Commit Graph

14 Commits

Author SHA1 Message Date
George Wilson
93cf20764a Illumos #4101, #4102, #4103, #4105, #4106
4101 metaslab_debug should allow for fine-grained control
4102 space_maps should store more information about themselves
4103 space map object blocksize should be increased
4105 removing a mirrored log device results in a leaked object
4106 asynchronously load metaslab
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <seb@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

Prior to this patch, space_maps were preferred solely based on the
amount of free space left in each. Unfortunately, this heuristic didn't
contain any information about the make-up of that free space, which
meant we could keep preferring and loading a highly fragmented space map
that wouldn't actually have enough contiguous space to satisfy the
allocation; then unloading that space_map and repeating the process.

This change modifies the space_map's to store additional information
about the contiguous space in the space_map, so that we can use this
information to make a better decision about which space_map to load.
This requires reallocating all space_map objects to increase their
bonus buffer size sizes enough to fit the new metadata.

The above feature can be enabled via a new feature flag introduced by
this change: com.delphix:spacemap_histogram

In addition to the above, this patch allows the space_map block size to
be increase. Currently the block size is set to be 4K in size, which has
certain implications including the following:

    * 4K sector devices will not see any compression benefit
    * large space_maps require more metadata on-disk
    * large space_maps require more time to load (typically random reads)

Now the space_map block size can adjust as needed up to the maximum size
set via the space_map_max_blksz variable.

A bug was fixed which resulted in potentially leaking an object when
removing a mirrored log device. The previous logic for vdev_remove() did
not deal with removing top-level vdevs that are interior vdevs (i.e.
mirror) correctly. The problem would occur when removing a mirrored log
device, and result in the DTL space map object being leaked; because
top-level vdevs don't have DTL space map objects associated with them.

References:
  https://www.illumos.org/issues/4101
  https://www.illumos.org/issues/4102
  https://www.illumos.org/issues/4103
  https://www.illumos.org/issues/4105
  https://www.illumos.org/issues/4106
  https://github.com/illumos/illumos-gate/commit/0713e23

Porting notes:

A handful of kmem_alloc() calls were converted to kmem_zalloc(). Also,
the KM_PUSHPAGE and TQ_PUSHPAGE flags were used as necessary.

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2488
2014-07-22 09:39:16 -07:00
Brian Behlendorf
e0b0ca983d Add visibility in to cached dbufs
Currently there is no mechanism to inspect which dbufs are being
cached by the system.  There are some coarse counters in arcstats
by they only give a rough idea of what's being cached.  This patch
aims to improve the current situation by adding a new dbufs kstat.

When read this new kstat will walk all cached dbufs linked in to
the dbuf_hash.  For each dbuf it will dump detailed information
about the buffer.  It will also dump additional information about
the referenced arc buffer and its related dnode.  This provides a
more complete view in to exactly what is being cached.

With this generic infrastructure in place utilities can be written
to post-process the data to understand exactly how the caching is
working.  For example, the data could be processed to show a list
of all cached dnodes and how much space they're consuming.  Or a
similar list could be generated based on dnode type.  Many other
ways to interpret the data exist based on what kinds of questions
you're trying to answer.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
2013-10-25 13:59:40 -07:00
Prakash Surya
1421c89142 Add visibility in to arc_read
This change is an attempt to add visibility into the arc_read calls
occurring on a system, in real time. To do this, a list was added to the
in memory SPA data structure for a pool, with each element on the list
corresponding to a call to arc_read. These entries are then exported
through the kstat interface, which can then be interpreted in userspace.

For each arc_read call, the following information is exported:

 * A unique identifier (uint64_t)
 * The time the entry was added to the list (hrtime_t)
   (*not* wall clock time; relative to the other entries on the list)
 * The objset ID (uint64_t)
 * The object number (uint64_t)
 * The indirection level (uint64_t)
 * The block ID (uint64_t)
 * The name of the function originating the arc_read call (char[24])
 * The arc_flags from the arc_read call (uint32_t)
 * The PID of the reading thread (pid_t)
 * The command or name of thread originating read (char[16])

From this exported information one can see, in real time, exactly what
is being read, what function is generating the read, and whether or not
the read was found to be already cached.

There is still some work to be done, but this should serve as a good
starting point.

Specifically, dbuf_read's are not accounted for in the currently
exported information. Thus, a follow up patch should probably be added
to export these calls that never call into arc_read (they only hit the
dbuf hash table). In addition, it might be nice to create a utility
similar to "arcstat.py" to digest the exported information and display
it in a more readable format. Or perhaps, log the information and allow
for it to be "replayed" at a later time.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-10-25 13:57:25 -07:00
Matthew Ahrens
13fe019870 Illumos #3464
3464 zfs synctask code needs restructuring
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/3464
  illumos/illumos-gate@3b2aab1880

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1495
2013-09-04 16:01:24 -07:00
Eric Dillmann
9759c60f1a Illumos #3035 LZ4 compression support in ZFS and GRUB
3035 LZ4 compression support in ZFS and GRUB

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Christopher Siden <csiden@delphix.com>

References:
  illumos/illumos-gate@a6f561b4ae
  https://www.illumos.org/issues/3035
  http://wiki.illumos.org/display/illumos/LZ4+Compression+In+ZFS

This patch has been slightly modified from the upstream Illumos
version to be compatible with Linux.  Due to the very limited
stack space in the kernel a lz4 workspace kmem cache is used.
Since we are using gcc we are also able to take advantage of the
gcc optimized __builtin_ctz functions.

Support for GRUB has been dropped from this patch.  That code
is available but those changes will need to made to the upstream
GRUB package.

Lastly, several hunks of dead code were dropped for clarity.  They
include the functions real_LZ4_uncompress(), LZ4_compressBound()
and the Visual Studio specific hunks wrapped in _MSC_VER.

Ported-by: Eric Dillmann <eric@jave.fr>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1217
2013-01-29 09:28:20 -08:00
Christopher Siden
9ae529ec5d Illumos #2619 and #2747
2619 asynchronous destruction of ZFS file systems
2747 SPA versioning with zfs feature flags
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>

References:
  illumos/illumos-gate@53089ab7c8
  illumos/illumos-gate@ad135b5d64
  illumos changeset: 13700:2889e2596bd6
  https://www.illumos.org/issues/2619
  https://www.illumos.org/issues/2747

NOTE: The grub specific changes were not ported.  This change
must be made to the Linux grub packages.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-08 10:35:35 -08:00
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
Brian Behlendorf
ebe7e575ea Add .zfs control directory
Add support for the .zfs control directory.  This was accomplished
by leveraging as much of the existing ZFS infrastructure as posible
and updating it for Linux as required.  The bulk of the core
functionality is now all there with the following limitations.

*) The .zfs/snapshot directory automount support requires a 2.6.37
   or newer kernel.  The exception is RHEL6.2 which has backported
   the d_automount patches.

*) Creating/destroying/renaming snapshots with mkdir/rmdir/mv
   in the .zfs/snapshot directory works as expected.  However,
   this functionality is only available to root until zfs
   delegations are finished.

      * mkdir - create a snapshot
      * rmdir - destroy a snapshot
      * mv    - rename a snapshot

The following issues are known defeciences, but we expect them to
be addressed by future commits.

*) Add automount support for kernels older the 2.6.37.  This should
   be possible using follow_link() which is what Linux did before.

*) Accessing the .zfs/snapshot directory via NFS is not yet possible.
   The majority of the ground work for this is complete.  However,
   finishing this work will require resolving some lingering
   integration issues with the Linux NFS kernel server.

*) The .zfs/shares directory exists but no futher smb functionality
   has yet been implemented.

Contributions-by: Rohan Puri <rohan.puri15@gmail.com>
Contributiobs-by: Andrew Barnes <barnes333@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #173
2012-03-22 13:03:47 -07:00
Gunnar Beutner
055656d4f4 Implemented NFS export_operations.
Implemented the required NFS operations for exporting ZFS datasets
using the in-kernel NFS daemon.
2011-04-29 12:36:13 -07:00
Brian Behlendorf
1efb473f89 Add Hooks for Linux File Operations
The Linux specific file operations have all been located in the
file zpl_file.c.  These functions primarily rely on the reworked
zfs_* functions to do their job.  They are also responsible for
converting the possible Solaris style error codes to negative
Linux errors.

This first zpl_* commit also includes a common zpl.h header with
minimal entries to register the Linux specific hooks.  In also
adds all the new zpl_* file to the Makefile.in.  This is not a
standalone commit, you required the following zpl_* commits.
2011-02-10 09:27:21 -08:00
Brian Behlendorf
bcf308227c Remove zfs_ctldir.[ch]
This code is used for snapshot and heavily leverages Solaris
functionality we do not want to reimplement.  These files have
been removed, including references to them, and will be replaced
by a zfs_snap.c/zpl_snap.c implementation which handles snapshots.
2011-02-10 09:27:21 -08:00
Brian Behlendorf
6283f55ea1 Support custom build directories and move includes
One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory.  The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.

For example, this project is designed to work on various different
Linux distributions each of which work slightly differently.  This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.

Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution.  When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.

wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z

------------------------- run concurrently ----------------------
<ubuntu system>  <fedora system>  <debian system>  <rhel6 system>
mkdir ubuntu     mkdir fedora     mkdir debian     mkdir rhel6
cd ubuntu        cd fedora        cd debian        cd rhel6
../configure     ../configure     ../configure     ../configure
make             make             make             make
make check       make check       make check       make check

This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory.  This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.
2010-09-08 12:38:56 -07:00
Brian Behlendorf
60101509ee Add linux kernel disk support
Native Linux vdev disk interfaces

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-08-31 13:41:57 -07:00
Brian Behlendorf
c9c0d073da Add build system
Add autoconf style build infrastructure to the ZFS tree.  This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.
2010-08-31 13:41:27 -07:00