New SSDs are now available which use an internal 8k block size.
To make sure ZFS can get the maximum performance out of these
devices we're increasing the maximum ashift to 13 (8KB).
This value is still small enough that we can fit 16 uberblocks
in the vdev ring label. However, I don't want to increase this
any futher or it will limit the ability the safely roll back a
pool to recover it.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#565
Resolves nfs-utils-1.0.x compatibility issue which requires
that the fsid be set in the export options.
exportfs: Warning: /tank/dir requires fsid= for NFS export
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#570
Exported the required symbols to make use of the DMU's zero-copy
API. This allows external modules to move data in to and out of
the ARC without incurring the cost of a memory copy.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When building the spl with --disable-debug-log the __SDEBUG()
macro and spl_debug_* helper functions were undefined. This
change adds the missing functions so the upper layers compiling
against the spl don't need to be aware of how the spl was built.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When configuring the spl debug log support use the provided wrapper
functions. This ensures that if --disable-debug-log was used when
buiding the spl the functions will have no effect.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
DISCARD (REQ_DISCARD, BLKDISCARD) is useful for thin provisioning.
It allows ZVOL clients to discard (unmap, trim) block ranges from
a ZVOL, thus optimizing disk space usage by allowing a ZVOL to
shrink instead of just grow.
We can't use zfs_space() or zfs_freesp() here, since these functions
only work on regular files, not volumes. Fortunately we can use the
low-level function dmu_free_long_range() which does exactly what we
want.
Currently the discard operation is not added to the log. That's not
a big deal since losing discard requests cannot result in data
corruption. It would however result in disk space usage higher than
it should be. Thus adding log support to zvol_discard() is probably
a good idea for a future improvement.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is
supported, since it's the only one that matches the behavior of
zfs_space(). This makes it pretty much useless in its current
form, but it's a start.
To support other flag combinations we would need to modify
zfs_space() to make it more flexible, or emulate the desired
functionality in zpl_fallocate().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
This isn't done on Solaris because on this OS zfs_space() can
only be called with an opened file handle. Since the addition of
zpl_truncate_range() this isn't the case anymore, so we need to
enforce access rights.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
This operation allows "hole punching" in ZFS files. On Solaris this
is done via the vop_space() system call, which maps to the zfs_space()
function. So we just need to write zpl_truncate_range() as a wrapper
around zfs_space().
Note that this only works for regular files, not ZVOLs.
This is currently an insecure implementation without permission
checking, although this isn't that big of a deal since truncate_range()
isn't even callable from userspace.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
The recent zvol improvements have changed default suggested alignment
for zvols from 512b (default) to 8k (zvol blocksize). Because of this
the zconfig.sh tests which create paritions are now generating a
warning about non-optimal alignments.
This change updates the need zconfig.sh tests such that a partition
will be properly aligned. In the process, it shifts from using the
sfdisk utility to the parted utility to create partitions. It also
moves the creation of labels, partitions, and filesystems in to
generic functions in common.sh.in.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Currently, the `zvol_threads` variable, which controls the number of worker
threads which process items from the ZVOL queues, is set to the number of
available CPUs.
This choice seems to be based on the assumption that ZVOL threads are
CPU-bound. This is not necessarily true, especially for synchronous writes.
Consider the situation described in the comments for `zil_commit()`, which is
called inside `zvol_write()` for synchronous writes:
> itxs are committed in batches. In a heavily stressed zil there will be a
> commit writer thread who is writing out a bunch of itxs to the log for a
> set of committing threads (cthreads) in the same batch as the writer.
> Those cthreads are all waiting on the same cv for that batch.
>
> There will also be a different and growing batch of threads that are
> waiting to commit (qthreads). When the committing batch completes a
> transition occurs such that the cthreads exit and the qthreads become
> cthreads. One of the new cthreads becomes he writer thread for the batch.
> Any new threads arriving become new qthreads.
We can easily deduce that, in the case of ZVOLs, there can be a maximum of
`zvol_threads` cthreads and qthreads. The default value for `zvol_threads` is
typically between 1 and 8, which is way too low in this case. This means
there will be a lot of small commits to the ZIL, which is very inefficient
compared to a few big commits, especially since we have to wait for the data
to be on stable storage. Increasing the number of threads will increase the
amount of data waiting to be commited and thus the size of the individual
commits.
On my system, in the context of VM disk image storage (lots of small
synchronous writes), increasing `zvol_threads` from 8 to 32 results in a 50%
increase in sequential synchronous write performance.
We should choose a more sensible default for `zvol_threads`. Unfortunately
the optimal value is difficult to determine automatically, since it depends
on the synchronous write latency of the underlying storage devices. In any
case, a hardcoded value of 32 would probably be better than the current
situation. Having a lot of ZVOL threads doesn't seem to have any real
downside anyway.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fixes#392
The Linux block device queue subsystem exposes a number of configurable
settings described in Linux block/blk-settings.c. The defaults for these
settings are tuned for hard drives, and are not optimized for ZVOLs. Proper
configuration of these options would allow upper layers (I/O scheduler) to
take better decisions about write merging and ordering.
Detailed rationale:
- max_hw_sectors is set to unlimited (UINT_MAX). zvol_write() is able to
handle writes of any size, so there's no reason to impose a limit. Let the
upper layer decide.
- max_segments and max_segment_size are set to unlimited. zvol_write() will
copy the requests' contents into a dbuf anyway, so the number and size of
the segments are irrelevant. Let the upper layer decide.
- physical_block_size and io_opt are set to the ZVOL's block size. This
has the potential to somewhat alleviate issue #361 for ZVOLs, by warning
the upper layers that writes smaller than the volume's block size will be
slow.
- The NONROT flag is set to indicate this isn't a rotational device.
Although the backing zpool might be composed of rotational devices, the
resulting ZVOL often doesn't exhibit the same behavior due to the COW
mechanisms used by ZFS. Setting this flag will prevent upper layers from
making useless decisions (such as reordering writes) based on incorrect
assumptions about the behavior of the ZVOL.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
zvol_write() assumes that the write request must be written to stable storage
if rq_is_sync() is true. Unfortunately, this assumption is incorrect. Indeed,
"sync" does *not* mean what we think it means in the context of the Linux
block layer. This is well explained in linux/fs.h:
WRITE: A normal async write. Device will be plugged.
WRITE_SYNC: Synchronous write. Identical to WRITE, but passes down
the hint that someone will be waiting on this IO
shortly.
WRITE_FLUSH: Like WRITE_SYNC but with preceding cache flush.
WRITE_FUA: Like WRITE_SYNC but data is guaranteed to be on
non-volatile media on completion.
In other words, SYNC does not *mean* that the write must be on stable storage
on completion. It just means that someone is waiting on us to complete the
write request. Thus triggering a ZIL commit for each SYNC write request on a
ZVOL is unnecessary and harmful for performance. To make matters worse, ZVOL
users have no way to express that they actually want data to be written to
stable storage, which means the ZIL is broken for ZVOLs.
The request for stable storage is expressed by the FUA flag, so we must
commit the ZIL after the write if the FUA flag is set. In addition, we must
commit the ZIL before the write if the FLUSH flag is set.
Also, we must inform the block layer that we actually support FLUSH and FUA.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Currently the "sync=always" property works for regular ZFS datasets, but not
for ZVOLs. This patch remedies that.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fixes#374.
Autoconf will fail to detect the ZoL libnvpair on systems that do not
implicitly link library runtime dependencies, which is anything that
has the GCC 4.5 DCO update.
Build libuutil before libnvpair, and put it on the the LDADD line of
the libnvpair automake template.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #560
The second argument of sops->show_options() was changed from a
'struct vfsmount *' to a 'struct dentry *'. Add an autoconf check
to detect the API change and then conditionally define the expected
interface. In either case we are only interested in the zfs_sb_t.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#549
Add the bare minimum functionality to support dynamic kstats. A
complete kstat implementation should be done as part of issue #84.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #84
Until now the notion of an internal debug logging infrastructure
was conflated with enabling ASSERT()s. This patch clarifies things
by cleanly breaking the two subsystem apart. The result of this
is the following behavior.
--enable-debug - Enable/disable code wrapped in ASSERT()s.
--disable-debug ASSERT()s are used to check invariants and
are never required for correct operation.
They are disabled by default because they
may impact performance.
--enable-debug-log - Enable/disable the debug log infrastructure.
--disable-debug-log This infrastructure allows the spl code and
its consumer to log messages to an in-kernel
log. The granularity of the logging can be
controlled by a debug mask. By default the
mask disables most debug messages resulting
in a negligible performance impact. Because
of this the debug log is enabled by default.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Historically the internal zfs debug infrastructure has been
scattered throughout the code. Since we expect to start making
more use of this code this patch performs some cleanup.
* Consolidate the zfs debug infrastructure in the zfs_debug.[ch]
files. This includes moving the zfs_flags and zfs_recover
variables, plus moving the zfs_panic_recover() function.
* Remove the existing unused functionality in zfs_debug.c and
replace it with code which correctly utilized the spl logging
infrastructure.
* Remove the __dprintf() function from zfs_ioctl.c. This is
dead code, the dprintf() functionality in the kernel relies
on the spl log support.
* Remove dprintf() from hdr_recl(). This wasn't particularly
useful and was missing the required format specifier anyway.
* Subsequent patches should unify the dprintf() and zfs_dbgmsg()
functions.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When using zfs to back a Lustre filesystem it's advantageous to
to store a fid with the object id in the directory zap. The only
technical impediment to doing this is that the zpl code expects
a single value in the zap per directory entry.
This change relaxes that requirement such that multiple entries
are allowed provided the first one is the object id. The zpl
code will just ignore additional entries. This allows the ZoL
count to mount datasets which are being used as Lustre server
backends.
Once the upstream feature flags support is merged in this change
should be updated to a read-only feature. Until this occurs
other zfs implementations will not be able to read the zfs
filesystems created by Lustre.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Export the zfs_attr_table symbol so it may be used by non-zpl
consumers which are still interested in writing a zpl compatible
dataset (e.g. Lustre).
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Testing has shown that tq->tq_lock can be highly contended when a
large number of small work items are dispatched. The lock hold time
is reduced by the following changes:
1) Use exclusive threads in the work_waitq
When a single work item is dispatched we only need to wake a single
thread to service it. The current implementation uses non-exclusive
threads so all threads are woken when the dispatcher calls wake_up().
If a large number of threads are in the queue this overhead can become
non-negligible.
2) Conditionally add/remove threads from work waitq
Taskq threads need only add themselves to the work wait queue if
there are no pending work items.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #32
This reverts commit ec2b41049f.
A race condition was introduced by which a wake_up() call can be lost
after the taskq thread determines there is no pending work items,
leading to deadlock:
1. taksq thread enables interrupts
2. dispatcher thread runs, queues work item, call wake_up()
3. taskq thread runs, adds self to waitq, sleeps
This could easily happen if an interrupt for an IO completion was
outstanding at the point where the taskq thread reenables interrupts,
just before the call to add_wait_queue_exclusive(). The handler would
run immediately within the race window.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #32
Since the zpios and potentially other ZFS tests use the
DMU_OST_OTHER type to label their datasets, the zpool and
zfs commands should gracefully handle this type when it is
encountered. This patch modifies the commands' behavior
to ignore any datasets with a dds_type of DMU_OST_OTHER.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#536
This change updates the rpm spec files to have strictly correct
package dependencies. That means a few things:
* The zfs-modules package is now tied to a specific build of
the spl-modules packages based on the kernel version. This
ensures that the correct spl-modules packages will always get
installed and not just the newest.
* The zfs package now requires both the zfs-modules and spl
packages. Thus a 'yum install zfs' will pull in the minimal
set of packages required for a functional system.
* The zfs-devel packages now require the zfs package to be
installed which is normal behavior for -devel packages.
* Remove the redundant distribution release extension. This
is already added once because it is part of the kernel package
release name.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When the original build system code was added the release
component was accidentally omited from the development header
install path. This patch adds the missing path component so
it's always clear exactly what release your compiling against.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This change updates the rpm spec files to have strictly correct
package dependencies. That means a few things:
* Add a dependency to the spl package for the spl-modules package.
This ensures that when running 'yum install spl' that newest
version of the spl-modules will be installed.
* Remove the redundant distribution release extension. This
is already added once because it is part of the kernel package
release name.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When the original build system code was added the release
component was accidentally omited from the development header
install path. This patch adds the missing path component so
it's always clear exactly what release your compiling against.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Commit zfsonlinux/zfs@57a4eddc4d
allows the bootfs property to be set on any pool, but does not
accommodate subsequent vdev changes. For example:
# zpool replace rpool /dev/sda /dev/sdb
operation not supported on this type of pool
property 'bootfs' is not supported on EFI labeled devices
For non-Solaris builds, disable the check that emits this error.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Testing has shown that tq->tq_lock can be highly contended when a
large number of small work items are dispatched. The lock hold time
is reduced by the following changes:
1) Use exclusive threads in the work_waitq
When a single work item is dispatched we only need to wake a single
thread to service it. The current implementation uses non-exclusive
threads so all threads are woken when the dispatcher calls wake_up().
If a large number of threads are in the queue this overhead can become
non-negligible.
2) Conditionally add/remove threads from work waitq outside of tq_lock
Taskq threads need only add themselves to the work wait queue if there
are no pending work items. Furthermore, the add and remove function
calls can be made outside of the taskq lock since the wait queues are
protected from concurrent access by their own spinlocks.
3) Call wake_up() outside of tq->tq_lock
Again, the wait queues are protected by their own spinlock, so the
dispatcher functions can drop tq->tq_lock before calling wake_up().
A new splat test taskq:contention was added in a prior commit to measure
the impact of these changes. The following table summarizes the
results using data from the kernel lock profiler.
tq_lock time %diff Wall clock (s) %diff
original: 39117614.10 0 41.72 0
exclusive threads: 31871483.61 18.5 34.2 18.0
unlocked add/rm waitq: 13794303.90 64.7 16.17 61.2
unlocked wake_up(): 1589172.08 95.9 16.61 60.2
Each row reflects the average result over 5 test runs.
/proc/lock_stats was zeroed out before and collected after each run.
Column 1 is the cumulative hold time in microseconds for tq->tq_lock.
The tests are cumulative; each row reflects the code changes of the
previous rows. %diff is calculated with respect to "original" as
100*(orig-new)/orig.
Although calling wake_up() outside of the taskq lock dramatically
reduced the taskq lock hold time, the test actually took slightly more
wall clock time. This is because the point of contention shifts from
the taskq lock to the wait queue lock. But the change still seems
worthwhile since it removes our taskq implementation as a bottleneck,
assuming the small increase in wall clock time to be statistical
noise.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#32
Add a test designed to generate contention on the taskq spinlock by
using a large number of threads (100) to perform a large number (131072)
of trivial work items from a single queue. This simulates conditions
that may occur with the zio free taskq when a 1TB file is removed from a
ZFS filesystem, for example. This test should always pass. Its purpose
is to provide a benchmark to easily measure the effectiveness of taskq
optimizations using statistics from the kernel lock profiler.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #32
These libraries, which are an artifact of the ZoL development
process, conflict with packages that are already in distribution:
* libspl: SPL Programming Language
* libavl: AVL for Linux
* libefi: GRUB
And these libraries are potential conflicts:
* libshare: the Linux Mount Manager
* libunicode: Perl and Python
Recompose these five ZoL components into the four libraries that are
conventionally provided by Solaris and FreeBSD systems:
+ libnvpair
+ libuutil
+ libzpool
+ libzfs
This change resolves the name conflict, makes ZoL more compatible
with existing software that uses autotools to detect ZFS, and allows
pkg-zfs to better reflect the official Debian kFreeBSD packaging.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #430
The vdev_is_bootable() restrictions are no longer necessary
with recent GRUB2 code. FreeBSD has implemented the same
change, except that I moved the Solaris comment to be inside
the #ifdef __sun__ block.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #317
Apply the same fix to SPL that was applied to ZFS earlier at:
zfsonlinux/zfs@d433c20651
Additionally quote @LINUX_SYMBOLS@ because it is a null substitution
in this configuration, which results in a `[ -f ]` expression that
incorrectly evaluates to true.
# ./configure --with-config=user
# make distclean
Making distclean in module
make[1]: Entering directory `/spl/module'
make -C SUBDIRS=`pwd` clean
make: Entering an unknown directory
make: *** SUBDIRS=/spl/module: No such file or directory. Stop.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
As described in Issue #458 and #258, unlinking large amounts of data
can cause the threads in the zio free wait queue to start spinning.
Reducing the number of z_fr_iss threads from a fixed value of 100 to 1
per cpu signficantly reduces contention on the taskq spinlock and
improves throughput.
Instrumenting the taskq code showed that __taskq_dispatch() can spend
a long time holding tq->tq_lock if there are a large number of threads
in the queue. It turns out the time spent in wake_up() scales
linearly with the number of threads in the queue. When a large number
of short work items are dispatched, as seems to be the case with
unlink, the worker threads drain the queue faster than the dispatcher
can fill it. They then all pile into the work wait queue to wait for
new work items. So if 100 threads are in the queue, wake_up() takes
about 100 times as long, and the woken threads have to spin until the
dispatcher releases the lock.
Reducing the number of threads helps with the symptoms, but doesn't
get to the root of the problem. It would seem that wake_up()
shouldn't scale linearly in time with queue depth, particularly if we
are only trying to wake up one thread. In that vein, I tried making
all of the waiting processes exclusive to prevent the scheduler from
iterating over the entire list, but I still saw the linear time
scaling. So further investigation is needed, but in the meantime
reducing the thread count is an easy workaround.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #258
Issue #458
Originally, the per-file link limit was set to 65536 because the
exact Linux VFS limit was unclear. Internally ZFS is able to
support 64-bit link counts. After a more careful investigation
the limit can be safely raised to 2^31-1.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#514
Unfortunately, Arch's package manager `pacman` shares it's name with a
popular arcade video game. Thus, in order to refrain from executing the
video game when we mean to execute the package manager, SPL_AC_PACMAN is
now only run when $VENDOR is determined to be "arch".
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closeszfsonlinux/zfs#517
Unfortunately, Arch's package manager `pacman` shares it's name with a
popular arcade video game. Thus, in order to refrain from executing the
video game when we mean to execute the package manager, ZFS_AC_PACMAN is
now only run when $VENDOR is determined to be "arch".
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#517
Linux supports mounting over non-empty directories by default.
In Solaris this is not the case and -O option is required for
zfs mount to mount a zfs filesystem over a non-empty directory.
For compatibility, I've added support for -O option to mount
zfs filesystems over non-empty directories if the user wants
to, just like in Solaris.
I've defined MS_OVERLAY to record it in the flags variable if
the -O option is supplied. The flags variable passes through
a few functions and its checked before performing the empty
directory check in zfs_mount function. If -O is given, the
check is not performed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#473
Make the indenting in the zpl_xattr.c file consistent with the Sun
coding standard by removing soft tabs.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The security_inode_init_security() API has been changed to include
a filesystem specific callback to write security extended attributes.
This was done to support the initialization of multiple LSM xattrs
and the EVM xattr.
This change updates the code to use the new API when it's available.
Otherwise it falls back to the previous implementation.
In addition, the ZFS_AC_KERNEL_6ARGS_SECURITY_INODE_INIT_SECURITY
autoconf test has been made more rigerous by passing the expected
types. This is done to ensure we always properly the detect the
correct form for the security_inode_init_security() API.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#516
The wait_lock member of the rw_semaphore struct became a raw_spinlock_t
in Linux 3.2 at torvalds/linux@ddb6c9b58a.
Wrap spin_lock_* function calls in a new spl_rwsem_* interface to
ensure type safety if raw_spinlock_t becomes architecture specific,
and to satisfy these compiler warnings:
warning: passing argument 1 of ‘spinlock_check’
from incompatible pointer type [enabled by default]
note: expected ‘struct spinlock_t *’
but argument is of type ‘struct raw_spinlock_t *’
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #76Closes: zfsonlinux/zfs#463
Some implementations of `awk` incorrectly parse the \< and \> regex
symbols, so use a `while read` loop and regular globbing instead.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #259
The Linux 3.1 kernel has introduced the concept of per-filesystem
shrinkers which are directly assoicated with a super block. Prior
to this change there was one shared global shrinker.
The zfs code relied on being able to call the global shrinker when
the arc_meta_limit was exceeded. This would cause the VFS to drop
references on a fraction of the dentries in the dcache. The ARC
could then safely reclaim the memory used by these entries and
honor the arc_meta_limit. Unfortunately, when per-filesystem
shrinkers were added the old interfaces were made unavailable.
This change adds support to use the new per-filesystem shrinker
interface so we can continue to honor the arc_meta_limit. The
major benefit of the new interface is that we can now target
only the zfs filesystem for dentry and inode pruning. Thus we
can minimize any impact on the caching of other filesystems.
In the context of making this change several other important
issues related to managing the ARC were addressed, they include:
* The dnlc_reduce_cache() function which was called by the ARC
to drop dentries for the Posix layer was replaced with a generic
zfs_prune_t callback. The ZPL layer now registers a callback to
drop these dentries removing a layering violation which dates
back to the Solaris code. This callback can also be used by
other ARC consumers such as Lustre.
arc_add_prune_callback()
arc_remove_prune_callback()
* The arc_reduce_dnlc_percent module option has been changed to
arc_meta_prune for clarity. The dnlc functions are specific to
Solaris's VFS and have already been largely eliminated already.
The replacement tunable now represents the number of bytes the
prune callback will request when invoked.
* Less aggressively invoke the prune callback. We used to call
this whenever we exceeded the arc_meta_limit however that's not
strictly correct since it results in over zeleous reclaim of
dentries and inodes. It is now only called once the arc_meta_limit
is exceeded and every effort has been made to evict other data from
the ARC cache.
* More promptly manage exceeding the arc_meta_limit. When reading
meta data in to the cache if a buffer was unable to be recycled
notify the arc_reclaim thread to invoke the required prune.
* Added arcstat_prune kstat which is incremented when the ARC
is forced to request that a consumer prune its cache. Remember
this will only occur when the ARC has no other choice. If it
can evict buffers safely without invoking the prune callback
it will.
* This change is also expected to resolve the unexpect collapses
of the ARC cache. This would occur because when exceeded just the
arc_meta_limit reclaim presure would be excerted on the arc_c
value via arc_shrink(). This effectively shrunk the entire cache
when really we just needed to reclaim meta data.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#466Closes#292
The Proxmox VE kernel contains a patch which renames the function
invalidate_inodes() to invalidate_inodes_check(). In the process
it adds a 'check' argument and a '#define invalidate_inodes(x)'
compatibility wrapper for legacy callers. Therefore, if either
of these functions are exported invalidate_inodes() can be
safely used.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#58
If the lsb-release package is installed on an Arch Linux distribution,
the configure step will incorrectly detect the running distribution as
Ubuntu. This is a result of both distributions providing an
/etc/lsb-release file, and the Ubuntu VENDOR check being performed
first.
Since the Arch Linux test check's for a file more specific to the Arch
Linux distribution, moving Arch Linux's VENDOR check above Unbuntu's
check provides a quick and easy solution.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
If the lsb-release package is installed on an Arch Linux distribution,
the configure step will incorrectly detect the running distribution as
Ubuntu. This is a result of both distributions providing an
/etc/lsb-release file, and the Ubuntu VENDOR check being performed
first.
Since the Arch Linux test check's for a file more specific to the Arch
Linux distribution, moving Arch Linux's VENDOR check above Unbuntu's
check provides a quick and easy solution.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#72
Regenerating the autotools configuration on Debian and Ubuntu systems
causes compilation to fail with this error message:
cmd/mount_zfs/../../cmd/mount_zfs/mount_zfs.c:403:
undefined reference to `is_selinux_enabled'
In the automake template, set "mount_zfs_LDFLAGS = ... $(LIBSELINUX)"
so that the /sbin/mount.zfs utility is linked to libselinux.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Directly changing inode->i_nlink is deprecated in Linux 3.2 by commit
SHA: bfe8684869601dacfcb2cd69ef8cfd9045f62170
Use the new set_nlink() kernel function instead.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #462
Richard Yao
Turbo Fredriksson
Brian Behlendorf
Etienne Dechamps
Etienne Dechamps
Darik Horn
Ned Bass
Prakash Surya
Richard Laager
Suman Chakravartula