Commit Graph

65311 Commits

Author SHA1 Message Date
Luis Henriques
878dabb641 ceph: don't return -ESTALE if there's still an open file
Similarly to commit 03f219041f ("ceph: check i_nlink while converting
a file handle to dentry"), this fixes another corner case with
name_to_handle_at/open_by_handle_at.  The issue has been detected by
xfstest generic/467, when doing:

 - name_to_handle_at("/cephfs/myfile")
 - open("/cephfs/myfile")
 - unlink("/cephfs/myfile")
 - sync; sync;
 - drop caches
 - open_by_handle_at()

The call to open_by_handle_at should not fail because the file hasn't been
deleted yet (only unlinked) and we do have a valid handle to it.  -ESTALE
shall be returned only if i_nlink is 0 *and* i_count is 1.

This patch also makes sure we have LINK caps before checking i_nlink.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:53 +02:00
Luis Henriques
dffdcd7145 ceph: allow rename operation under different quota realms
Returning -EXDEV when trying to 'mv' files/directories from different
quota realms results in copy+unlink operations instead of the faster
CEPH_MDS_OP_RENAME.  This will occur even when there aren't any quotas
set in the destination directory, or if there's enough space left for
the new file(s).

This patch adds a new helper function to be called on rename operations
which will allow these operations if they can be executed.  This patch
mimics userland fuse client commit b8954e5734b3 ("client:
optimize rename operation under different quota root").

Since ceph_quota_is_same_realm() is now called only from this new
helper, make it static.

URL: https://tracker.ceph.com/issues/44791
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:53 +02:00
Luis Henriques
daa668fbac ceph: normalize 'delta' parameter usage in check_quota_exceeded
Function check_quota_exceeded() uses delta parameter only for the
QUOTA_CHECK_MAX_BYTES_OP operation.  Using this parameter also for
MAX_FILES will makes the code cleaner and will be required to support
cross-quota-tree renames.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:53 +02:00
Jeff Layton
829ad4db95 ceph: ceph_kick_flushing_caps needs the s_mutex
The mdsc->cap_dirty_lock is not held while walking the list in
ceph_kick_flushing_caps, which is not safe.

ceph_early_kick_flushing_caps does something similar, but the
s_mutex is held while it's called and I think that guards against
changes to the list.

Ensure we hold the s_mutex when calling ceph_kick_flushing_caps,
and add some clarifying comments.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:53 +02:00
Jeff Layton
d67c72e6cc ceph: request expedited service on session's last cap flush
When flushing a lot of caps to the MDS's at once (e.g. for syncfs),
we can end up waiting a substantial amount of time for MDS replies, due
to the fact that it may delay some of them so that it can batch them up
together in a single journal transaction. This can lead to stalls when
calling sync or syncfs.

What we'd really like to do is request expedited service on the _last_
cap we're flushing back to the server. If the CHECK_CAPS_FLUSH flag is
set on the request and the current inode was the last one on the
session->s_cap_dirty list, then mark the request with
CEPH_CLIENT_CAPS_SYNC.

Note that this heuristic is not perfect. New inodes can race onto the
list after we've started flushing, but it does seem to fix some common
use cases.

URL: https://tracker.ceph.com/issues/44744
Reported-by: Jan Fajerski <jfajerski@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
1cf03a68e7 ceph: convert mdsc->cap_dirty to a per-session list
This is a per-sb list now, but that makes it difficult to tell when
the cap is the last dirty one associated with the session. Switch
this to be a per-session list, but continue using the
mdsc->cap_dirty_lock to protect the lists.

This list is only ever walked in ceph_flush_dirty_caps, so change that
to walk the sessions array and then flush the caps for inodes on each
session's list.

If the auth cap ever changes while the inode has dirty caps, then
move the inode to the appropriate session for the new auth_cap. Also,
ensure that we never remove an auth cap while the inode is still on the
s_cap_dirty list.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Yan, Zheng
6f05b30ea0 ceph: reset i_requested_max_size if file write is not wanted
write can stuck at waiting for larger max_size in following sequence of
events:

- client opens a file and writes to position 'A' (larger than unit of
  max size increment)
- client closes the file handle and updates wanted caps (not wanting
  file write caps)
- client opens and truncates the file, writes to position 'A' again.

At the 1st event, client set inode's requested_max_size to 'A'. At the
2nd event, mds removes client's writable range, but client does not reset
requested_max_size. At the 3rd event, client does not request max size
because requested_max_size is already larger than 'A'.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
88828190f0 ceph: throw a warning if we destroy session with mutex still locked
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
dc3da0461c ceph: fix potential race in ceph_check_caps
Nothing ensures that session will still be valid by the time we
dereference the pointer. Take and put a reference.

In principle, we should always be able to get a reference here, but
throw a warning if that's ever not the case.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
4fb5dda39c ceph: document what protects i_dirty_item and i_flushing_item
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
7833323363 ceph: don't take i_ceph_lock in handle_cap_import
Just take it before calling it. This means we have to do a couple of
minor in-memory operations under the spinlock now, but those shouldn't
be an issue.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
7391fba267 ceph: don't release i_ceph_lock in handle_cap_trunc
There's no reason to do this here. Just have the caller handle it.
Also, add a lockdep assertion.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
d7dbfb4f2b ceph: add comments for handle_cap_flush_ack logic
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
681ac63488 ceph: split up __finish_cap_flush
This function takes a mdsc argument or ci argument, but if both are
passed in, it ignores the ci arg. Fortunately, nothing does that, but
there's no good reason to have the same function handle both cases.

Also, get rid of some branches and just use |= to set the wake_* vals.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:52 +02:00
Jeff Layton
0a454bdd50 ceph: reorganize __send_cap for less spinlock abuse
Get rid of the __releases annotation by breaking it up into two
functions: __prep_cap which is done under the spinlock and __send_cap
that is done outside it. Add new fields to cap_msg_args for the wake
boolean and old_xattr_buf pointer.

Nothing checks the return value from __send_cap, so make it void
return.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:51 +02:00
Xiubo Li
70c948206f ceph: add metadata perf metric support
Add a new "r_ended" field to struct ceph_mds_request and use that to
maintain the average latency of MDS requests.

URL: https://tracker.ceph.com/issues/43215
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:51 +02:00
Xiubo Li
97e27aaa9a ceph: add read/write latency metric support
Calculate the latency for OSD read requests. Add a new r_end_stamp
field to struct ceph_osd_request that will hold the time of that
the reply was received. Use that to calculate the RTT for each call,
and divide the sum of those by number of calls to get averate RTT.

Keep a tally of RTT for OSD writes and number of calls to track average
latency of OSD writes.

URL: https://tracker.ceph.com/issues/43215
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:51 +02:00
Xiubo Li
1af16d547f ceph: add caps perf metric for each superblock
Count hits and misses in the caps cache. If the client has all of
the necessary caps when a task needs references, then it's counted
as a hit. Any other situation is a miss.

URL: https://tracker.ceph.com/issues/43215
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:51 +02:00
Xiubo Li
f9009efac4 ceph: add dentry lease metric support
For dentry leases, only count the hit/miss info triggered from the vfs
calls. For the cases like request reply handling and ceph_trim_dentries,
ignore them.

For now, these are only viewable using debugfs. Future patches will
allow the client to send the stats to the MDS.

The output looks like:

item          total           miss            hit
-------------------------------------------------
d_lease       11              7               141

URL: https://tracker.ceph.com/issues/43215
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-06-01 13:22:51 +02:00
Steve French
adbb2dafe7 cifs: minor fix to two debug messages
Joe Perches pointed out that we were missing a newline
at the end of two debug messages

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Joe Perches
a0a3036b81 cifs: Standardize logging output
Use pr_fmt to standardize all logging for fs/cifs.

Some logging output had no CIFS: specific prefix.

Now all output has one of three prefixes:

o CIFS:
o CIFS: VFS:
o Root-CIFS:

Miscellanea:

o Convert printks to pr_<level>
o Neaten macro definitions
o Remove embedded CIFS: prefixes from formats
o Convert "illegal" to "invalid"
o Coalesce formats
o Add missing '\n' format terminations
o Consolidate multiple cifs_dbg continuations into single calls
o More consistent use of upper case first word output logging
o Multiline statement argument alignment and wrapping

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Steve French
82e9367c43 smb3: Add new parm "nodelete"
In order to handle workloads where it is important to make sure that
a buggy app did not delete content on the drive, the new mount option
"nodelete" allows standard permission checks on the server to work,
but prevents on the client any attempts to unlink a file or delete
a directory on that mount point.  This can be helpful when running
a little understood app on a network mount that contains important
content that should not be deleted.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-06-01 00:10:18 -05:00
Ronnie Sahlberg
b2ca6c2c9e cifs: move some variables off the stack in smb2_ioctl_query_info
Move some large data structures off the stack and into dynamically
allocated memory in the function smb2_ioctl_query_info

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Ronnie Sahlberg
a7d5c29462 cifs: reduce stack use in smb2_compound_op
Move a lot of structures and arrays off the stack and into a dynamically
allocated structure instead.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Paulo Alcantara
baf3f08ef4 cifs: get rid of unused parameter in reconn_setup_dfs_targets()
The target iterator parameter "it" is not used in
reconn_setup_dfs_targets(), so just remove it.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Paulo Alcantara
e4af35fa55 cifs: handle hostnames that resolve to same ip in failover
In order to support reconnect to hostnames that resolve to same ip
address, besides relying on the currently set hostname to match DFS
targets, attempt to resolve the targets and then match their addresses
with the reconnected server ip address.

For instance, if we have two hostnames "FOO" and "BAR", and both
resolve to the same ip address, we would be able to handle failover in
DFS paths like

    \\FOO\dfs\link1 -> [ \BAZ\share2 (*), \BAR\share1 ]
    \\FOO\dfs\link2 -> [ \BAZ\share2 (*), \FOO\share1 ]

so when "BAZ" is no longer accessible, link1 and link2 would get
reconnected despite having different target hostnames.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Paulo Alcantara
aaa3aef34d cifs: set up next DFS target before generic_ip_connect()
If we mount a very specific DFS link

    \\FS0.FOO.COM\dfs\link -> \FS0\share1, \FS1\share2

where its target list contains NB names ("FS0" & "FS1") rather than
FQDN ones ("FS0.FOO.COM" & "FS1.FOO.COM"), we end up connecting to
\FOO\share1 but server->hostname will have "FOO.COM".  The reason is
because both "FS0" and "FS0.FOO.COM" resolve to same IP address and
they share same TCP server connection, but "FS0.FOO.COM" was the first
hostname set -- which is OK.

However, if the echo thread timeouts and we still have a good
connection to "FS0", in cifs_reconnect()

    rc = generic_ip_connect(server) -> success
    if (rc) {
            ...
            reconn_inval_dfs_target(server, cifs_sb, &tgt_list,
	                            &tgt_it);
            ...
     }
     ...

it successfully reconnects to "FS0" server but does not set up next
DFS target - which should be the same target server "\FS0\share1" -
and server->hostname remains set to "FS0.FOO.COM" rather than "FS0",
as reconn_inval_dfs_target() would have it set to "FS0" if called
earlier.

Finally, in __smb2_reconnect(), the reconnect of tcons would fail
because tcon->ses->server->hostname (FS0.FOO.COM) does not match DFS
target's hostname (FS0).

Fix that by calling reconn_inval_dfs_target() before
generic_ip_connect() so server->hostname will get updated correctly
prior to reconnecting its tcons in __smb2_reconnect().

With "cifs: handle hostnames that resolve to same ip in failover"
patch

    - The above problem would not occur.
    - We could save an DNS query to find out that they both resolve to
      the same ip address.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Colin Ian King
136a5dc330 cifs: remove redundant initialization of variable rc
The variable rc is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Kenneth D'souza
8fd6e1d694 cifs: handle "nolease" option for vers=1.0
The "nolease" mount option is only supported for SMB2+ mounts.
Fail with appropriate error message if vers=1.0 option is passed.

Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:17 -05:00
Kees Cook
f8feafeaee pstore/blk: Introduce "best_effort" mode
In order to use arbitrary block devices as a pstore backend, provide a
new module param named "best_effort", which will allow using any block
device, even if it has not provided a panic_write callback.

Link: https://lore.kernel.org/lkml/20200511233229.27745-12-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-31 19:49:01 -07:00
WeiXiong Liao
7dcb7848ba pstore/blk: Support non-block storage devices
Add support for non-block devices (e.g. MTD). A non-block driver calls
pstore_blk_register_device() to register iself.

In addition, pstore/zone is updated to handle non-block devices,
where an erase must be done before a write. Without this, there is no
way to remove records stored to an MTD.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-10-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-31 19:49:00 -07:00
WeiXiong Liao
1525fb3bb6 pstore/blk: Provide way to query pstore configuration
In order to configure itself, the MTD backend needs to be able to query
the current pstore configuration. Introduce pstore_blk_get_config() for
this purpose.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-9-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-31 19:49:00 -07:00
WeiXiong Liao
335426c6dc pstore/zone: Provide way to skip "broken" zone for MTD devices
One requirement to support MTD devices in pstore/zone is having a
way to declare certain regions as broken. Add this support to
pstore/zone.

The MTD driver should return -ENOMSG when encountering a bad region,
which tells pstore/zone to skip and try the next one.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-8-keescook@chromium.org/
Co-developed-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: //lore.kernel.org/lkml/20200512173801.222666-1-colin.king@canonical.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-31 19:48:56 -07:00
David S. Miller
1806c13dc2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.

The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-31 17:48:46 -07:00
David Howells
a310082f6d afs: Rename struct afs_fs_cursor to afs_operation
As a prelude to implementing asynchronous fileserver operations in the afs
filesystem, rename struct afs_fs_cursor to afs_operation.

This struct is going to form the core of the operation management and is
going to acquire more members in later.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:52 +01:00
David Howells
7126ead910 afs: Remove the error argument from afs_protocol_error()
Remove the error argument from afs_protocol_error() as it's always
-EBADMSG.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:52 +01:00
David Howells
38355eec6a afs: Set error flag rather than return error from file status decode
Set a flag in the call struct to indicate an unmarshalling error rather
than return and handle an error from the decoding of file statuses.  This
flag is checked on a successful return from the delivery function.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
8230fd8217 afs: Make callback processing more efficient.
afs_vol_interest objects represent the volume IDs currently being accessed
from a fileserver.  These hold lists of afs_cb_interest objects that
repesent the superblocks using that volume ID on that server.

When a callback notification from the server telling of a modification by
another client arrives, the volume ID specified in the notification is
looked up in the server's afs_vol_interest list.  Through the
afs_cb_interest list, the relevant superblocks can be iterated over and the
specific inode looked up and marked in each one.

Make the following efficiency improvements:

 (1) Hold rcu_read_lock() over the entire processing rather than locking it
     each time.

 (2) Do all the callbacks for each vid together rather than individually.
     Each volume then only needs to be looked up once.

 (3) afs_vol_interest objects are now stored in an rb_tree rather than a
     flat list to reduce the lookup step count.

 (4) afs_vol_interest lookup is now done with RCU, but because it's in an
     rb_tree which may rotate under us, a seqlock is used so that if it
     changes during the walk, we repeat the walk with a lock held.

With this and the preceding patch which adds RCU-based lookups in the inode
cache, target volumes/vnodes can be taken without the need to take any
locks, except on the target itself.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
6d043a5782 afs: Show more information in /proc/net/afs/servers
Show more information in /proc/net/afs/servers to make it easier to see
what's going on with the server probing.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
f6cbb368bc afs: Actively poll fileservers to maintain NAT or firewall openings
When an AFS client accesses a file, it receives a limited-duration callback
promise that the server will notify it if another client changes a file.
This callback duration can be a few hours in length.

If a client mounts a volume and then an application prevents it from being
unmounted, say by chdir'ing into it, but then does nothing for some time,
the rxrpc_peer record will expire and rxrpc-level keepalive will cease.

If there is NAT or a firewall between the client and the server, the route
back for the server may close after a comparatively short duration, meaning
that attempts by the server to notify the client may then bounce.

The client, however, may (so far as it knows) still have a valid unexpired
promise and will then rely on its cached data and will not see changes made
on the server by a third party until it incidentally rechecks the status or
the promise needs renewal.

To deal with this, the client needs to regularly probe the server.  This
has two effects: firstly, it keeps a route open back for the server, and
secondly, it causes the server to disgorge any notifications that got
queued up because they couldn't be sent.

Fix this by adding a mechanism to emit regular probes.

Two levels of probing are made available: Under normal circumstances the
'slow' queue will be used for a fileserver - this just probes the preferred
address once every 5 mins or so; however, if server fails to respond to any
probes, the server will shift to the 'fast' queue from which all its
interfaces will be probed every 30s.  When it finally responds, the record
will switch back to the slow queue.

Further notes:

 (1) Probing is now no longer driven from the fileserver rotation
     algorithm.

 (2) Probes are dispatched to all interfaces on a fileserver when that an
     afs_server object is set up to record it.

 (3) The afs_server object is removed from the probe queues when we start
     to probe it.  afs_is_probing_server() returns true if it's not listed
     - ie. it's undergoing probing.

 (4) The afs_server object is added back on to the probe queue when the
     final outstanding probe completes, but the probed_at time is set when
     we're about to launch a probe so that it's not dependent on the probe
     duration.

 (5) The timer and the work item added for this must be handed a count on
     net->servers_outstanding, which they hand on or release.  This makes
     sure that network namespace cleanup waits for them.

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Dave Botsch <botsch@cnf.cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
977e5f8ed0 afs: Split the usage count on struct afs_server
Split the usage count on the afs_server struct to have an active count that
registers who's actually using it separately from the reference count on
the object.

This allows a future patch to dispatch polling probes without advancing the
"unuse" time into the future each time we emit a probe, which would
otherwise prevent unused server records from expiring.

Included in this:

 (1) The latter part of afs_destroy_server() in which the RCU destruction
     of afs_server objects is invoked and the outstanding server count is
     decremented is split out into __afs_put_server().

 (2) afs_put_server() now calls __afs_put_server() rather then setting the
     management timer.

 (3) The calls begun by afs_fs_give_up_all_callbacks() and
     afs_fs_get_capabilities() can now take a ref on the server record, so
     afs_destroy_server() can just drop its ref and needn't wait for the
     completion of these calls.  They'll put the ref when they're done.

 (4) Because of (3), afs_fs_probe_done() no longer needs to wake up
     afs_destroy_server() with server->probe_outstanding.

 (5) afs_gc_servers can be simplified.  It only needs to check if
     server->active is 0 rather than playing games with the refcount.

 (6) afs_manage_servers() can propose a server for gc if usage == 0 rather
     than if ref == 1.  The gc is effected by (5).

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
8100680592 afs: Use the serverUnique field in the UVLDB record to reduce rpc ops
The U-version VLDB volume record retrieved by the VL.GetEntryByNameU rpc op
carries a change counter (the serverUnique field) for each fileserver
listed in the record as backing that volume.  This is incremented whenever
the registration details for a fileserver change (such as its address
list).  Note that the same value will be seen in all UVLDB records that
refer to that fileserver.

This should be checked before calling the VL server to re-query the address
list for a fileserver.  If it's the same, there's no point doing the query.

Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
13fcc6356a afs: Always include dir in bulk status fetch from afs_do_lookup()
When a lookup is done in an AFS directory, the filesystem will speculate
and fetch up to 49 other statuses for files in the same directory and fetch
those as well, turning them into inodes or updating inodes that already
exist.

However, occasionally, a callback break might go missing due to NAT timing
out, but the afs filesystem doesn't then realise that the directory is not
up to date.

Alleviate this by using one of the status slots to check the directory in
which the lookup is being done.

Reported-by: Dave Botsch <botsch@cnf.cornell.edu>
Suggested-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31 15:19:51 +01:00
David Howells
3f19b2ab97 vfs, afs, ext4: Make the inode hash table RCU searchable
Make the inode hash table RCU searchable so that searches that want to
access or modify an inode without taking a ref on that inode can do so
without taking the inode hash table lock.

The main thing this requires is some RCU annotation on the list
manipulation operations.  Inodes are already freed by RCU in most cases.

Users of this interface must take care as the inode may be still under
construction or may be being torn down around them.

There are at least three instances where this can be of use:

 (1) Testing whether the inode number iunique() is going to return is
     currently unique (the iunique_lock is still held).

 (2) Ext4 date stamp updating.

 (3) AFS callback breaking.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
cc: linux-ext4@vger.kernel.org
cc: linux-afs@lists.infradead.org
2020-05-31 15:19:44 +01:00
WeiXiong Liao
649304c936 Documentation: Add details for pstore/blk
Add details on using pstore/blk, the new backend of pstore to record
dumps to block devices, in Documentation/admin-guide/pstore-blk.rst

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-7-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
WeiXiong Liao
34327e9fd2 pstore/zone,blk: Add ftrace frontend support
Support backend for ftrace. To enable ftrace backend, just make
ftrace_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-6-keescook@chromium.org/
Co-developed-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/lkml/20200512170719.221514-1-colin.king@canonical.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
WeiXiong Liao
cc9c4d1b55 pstore/zone,blk: Add console frontend support
Support backend for console. To enable console backend, just make
console_size be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-5-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
WeiXiong Liao
0dc068265a pstore/zone,blk: Add support for pmsg frontend
Add pmsg support to pstore/blk (through pstore/zone). To enable, pmsg_size
must be greater than 0 and a multiple of 4096.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-4-keescook@chromium.org/
Co-developed-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/lkml/20200512171932.222102-1-colin.king@canonical.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
WeiXiong Liao
17639f67c1 pstore/blk: Introduce backend for block devices
pstore/blk is similar to pstore/ram, but uses a block device as the
storage rather than persistent ram.

The pstore/blk backend solves two common use-cases that used to preclude
using pstore/ram:
- not all devices have a battery that could be used to persist
  regular RAM across power failures.
- most embedded intelligent equipment have no persistent ram, which
  increases costs, instead preferring cheaper solutions, like block
  devices.

pstore/blk provides separate configurations for the end user and for the
block drivers. User configuration determines how pstore/blk operates, such
as record sizes, max kmsg dump reasons, etc. These can be set by Kconfig
and/or module parameters, but module parameter have priority over Kconfig.
Driver configuration covers all the details about the target block device,
such as total size of the device and how to perform read/write operations.
These are provided by block drivers, calling pstore_register_blkdev(),
including an optional panic_write callback used to bypass regular IO
APIs in an effort to avoid potentially destabilized kernel code during
a panic.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-3-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00
WeiXiong Liao
d26c3321fe pstore/zone: Introduce common layer to manage storage zones
Implement a common set of APIs needed to support pstore storage zones,
based on how ramoops is designed. This will be used by pstore/blk with
the intention of migrating pstore/ram in the future.

Signed-off-by: WeiXiong Liao <liaoweixiong@allwinnertech.com>
Link: https://lore.kernel.org/lkml/20200511233229.27745-2-keescook@chromium.org/
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30 10:34:03 -07:00