list is added manually by
echoing the details into /proc/net/afs/cells, a record is added but the
flag saying it has been looked up isn't set.

This causes the VL server rotation code to wait forever, with the top of
/proc/pid/stack looking like:

	afs_select_vlserver+0x3a6/0x6f3
	afs_vl_lookup_vldb+0x4b/0x92
	afs_create_volume+0x25/0x1b9
	...

with the thread stuck in afs_start_vl_iteration() waiting for
AFS_CELL_FL_NO_LOOKUP_YET to be cleared.

Fix this by clearing AFS_CELL_FL_NO_LOOKUP_YET when setting up a record
if that record's details were supplied manually.

Fixes: 0a5143f2f8 ("afs: Implement VL server rotation")
Reported-by: Dave Botsch <dwb7@cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-25 11:59:07 -08:00
David Howells
34fa47612b afs: Fix race in async call refcounting
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.

afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.

Fix this by:

 (1) Getting an extra ref for an asynchronous call for the call itself to
     hold.  This makes sure the call doesn't evaporate on us accidentally
     and will allow the call to be retained by the caller in a future
     patch.  The ref is released on leaving afs_make_call() or
     afs_wait_for_call_to_complete().

 (2) In the event of an error from rxrpc_kernel_send_data():

     (a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
     	 call has been aborted and ended.  This prevents
     	 afs_deliver_to_call() from doing anything with any notifications
     	 it gets.

     (b) Explicitly end the call immediately to prevent further callbacks.

     (c) Cancel any queued async_work and wait for the work if it's
     	 executing.  This allows us to be sure the race won't recur when we
     	 change the state.  We put the work queue's ref on the call if we
     	 managed to cancel it.

     (d) Put the call's ref that we got in (1).  This belongs to us as long
     	 as the call is in state AFS_CALL_CL_REQUESTING.

Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:17:28 +00:00
David Howells
7a75b0079a afs: Provide a function to get a ref on a call
Provide a function to get a reference on an afs_call struct.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:17:28 +00:00
David Howells
59d49076ae afs: Fix key refcounting in file locking code
Fix the refcounting of the authentication keys in the file locking code.
The vnode->lock_key member points to a key on which it expects to be
holding a ref, but it isn't always given an extra ref, however.

Fixes: 0fafdc9f88 ("afs: Fix file locking")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:17:28 +00:00
Marc Dionne
4882a27cec afs: Don't set vnode->cb_s_break in afs_validate()
A cb_interest record is not necessarily attached to the vnode on entry to
afs_validate(), which can cause an oops when we try to bring the vnode's
cb_s_break up to date in the default case (ie. no current callback promise
and the vnode has not been deleted).

Fix this by simply removing the line, as vnode->cb_s_break will be set when
needed by afs_register_server_cb_interest() when we next get a callback
promise from RPC call.

The oops looks something like:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
    ...
    RIP: 0010:afs_validate+0x66/0x250 [kafs]
    ...
    Call Trace:
     afs_d_revalidate+0x8d/0x340 [kafs]
     ? __d_lookup+0x61/0x150
     lookup_dcache+0x44/0x70
     ? lookup_dcache+0x44/0x70
     __lookup_hash+0x24/0xa0
     do_unlinkat+0x11d/0x2c0
     __x64_sys_unlink+0x23/0x30
     do_syscall_64+0x4d/0xf0
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: ae3b7361dc ("afs: Fix validation/callback interaction")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:15:52 +00:00
Marc Dionne
5edc22cc1d afs: Set correct lock type for the yfs CreateFile
A lock type of 0 is "LockRead", which makes the fileserver record an
unintentional read lock on the new file.  This will cause problems
later on if the file is the subject of locking operations.

The correct default value should be -1 ("LockNone").

Fix the operation marshalling code to set the value and provide an enum to
symbolise the values whilst we're at it.

Fixes: 30062bd13e ("afs: Implement YFS support in the fs client")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-10 17:12:05 +00:00
Gustavo A. R. Silva
c2b8bd49d3 afs: Use struct_size() in kzalloc()
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 = kzalloc(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 = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-10 17:12:05 +00:00
Nikolay Borisov
f86196ea87 fs: don't open code lru_to_page()
Multiple filesystems open code lru_to_page().  Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.

No functional changes.

Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com>		[ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:48 -08:00
Davidlohr Bueso
08d405c8b8 fs/: remove caller signal_pending branch predictions
This is already done for us internally by the signal machinery.

[akpm@linux-foundation.org: fix fs/buffer.c]
Link: http://lkml.kernel.org/r/20181116002713.8474-7-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:48 -08:00
Linus Torvalds
5f1ca5c619 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Assorted fixes all over the place.

  The iov_iter one is this cycle regression (splice from UDP triggering
  WARN_ON()), the rest is older"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs: Use d_instantiate() rather than d_add() and don't d_drop()
  afs: Fix missing net error handling
  afs: Fix validation/callback interaction
  iov_iter: teach csum_and_copy_to_iter() to handle pipe-backed ones
  exportfs: do not read dentry after free
  exportfs: fix 'passing zero to ERR_PTR()' warning
  aio: fix failure to put the file pointer
  sysv: return 'err' instead of 0 in __sysv_write_inode
2018-11-30 10:47:50 -08:00
David Howells
73116df7bb afs: Use d_instantiate() rather than d_add() and don't d_drop()
Use d_instantiate() rather than d_add() and don't d_drop() in
afs_vnode_new_inode().  The dentry shouldn't be removed as it's not
changing its name.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-11-29 21:08:14 -05:00
David Howells
4584ae96ae afs: Fix missing net error handling
kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.

Fix this by:

 (1) Abstracting out the error prioritisation from the VL and FS rotation
     algorithms into a common function and expand usage into the server
     probing code.

     When multiple errors are available, this code selects the one we'd
     prefer to return.

 (2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.

Fixes: 0fafdc9f88 ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-11-29 21:08:14 -05:00
David Howells
ae3b7361dc afs: Fix validation/callback interaction
When afs_validate() is called to validate a vnode (inode), there are two
unhandled cases in the fastpath at the top of the function:

 (1) If the vnode is promised (AFS_VNODE_CB_PROMISED is set), the break
     counters match and the data has expired, then there's an implicit case
     in which the vnode needs revalidating.

     This has no consequences since the default "valid = false" set at the
     top of the function happens to do the right thing.

 (2) If the vnode is not promised and it hasn't been deleted
     (AFS_VNODE_DELETED is not set) then there's a default case we're not
     handling in which the vnode is invalid.  If the vnode is invalid, we
     need to bring cb_s_break and cb_v_break up to date before we refetch
     the status.

     As a consequence, once the server loses track of the client
     (ie. sufficient time has passed since we last sent it an operation),
     it will send us a CB.InitCallBackState* operation when we next try to
     talk to it.  This calls afs_init_callback_state() which increments
     afs_server::cb_s_break, but this then doesn't propagate to the
     afs_vnode record.

     The result being that every afs_validate() call thereafter sends a
     status fetch operation to the server.

Clarify and fix this by:

 (A) Setting valid in all the branches rather than initialising it at the
     top so that the compiler catches where we've missed.

 (B) Restructuring the logic in the 'promised' branch so that we set valid
     to false if the callback is due to expire (or has expired) and so that
     the final case is that the vnode is still valid.

 (C) Adding an else-statement that ups cb_s_break and cb_v_break if the
     promised and deleted cases don't match.

Fixes: c435ee3455 ("afs: Overhaul the callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-11-29 21:08:14 -05:00
David Howells
7150ceaacb rxrpc: Fix life check
The life-checking function, which is used by kAFS to make sure that a call
is still live in the event of a pending signal, only samples the received
packet serial number counter; it doesn't actually provoke a change in the
counter, rather relying on the server to happen to give us a packet in the
time window.

Fix this by adding a function to force a ping to be transmitted.

kAFS then keeps track of whether there's been a stall, and if so, uses the
new function to ping the server, resetting the timeout to allow the reply
to come back.

If there's a stall, a ping and the call is *still* stalled in the same
place after another period, then the call will be aborted.

Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Fixes: f4d15fb6f9 ("rxrpc: Provide functions for allowing cleaner handling of signals")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-15 11:35:40 -08:00
David Howells
3bf0fb6f33 afs: Probe multiple fileservers simultaneously
Send probes to all the unprobed fileservers in a fileserver list on all
addresses simultaneously in an attempt to find out the fastest route whilst
not getting stuck for 20s on any server or address that we don't get a
reply from.

This alleviates the problem whereby attempting to access a new server can
take a long time because the rotation algorithm ends up rotating through
all servers and addresses until it finds one that responds.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:09 +01:00
David Howells
18ac61853c afs: Fix callback handling
In some circumstances, the callback interest pointer is NULL, so in such a
case we can't dereference it when checking to see if the callback is
broken.  This causes an oops in some circumstances.

Fix this by replacing the function that worked out the aggregate break
counter with one that actually does the comparison, and then make that
return true (ie. broken) if there is no callback interest as yet (ie. the
pointer is NULL).

Fixes: 68251f0a68 ("afs: Fix whole-volume callback handling")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:09 +01:00
David Howells
2feeaf8433 afs: Eliminate the address pointer from the address list cursor
Eliminate the address pointer from the address list cursor as it's
redundant (ac->addrs[ac->index] can be used to find the same address) and
address lists must be replaced rather than being rearranged, so is of
limited value.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:09 +01:00
David Howells
744bcd713a afs: Allow dumping of server cursor on operation failure
Provide an option to allow the file or volume location server cursor to be
dumped if the rotation routine falls off the end without managing to
contact a server.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:09 +01:00
David Howells
30062bd13e afs: Implement YFS support in the fs client
Implement support for talking to YFS-variant fileservers in the cache
manager and the filesystem client.  These implement upgraded services on
the same port as their AFS services.

YFS fileservers provide expanded capabilities over AFS.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
d4936803a9 afs: Expand data structure fields to support YFS
Expand fields in various data structures to support the expanded
information that YFS is capable of returning.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
f58db83fd3 afs: Get the target vnode in afs_rmdir() and get a callback on it
Get the target vnode in afs_rmdir() and validate it before we attempt the
deletion, The vnode pointer will be passed through to the delivery function
in a later patch so that the delivery function can mark it deleted.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
12d8e95a91 afs: Calc callback expiry in op reply delivery
Calculate the callback expiration time at the point of operation reply
delivery, using the reply time queried from AF_RXRPC on that call as a
base.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
36bb5f490a afs: Fix FS.FetchStatus delivery from updating wrong vnode
The FS.FetchStatus reply delivery function was updating inode of the
directory in which a lookup had been done with the status of the looked up
file.  This corrupts some of the directory state.

Fixes: 5cf9dd55a0 ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
35dbfba311 afs: Implement the YFS cache manager service
Implement the YFS cache manager service which gives extra capabilities on
top of AFS.  This is done by listening for an additional service on the
same port and indicating that anyone requesting an upgrade should be
upgraded to the YFS port.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
06aeb29714 afs: Remove callback details from afs_callback_break struct
Remove unnecessary details of a broken callback, such as version, expiry
and type, from the afs_callback_break struct as they're not actually used
and make the list take more memory.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
0067191201 afs: Commit the status on a new file/dir/symlink
Call the function to commit the status on a new file, dir or symlink so
that the access rights for the caller's key are cached for that object.

Without this, the next access to the file will cause a FetchStatus
operation to be emitted to retrieve the access rights.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
3b6492df41 afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
Increase the sizes of the volume ID to 64 bits and the vnode ID (inode
number equivalent) to 96 bits to allow the support of YFS.

This requires the iget comparator to check the vnode->fid rather than i_ino
and i_generation as i_ino is not sufficiently capacious.  It also requires
this data to be placed into the vnode cache key for fscache.

For the moment, just discard the top 32 bits of the vnode ID when returning
it though stat.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
2a0b4f64c9 afs: Don't invoke the server to read data beyond EOF
When writing a new page, clear space in the page rather than attempting to
load it from the server if the space is beyond the EOF.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:08 +01:00
David Howells
f51375cd9e afs: Add a couple of tracepoints to log I/O errors
Add a couple of tracepoints to log the production of I/O errors within the AFS
filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
4ac15ea536 afs: Handle EIO from delivery function
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: 98bf40cd99 ("afs: Protect call->state changes against signals")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
ded2f4c58a afs: Fix TTL on VL server and address lists
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: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
0a5143f2f8 afs: Implement VL server rotation
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: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
e7f680f45b afs: Improve FS server rotation error handling
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: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
12bdcf333f afs: Set up the iov_iter before calling afs_extract_data()
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: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
160cb9574b afs: Better tracing of protocol errors
Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells
aa563d7bca iov_iter: Separate type from direction and use accessor functions
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: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David S. Miller
2e2d6f0342 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
net/sched/cls_api.c has overlapping changes to a call to
nlmsg_parse(), one (from 'net') added rtm_tca_policy instead of NULL
to the 5th argument, and another (from 'net-next') added cb->extack
instead of NULL to the 6th argument.

net/ipv4/ipmr_base.c is a case of a bug fix in 'net' being done to
code which moved (to mr_table_dump)) in 'net-next'.  Thanks to David
Ahern for the heads up.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-19 11:03:06 -07:00
David Howells
f0a7d1883d afs: Fix clearance of reply
The recent patch to fix the afs_server struct leak didn't actually fix the
bug, but rather fixed some of the symptoms.  The problem is that an
asynchronous call that holds a resource pointed to by call->reply[0] will
find the pointer cleared in the call destructor, thereby preventing the
resource from being cleaned up.

In the case of the server record leak, the afs_fs_get_capabilities()
function in devel code sets up a call with reply[0] pointing at the server
record that should be altered when the result is obtained, but this was
being cleared before the destructor was called, so the put in the
destructor does nothing and the record is leaked.

Commit f014ffb025 removed the additional ref obtained by
afs_install_server(), but the removal of this ref is actually used by the
garbage collector to mark a server record as being defunct after the record
has expired through lack of use.

The offending clearance of call->reply[0] upon completion in
afs_process_async_call() has been there from the origin of the code, but
none of the asynchronous calls actually use that pointer currently, so it
should be safe to remove (note that synchronous calls don't involve this
function).

Fix this by the following means:

 (1) Revert commit f014ffb025.

 (2) Remove the clearance of reply[0] from afs_process_async_call().

Without this, afs_manage_servers() will suffer an assertion failure if it
sees a server record that didn't get used because the usage count is not 1.

Fixes: f014ffb025 ("afs: Fix afs_server struct leak")
Fixes: 08e0e7c82e ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.")
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-15 15:31:47 +02:00
David S. Miller
d864991b22 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-12 21:38:46 -07:00
David Howells
f014ffb025 afs: Fix afs_server struct leak
Fix a leak of afs_server structs.  The routine that installs them in the
various lookup lists and trees gets a ref on leaving the function, whether
it added the server or a server already exists.  It shouldn't increment
the refcount if it added the server.

The effect of this that "rmmod kafs" will hang waiting for the leaked
server to become unused.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-12 17:36:40 +02:00
David Howells
6b3944e42e afs: Fix cell proc list
Access to the list of cells by /proc/net/afs/cells has a couple of
problems:

 (1) It should be checking against SEQ_START_TOKEN for the keying the
     header line.

 (2) It's only holding the RCU read lock, so it can't just walk over the
     list without following the proper RCU methods.

Fix these by using an hlist instead of an ordinary list and using the
appropriate accessor functions to follow it with RCU.

Since the code that adds a cell to the list must also necessarily change,
sort the list on insertion whilst we're at it.

Fixes: 989782dcdc ("afs: Overhaul cell database management")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-12 13:18:57 +02:00
David Howells
46894a1359 rxrpc: Use IPv4 addresses throught the IPv6
AF_RXRPC opens an IPv6 socket through which to send and receive network
packets, both IPv6 and IPv4.  It currently turns AF_INET addresses into
AF_INET-as-AF_INET6 addresses based on an assumption that this was
necessary; on further inspection of the code, however, it turns out that
the IPv6 code just farms packets aimed at AF_INET addresses out to the IPv4
code.

Fix AF_RXRPC to use AF_INET addresses directly when given them.

Fixes: 7b674e390e ("rxrpc: Fix IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-04 09:32:28 +01:00