3557 dumpvp_size is not updated correctly when a dump zvol's size is changed
3558 setting the volsize on a dump device does not return back ENOSPC
3559 setting a volsize larger than the space available sometimes succeeds
3560 dumpadm should be able to remove a dump device
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Albert Lee <trisk@nexenta.com>
References:
https://www.illumos.org/issues/3559https://github.com/illumos/illumos-gate/commit/c61ea56
Porting notes:
- Internal zvol.c changes not applied due to implementation differences.
The external interface and behavior was already consistent with the
latest upstream code.
- Retired 2.6.28 HAVE_CHECK_DISK_SIZE_CHANGE configure check. All
supported kernels (2.6.32 and newer) provide this interface.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4217
While stack size will vary by architecture it has historically defaulted to
8K on x86_64 systems. However, as of Linux 3.15 the default thread stack
size was increased to 16K. These kernels are now the default in most non-
enterprise distributions which means we no longer need to assume 8K stacks.
This patch takes advantage of that fact by appropriately reverting stack
conservation changes which were made to ensure stability. Changes which
may have had a negative impact on performance for certain workloads. This
also has the side effect of bringing the code slightly more in line with
upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#4059
The xattr_hander->{list,get,set} were changed to take a xattr_handler,
and handler_flags argument was removed and should be accessed by
handler->flags.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4021
As part of block polling support in Linux 4.4, make_request_fn should
return a cookie value of type blk_qc_t. For now, we make zvol_request
always return BLK_QC_T_NONE until we assess whether and how we want
to support block polling.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4021
Commit b39c22b set the READ_SYNC and WRITE_SYNC flags for a bio
based on the ZIO_PRIORITY_* flag passed in. This had the unnoticed
side-effect of making the vdev_disk_io_start() synchronous for
certain I/Os.
This in turn resulted in vdev_disk_io_start() being able to
re-dispatch zio's which would result in a RCU stalls when a disk
was removed from the system. Additionally, this could negatively
impact performance and explains the performance regressions reported
in both #3829 and #3780.
This patch resolves the issue by making the blocking behavior
dependent on a 'wait' flag being passed rather than overloading
the passed bio flags.
Finally, the WRITE_SYNC and READ_SYNC behavior is restricted to
non-rotational devices where there is no benefit to queuing to
aggregate the I/O.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3652
Issue #3780
Issue #3785
Issue #3817
Issue #3821
Issue #3829
Issue #3832
Issue #3870
Commit torvalds/linux@4246a0b63b
("block: add a bi_error field to struct bio") dropped the error
argument from bio_endio in favor of newly introduced bio->bi_error.
This also replaces bio->bi_flags value BIO_UPTODATE.
bio_endio was a 3 argument function until Linux 2.6.24, which made it
a 2 argument function, and now the prototype has changed yet again to
a 1 argument function. Support for pre 2.6.24 kernels was already
dropped with 37f9dac592 ("zvol processing should use struct bio")
which assumed the 2 argument version in zvol_request(). Remaining code
to support the 3 argument version is hereby removed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Issue #3799
zfsonlinux/zfs@e20cd6f7a8 caused us to
lose IO accounting on zvols. When I originally wrote that last year, the
symbols we needed to maintain IO accounting were GPL exported, but
torvalds/linux@394ffa503b provided
suitable symbols for restoring this functionality 4 months later. We
can call them to restore the IO accounting on Linux 3.19 and later as
well as any older kernels where that patch is backported.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3741
This autotools check was never needed because we can check for the
existence of QUEUE_FLAG_NONROT in the kernel headers.
Also, the comment in config/kernel-blk-queue-nonrot.m4 is incorrect.
This was a Linux 2.6.28 API change, not a Linux 2.6.27 API change.
Signed-off-by: Richard Yao <ryao@gentoo.org>
This autotools check was never needed because we can check for the
existence of QUEUE_FLAG_DISCARD in the kernel headers.
Signed-off-by: Richard Yao <ryao@gentoo.org>
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>
This is needed for supporting kernels earlier than 2.6.30. Support for
those kernels was dropped, so we can safely remove this check.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This is needed for supporting kernels earlier than 2.6.30. Support for
those kernels was dropped, so we can safely remove this check.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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
Starting from linux-2.6.37, {kmap,kunmap}_atomic takes 1 argument instead of 2.
We use zfs_{kmap,kunmap}_atomic as wrappers and always take 2 argument, but
ignore the 2nd for newer kernel.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Pull struct backing_dev_info off the stack: by linux-4.1 it's grown
past our 1024 byte stack frame warning limit resulting in an incorrect
configure result.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes#3671
This is some minor fixes to commits 2cac7f5f11
and 2a34db1bdb.
* Make sure to alien'ate the new initramfs rpm package as well!
The rpm package is build correctly, but alien isn't run on it to
create the deb.
* Before copying file from COPY_FILE_LIST, make sure the DESTDIR/dir exists.
* Include /lib/udev/vdev_id file in the initrd.
* Because the initrd needs to use '/sbin/modprobe' instead of 'modprobe',
we need to use this in load_module() as well.
* Make sure that load_module() can be used more globaly, instead of
calling '/sbin/modprobe' all over the place.
* Make sure that check_module_loaded() have a parameter - module to
check.
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3626
Build products from an out of tree build should be written
relative to the build directory. Sources should be referred
to by their locations in the source directory.
This is accomplished by adding the 'src' and 'obj' variables
for the module Makefile.am, using relative paths to reference
source files, and by setting VPATH when source files are not
co-located with the Makefile. This enables the following:
$ mkdir build
$ cd build
$ ../configure \
--with-spl=$HOME/src/git/spl/ \
--with-spl-obj=$HOME/src/git/spl/build
$ make -s
This change also has the advantage of resolving the following
warning which is generated by modern versions of automake.
Makefile.am:00: warning: source file 'xxx' is in a subdirectory,
Makefile.am:00: but option 'subdir-objects' is disabled
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1082
As of Linux 4.2 the kernel has completely retired the nameidata
structure. One of the few remaining consumers of this interface
were the follow_link() and put_link() callbacks.
This patch adds the required checks to configure to detect the
interface change and updates the functions accordingly. Migrating
to the simple_follow_link() interface was considered but was decided
against ironically due to the increased complexity.
It also should be noted that the kernel follow_link() and put_link()
interfaces changes several times after 4.1 and but before 4.2. This
means there is a narrow range of kernel commits which never appear
in an official tag of the Linux kernel which ZoL will not build.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Issue #3596
As of gcc version 5.1.1 a new boolean comparison warning has been
introduced. This warning is harmless but is triggered several places
in the ZFS code base. Because warnings are promoted to errors when
building with debugging enabled it is necessary to disable the warning
when using versions of gcc which automatically enabling this check.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
* Supports booting of a ZFS snapshot.
Do this by cloning the snapshot into a dataset. If this, the resulting
dataset, already exists, destroy it. Then mount it on root.
* If snapshot does not exist, use base dataset (the part before '@')
as boot filesystem instead.
* If no snapshot is specified on the 'root=' kernel command line, but there
is an '@', then get a list of snapshots below that filesystem and ask the
user which to use.
* Clone with 'mountpoint=none' and 'canmount=noauto' - we mount manually
and explicitly.
* For sub-filesystems, that doesn't have a mountpoint property set, we use
the 'org.zol:mountpoint' to keep track of it's mountpoint.
* Allow rollback of snapshots instead of clone it and boot from the clone.
* Allow mounting a root- and subfs with mountpoint=legacy set
* Allow mounting a filesystem which is using nativ encryption.
* Support all currently used kernel command line arguments
All the different distributions have their own standard on what to specify
on the kernel command line to boot of a ZFS filesystem.
* Extra options:
* zfsdebug=(on,yes,1) Show extra debugging information
* zfsforce=(on,yes,1) Force import the pool
* rollback=(on,yes,1) Rollback (instead of clone) the snapshot
* Only try to import pool if it haven't already been imported
* This will negate the need to force import a pool that have not been exported cleanly.
* Support exclusion of pools to import by setting ZFS_POOL_EXCEPTIONS in /etc/default/zfs.
* Support additional configuration variable ZFS_INITRD_ADDITIONAL_DATASETS
to mount additional filesystems not located under your root dataset.
* Include /etc/modprobe.d/{zfs,spl}.conf in the initrd if it/they exist.
* Include the udev rule to use by-vdev for pool imports.
* Include the /etc/default/zfs file to the initrd.
* Only try /dev/disk/by-* in the initrd if USE_DISK_BY_ID is set.
* Use /dev/disk/by-vdev before anything.
* Add /dev as a last ditch attempt.
* Fallback to using the cache file if that exist if nothing else worked.
* Use /sbin/modprobe instead of built-in (BusyBox) modprobe.
This gets rid of the message "modprobe: can't load module zcommon".
Thanx to pcoultha for finding this.
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2116Closes#2114
For kernels which do not implement a per-suberblock shrinker,
those older than Linux 3.1, the shrink_dcache_parent() function
was used to attempt to reclaim dentries. This was found not be
entirely reliable and could lead to performance issues on older
kernels running meta-data heavy workloads.
To address this issue a zfs_sb_prune_aliases() function has been
added to implement this functionality. It relies on traversing
the list of znodes for a filesystem and adding them to a private
list with a reference held. The private list can then be safely
walked outside the z_znodes_lock to prune dentires and drop the
last reference so the inode can be freed.
This provides the same synchronous behavior as the per-filesystem
shrinker and has the advantage of depending on only long standing
interfaces.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3501
Linux 3.15 commit torvalds/linux@293bc98 introduced two new methods.
The ->read_iter() and ->write_iter() methods were designed to replace
the ->aio_read() and ->aio_write() interfaces. Both interfaces were
preserved for several kernel releases in order to migrate all existing
consumers to the new interfaces. But as of Linux 4.1 the legacy
interface has been retired and the ZFS code must be updated to use
the new interfaces.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3352
Kernels >= 3.12 have a NUMA-aware superblock shrinker which is used in
ZoL by zfs_sb_prune(). This patch calls the shrinker for each on-line
NUMA node in order that memory be freed for each one.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3495
* Based on the init scripts included with Debian GNU/Linux, then take code
from the already existing ones, trying to merge them into one set of
scripts that will work for 'everyone' for better maintainability.
* Add configurable variables to control the workings of the init scripts:
* ZFS_INITRD_PRE_MOUNTROOT_SLEEP
Set a sleep time before we load the module (used primarily by initrd
scripts to allow for slower media (such as USB devices etc) to be
availible before we load the zfs module).
* ZFS_INITRD_POST_MODPROBE_SLEEP
Set a timed sleep in the initrd to after the load of the zfs module.
* ZFS_INITRD_ADDITIONAL_DATASETS
To allow for mounting additional datasets in the initrd. Primarily used
in initrd scripts to allow for when filesystem needed to boot (such as
/usr, /opt, /var etc) isn't directly under the root dataset.
* ZFS_POOL_EXCEPTIONS
Exclude pools from being imported (in the initrd and/or init scripts).
* ZFS_DKMS_ENABLE_DEBUG, ZFS_DKMS_ENABLE_DEBUG_DMU_TX, ZFS_DKMS_DISABLE_STRIP
Set to control how dkms should build the dkms packages.
* ZPOOL_IMPORT_PATH
Set path(s) where "zpool import" should import pools from.
This was previously the job of "USE_DISK_BY_ID" (which is still used
for backwards compatibility) but was renamed to allow for better
control of import path(s).
* If old USE_DISK_BY_ID is set, but not new ZPOOL_IMPORT_PATH, then we
set ZPOOL_IMPORT_PATH to sane defaults just to be on the safe side.
* ZED_ARGS
To allow for local options to zed without having to change the init script.
* The import function, do_import(), imports pools by name instead of '-a'
for better control of pools to import and from where.
* If USE_DISK_BY_ID is set (for backwards compatibility), but isn't 'yes'
then ignore it.
* If pool(s) isn't found with a simple "zpool import" (seen it happen),
try looking for them in /dev/disk/by-id (if it exists). Any duplicates
(pools found with both commands) is filtered out.
* IF we have found extra pool(s) this way, we must force USE_DISK_BY_ID
so that the first, simple "zpool import $pool" is able to find it.
* Fallback on importing the pool using the cache file (if it exists) only
if 'simple' import (either with ZPOOL_IMPORT_PATH or the 'built in'
defaults) didn't work.
* The export function, do_export(), will export all pools imported, EXCEPT
the root pool (if there is one).
* ZED script from the Debian GNU/Linux packages added.
* Refreshed ZED init script from behlendorf@5e7a660 to be portable so it
may be used on both LSB and Redhat style systems.
* If there is no pool(s) imported and zed successfully shut down, we will
unload the zfs modules.
* The function library file for the ZoL init script is installed as
/etc/init.d/zfs-functions.
* The four init scripts, the /etc/{defaults,sysconfig,conf.d}/zfs config file
as well as the common function library is tagged as '%config(noreplace)' in
the rpm rules file to make sure they are not replaced automatically if locally
modifed.
* Pitfals and workarounds:
* If we're running from init, remove stale /etc/dfs/sharetab before importing
pools in the zfs-import init script.
* On Debian GNU/Linux, there's a 'sendsigs' script that will kill basically
everything quite early in the shutdown phase and zed is/should be stopped
much later than that. We don't want zed to be among the ones killed, so add
the zed pid to list of pids for 'sendsigs' to ignore.
* CentOS uses echo_success() and echo_failure() to print out status of
command. These in turn uses "echo -n \0xx[etc]" to move cursor and choose
colour etc. This doesn't work with the modified IFS variable we need to
use in zfs-import for some reason, so work around that when we define
zfs_log_{end,failure}_msg() for RedHat and derivative distributions.
* All scripts passes ShellCheck (with one false positive in do_mount()).
Signed-off-by: Turbo Fredriksson turbo@bayour.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Richard Yao <ryao@gentoo.org>
Reviewed by: Chris Dunlap <cdunlap@llnl.gov>
Closes#2974Closes#2107
Commit 60e9f69 added the --with-mounthelperdir option for Gentoo
and in the process accidentally modified the default installation
location. For security reasons mount(8) expects it to only be
installed under /sbin.
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3426
Commit f4af6bb783 which added support
for REQ_FAILFAST_MASK but the new autoconf test didn't use the same
preprocessor macro name as the code did.
The effect is that FAILFAST mode has not been enabled for ZoL in any
post-2.6.35 kernel.
Retire the HAVE_BIO_RW_FAILFAST interface used in pre-2.6.28 kernels.
Raise an error condition if the FAILFAST interface can't be detected.
Signed-off-by: Tim Chase <tim@onlight.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3386
Provide a Redhat specific zfs-kmod.spec file which uses the old style
kmods (not kmods2) packaging. By using the provided kmodtool script
packages can be built which support weak modules. This allows for the
kernel to be updated without having to rebuild the ZFS kernel modules.
Packages for RHEL/Centos/SL/TOSS which use this spec file can by built
as follows:
$ ./configure --with-spec=redhat
$ make rpms
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Originally it was thought that custom spec files might be required
for Fedora. Happily that has turns out not to be the case. Since
this directory just contains symlinks to the generic spec files it
can be removed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Explicitly disable the unused by variable warnings by setting
__attribute__((unused)) for bdi_setup_and_register(). This is
required because the function is defined with the __must_check
attribute.
Signed-off-by: Bill McGonigle <bill-github.com-public1@bfccomputing.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3141
The 'capabilities' argument which was passed to bdi_setup_and_register()
has been removed. File systems should no longer pass BDI_CAP_MAP_COPY.
For our purposes this means there are now three different interfaces
which must be handled. A zpl_bdi_setup_and_register() wrapper function
has been introduced to provide a single interface to the ZPL code.
* 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
* 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
* 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
I've also taken this opportunity to remove HAVE_BDI because kernels
older then 2.6.32 are no longer supported. All kernels newer than
this will have one of the above interfaces.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes#3128
struct access f->f_dentry->d_inode was replaced by accessor function
file_inode(f)
Signed-off-by: Joerg Thalheim <joerg@higgsboson.tk>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3084
Using AC_LANG_SOURCE with some versions of autoconf is problematic if
the given source is to be written to a header file. Such versions assume
the contents are to be written to conftest.c and generate shell code to
that effect. The contents of the test program to detect support for
Linux tracepoints were consequently malformed (containing the source for
conftest.h) so the build system incorrectly disabled tracepoints
support. Fix this in ZFS_LINUX_TRY_COMPILE_HEADER by passing the header
source directly to ZFS_LINUX_COMPILE_IFELSE.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2953
This patch leverages Linux tracepoints from within the ZFS on Linux
code base. It also refactors the debug code to bring it back in sync
with Illumos.
The information exported via tracepoints can be used for a variety of
reasons (e.g. debugging, tuning, general exploration/understanding,
etc). It is advantageous to use Linux tracepoints as the mechanism to
export this kind of information (as opposed to something else) for a
number of reasons:
* A number of external tools can make use of our tracepoints
"automatically" (e.g. perf, systemtap)
* Tracepoints are designed to be extremely cheap when disabled
* It's one of the "accepted" ways to export this kind of
information; many other kernel subsystems use tracepoints too.
Unfortunately, though, there are a few caveats as well:
* Linux tracepoints appear to only be available to GPL licensed
modules due to the way certain kernel functions are exported.
Thus, to actually make use of the tracepoints introduced by this
patch, one might have to patch and re-compile the kernel;
exporting the necessary functions to non-GPL modules.
* Prior to upstream kernel version v3.14-rc6-30-g66cc69e, Linux
tracepoints are not available for unsigned kernel modules
(tracepoints will get disabled due to the module's 'F' taint).
Thus, one either has to sign the zfs kernel module prior to
loading it, or use a kernel versioned v3.14-rc6-30-g66cc69e or
newer.
Assuming the above two requirements are satisfied, lets look at an
example of how this patch can be used and what information it exposes
(all commands run as 'root'):
# list all zfs tracepoints available
$ ls /sys/kernel/debug/tracing/events/zfs
enable filter zfs_arc__delete
zfs_arc__evict zfs_arc__hit zfs_arc__miss
zfs_l2arc__evict zfs_l2arc__hit zfs_l2arc__iodone
zfs_l2arc__miss zfs_l2arc__read zfs_l2arc__write
zfs_new_state__mfu zfs_new_state__mru
# enable all zfs tracepoints, clear the tracepoint ring buffer
$ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
$ echo 0 > /sys/kernel/debug/tracing/trace
# import zpool called 'tank', inspect tracepoint data (each line was
# truncated, they're too long for a commit message otherwise)
$ zpool import tank
$ cat /sys/kernel/debug/tracing/trace | head -n35
# tracer: nop
#
# entries-in-buffer/entries-written: 1219/1219 #P:8
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss: hdr...
z_rd_int/0-30156 [003] .... 91344.200611: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.201173: zfs_arc__miss: hdr...
z_rd_int/1-30157 [003] .... 91344.201756: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.201795: zfs_arc__miss: hdr...
z_rd_int/2-30158 [003] .... 91344.202099: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202126: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202130: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202134: zfs_arc__hit: hdr ...
lt-zpool-30132 [003] .... 91344.202146: zfs_arc__miss: hdr...
z_rd_int/3-30159 [003] .... 91344.202457: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202484: zfs_arc__miss: hdr...
z_rd_int/4-30160 [003] .... 91344.202866: zfs_new_state__mru...
lt-zpool-30132 [003] .... 91344.202891: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.203034: zfs_arc__miss: hdr...
z_rd_iss/1-30149 [001] .... 91344.203749: zfs_new_state__mru...
lt-zpool-30132 [001] .... 91344.203789: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.203878: zfs_arc__miss: hdr...
z_rd_iss/3-30151 [001] .... 91344.204315: zfs_new_state__mru...
lt-zpool-30132 [001] .... 91344.204332: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204337: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204352: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204356: zfs_arc__hit: hdr ...
lt-zpool-30132 [001] .... 91344.204360: zfs_arc__hit: hdr ...
To highlight the kind of detailed information that is being exported
using this infrastructure, I've taken the first tracepoint line from the
output above and reformatted it such that it fits in 80 columns:
lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss:
hdr {
dva 0x1:0x40082
birth 15491
cksum0 0x163edbff3a
flags 0x640
datacnt 1
type 1
size 2048
spa 3133524293419867460
state_type 0
access 0
mru_hits 0
mru_ghost_hits 0
mfu_hits 0
mfu_ghost_hits 0
l2_hits 0
refcount 1
} bp {
dva0 0x1:0x40082
dva1 0x1:0x3000e5
dva2 0x1:0x5a006e
cksum 0x163edbff3a:0x75af30b3dd6:0x1499263ff5f2b:0x288bd118815e00
lsize 2048
} zb {
objset 0
object 0
level -1
blkid 0
}
For the specific tracepoint shown here, 'zfs_arc__miss', data is
exported detailing the arc_buf_hdr_t (hdr), blkptr_t (bp), and
zbookmark_t (zb) that caused the ARC miss (down to the exact DVA!).
This kind of precise and detailed information can be extremely valuable
when trying to answer certain kinds of questions.
For anybody unfamiliar but looking to build on this, I found the XFS
source code along with the following three web links to be extremely
helpful:
* http://lwn.net/Articles/379903/
* http://lwn.net/Articles/381064/
* http://lwn.net/Articles/383362/
I should also node the more "boring" aspects of this patch:
* The ZFS_LINUX_COMPILE_IFELSE autoconf macro was modified to
support a sixth paramter. This parameter is used to populate the
contents of the new conftest.h file. If no sixth parameter is
provided, conftest.h will be empty.
* The ZFS_LINUX_TRY_COMPILE_HEADER autoconf macro was introduced.
This macro is nearly identical to the ZFS_LINUX_TRY_COMPILE macro,
except it has support for a fifth option that is then passed as
the sixth parameter to ZFS_LINUX_COMPILE_IFELSE.
These autoconf changes were needed to test the availability of the Linux
tracepoint macros. Due to the odd nature of the Linux tracepoint macro
API, a separate ".h" must be created (the path and filename is used
internally by the kernel's define_trace.h file).
* The HAVE_DECLARE_EVENT_CLASS autoconf macro was introduced. This
is to determine if we can safely enable the Linux tracepoint
functionality. We need to selectively disable the tracepoint code
due to the kernel exporting certain functions as GPL only. Without
this check, the build process will fail at link time.
In addition, the SET_ERROR macro was modified into a tracepoint as well.
To do this, the 'sdt.h' file was moved into the 'include/sys' directory
and now contains a userspace portion and a kernel space portion. The
dprintf and zfs_dbgmsg* interfaces are now implemented as tracepoint as
well.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This file may be added by automake and therefore should be added
to config/.gitignore. For the full list of possible auxiliary
programs see the full automake documentation.
http://www.gnu.org/software/automake/manual/automake.html#Auxiliary-Programs
Signed-off-by: Marcel Wysocki <maci.stgn@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2848
Installing outside of the prefix is not permissible under Gentoo Prefix.
The package manager will cause the installation process to fail if/when
it sees this. We could handle this by disabling systemd support on
prefix because systemd does not check these paths, but the Gentoo
Council decided that small files such as these should be installed.
That means disabling systemd support on prefix is not an acceptable
workaround. As a consequence, we need some way of control the directory
into which these files are installed.
Making this configurable increases our compliance with the
freedesktop.org specification, which allows these files to be installed
into /etc/modules-load.d:
http://www.freedesktop.org/software/systemd/man/modules-load.d.html
Signed-off-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2641
Installing outside of the prefix is not permissible under Gentoo Prefix.
The package manager will cause the installation process to fail if/when
it sees this. I could script a workaround inside the ebuild, but it
seemed to make more sense to make this more configurable.
Signed-off-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2641
Since we changed the default location for the kernel headers to respect
--prefix in the SPL, we must search that location to prevent user builds
from breaking.
Signed-off-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2641
Apply the license specified in the META file to ensure the
compatibility checks are all performed consistently.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2757
The HAVE_IOCTL_* configure checks were originally added for
compatibility with an ancient version of glibc. This support
and additional complexity is no longer needed and is therefore
being removed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Closes#585
There are two common locations where udev and dracut components are
commonly installed. When building packages using the 'make rpm|deb'
targets check those common locations and pass them to rpmbuild. For
non-standard configurations these values can be provided by the
the following configure options:
--with-udevdir=DIR install udev helpers [default=check]
--with-udevruledir=DIR install udev rules [[UDEVDIR/rules.d]]
--with-dracutdir=DIR install dracut helpers [default=check]
When rebuilding using the source packages the per-distribution
default values specified in the spec file will be used. This is
the preferred way to build packages for a distribution but the
ability to override the defaults is provided as a convenience.
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2310Closes#1680
Set LANG=C before calling 'rpmbuild' to avoid rpmbuild failing on
the translated date string in the changelog.
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: zfsonlinux/spl#306
George Wilson
Kamil Domański
Brian Behlendorf
Chunwei Chen
Lukas Wunner
Richard Yao
Chunwei Chen
Chris Dunlop
Turbo Fredriksson
Matus Kral
Tim Chase
Tim Chase
Bill McGonigle
Jörg Thalheim
Ned Bass
Prakash Surya
Marcel Wysocki
Richard Yao