Commit Graph

354 Commits

Author SHA1 Message Date
Richard Yao
44f21da41c Revert Disable direct reclaim for z_wr_* threads
This commit used PF_MEMALLOC to prevent a memory reclaim deadlock.
However, commit 49be0ccf1f eliminated
the invocation of __cv_init(), which was the cause of the deadlock.
PF_MEMALLOC has the side effect of permitting pages from ZONE_DMA
to be allocated.  The use of PF_MEMALLOC was found to cause stability
problems when doing swap on zvols. Since this technique is known to
cause problems and no longer fixes anything, we revert it.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #726
2012-08-27 12:01:37 -07:00
Richard Yao
62c4165a1b Revert Fix zpl_writepage() deadlock
The commit, cfc9a5c88f, to fix deadlocks
in zpl_writepage() relied on PF_MEMALLOC.   That had the effect of
disabling the direct reclaim path on all allocations originating from
calls to this function, but it failed to address the actual cause of
those deadlocks.  This led to the same deadlocks being observed with
swap on zvols, but not with swap on the loop device, which exercises
this code.

The use of PF_MEMALLOC also had the side effect of permitting
allocations to be made from ZONE_DMA in instances that did not require
it.  This contributes to the possibility of panics caused by depletion
of pages from ZONE_DMA.

As such, we revert this patch in favor of a proper fix for both issues.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #726
2012-08-27 12:01:37 -07:00
Richard Yao
b876dac776 Revert Fix ASSERTION(!dsl_pool_sync_context(tx->tx_pool))
Commit eec8164771 worked around an issue
involving direct reclaim through the use of PF_MEMALLOC.   Since we
are reworking thing to use KM_PUSHPAGE so that swap works, we revert
this patch in favor of the use of KM_PUSHPAGE in the affected areas.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #726
2012-08-27 12:01:37 -07:00
Brian Behlendorf
cd38ac58a3 rmdir(2) should return ENOTEMPTY
Under Solaris the behavior for rmdir(2) is to return EEXIST when
a directory still contains entries.  However, on Linux ENOTEMPTY
is the expected return value with EEXIST being technically allowed.
According to rmdir(2):

ENOTEMPTY
   pathname contains entries other than . and .. ; or, pathname has
   ..  as its final component.  POSIX.1-2001 also allows EEXIST for
   this condition.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #895
2012-08-26 13:55:45 -07:00
Christopher Siden
9e11c7eee2 Illumos #3085: zfs diff panics, then panics in a loop on booting
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/3085

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-25 12:32:25 -07:00
Simon Klinkert
c578f007ff Illumos #2901: zfs receive fails for exabyte sparse files
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/2901

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-25 12:28:29 -07:00
Javen Wu
a47587389e Drop spill buffer reference
When calling sa_update() and friends it is possible that a spill
buffer will be needed to accomidate the update.  When this happens
a hold is taken on the new dbuf and that hold must be released
before calling dmu_tx_commit().  Failing to release the hold will
cause a copy of the dbuf to be made in dbuf_sync_leaf().  This is
done to ensure further updates to the dbuf never sneak in to the
syncing txg.

This could be left to the sa_update() caller.  But then the caller
would need to be aware of this internal SA implementation detail.
It is therefore preferable to handle this all internally in the
SA implementation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #503
Closes #513
2012-08-25 09:26:10 -07:00
Brian Behlendorf
f828e63a0d Revert "Use SA_HDL_PRIVATE for SA xattrs"
This reverts commit ec2626ad3f which
caused consistency problems between the shared and private handles.
Reverting this change should resolve issues #709 and #727.  It
will also reintroduce an arc_anon memory leak which is addressed
by the next commit.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #709
Closes #727
2012-08-25 09:25:56 -07:00
Prakash Surya
15a9e03368 Wrap smp_processor_id in kpreempt_[dis|en]able
After surveying the code, the few places where smp_processor_id is used
were deemed to be safe to use with a preempt enabled kernel. As such, no
core logic had to be changed. These smp_processor_id call sites are simply
are wrapped in kpreempt_disable and kpreempt_enabled to prevent the
Linux kernel from emitting scary warnings.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Issue #83
2012-08-24 13:19:06 -07:00
Brian Behlendorf
4047414a6a Export dmu_buf_rele() symbol
While I'd like to remove the various pragmas in module/zfs/dbuf.c.
There are consumers such as Lustre which still depend on dmu_buf_*
versions of the symbols.  Until all consumers can be converted to
use only the dbuf_* names leave this symbol exported.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-14 08:38:19 -07:00
Brian Behlendorf
bafc4e9e2a Suppress 'zfs_sb_create' memory warning
When mutex debugging is enabled in your kernel the increased
size of the mutex structures can push the zfs_sb_t type beyond
the 8k warning threshold.  This isn't harmful so we suppress
the warning for this case.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #628
2012-08-10 16:43:32 -07:00
Brian Behlendorf
8f576c2321 Export dbuf_* symbols
Export these symbols so they may be used by other ZFS consumers
besides the ZPL.

Remove three stale prototype definites from dbuf.h.  The actual
implementations of these functions were removed/renamed long ago.

It would be good in the long term to remove the existing pragmas
we inherited from Solaris and simply use the dbuf_* names.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-10 16:45:13 -07:00
Dan McDonald
d96eb2b153 Illumos #1693: persistent 'comment' field for a zpool
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/1693

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #678
2012-08-08 11:49:37 -07:00
Etienne Dechamps
ee5fd0bb80 Set zvol discard_granularity to the volblocksize.
Currently, zvols have a discard granularity set to 0, which suggests to
the upper layer that discard requests of arbirarily small size and
alignment can be made efficiently.

In practice however, ZFS does not handle unaligned discard requests
efficiently: indeed, it is unable to free a part of a block. It will
write zeros to the specified range instead, which is both useless and
inefficient (see dnode_free_range).

With this patch, zvol block devices expose volblocksize as their discard
granularity, so the upper layer is aware that it's not supposed to send
discard requests smaller than volblocksize.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #862
2012-08-07 14:55:31 -07:00
Etienne Dechamps
7c0e570888 Limit the number of blocks to discard at once.
The number of blocks that can be discarded in one BLKDISCARD ioctl on a
zvol is currently unlimited. Some applications, such as mkfs, discard
the whole volume at once and they use the maximum possible discard size
to do that. As a result, several gigabytes discard requests are not
uncommon.

Unfortunately, if a large amount of data is allocated in the zvol, ZFS
can be quite slow to process discard requests. This is especially true
if the volblocksize is low (e.g. the 8K default). As a result, very
large discard requests can take a very long time (seconds to minutes
under heavy load) to complete. This can cause a number of problems, most
notably if the zvol is accessed remotely (e.g. via iSCSI), in which case
the client has a high probability of timing out on the request.

This patch solves the issue by adding a new tunable module parameter:
zvol_max_discard_blocks. This indicates the maximum possible range, in
zvol blocks, of one discard operation. It is set by default to 16384
blocks, which appears to be a good tradeoff. Using the default
volblocksize of 8K this is equivalent to 128 MB. When using the maximum
volblocksize of 128K this is equivalent to 2 GB.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #858
2012-07-31 09:46:09 -07:00
Matthew Ahrens
330d06f90d Illumos #1644, #1645, #1646, #1647, #1708
1644 add ZFS "clones" property
1645 add ZFS "written" and "written@..." properties
1646 "zfs send" should estimate size of stream
1647 "zfs destroy" should determine space reclaimed by
     destroying multiple snapshots
1708 adjust size of zpool history data

References:
  https://www.illumos.org/issues/1644
  https://www.illumos.org/issues/1645
  https://www.illumos.org/issues/1646
  https://www.illumos.org/issues/1647
  https://www.illumos.org/issues/1708

This commit modifies the user to kernel space ioctl ABI.  Extra
care should be taken when updating to ensure both the kernel
modules and utilities are updated.  This change has reordered
all of the new ioctl()s to the end of the list.  This should
help minimize this issue in the future.

Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Albert Lee <trisk@opensolaris.org>
Approved by: Garrett D'Amore <garret@nexenta.com>

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #826
Closes #664
2012-07-31 09:25:30 -07:00
Etienne Dechamps
2ee4a18b2a Add script for builtin module building.
This commit introduces a "copy-builtin" script designed to prepare a
kernel source tree for building ZFS as a builtin module. The script
makes a full copy of all needed files, thus making the kernel source
tree fully independent of the zfs source package.

To achieve that, some compilation flags (-include, -I) have been moved
to module/Makefile. This Makefile is only used when compiling external
modules; when compiling builtin modules, a Kbuild file generated by the
configure-builtin script is used instead. This makes sure Makefiles
inside the kernel source tree does not contain references to the zfs
source package.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #851
2012-07-26 13:45:09 -07:00
Richard Yao
739a1a82e0 Linux 3.5 compat, end_writeback() changed to clear_inode()
The end_writeback() function was changed by moving the call to
inode_sync_wait() earlier in to evict().   This effecitvely changes
the ordering of the sync but it does not impact the details of
the zfs implementation.

However, as part of this change end_writeback() was renamed to
clear_inode() to reflect the new semantics.  This change does
impact us and clear_inode() now maps to end_writeback() for
kernels prior to 3.5.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #784
2012-07-23 12:29:36 -07:00
Richard Yao
ea1fdf46e2 Linux 3.5 compat, iops->truncate_range() removed
The vmtruncate_range() support has been removed from the kernel in
favor of using the fallocate method in the file_operations table.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #784
2012-07-23 12:29:32 -07:00
Richard Yao
756c3e5a9c Linux 3.5 compat, eops->encode_fh() takes inodes
The export_operations member ->encode_fh() has been updated to
take both the child and parent inodes.  This interface used to
take the child dentry and a bool describing if the parent is needed.

NOTE: While updating this code I noticed that we do not currently
cleanly handle the case where we're passed a connectable parent.
This code should be audited to make sure we're doing the right thing.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #784
2012-07-23 12:29:23 -07:00
Brian Behlendorf
fc173c8589 Disable .zfs directory on 32-bit systems
The .zfs control directory implementation currently relies on
the fact that there is a direct 1:1 mapping from an object id
to its inode number.  This works well as long as the system
uses a 64-bit value to store the inode number.

Unfortunately, the Linux kernel defines the inode number as
an 'unsigned long' type.  This means that for 32-bit systems
will only have 32-bit inode numbers but we still have 64-bit
object ids.

This problem is particularly acute for the .zfs directories
which leverage those upper 32-bits.  This is done to avoid
conflicting with object ids which are allocated monotonically
starting from 0.  This is likely to also be a problem for
datasets on 32-bit systems with more than ~2 billion files.

The right long term fix must remove the simple 1:1 mapping.
Until that's done the only safe thing to do is to disable the
.zfs directory on 32-bit systems.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-07-20 12:20:57 -07:00
Brian Behlendorf
2a4a9dc2f0 Add ddt_object_load() error handling
Add the missing error handling to ddt_object_load().  There's no
good reason this needs to be fatal.  It is preferable that an
error be returned.  This will allow 'zpool import -FX' to safely
attempt to rollback through previous txgs looking for a good one.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-07-20 10:36:21 -07:00
Brian Behlendorf
10be533e33 Add 'inline' keyword
The '__attribute__((always_inline))' does not strictly imply
'inline'.  Newer versions of gcc detect this misuse and issue
the following warning.  Including the missing 'inline' resolves
the build warning.

    ./module/zfs/dsl_scan.c:758:1:error: always_inline function
    might not be inlinable [-Werror=attributes]

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-07-19 13:41:00 -07:00
Richard Yao
0a6b03d3b8 Fix build failures on PaX/GRSecurity patched kernels
Gentoo Hardened kernels include the PaX/GRSecurity patches. They use a
dialect of C that relies on a GCC plugin. In particular, struct
file_operations has been marked do_const in the PaX/GRSecurity dialect,
which causes GCC to consider all instances of it as const. This caused
failures in the autotools checks and the ZFS source code.

To address this, we modify the autotools checks to take into account
differences between the PaX C dialect and the regular C dialect. We also
modify struct zfs_acl's z_ops member to be a pointer to a function
pointer table. Lastly, we modify zpl_put_link() to address a PaX change
to the function prototype of nd_get_link().  This avoids compiler errors
in the PaX/GRSecurity dialect.

Note that the change in zpl_put_link() causes a warning that becomes a
build failure when debugging is enabled. Fixing that warning requires
ryao/spl@5ca50ef459.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #484
2012-07-17 09:22:43 -07:00
Etienne Dechamps
b5a28807cd Move partition scanning from userspace to module.
Currently, zpool online -e (dynamic vdev expansion) doesn't work on
whole disks because we're invoking ioctl(BLKRRPART) from userspace
while ZFS still has a partition open on the disk, which results in
EBUSY.

This patch moves the BLKRRPART invocation from the zpool utility to the
module. Specifically, this is done just before opening the device in
vdev_disk_open() which is called inside vdev_reopen(). This requires
jumping through some hoops to get to the disk device from the partition
device, and to make sure we can still open the partition after the
BLKRRPART call.

Note that this new code path is triggered on dynamic vdev expansion
only; other actions, like creating a new pool, are unchanged and still
call BLKRRPART from userspace.

This change also depends on API changes which are available in 2.6.37
and latter kernels.  The build system has been updated to detect this,
but there is no compatibility mode for older kernels.  This means that
online expansion will NOT be available in older kernels.  However, it
will still be possible to expand the vdev offline.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #808
2012-07-17 09:17:31 -07:00
George Wilson
c7f2d69de3 Illumos #1949, #1953
1949 crash during reguid causes stale config
1953 allow and unallow missing from zpool history since removal of pyzfs

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Garrett D'Amore <garrett.damore@gmail.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Steve Gonczi <gonczi@comcast.net>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References:
  https://www.illumos.org/issues/1949
  https://www.illumos.org/issues/1953

Ported by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #665
2012-07-11 13:33:31 -07:00
Garrett D'Amore
3541dc6d02 Illumos #1748: desire support for reguid in zfs
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: Alexander Eremin <alexander.eremin@nexenta.com>
Reviewed by: Alexander Stetsenko <ams@nexenta.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/1748

This commit modifies the user to kernel space ioctl ABI.  Extra
care should be taken when updating to ensure both the kernel
modules and utilities are updated.  If only the user space
component is updated both the 'zpool events' command and the
'zpool reguid' command will not work until the kernel modules
are updated.

Ported by:     Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #665
2012-07-11 13:08:56 -07:00
Brian Behlendorf
42d3b990cf Update incorrect ddt_zap_lookup() assertion
When the ddt_zap_lookup() function was updated to dynamically
allocate memory for the cbuf variable, to save stack space, the
'csize <= sizeof (cbuf)' assertion was not updated.  The result
of this was that the size of the pointer was being used in the
comparison rather than the buffer size.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
2012-07-03 15:14:34 -07:00
Etienne Dechamps
b6ad9671ac Add ZIL statistics.
The performance of the ZIL is usually the main bottleneck when dealing with
synchronous, write-heavy workloads (e.g. databases). Understanding the
behavior of the ZIL is required to diagnose performance issues for these
workloads, and to tune ZIL parameters (like zil_slog_limit) accordingly.

This commit adds a new kstat page dedicated to the ZIL with some counters
which, hopefully, scheds some light into what the ZIL is doing, and how it is
doing it.

Currently, these statistics are available in /proc/spl/kstat/zfs/zil.
A description of the fields can be found in zil.h.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #786
2012-06-29 09:56:51 -07:00
Pawel Jakub Dawidek
0cee24064a Speed up 'zfs list -t snapshot -o name -s name'
FreeBSD #xxx:  Dramatically optimize listing snapshots when user
requests only snapshot names and wants to sort them by name, ie.
when executes:

  # zfs list -t snapshot -o name -s name

Because only name is needed we don't have to read all snapshot
properties.

Below you can find how long does it take to list 34509 snapshots
from a single disk pool before and after this change with cold and
warm cache:

    before:

        # time zfs list -t snapshot -o name -s name > /dev/null
        cold cache: 525s
        warm cache: 218s

    after:

        # time zfs list -t snapshot -o name -s name > /dev/null
        cold cache: 1.7s
        warm cache: 1.1s

NOTE: This patch only appears in FreeBSD.  If/when Illumos picks up
the change we may want to drop this patch and adopt their version.
However, for now this addresses a real issue.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #450
2012-06-14 09:49:04 -07:00
Darik Horn
74497b7ab6 Add zvol_inhibit_dev module option.
ZoL can create more zvols at runtime than can be configured during
system start, which hangs the init stack at reboot.

When a slow system has more than a few hundred zvols, udev will
fork bomb during system start and spend too much time in device
detection routines, so upstart kills it.

The zfs_inhibit_dev option allows an affected system to be rescued
by skipping /dev/zd* creation and thereby avoiding the udev
overload. All zvols are made inaccessible if this option is set, but
the `zfs destroy` and `zfs send` commands still work, and ZFS
filesystems can be mounted.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-06-13 17:05:16 -07:00
Etienne Dechamps
ee191e802c Make zil_slog_limit a tunable module parameter.
zil_slog_limit specifies the maximum commit size to be written to the separate
log device. Larger commits bypass the separate log device and go directly to
the data devices.

The optimal value for zil_slog_limit directly depends on the latency and
throughput characteristics of both the separate log device and the data disks.
Small synchronous writes are faster on low-latency separate log devices (e.g.
SSDs) whereas large synchronous writes are faster on high-latency data disks
(e.g. spindles) because of higher throughput, especially with a large array.
The point is, the line between "small" and "large" synchronous writes in this
scenario is heavily dependent on the hardware used. That's why it should be
made configurable.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #783
2012-06-12 08:45:53 -07:00
Richard Yao
6a0936babc Linux 3.4 compat, d_make_root() replaces d_alloc_root()
torvalds/linux@adc0e91ab1 introduced
introduced d_make_root() as a replacement for d_alloc_root(). Further
commits appear to have removed d_alloc_root() from the Linux source
tree. This causes the following failure:

  error: implicit declaration of function 'd_alloc_root'
  [-Werror=implicit-function-declaration]

To correct this we update the code to use the current d_make_root()
interface for readability.  Then we introduce an autotools check
to determine if d_make_root() is available.  If it isn't then we
define some compatibility logic which used the older d_alloc_root()
interface.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #776
2012-06-11 10:04:49 -07:00
Etienne Dechamps
ab85f8455b Honor logbias when writing to ZVOLs.
The logbias option is not taken into account when writing to ZVOLs. We fix
that by using the same logic as in the zfs filesystem write code
(see zfs_log.c).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #774
2012-06-11 09:43:48 -07:00
Brian Behlendorf
710114089f Revert "Disable direct reclaim on zvols"
This reverts commit ce90208cf9.  This
change was observed to cause problems when using a zvol to back a VM
under 2.6.32.59 kernels.  This issue was filed as #710.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #342
Issue #710
2012-04-30 14:26:49 -07:00
Brian Behlendorf
b39d3b9f7b Linux 3.3 compat, iops->create()/mkdir()/mknod()
The mode argument of iops->create()/mkdir()/mknod() was changed from
an 'int' to a 'umode_t'.  To prevent a compiler warning an autoconf
check was added to detect the API change and then correctly set a
zpl_umode_t typedef.  There is no functional change.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #701
2012-04-30 12:52:38 -07:00
Richard Yao
ce90208cf9 Disable direct reclaim on zvols
Previously, it was possible for the direct reclaim path to be invoked
when a write to a zvol was made. When a zvol is used as a swap device,
this often causes swap requests to depend on additional swap requests,
which deadlocks. We address this by disabling the direct reclaim path
on zvols.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #342
2012-04-30 11:25:36 -07:00
Richard Yao
518b487602 Update ARC memory limits to account for SLUB internal fragmentation
23bdb07d4e updated the ARC memory limits
to be 1/2 of memory or all but 4GB. Unfortunately, these values assume
zero internal fragmentation in the SLUB allocator, when in reality, the
internal fragmentation could be as high as 50%, effectively doubling
memory usage. This poses clear safety issues, because it permits the
size of ARC to exceed system memory.

This patch changes this so that the default value of arc_c_max is always
1/2 of system memory. This effectively limits the ARC to the memory that
the system has physically installed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #660
2012-04-30 10:04:34 -07:00
Brian Behlendorf
302f753f16 Integrate ARC more tightly with Linux
Under Solaris the ARC was designed to stay one step ahead of the
VM subsystem.  It would attempt to recognize low memory situtions
before they occured and evict data from the cache.  It would also
make assessments about if there was enough free memory to perform
a specific operation.

This was all possible because Solaris exposes a fairly decent
view of the memory state of the system to other kernel threads.
Linux on the other hand does not make this information easily
available.  To avoid extensive modifications to the ARC the SPL
attempts to provide these same interfaces.  While this works it
is not ideal and problems can arise when the ARC and Linux have
different ideas about when your out of memory.  This has manifested
itself in the past as a spinning arc_reclaim_thread.

This patch abandons the emulated Solaris interfaces in favor of
the prefered Linux interface.  That means moving the bulk of the
memory reclaim logic out of the arc_reclaim_thread and in to the
evict driven shrinker callback.  The Linux VM will call this
function when it needs memory.  The ARC is then responsible for
attempting to free the requested amount of memory if possible.

Several interfaces have been modified to accomidate this approach,
however the basic user space implementation remains the same.
The following changes almost exclusively just apply to the kernel
implementation.

* Removed the hdr_recl() reclaim callback which is redundant
  with the broader arc_shrinker_func().

* Reduced arc_grow_retry to 5 seconds from 60.  This is now used
  internally in the ARC with arc_no_grow to indicate that direct
  reclaim was recently performed.  This typically indicates a
  rapid change in memory demands which the kswapd threads were
  unable to keep ahead of.  As long as direct reclaim is happening
  once every 5 seconds arc growth will be paused to avoid further
  contributing to the existing memory pressure.  The more common
  indirect reclaim paths will not set arc_no_grow.

* arc_shrink() has been extended to take the number of bytes by
  which arc_c should be reduced.  This allows for a more granual
  reduction of the arc target.  Since the kernel provides a
  reclaim value to the arc_shrinker_func() this value is used
  instead of 1<<arc_shrink_shift.

* arc_reclaim_needed() has been removed.  It was used to determine
  if the system was under memory pressure and relied extensively
  on Solaris specific VM interfaces.  In most case the new code
  just checks arc_no_grow which indicates that within the last
  arc_grow_retry seconds direct memory reclaim occurred.

* arc_memory_throttle() has been updated to always include the
  amount of evictable memory (arc and page cache) in its free
  space calculations.  This space is largely available in most
  call paths due to direct memory reclaim.

* The Solaris pageout code was also removed to avoid confusion.
  It has always been disabled due to proc_pageout being defined
  as NULL in the Linux port.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-30 10:03:05 -07:00
Brian Behlendorf
afec56b43f Add zfs_mdcomp_disable module option
Expose the zfs_mdcomp_disable variable as a module option.  This
can be used to disable compression of zfs meta data which is
enabled by default.  This shouldn't need to be tuned but for
most workloads, however there may be very specific instances
where it makes sense to trade disk capacity for extra cpu cycles.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-27 16:28:02 -07:00
Brian Behlendorf
ebf8e3a237 Illumos #1909: disk sync write perf regression when slog is used post oi_148
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Steve Gonczi <gonczi@comcast.net>
Reviewed by: Garrett D'Amore <garrett.damore@gmail.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Albert Lee <trisk@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>

Refererces to Illumos issue:
  https://www.illumos.org/issues/1909

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #680
2012-04-19 16:26:29 -07:00
Prakash Surya
409dc1a570 Use KM_PUSHPAGE in l2arc_write_buffers
There is potential for deadlock in the l2arc_feed thread if KM_PUSHPAGE
is not used for the allocations made in l2arc_write_buffers.
Specifically, if KM_PUSHPAGE is not used for these allocations, it is
possible for reclaim to be triggered which can cause the l2arc_feed
thread to deadlock itself on the ARC_mru mutex. An example of this is
demonstrated in the following backtrace of the l2arc_feed thread:

    crash> bt 4123
    PID: 4123   TASK: ffff88062f8c1500  CPU: 6   COMMAND: "l2arc_feed"
      0 [ffff88062511d610] schedule at ffffffff814eeee0
      1 [ffff88062511d6d8] __mutex_lock_slowpath at ffffffff814f057e
      2 [ffff88062511d748] mutex_lock at ffffffff814f041b
      3 [ffff88062511d768] arc_evict at ffffffffa05130ca [zfs]
      4 [ffff88062511d858] arc_adjust at ffffffffa05139a9 [zfs]
      5 [ffff88062511d878] arc_shrink at ffffffffa0513a95 [zfs]
      6 [ffff88062511d898] arc_kmem_reap_now at ffffffffa0513be8 [zfs]
      7 [ffff88062511d8c8] arc_shrinker_func at ffffffffa0513ccc [zfs]
      8 [ffff88062511d8f8] shrink_slab at ffffffff8112a17a
      9 [ffff88062511d958] do_try_to_free_pages at ffffffff8112bfdf
     10 [ffff88062511d9e8] try_to_free_pages at ffffffff8112c3ed
     11 [ffff88062511da98] __alloc_pages_nodemask at ffffffff8112431d
     12 [ffff88062511dbb8] kmem_getpages at ffffffff8115e632
     13 [ffff88062511dbe8] fallback_alloc at ffffffff8115f24a
     14 [ffff88062511dc68] ____cache_alloc_node at ffffffff8115efc9
     15 [ffff88062511dcc8] __kmalloc at ffffffff8115fbf9
     16 [ffff88062511dd18] kmem_alloc_debug at ffffffffa047b8cb [spl]
     17 [ffff88062511dda8] l2arc_feed_thread at ffffffffa0511e71 [zfs]
     18 [ffff88062511dea8] thread_generic_wrapper at ffffffffa047d1a1 [spl]
     19 [ffff88062511dee8] kthread at ffffffff81090a86
     20 [ffff88062511df48] kernel_thread at ffffffff8100c14a

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-17 11:56:21 -07:00
Martin Matuska
7d5cd71da6 Illumos #1346: zfs incremental receive may leave behind temporary clones
1356 zfs dataset prefetch code not working
Reviewed by: Matthew Ahrens <matt@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References to Illumos issue:
  https://www.illumos.org/issues/1346
  https://www.illumos.org/issues/1356

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #647
2012-04-11 12:02:27 -07:00
Albert Lee
22cd4a4653 Illumos #1475: zfs spill block hold can access invalid spill blkptr
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Approved by: Garrett D'Amore <garrett@nexenta.com>

References to Illumos issue:
  https://www.illumos.org/issues/1475

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #648
2012-04-11 11:46:30 -07:00
George Wilson
5ffb9d1d05 Illumos #1951: leaking a vdev when removing an l2cache device
1952 memory leak when adding a file-based l2arc device
1954 leak in ZFS from metaslab_group_create and zfs_ereport_checksum

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References to Illumos issues:
  https://www.illumos.org/issues/1951
  https://www.illumos.org/issues/1952
  https://www.illumos.org/issues/1954

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #650
2012-04-11 11:32:06 -07:00
Martin Matuska
b129c6590e OS-926: zfs panic in zfs_fill_zplprops_impl()
This change appears to be exclusive to SmartOS. It is not present in
illumos-gate but it just adds some needed error handling.  This is
clearly preferable to simply ASSERTING which is what would occur
prior to the patch.

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #652
2012-04-11 11:29:19 -07:00
Andriy Gapon
3adfc400f5 Illumos #1680: zfs vdev_file_io_start: validate vdev before using vdev_tsd
vdev_tsd can be NULL for certain vdev states.
At least in userland testing with ztest.

References to Illumos issue:
  https://www.illumos.org/issues/1680

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #655
2012-04-11 11:23:18 -07:00
Brian Behlendorf
f0fd83be65 Export additional dsl symbols
Principly these symbols were exported to get access to the
dsl_prop_register/dsl_prop_unregister functions.  They allow
us to cleanly register a callback which is called when a
dataset property is modified.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-11 09:26:55 -07:00
Gunnar Beutner
1f0d8a566f Fixed a NULL pointer dereference bug in zfs_preumount
When zpl_fill_super -> zfs_domount fails (e.g. because the dataset
was destroyed before it could be successfully mounted) the subsequent
call to zpl_kill_sb -> zfs_preumount would derefence a NULL pointer.

This bug can be reproduced using this shell script:

 #!/bin/sh
 (
 while true; do
 	zfs create -o mountpoint=legacz tank/bar
 	zfs destroy tank/bar
 done
 ) &

 (
 while true; do
 	mount -t zfs tank/bar /mnt
 	umount /mnt
 done
 ) &

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #639
2012-04-05 11:29:42 -07:00
Brian Behlendorf
fc41c6402b Properly expose the mfu ghost list kstats
Due to a typo the mru ghost lists stats were accidentally being
exposed as the mfu ghost list stats.  This was harmless but
confusing since memory usage could be over reported.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-03-27 15:08:22 -07:00