Commit Graph

5820 Commits

Author SHA1 Message Date
Darik Horn b97f368d04 Avoid using awk in the zpool_id script.
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
2012-01-11 11:56:56 -08:00
Brian Behlendorf ab26409db7 Linux 3.1 compat, super_block->s_shrink
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 #466
Closes #292
2012-01-11 11:46:02 -08:00
Brian Behlendorf 5f6c14b1ed Proxmox VE kernel compat, invalidate_inodes()
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
2011-12-21 14:29:45 -08:00
Prakash Surya 8eaa020b46 Move Arch Linux's VENDOR check above Ubuntu's
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>
2011-12-19 12:05:10 -08:00
Prakash Surya cd2817f8a6 Move Arch Linux's VENDOR check above Ubuntu's
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
2011-12-19 12:03:40 -08:00
Darik Horn afd7da0ce7 Add LIBSELINUX to mount_zfs_LDFLAGS.
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>
2011-12-16 20:04:42 -08:00
Darik Horn 28eb9213d8 Linux 3.2 compat: set_nlink()
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
2011-12-16 20:02:52 -08:00
Prakash Surya 8f2503e0af Store copy of tqent_flags prior to servicing task
A preallocated taskq_ent_t's tqent_flags must be checked prior to
servicing the taskq_ent_t. Once a preallocated taskq entry is serviced,
the ownership of the entry is handed back to the caller of
taskq_dispatch, thus the entry's contents can potentially be mangled.

In particular, this is a problem in the case where a preallocated taskq
entry is serviced, and the caller clears it's tqent_flags field. Thus,
when the function returns and task_done is called, it looks as though
the entry is **not** a preallocated task (when in fact it **is** a
preallocated task).

In this situation, task_done will place the preallocated taskq_ent_t
structure onto the taskq_t's free list. This is a **huge** mistake. If
the taskq_ent_t is then freed by the caller of taskq_dispatch, the
taskq_t's free list will hold a pointer to garbage data. Even worse, if
nothing has over written the freed memory before the pointer is
dereferenced, it may still look as though it points to a valid list_head
belonging to a taskq_ent_t structure.

Thus, the task entry's flags are now copied prior to servicing the task.
This copy is then checked to see if it is a preallocated task, and
determine if the entry needs to be passed down to the task_done
function.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #71
2011-12-16 16:54:00 -08:00
Darik Horn e6101ea87f Update the character class in the zpool man page.
ZoL and all Solaris derivatives allow pool names to contain the colon
and space characters. Update the man page to reflect current behavior.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #438
2011-12-16 14:00:38 -08:00
Prakash Surya e7e5f78e7b Swap taskq_ent_t with taskqid_t in taskq_thread_t
The taskq_t's active thread list is sorted based on its
tqt_ent->tqent_id field. The list is kept sorted solely by inserting
new taskq_thread_t's in their correct sorted location; no other
means is used. This means that once inserted, if a taskq_thread_t's
tqt_ent->tqent_id field changes, the list runs the risk of no
longer being sorted.

Prior to the introduction of the taskq_dispatch_prealloc() interface,
this was not a problem as a taskq_ent_t actively being serviced under
the old interface should always have a static tqent_id field. Thus,
once the taskq_thread_t is added to the taskq_t's active thread list,
the taskq_thread_t's tqt_ent->tqent_id field would remain constant.

Now, this is no longer the case. Currently, if using the
taskq_dispatch_prealloc() interface, any given taskq_ent_t actively
being serviced _may_ have its tqent_id value incremented. This happens
when the preallocated taskq_ent_t structure is recursively dispatched.
Thus, a taskq_thread_t could potentially have its tqt_ent->tqent_id
field silently modified from under its feet. If this were to happen
to a taskq_thread_t on a taskq_t's active thread list, this would
compromise the integrity of the order of the list (as the list
_may_ no longer be sorted).

To get around this, the taskq_thread_t's taskq_ent_t pointer was
replaced with its own static copy of the tqent_id. So, as a taskq_ent_t
is pulled off of the taskq_t's pending list, a static copy of its
tqent_id is made and this copy is used to sort the active thread
list. Using a static copy is key in ensuring the integrity of the
order of the active thread list. Even if the underlying taskq_ent_t
is recursively dispatched (as has its tqent_id modified), this
static copy stored inside the taskq_thread_t will remain constant.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #71
2011-12-16 13:26:54 -08:00
Prakash Surya 6ba3b44614 Add make rule for building Arch Linux packages
Added the necessary build infrastructure for building packages
compatible with the Arch Linux distribution. As such, one can now run:

    $ ./configure
    $ make pkg     # Alternatively, one can run 'make arch' as well

on the Arch Linux machine to create two binary packages compatible with
the pacman package manager, one for the zfs userland utilities and
another for the zfs kernel modules. The new packages can then be
installed by running:

    # pacman -U $package.pkg.tar.xz

In addition, source-only packages suitable for an Arch Linux chroot
environment or remote builder can also be build using the 'sarch' make
rule.

NOTE: Since the source dist tarball is created on the fly from the head
of the build tree, it's MD5 hash signature will be continually influx.
As a result, the md5sum variable was intentionally omitted from the
PKGBUILD files, and the '--skipinteg' makepkg option is used. This may
or may not have any serious security implications, as the source tarball
is not being downloaded from an outside source.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #491
2011-12-14 19:14:23 -08:00
Prakash Surya c2dceb5cd5 Add make rule for building Arch Linux packages
Added the necessary build infrastructure for building packages
compatible with the Arch Linux distribution. As such, one can now run:

    $ ./configure
    $ make pkg     # Alternatively, one can run 'make arch' as well

on an Arch Linux machine to create two binary packages compatible with
the pacman package manager, one for the spl userland utilties and
another for the spl kernel modules. The new packages can then be
installed by running:

    # pacman -U $package.pkg.tar.xz

In addition, source-only packages suitable for an Arch Linux chroot
environment or remote builder can also be built using the 'sarch' make
rule.

NOTE: Since the source dist tarball is created on the fly from the head
of the build tree, it's MD5 hash signature will be continually influx.
As a result, the md5sum variable was intentionally omitted from the
PKGBUILD files, and the '--skipinteg' makepkg option is used. This may
or may not have any serious security implications, as the source tarball
is not being downloaded from an outside source.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #68
2011-12-14 16:44:10 -08:00
Garrett D'Amore a38718a63d Illumos #734: Use taskq_dispatch_ent() interface
It has been observed that some of the hottest locks are those
of the zio taskqs.  Contention on these locks can limit the
rate at which zios are dispatched which limits performance.

This upstream change from Illumos uses new interface to the
taskqs which allow them to utilize a prealloc'ed taskq_ent_t.
This removes the need to perform an allocation at dispatch
time while holding the contended lock.  This has the effect
of improving system performance.

Reviewed by: Albert Lee <trisk@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Alexey Zaytsev <alexey.zaytsev@nexenta.com>
Reviewed by: Jason Brian King <jason.brian.king@gmail.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References to Illumos issue:
  https://www.illumos.org/issues/734

Ported-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #482
2011-12-14 09:19:30 -08:00
Prakash Surya 699d5ee8a9 Exercise new taskq interface in splat-taskq tests
The splat-taskq test functions were slightly modified to exercise
the new taskq interface in addition to the old interface.  If the
old interface passes each of its tests, the new interface is
exercised.  Both sub tests (old interface and new interface) must
pass for each test as a whole to pass.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #65
2011-12-13 16:10:57 -08:00
Prakash Surya 44217f7aad Implement taskq_dispatch_prealloc() interface
This patch implements the taskq_dispatch_prealloc() interface which
was introduced by the following illumos-gate commit.  It allows for
a preallocated taskq_ent_t to be used when dispatching items to a
taskq.  This eliminates a memory allocation which helps minimize
lock contention in the taskq when dispatching functions.

    commit 5aeb94743e3be0c51e86f73096334611ae3a058e
    Author: Garrett D'Amore <garrett@nexenta.com>
    Date:   Wed Jul 27 07:13:44 2011 -0700

    734 taskq_dispatch_prealloc() desired
    943 zio_interrupt ends up calling taskq_dispatch with TQ_SLEEP

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #65
2011-12-13 16:10:57 -08:00
Prakash Surya ac1e5b6033 Add Test: "Single task queue, recursive dispatch"
Added another splat taskq test to ensure tasks can be recursively
submitted to a single task queue without issue. When the
taskq_dispatch_prealloc() interface is introduced, this use case
can potentially cause a deadlock if a taskq_ent_t is dispatched
while its tqent_list field is not empty. This _should_ never be
a problem with the existing taskq_dispatch() interface.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #65
2011-12-13 16:10:57 -08:00
Prakash Surya 2c02b71b14 Replace tq_work_list and tq_threads in taskq_t
To lay the ground work for introducing the taskq_dispatch_prealloc()
interface, the tq_work_list and tq_threads fields had to be replaced
with new alternatives in the taskq_t structure.

The tq_threads field was replaced with tq_thread_list. Rather than
storing the pointers to the taskq's kernel threads in an array, they are
now stored as a list. In addition to laying the ground work for the
taskq_dispatch_prealloc() interface, this change could also enable taskq
threads to be dynamically created and destroyed as threads can now be
added and removed to this list relatively easily.

The tq_work_list field was replaced with tq_active_list. Instead of
keeping a list of taskq_ent_t's which are currently being serviced, a
list of taskq_threads currently servicing a taskq_ent_t is kept. This
frees up the taskq_ent_t's tqent_list field when it is being serviced
(i.e. now when a taskq_ent_t is being serviced, it's tqent_list field
will be empty).

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #65
2011-12-13 16:10:50 -08:00
Prakash Surya 046a70c93b Replace struct spl_task with struct taskq_ent
The spl_task structure was renamed to taskq_ent, and all of
its fields were renamed to have a prefix of 'tqent' rather
than 't'. This was to align with the naming convention which
the ZFS code assumes.  Previously these fields were private
so the name never mattered.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #65
2011-12-13 12:28:09 -08:00
Prakash Surya ed948fa72b Add SPLAT_TEST_FINI call for SPLAT_TASKQ_TEST6_ID
This change adds the neglected SPLAT_TEST_FINI call for the
SPLAT_TASKQ_TEST6_ID, just as is done for the other 5 SPLAT_TASKQ_*
tests.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #64
2011-12-13 12:26:16 -08:00
Prakash Surya 93806f58a6 Fix usage of MUTEX macro in mutex_enter_nested
A call site of the MUTEX macro had incorrectly placed its closing
parenthesis, causing two parameters to be passed rather than one. This
change moves the misplaced parenthesis to fix the typographical error.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #70
2011-12-13 11:04:21 -08:00
Chris Dunlop 791dc876eb Allow 64-bit timestamps to be set on 64-bit kernels
ZFS and 64-bit linux are perfectly capable of dealing with 64-bit
timestamps, but ZFS deliberately prevents setting them.  Adjust
the SPL such that TIMESPEC_OVERFLOW will not always assume 32-bit
values and instead use the correct values for your kernel build.
This effectively allows 64-bit timestamps on 64-bit systems.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes ZFS issue #487
2011-12-12 11:06:03 -08:00
Brian Behlendorf 30a9524e45 Set zvol_major/zvol_threads permissions
The zvol_major and zvol_threads module options were being created
with 0 permission bits.  This prevented them from being listed in
the /sys/module/zfs/parameters/ directory, although they were
visible in `modinfo zfs`.  This patch fixes the issue by updating
the permission bits to 0444.  For the moment these options must
be read-only because they are used during module initialization.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #392
2011-12-07 09:27:50 -08:00
Brian Behlendorf 23bdb07d4e Update default ARC memory limits
In the upstream OpenSolaris ZFS code the maximum ARC usage is
limited to 3/4 of memory or all but 1GB, whichever is larger.
Because of how Linux's VM subsystem is organized these defaults
have proven to be too large which can lead to stability issues.

To avoid making everyone manually tune the ARC the defaults are
being changed to 1/2 of memory or all but 4GB.  The rational for
this is as follows:

* Desktop Systems (less than 8GB of memory)

  Limiting the ARC to 1/2 of memory is desirable for desktop
  systems which have highly dynamic memory requirements.  For
  example, launching your web browser can suddenly result in a
  demand for several gigabytes of memory.  This memory must be
  reclaimed from the ARC cache which can take some time.  The
  user will experience this reclaim time as a sluggish system
  with poor interactive performance.  Thus in this case it is
  preferable to leave the memory as free and available for
  immediate use.

* Server Systems (more than 8GB of memory)

  Using all but 4GB of memory for the ARC is preferable for
  server systems.  These systems often run with minimal user
  interaction and have long running daemons with relatively
  stable memory demands.  These systems will benefit most by
  having as much data cached in memory as possible.

These values should work well for most configurations.  However,
if you have a desktop system with more than 8GB of memory you may
wish to further restrict the ARC.  This can still be accomplished
by setting the 'zfs_arc_max' module option.

Additionally, keep in mind these aren't currently hard limits.
The ARC is based on a slab implementation which can suffer from
memory fragmentation.  Because this fragmentation is not visible
from the ARC it may believe it is within the specified limits while
actually consuming slightly more memory.  How much more memory get's
consumed will be determined by how badly fragmented the slabs are.

In the long term this can be mitigated by slab defragmentation code
which was OpenSolaris solution.  Or preferably, using the page cache
to back the ARC under Linux would be even better.  See issue #75
for the benefits of more tightly integrating with the page cache.

This change also fixes a issue where the default ARC max was being
set incorrectly for machines with less than 2GB of memory.  The
constant in the arc_c_max comparison must be explicitly cast to
a uint64_t type to prevent overflow and the wrong conditional
branch being taken.  This failure was typically observed in VMs
which are commonly created with less than 2GB of memory.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #75
2011-12-05 12:02:12 -08:00
Darik Horn 660cbada0f Quote variables in the zfs.lsb script.
For consistency and safety, quote all variables in the zfs.lsb script.
This protects in the unlikely case that any of the file names contain
whitespace.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #439
2011-12-05 09:51:55 -08:00
Darik Horn c2d9c41d50 Source /etc/default/zfs after setting defaults.
Let the administrator override all script variables by sourcing the
/etc/default/zfs file after the default values are set.

The spelling mistake in the old path name makes it unlikely that this
bug affected any users.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #371
2011-12-05 09:51:20 -08:00
Darik Horn db7c1771da Demote the whackbang in the zpool_id script.
The zpool_id script is posixly correct and does not use bash
features, so change its whackbang from /bin/bash to /bin/sh.

Debian policy also stipulates that system scripts be dash compatible.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-12-05 09:48:18 -08:00
Darik Horn 87193e2b61 Demote egrep to grep in the zpool_id script.
Direct invocation of GNU egrep is deprecated by its man page, and the
its argument in the zpool_id script is not an extended expression.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-12-05 09:48:01 -08:00
Darik Horn 04bf5ecc1f Quote variables in the zpool_id script.
For consistency and safety, quote all variables in the zpool_id
script. This accomodates a `-c CONFIG` parameter value with
whitespace in the path name.

Also fix a typo in the usage synopsis for `-h`.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #439
2011-12-05 09:47:03 -08:00
Darik Horn 9c8254f6f9 Support path_id changes in udev 174.
The /lib/udev/path_id helper became a builtin command in the udev 174
release, so test whether path_id is external in the zpool_id script.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #429
2011-12-05 09:46:48 -08:00
Gunnar Beutner 590338f63e Added comments for libshare's NFS functions.
Some of the functions' purpose wasn't immediately obvious without
additional explanations. This commit adds these missing comments.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-12-05 09:33:00 -08:00
Prakash Surya b9c59ec83a Fix configure tests to play nice with GCC 4.6
As of GCC 4.6, specific kernel 2.6.32 header files do not compile
cleanly without warnings. One specific example of this is the
arch/x86/include/asm/percpu.h file. Thus, a few of the configure tests
were getting hung up on this and the '-Wno-unsued-but-set-variables'
compile option had to be introduced.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #459
2011-11-29 16:14:25 -08:00
Brian Behlendorf f31b3ebe6e Allow xattrs on symlinks
The Solaris version of ZFS does not allow xattrs to be set on
symlinks due to the way they implemented the attropen() system
call.  Linux however implements xattrs through the lgetxattr()
and lsetxattr() system calls which do not have this limitation.

The only reason this hasn't always worked under ZFS on Linux
is that the xattr handlers were not registered for symlink type
inodes.  This was done simply to be consistent with the Solaris
behavior.

Upon futher reflection I believe this should be allowed under
Linux.  The only ill effect would be that the xattrs on symlinks
will not be visible when the pool is imported on a Solaris
system.  This also has the benefit that it allows for SELinux
style security xattr labeling which expects to be able to set
xattrs on all inode types.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #272
2011-11-29 10:24:24 -08:00
Brian Behlendorf 82a37189aa Implement SA based xattrs
The current ZFS implementation stores xattrs on disk using a hidden
directory.  In this directory a file name represents the xattr name
and the file contexts are the xattr binary data.  This approach is
very flexible and allows for arbitrarily large xattrs.  However,
it also suffers from a significant performance penalty.  Accessing
a single xattr can requires up to three disk seeks.

  1) Lookup the dnode object.
  2) Lookup the dnodes's xattr directory object.
  3) Lookup the xattr object in the directory.

To avoid this performance penalty Linux filesystems such as ext3
and xfs try to store the xattr as part of the inode on disk.  When
the xattr is to large to store in the inode then a single external
block is allocated for them.  In practice most xattrs are small
and this approach works well.

The addition of System Attributes (SA) to zfs provides us a clean
way to make this optimization.  When the dataset property 'xattr=sa'
is set then xattrs will be preferentially stored as System Attributes.
This allows tiny xattrs (~100 bytes) to be stored with the dnode and
up to 64k of xattrs to be stored in the spill block.  If additional
xattr space is required, which is unlikely under Linux, they will be
stored using the traditional directory approach.

This optimization results in roughly a 3x performance improvement
when accessing xattrs which brings zfs roughly to parity with ext4
and xfs (see table below).  When multiple xattrs are stored per-file
the performance improvements are even greater because all of the
xattrs stored in the spill block will be cached.

However, by default SA based xattrs are disabled in the Linux port
to maximize compatibility with other implementations.  If you do
enable SA based xattrs then they will not be visible on platforms
which do not support this feature.

----------------------------------------------------------------------
   Time in seconds to get/set one xattr of N bytes on 100,000 files
------+--------------------------------+------------------------------
      |            setxattr            |            getxattr
bytes |  ext4     xfs zfs-dir  zfs-sa  |  ext4     xfs zfs-dir  zfs-sa
------+--------------------------------+------------------------------
1     |  2.33   31.88   21.50    4.57  |  2.35    2.64    6.29    2.43
32    |  2.79   30.68   21.98    4.60  |  2.44    2.59    6.78    2.48
256   |  3.25   31.99   21.36    5.92  |  2.32    2.71    6.22    3.14
1024  |  3.30   32.61   22.83    8.45  |  2.40    2.79    6.24    3.27
4096  |  3.57  317.46   22.52   10.73  |  2.78   28.62    6.90    3.94
16384 |   n/a 2342.39   34.30   19.20  |   n/a   45.44  145.90    7.55
65536 |   n/a 2941.39  128.15  131.32* |   n/a  141.92  256.85  262.12*

Legend:
* ext4      - Stock RHEL6.1 ext4 mounted with '-o user_xattr'.
* xfs       - Stock RHEL6.1 xfs mounted with default options.
* zfs-dir   - Directory based xattrs only.
* zfs-sa    - Prefer SAs but spill in to directories as needed, a
              trailing * indicates overflow in to directories occured.

NOTE: Ext4 supports 4096 bytes of xattr name/value pairs per file.
NOTE: XFS and ZFS have no limit on xattr name/value pairs per file.
NOTE: Linux limits individual name/value pairs to 65536 bytes.
NOTE: All setattr/getattr's were done after dropping the cache.
NOTE: All tests were run against a single hard drive.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #443
2011-11-28 15:45:51 -08:00
Prakash Surya e89236fd28 In autoconf v2.68, AC_LANG_PROGRAM must be quoted
This change updates the AC_LANG_PROGRAM autoconf macro invocations to be
wrapped in quotes. As of autoconf version 2.68, the quotes are necessary
to prevent warnings from appearing. Specifically, the autoconf v2.68
Forward Porting Notes specifies:

    It is important to note that you need to ensure that the call to
    AC_LANG_SOURCE is quoted and not expanded, otherwise that will
    cause the warning to appear nonetheless.

Finally, because of the additional quoting we can drop the extra
quotas used by the ZFS_AC_CONFIG_USER_STACK_GUARD autoconf check.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #464
2011-11-28 11:16:33 -08:00
Prakash Surya e05bec805b Fix a typo referencing an incorrect symbol
The splat_taskq_test4_common function was incorrectly referencing
the splat_taskq-test13_func symbol, when it meant to be using the
splat_taskq_test4_func symbol.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #61
2011-11-21 16:52:36 -08:00
Suman Chakravartula ada8ec1ec5 Allow leading digits in userquota/groupquota names
While setting/getting userquota and groupquota properties, the input
was not treated as a possible username or groupname if it had a
leading digit. While useradd in linux recommends the regexp
[a-z_][a-z0-9_-]*[$]? , it is not enforced. This causes problem for
usernames with leading digits in them. We need to be able to support
getting and setting properties for this unconventional but possible
input category

I've updated the code to validate the username or groupname directly
via the API. Also, note that I moved this validation to the beginning
before the check for SID names with @. This also supports usernames
with @ character in them which are valid. Only when input with @ is
not a valid username, it is interpreted as a potential SID name.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #428
2011-11-21 16:29:18 -08:00
Brian Behlendorf ca5fd24984 Limit maximum ashift value to 12
While we initially allowed you to set your ashift as large as 17
(SPA_MAXBLOCKSIZE) that is actually unsafe.  What wasn't considered
at the time is that each uberblock written to the vdev label ring
buffer will be of this size.  Now the buffer is statically sized
to 128k and we need to be able to fit several uberblocks in it.
With a large ashift that becomes a problem.

Therefore I'm reducing the maximum configurable ashift value to 12.
This is large enough for the 4k sector drives and small enough that
we can still keep the most recent 32 uberblock in the vdev label
ring buffer.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #425
2011-11-11 14:50:48 -08:00
Brian Behlendorf 1114ae6ae7 Prepend spl_ to all init/fini functions
This is a bit of cleanup I'd been meaning to get to for a while
to reduce the chance of a type conflict.  Well that conflict
finally occurred with the kstat_init() function which conflicts
with a function in the 2.6.32-6-pve kernel.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #56
2011-11-11 09:18:28 -08:00
Brian Behlendorf 948914d2f1 Fix depmod warning
The depmod utility from module-init-tools 3.12-pre3 generates a
warning when the -e option is used without -E or -F.  This was
observed under OpenSuse 11.4.  To resolve the issue when the
exact System.map-* for your kernel cannot be found fallback to
a generic safe '/sbin/depmod -a'.

  WARNING: -e needs -E or -F

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-11-10 10:36:30 -08:00
Brian Behlendorf 09559cdd15 Fix depmod warning
The depmod utility from module-init-tools 3.12-pre3 generates a
warning when the -e option is used without -E or -F.  This was
observed under OpenSuse 11.4.  To resolve the issue when the
exact System.map-* for your kernel cannot be found fallback to
a generic safe '/sbin/depmod -a'.

  WARNING: -e needs -E or -F

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-11-10 10:26:06 -08:00
Brian Behlendorf adcd70bd1a Linux 3.1 compat, fops->fsync()
The Linux 3.1 kernel updated the fops->fsync() callback yet again.
They now pass the requested range and delegate the responsibility
for calling filemap_write_and_wait_range() to the callback.  In
addition imutex is no longer held by the caller and the callback
is responsible for taking the lock if required.

This commit updates the code to provide a zpl_fsync() function
for the updated API.  Implementations for the previous two APIs
are also maintained for compatibility.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #445
2011-11-10 10:03:08 -08:00
Brian Behlendorf fe71c0e567 Linux 3.1 compat, shrink_*cache_memory
As of Linux 3.1 the shrink_dcache_memory and shrink_icache_memory
functions have been removed.  This same task is now accomplished
more cleanly with per super block shrinkers.  This unfortunately
leaves us no easy way to support the dnlc_reduce_cache() function.

This support has always been entirely optional.  So when no
reasonable interface is available allow the dnlc_reduce_cache()
function to effectively become a no-op.

The downside of this change is that it will prevent the zfs arc
meta data limts from being enforced.  However, the current zfs
implementation in this regard is already flawed and needs to
be reworked.  If the arc needs to enfore a meta data limit it
will need to be extended to coordinate directly with the zpl.
This will allow us to drop all this compatibility code and get
more fine grained control over the cache management.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
2011-11-09 19:36:30 -08:00
Brian Behlendorf 0d0b523728 Linux 3.1 compat, vfs_fsync()
Preferentially use the vfs_fsync() function.  This function was
initially introduced in 2.6.29 and took three arguments.  As
of 2.6.35 the dentry argument was dropped from the function.
For older kernels fall back to using file_fsync() which also
took three arguments including the dentry.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
2011-11-09 19:36:21 -08:00
Brian Behlendorf 12ff95ff57 Linux 3.1 compat, kern_path_parent()
Prior to Linux 3.1 the kern_path_parent symbol was exported for
use by kernel modules.  As of Linux 3.1 it is now longer easily
available.  To handle this case the spl will now dynamically
look up address of the missing symbol at module load time.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
2011-11-09 16:51:25 -08:00
Brian Behlendorf 8c19f5b407 Suppress packaging warning
Only under Ubuntu Lucid the rpm packaging step mistakenly adds
the following files twice to the package because of the /lib
naming convention.  This is harmless but results in a warning
which the buildot flags as a failure.  Suppress this warning.

  warning: File listed twice: /lib/udev/rules.d
  warning: File listed twice: /lib/udev/rules.d/60-zpool.rules
  warning: File listed twice: /lib/udev/rules.d/60-zvol.rules
  warning: File listed twice: /lib/udev/rules.d/90-zfs.rules
  warning: File listed twice: /lib/udev/sas_switch_id
  warning: File listed twice: /lib/udev/zpool_id
  warning: File listed twice: /lib/udev/zvol_id

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-11-08 11:32:04 -08:00
Brian Behlendorf 5547c2f1bf Simplify BDI integration
Update the code to use the bdi_setup_and_register() helper to
simplify the bdi integration code.  The updated code now just
registers the bdi during mount and destroys it during unmount.

The only complication is that for 2.6.32 - 2.6.33 kernels the
helper wasn't available so in these cases the zfs code must
provide it.  Luckily the bdi_setup_and_register() function
is trivial.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #367
2011-11-08 10:19:03 -08:00
Brian Behlendorf 591fb62f19 Disown dataset in zfs_sb_create()
Fix an unlikely failure cause in zfs_sb_create() which could
leave the dataset owned on error and thus unavailable until
after a reboot.  Disown the dataset if SA are expected but
are in fact missing.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2011-11-08 10:18:40 -08:00
Brian Behlendorf ae6ba3dbe6 Improve meta data performance
Profiling the system during meta data intensive workloads such
as creating/removing millions of files, revealed that the system
was cpu bound.  A large fraction of that cpu time was being spent
waiting on the virtual address space spin lock.

It turns out this was caused by certain heavily used kmem_caches
being backed by virtual memory.  By default a kmem_cache will
dynamically determine the type of memory used based on the object
size.  For large objects virtual memory is usually preferable
and for small object physical memory is a better choice.  See
the spl_slab_alloc() function for a longer discussion on this.

However, there is a certain amount of gray area when defining a
'large' object.  For the following caches it turns out they were
just over the line:

  * dnode_cache
  * zio_cache
  * zio_link_cache
  * zio_buf_512_cache
  * zfs_data_buf_512_cache

Now because we know there will be a lot of churn in these caches,
and because we know the slabs will still be reasonably sized.
We can safely request with the KMC_KMEM flag that the caches be
backed with physical memory addresses.  This entirely avoids the
need to serialize on the virtual address space lock.

As a bonus this also reduces our vmalloc usage which will be good
for 32-bit kernels which have a very small virtual address space.
It will also probably be good for interactive performance since
unrelated processes could also block of this same global lock.
Finally, we may see less cpu time being burned in the arc_reclaim
and txg_sync_threads.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #258
2011-11-03 10:19:21 -07:00
Brian Behlendorf 6a95d0b74c Fix NULL deref in balance_pgdat()
Be careful not to unconditionally clear the PF_MEMALLOC bit in
the task structure.  It may have already been set when entering
zpl_putpage() in which case it must remain set on exit.  In
particular the kswapd thread will have PF_MEMALLOC set in
order to prevent it from entering direct reclaim.  By clearing
it we allow the following NULL deref to potentially occur.

  BUG: unable to handle kernel NULL pointer dereference at (null)
  IP: [<ffffffff8109c7ab>] balance_pgdat+0x25b/0x4ff

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #287
2011-11-03 10:15:39 -07:00
Gunnar Beutner a7b125e9a5 Fix a race condition in zfs_getattr_fast()
zfs_getattr_fast() was missing a lock on the ZFS superblock which
could result in zfs_znode_dmu_fini() clearing the zp->z_sa_hdl member
while zfs_getattr_fast() was accessing the znode. The result of this
would usually be a panic.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fixes #431
2011-11-03 10:13:09 -07:00