Commit Graph

1397 Commits

Author SHA1 Message Date
Alan Somers
cbedc01c9a Fix race condition involving ZFS remove events
When a ZFS drive disappears, ZFS sends a resource.fs.zfs.removed event to
userland. A userland program like zfsd(8) can use that event, for example to
activate a hotspare. The current code contains a race condition: vdev_geom
will sent the sysevent _before_ spa.c would update the vdev's status,
causing userland processes to see pool state that does not reflect the
device removal. This change moves the sysevent to spa.c, closing the race.

Reviewed by:	delphij, Sean Eric Fagan
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D4902
2016-01-14 18:19:05 +00:00
Alan Somers
53f6862723 Fix importing l2arc device by guid
After r292066, vdev_geom verifies both the vdev and pool guids of device
labels during open. However, spare and l2arc devices don't have pool guids,
so opening them by guid will fail (opening by path, when the pathname is
known, still succeeds). This change allows a vdev to be opened by guid if
the label contains no pool_guid, which is the case for inactive spares and
l2arc devices.

PR:		292066
Reported by:	delphij
Reviewed by:	delphij, smh
MFC after:	2 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D4861
2016-01-11 22:15:46 +00:00
Alan Somers
4e7787a9e9 Record physical path information in ZFS Vdevs
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c:
	If available, record the physical path of a vdev in ZFS meta-data.
	Do this both when opening the vdev, and when receiving an attribute
	change notification from GEOM.

	Make vdev_geom_close() synchronous instead of deferring its work to
	a GEOM event handler. There is no benefit to deferring the work and
	this prevents a future open call from referencing a consumer that is
	scheduled for destruction. The close followed by an immediate open
	will occur during a vdev reprobe triggered by any type of I/O error.

	Consolidate vdev_geom_close() and vdev_geom_detach() into
	vdev_geom_close() and vdev_geom_close_locked(). This also moves the
	cross linking operations between vdev and GEOM consumer into a
	single place (linking in vdev_geom_attach() and unlinking in
	vdev_geom_close_locked()).

Submitted by:	gibbs, asomers
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D4524
2016-01-11 17:57:26 +00:00
Steven Hartland
9697b154f2 Fix const conversion warning in lz4_decompress
Fix const conversion warning in lz4_decompress which shows when warnings
are enabled (to be done later).

MFC after:	2 weeks
X-MFC-With:	r293268
Sponsored by:	Multiplay
2016-01-06 20:28:09 +00:00
Allan Jude
7a3f5d11fb Replace sys/crypto/sha2/sha2.c with lib/libmd/sha512c.c
cperciva's libmd implementation is 5-30% faster

The same was done for SHA256 previously in r263218

cperciva's implementation was lacking SHA-384 which I implemented, validated against OpenSSL and the NIST documentation

Extend sbin/md5 to create sha384(1)

Chase dependancies on sys/crypto/sha2/sha2.{c,h} and replace them with sha512{c.c,.h}

Reviewed by:	cperciva, des, delphij
Approved by:	secteam, bapt (mentor)
MFC after:	2 weeks
Sponsored by:	ScaleEngine Inc.
Differential Revision:	https://reviews.freebsd.org/D3929
2015-12-27 17:33:59 +00:00
Andrew Turner
06ef48781d Be stricter on which functions we can probe with FBT. We now only check the
first instruction to see if it's either a pushm with lr, or a sub with sp.
The former is the common case, with the latter used with va_args.

This removes 12 probes. These are all hand-written assembly, with a few C
functions with no stack usage.

Submitted by:	Howard Su <howard0su@gmail.com>
Differential Revision:	https://reviews.freebsd.org/D4419
2015-12-23 17:54:19 +00:00
Mark Johnston
8ff6d9dd22 Support an arbitrary number of arguments to DTrace syscall probes.
Rather than pushing all eight possible arguments into dtrace_probe()'s
stack frame, make the syscall_args struct for the current syscall available
via the current thread. Using a custom getargval method for the systrace
provider, this allows any syscall argument to be fetched, even in kernels
that have modified the maximum number of system call arguments.

Sponsored by:	EMC / Isilon Storage Division
2015-12-17 00:00:27 +00:00
Gleb Smirnoff
f17f88d3e0 Fix breakage caused by r292373 in ZFS/FUSE/NFS/SMBFS.
With the new VOP_GETPAGES() KPI the "count" argument counts pages already,
and doesn't need to be translated from bytes to pages.

While here make it consistent that *rbehind and *rahead are updated only
if we doesn't return error.

Pointy hat to:	glebius
2015-12-16 23:48:50 +00:00
Mark Johnston
feea513564 Remove the unused systrace device file and fix style bugs.
MFC after:	1 week
2015-12-16 23:46:27 +00:00
Gleb Smirnoff
b0cd20172d A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES().
o With new KPI consumers can request contiguous ranges of pages, and
  unlike before, all pages will be kept busied on return, like it was
  done before with the 'reqpage' only. Now the reqpage goes away. With
  new interface it is easier to implement code protected from race
  conditions.

  Such arrayed requests for now should be preceeded by a call to
  vm_pager_haspage() to make sure that request is possible. This
  could be improved later, making vm_pager_haspage() obsolete.

  Strenghtening the promises on the business of the array of pages
  allows us to remove such hacks as swp_pager_free_nrpage() and
  vm_pager_free_nonreq().

o New KPI accepts two integer pointers that may optionally point at
  values for read ahead and read behind, that a pager may do, if it
  can. These pages are completely owned by pager, and not controlled
  by the caller.

  This shifts the UFS-specific readahead logic from vm_fault.c, which
  should be file system agnostic, into vnode_pager.c. It also removes
  one VOP_BMAP() request per hard fault.

Discussed with:	kib, alc, jeff, scottl
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-12-16 21:30:45 +00:00
Alan Somers
670ffd5e5c Change an important error message from ZFS_LOG to printf
Submitted by:	gibbs
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
2015-12-11 00:04:13 +00:00
Alan Somers
62ac7dd2bf During vdev_geom_open, require that the vdev guids match the device's label
except during split, add, or create operations. This fixes a bug where the
wrong disk could be returned, and higher layers of ZFS would immediately
eject it again.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c:
	o When opening by GUID, require both the pool and vdev GUIDs to
	  match.  While it is highly unlikely for two vdevs to have the same
	  vdev GUIDs, the ZFS storage pool allocator only guarantees they
	  are unique within a pool.

	o Modify the open behavior to:
	  - If we are opening a vdev that hasn't previously been opened,
	    open by path without checking GUIDs.
	  - Otherwise, open by path and verify GUIDs.
	  - If that fails, search all geom providers for a device with
	    matching GUIDs.
	  - If that fails, return ENOENT.

Submitted by:	gibbs, asomers
Reviewed by:	smh
MFC after:	4 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D4486
2015-12-10 21:46:21 +00:00
Mark Johnston
1639290749 MFV r289003:
6271 dtrace caused excessive fork time

Author: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Gordon Ross <gwr@nexenta.com>

illumos/illumos-gate@7bd3c1d12d
2015-12-07 21:49:32 +00:00
Mark Johnston
6e0f204c3f Modify DTRACEHIOC_ADDDOF to copy the DOF section from the target process.
r281257 added support for lazyload mode by allowing dtrace(1) to register
a DOF section on behalf of a traced process. This was implemented by
having libdtrace copy the DOF section into a heap-allocated buffer and
passing its address to the ioctl handler. However, DTrace uses the DOF
section address as a lookup key in certain cases, so the ioctl handler
should be given the target process' DOF section address instead. This
change modifies the ADDDOF handler to copy the DOF section in from the
target process, rather than from dtrace(1).
2015-12-07 21:44:05 +00:00
Mark Johnston
711fbd17ec Add helper functions proc_readmem() and proc_writemem().
These helper functions can be used to read in or write a buffer from or to
an arbitrary process' address space. Without them, this can only be done
using proc_rwmem(), which requires the caller to fill out a uio. This is
onerous and results in code duplication; the new functions provide a simpler
interface which is sufficient for most existing callers of proc_rwmem().

This change also adds a manual page for proc_rwmem() and the new functions.

Reviewed by:	jhb, kib
Differential Revision:	https://reviews.freebsd.org/D4245
2015-12-07 21:33:15 +00:00
Andrew Turner
5cde34a0ff Allow the artificial profile frames to be adjusted as needed by the user.
While here update for armv6 to a tested value.

Submitted by:	Howard Su <howard0su@gmail.com>
Reviewed by:	stat
Differential Revision:	https://reviews.freebsd.org/D4315
2015-12-05 10:00:01 +00:00
Andrew Turner
c218815337 Move the check to see if we are tracing a function with the DTrace Function
Boundary Trace to assembly to reduce the overhead of these checks.

Submitted by:	Howard Su <howard0su@gmail.com>
Relnotes:	Yes
Differential Revision:	https://reviews.freebsd.org/D4266
2015-12-05 09:32:36 +00:00
Stanislav Sedov
314eeef290 Make the number of fasttrap probes and the size of the trace points hash table
tunable via sysctl or kernel tunables.

Illumos allows this parameters to be changed via the fasttrap.conf configuration
file, but FreeBSD code hardcoded the parameters.  Expose them under
the kern.dtrace.fasttrap sysctl tree.

MFC after:	2 weeks
2015-12-01 00:24:54 +00:00
Mark Johnston
4d7296f9aa Fix a bug in the amd64 dtrace_getarg() implementation: when unwinding the
stack, take into account the copy of rsi pushed between the breakpoint
trapframe and the dtrace_invop frame. Prior to r287644, this was covered
by the fact that sizeof(struct amd64_frame) was 24 rather than 16.

Reported by:	smh
2015-11-19 05:33:15 +00:00
Steven Hartland
465fed1c17 Switch zfs_panic_recover to panic for bad DVA
As reported by Coverity a null pointer de-reference panic would be triggered
when zfs_recover was set so switch to straight panic as it can never be
recovered.

Reported by: Coverity Scan
MFC after:	1
X-MFC-With:	r290401
Sponsored by:	Multiplay
2015-11-06 20:45:19 +00:00
Steven Hartland
d0d400133f Provide information about bad DVA
Provide information about which vdev has an issue with a bad DVA.

MFC after:	1 week
Sponsored by:	Multiplay
2015-11-05 17:12:41 +00:00
Steven Hartland
ab66c9067a Allow zfs_recover to be changed at runtime
MFC after:	1 week
Sponsored by:	Multiplay
2015-11-05 17:00:42 +00:00
Andrew Turner
e5ca5f2abd Fix the open solaris atomic functions on arm64. Without this we may use the
wrong value in the comparison, leading to incorrectly setting the new
value.

This has been observed in the ZFS code. Without this we can lose track of
the reference count in a zrlock object.

We should move to use the generic atomic functions, however as this has
been observed I would prefer to have this working, then move to the generic
functions.

PR:		204037
Sponsored by:	ABT Systems Ltd
2015-11-05 16:55:27 +00:00
Andriy Gapon
c34d46ff59 zfs: allow the lookup of extended attributes of an unlinked file
That's required for extattr_get_fd(2) and the like to work properly.

PR:		203201
MFC after:	17 days
2015-11-02 10:07:21 +00:00
Andriy Gapon
abc37121c4 l2arc: do not call trim_map_free() for blocks with zero b_asize
b_asize can be zero if the block is compressed into an empty block
(ZIO_COMPRESS_EMPTY) and the trim code asserts that meaningless
zero-sized trimming is not attempted.
The logic for calling trim_map_free() is extracted into a new function
l2arc_trim() to minimize code duplication.

PR:		203473
Reported by:	Willem Jan Withagen <wjw@digiware.nl>
Tested by:	Willem Jan Withagen <wjw@digiware.nl>
MFC after:	11 days
2015-10-30 12:00:34 +00:00
John Baldwin
2f99bcce1e Rename remaining linux32 symbols such as linux_sysent[] and
linux_syscallnames[] from linux_* to linux32_* to avoid conflicts with
linux64.ko.  While here, add support for linux64 binaries to systrace.
- Update NOPROTO entries in amd64/linux/syscalls.master to match the
  main table to fix systrace build.
- Add a special case for union l_semun arguments to the systrace
  generation.
- The systrace_linux32 module now only builds the systrace_linux32.ko.
  module on amd64.
- Add a new systrace_linux module that builds on both i386 and amd64.
  For i386 it builds the existing systrace_linux.ko.  For amd64 it
  builds a systrace_linux.ko for 64-bit binaries.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D3954
2015-10-22 21:28:20 +00:00
Alexander Motin
6b513e2853 MFV r289561: 6328 Fix cstyle errors in zfs codebase
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Jorgen Lundman <lundman@lundman.net>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Paul Dagnelie <pcd@delphix.com>

illumos/illumos-gate@9a686fbc18
2015-10-19 08:25:37 +00:00
Alexander Motin
62ed65eb78 MFV r289526:
5561 support root pools on EFI/GPT partitioned disks
5125 update zpool/libzfs to manage bootable whole disk pools (EFI/GPT labeled disks)

Reviewed by: Jean McCormack <jean.mccormack@nexenta.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Hans Rosenfeld <hans.rosenfeld@nexenta.com>

illumos/illumos-gate@1a902ef862

This is NOP changes for FreeBSD.
2015-10-18 18:08:33 +00:00
Alexander Motin
ab866a3d61 Fix ZFS ABI compat shims for zfs receive after r289362.
Difference appeared much less drammatic then seemed originally.
2015-10-17 07:32:46 +00:00
Alexander Motin
43f774f296 MFV r289310:
4185 add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@45818ee124

This is only a partial merge of respective ZFS infrastructure changes.
At this moment FreeBSD kernel has no those crypto algorithms, so the
parts of the code to enable them are commented out.  When they are
implemented, it will be trivial to plug them in.
2015-10-16 14:45:21 +00:00
Alexander Motin
c70e61feed MFV r289312: 2605 want to resume interrupted zfs send
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Reviewed by: Arne Jansen <sensille@gmx.net>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@9c3fd1216f

For more info, see:
 - slides http://www.slideshare.net/MatthewAhrens/openzfs-send-and-receive
 - video https://www.youtube.com/watch?v=iY44jPMvxog
 - manpage changes (for zfs resume -s and zfs send -t)
 - upcoming talk at the OpenZFS Developer Summit

The TL;DR is:
Use "zfs receive -s" to save the partially received state on failure.
On failure, get the receive token with "zfs get receive_resume_token <fs>"
Resume the send with "zfs send -t <token_value>"

Relnotes:	yes
2015-10-15 08:47:32 +00:00
Alexander Motin
3dbe12b067 MFV r289308: 6267 dn_bonus evicted too early
Reviewed by: Richard Yao <ryao@gentoo.org>
Reviewed by: Xin LI <delphij@freebsd.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Justin T. Gibbs <gibbs@FreeBSD.org>

illumos/illumos-gate@d2058105c6
2015-10-14 10:38:05 +00:00
Alexander Motin
fc6f8dee4c MFV r289306: 6295 metaslab_condense's dbgmsg should include vdev id
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andriy Gapon <avg@freebsd.org>
Reviewed by: Xin Li <delphij@freebsd.org>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Joe Stein <joe.stein@delphix.com>

illumos/illumos-gate@daec38ecb4
2015-10-14 10:31:50 +00:00
Alexander Motin
422891c28a MFV r289304: 6293 ztest failure: error == 28 (0xc == 0x1c) in ztest_tx_assign()
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@8fe00bfb87
2015-10-14 10:28:29 +00:00
Alexander Motin
95e20e65d3 MFV r289298: 6286 ZFS internal error when set large block on bootfs
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@6de9bb5603
2015-10-14 07:50:08 +00:00
Alexander Motin
a4256278bf MFV r289296: 6288 dmu_buf_will_dirty could be faster
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@0f2e7d03b8
2015-10-14 07:45:44 +00:00
Alexander Motin
0f45d37812 MFV r289294: 5219 l2arc_write_buffers() may write beyond target_sz
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov@gmail.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Steven Hartland <steven.hartland@multiplay.co.uk>
Reviewed by: Justin Gibbs <gibbs@FreeBSD.org>
Approved by: Matthew Ahrens <mahrens@delphix.com>
Author: Andriy Gapon <avg@freebsd.org>

illumos/illumos-gate@d7d9a6d919
2015-10-14 07:37:02 +00:00
Alexander Motin
2269f420b2 FreeBSD-specific addition to r289191. 2015-10-12 18:15:25 +00:00
Alexander Motin
fea4f2108f MFV r289188: 6281 prefetching should apply to 1MB reads
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Alexander Motin <mav@freebsd.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Approved by: Gordon Ross <gordon.ross@nexenta.com>
Author: George Wilson <george.wilson@delphix.com>

illumos/illumos-gate@632802744e
2015-10-12 15:48:45 +00:00
Alexander Motin
558dcd4e42 MFV r289187: 6251 add tunable to disable free_bpobj processing
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Simon Klinkert <simon.klinkert@gmail.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Albert Lee <trisk@omniti.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: George Wilson <george.wilson@delphix.com>

illumos/illumos-gate@139510fb6e
2015-10-12 15:44:44 +00:00
Alexander Motin
72b6ad9bb5 MFV r289185: 6250 zvol_dump_init() can hold txg open
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Albert Lee <trisk@omniti.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: George Wilson <george.wilson@delphix.com>

illumos/illumos-gate@b10bba7246
2015-10-12 15:39:03 +00:00
Alexander Motin
ec5a8cf7c0 Restore original array_rd_sz semantics.
Before r278702 prefetch was blocked for I/Os > 1MB, after -- >= 1MB.
1MB I/Os are used for bulk operations in CTL (XCOPY, VERIFY), and disabling
prefetch for them reduced the performance.

This is temporary local patch, that should be replaced when upstreamed.

Discussed with:	mahrens
MFC after:	3 days
2015-10-03 11:05:58 +00:00
Mark Johnston
f7c3db2537 MFV r288408:
6266 harden dtrace_difo_chunksize() with respect to malicious DIF

illumos/illumos-gate@395c7a3dcf

Reviewed by: Alex Wilson <alex.wilson@joyent.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Bryan Cantrill <bryan@joyent.com>

MFC after:	1 week
2015-09-30 05:24:22 +00:00
Andriy Gapon
a26cc6c081 sdt: static-ize couple of variables
MFC after:	11 days
2015-09-29 12:14:22 +00:00
Andriy Gapon
ab8d248801 sdt module does not seem to actually use any symbol from opensolaris module
MFC after:	11 days
2015-09-29 12:13:31 +00:00
Andriy Gapon
3bd9b9a600 std: it is important that func name is never an empty string
otherwise DTRACE_ANCHORED() returns false and that makes stack()
insert a bogus frame at the top.
For example:
dtrace -n 'test:dtrace_test::sdttest { stack(); }

This change is not really a solution, but just a work-around.
The real solution is to record the probe's call site and to use
that for resolving a function name.

PR:		195222
MFC after:	22 days
2015-09-29 12:02:23 +00:00
Andriy Gapon
09999d92b1 sdt: start checking version field when parsing probe definitions
This is an extra safety measure.

MFC after:	21 days
2015-09-29 11:58:21 +00:00
Andriy Gapon
c9d71814d5 dtrace_getarg: remove stray return statement on amd64, powerpc
MFC after:	10 days
2015-09-29 11:55:26 +00:00
Andriy Gapon
9b977fcea2 define aok in libnvpair which is linked to all zfs libraries that need aok
This removes the circular dependency of libnvpair on libzfs / libzpool.

PR:		199811
Obtained from:	bapt
MFC after:	23 days
2015-09-28 15:25:36 +00:00
Xin LI
8012d6910c MFV r288063: make dataset property de-registration operation O(1)
A change to a property on a dataset must be propagated to its descendants
in case that property is inherited. For datasets whose information is
not currently loaded into memory (e.g. a snapshot that isn't currently
mounted), there is nothing to do; the property change will take effect
the next time that dataset is loaded. To handle updates to datasets that
are in-core, ZFS registers a callback entry for each property of each
loaded dataset with the dsl directory that holds that dataset. There
is a dsl directory associated with each live dataset that references
both the live dataset and any snapshots of the live dataset. A property
change is effected by doing a traversal of the tree of dsl directories
for a pool, starting at the directory sourcing the change, and invoking
these callbacks.

The current implementation both registers and de-registers properties
individually for each loaded dataset. While registration for a property is
O(1) (insert into a list), de-registration is O(n) (search list and then
remove). The 'n' for de-registration, however, is not limited to the size
(number of snapshots + 1) of the dsl directory. The eviction portion
of the life cycle for the in core state of datasets is asynchronous,
which allows multiple copies of the dataset information to be in-core
at once. Only one of these copies is active at any time with the rest
going through tear down processing, but all copies contribute to the
cost of performing a dsl_prop_unregister().

One way to create multiple, in-flight copies of dataset information
is by performing "zfs list" operations from multiple threads
concurrently. In-core dataset information is loaded on demand and then
evicted when reference counts drops to zero. For datasets that are not
mounted, there is no persistent reference count to keep them resident.
So, a list operation will load them, compute the information required to
do the list operation, and then evict them. When performing this operation
from multiple threads it is possible that some of the in-core dataset
information will be reused, but also possible to lose the race and load
the dataset again, even while the same information is being torn down.

Compounding the performance issue further is a change made for illumos
issue 5056 which made dataset eviction single threaded. In environments
using automation to manage ZFS datasets, it is now possible to create
enough of a backlog of dataset evictions to consume excessive amounts
of kernel memory and to bog down the system.

The fix employed here is to make property de-registration O(1). With this
change in place, it is hoped that a single thread is more than sufficient
to handle eviction processing. If it isn't, the problem can be solved
by increasing the number of threads devoted to the eviction taskq.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dir.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dataset.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dir.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_prop.h:
    Associate dsl property callback records with both the
    dsl directory and the dsl dataset that is registering the
    callback. Both connections are protected by the dsl directory's
    "dd_lock".

    When linking callbacks into a dsl directory, group them by
    the property type. This helps reduce the space penalty for the
    double association (the property name pointer is stored once
    per dsl_dir instead of in each record) and reduces the number of
    strcmp() calls required to do callback processing when updating
    a single property. Property types are stored in a linked list
    since currently ZFS registers a maximum of 10 property types
    for each dataset.

    Note that the property buckets/records associated with a dsl
    directory are created on demand, but only freed when the dsl
    directory is freed. Given the static nature of property types
    and their small number, there is no benefit to freeing the few
    bytes of memory used to represent the property record earlier.
    When a property record becomes empty, the dsl directory is either
    going to become unreferenced a little later in this thread of
    execution, or there is a high chance that another dataset is
    going to be loaded that would recreate the bucket anyway.

    Replace dsl_prop_unregister() with dsl_prop_unregister_all().
    All callers of dsl_prop_unregister() are trying to remove
    all property registrations for a given dsl dataset anyway. By
    changing the API, we can avoid doing any lookups of callbacks
    by property type and just traverse the list of all callbacks
    for the dataset and free each one.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:
    Replace use of dsl_prop_unregister() with the new
    dsl_prop_unregister_all() API.

illumos/illumos-gate@03bad06fbb
    Author: Justin Gibbs <gibbs@scsiguy.com>
    Reviewed by: Matthew Ahrens <mahrens@delphix.com>
    Reviewed by: Prakash Surya <prakash.surya@delphix.com>
    Approved by: Dan McDonald <danmcd@omniti.com>

Illumos issue:
    6171 dsl_prop_unregister() slows down dataset eviction
    https://www.illumos.org/issues/6171

MFC after:	2 weeks
2015-09-25 01:05:44 +00:00