in the future in a backward compatible (API and ABI) way.
The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.
The structure definition looks like this:
struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};
The initial CAP_RIGHTS_VERSION is 0.
The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.
The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.
To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.
#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)
We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:
#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)
#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)
There is new API to manage the new cap_rights_t structure:
cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);
bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:
cap_rights_t rights;
cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);
There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:
#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);
Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:
cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);
Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.
This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.
Sponsored by: The FreeBSD Foundation
of relying on the tvtohz() workaround. The latter has been introduced
lately by jhb@ (r254699) in order to have a fix that can be backported
to STABLE.
Reported by: Vitja Makarov <vitja.makarov at gmail dot com>
Reviewed by: jhb (earlier version)
waiting for an RPC reply from the server while holding the mount
point busy (mnt_lockref incremented). This happens because dounmount()
msleep()s waiting for mnt_lockref to become 0, before calling
VFS_UNMOUNT(). This patch adds a new VFS operation called VFS_PURGE(),
which the NFS client implements as purging RPCs in progress. Making
this call before checking mnt_lockref fixes the problem, by ensuring
that the VOP_xxx() calls will fail and unbusy the mount point.
Reported by: sbruno
Reviewed by: kib
MFC after: 2 weeks
- Remove excessive parenthesis
- Use KNF continuation indentation
- Cut down on excessive continuation lines
- More consistent style in messages
- Use uprintf() instead of printf()
Submitted by: bde
problems with the way MLEN, MHLEN, and struct mbuf are set up.
CTASSERT's are provided to detect such issues at compile time in the
future.
The #define MLEN and MHLEN calculation do not take actual compiler-
induced alignment and padding inside the complete struct mbuf into
account. Accordingly appropriate attention is required when changing
members of struct mbuf.
Ideally one would calculate MLEN as (MSIZE - sizeof(((struct mbuf *)0)->m_hdr)
but that doesn't work as the compiler refuses to operate on an as of
yet incomplete structure.
In particular ARM 32bit has more strict alignment requirements which
caused 4 bytes of padding between m_hdr and pkthdr in struct mbuf
because of the 64bit members in pkthdr. This wasn't picked up by MLEN
and MHLEN causing an overflow of the mbuf provided data storage by
overestimating its size.
I386 didn't show this problem because it handles unaligned access just
fine, albeit at a small performance penalty.
On 64bit architectures the struct mbuf layout is 64bit aligned in all
places.
Reported by: Thomas Skibo <ThomasSkibo-at-sbcglobal-dot-net>
Tested by: tuexen, ian, Thomas Skibo (extended patch)
Sponsored by: The FreeBSD Foundation
for the available pbuf when passed vnode is backing md(4). Other i/o
directed to the same md device might already hold pbufs, and then we
could deadlock since only our progress can free a pbuf needed for
wakeup.
Obtained from: projects/vm6
Reminded and tested by: pho
MFC after: 1 week
ps(1) utility, e.g. "ps -O fib".
bin/ps/keyword.c:
Add the "fib" keyword and default its column name to "FIB".
bin/ps/ps.1:
Add "fib" as a supported keyword.
sys/compat/freebsd32/freebsd32.h:
sys/kern/kern_proc.c:
sys/sys/user.h:
Add the default fib number for a process (p->p_fibnum)
to the user land accessible process data of struct kinfo_proc.
Submitted by: Oliver Fromme <olli@fromme.com>, gibbs
external mbuf buffer management capabilities in the future.
For now only EXT_FREE_OK is defined with current legacy behavior.
Sponsored by: The FreeBSD Foundation
kld_unload event handler which gets invoked after a linker file has been
successfully unloaded. The kld_unload and kld_load event handlers are now
invoked with the shared linker lock held, while kld_unload_try is invoked
with the lock exclusively held.
Convert hwpmc(4) to use these event handlers instead of having
kern_kldload() and kern_kldunload() invoke hwpmc(4) hooks whenever files are
loaded or unloaded. This has no functional effect, but simplifes the linker
code somewhat.
Reviewed by: jhb
2 predictable branches nowadays. However as a pre-condition the
caller had to ensure that the mbuf pkthdr did not have any mtags
attached to it, costing some potential branches again.
Sponsored by: The FreeBSD Foundation
linker_init_kernel_modules() and linker_preload() in order to remove most
of the checks for !cold before asserting that the kld lock is held. These
routines are invoked by SYSINIT(9), so there's no harm in them taking the
kld lock.
features. The changes in particular are:
o Remove rarely used "header" pointer and replace it with a 64bit protocol/
layer specific union PH_loc for local use. Protocols can flexibly overlay
their own 8 to 64 bit fields to store information while the packet is
worked on.
o Mechanically convert IP reassembly, IGMP/MLD and ATM to use pkthdr.PH_loc
instead of pkthdr.header.
o Extend csum_flags to 64bits to allow for additional future offload
information to be carried (e.g. iSCSI, IPsec offload, and others).
o Move the RSS hash type enumerator from abusing m_flags to its own 8bit
rsstype field. Adjust accessor macros.
o Add cosqos field to store Class of Service / Quality of Service information
with the packet. It is not yet supported in any drivers but allows us to
get on par with Cisco/Juniper in routing applications (plus MPLS QoS) with
a modernized ALTQ.
o Add four 8 bit fields l[2-5]hlen to store the relative header offsets
from the start of the packet. This is important for various offload
capabilities and to relieve the drivers from having to parse the packet
and protocol headers to find out location of checksums and other
information. Header parsing in drivers is a lot of copy-paste and
unhandled corner cases which we want to avoid.
o Add another flexible 64bit union to map various additional persistent
packet information, like ether_vtag, tso_segsz and csum fields.
Depending on the csum_flags settings some fields may have different usage
making it very flexible and adaptable to future capabilities.
o Restructure the CSUM flags to better signify their outbound (down the
stack) and inbound (up the stack) use. The CSUM flags used to be a bit
chaotic and rather poorly documented leading to incorrect use in many
places. Bring clarity into their use through better naming.
Compatibility mappings are provided to preserve the API. The drivers
can be corrected one by one and MFC'd without issue.
o The size of pkthdr stays the same at 48/56bytes (32/64bit architectures).
Sponsored by: The FreeBSD Foundation
free function access to the mbuf the external memory was attached
to.
Mechanically adjust all users to include the mbuf parameter.
This fixes a long standing annoyance for external free functions.
Before one had to sacrifice one of the argument pointers for this.
Sponsored by: The FreeBSD Foundation
Remove locking from taskqueue_member(). The list of threads is static
during the taskqueue life cycle, so there is no need to protect it,
taking quite congested lock several more times for each ZFS I/O.
to 8 bits. ext_type is an enumerator and the number of types we
have is a mere dozen.
A couple of ext_types are renumbered to fit within 8 bits.
EXT_VENDOR[1-4] and EXT_EXP[1-4] types for vendor-internal and
experimental local mapping.
The ext_flags field is currently unused but has a couple of flags
already defined for future use. Again vendor and experimental
flags are provided for local mapping.
EXT_FLAG_BITS is provided for the printf(9) %b identifier.
Initialize and copy ext_flags in the relevant mbuf functions.
Improve alignment and packing of struct m_ext on 32 and 64 archs
by carefully sorting the fields.
configure sa(4) to request no I/O splitting by default.
For tape devices, the user needs to be able to clearly understand
what blocksize is actually being used when writing to a tape
device. The previous behavior of physio(9) was that it would split
up any I/O that was too large for the device, or too large to fit
into MAXPHYS. This means that if, for instance, the user wrote a
1MB block to a tape device, and MAXPHYS was 128KB, the 1MB write
would be split into 8 128K chunks. This would be done without
informing the user.
This has suboptimal effects, especially when trying to communicate
status to the user. In the event of an error writing to a tape
(e.g. physical end of tape) in the middle of a 1MB block that has
been split into 8 pieces, the user could have the first two 128K
pieces written successfully, the third returned with an error, and
the last 5 returned with 0 bytes written. If the user is using
a standard write(2) system call, all he will see is the ENOSPC
error. He won't have a clue how much actually got written. (With
a writev(2) system call, he should be able to determine how much
got written in addition to the error.)
The solution is to prevent physio(9) from splitting the I/O. The
new cdev flag, SI_NOSPLIT, tells physio that the driver does not
want I/O to be split beforehand.
Although the sa(4) driver now enables SI_NOSPLIT by default,
that can be disabled by two loader tunables for now. It will not
be configurable starting in FreeBSD 11.0. kern.cam.sa.allow_io_split
allows the user to configure I/O splitting for all sa(4) driver
instances. kern.cam.sa.%d.allow_io_split allows the user to
configure I/O splitting for a specific sa(4) instance.
There are also now three sa(4) driver sysctl variables that let the
users see some sa(4) driver values. kern.cam.sa.%d.allow_io_split
shows whether I/O splitting is turned on. kern.cam.sa.%d.maxio shows
the maximum I/O size allowed by kernel configuration parameters
(e.g. MAXPHYS, DFLTPHYS) and the capabilities of the controller.
kern.cam.sa.%d.cpi_maxio shows the maximum I/O size supported by
the controller.
Note that a better long term solution would be to implement support
for chaining buffers, so that that MAXPHYS is no longer a limiting
factor for I/O size to tape and disk devices. At that point, the
controller and the tape drive would become the limiting factors.
sys/conf.h: Add a new cdev flag, SI_NOSPLIT, that allows a
driver to tell physio not to split up I/O.
sys/param.h: Bump __FreeBSD_version to 1000049 for the addition
of the SI_NOSPLIT cdev flag.
kern_physio.c: If the SI_NOSPLIT flag is set on the cdev, return
any I/O that is larger than si_iosize_max or
MAXPHYS, has more than one segment, or would have
to be split because of misalignment with EFBIG.
(File too large).
In the event of an error, print a console message to
give the user a clue about what happened.
scsi_sa.c: Set the SI_NOSPLIT cdev flag on the devices created
for the sa(4) driver by default.
Add tunables to control whether we allow I/O splitting
in physio(9).
Explain in the comments that allowing I/O splitting
will be deprecated for the sa(4) driver in FreeBSD
11.0.
Add sysctl variables to display the maximum I/O
size we can do (which could be further limited by
read block limits) and the maximum I/O size that
the controller can do.
Limit our maximum I/O size (recorded in the cdev's
si_iosize_max) by MAXPHYS. This isn't strictly
necessary, because physio(9) will limit it to
MAXPHYS, but it will provide some clarity for the
application.
Record the controller's maximum I/O size reported
in the Path Inquiry CCB.
sa.4: Document the block size behavior, and explain that
the option of allowing physio(9) to split the I/O
will disappear in FreeBSD 11.0.
Sponsored by: Spectra Logic
does not make sense to wait for the soft busy state of the page to
drain. The vm object lock is dropped immediately after, so the result
of the wait is invalidated.
It might make sense to not wait for the hard busy state as well,
esp. for the fully valid page, but this is postponed for now.
Reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
than using a home-rolled version. The home-rolled version could result
in shorter-than-requested sleeps.
Reported by: Vitja Makarov <vitja.makarov@gmail.com>
MFC after: 2 weeks
shared busy without first draining the hard busy state. Previously it
went unnoticed since VPO_BUSY and m->busy fields were distinct, and
vm_page_io_start() did not verified that the passed page has VPO_BUSY
flag cleared, but such page state is wrong. New implementation is
more strict and catched this case.
Drain the busy state as needed, before calling vm_page_sbusy().
Tested by: pho, jkim
Sponsored by: The FreeBSD Foundation
The flag was mandatory since r209792, where vm_page_grab(9) was
changed to only support the alloc retry semantic.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
Add MAC framework entries for posix shm read and write.
Do not allow implicit extension of the underlying memory segment past
the limit set by ftruncate(2) by either of the syscalls. Read and
write returns short i/o, lseek(2) fails with EINVAL when resulting
offset does not fit into the limit.
Discussed with: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
that don't support superpages. This keeps the number of spans and internal
fragmentation lower.
- When the user asks for alignment from vmem_xalloc adjust the imported size
by 2*align to be certain we can satisfy the allocation. This comes at
the expense of potential failures when the backend can't supply enough
memory but could supply the requested size and alignment.
Sponsored by: EMC / Isilon Storage Division
for a very long time, if ever.
Should such a functionality ever be needed again the appropriate and
much better way to do it is through a custom EXT_SOMETHING external mbuf
type together with a dedicated *ext_free function.
Discussed with: trociny, glebius
