This allows bumping threadcount without taking the global devmtx lock.
In particular this eliminates contention on said lock while using bhyve
with multiple vms.
Reviewed by: kib
Tested by: markj
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22548
Add a warning when a device registers with devfs and requests
D_NEEDGIANT. The warning says the device will go away before
13.0. This is needed to flush out the devices in the tree that are
still Giant locked. This warning, or some variant of it, should have
gone into the tree a long time ago...
The intention is to require all devices be converted to not use
automatic giant in this way, or remove any such devices that remain
that we don't have the hardware to test a conversion of.
kbd so far is the only device that can't leave the tree, yet needs
something sensible done to avoid the auto giant lock (even if it is
just doing the wrapping itself). There may be others added to this
list... Any discussions of this topic will take place on arch@.
SI_CHEAPCLONE was introduced in r66067 for use with cloned bpfs. It was
later also used in tty, tun, tap at points. The rough timeline for being
removed in each of these is as follows:
- r181690: bpf switched to use cdevpriv API by ed@
- r181905: ed@ rewrote the TTY later to be mpsafe
- r204464: kib@ removes it from tun/tap, declaring it unused
I've not yet been able to dig up any other consumers in the intervening 9
years. It is no longer set on any devices in the tree and leaves an
interesting situation in make_dev_sv where we're ok with the device already
being set SI_NAMED.
Attempting to initialize si_drv{1,2} with mda_si_drv{1,2} does not work if
you are operating on cloned devices.
clone_create must be called prior to the make_dev* family to create/return
the device on the clonelist as needed. This device is later returned early
in newdev(), prior to si_drv{0,1,2} initialization.
This patch simply breaks out of the loop if we've found a device and
finishes init.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21904
This includes the bump for cdevsw d_version. Otherwise, the impact on
the ABI (not KBI) is surprisingly low. The most important affected
interface is devname(3) and ttyname(3) which already correctly handle
long names (and ttyname(3) should not be affected at all).
Still, due to the d_version bump, I argue that the change is not MFC-able.
Requested by: mmacy
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D18932
Like the companion API devvn_refthread, leave *ref uninitialized when a
reference was not acquired. Initializing to 1 provides a vaguely
correct-looking but bogus value for broken callers to (mistakenly) pass to
dev_relthread() when refthread fails.
Make it even more clear to consumers that dev_relthread is only valid when
dev_refthread succeeds.
Reviewed by: kib, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16885
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Immediate problem fixed by the new KPI is the long-standing race
between device creation and assignments to cdev->si_drv1 and
cdev->si_drv2, which allows the window where cdevsw methods might be
called with si_drv1,2 fields not yet set. Devices typically checked
for NULL and returned spurious errors to usermode, and often left some
methods unchecked.
The new function interface is designed to be extensible, which should
allow to add more features to make_dev_s(9) without inventing yet
another name for function to create devices, while maintaining KPI and
even KBI backward-compatibility.
Reviewed by: hps, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D4746
delist_dev() function. In addition to this change:
- add a proper description of this function
- add a proper witness assert inside this function
- switch a nearby line to use the "cdp" pointer instead of cdev2priv()
MFC after: 3 days
in r277199. Acquire the neccessary reference in delist_dev_locked()
and inform destroy_devl() about it using CDP_UNREF_DTR flag.
Fix some style nits, add asserts.
Discussed with: hselasky
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
"delist_dev()" function. Make sure the character device structure
doesn't go away until the end of the "destroy_dev()" function due to
concurrently running cleanup code inside "devfs_populate()".
MFC after: 1 week
Reported by: dchagin@
sys/kern/kern_conf.c:
Add make_dev_physpath_alias(). This interface takes
the parent cdev of the alias, an old alias cdev (if any)
to replace with the newly created alias, and the physical
path string. The alias is visiable as a symlink to the
parent, with the same name as the parent, rooted at
physpath in devfs.
Note: make_dev_physpath_alias() has hard coded knowledge of the
Solaris style prefix convention for physical path data,
"id1,". In the future, I expect the convention to change
to allow "physical path quality" to be reported in the
prefix. For example, a physical path based on NewBus
topology would be of "lower quality" than a physical path
reported by a device enclosure.
Sponsored by: Spectra Logic Corporation
and destroy_devl() drops dev_mtx. The protection against the race
with dev_rel(), introduced in r163328, should be extended to cover
destroy_devl() calls for the children of the destroyed dev.
Reported and tested by: joerg
MFC after: 1 week
A new function prep_devname() sanitizes a device name by removing
leading and redundant sequential slashes. The function returns an error
for names which already exist or are considered invalid.
A new flag MAKEDEV_CHECKNAME for make_dev_p(9) and make_dev_credf(9)
indicates that the caller is prepared to handle an error related to the
device name. An invalid name triggers a panic if the flag is not
specified.
Document the MAKEDEV_CHECKNAME flag in the make_dev(9) manual page.
Idea from: kib
Reviewed by: kib
cdev will never be destroyed. Propagate the flag to devfs vnodes as
VV_ETERNVALDEV. Use the flags to avoid acquiring devmtx and taking a
thread reference on such nodes.
In collaboration with: pho
MFC after: 1 month
New code that creates character devices shouldn't use device unit
numbers, but only si_drv[12] to hold pointer to per-device data. Make
this function more future proof by removing the unit number argument.
Discussed with: kib
in a no-sleep context. If resource allocation cannot be done without
sleep, make_dev_credf() fails and returns NULL.
Reviewed by: jh
MFC after: 2 weeks
This replaces d_mmap() with the d_mmap2() implementation and also
changes the type of offset to vm_ooffset_t.
Purge d_mmap2().
All driver modules will need to be rebuilt since D_VERSION is also
bumped.
Reviewed by: jhb@
MFC after: Not in this lifetime...
Fix some wrong usages.
Note: this does not affect generated binaries as this argument is not used.
PR: 137213
Submitted by: Eygene Ryabinkin (initial version)
MFC after: 1 month
pages in an object.
- Add a new variant of d_mmap() currently called d_mmap2() which accepts
an additional in/out parameter that is the memory attribute to use for
the requested page.
- A driver either uses d_mmap() or d_mmap2() for all requests but not both.
The current implementation uses a flag in the cdevsw (D_MMAP2) to indicate
that the driver provides a d_mmap2() handler instead of d_mmap(). This
is done to make the change ABI compatible with existing drivers and
MFC'able to 7 and 8.
Submitted by: alc
MFC after: 1 month
device drivers to use arbitrary VM objects to satisfy individual mmap()
requests.
- A new d_mmap_single(cdev, &foff, objsize, &object, prot) callback is
added to cdevsw. This function is called for each mmap() request.
If it returns ENODEV, then the mmap() request will fall back to using
the device's device pager object and d_mmap(). Otherwise, the method
can return a VM object to satisfy this entire mmap() request via
*object. It can also modify the starting offset into this object via
*foff. This allows device drivers to use the file offset as a cookie
to identify specific VM objects.
- vm_mmap_vnode() has been changed to call vm_mmap_cdev() directly when
mapping V_CHR vnodes. This avoids duplicating all the cdev mmap
handling code and simplifies some of vm_mmap_vnode().
- D_VERSION has been bumped to D_VERSION_02. Older device drivers
using D_VERSION_01 are still supported.
MFC after: 1 month
the behaviour alredy present with the further malloc() call in
devctl_notify().
This fixes a bug in the CAM layer where the camisr handler finished to
call camperiphfree() (and subsequently destroy_dev() resulting in a new
dev notify) while the xpt lock is held.
PR: kern/130330
Tested by: Riccardo Torrini <riccardo dot torrini at esaote dot com>
In the good old days it was possible to have dev_t's that referred to
nonexistent devices. In these cases devtoname() automatically generated
names. This is no longer possible, so remove this dead code.
Discussed with: kib
Remove the `udev' variable, which has a different type than the original
function argument and si_drv0. The `udev' name is also misleading,
because it is not the number returned by dev2udev(). Rename this
argument to `unit'. It is the same number as returned by dev2unit().
We should still access si_drv0 using dev2unit(). Also change the
KASSERT() to really print the udev instead of the unit number. I suspect
it's still useful to print the unit number, especially for devices that
use clone lists, so keep the unit number in the panic string.
