zfsonlinux issue #2217 - zvol minor operations: check snapdev
property before traversing snapshots of a dataset
zfsonlinux issue #3681 - lock order inversion between zvol_open()
and dsl_pool_sync()...zvol_rename_minors()
Create a per-pool zvol taskq for asynchronous zvol tasks.
There are a few key design decisions to be aware of.
* Each taskq must be single threaded to ensure tasks are always
processed in the order in which they were dispatched.
* There is a taskq per-pool in order to keep the pools independent.
This way if one pool is suspended it will not impact another.
* The preferred location to dispatch a zvol minor task is a sync
task. In this context there is easy access to the spa_t and
minimal error handling is required because the sync task must
succeed.
Support for asynchronous zvol minor operations address issue #3681.
Signed-off-by: Boris Protopopov <boris.protopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2217Closes#3678Closes#3681
The existing algorithm selects a preferred leaf vdev based on offset of the zio
request modulo the number of members in the mirror. It assumes the devices are
of equal performance and that spreading the requests randomly over both drives
will be sufficient to saturate them. In practice this results in the leaf vdevs
being under utilized.
The new algorithm takes into the following additional factors:
* Load of the vdevs (number outstanding I/O requests)
* The locality of last queued I/O vs the new I/O request.
Within the locality calculation additional knowledge about the underlying vdev
is considered such as; is the device backing the vdev a rotating media device.
This results in performance increases across the board as well as significant
increases for predominantly streaming loads and for configurations which don't
have evenly performing devices.
The following are results from a setup with 3 Way Mirror with 2 x HD's and
1 x SSD from a basic test running multiple parrallel dd's.
With pre-fetch disabled (vfs.zfs.prefetch_disable=1):
== Stripe Balanced (default) ==
Read 15360MB using bs: 1048576, readers: 3, took 161 seconds @ 95 MB/s
== Load Balanced (zfslinux) ==
Read 15360MB using bs: 1048576, readers: 3, took 297 seconds @ 51 MB/s
== Load Balanced (locality freebsd) ==
Read 15360MB using bs: 1048576, readers: 3, took 54 seconds @ 284 MB/s
With pre-fetch enabled (vfs.zfs.prefetch_disable=0):
== Stripe Balanced (default) ==
Read 15360MB using bs: 1048576, readers: 3, took 91 seconds @ 168 MB/s
== Load Balanced (zfslinux) ==
Read 15360MB using bs: 1048576, readers: 3, took 108 seconds @ 142 MB/s
== Load Balanced (locality freebsd) ==
Read 15360MB using bs: 1048576, readers: 3, took 48 seconds @ 320 MB/s
In addition to the performance changes the code was also restructured, with
the help of Justin Gibbs, to provide a more logical flow which also ensures
vdevs loads are only calculated from the set of valid candidates.
The following additional sysctls where added to allow the administrator
to tune the behaviour of the load algorithm:
* vfs.zfs.vdev.mirror.rotating_inc
* vfs.zfs.vdev.mirror.rotating_seek_inc
* vfs.zfs.vdev.mirror.rotating_seek_offset
* vfs.zfs.vdev.mirror.non_rotating_inc
* vfs.zfs.vdev.mirror.non_rotating_seek_inc
These changes where based on work started by the zfsonlinux developers:
https://github.com/zfsonlinux/zfs/pull/1487
Reviewed by: gibbs, mav, will
MFC after: 2 weeks
Sponsored by: Multiplay
References:
https://github.com/freebsd/freebsd@5c7a6f5dhttps://github.com/freebsd/freebsd@31b7f68dhttps://github.com/freebsd/freebsd@e186f564
Performance Testing:
https://github.com/zfsonlinux/zfs/pull/4334#issuecomment-189057141
Porting notes:
- The tunables were adjusted to have ZoL-style names.
- The code was modified to use ZoL's vd_nonrot.
- Fixes were done to make cstyle.pl happy
- Merge conflicts were handled manually
- freebsd/freebsd@e186f564bc by my
collegue Andriy Gapon has been included. It applied perfectly, but
added a cstyle regression.
- This replaces 556011dbec entirely.
- A typo "IO'a" has been corrected to say "IO's"
- Descriptions of new tunables were added to man/man5/zfs-module-parameters.5.
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4334
6414 vdev_config_sync could be simpler
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/6414https://github.com/illumos/illumos-gate/commit/eb5bb58
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
6815179 zpool import with a large number of LUNs is too slow
6844191 zpool import, scanning of disks should be multi-threaded
References:
https://github.com/illumos/illumos-gate/commit/4f67d75
Porting notes:
- This change was originally never ported to Linux due to it
dependence on the thread pool interface. This patch solves
that issue by switching the code to use the existing taskq
implementation which provides the same basic functionality.
However, in order for this to work properly thread_init()
and thread_fini() must be called around to taskq consumer
to perform the needed thread initialization.
- The check_one_slice, nozpool_all_slices, and check_slices
functions have been disabled for Linux. They are difficult,
but possible, to implement for Linux due to how partitions
are get names. Since this is only an optimization this code
can be added at a latter date.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
4950 files sometimes can't be removed from a full filesystem
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4950https://github.com/illumos/illumos-gate/commit/4bb7380
Porting notes:
- ZoL currently does not log discards to zvols, so the portion of
this patch that modifies the discard logging to mark it as
freeing space has been discarded.
2. may_delete_now had been removed from zfs_remove() in ZoL.
It has been reintroduced.
3. We do not try to emulate vnodes, so the following lines are
not valid on Linux:
mutex_enter(&vp->v_lock);
may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp);
mutex_exit(&vp->v_lock);
This has been replaced with:
mutex_enter(&zp->z_lock);
may_delete_now = atomic_read(&ip->i_count) == 1 && !(zp->z_is_mapped);
mutex_exit(&zp->z_lock);
Ported-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
5045 use atomic_{inc,dec}_* instead of atomic_add_*
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/5045https://github.com/illumos/illumos-gate/commit/1a5e258
Porting notes:
- All changes to non-ZFS files dropped.
- Changes to zfs_vfsops.c dropped because they were Illumos specific.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4220
The fast write mutex is intended to protect accounting, but it is
redundant because all accounting is performed through atomic operations.
It also serializes all metaslab IO behind a mutex, which introduces a
theoretical scaling regression that the Illumos developers did not like
when we showed this to them. Removing it makes the selection of the
metaslab_group lock free as it is on Illumos. The selection is not quite
the same without the lock because the loop races with IO completions,
but any imbalances caused by this are likely to be corrected by
subsequent metaslab group selections.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3643
The zfs_znode_hold_enter() / zfs_znode_hold_exit() functions are used to
serialize access to a znode and its SA buffer while the object is being
created or destroyed. This kind of locking would normally reside in the
znode itself but in this case that's impossible because the znode and SA
buffer may not yet exist. Therefore the locking is handled externally
with an array of mutexs and AVLs trees which contain per-object locks.
In zfs_znode_hold_enter() a per-object lock is created as needed, inserted
in to the correct AVL tree and finally the per-object lock is held. In
zfs_znode_hold_exit() the process is reversed. The per-object lock is
released, removed from the AVL tree and destroyed if there are no waiters.
This scheme has two important properties:
1) No memory allocations are performed while holding one of the z_hold_locks.
This ensures evict(), which can be called from direct memory reclaim, will
never block waiting on a z_hold_locks which just happens to have hashed
to the same index.
2) All locks used to serialize access to an object are per-object and never
shared. This minimizes lock contention without creating a large number
of dedicated locks.
On the downside it does require znode_lock_t structures to be frequently
allocated and freed. However, because these are backed by a kmem cache
and very short lived this cost is minimal.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4106
Add a zfs_object_mutex_size module option to facilitate resizing the
the per-dataset znode mutex array. Increasing this value may help
make the deadlock described in #4106 less common, but this is not a
proper fix. This patch is primarily to aid debugging and analysis.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #4106
3465 ::walk ... | ::<dcmd> misinterprets input as symbol names
3466 ::tsd should handle missing/NULL values better
3467 mdb_ctf_vread() could be more useful
3468 mdb enhancements for zfs development
3470 ::whatis does not print callers from KMF_LITE
3473 mdb_get_module() returns wrong module
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
https://www.illumos.org/issues/3468https://github.com/illumos/illumos-gate/commit/28e4da2
Porting notes:
- The only portion of this patch which applies to ZoL is a small
change to types used in the refcount structure.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4216
Under RHEL6/CentOS6 the default stack size must be increased to 32K
to prevent overflowing the stack when running ztest. This isn't an
issue for other distributions due to either the version of pthreads
or perhaps the compiler. Doubling the stack size resolves the
issue safely for all distribution and leaves us some headroom.
$ sudo -E ztest -V -T 300 -f /var/tmp/
5 vdevs, 7 datasets, 23 threads, 300 seconds...
loading space map for vdev 0 of 1, metaslab 0 of 30 ...
...
loading space map for vdev 0 of 1, metaslab 14 of 30 ...
child died with signal 11
Exited ztest with error 3
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4215
3749 zfs event processing should work on R/O root filesystems
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3749https://github.com/illumos/illumos-gate/commit/3cb69f7
Porting notes:
- [include/sys/spa_impl.h]
- ffe9d38 Add generic errata infrastructure
- 1421c89 Add visibility in to arc_read
- [include/sys/fm/fs/zfs.h]
- 2668527 Add linux events
- 6283f55 Support custom build directories and move includes
- [module/zfs/spa_config.c]
- Updated spa_config_sync() to match illumos with the exception
of a Linux specific block.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6171 dsl_prop_unregister() slows down dataset eviction.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/6171https://github.com/illumos/illumos-gate/commit/03bad06
Porting notes:
- Conflicts
- 3558fd7 Prototype/structure update for Linux
- 2cf7f52 Linux compat 2.6.39: mount_nodev()
- 13fe019 Illumos #3464
- 241b541 Illumos 5959 - clean up per-dataset feature count code
- dsl_prop_unregister() preserved until out of tree consumers
like Lustre can transition to dsl_prop_unregister_all().
- Fixing 'space or tab at end of line' in include/sys/dsl_dataset.h
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
4929 want prevsnap property
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: Matt Amdur <matt.amdur@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4929https://github.com/illumos/illumos-gate/commit/b461c74
Porting notes:
- [include/sys/fs/zfs.h]
- f67d70 Create an 'overlay' property
- 11b9ec Add full SELinux support
- [fs/zfs/dsl_dataset.c]
- This increases the stack size of dsl_dataset_stats() but
nothing has been changed until this is shown to be an issue.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
4891 want zdb option to dump all metadata
Reviewed by: Sonu Pillai <sonu.pillai@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
We'd like a way for zdb to dump metadata in a machine-readable
format, so that we can bring that back from a customer site for
in-house diagnosis. Think of it as a crash dump for zpools,
which can be used for post-mortem analysis of a malfunctioning
pool
References:
https://www.illumos.org/issues/4891https://github.com/illumos/illumos-gate/commit/df15e41
Porting notes:
- [cmd/zdb/zdb.c]
- a5778ea zdb: Introduce -V for verbatim import
- In main() getopt 'opt' variable removed and the code was
brought back in line with illumos.
- [lib/libzpool/kernel.c]
- 1e33ac1 Fix Solaris thread dependency by using pthreads
- f0e324f Update utsname support
- 4d58b69 Fix vn_open/vn_rdwr error handling
- In vn_open() allocate 'dumppath' on heap instead of stack
- Properly handle 'dump_fd == -1' error path
- Free 'realpath' after added vn_dumpdir_code block
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
3749 zfs event processing should work on R/O root filesystems
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3749https://github.com/illumos/illumos-gate/commit/3cb69f7
Porting notes:
- [include/sys/spa_impl.h]
- ffe9d38 Add generic errata infrastructure
- 1421c89 Add visibility in to arc_read
- [include/sys/fm/fs/zfs.h]
- 2668527 Add linux events
- 6283f55 Support custom build directories and move includes
- [module/zfs/spa_config.c]
- Updated spa_config_sync() to match illumos with the exception
of a Linux specific block.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The function sa_update() accepts a 32-bit length parameter and
assigns it to a 16-bit field in sa_bulk_attr_t, potentially
truncating the passed-in value. This could lead to corrupt system
attribute (SA) records getting written to the pool. Add a VERIFY to
sa_update() to detect cases where overflow would occur. The SA length
is limited to 16-bit values by the on-disk format defined by
sa_hdr_phys_t.
The function zfs_sa_set_xattr() is vulnerable to this bug if the
unpacked nvlist of xattrs is less than 64k in size but the packed
size is greater than 64k. Fix this by appropriately checking the
size of the packed nvlist before calling sa_update(). Add error
handling to zpl_xattr_set_sa() to keep the cached list of SA-based
xattrs consistent with the data on disk.
Lastly, zfs_sa_set_xattr() calls dmu_tx_abort() on an assigned
transaction if sa_update() returns an error, but the DMU only allows
unassigned transactions to be aborted. Wrap the sa_update() call in a
VERIFY0, remove the transaction abort, and call dmu_tx_commit()
unconditionally. This is consistent practice with other callers
of sa_update().
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#4150
Both lock types were introduced in SPL to allow some locks to be
taken/released with linux lockdep turned off. See SPL commit for
details.
Add the new lock types to zfs_context.h to allow user space compilation.
Depends on SPL commit 692ae8d
SPL pull request refs/pull/480/head
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3895
This deadlock may manifest itself in slightly different ways but
at the core it is caused by a memory allocation blocking on file-
system reclaim in the zio pipeline. This is normally impossible
because zio_execute() disables filesystem reclaim by setting
PF_FSTRANS on the thread. However, kmem cache allocations may
still indirectly block on file system reclaim while holding the
critical vq->vq_lock as shown below.
To resolve this issue zio_buf_alloc_flags() is introduced which
allocation flags to be passed. This can then be used in
vdev_queue_aggregate() with KM_NOSLEEP when allocating the
aggregate IO buffer. Since aggregating the IO is purely a
performance optimization we want this to either succeed or fail
quickly. Trying too hard to allocate this memory under the
vq->vq_lock can negatively impact performance and result in
this deadlock.
* z_wr_iss
zio_vdev_io_start
vdev_queue_io -> Takes vq->vq_lock
vdev_queue_io_to_issue
vdev_queue_aggregate
zio_buf_alloc -> Waiting on spl_kmem_cache process
* z_wr_int
zio_vdev_io_done
vdev_queue_io_done
mutex_lock -> Waiting on vq->vq_lock held by z_wr_iss
* txg_sync
spa_sync
dsl_pool_sync
zio_wait -> Waiting on zio being handled by z_wr_int
* spl_kmem_cache
spl_cache_grow_work
kv_alloc
spl_vmalloc
...
evict
zpl_evict_inode
zfs_inactive
dmu_tx_wait
txg_wait_open -> Waiting on txg_sync
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3808Closes#3867
Since uio now supports bvec, we can convert bio into uio and reuse
dmu_{read,write}_uio. This way, we can remove some duplicate code.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4078
objsetid is not unique across pool, so using it solely as key would cause
panic when automounting two snapshot on different pools with the same
objsetid. We fix this by adding spa pointer as additional key.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Issue #3948
Issue #3786
Issue #3887
5959 clean up per-dataset feature count code
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/5959https://github.com/illumos/illumos-gate/commit/ca0cc39
Porting notes:
illumos code doesn't check for feature_get_refcount() returning
ENOTSUP (which means feature is disabled) in zdb. zfsonlinux added
a check in https://github.com/zfsonlinux/zfs/commit/784652c
due to #3468. The check was reintroduced here.
Ported-by: Witaut Bajaryn <vitaut.bayaryn@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3965
Provide a generic interface to prefetch ZAP entries by name. This
functionality is being added for external consumers such as Lustre.
It is based of the existing zap_prefetch_uint64() version which is
used by the deduplication code.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#4061
Adding additional entries to the efi conversion array will help prevent
the overwriting of the GPTs of disks with in-use file systems in more
cases. Most notably, this adds partition type 8300 "Linux filesystem"
(0FC63DAF-8483-4772-8E79-3D69D8477DE4), which is often used for ext4 and
btrfs, among others.
This commit itself does nothing to address the underlying problematic
behavior that check_slice() isn't called on partitions of an
unrecognized type, even when they contain a currently mounted file
system.
The additional entries were derived from these two resources:
https://en.wikipedia.org/wiki/GUID_Partition_Tablehttp://sourceforge.net/p/gptfdisk/code/ci/master/tree/parttypes.cc
Signed-off-by: ilovezfs <ilovezfs@icloud.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4016
Currently, the SET_ERROR tracepoint triggers regardless of whether there
is an error or not. On Illumos, SET_ERROR only triggers on an actual
error, which is avoids irrelevant noise. Linux 2.6.38 added support for
conditional tracepoints, so we modify SET_ERROR to use them when they
are avaliable for functionality equivalent to the Illumos functionality.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4043
ZFS incorrectly uses directory-based extended attributes even when
xattr=sa is specified as a dataset property or mount option. Support to
honor temporary mount options including "xattr" was added in commit
0282c4137e. There are two issues with the
mount option handling:
* Libzfs has historically included "xattr" in its list of default mount
options. This overrides the dataset property, so the dataset is always
configured to use directory-based xattrs even when the xattr dataset
property is set to off or sa. Address this by removing "xattr" from
the set of default mount options in libzfs.
* There was no way to enable system attribute-based extended attributes
using temporary mount options. Add the mount options "saxattr" and
"dirxattr" which enable the xattr behavior their names suggest. This
approach has the advantages of mirroring the valid xattr dataset
property values and following existing conventions for mount option
names.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3787
6214 zpools going south
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
References:
https://www.illumos.org/issues/6214http://cr.illumos.org/~webrev/sensille/6214_zpools_going_south/
Porting Notes:
Reintroduce b_compress to the l2arc_buf_hdr_t. In commit b9541d6
the compression flags were moved to the generic b_flags in the
arc_buf_hdr_t. This is a problem because l2arc_compress_buf()
may manipulate the compression flags and this can only be done
safely under the hash lock which is not held. See Illumos 6214
for a detailed analysis of the race.
HDR_GET_COMPRESS() macro was removed from arc_buf_info().
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3757
Internally ZFS keeps a small log to facilitate debugging. By default
the log is disabled, to enable it set zfs_dbgmsg_enable=1. The contents
of the log can be accessed by reading the /proc/spl/kstat/zfs/dbgmsg file.
Writing 0 to this proc file clears the log.
$ echo 1 >/sys/module/zfs/parameters/zfs_dbgmsg_enable
$ echo 0 >/proc/spl/kstat/zfs/dbgmsg
$ zpool import tank
$ cat /proc/spl/kstat/zfs/dbgmsg
1 0 0x01 -1 0 2492357525542 2525836565501
timestamp message
1441141408 spa=tank async request task=1
1441141408 txg 70 open pool version 5000; software version 5000/5; ...
1441141409 spa=tank async request task=32
1441141409 txg 72 import pool version 5000; software version 5000/5; ...
1441141414 command: lt-zpool import tank
Note the zfs_dbgmsg() and dprintf() functions are both now mapped to
the same log. As mentioned above the kernel debug log can be accessed
though the /proc/spl/kstat/zfs/dbgmsg kstat. For user space consumers
log messages are immediately written to stdout after applying the
ZFS_DEBUG environment variable.
$ ZFS_DEBUG=on ./cmd/ztest/ztest -V
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#3728
Internally, zvols are files exposed through the block device API. This
is intended to reduce overhead when things require block devices.
However, the ZoL zvol code emulates a traditional block device in that
it has a top half and a bottom half. This is an unnecessary source of
overhead that does not exist on any other OpenZFS platform does this.
This patch removes it. Early users of this patch reported double digit
performance gains in IOPS on zvols in the range of 50% to 80%.
Comments in the code suggest that the current implementation was done to
obtain IO merging from Linux's IO elevator. However, the DMU already
does write merging while arc_read() should implicitly merge read IOs
because only 1 thread is permitted to fetch the buffer into ARC. In
addition, commercial ZFSOnLinux distributions report that regular files
are more performant than zvols under the current implementation, and the
main consumers of zvols are VMs and iSCSI targets, which have their own
elevators to merge IOs.
Some minor refactoring allows us to register zfs_request() as our
->make_request() handler in place of the generic_make_request()
function. This eliminates the layer of code that broke IO requests on
zvols into a top half and a bottom half. This has several benefits:
1. No per zvol spinlocks.
2. No redundant IO elevator processing.
3. Interrupts are disabled only when actually necessary.
4. No redispatching of IOs when all taskq threads are busy.
5. Linux's page out routines will properly block.
6. Many autotools checks become obsolete.
An unfortunate consequence of eliminating the layer that
generic_make_request() is that we no longer calls the instrumentation
hooks for block IO accounting. Those hooks are GPL-exported, so we
cannot call them ourselves and consequently, we lose the ability to do
IO monitoring via iostat. Since zvols are internally files mapped as
block devices, this should be okay. Anyone who is willing to accept the
performance penalty for the block IO layer's accounting could use the
loop device in between the zvol and its consumer. Alternatively, perf
and ftrace likely could be used. Also, tools like latencytop will still
work. Tools such as latencytop sometimes provide a better view of
performance bottlenecks than the traditional block IO accounting tools
do.
Lastly, if direct reclaim occurs during spacemap loading and swap is on
a zvol, this code will deadlock. That deadlock could already occur with
sync=always on zvols. Given that swap on zvols is not yet production
ready, this is not a blocker.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Add the required kernel side infrastructure to parse arbitrary
mount options. This enables us to support temporary mount
options in largely the same way it is handled on other platforms.
See the 'Temporary Mount Point Properties' section of zfs(8)
for complete details.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#985Closes#3351
Commit 49ddb31506 added the
zfs_arc_average_blocksize parameter to allow control over the size of
the arc hash table. The dbuf hash table's size should be determined
similarly.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3721
The LBA weighting makes sense on rotational media where the outer tracks
have twice the bandwidth of the inner tracks. However, it is detrimental
on nonrotational media such as solid state disks, where the only effect
is to ensure that metaslabs enter the best-fit allocation behavior
sooner, which is detrimental to performance. It also makes no sense on
files where the underlying filesystem can arrange things however it
wants.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3712
Re-factor the .zfs/snapshot auto-mouting code to take in to account
changes made to the upstream kernels. And to lay the groundwork for
enabling access to .zfs snapshots via NFS clients. This patch makes
the following core improvements.
* All actively auto-mounted snapshots are now tracked in two global
trees which are indexed by snapshot name and objset id respectively.
This allows for fast lookups of any auto-mounted snapshot regardless
without needing access to the parent dataset.
* Snapshot entries are added to the tree in zfsctl_snapshot_mount().
However, they are now removed from the tree in the context of the
unmount process. This eliminates the need complicated error logic
in zfsctl_snapshot_unmount() to handle unmount failures.
* References are now taken on the snapshot entries in the tree to
ensure they always remain valid while a task is outstanding.
* The MNT_SHRINKABLE flag is set on the snapshot vfsmount_t right
after the auto-mount succeeds. This allows to kernel to unmount
idle auto-mounted snapshots if needed removing the need for the
zfsctl_unmount_snapshots() function.
* Snapshots in active use will not be automatically unmounted. As
long as at least one dentry is revalidated every zfs_expire_snapshot/2
seconds the auto-unmount expiration timer will be extended.
* Commit torvalds/linux@bafc9b7 caused snapshots auto-mounted by ZFS
to be immediately unmounted when the dentry was revalidated. This
was a consequence of ZFS invaliding all snapdir dentries to ensure that
negative dentries didn't mask new snapshots. This patch modifies the
behavior such that only negative dentries are invalidated. This solves
the issue and may result in a performance improvement.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3589Closes#3344Closes#3295Closes#3257Closes#3243Closes#3030Closes#2841
Since ZoL allows large blocks to be used by volumes, unlike upstream
illumos, the feature flag must be checked prior to volume creation.
This is critical because unlike filesystems, volumes will create a
object which uses large blocks as part of the create. Therefore, it
cannot be safely checked in zfs_check_settable() after the dataset
can been created.
In addition this patch updates the relevant error messages to use
zfs_nicenum() to print the maximum blocksize.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3591
Under Linux filesystem threads responsible for handling I/O are
normally created with the maximum priority. Non-I/O filesystem
processes run with the default priority. ZFS should adopt the
same priority scheme under Linux to maintain good performance
and so that it will complete fairly when other Linux filesystems
are active. The priorities have been updated to the following:
$ ps -eLo rtprio,cls,pid,pri,nice,cmd | egrep 'z_|spl_|zvol|arc|dbu|meta'
- TS 10743 19 -20 [spl_kmem_cache]
- TS 10744 19 -20 [spl_system_task]
- TS 10745 19 -20 [spl_dynamic_tas]
- TS 10764 19 0 [dbu_evict]
- TS 10765 19 0 [arc_prune]
- TS 10766 19 0 [arc_reclaim]
- TS 10767 19 0 [arc_user_evicts]
- TS 10768 19 0 [l2arc_feed]
- TS 10769 39 0 [z_unmount]
- TS 10770 39 -20 [zvol]
- TS 11011 39 -20 [z_null_iss]
- TS 11012 39 -20 [z_null_int]
- TS 11013 39 -20 [z_rd_iss]
- TS 11014 39 -20 [z_rd_int_0]
- TS 11022 38 -19 [z_wr_iss]
- TS 11023 39 -20 [z_wr_iss_h]
- TS 11024 39 -20 [z_wr_int_0]
- TS 11032 39 -20 [z_wr_int_h]
- TS 11033 39 -20 [z_fr_iss_0]
- TS 11041 39 -20 [z_fr_int]
- TS 11042 39 -20 [z_cl_iss]
- TS 11043 39 -20 [z_cl_int]
- TS 11044 39 -20 [z_ioctl_iss]
- TS 11045 39 -20 [z_ioctl_int]
- TS 11046 39 -20 [metaslab_group_]
- TS 11050 19 0 [z_iput]
- TS 11121 38 -19 [z_wr_iss]
Note that under Linux the meaning of a processes priority is inverted
with respect to illumos. High values on Linux indicate a _low_ priority
while high value on illumos indicate a _high_ priority.
In order to preserve the logical meaning of the minclsyspri and
maxclsyspri macros when they are used by the illumos wrapper functions
their values have been inverted. This way when changes are merged
from upstream illumos we won't need to remember to invert the macro.
It could also lead to confusion.
This patch depends on https://github.com/zfsonlinux/spl/pull/466.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#3607
5817 change type of arcs_size from uint64_t to refcount_t
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
https://www.illumos.org/issues/5817https://github.com/illumos/illumos-gate/commit/2fd872a
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
5376 arc_kmem_reap_now() should not result in clearing arc_no_grow
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5376https://github.com/illumos/illumos-gate/commit/2ec99e3
Porting Notes:
The good news is that many of the recent changes made upstream to the
ARC tackled issues previously observed by ZoL with similar solutions.
The bad news is those solution weren't identical to the ones we applied.
This patch is designed to split the difference and apply as much of the
upstream work as possible.
* The arc_available_memory() function was removed previous in ZoL but
due to the upstream changes it makes sense to add it back. This function
has been customized for Linux so that it can be used to determine a low
memory. This provides the same basic functionality as the illumos version
allowing us to minimize changes through the rest of the code base. The
exact mechanism used to detect a low memory state remains unchanged so
this change isn't a significant as it might first appear.
* This patch includes the long standing fix for arc_shrink() which was
originally proposed in #2167. Since there were related changes to this
function it made sense to include that work.
* The arc_init() function has been re-factored. As before it sets sane
default values for the ARC but then calls arc_tuning_update() to apply
user specific tuning made via module options. The arc_tuning_update()
function is then called periodically by the arc_reclaim_thread() to
apply changes to the tunings made during normal operation.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3616Closes#2167
5661 ZFS: "compression = on" should use lz4 if feature is enabled
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed by: Xin LI <delphij@freebsd.org>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://github.com/illumos/illumos-gate/commit/db1741fhttps://www.illumos.org/issues/5661
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3571
