This patch is based on the previous work done by @andrey-ve and
@yshui. It triggers the automount by using kern_path() to traverse
to the known snapshout mount point. Once the snapshot is mounted
NFS can access the contents of the snapshot.
Allowing NFS clients to access to the .zfs/snapshot directory would
normally mean that a root user on a client mounting an export with
'no_root_squash' would be able to use mkdir/rmdir/mv to manipulate
snapshots on the server. To prevent configuration mistakes a
zfs_admin_snapshot module option was added which disables the
mkdir/rmdir/mv functionally. System administators desiring this
functionally must explicitly enable it.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2797Closes#1655Closes#616
Prevents NFS client from detection of different fileids of snapshot root dentry
before & after snapshot mount.
Signed-off-by: Andrey Vesnovaty <andrey.vesnovaty@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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>
Linux 2.6.36 introduced REQ_SECURE to indicate when discards *must* be
processed, such that we cannot do optimizations like block alignment.
Consequently, the discard semantics prior to 2.6.36 require us to always
process unaligned discards. Previously, we would do this optimization
regardless. This patch changes things to correctly restrict this
optimization to situations where REQ_SECURE exists, but is not included
in the flags.
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>
Reclaim in the traverse prefetch thread, which is run on the system
taskq, can overrun the stack.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes#3733
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
Pre-2.6.37 kernels support REQ_FUA in request flags, but not in BIO
flags. zvols are the only consumer of VDEV_REQ_FUA and since they are
passed requests, they should be obey the REQ_FUA flag like later
kernels. This optimization will only matter on 2.6.36 and 2.6.37 because
the zvol rework changes things to use bio, where we no longer are able
to distinguish on earlier kernels
Signed-off-by: Richard Yao <ryao@gentoo.org>
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
Allow for easy turning of a pools reserved free space. Previous
versions of ZFS (v0.6.4 and earlier) held 1/64 of the pools capacity
in reserve. Commits 3d45fdd and 0c60cc3 increased this to 1/32.
Setting spa_slop_shift=6 will restore the previous default setting.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3724
ZED depends on /var. When /var is a separate dataset, it must be
mounted before starting ZED. This change moves the zfs-zed service
from starting first, to starting after zfs-mount, but before zfs-share.
As discussed in issue #3513, ZED does not need to start first in order
to consume events made during the zfs-import and zfs-mount services.
The events will be queued and can be handled later in the boot process.
ZED may, however, handle sharing in the future, so it should be started
before the zfs-share service.
This commit also stops the zfs-import service from writing temp files
to /var/tmp on shutdown and it corrects the return code for the OpenRC
service.
Other OpenRC-specific changes noted in issue #3513 were reitereated in
issue #3715 and committed in da619f3.
Signed-off-by: James Lee <jlee@thestaticvoid.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3513
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
Before read locking z_teardown_inactive_lock, we need to check if we have
already had write lock on it. Otherwise, we would deadlock on ourself when
doing rollback:
zfs_ioc_rollback
->zfs_suspend_fs (z_teardown_inactive_lock, RW_WRITER)
->zfs_resume_fs->zfs_rezget->zfs_iput_async->iput-> ...
->zfs_inactive (z_teardown_inactive_lock, RW_READER)
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2869
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>
The misc_deregister() function was changed to a void return type.
Rather than add compatibility code to detect this change simply
ignore the return code on all kernels. It was only used to log
an informational error message of no real value.
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
There's no metadata to write to disk for ctldir inodes. So we check if
a inode belongs to the ctldir in zpl_commit_metadata, and returns
immediately if it is.
Signed-off-by: Andrey Vesnovaty <andrey.vesnovaty@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2797
zvols should not be an entropy source for the kernel. Disable it to be
consistent with the upstream kernel.
torvalds/linux@b277da0a8a
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3713
Add a missing space to the zfs_vdev_sync_write_min_active module
parameter description.
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3714
The dependencies for handling / on ZFS belong in the mount script, not
the zed script.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3715
As part of the stack reduction effort in
50b25b2187, a zio_t containing a taskq_ent
was added to struct vdev_queue which itself is part of struct vdev.
The taskq entry should be initialized as is currently done in zio_create()
for newly-created bare zio_t object. The rationale is the same as is
described in f467b05a26.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3709
Add new keyword 'slot' to vdev_id.conf
This selects from where to get the slot number for a SAS/SATA disk
Needed to enable access to the physical position of a disk in a
Supermicro 2027R-AR24NV .
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes#3693
If the ZAP object containing a snapshot map is corrupted due to an
unrecoverable checksum error or otherwise, dsl_dataset_name() will
normally panic the system due to its VERIFY.
This patch attempts to allow a recovery avenue from such situations by
manufacturing a descriptive snapshot name and then ignoring the error.
Scrubbing a pool with this type of corruption will then show the affected
object in the error list rather than panicking.
The recovery code is only enabled when the zfs_recover module parameter
is set.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3705
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
When support for large blocks was added DMU_MAX_ACCESS was increased
to allow for blocks of up to 16M to fit in a transaction handle.
This had the side effect of increasing the max_hw_sectors_kb for
volumes, which are scaled off DMU_MAX_ACCESS, to 64M from 10M.
This is an issue for volumes which by default use an 8K block size
because it results in dmu_buf_hold_array_by_dnode() allocating a
64K array for the dbufs. The solution is to restore the maximum
size to ~10M. This patch specifically changes it to 16M which is
close enough.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3684
Starting from Linux 4.1 allows iov_iter with bio_vec to be passed into
iter_read/iter_write. Notably, the loop device will pass bio_vec to backend
filesystem. However, current ZFS code assumes iovec without any check, so it
will always crash when using loop device.
With the restructured uio_t, we can safely pass bio_vec in uio_t with UIO_BVEC
set. The uio* functions are modified to handle bio_vec case separately.
The const uio_iov causes some warning in xuio related stuff, so explicit
convert them to non const.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3511Closes#3640
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>
The spa_config_write() function relies on the classic method of
making sure updates to the /etc/zfs/zpool.cache file are atomic.
It writes out a temporary version of the file and then uses
vn_rename() to switch it in to place. This way there can never
exist a partial version of the file, it's all or nothing.
Conceptually this is a good strategy and it makes good sense
for platforms where it's easy to do a rename within the kernel.
Unfortunately, Linux is not one of those platforms. Even doing
basic I/O to a file system from within the kernel is strongly
discouraged. In order to support this at all the vn_rename()
implementation ends up being complex and fragile. So fragile
that recent Linux 4.2 changes have broken it.
While it is possible to update vn_rename() to work with the
latest kernels a better long term strategy is to stop using
vn_rename() entirely. Then all this complex, fragile code can
be removed. Achieving this is straight forward because
config_write() is the only consumer of vn_rename().
This patch reworks spa_config_write() to update the cache file
in place. The file will be truncated, written out, and then
synced to disk. If an error is encountered the file will be
unlinked leaving the system in a consistent state.
This does expose a tiny tiny tiny window where a system could
crash at exactly the wrong moment could leave a partially written
cache file. However, this is highly unlikely because the cache
file is 1) infrequently updated, 2) only a few kilobytes in size,
and 3) written with a single vn_rdwr() call.
If this were to somehow happen it poses no risk to pool. Simply
removing the cache file will allow the pool to be imported cleanly.
Going forward this will be even less of an issue as we intend to
disable the use of a cache file by default.
Bottom line not using vn_rename() allows us to make ZoL more
robust against upstream kernel changes.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3653
Failing to lookup a name in the spa_ddt_stat_object should not result
in a panic in ddt_object_load(). The error can be safely returned to
the caller for handling resulting in a useful user error message.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3370
The zpool create subcomand should not return an error on debug builds of
the userland tools when given zvols.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3595
Without the parenthesis, this particular ASSERT will evaluate to
"(RW_READER == (!zap->zap_ismicro && fatreader)) ? RW_READER : lti"
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3685
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
At verbosity levels of 6 or greater, ztest_dsl_prop_set_uint64() attempts
to display the value of all properties as indexed values regardless of
whether the property is an indexed value or simply an un-indexed integer.
This patch causes the numeric value of the property to be displayed if
zfs_prop_index_to_string() fails.
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3649
This commit reworks the zed_notify_email() function to allow
configuration of the mail executable and command-line arguments.
ZED_EMAIL_PROG specifies the name or path of the executable responsible
for sending notifications via email. This variable defaults to "mail".
ZED_EMAIL_OPTS specifies command-line options passed to ZED_EMAIL_PROG.
The following keyword substitutions are performed:
- @ADDRESS@ is replaced with the recipient email address(es)
- @SUBJECT@ is replaced with the notification subject
This variable defaults to "-s '@SUBJECT@' @ADDRESS@".
ZED_EMAIL_ADDR replaces ZED_EMAIL (although the latter is retained
for backward compatibility). This variable can contain multiple
addresses as long as they are delimited by whitespace.
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3634Closes#3631
This commit fixes the two adjacent spaces that appear in zed_log_err()
messages when ZEVENT_EID is undefined.
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This brings the behavior of arc_memory_throttle() back in sync with
illumos. The updated memory throttling policy roughly goes like this:
* Never throttle if more than 10% of memory is free. This threshold
is configurable with the zfs_arc_lotsfree_percent module option.
* Minimize any throttling of kswapd even when free memory is below
the set threshold. Allow it to write out pages as quickly as
possible to help alleviate the memory pressure.
* Delay all other threads when free memory is below the set threshold
in order to avoid compounding the memory pressure. Buffers will be
evicted from the ARC to reduce the issue.
The Linux specific zfs_arc_memory_throttle_disable module option has
been removed in favor of the existing zfs_arc_lotsfree_percent tuning.
Setting zfs_arc_lotsfree_percent=0 will have the same effect as
zfs_arc_memory_throttle_disable and it was therefore redundant.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3637
While Linux doesn't provide detailed information about the state of
the VM it does provide us total free pages. This information should
be incorporated in to the arc_available_memory() calculation rather
than solely relying on a signal from direct reclaim. Conceptually
this brings arc_available_memory() back in sync with illumos.
It is also desirable that the target amount of free memory be tunable
on a system. While the default values are expected to work well
for most workloads there may be cases where custom values are needed.
The zfs_arc_sys_free module option was added for this purpose.
zfs_arc_sys_free - The target number of bytes the ARC should leave
as free memory on the system. This value can
checked in /proc/spl/kstat/zfs/arcstats and
setting this module option will override the
default value.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3637
The zvol_threads module option should be bounded to a reasonable
range. The taskq must have at least 1 thread and shouldn't have
more than 1,024 at most. The default value of 32 is a reasonable
default.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3614
Commit d958324 fixed the deadlock between page lock and range lock by
unlocking the page lock before acquiring the range lock. However,
this created a new issue #3075.
The problem is that if we can't set the write back bit before releasing
the page lock. Then other processes will be unaware that the page is
under active write back. They may therefore truncate the page,
invalidate the page, or not honor the sync semantics.
To workaround this problem we re-dirty the page before dropping the
page lock. While this doesn't prevent the page from being truncated
it does ensure it won't be invalidated. Then the range lock and the
page lock are reacquired in the correct deadlock-free order.
Once both locks are safely held the page state can be rechecked. If
all is well and the page is in the expect state the dirty bit can be
removed, the write back bit set, and the page removed from the skip
count. If not the page will be handled as appropriate.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3075
Brian Behlendorf
Andrey Vesnovaty
Richard Yao
Tim Chase
James Lee
tuxoko
loli10K
Andreas Buschmann
Richard Yao
Chris Dunlop
Chris Dunlap