The problem is that g_access() must be called with the GEOM topology
lock held. And that gives a false impression that the lock is indeed
held across the call. But this isn't always true because many classes,
ZVOL being one of the many, need to drop the lock. It's either to
perform an I/O on the first open or to acquire a different lock (like in
g_mirror_access).
That, of course, can break many assumptions. For example,
g_slice_access() adds an extra exclusive count on the first open. As
described above, an underlying geom may drop the topology lock and that
would open a race with another thread that would also request another
extra exclusive count. In general, two consumers may be granted
incompatible accesses.
To avoid this problem the code is changed to mark a geom with special
flag before calling its access method and clear the flag afterwards. If
another thread sees that flag, then it means that the topology lock has
been dropped (either by the geom in question or downstream from it), so
it is not safe to make another access call. So, the second thread would
use g_topology_sleep() to wait until the flag is cleared and only then
would it proceed with the access.
Also see http://docs.freebsd.org/cgi/mid.cgi?809d9254-ee56-59d8-69a4-08838e985cea
PR: 225960
Reported by: asomers
Reviewed by: markj, mav
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D14533
If g_part_gpt_read() encountered a disk with bad primary and secondary
tables, it could leak memory.
Reported by: Coverity
Sponsored by: Dell EMC Isilon
to fix the memory leak that I introduced in r328426. Instead of
trying to clear up the possible memory leak in all the clients, I
ensure that it gets cleaned up in the source (e.g., ffs_sbget ensures
that memory is always freed if it returns an error).
The original change in r328426 was a bit sparse in its description.
So I am expanding on its description here (thanks cem@ and rgrimes@
for your encouragement for my longer commit messages).
In preparation for adding check hashing to superblocks, r328426 is
a refactoring of the code to get the reading/writing of the superblock
into one place. Unlike the cylinder group reading/writing which
ends up in two places (ffs_getcg/ffs_geom_strategy in the kernel
and cgget/cgput in libufs), I have the core superblock functions
just in the kernel (ffs_sbfetch/ffs_sbput in ffs_subr.c which is
already imported into utilities like fsck_ffs as well as libufs to
implement sbget/sbput). The ffs_sbfetch and ffs_sbput functions
take a function pointer to do the actual I/O for which there are
four variants:
ffs_use_bread / ffs_use_bwrite for the in-kernel filesystem
g_use_g_read_data / g_use_g_write_data for kernel geom clients
ufs_use_sa_read for the standalone code (stand/libsa/ufs.c
but not stand/libsa/ufsread.c which is size constrained)
use_pread / use_pwrite for libufs
Uses of these interfaces are in the UFS filesystem, geoms journal &
label, libsa changes, and libufs. They also permeate out into the
filesystem utilities fsck_ffs, newfs, growfs, clri, dump, quotacheck,
fsirand, fstyp, and quot. Some of these utilities should probably be
converted to directly use libufs (like dumpfs was for example), but
there does not seem to be much win in doing so.
Tested by: Peter Holm (pho@)
ffs_sbget() may return a superblock buffer even if it fails, so the
caller must be prepared to free it in this case. Moreover, when tasting
alternate superblock locations in a loop, ffs_sbget()'s readfunc
callback must free the previously allocated buffer.
Reported and tested by: pho
Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D14390
If the underlying provider's physical path is null, then the gpart device's
physical path will be, too. Otherwise, it will append the partition name,
such as "/p1" or "/s1/a". This will make gpart work better with zfsd(8).
PR: 224965
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D14010
If the underlying provider's physical path is null, then the geli device's
physical path will be, too. Otherwise, it will append "/eli". This will make
geli work better with zfsd(8).
PR: 224962
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D13979
Some GEOM partition tables may be destroyed with incomplete partition
entries. Guard against this with NULL checks.
Reported by: pholm,others
Reviewed by: markj
Tested by: pholm
A race in g_part_wither() can lead to I/O being performed with a freed GEOM
when the device disappears. Close the race as best as we can for now,
following the code patterns from g_part_ctl_destroy() and g_part_ctl_undo().
This also fixes a leak, as g_wither_geom() does not wither providers, it
only orphans them, so the partition entries would never get destroyed in
g_wither_washer().
Note, this is not a complete fix, it can still race with g_part_start(), the
race has merely been narrowed.
Reviewed by: markj
Sponsored by: Dell EMC Isilon
Since synchronization reads are performed by submitting a request to
the external mirror provider, we know that the request returns with an
error only when gmirror was unable to read a copy of the block from any
mirror. Thus, there is no need to retry the request from the
synchronization error handler.
Tested by: pho
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Most consumers of g_metadata_store were passing in partially unallocated
memory, resulting in stack garbage being written to disk labels. Fix them by
zeroing the memory first.
gvirstor repeated the same mistake, but in the kernel.
Also, glabel's label contained a fixed-size string that wasn't
initialized to zero.
PR: 222077
Reported by: Maxim Khitrov <max@mxcrypt.com>
Reviewed by: cem
MFC after: 3 weeks
X-MFC-With: 323314
X-MFC-With: 323338
Differential Revision: https://reviews.freebsd.org/D14164
superblock, and the kernel will fail to link when UFS is not built
in. This commit makes it depend on a small portion of FFS bits and
thereby fixes build for this situation.
This is intended as an interim bandaid, and the actual superblock
reading code should probably be made independent of UFS, so we do
not need to depend on it (see kib@'s comment in the review for
details), and we will revisit this once the superblock check hashes
are all in place.
Differential Revision: https://reviews.freebsd.org/D14092
Specifically reading is done if ffs_sbget() and writing is done
in ffs_sbput(). These functions are exported to libufs via the
sbget() and sbput() functions which then used in the various
filesystem utilities. This work is in preparation for adding
subperblock check hashes.
No functional change intended.
Reviewed by: kib
Uses of mallocarray(9).
The use of mallocarray(9) has rocketed the required swap to build FreeBSD.
This is likely caused by the allocation size attributes which put extra pressure
on the compiler.
Given that most of these checks are superfluous we have to choose better
where to use mallocarray(9). We still have more uses of mallocarray(9) but
hopefully this is enough to bring swap usage to a reasonable level.
Reported by: wosch
PR: 225197
Focus on code where we are doing multiplications within malloc(9). None of
these ire likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.
Differential revision: https://reviews.freebsd.org/D13837
Ths change consists of two parts.
geom_disk: deny opening a disk for writing if it's marked as
write-protected. A new disk(9) flag is added to mark write protected
disks. A possible alternative could be to add another parameter to d_open,
so that the open mode could be passed to it and the disk drivers could
make the decision internally, but the flag required less churn.
scsi_da: add a new phase of disk probing to query the all pages mode
sense page. We can determine if the disk is write protected using bit 7
of the device specific field in the mode parameter header returned by
MODE SENSE.
PR: 224037
Reviewed by: mav
MFC after: 4 weeks
Differential Revision: https://reviews.freebsd.org/D13360
We would previously just free the request BIO, which would either cause
the disk to stay stuck in the SYNCHRONIZING state, or result in
synchronization completing without having copied the block which
returned an error.
With this change, if the disk which returned an error is the only active
disk in the mirror, the synchronizing disk is kicked out. Otherwise, the
read is retried.
Reported and tested by: pho (previous version)
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
g_mirror_regular_request() may free the gmirror consumer for a disk
if that disk is being disconnected, after which we must not dereference
the consumer pointer.
CID: 1384280
X-MFC with: r327496
- BIO_FLUSH requests were dispatched to the disks directly from
g_mirror_start() rather than going through the mirror's I/O request
queue, so they could have been reordered with preceding writes.
Address this by processing such requests from the queue, avoiding
direct dispatch.
- Handling for collisions with synchronization requests was too
fine-grained and could cause reordering of writes. In particular,
BIO_ORDERED was not being honoured. Address this by effectively
freezing the request queue any time a collision with a synchronization
request occurs. The queue is unfrozen once the collision with the
first frozen request is over.
- The above-mentioned collision handling allowed reads to jump ahead
of writes to the same offset. Address this by freezing all request
types when a collision occurs, not just BIO_WRITEs and BIO_DELETEs.
Also add some more fail points for use in testing error handling.
Reviewed by: imp
MFC after: 3 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13559
are places where the "main thread" of the booting kernel (either the
thread which later becomes swapper or the thread which later becomes
init) has to stop and wait for action to take place in another thread
before continuing.
There are currently three such holds:
1. The intr_config_hooks SYSINIT waits for hooks registered via the
config_intrhook_establish function; this allows (typically) devices
which need interrupts enabled to complete their initialization to do
so before root is mounted.
2. The g_waitidle function waits for the GEOM event queue to be empty;
this ensures that all of the disks which have been attached have been
tasted before we attempt to mount root.
3. The vfs_mountroot_wait function (in addition to calling g_waitidle)
waits for holds registered via root_mount_hold; among other things, this
is used by the USB subsystem to ensure that we don't fail to mount root
if it's located on a USB disk which takes a while to probe.
The license merging in r109471 didn't take into account that licensing
could change. Just removing the 3rd clause obviates the copyright
assignment to the NetBSD Foundation.
We do have plenty of files that have two or more licensing as in this
case, so fix this properly by splitting back the licenses as they are
upstream.
Obtained from: NetBSD
Part of this file originated in NetBSD, with the original file
carrying two versions of 4-clause BSD licenses. r109471 attempted to
simplify the situation by putting both licenses together.
Meanwhile, NetBSD dropped Clauses 3 and 4 from their own license, and
eventually NetBSD got permission from the University of Utah to drop the
3rd clause.
Keep the license "simple" by dropping the third clause since both TNF,
Utah/Berkeley and phk agree in principle that it can be dropped.
Obtained from: NetBSD (ccd.c CVS 1.128, 1.138)
This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.
Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385
gmirror does not perform any sorting of I/O requests, so the bioq API
doesn't provide any advantages over plain TAILQs. The API also does not
provide operations needed by an upcoming change.
No functional change intended. The diff shrinks the geom_mirror.ko
text and the gmirror softc slightly.
Tested by: pho (part of a larger patch)
MFC after: 1 week
Sponsored by: Dell EMC Isilon
g_mirror_event_send() acquires the I/O queue lock to deliver a wakeup
to the worker thread, and this is done after enqueuing the event.
So it's sufficient to check the event queue before atomically releasing
the queue lock and going to sleep.
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Otherwise a gmirror that has received a BIO_DELETE request will never be
marked clean (unless sc_writes overflows).
MFC after: 1 week
Sponsored by: Dell EMC Isilon
We periodically record synchronization progress in the metadata
block of the disk being synchronized; this allows an interrupted
synchronization to be resumed. However, the frequency of these
updates heavily pessimized synchronization time on some media. This
change modifies gmirror to update metadata based on a time period,
and adds a sysctl to control that period. The default value results
in a much lower update frequency and increases the completion time
for an interrupted rebuild only marginally.
Reported by: Andre Albsmeier <andre@fbsd.e4m.org>
MFC after: 3 weeks
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.
A negative value can be used to suppress all prints from the gmirror
kernel code, which can be useful when attempting to trigger race
conditions using stress tests.
MFC after: 1 week
produces hex numbers for the dsn. Since that come is from EDK2, change
this for symmetry, by generating the dsn as a hex number.
Noticed by: gpart list | grep efimedia | awk -F: '{print $2;}' | \
sed -e 's/^ *//g;s/,,/,/' | grep MBR | efidp -p | efidp -f
Sponsored by: Netflix
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.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Initially, only tag files that use BSD 4-Clause "Original" license.
RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133
This geom does not immediately detach its consumer relying on the
wither-washer to do that. Since that happens asynchronously we may get
additional spoiling events. So, we need to account for that.
There are multiple options for fixing this issue like detaching
immediately or checking for G_CF_ORPHAN in g_slice_spoiled().
The most reliable and least intrusive fix seems to be setting
geom->softc to NULL on the first call and checking for NULL on
subsequent calls. This is something that the code did before r325227.
Reported by: David Wolfskill <david@catwhisker.org>,
O. Hartmann <o.hartmann@walstatt.org>
Tested by: David Wolfskill <david@catwhisker.org> (earlier version)
Discussed with: mav
MFC after: 1 week
X-MFC with: r325227
