zfs_zevent_console committed multiple printk()s per line without
properly continuing them ‒ a single event could easily be fragmented
across over thirty lines, making it useless for direct application
zfs_zevent_cols exists purely to wrap the output from zfs_zevent_console
The niche this was supposed to fill can be better served by something
akin to the all-syslog ZEDLET
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#7082Closes#11996
When dRAID performs a normal read operation only the data columns
in the raid map are read from disk. This is enough information to
calculate the checksum, verify it, and return the needed data to the
application. It's only in the event of a checksum failure that the
additional parity and any empty columns must be read since they are
required for parity reconstruction.
Reading these additional columns is handled by vdev_raidz_read_all()
which calls vdev_draid_map_alloc_empty() to expand the raid_map_t
and submit IOs for the missing columns. This all works correctly,
but it fails to account for any "short" columns. These are data
columns which are padded with a empty skip sector at the end.
Since that empty sector is not needed for a normal read it's not
read when columns is first read from disk. However, like the parity
and empty columns the skip sector is needed to perform reconstruction.
The fix is to mark any "short" columns as never being read by clearing
the rc_tried flag when expanding the raid_map_t. This will cause
the entire column to re-read from disk in the event of a checksum
failure allowing the self-healing functionality to repair the block.
Note that this only effects the self-healing feature because when
scrubbing a pool the parity, data, and empty columns are all read
initially to verify their contents. Furthermore, only blocks which
contain "short" columns would be effected, and only when the memory
backing the skip sector wasn't already zeroed out.
This change extends the existing redundancy_raidz.ksh test case to
verify self-healing (as well as resilver and scrub). Then applies
the same test case to dRAID with a slightly modified version of
the test script called redundancy_draid.ksh. The unused variable
combrec was also removed from both test cases.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12010
Afterward, git grep ZoL matches:
* README.md: * [ZoL Site](https://zfsonlinux.org)
- Correct
* etc/default/zfs.in:# ZoL userland configuration.
- Changing this would induce a needless upgrade-check,
if the user has modified the configuration;
this can be updated the next time the defaults change
* module/zfs/dmu_send.c: * ZoL < 0.7 does not handle [...]
- Before 0.7 is ZoL, so fair enough
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Issue #11956
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11994
zfs_log_create returns void, so there is no reason to cast its return
value to void at the call site.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11994
Quoting <linux/exportfs.h>:
> encode_fh() should return the fileid_type on success and on error
> returns 255 (if the space needed to encode fh is greater than
> @max_len*4 bytes). On error @max_len contains the minimum size (in 4
> byte unit) needed to encode the file handle.
ZFS was not setting max_len in the case where the handle was too
small. As a result of this, the `t_name_to_handle_at.c' example in
name_to_handle_at(2) did not work on ZFS.
zfsctl_fid() will itself set max_len if called with a fid that is too
small, so if we give zfs_fid() that behavior as well, the fix is quite
easy: if the handle is too small, just use a zero-size fid instead of
the handle.
Tested by running t_name_to_handle_at on a normal file, a directory, a
.zfs directory, and a snapshot.
Thanks-to: Puck Meerburg <puck@puckipedia.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Closes#11995
Previous code tried to keep prefetch streams while moving dnode. But
it was at least not updating per-stream zs_fetchback pointers, causing
use-after-free on next access. Instead of that I see much easier and
cleaner to just drop old prefetch state and start new from scratch.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#11936Closes#11998
zp->z_lock is used in shared code for protecting projid and scantime.
We don't exercise these paths much if at all on FreeBSD, so have been
lucky enough not to have issues with the uninitialized locks so far.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#12003
IS_XATTRDIR is never used.
v_count is only used in two places, one immediately followed by the
use of the real name, v_usecount.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#11973
This ensures that we don't accumulate checksum errors against offline or
unavailable devices but, more importantly, means that we don't
needlessly create DTL entries for offline devices that are already
up-to-date.
Consider a 3-way mirror, with disk A always online (and so always with
an empty DTL) and B and C only occasionally online. When A & B resilver
with C offline, B's DTL will effectively be appended to C's due to these
spurious ZIOs even as the resilver empties B's DTL:
* These ZIOs land in vdev_mirror_scrub_done() and flag an error
* That flagged error causes vdev_mirror_io_done() to see
unexpected_errors, so it issues a ZIO_TYPE_WRITE repair ZIO, which
inherits ZIO_FLAG_SCAN_THREAD because zio_vdev_child_io() includes
that flag in ZIO_VDEV_CHILD_FLAGS.
* That ZIO fails, too, and eventually zio_done() gets its hands on it
and calls vdev_stat_update().
* vdev_stat_update() sees the error and this zio...
* is not speculative,
* is not due to EIO (but rather ENXIO, since the device is closed)
* has an ->io_vd != NULL (specifically, the offline leaf device)
* is a write
* is for a txg != 0 (but rather the read block's physical birth txg)
* has ZIO_FLAG_SCAN_THREAD asserted
* So: vdev_stat_update() calls vdev_dtl_dirty() on the offline vdev.
Then, when A & C resilver with B offline, that story gets replayed and
C's DTL will be appended to B's.
In fact, one does not need this permanently-broken-mirror scenario to
induce badness: breaking a mirror with no DTLs and then scrubbing will
create DTLs for all offline devices. These DTLs will persist until the
entire mirror is reassembled for the duration of the *resilver*, which,
incidentally, will not consider the devices with good data to be sources
of good data in the case of a read failure.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Nathaniel Wesley Filardo <nwfilardo@gmail.com>
Closes#11930
This obeys the change in freebsd/freebsd-src@bce7ee9d4
External-issue: https://reviews.freebsd.org/D26980
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes#11947
Introduce a specific valid function for avx512f+avx512bw (instead
of checking only for avx512f).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam Moss <c@yotes.com>
Signed-off-by: Romain Dolbeau <romain@dolbeau.org>
Closes#11937Closes#11938
Objtool requires the use of a DRAP register while aligning the
stack. Since a DRAP register is a gcc concept and we are
notoriously low on registers in the crypto code, it's not worth
the effort to mimic gcc generated stack realignment.
We simply silence the warning by adding the offending object files
to OBJECT_FILES_NON_STANDARD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#6950Closes#11914
This deduplicates 2 sets of caches which use the same allocation size.
Memory savings fluctuate a lot, one sample result is FreeBSD running
"make buildworld" saving ~180MB RAM in reduced page count associated
with zio caches.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes#11877
Fix NULL pointer dereference when reporting
checksum error for gang block in zio_done.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes#11872Closes#11896
This fixes /proc/sys/kernel/spl/hostid on kernels with mainline commit
32927393dc1ccd60fb2bdc05b9e8e88753761469 ("sysctl: pass kernel pointers
to ->proc_handler") ‒ 5.7-rc1 and up
The access_ok() check in copy_to_user() in proc_copyout_string() would
always fail, so all userspace reads and writes would fail with EINVAL
proc_dostring() strips only the final new-line,
but simple_strtoul() doesn't actually need a back-trimmed string ‒
writing "012345678 \n" is still allowed, as is "012345678zupsko", &c.
This alters what happens when an invalid value is written ‒
previously it'd get set to what-ever simple_strtoul() returned
(probably 0, thereby resetting it to default), now it does nothing
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11878Closes#11879
Traversal code, traverse_visitbp() does visit blocks recursively.
Indirect (Non L0) Block of size 128k could contain, 1024 block pointers
of 128 bytes. In case of full traverse OR incremental traverse, where
all blocks were modified, it could traverse large number of blocks
pointed by indirect. Traversal code does issue prefetch of blocks
traversed below indirect. This could result into large number of
async reads queued on vdev queue. So, account for prefetch issued for
blocks pointed by indirect and limit max prefetch in one go.
Module Param:
zfs_traverse_indirect_prefetch_limit: Limit of prefetch while traversing
an indirect block.
Local counters:
prefetched: Local counter to account for number prefetch done.
pidx: Index for which next prefetch to be issued.
ptidx: Index at which next prefetch to be triggered.
Keep "ptidx" somewhere in the middle of blocks prefetched, so that
blocks prefetch read gets the enough time window before their demand
read is issued.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes#11802Closes#11803
This change adds SIGSTOP and SIGTSTP handling to the issig function;
this mirrors its behavior on Solaris. This way, long running kernel
tasks can be stopped with the appropriate signals. Note that doing
so with ctrl-z on the command line doesn't return control of the tty
to the shell, because tty handling is done separately from stopping
the process. That can be future work, if people feel that it is a
necessary addition.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Issue #810
Issue #10843Closes#11801
It happens to trip over an assert but does not matter for correctness at
this time. Done for future proofing.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes#11884
It's been observed in the CI that the required 25% of obsolete bytes
in the mapping can be to high a threshold for this test resulting in
condensing never being triggered and a test failure. To prevent these
failures make the existing zfs_condense_indirect_obsolete_pct tuning
available so the obsolete percentage can be reduced from 25% to 5%
during this test.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11869
SMACK needs to have the ZFS dentry security field setup before
SMACK's d_instantiate() hook is called as it requires functioning
'__vfs_getxattr()' calls to properly set the labels.
Fxes:
1) file instantiation properly setting the object label to the
subject's label
2) proper file labeling in a transmutable directory
Functions Updated:
1) zpl_create()
2) zpl_mknod()
3) zpl_mkdir()
4) zpl_symlink()
External-issue: https://github.com/cschaufler/smack-next/issues/1
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: TerraTech <TerraTech@users.noreply.github.com>
Closes#11646Closes#11839
When a rebuild completes it will automatically schedule a follow up
scrub to verify all of the block checksums. Before setting up the
scrub execute the counterpart dsl_scan_setup_check() function to
confirm the scrub can be started. Prior to this change we'd only
check vdev_rebuild_active() which isn't as comprehensive, and using
the check function keeps all of this logic in one place.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11849
Just as delay zevents can flood the zevent pipe when a vdev becomes
unresponsive, so do the deadman zevents.
Ratelimit deadman zevents according to the same tunable as for delay
zevents.
Enable deadman tests on FreeBSD and add a test for deadman event
ratelimiting.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11786
Correct an assortment of typos throughout the code base.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#11774
Nothing bad happens if a prefix of your pool name matches a disk name.
This is a bit of a silly restriction at this point.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes#11781Closes#11813
The lower bound for this scaling to too low and the upper bound is too
high. Use a fixed default length of 512 instead, which is a reasonable
value on any system.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11822
ratelimit_dropped isn't protected by a lock and is expected to
be updated atomically.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11822
For gang blocks, `DVA_GET_ASIZE()` is the total space allocated for the
gang DVA including its children BP's. The space allocated at each DVA's
vdev/offset is `vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE)`.
This commit makes this relationship more clear by using a helper
function, `vdev_gang_header_asize()`, for the space allocated at the
gang block's vdev/offset.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11744
Other (all?) Linux filesystems seem to return -EPERM instead of -EACCESS
when trying to set FS_APPEND_FL or FS_IMMUTABLE_FL without the
CAP_LINUX_IMMUTABLE capability. This was detected by generic/545 test
in the fstest suite.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Luis Henriques <henrix@camandro.org>
Closes#11791
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#11775
To make better predictions on parallel workloads dmu_zfetch() should
be called as early as possible to reduce possible request reordering.
In particular, it should be called before dmu_buf_hold_array_by_dnode()
calls dbuf_hold(), which may sleep waiting for indirect blocks, waking
up multiple threads same time on completion, that can significantly
reorder the requests, making the stream look like random. But we
should not issue prefetch requests before the on-demand ones, since
they may get to the disks first despite the I/O scheduler, increasing
on-demand request latency.
This patch splits dmu_zfetch() into two functions: dmu_zfetch_prepare()
and dmu_zfetch_run(). The first can be executed as early as needed.
It only updates statistics and makes predictions without issuing any
I/Os. The I/O issuance is handled by dmu_zfetch_run(), which can be
called later when all on-demand I/Os are already issued. It even
tracks the activity of other concurrent threads, issuing the prefetch
only when _all_ on-demand requests are issued.
For many years it was a big problem for storage servers, handling
deeper request queues from their clients, having to either serialize
consequential reads to make ZFS prefetcher usable, or execute the
incoming requests as-is and get almost no prefetch from ZFS, relying
only on deep enough prefetch by the clients. Benefits of those ways
varied, but neither was perfect. With this patch deeper queue
sequential read benchmarks with CrystalDiskMark from Windows via
iSCSI to FreeBSD target show me much better throughput with almost
100% prefetcher hit rate, comparing to almost zero before.
While there, I also removed per-stream zs_lock as useless, completely
covered by parent zf_lock. Also I reused zs_blocks refcount to track
zf_stream linkage of the stream, since I believe previous zs_fetch ==
NULL check in dmu_zfetch_stream_done() was racy.
Delete prefetch streams when they reach ends of files. It saves up
to 1KB of RAM per file, plus reduces searches through the stream list.
Block data prefetch (speculation and indirect block prefetch is still
done since they are cheaper) if all dbufs of the stream are already
in DMU cache. First cache miss immediately fires all the prefetch
that would be done for the stream by that time. It saves some CPU
time if same files within DMU cache capacity are read over and over.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam Moss <c@yotes.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#11652
If TX_WRITE is create on a file, and the file is later deleted and a new
directory is created on the same object id, it is possible that when
zil_commit happens, zfs_get_data will be called on the new directory.
This may result in panic as it tries to do range lock.
This patch fixes this issue by record the generation number during
zfs_log_write, so zfs_get_data can check if the object is valid.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes#10593Closes#11682
Commit 235a85657 introduced a regression in evaluation of POSIX modes
that require group DENY entries in the internal ZFS ACL. An example
of such a POSX mode is 007. When write_implies_delete_child is set,
then ACE_WRITE_DATA is added to `wanted_dirperms` in prior to calling
zfs_zaccess_common(). This occurs is zfs_zaccess_delete().
Unfortunately, when zfs_zaccess_aces_check hits this particular DENY
ACE, zfs_groupmember() is checked to determine whether access should be
denied, and since zfs_groupmember() always returns B_TRUE on Linux and
so this check is failed, resulting ultimately in EPERM being returned.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
Closes#11760
The FreeBSD boot loader relies on the bootfs property and is capable
of booting from removed (indirect) vdevs.
Reviewed-by Eric van Gyzen
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes#11763
It used to be required to pass a enum km_type to kmap_atomic() and
kunmap_atomic(), however this is no longer necessary and the wrappers
zfs_k(un)map_atomic removed these. This is confusing in the ABD code as
the struct abd_iter member iter_km no longer exists and the wrapper
macros simply compile them out.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam Moss <c@yotes.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11768
= Motivation
We've noticed several zloop crashes within Delphix generated
due to the following sequence of events:
- A device gets expanded and new metaslabas are allocated for
it. These metaslabs go through `metaslab_init()` but haven't
gone through `metaslab_sync_done()` yet. This meas that the
only range tree that's actually set is the `ms_allocatable`.
All the others are NULL.
- A vdev_initialization is issues and `vdev_initialize_thread`
starts processing one of these new metaslabs of the expanded
vdev.
- As part of `vdev_initialize_calculate_progress()` we call
into `metaslab_load()` and `metaslab_load_impl()` which
in turn tries to dereference the metaslabs trees that
are still NULL and therefore we crash.
The same failure can come up from the `vdev_trim` code paths.
= This Patch
We considered the following solutions to deal with this issue:
[A] Add logic to `vdev_initialize/trim` to skip those new
metaslabs. We decided against this as it would be good
to avoid exposing this lower-level detail to higer-level
operations.
[B] Have `metaslab_load_impl()` return early for new metaslabs
and thus never touch those range_trees that are NULL at
that time. This seemed more of a work-around for the bug
and not a clear-cut solution.
[C] Refactor our logic so all metaslabs have their range_trees
created at the time of their creatin in `metaslab_init()`.
In this patch we decided to go with [C] because:
(1) It doesn't expose more metaslab details to higher level
operations such as vdev initialize and trim.
(2) The current behavior of creating the range trees lazily
in `metaslab_sync_done()` is unnecessarily complicated.
(3) Always initializing the metaslab range_trees makes other
parts of the codebase cleaner. For example, we used to
use `ms_freed` as the reference value for knowing whether
all the range_trees have been initialized. Now we no
longer need to do that check in most places (and in the
few that we do we use the `ms_new` boolean field now
which is more readable).
= Side Changes
Probably due to a mismerge we set `ms_loaded` to `B_TRUE` twice
in `metasloab_load_impl()`. In this patch we remove the extraneous
assignment.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#11737
The BIO_MAX_PAGES macro is being retired in favor of a bio_max_segs()
function that implements the typical MIN(x,y) logic used throughout the
kernel for bounding the allocation, and also the new implementation is
intended to be signed-safe (which the former was not).
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11765
In Linux 5.12, the filesystem API was modified to support ipmapped
mounts by adding a "struct user_namespace *" parameter to a number
functions and VFS handlers. This change adds the needed autoconf
macros to detect the new interfaces and updates the code appropriately.
This change does not add support for idmapped mounts, instead it
preserves the existing behavior by passing the initial user namespace
where needed. A subsequent commit will be required to add support
for idmapped mounted.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11712
The RAIDZ and DRAID code is responsible for reporting checksum errors on
their child vdevs. Checksum errors represent events where a disk
returned data or parity that should have been correct, but was not. In
other words, these are instances of silent data corruption. The
checksum errors show up in the vdev stats (and thus `zpool status`'s
CKSUM column), and in the event log (`zpool events`).
Note, this is in contrast with the more common "noisy" errors where a
disk goes offline, in which case ZFS knows that the disk is bad and
doesn't try to read it, or the device returns an error on the requested
read or write operation.
RAIDZ/DRAID generate checksum errors via three code paths:
1. When RAIDZ/DRAID reconstructs a damaged block, checksum errors are
reported on any children whose data was not used during the
reconstruction. This is handled in `raidz_reconstruct()`. This is the
most common type of RAIDZ/DRAID checksum error.
2. When RAIDZ/DRAID is not able to reconstruct a damaged block, that
means that the data has been lost. The zio fails and an error is
returned to the consumer (e.g. the read(2) system call). This would
happen if, for example, three different disks in a RAIDZ2 group are
silently damaged. Since the damage is silent, it isn't possible to know
which three disks are damaged, so a checksum error is reported against
every child that returned data or parity for this read. (For DRAID,
typically only one "group" of children is involved in each io.) This
case is handled in `vdev_raidz_cksum_finish()`. This is the next most
common type of RAIDZ/DRAID checksum error.
3. If RAIDZ/DRAID is not able to reconstruct a damaged block (like in
case 2), but there happens to be additional copies of this block due to
"ditto blocks" (i.e. multiple DVA's in this blkptr_t), and one of those
copies is good, then RAIDZ/DRAID compares each sector of the data or
parity that it retrieved with the good data from the other DVA, and if
they differ then it reports a checksum error on this child. This
differs from case 2 in that the checksum error is reported on only the
subset of children that actually have bad data or parity. This case
happens very rarely, since normally only metadata has ditto blocks. If
the silent damage is extensive, there will be many instances of case 2,
and the pool will likely be unrecoverable.
The code for handling case 3 is considerably more complicated than the
other cases, for two reasons:
1. It needs to run after the main raidz read logic has completed. The
data RAIDZ read needs to be preserved until after the alternate DVA has
been read, which necessitates refcounts and callbacks managed by the
non-raidz-specific zio layer.
2. It's nontrivial to map the sections of data read by RAIDZ to the
correct data. For example, the correct data does not include the parity
information, so the parity must be recalculated based on the correct
data, and then compared to the parity that was read from the RAIDZ
children.
Due to the complexity of case 3, the rareness of hitting it, and the
minimal benefit it provides above case 2, this commit removes the code
for case 3. These types of errors will now be handled the same as case
2, i.e. the checksum error will be reported against all children that
returned data or parity.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11735
Avoids tripping on asserts when doing pool recovery.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes#11739
The `rr_code` field in `raidz_row_t` is unused.
This commit removes the field, as well as the code that's used to set
it.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11736
Don't handle (incorrectly) kmem_zalloc() failure. With KM_SLEEP,
will never return NULL.
Free the data allocated for non-virtual kstats when deleting the object.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11767
zhold() wraps igrab() on Linux, and igrab() may fail when the inode
is in the process of being deleted. This means zhold() must only be
called when a reference exists and therefore it cannot be deleted.
This is the case for all existing consumers so add a VERIFY and a
comment explaining this requirement.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Adam Moss <c@yotes.com>
Closes#11704
