On Illumos callers of cv_timedwait and cv_timedwait_hires
can't distinguish between whether or not the cv was signaled
or the call timed out. Illumos handles this (for some definition
of handles) by calling cv_signal in the return path if we were
signaled but the return value indicates instead that we timed
out. This would make sense if it were possible to query the the
cv for its net signal disposition. However, this isn't possible
and, in spite of the fact that there are places in the code that
clearly take a different and incompatible path if a timeout value
is indicated, this distinction appears to be rather subtle to most
developers. This problem is further compounded by the fact that on
Linux, calling cv_signal in the return path wouldn't even do the
right thing unless there are other waiters.
Since it is possible for the caller to independently determine how
much time is remaining but it is not possible to query if the cv
was in fact signaled, prioritizing signalling over timeout seems
like a cleaner solution. In addition, judging from usage patterns
within the code itself, it is also less error prone.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10471
Apparently missed in the initial port integration was
the need to reap the abd_chunk_cache on FreeBSD. This
change addresses that oversight.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10474
As it uses kmem_strdup() and kmem_strfree() which both rely on
strlen() being the same, but saved_poolname can be truncated causing:
SPL: kernel memory allocator:
buffer freed to wrong cache
SPL: buffer was allocated from kmem_alloc_16,
SPL: caller attempting free to kmem_alloc_8.
SPL: buffer=0xffffff90acc66a38 bufctl=0x0 cache: kmem_alloc_8
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10469
For at least 15 years since OpenSolaris arc_c was set by default to
arc_c_max, later decreased under memory pressure. I've noticed that
if arc_c was set high enough to cause memory pressure as considered
by ZFS, setting of arc_no_grow to TRUE in arc_reap_cb_check() makes
no effect until both arc_kmem_reap_soon() and delay(reap_retry_ms)
return. All that time ZFS can continue increasing its effective ARC
size, causing more memory pressure, potentially up to the point when
OS low memory handler activates and reduces arc_c, requesting fast
reclamation of just allocated memory.
The problem seems to be more serious on FreeBSD and I guess Linux,
since neither of them implement/use asynchronous kmem reclamation,
so arc_kmem_reap_soon() can take more time. On older FreeBSD 11 not
supporting multiple memory domains system with lots of RAM can get
completely unresponsive for minutes due to heavy lock congestion
between ARC reclamation and page daemon kmem reclamation threads.
With this change to more conservative arc_c value ARC stops growing
just it time and does not need later reclamation.
Also while there, since now growing arc_c is a more often situation,
use aggsum_upper_bound() instead of aggsum_compare() in arc_adapt()
to reduce lock congestion. It is also getting in sync with code in
arc_get_data_impl().
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#10437
The macOS uio struct is opaque and the API must be used, this
makes the smallest changes to the code for all platforms.
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10412
On macOS clock_t is unsigned, so when cv_timedwait_hires() returns -1
we loop forever. The conditional was tweaked to ignore signedness.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10445
The linux module can be built either as an external module, or compiled
into the kernel, using copy-builtin. The source and build directories
are slightly different between the two cases, and currently, compiling
into the kernel still refers to some files from the configured ZFS
source tree, instead of the copies inside the kernel source tree. There
is also duplication between copy-builtin, which creates a Kbuild file to
build ZFS inside the kernel tree, and the top-level module/Makefile.in.
Fix this by moving the list of modules and the CFLAGS settings into a
new module/Kbuild.in, which will be used by the kernel kbuild
infrastructure, and using KBUILD_EXTMOD to distinguish the two cases
within the Makefiles, in order to choose appropriate include
directories etc.
Module CFLAGS setting is simplified by using subdir-ccflags-y (available
since 2.6.30) to set them in the top-level Kbuild instead of each
individual module. The disabling of -Wunused-but-set-variable is removed
from the lua and zfs modules. The variable that the Makefile uses is
actually not defined, so this has no effect; and the warning has long
been disabled by the kernel Makefile itself.
The target_cpu definition in module/{zfs,zcommon} is removed as it was
replaced by use of CONFIG_SPARC64 in
commit 70835c5b75 ("Unify target_cpu handling")
os/linux/{spl,zfs} are removed from obj-m, as they are not modules in
themselves, but are included by the Makefile in the spl and zfs module
directories. The vestigial Makefiles in os and os/linux are removed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes#10379Closes#10421
Correct various typos in the comments and tests.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#10423
Background:
By increasing the recordsize property above the default of 128KB, a
filesystem may have "large" blocks. By default, a send stream of such a
filesystem does not contain large WRITE records, instead it decreases
objects' block sizes to 128KB and splits the large blocks into 128KB
blocks, allowing the large-block filesystem to be received by a system
that does not support the `large_blocks` feature. A send stream
generated by `zfs send -L` (or `--large-block`) preserves the large
block size on the receiving system, by using large WRITE records.
When receiving an incremental send stream for a filesystem with large
blocks, if the send stream's -L flag was toggled, a bug is encountered
in which the file's contents are incorrectly zeroed out. The contents
of any blocks that were not modified by this send stream will be lost.
"Toggled" means that the previous send used `-L`, but this incremental
does not use `-L` (-L to no-L); or that the previous send did not use
`-L`, but this incremental does use `-L` (no-L to -L).
Changes:
This commit addresses the problem with several changes to the semantics
of zfs send/receive:
1. "-L to no-L" incrementals are rejected. If the previous send used
`-L`, but this incremental does not use `-L`, the `zfs receive` will
fail with this error message:
incremental send stream requires -L (--large-block), to match
previous receive.
2. "no-L to -L" incrementals are handled correctly, preserving the
smaller (128KB) block size of any already-received files that used large
blocks on the sending system but were split by `zfs send` without the
`-L` flag.
3. A new send stream format flag is added, `SWITCH_TO_LARGE_BLOCKS`.
This feature indicates that we can correctly handle "no-L to -L"
incrementals. This flag is currently not set on any send streams. In
the future, we intend for incremental send streams of snapshots that
have large blocks to use `-L` by default, and these streams will also
have the `SWITCH_TO_LARGE_BLOCKS` feature set. This ensures that streams
from the default use of `zfs send` won't encounter the bug mentioned
above, because they can't be received by software with the bug.
Implementation notes:
To facilitate accessing the ZPL's generation number,
`zfs_space_delta_cb()` has been renamed to `zpl_get_file_info()` and
restructured to fill in a struct with ZPL-specific info including owner
and generation.
In the "no-L to -L" case, if this is a compressed send stream (from
`zfs send -cL`), large WRITE records that are being written to small
(128KB) blocksize files need to be decompressed so that they can be
written split up into multiple blocks. The zio pipeline will recompress
each smaller block individually.
A new test case, `send-L_toggle`, is added, which tests the "no-L to -L"
case and verifies that we get an error for the "-L to no-L" case.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#6224Closes#10383
The l2arc_evict() function is responsible for evicting buffers which
reference the next bytes of the L2ARC device to be overwritten. Teach
this function to additionally TRIM that vdev space before it is
overwritten if the device has been filled with data. This is done by
vdev_trim_simple() which trims by issuing a new type of TRIM,
TRIM_TYPE_SIMPLE.
We also implement a "Trim Ahead" feature. It is a zfs module parameter,
expressed in % of the current write size. This trims ahead of the
current write size. A minimum of 64MB will be trimmed. The default is 0
which disables TRIM on L2ARC as it can put significant stress to
underlying storage devices. To enable TRIM on L2ARC we set
l2arc_trim_ahead > 0.
We also implement TRIM of the whole cache device upon addition to a
pool, pool creation or when the header of the device is invalid upon
importing a pool or onlining a cache device. This is dependent on
l2arc_trim_ahead > 0. TRIM of the whole device is done with
TRIM_TYPE_MANUAL so that its status can be monitored by zpool status -t.
We save the TRIM state for the whole device and the time of completion
on-disk in the header, and restore these upon L2ARC rebuild so that
zpool status -t can correctly report them. Whole device TRIM is done
asynchronously so that the user can export of the pool or remove the
cache device while it is trimming (ie if it is too slow).
We do not TRIM the whole device if persistent L2ARC has been disabled by
l2arc_rebuild_enabled = 0 because we may not want to lose all cached
buffers (eg we may want to import the pool with
l2arc_rebuild_enabled = 0 only once because of memory pressure). If
persistent L2ARC has been disabled by setting the module parameter
l2arc_rebuild_blocks_min_l2size to a value greater than the size of the
cache device then the whole device is trimmed upon creation or import of
a pool if l2arc_trim_ahead > 0.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam D. Moss <c@yotes.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#9713Closes#9789Closes#10224
In Illumos it is possible to call ioctl functions from within the
kernel by passing the FKIOCTL flag. Neither FreeBSD nor Linux support
that, but it doesn't hurt to keep it around, as all the code is there.
Before this commit it was a dead code and zc_iflags was always zero.
Restore this functionality by allowing to pass a flag to the
zfsdev_ioctl_common() function.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes#10417
The strcpy() and sprintf() functions are deprecated on some platforms.
Care is needed to ensure correct size is used. If some platforms
miss snprintf, we can add a #define to sprintf, likewise strlcpy().
The biggest change is adding a size parameter to zfs_id_to_fuidstr().
The various *_impl_get() functions are only used on linux and have
not yet been updated.
Reviewed by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10400
It was possible to cause a kernel panic in the send code by
initializing an already-initialized mutex, if a record was created
with type DATA, destroyed with a different type (bypassing the
mutex_destroy call) and then re-allocated as a DATA record again.
We tweak the logic to not change the type of a record once it has
been created, avoiding the issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#10374
FreeBSD needs arc_adjust_zthr to run periodically for kstats to be
updated. A comment in the code suggests this may have been the
original intent in illumos as well:
c946d5a913/module/zfs/arc.c (L4697-L4700)
Create the thread with a 1 second timer.
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10371
The dsl_destroy_snapshots_nvl() function has an early error out,
and temporary nvlists were not freed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#10366
Adding the gang ABD type, which allows for linear and scatter ABDs to
be chained together into a single ABD.
This can be used to avoid doing memory copies to/from ABDs. An example
of this can be found in vdev_queue.c in the vdev_queue_aggregate()
function.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian <bwa@clemson.edu>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#10069
Due to hotplug support or BIOS bugs sometimes max_ncpus can be
an absurdly high value. I have a system with 32 cores/threads
but reports max_ncpus == 440. This many threads potentially
cripples the system during arc_prune floods for example.
boot_ncpus is the number of working CPUs when called so use
that instead.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes#10282
If `receive_writer_thread()` gets an error from `receive_process_record()`,
it should be saved in `rwa->err` so that we will stop processing records,
and the main thread will notice that the receive has failed.
When an error is first encountered, this happens correctly. However, if
there are more records to dequeue, the next time through the loop we
will reset `rwa->err` to zero, allowing us to try to process the
following record (2 after the failed record). Depending on what types
of records remain, we may incorrectly complete the receive
"successfully", but without actually having processed all the records.
The fix is to only set `rwa->err` if we got a *non-zero* error.
This bug was introduced by #10099 "Improve zfs receive performance by
batching writes".
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10320
Commit fc551d7 introduced the wrappers abd_enter_critical() and
abd_exit_critical() to mark critical sections. On Linux these are
implemented with the local_irq_save() and local_irq_restore() macros
which set the 'flags' argument when saving. By wrapping them with
a function the local variable is no longer set by the macro and is
no longer properly restored.
Convert abd_enter_critical() and abd_exit_critical() to macros to
resolve this issue and ensure the flags are properly restored.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#10332
The member drc_err of dmu_recv_cookie_t is used only locally in
receive_read, so we can replace it with a local variable.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10319
When a resilver finishes, vdev_dtl_reassess is called to hopefully
excise DTL_MISSING (amongst other things). If there are errors during
the resilver, they are tracked in DTL_SCRUB, as spelled out in the
block comment in vdev.c. DTL_SCRUB is in-core only, so it can only
be used if the pool was online for the whole resilver. This state is
tracked with the spa_scrub_started flag, which only gets set when
the scan is initialized. Unfortunately, this flag gets cleared right
before vdev_dtl_reassess gets called, so if there are any errors
during the scan, DTL_MISSING will never get excised and the resilver
will just continually restart. This fix simply moves clearing that
flag until after the call to vdev_dtl_reasses.
In addition, if a pool is imported and already has scn_errors > 0,
this change will restart the resilver immediately instead of doing
the rest of the scan and then restarting it from the beginning. On
the other hand, if scn_errors == 0 at import, then no errors have
been encountered so far, so the spa_scrub_started flag can be safely
set.
A test has been added to verify that resilver does not restart when
relevant DTL's are available.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: John Poduska <jpoduska@datto.com>
Closes#10291
Reorganizing ABD code base so OS-independent ABD code has been placed
into a common abd.c file. OS-dependent ABD code has been left in each
OS's ABD source files, and these source files have been renamed to
abd_os.
The OS-independent ABD code is now under:
module/zfs/abd.c
With the OS-dependent code in:
module/os/linux/zfs/abd_os.c
module/os/freebsd/zfs/abd_os.c
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#10293
Functional changes:
We implement refcounts of log blocks and their aligned size on the
cache device along with two corresponding arcstats. The refcounts are
reflected in the header of the device and provide valuable information
as to whether log blocks are accounted for correctly. These are
dynamically adjusted as log blocks are committed/evicted. zdb also uses
this information in the device header and compares it to the
corresponding values as reported by dump_l2arc_log_blocks() which
emulates l2arc_rebuild(). If the refcounts saved in the device header
report higher values, zdb exits with an error. For this feature to work
correctly there should be no active writes on the device. This is also
employed in the tests of persistent L2ARC. We extend the structure of
the cache device header by adding the two new variables mirroring the
refcounts after the existing variables to preserve backward
compatibility in terms of persistent L2ARC.
1) a new arcstat "l2_log_blk_asize" and refcount "l2ad_lb_asize" which
reflect the total aligned size of log blocks on the device. This is
also reflected in the header of the cache device as "dh_lb_asize".
2) a new arcstat "l2arc_log_blk_count" and refcount "l2ad_lb_count"
which reflect the total number of L2ARC log blocks present on cache
devices. It is also reflected in the header of the cache device as
"dh_lb_count".
In l2arc_rebuild_vdev() if the amount of committed log entries in a log
block is 0 and the device header is valid we update the device header.
This will facilitate trimming of the whole device in this case when
TRIM for L2ARC is implemented.
Improve loop protection in l2arc_rebuild() by using the starting offset
of the payload of each log block instead of the starting offset of the
log block.
If the zio in l2arc_write_buffers() fails, restore the lbps array in the
header of the device to its previous state in l2arc_write_done().
If l2arc_rebuild() ends the rebuild process without restoring any L2ARC
log blocks in ARC and without any other error, this means that the lbps
array in the header is pointing to non-existent or invalid log blocks.
Reset the device header in this case.
In l2arc_rebuild() change the zfs_dbgmsg messages to
spa_history_log_internal() making them user visible with zpool history
command.
Non-functional changes:
Make the first test in persistent L2ARC use `zdb -lll` to increase
coverage in `zdb.c`.
Rename psize with asize when referring to log blocks, since
L2ARC_SET_PSIZE stores the vdev aligned size for log blocks. Also
rename dh_log_blk_entries to dh_log_entries to make it clear that
it is a mirror of l2ad_log_entries. Added comments for both changes.
Fix inaccurate comments for example in l2arc_log_blk_restore().
Add asserts at the end in l2arc_evict() and l2arc_write_buffers().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10228
Modern bootloaders leverage data stored in the root filesystem to
enable some of their powerful features. GRUB specifically has a grubenv
file which can store large amounts of configuration data that can be
read and written at boot time and during normal operation. This allows
sysadmins to configure useful features like automated failover after
failed boot attempts. Unfortunately, due to the Copy-on-Write nature
of ZFS, the standard behavior of these tools cannot handle writing to
ZFS files safely at boot time. We need an alternative way to store
data that allows the bootloader to make changes to the data.
This work is very similar to work that was done on Illumos to enable
similar functionality in the FreeBSD bootloader. This patch is different
in that the data being stored is a raw grubenv file; this file can store
arbitrary variables and values, and the scripting provided by grub is
powerful enough that special structures are not required to implement
advanced behavior.
We repurpose the second padding area in each label to store the grubenv
file, protected by an embedded checksum. We add two ioctls to get and
set this data, and libzfs_core and libzfs functions to access them more
easily. There are no direct command line interfaces to these functions;
these will be added directly to the bootloader utilities.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#10009
When a top-level vdev is removed from a pool it is converted to an
indirect vdev. Until now splitting such mirrored pools was not possible
with zpool split. This patch enables handling of indirect vdevs and
splitting of those pools with zpool split.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10283
This patch corrects a bug introduced in 61152d1069. When
resuming a raw base receive, the dmu_recv code always sets
drc->drc_fromsnapobj to the object ID of the previous
snapshot. For incrementals, this is correct, but for base
sends, this should be left at 0. The presence of this ID
eventually allows a check to run which determines whether
or not the incoming stream and the previous snapshot have
matching IVset guids. This check fails becuase it is not
meant to run when there is no previous snapshot. When it
does fail, the user receives an error stating that the
incoming stream has the problem outlined in errata 4.
This patch corrects this issue by simply ensuring
drc->drc_fromsnapobj is left as 0 for base receives.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#10234Closes#10239
Deduplicated send streams (i.e. `zfs send -D` and `zfs receive` of such
streams) are deprecated. Deduplicated send streams can be received by
first converting them to non-deduplicated with the `zstream redup`
command.
This commit removes the code for sending and receiving deduplicated send
streams. `zfs send -D` will now print a warning, ignore the `-D` flag,
and generate a regular (non-deduplicated) send stream. `zfs receive` of
a deduplicated send stream will print an error message and fail.
The resulting code simplification (especially in the kernel's support
for receiving dedup streams) should help enable future performance
enhancements.
Several new tests are added which leverage `zstream redup`.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #7887
Issue #10117
Issue #10156Closes#10212
Each metaslab group (of which there is one per top-level vdev) has
several (4, by default) "metaslab group allocators". Each "allocator"
has its own metaslab that it prefers to allocate from (the "primary"
allocator), and each can perform allocations concurrently with the other
allocators. In addition to the primary metaslab, there are several
other fields that need to be tracked separately for each allocator.
These are currently stored as several arrays in the metaslab_group_t,
each array indexed by allocator number.
This change organizes all the metaslab-group-allocator-specific fields
into a new struct, metaslab_group_allocator_t. The metaslab_group_t now
needs only one array indexed by the allocator number - which contains
the metaslab_group_allocator_t's.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10213
The progress of a send is supposed to be reported by `zfs send -v`, but
it is not. This works by creating a new user thread (with
pthread_create()) which does ZFS_IOC_SEND_PROGRESS ioctls to check how
much progress has been made. This IOCTL finds the specified send (since
there may be multiple concurrent sends in the system). The IOCTL also
checks that the specified send was started by the current process.
On Linux, different threads of the same process are represented as
different `struct task_struct`s (and, confusingly, have different
PID's). To check if if two threads are in the same process, we need to
check if they have the same `struct task_struct:group_leader`.
We used to to this correctly, but it was inadvertently changed by
30af21b025 (Redacted Send) to simply check if the current
`struct task_struct` is the one that started the send.
This commit changes the code back to checking if the send was started by
a `struct task_struct` with the same `group_leader` as the calling
thread.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Chris Wedgwood <cw@f00f.org>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10215Closes#10216
Minor fixes on persistent L2ARC improving code readability and fixing
a typo in zdb.c when byte-swapping a log block. It also improves the
pesist_l2arc_007_pos.ksh test by giving it more time to retrieve log
blocks on the cache device.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam D. Moss <c@yotes.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10210
Remove some obsolete legacy compat, rename some misnamed, and add some
missing tunables for FreeBSD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10203
The memory and cpu cost of reference count tracking with the current
implementation is significant. For this reason it has always been
disabled by default for the kmods. Apply this same default to user
space so ztest doesn't always incur this performance penalty.
Our intention is to re-enable this by default for ztest once the code
has been optimized. Since we expect to at some point provide a FUSE
implementation we wouldn't want this enabled by default for libzpool.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#10189
This commit makes the L2ARC persistent across reboots. We implement
a light-weight persistent L2ARC metadata structure that allows L2ARC
contents to be recovered after a reboot. This significantly eases the
impact a reboot has on read performance on systems with large caches.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Saso Kiselkov <skiselkov@gmail.com>
Co-authored-by: Jorgen Lundman <lundman@lundman.net>
Co-authored-by: George Amanakis <gamanakis@gmail.com>
Ported-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#925Closes#1823Closes#2672Closes#3744Closes#9582
Set arc_c_min before arc_c_max so that when zfs_arc_min is set lower
than the default allmem/32 zfs_arc_max can also be set lower.
Add warning messages when tunables are being ignored.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10157Closes#10158
By default it's not possible to open a device already owned by an
active vdev. It's necessary to make an exception to this for vdev
split. The FreeBSD platform code will make an exception if
spa_is splitting is set to to true.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10178
Added to prevent a possible deadlock, the following comments from
FreeBSD explain the issue. The comment describing vn_io_fault_uiomove:
/*
* Helper function to perform the requested uiomove operation using
* the held pages for io->uio_iov[0].iov_base buffer instead of
* copyin/copyout. Access to the pages with uiomove_fromphys()
* instead of iov_base prevents page faults that could occur due to
* pmap_collect() invalidating the mapping created by
* vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
* object cleanup revoking the write access from page mappings.
*
* Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
* instead of plain uiomove().
*/
This used for vn_io_fault which has the following motivation:
/*
* The vn_io_fault() is a wrapper around vn_read() and vn_write() to
* prevent the following deadlock:
*
* Assume that the thread A reads from the vnode vp1 into userspace
* buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
* currently not resident, then system ends up with the call chain
* vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
* vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
* which establishes lock order vp1->vn_lock, then vp2->vn_lock.
* If, at the same time, thread B reads from vnode vp2 into buffer buf2
* backed by the pages of vnode vp1, and some page in buf2 is not
* resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
*
* To prevent the lock order reversal and deadlock, vn_io_fault() does
* not allow page faults to happen during VOP_READ() or VOP_WRITE().
* Instead, it first tries to do the whole range i/o with pagefaults
* disabled. If all pages in the i/o buffer are resident and mapped,
* VOP will succeed (ignoring the genuine filesystem errors).
* Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
* i/o in chunks, with all pages in the chunk prefaulted and held
* using vm_fault_quick_hold_pages().
*
* Filesystems using this deadlock avoidance scheme should use the
* array of the held pages from uio, saved in the curthread->td_ma,
* instead of doing uiomove(). A helper function
* vn_io_fault_uiomove() converts uiomove request into
* uiomove_fromphys() over td_ma array.
*
* Since vnode locks do not cover the whole i/o anymore, rangelocks
* make the current i/o request atomic with respect to other i/os and
* truncations.
*/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10177
Linux and FreeBSD have different parameters for tunable proc handler.
This has prevented FreeBSD from implementing the ZFS_MODULE_PARAM_CALL
macro.
To complete the sharing of ZFS_MODULE_PARAM_CALL declarations, create
per-platform definitions of the parameter list, ZFS_MODULE_PARAM_ARGS.
With the declarations wired up we discovered an incorrect scope prefix
for spa_slop_shift, so this is now fixed.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10179
Add a mechanism to wait for delete queue to drain.
When doing redacted send/recv, many workflows involve deleting files
that contain sensitive data. Because of the way zfs handles file
deletions, snapshots taken quickly after a rm operation can sometimes
still contain the file in question, especially if the file is very
large. This can result in issues for redacted send/recv users who
expect the deleted files to be redacted in the send streams, and not
appear in their clones.
This change duplicates much of the zpool wait related logic into a
zfs wait command, which can be used to wait until the internal
deleteq has been drained. Additional wait activities may be added
in the future.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#9707
Increasing l2arc_write_size or l2arc_write_boost can result in
l2arc_write_buffers() not having enough space to perform its writes and
panic zio_write_phys().
Instead of resetting l2ad_hand to l2ad_start at the end of
l2arc_write_buffers() and not taking into account a possible
user-mediated increase of l2arc_write_max, we do this in l2arc_evict(),
right after l2arc_write_size() has run. If there is not enough space to
evict (ie we will exceed l2ad_end) we evict to the end of the device,
reset l2ad_hand to l2ad_start, set l2ad_first to 0 and iterate
l2arc_evict(). We avoid infinite iteration of l2arc_evict() by making
sure in l2arc_write_size() that l2ad_start + size does not exceed
l2ad_end.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10154
Linux changed the default max ARC size to 1/2 of physical memory to
deal with shortcomings of the Linux SLUB allocator. Other platforms
do not require the same logic.
Implement an arc_default_max() function to determine a default max ARC
size in platform code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10155
Make the cityhash code compile into libzfs, in preparation for the new
"zstream" command.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10152
This change adds a separate return code to zfs_ioc_recv that is used
for incomplete streams, in addition to the existing return code for
streams that contain corruption.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#10122
For each WRITE record in the stream, `zfs receive` creates a DMU
transaction (`dmu_tx_create()`) and writes this block's data into the
object. If per-block overheads (as opposed to per-byte overheads)
dominate performance (as is often the case with small recordsize), the
per-dmu-transaction overheads can be significant. For example, in some
workloads the `receieve_writer` thread is 100% on CPU, and more than
half of its CPU time is in these per-tx routines (e.g.
dmu_tx_hold_write, dmu_tx_assign, dmu_tx_commit).
To improve performance of `zfs receive`, this commit batches WRITE
records which are to nearby offsets of the same object, and uses one DMU
transaction to write them all. By default the batch size is 1MB, which
for recordsize=8K reduces the number of DMU transactions by 128x for
full send streams (incrementals will depend on how "clumpy" the changed
blocks are).
This commit improves the performance of `dd if=stream | zfs recv`
from 78,800 blocks/sec to 98,100 blocks/sec (25% improvement).
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10099
The normal lock order is that the dp_config_rwlock must be held before
the ds_opening_lock. For example, dmu_objset_hold() does this.
However, dmu_objset_open_impl() is called with the ds_opening_lock held,
and if the dp_config_rwlock is not already held, it will attempt to
acquire it. This may lead to deadlock, since the lock order is
reversed.
Looking at all the callers of dmu_objset_open_impl() (which is
principally the callers of dmu_objset_from_ds()), almost all callers
already have the dp_config_rwlock. However, there are a few places in
the send and receive code paths that do not. For example:
dsl_crypto_populate_key_nvlist, send_cb, dmu_recv_stream,
receive_write_byref, redact_traverse_thread.
This commit resolves the problem by requiring all callers ot
dmu_objset_from_ds() to hold the dp_config_rwlock. In most cases, the
code has been restructured such that we call dmu_objset_from_ds()
earlier on in the send and receive processes, when we already have the
dp_config_rwlock, and save the objset_t until we need it in the middle
of the send or receive (similar to what we already do with the
dsl_dataset_t). Thus we do not need to acquire the dp_config_rwlock in
many new places.
I also cleaned up code in dmu_redact_snap() and send_traverse_thread().
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#9662Closes#10115
Attempt to run scrub or resilver on a new pool containing only special
allocations (special vdev added on creation) caused infinite loop
because of dsl_scan_should_clear() limiting memory usage to 5% of pool
size, which it calculated accounting only normal allocation class.
Addition of special and just in case dedup classes fixes the issue.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#10106Closes#8694
dnode_special_close() waits for the refcount of dn_holds to go to zero
without holding the dn_mtx. dnode_rele_and_unlock() does the final
remove to dn_holds with dn_mtx being held:
refs = zfs_refcount_remove(&dn->dn_holds, tag);
mutex_exit(&dn->dn_mtx);
So, there is a race condition after the remove until dn_mtx is
dropped. During that time, dnode_destroy() can get called, which ends
up in dnode_dest() calling mutex_destroy() and a panic since the lock
is still held.
This change adds a condvar to wait for the final dnode_rele_and_unlock()
to release the dn_mtx before calling dnode_destroy().
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: John Poduska <jpoduska@datto.com>
Closes#7814Closes#10101
Using zfs with Lustre, an arc_read can trigger kernel memory allocation
that in turn leads to a memory reclaim callback and a deadlock within a
single zfs process. This change uses spl_fstrans_mark and
spl_trans_unmark to prevent the reclaim attempt and the deadlock
(https://zfsonlinux.topicbox.com/groups/zfs-devel/T4db2c705ec1804ba).
The stack trace observed is:
__schedule at ffffffff81610f2e
schedule at ffffffff81611558
schedule_preempt_disabled at ffffffff8161184a
__mutex_lock at ffffffff816131e8
arc_buf_destroy at ffffffffa0bf37d7 [zfs]
dbuf_destroy at ffffffffa0bfa6fe [zfs]
dbuf_evict_one at ffffffffa0bfaa96 [zfs]
dbuf_rele_and_unlock at ffffffffa0bfa561 [zfs]
dbuf_rele_and_unlock at ffffffffa0bfa32b [zfs]
osd_object_delete at ffffffffa0b64ecc [osd_zfs]
lu_object_free at ffffffffa06d6a74 [obdclass]
lu_site_purge_objects at ffffffffa06d7fc1 [obdclass]
lu_cache_shrink_scan at ffffffffa06d81b8 [obdclass]
shrink_slab at ffffffff811ca9d8
shrink_node at ffffffff811cfd94
do_try_to_free_pages at ffffffff811cfe63
try_to_free_pages at ffffffff811d01c4
__alloc_pages_slowpath at ffffffff811be7f2
__alloc_pages_nodemask at ffffffff811bf3ed
new_slab at ffffffff81226304
___slab_alloc at ffffffff812272ab
__slab_alloc at ffffffff8122740c
kmem_cache_alloc at ffffffff81227578
spl_kmem_cache_alloc at ffffffffa048a1fd [spl]
arc_buf_alloc_impl at ffffffffa0befba2 [zfs]
arc_read at ffffffffa0bf0924 [zfs]
dbuf_read at ffffffffa0bf9083 [zfs]
dmu_buf_hold_by_dnode at ffffffffa0c04869 [zfs]
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mark Roper <markroper@gmail.com>
Closes#9987
When doing a zfs send on a dataset with small recordsize (e.g. 8K),
performance is dominated by the per-block overheads. This is especially
true with `zfs send --compressed`, which further reduces the amount of
data sent, for the same number of blocks. Several threads are involved,
but the limiting factor is the `send_prefetch` thread, which is 100% on
CPU.
The main job of the `send_prefetch` thread is to issue zio's for the
data that will be needed by the main thread. It does this by calling
`arc_read(ARC_FLAG_PREFETCH)`. This has an immediate cost of creating
an arc_hdr, which takes around 14% of one CPU. It also induces later
costs by other threads:
* Since the data was only prefetched, dmu_send()->dmu_dump_write() will
need to call arc_read() again to get the data. This will have to
look up the arc_hdr in the hash table and copy the data from the
scatter ABD in the arc_hdr to a linear ABD in arc_buf. This takes
27% of one CPU.
* dmu_dump_write() needs to arc_buf_destroy() This takes 11% of one
CPU.
* arc_adjust() will need to evict this arc_hdr, taking about 50% of one
CPU.
All of these costs can be avoided by bypassing the ARC if the data is
not already cached. This commit changes `zfs send` to check for the
data in the ARC, and if it is not found then we directly call
`zio_read()`, reading the data into a linear ABD which is used by
dmu_dump_write() directly.
The performance improvement is best expressed in terms of how many
blocks can be processed by `zfs send` in one second. This change
increases the metric by 50%, from ~100,000 to ~150,000. When the amount
of data per block is small (e.g. 2KB), there is a corresponding
reduction in the elapsed time of `zfs send >/dev/null` (from 86 minutes
to 58 minutes in this test case).
In addition to improving the performance of `zfs send`, this change
makes `zfs send` not pollute the ARC cache. In most cases the data will
not be reused, so this allows us to keep caching useful data in the MRU
(hit-once) part of the ARC.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10067
