After region and linecard lock removals, this helper is always supposed
to be called with instance lock held. So put the assertion here and
remove the comment which is no longer accurate.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
devlink_dump_for_each_instance_get() is currently called from
a single place in netlink.c. As there is no need to use
this helper anywhere else in the future, remove it and
call devlinks_xa_find_get() directly from while loop
in devlink_nl_instance_iter_dump(). Also remove redundant
idx clear on loop end as it is already done
in devlink_nl_instance_iter_dump().
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Benefit from recently introduced instance iteration and convert
reporters .dumpit generic netlink callback to use it.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Benefit from recently introduced instance iteration and convert
linecards .dumpit generic netlink callback to use it.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Similar to other devlink objects, rely on devlink instance lock
and remove object specific reporters_lock.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As long as the linecard life time is protected by devlink instance
lock, the reference counting is no longer needed. Remove it.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Similar to other devlink objects, convert the linecards list to be
protected by devlink instance lock. Alongside with that rename the
create/destroy() functions to devl_* to indicate the devlink instance
lock needs to be held while calling them.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The reference needs to keep the instance memory around, but also
the instance lock must remain valid. Users will take the lock,
check registration status and release the lock. mutex_destroy()
etc. belong in the same place as the freeing of the memory.
Unfortunately lockdep_unregister_key() sleeps so we need
to switch the an rcu_work.
Note that the problem is a bit hard to repro, because
devlink_pernet_pre_exit() iterates over registered instances.
AFAIU the instances must get devlink_free()d concurrently with
the namespace getting deleted for the problem to occur.
Reported-by: syzbot+d94d214ea473e218fc89@syzkaller.appspotmail.com
Reported-by: syzbot+9f0dd863b87113935acf@syzkaller.appspotmail.com
Fixes: 9053637e0d ("devlink: remove the registration guarantee of references")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20230111042908.988199-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The objective of exposing the devlink instance locks to
drivers was to let them use these locks to prevent user space
from accessing the device before it's fully initialized.
This is difficult because devlink_unregister() waits for all
references to be released, meaning that devlink_unregister()
can't itself be called under the instance lock.
To avoid this issue devlink_register() was moved after subobject
registration a while ago. Unfortunately the netdev paths get
a hold of the devlink instances _before_ they are registered.
Ideally netdev should wait for devlink init to finish (synchronizing
on the instance lock). This can't work because we don't know if the
instance will _ever_ be registered (in case of failures it may not).
The other option of returning an error until devlink_register()
is called is unappealing (user space would get a notification
netdev exist but would have to wait arbitrary amount of time
before accessing some of its attributes).
Weaken the guarantees of the devlink references.
Holding a reference will now only guarantee that the memory
of the object is around. Another way of looking at it is that
the reference now protects the object not its "registered" status.
Use devlink instance lock to synchronize unregistration.
This implies that releasing of the "main" reference of the devlink
instance moves from devlink_unregister() to devlink_free().
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Always check under the instance lock whether the devlink instance
is still / already registered.
This is a no-op for the most part, as the unregistration path currently
waits for all references. On the init path, however, we may temporarily
open up a race with netdev code, if netdevs are registered before the
devlink instance. This is temporary, the next change fixes it, and this
commit has been split out for the ease of review.
Note that in case of iterating over sub-objects which have their
own lock (regions and line cards) we assume an implicit dependency
between those objects existing and devlink unregistration.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
devlink->dev is assumed to be always valid as long as any
outstanding reference to the devlink instance exists.
In prep for weakening of the references take the instance lock.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
xa_find_after() is designed to handle multi-index entries correctly.
If a xarray has two entries one which spans indexes 0-3 and one at
index 4 xa_find_after(0) will return the entry at index 4.
Having to juggle the two callbacks, however, is unnecessary in case
of the devlink xarray, as there is 1:1 relationship with indexes.
Always use xa_find() and increment the index manually.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon we'll have to check if a devlink instance is alive after
locking it. Convert to the by-instance dumping scheme to make
refactoring easier.
Most of the subobject code no longer has to worry about any devlink
locking / lifetime rules (the only ones that still do are the two subject
types which stubbornly use their own locking). Both dump and do callbacks
are given a devlink instance which is already locked and good-to-access
(do from the .pre_doit handler, dump from the new dump indirection).
Note that we'll now check presence of an op (e.g. for sb_pool_get)
under the devlink instance lock, that will soon be necessary anyway,
because we don't hold refs on the driver modules so the memory
in which ops live may be gone for a dead instance, after upcoming
locking changes.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Most dumpit implementations walk the devlink instances.
This requires careful lock taking and reference dropping.
Factor the loop out and provide just a callback to handle
a single instance dump.
Convert one user as an example, other users converted
in the next change.
Slightly inspired by ethtool netlink code.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use xarray id for cases of simple sub-object iteration.
We'll now use the state->instance for the devlink instances
and state->idx for subobject index.
Moving the definition of idx into the inner loop makes sense,
so while at it also move other sub-object local variables into
the loop.
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
xarray gives each devlink instance an id and allows us to restart
walk based on that id quite neatly. This is nice both from the
perspective of code brevity and from the stability of the dump
(devlink instances disappearing from before the resumption point
will not cause inconsistent dumps).
This patch takes care of simple cases where state->idx counts
devlink instances only.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Looks like devlinks_xa_find_get() was intended to get the mark
from the @filter argument. It doesn't actually use @filter, passing
DEVLINK_REGISTERED to xa_find_fn() directly. Walking marks other
than registered is unlikely so drop @filter argument completely.
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create a dump context structure instead of using cb->args
as an unsigned long array. This is a pure conversion which
is intended to be as much of a noop as possible.
Subsequent changes will use this to simplify the code.
The two non-trivial parts are:
- devlink_nl_cmd_health_reporter_dump_get_dumpit() checks args[0]
to see if devlink_fmsg_dumpit() has already been called (whether
this is the first msg), but doesn't use the exact value, so we
can drop the local variable there already
- devlink_nl_cmd_region_read_dumpit() uses args[0] for address
but we'll use args[1] now, shouldn't matter
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move out the netlink glue into a separate file.
Leave the ops in the old file because we'd have to export a ton
of functions. Going forward we should switch to split ops which
will let us to put the new ops in the netlink.c file.
Pure code move, no functional changes.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move core code into a separate file. It's spread around the main
file which makes refactoring and figuring out how devlink works
harder.
Move the xarray, all the most core devlink instance code out like
locking, ref counting, alloc, register, etc. Leave port stuff in
leftover.c, if we want to move port code it'd probably be to its
own file.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
