Pool-wide metadata is stored in the MOS (Meta Object Set). This
metadata is stored in triplicate, in addition to any pool-level
reduncancy (e.g. RAIDZ). However, if all 3+ copies of this metadata are
not available, we can still get EIO/ECKSUM when reading from the MOS.
If we encounter such an error in syncing context, we have typically
already committed to making a change that we now can't do because of the
corrupt/missing metadata. We typically "handle" this with a `VERIFY()`
or `zfs_panic_recover()`. This prevents the system from continuing on
in an undefined state, while minimizing the amount of error-handling
code.
However, there are some code paths that ignore these i/o errors, or
`ASSERT()` that they don't happen. Since assertions are disabled on
non-debug builds, they effectively ignore them as well. This can lead
to ZFS continuing on in an incorrect state, potentially leading to
on-disk inconsistencies.
This commit adds handling for these i/o errors on MOS metadata,
typically with a `VERIFY()`:
* Handle error return from `zap_cursor_retrieve()` in 4 places in
`dsl_deadlist.c`.
* Handle error return from `zap_contains()` in `dsl_dir_hold_obj()`.
Turns out this call isn't necessary because we can always call
`zap_lookup()`.
* Handle error return from `zap_lookup()` in `dsl_fs_ss_limit_check()`.
* Handle error return from `zap_remove()` in `dsl_dir_rename_sync()`.
* Handle error return from `zap_lookup()` in
`dsl_dir_remove_livelist()`.
* Handle error return from `dsl_process_sub_livelist()` in
`spa_livelist_delete_cb()`.
Additionally:
* Augment the internal history log message for `zfs destroy` to note
which method is used (e.g. bptree, livelist, or, synchronous) and the
mintxg.
* Correct a comment in `dbuf_init()`.
* Correct indentation in `dsl_dir_remove_livelist()`.
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10643
In case the L2ARC rebuild was canceled, do not log to spa history
log as the pool may be in the process of being removed and a panic
may occur:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:spa_history_log_internal+0xb1/0x120 [zfs]
Call Trace:
l2arc_rebuild+0x464/0x7c0 [zfs]
l2arc_dev_rebuild_start+0x2d/0x130 [zfs]
? l2arc_rebuild+0x7c0/0x7c0 [zfs]
thread_generic_wrapper+0x78/0xb0 [spl]
kthread+0xfb/0x130
? IS_ERR+0x10/0x10 [spl]
? kthread_park+0x90/0x90
ret_from_fork+0x35/0x40
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10659
ZFS recv should return a useful error message when an invalid index
property value is provided in the send stream properties nvlist
With a compression= property outside of the understood range:
Before:
```
receiving full stream of zof/zstd_send@send2 into testpool/recv@send2
internal error: Invalid argument
Aborted (core dumped)
```
Note: the recv completes successfully, the abort() is likely just to
make it easier to track the unexpected error code.
After:
```
receiving full stream of zof/zstd_send@send2 into testpool/recv@send2
cannot receive compression property on testpool/recv: invalid property
value received 28.9M stream in 1 seconds (28.9M/sec)
```
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#10631
A collection of header changes to enable FreeBSD to build
with vendored OpenZFS.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10635
The ARC shrinker callback `arc_shrinker_count/_scan()` is invoked by the
kernel's shrinker mechanism when the system is running low on free
pages. This happens via 2 code paths:
1. "direct reclaim": The system is attempting to allocate a page, but we
are low on memory. The ARC shrinker callback is invoked from the
page-allocation code path.
2. "indirect reclaim": kswapd notices that there aren't many free pages,
so it invokes the ARC shrinker callback.
In both cases, the kernel's shrinker code requests that the ARC shrinker
callback release some of its cache, and then it measures how many pages
were released. However, it's measurement of released pages does not
include pages that are freed via `__free_pages()`, which is how the ARC
releases memory (via `abd_free_chunks()`). Rather, the kernel shrinker
code is looking for pages to be placed on the lists of reclaimable pages
(which is separate from actually-free pages).
Because the kernel shrinker code doesn't detect that the ARC has
released pages, it may call the ARC shrinker callback many times,
resulting in the ARC "collapsing" down to `arc_c_min`. This has several
negative impacts:
1. ZFS doesn't use RAM to cache data effectively.
2. In the direct reclaim case, a single page allocation may wait a long
time (e.g. more than a minute) while we evict the entire ARC.
3. Even with the improvements made in 67c0f0dedc ("ARC shrinking blocks
reads/writes"), occasionally `arc_size` may stay above `arc_c` for the
entire time of the ARC collapse, thus blocking ZFS read/write operations
in `arc_get_data_impl()`.
To address these issues, this commit limits the ways that the ARC
shrinker callback can be used by the kernel shrinker code, and mitigates
the impact of arc_is_overflowing() on ZFS read/write operations.
With this commit:
1. We limit the amount of data that can be reclaimed from the ARC via
the "direct reclaim" shrinker. This limits the amount of time it takes
to allocate a single page.
2. We do not allow the ARC to shrink via kswapd (indirect reclaim).
Instead we rely on `arc_evict_zthr` to monitor free memory and reduce
the ARC target size to keep sufficient free memory in the system. Note
that we can't simply rely on limiting the amount that we reclaim at once
(as for the direct reclaim case), because kswapd's "boosted" logic can
invoke the callback an unlimited number of times (see
`balance_pgdat()`).
3. When `arc_is_overflowing()` and we want to allocate memory,
`arc_get_data_impl()` will wait only for a multiple of the requested
amount of data to be evicted, rather than waiting for the ARC to no
longer be overflowing. This allows ZFS reads/writes to make progress
even while the ARC is overflowing, while also ensuring that the eviction
thread makes progress towards reducing the total amount of memory used
by the ARC.
4. The amount of memory that the ARC always tries to keep free for the
rest of the system, `arc_sys_free` is increased.
5. Now that the shrinker callback is able to provide feedback to the
kernel's shrinker code about our progress, we can safely enable
the kswapd hook. This will allow the arc to receive notifications
when memory pressure is first detected by the kernel. We also
re-enable the appropriate kstats to track these callbacks.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10600
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#10636
When a clone is promoted, its livelist is no longer accurate, so it is
discarded. If the clone's origin is also a clone (i.e. we are promoting
a clone of a clone), then the origin's livelist is also no longer
accurate, so it should be discarded, but the code doesn't actually do
that.
Consider a pool with:
* Filesystem A
* Clone B, a clone of A
* Clone C, a clone of B
If we promote C, it discards C's livelist. It should discard B's
livelist, but that is not happening. The impact is that when B is
destroyed, we use the livelist to find the blocks to free, but the
livelist is no longer correct so we end up freeing blocks that are still
in use by C. The incorrectly-freed blocks can be reallocated causing
checksum errors. And when C is destroyed it can double-free the
incorrectly-freed blocks.
The problem is that we remove the livelist of `origin_ds->ds_dir`, but
the origin snapshot has already been moved to the promoted dsl_dir. So
this is actually trying to remove the livelist of the promoted dsl_dir,
which was already removed. As explained in a comment in the beginning
of `dsl_dataset_promote_sync()`, we need to use the saved `odd` for the
origin's dsl_dir.
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10652
In `vdev_load()`, we look up several entries in the `vdev_top_zap`
object. In most cases, if we encounter an i/o error, it will be
returned to the caller. However, when handling
`VDEV_TOP_ZAP_ALLOCATION_BIAS`, if we get an i/o error, we may continue
on, which in theory could cause us to not realize that a vdev should be
used only for `special` allocations.
In practice, if we encountered an i/o error while looking for
`VDEV_TOP_ZAP_ALLOCATION_BIAS` in the `vdev_top_zap`, we'd also get an
i/o error while looking for other entries in the same object, and thus
the zpool open/import would fail. Therefore the impact of this problem
is negligible.
This commit adds error handling for i/o errors while accessing the
`vdev_top_zap`, so that we aren't relying on unrelated code to fail for
us.
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10637
Renamed to avoid conflicting with refcount.h when a different
implementation is already provided by the platform.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10620
When debugging issues or generally analyzing the runtime of
a system it would be nice to be able to tell the different
ZTHRs running by name rather than having to analyze their
stack.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#10630
FreeBSD defines _BIG_ENDIAN BIG_ENDIAN _LITTLE_ENDIAN
LITTLE_ENDIAN on every architecture. Trying to do
cross builds whilst hiding this from ZFS has proven
extremely cumbersome.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10621
This is a step toward being able to vendor the OpenZFS code in FreeBSD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10625
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10623
By design a gang ABD can not have another gang ABD as a child. This is
to make sure the logical offset in a gang ABD is consistent with the
individual ABDS it contains as children. If a gang ABD is added as a
child of a gang ABD we will add the individual children of the gang ABD
to the parent gang ABD. This allows for a consistent view of offsets
within the parent gang ABD.
Reviewed-by: Mark Maybee <mmaybee@cray.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#10430
Set the initial max sizes to ULONG_MAX to allow the caches to grow
with the ARC.
Recalculate the metadata cache size on demand so it can adapt, too.
Update descriptions in zfs-module-parameters(5).
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10563Closes#10610
The process of evicting data from the ARC is referred to as
`arc_adjust`.
This commit changes the term to `arc_evict`, which is more specific.
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10592
The SPL kmem_cache implementation provides a mechanism, `skc_reclaim`,
whereby individual caches can register a callback to be invoked when
there is memory pressure. This mechanism is used in only one place: the
ARC registers the `hdr_recl()` reclaim function. This function wakes up
the `arc_reap_zthr`, whose job is to call `kmem_cache_reap()` and
`arc_reduce_target_size()`.
The `skc_reclaim` callbacks are invoked only by shrinker callbacks and
`arc_reap_zthr`, and only callback only wakes up `arc_reap_zthr`. When
called from `arc_reap_zthr`, waking `arc_reap_zthr` is a no-op. When
called from shrinker callbacks, we are already aware of memory pressure
and responding to it. Therefore there is little benefit to ever calling
the `hdr_recl()` `skc_reclaim` callback.
The `arc_reap_zthr` also wakes once a second, and if memory is low when
allocating an ARC buffer. Therefore, additionally waking it from the
shrinker calbacks has little benefit.
The shrinker callbacks can be invoked very frequently, e.g. 10,000 times
per second. Additionally, for invocation of the shrinker callback,
skc_reclaim is invoked many times. Therefore, this mechanism consumes
significant amounts of CPU time.
The kmem_cache shrinker calls `spl_kmem_cache_reap_now()`, which,
in addition to invoking `skc_reclaim()`, does two things to attempt to
free pages for use by the system:
1. Return free objects from the magazine layer to the slab layer
2. Return entirely-free slabs to the page layer (i.e. free pages)
These actions apply only to caches implemented by the SPL, not those
that use the underlying kernel SLAB/SLUB caches. The SPL caches are
used for objects >=32KB, which are primarily linear ABD's cached in the
DBUF cache.
These actions (freeing objects from the magazine layer and returning
entirely-free slabs) are also taken whenever a `kmem_cache_free()` call
finds a full magazine. So there would typically be zero entirely-free
slabs, and the number of objects in magazines is limited (typically no
more than 64 objects per magazine, and there's one magazine per CPU).
Therefore the benefit of `spl_kmem_cache_reap_now()`, while nonzero, is
modest.
We also call `spl_kmem_cache_reap_now()` from the `arc_reap_zthr`, when
memory pressure is detected. Therefore, calling
`spl_kmem_cache_reap_now()` from the kmem_cache shrinker is not needed.
This commit removes the `skc_reclaim` mechanism, its only callback
`hdr_recl()`, and the kmem_cache shrinker callback.
Reviewed-By: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10576
Livelists and spacemaps are data structures that are logs of allocations
and frees. Livelists entries are block pointers (blkptr_t). Spacemaps
entries are ranges of numbers, most often used as to track
allocated/freed regions of metaslabs/vdevs.
These data structures can become self-inconsistent, for example if a
block or range can be "double allocated" (two allocation records without
an intervening free) or "double freed" (two free records without an
intervening allocation).
ZDB (as well as zfs running in the kernel) can detect these
inconsistencies when loading livelists and metaslab. However, it
generally halts processing when the error is detected.
When analyzing an on-disk problem, we often want to know the entire set
of inconsistencies, which is not possible with the current behavior.
This commit adds a new flag, `zdb -y`, which analyzes the livelist and
metaslab data structures and displays all of their inconsistencies.
Note that this is different from the leak detection performed by
`zdb -b`, which checks for inconsistencies between the spacemaps and the
tree of block pointers, but assumes the spacemaps are self-consistent.
The specific checks added are:
Verify livelists by iterating through each sublivelists and:
- report leftover FREEs
- report double ALLOCs and double FREEs
- record leftover ALLOCs together with their TXG [see Cross Check]
Verify spacemaps by iterating over each metaslab and:
- iterate over spacemap and then the metaslab's entries in the
spacemap log, then report any double FREEs and double ALLOCs
Verify that livelists are consistenet with spacemaps. The space
referenced by livelists (after using the FREE's to cancel out
corresponding ALLOCs) should be allocated, according to the spacemaps.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-66031
Closes#10515
Our QE team during automated API testing hit deadlock in ZFS, caused
by lock order reversal. From one side dsl_sync_task_sync() locks
dp_config_rwlock as writer and calls spa_sync_props(), which waits
for spa_props_lock. From another spa_prop_get() locks spa_props_lock
and then calls dsl_pool_config_enter(), trying to lock dp_config_rwlock
as reader.
This patch makes spa_prop_get() lock dp_config_rwlock before
spa_props_lock, making the order consistent.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#10553
On linux the list debug code has been setting off a failure when
checking that the node->next->prev value is pointing back at the node.
At times this check evaluates to 0xdead. When removing a child from a
gang ABD we must acquire the child's abd_mtx to make sure that the
same ABD is not being added to another gang ABD while it is being
removed from a gang ABD. This fixes a race condition when checking
if an ABDs link is already active and part of another gang ABD before
adding it to a gang.
Added additional debug code for the gang ABD in abd_verify() to make
sure each child ABD has active links. Also check to make sure another
gang ABD is not added to a gang ABD.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#10511
The filesystem_limit and snapshot_limit properties limit the number of
filesystems or snapshots that can be created below this dataset.
According to the manpage, "The limit is not enforced if the user is
allowed to change the limit." Two types of users are allowed to change
the limit:
1. Those that have been delegated the `filesystem_limit` or
`snapshot_limit` permission, e.g. with
`zfs allow USER filesystem_limit DATASET`. This works properly.
2. A user with elevated system privileges (e.g. root). This does not
work - the root user will incorrectly get an error when trying to create
a snapshot/filesystem, if it exceeds the `_limit` property.
The problem is that `priv_policy_ns()` does not work if the `cred_t` is
not that of the current process. This happens when
`dsl_enforce_ds_ss_limits()` is called in syncing context (as part of a
sync task's check func) to determine the permissions of the
corresponding user process.
This commit fixes the issue by passing the `task_struct` (typedef'ed as
a `proc_t`) to syncing context, and then using `has_capability()` to
determine if that process is privileged. Note that we still need to
pass the `cred_t` to syncing context so that we can check if the user
was delegated this permission with `zfs allow`.
This problem only impacts Linux. Wrappers are added to FreeBSD but it
continues to use `priv_check_cred()`, which works on arbitrary `cred_t`.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8226Closes#10545
In case l2arc_write_done() handles a zio that was not successful check
that the list of log block pointers is not empty when restoring them
in the device header. Otherwise zero them out. In any case perform the
actual write updating the device header after the zio of
l2arc_write_buffers() completes as l2arc_write_done() may have touched
the memory holding the log block pointers in the device header.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#10540Closes#10543
zfs_rangelock_tryenter() bails immediately instead of waiting for the
lock to become available. This will be used to resolve a deadlock in
the FreeBSD page-in code. No functional change intended.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#10519
The device_rebuild feature enables sequential reconstruction when
resilvering. Mirror vdevs can be rebuilt in LBA order which may
more quickly restore redundancy depending on the pools average block
size, overall fragmentation and the performance characteristics
of the devices. However, block checksums cannot be verified
as part of the rebuild thus a scrub is automatically started after
the sequential resilver completes.
The new '-s' option has been added to the `zpool attach` and
`zpool replace` command to request sequential reconstruction
instead of healing reconstruction when resilvering.
zpool attach -s <pool> <existing vdev> <new vdev>
zpool replace -s <pool> <old vdev> <new vdev>
The `zpool status` output has been updated to report the progress
of sequential resilvering in the same way as healing resilvering.
The one notable difference is that multiple sequential resilvers
may be in progress as long as they're operating on different
top-level vdevs.
The `zpool wait -t resilver` command was extended to wait on
sequential resilvers. From this perspective they are no different
than healing resilvers.
Sequential resilvers cannot be supported for RAIDZ, but are
compatible with the dRAID feature being developed.
As part of this change the resilver_restart_* tests were moved
in to the functional/replacement directory. Additionally, the
replacement tests were renamed and extended to verify both
resilvering and rebuilding.
Original-patch-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: John Poduska <jpoduska@datto.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#10349
Fix header conflicts when building zfs with openzfs as a vendor import.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#10497
OS-specific code (e.g. under `module/os/linux`) does not need to share
its code structure with any other operating systems. In particular, the
ARC and kmem code need not be similar to the code in illumos, because we
won't be syncing this OS-specific code between operating systems. For
example, if/when illumos support is added to the common repo, we would
add a file `module/os/illumos/zfs/arc_os.c` for the illumos versions of
this code.
Therefore, we can simplify the code in the OS-specific ARC and kmem
routines.
These changes do not impact system behavior, they are purely code
cleanup. The changes are:
Arenas are not used on Linux or FreeBSD (they are always `NULL`), so
`heap_arena`, `zio_arena`, and `zio_alloc_arena` can be removed, along
with code that uses them.
In `arc_available_memory()`:
* `desfree` is unused, remove it
* rename `freemem` to avoid conflict with pre-existing `#define`
* remove checks related to arenas
* use units of bytes, rather than converting from bytes to pages and
then back to bytes
`SPL_KMEM_CACHE_REAP` is unused, remove it.
`skc_reap` is unused, remove it.
The `count` argument to `spl_kmem_cache_reap_now()` is unused, remove
it.
`vmem_size()` and associated type and macros are unused, remove them.
In `arc_memory_throttle()`, use a less confusing variable name to store
the result of `arc_free_memory()`.
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#10499
ZFS registers a memory hook, `__arc_shrinker_func`, which is supposed to
allow the ARC to shrink when the kernel experiences memory pressure.
The ARC shrinker changes `arc_c` via a call to
`arc_reduce_target_size()`. Before commit 3ec34e5527, the ARC
shrinker would also evict data from the ARC to bring `arc_size` down to
the new `arc_c`. However, that commit (seemingly inadvertently) made it
so that the ARC shrinker no longer evicts any data or waits for eviction
to complete.
Repeated calls to the ARC shrinker can reduce `arc_c` drastically, often
all the way to `arc_c_min`. Since it doesn't wait for the actual
eviction of data from the ARC, this creates a situation where `arc_size`
is more than `arc_c` for the several seconds/minutes it takes for
`arc_adjust_zthr` to evict data from the ARC. During this time,
arc_get_data_impl() will block, so ZFS can't process read/write requests
(e.g. from iSCSI, NFS, or read/write syscalls).
To ensure that `arc_c` doesn't shrink faster than the adjust thread can
keep up, this commit makes the ARC shrinker wait for the eviction to
complete, resulting in similar behavior to what we had before commit
3ec34e5527.
Note: commit 3ec34e5527 is `OpenZFS 9284 - arc_reclaim_thread
has 2 jobs` and was integrated in December 2018, and is part of ZoL
0.8.x but not 0.7.x.
Additionally, when the ARC size is reduced drastically, the
`arc_adjust_zthr` can be on-CPU for many seconds without blocking. Any
threads that are bound to the same CPU that arc_adjust_zthr is running
on will not able to run for a long time.
To ensure that CPU-bound threads can make progress, this commit changes
`arc_evict_state_impl()` make a voluntary preemption call,
`cond_resched()`.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-70703
Closes#10496
This tunable required a handler to be implemented for
ZFS_MODULE_PARAM_CALL.
Add the handler so the tunable can be declared in common code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#10490
Include the header with prototypes in the file that provides definitions
as well, to catch any mismatch between prototype and definition.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes#10470
Mark functions used only in the same translation unit as static. This
only includes functions that do not have a prototype in a header file
either.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes#10470
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
