4370 avoid transmitting holes during zfs send
4371 DMU code clean up
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Garrett D'Amore <garrett@damore.org>a
References:
https://www.illumos.org/issues/4370https://www.illumos.org/issues/4371https://github.com/illumos/illumos-gate/commit/43466aa
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2529
4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Approved by: Garrett D'Amore <garrett@damore.org>a
References:
https://www.illumos.org/issues/4171https://www.illumos.org/issues/4172https://github.com/illumos/illumos-gate/commit/2acef22
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2528
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/4101https://www.illumos.org/issues/4102https://www.illumos.org/issues/4103https://www.illumos.org/issues/4105https://www.illumos.org/issues/4106https://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
When given a pool name via -e, zdb would attempt an import. If it
failed, then it would attempt a verbatim import. This behavior is
not always desirable so a -V switch is added to zdb to control the
behavior. When specified, a verbatim import is done. Otherwise,
the behavior is as it was previously, except no verbatim import
is done on failure.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2372
This patch is a zdb extension of the '-b' option, producing a histogram
of the physical compressed block sizes per DMU object type on disk. The
'-bbbb' option to zdb will uncover this new feature; here's an example
usage on a new pool and snippet of the output it generates:
# zpool create tank /dev/vd{b,c,d}
# dd bs=1k if=/dev/urandom of=/tank/1kfile count=1
# dd bs=3k if=/dev/urandom of=/tank/3kfile count=1
# dd bs=64k if=/dev/urandom of=/tank/64kfile count=1
# zdb -bbbb tank
...
3 68.0K 68.0K 68.0K 22.7K 1.00 34.26 ZFS plain file
psize (in 512-byte sectors): number of blocks
2: 1 *
3: 0
4: 0
5: 0
6: 1 *
7: 0
...
127: 0
128: 1 *
...
The blocks are also broken down by their indirection level. Expanding on
the above example:
# zfs set recordsize=1k tank
# dd bs=1k if=/dev/urandom of=/tank/2x1kfile count=2
# zdb -bbbb tank
...
1 16K 1K 2K 2K 16.00 1.02 L1 ZFS plain file
psize (in 512-byte sectors): number of blocks
2: 1 *
5 70.0K 70.0K 70.0K 14.0K 1.00 35.71 L0 ZFS plain file
psize (in 512-byte sectors): number of blocks
2: 3 ***
3: 0
4: 0
5: 0
6: 1 *
7: 0
...
127: 0
128: 1 *
6 86.0K 71.0K 72.0K 12.0K 1.21 36.73 ZFS plain file
psize (in 512-byte sectors): number of blocks
2: 4 ****
3: 0
4: 0
5: 0
6: 1 *
7: 0
...
127: 0
128: 1 *
...
There's now a single 1K L1 block which is the indirect block needed for
the '2x1kfile' file just created, as well as two more 1K L0 blocks from
the same file.
This can be used to get a distribution of the block sizes used within
the pool, on a per object type basis.
References:
https://illumos.org/issues/3641https://github.com/illumos/illumos-gate/commit/490d05b
Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Boris Protopopov <boris.protopopov@me.com>
Closes#2456
The vast majority of these changes are in Linux specific code.
They are the result of not having an automated style checker to
validate the code when it was originally written. Others were
caused when the common code was slightly adjusted for Linux.
This patch contains no functional changes. It only refreshes
the code to conform to style guide.
Everyone submitting patches for inclusion upstream should now
run 'make checkstyle' and resolve any warning prior to opening
a pull request. The automated builders have been updated to
fail a build if when 'make checkstyle' detects an issue.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1821
On some platforms symbols provided by libzfs_core and used by
libzfs were not available to the linker. To avoid this issue
libzfs_core has been added to the list of required libraries
when building utilities which depend on libzfs. This should
have been handled properly by libtool and it's still not
entirely clear why it wasn't on all platforms.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1841
3603 panic from bpobj_enqueue_subobj()
3604 zdb should print bpobjs more verbosely
3871 GCC 4.5.3 does not like issue 3604 patch
Reviewed by: Henrik Mattson <henrik.mattson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
https://www.illumos.org/issues/3603https://www.illumos.org/issues/3604https://www.illumos.org/issues/3871illumos/illumos-gate@d04756377d
Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
Note that the patch from Illumos issue 3871 is not accepted into Illumos
at the time of this writing. It is something that I wrote when porting
this. Documentation is in the Illumos issue.
Libraries that depend on other libraries should list them in ELF's
DT_NEEDED field so that programs linking to them do not need to specify
those libraries unless they depend on them as well. This is not the case
in the current code and the consequence is that anything that needs a
library must know its dependencies. This is fragile and caused GRUB2's
configure script to break when a dependency was added on libblkid in
libzfs.
This resolves that problem by using LIBADD/LDADD to specify libraries in
Makefile.am instead of LDFLAGS. This ensures that proper DT_NEEDED
entries are generated and prevents GRUB2's configure script from
breaking in the presence of a libblkid dependency. This also removes
unneeded dependencies from various files.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1751
2882 implement libzfs_core
2883 changing "canmount" property to "on" should not always remount dataset
2900 "zfs snapshot" should be able to create multiple, arbitrary snapshots at once
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Chris Siden <christopher.siden@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>
References:
https://www.illumos.org/issues/2882https://www.illumos.org/issues/2883https://www.illumos.org/issues/2900illumos/illumos-gate@4445fffbbb
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1293
Porting notes:
WARNING: This patch changes the user/kernel ABI. That means that
the zfs/zpool utilities built from master are NOT compatible with
the 0.6.2 kernel modules. Ensure you load the matching kernel
modules from master after updating the utilities. Otherwise the
zfs/zpool commands will be unable to interact with your pool and
you will see errors similar to the following:
$ zpool list
failed to read pool configuration: bad address
no pools available
$ zfs list
no datasets available
Add zvol minor device creation to the new zfs_snapshot_nvl function.
Remove the logging of the "release" operation in
dsl_dataset_user_release_sync(). The logging caused a null dereference
because ds->ds_dir is zeroed in dsl_dataset_destroy_sync() and the
logging functions try to get the ds name via the dsl_dataset_name()
function. I've got no idea why this particular code would have worked
in Illumos. This code has subsequently been completely reworked in
Illumos commit 3b2aab1 (3464 zfs synctask code needs restructuring).
Squash some "may be used uninitialized" warning/erorrs.
Fix some printf format warnings for %lld and %llu.
Apply a few spa_writeable() changes that were made to Illumos in
illumos/illumos-gate.git@cd1c8b8 as part of the 3112, 3113, 3114 and
3115 fixes.
Add a missing call to fnvlist_free(nvl) in log_internal() that was added
in Illumos to fix issue 3085 but couldn't be ported to ZoL at the time
(zfsonlinux/zfs@9e11c73) because it depended on future work.
If the znode has SA xattrs, display them following the other
standard attributes. The format used is similar to that used
when listing the contents of a ZAP. It is as follows:
$ zdb -vvv <pool>/<dataset> <object>
...
SA xattrs: <size> bytes, <number> entries
<name1> = <value1>
<name2> = <value2>
...
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1581
Make sure that buffer is aligned to 512 bytes on linux so that
pread call combined with O_DIRECT does not return EINVAL.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1570
When using zdb with non-default SPA config file it is not convenient
to add -U <non-default-config-file-path> all the time. This commit
introduces support for setting/overriding SPA config location via
environment variable 'SPA_CONFIG_PATH'.
If -U flag is specified in the command line it will override any other
value as usual.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1545
3552 condensing one space map burns 3 seconds of CPU in spa_sync() thread
3564 spa_sync() spends 5-10% of its time in metaslab_sync() (when not condensing)
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
illumos/illumos-gate@16a4a80742https://www.illumos.org/issues/3552https://www.illumos.org/issues/3564
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1513
3306 zdb should be able to issue reads in parallel
3321 'zpool reopen' command should be documented in the man
page and help
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
References:
illumos/illumos-gate@31d7e8fa33https://www.illumos.org/issues/3306https://www.illumos.org/issues/3321
The vdev_file.c implementation in this patch diverges significantly
from the upstream version. For consistenty with the vdev_disk.c
code the upstream version leverages the Illumos bio interfaces.
This makes sense for Illumos but not for ZoL for two reasons.
1) The vdev_disk.c code in ZoL has been rewritten to use the
Linux block device interfaces which differ significantly
from those in Illumos. Therefore, updating the vdev_file.c
to use the Illumos interfaces doesn't get you consistency
with vdev_disk.c.
2) Using the upstream patch as is would requiring implementing
compatibility code for those Solaris block device interfaces
in user and kernel space. That additional complexity could
lead to confusion and doesn't buy us anything.
For these reasons I've opted to simply move the existing vn_rdwr()
as is in to the taskq function. This has the advantage of being
low risk and easy to understand. Moving the vn_rdwr() function
in to its own taskq thread also neatly avoids the possibility of
a stack overflow.
Finally, because of the additional work which is being handled by
the free taskq the number of threads has been increased. The
thread count under Illumos defaults to 100 but was decreased to 2
in commit 08d08e due to contention. We increase it to 8 until
the contention can be address by porting Illumos #3581.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1354
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@53089ab7c8illumos/illumos-gate@ad135b5d64
illumos changeset: 13700:2889e2596bd6
https://www.illumos.org/issues/2619https://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>
The interface for the ddt_zap_count() function assumes it can
never fail. However, internally ddt_zap_count() is implemented
with zap_count() which can potentially fail. Now because there
was no way to return the error to the caller a VERIFY was used
to ensure this case never happens.
Unfortunately, it has been observed that pools can be damaged in
such a way that zap_count() fails. The result is that the pool can
not be imported without hitting the VERIFY and crashing the system.
This patch reworks ddt_object_count() so the error can be safely
caught and returned to the caller. This allows a pool which has
be damaged in this way to be safely rewound for import.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#910
Without this fix the zdb printouts of ZIL data blocks look full of FF
due to printf() handling its arguments as int by default.
Here is the output before the fix
TX_WRITE len 4136, txg 1093817, seq 149231
foid 4242, offset 0, length f68
G FFFFFF8EFFFFFF87FFFFFF91FFFFFFCC 1c
FFFFFFAFFFFFFFC9FFFFFFBAZ FFFFFFC3
And the same after the fix
TX_WRITE len 4136, txg 1093817, seq 149231
foid 4242, offset 0, length f68
G 8E8791CC 1cAFC9BAZ C3
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#962
Remove all of the generated autotools products from the repository
and update the .gitignore files accordingly.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#718
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
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
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
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
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
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
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
Allow rigorous (and expensive) tx validation to be enabled/disabled
indepentantly from the standard zfs debugging. When enabled these
checks ensure that all txs are constructed properly and that a dbuf
is never dirtied without taking the correct tx hold.
This checking is particularly helpful when adding new dmu consumers
like Lustre. However, for established consumers such as the zpl
with no known outstanding tx construction problems this is just
overhead.
--enable-debug-dmu-tx - Enable/disable validation of each tx as
--disable-debug-dmu-tx it is constructed. By default validation
is disabled due to performance concerns.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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
Allow a source rpm to be rebuilt with debugging enabled. This
avoids the need to have to manually modify the spec file. By
default debugging is still largely disabled. To enable specific
debugging features use the following options with rpmbuild.
'--with debug' - Enables ASSERTs
# For example:
$ rpmbuild --rebuild --with debug zfs-modules-0.6.0-rc6.src.rpm
Additionally, ZFS_CONFIG has been added to zfs_config.h for
packages which build against these headers. This is critical
to ensure both zfs and the dependant package are using the same
prototype and structure definitions.
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
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>
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
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 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
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
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
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
For a long time now the kernel has been moving away from using the
pdflush daemon to write 'old' dirty pages to disk. The primary reason
for this is because the pdflush daemon is single threaded and can be
a limiting factor for performance. Since pdflush sequentially walks
the dirty inode list for each super block any delay in processing can
slow down dirty page writeback for all filesystems.
The replacement for pdflush is called bdi (backing device info). The
bdi system involves creating a per-filesystem control structure each
with its own private sets of queues to manage writeback. The advantage
is greater parallelism which improves performance and prevents a single
filesystem from slowing writeback to the others.
For a long time both systems co-existed in the kernel so it wasn't
strictly required to implement the bdi scheme. However, as of
Linux 2.6.36 kernels the pdflush functionality has been retired.
Since ZFS already bypasses the page cache for most I/O this is only
an issue for mmap(2) writes which must go through the page cache.
Even then adding this missing support for newer kernels was overlooked
because there are other mechanisms which can trigger writeback.
However, there is one critical case where not implementing the bdi
functionality can cause problems. If an application handles a page
fault it can enter the balance_dirty_pages() callpath. This will
result in the application hanging until the number of dirty pages in
the system drops below the dirty ratio.
Without a registered backing_device_info for the filesystem the
dirty pages will not get written out. Thus the application will hang.
As mentioned above this was less of an issue with older kernels because
pdflush would eventually write out the dirty pages.
This change adds a backing_device_info structure to the zfs_sb_t
which is already allocated per-super block. It is then registered
when the filesystem mounted and unregistered on unmount. It will
not be registered for mounted snapshots which are read-only. This
change will result in flush-<pool> thread being dynamically created
and destroyed per-mounted filesystem for writeback.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#174
Unlike most other Linux distributions archlinux installs its
init scripts in /etc/rc.d insead of /etc/init.d. This commit
provides an archlinux rc.d script for zfs and extends the
build infrastructure to ensure it get's installed in the
correct place.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#322
The .get_sb callback has been replaced by a .mount callback
in the file_system_type structure. When using the new
interface the caller must now use the mount_nodev() helper.
Unfortunately, the new interface no longer passes the vfsmount
down to the zfs layers. This poses a problem for the existing
implementation because we currently save this pointer in the
super block for latter use. It provides our only entry point
in to the namespace layer for manipulating certain mount options.
This needed to be done originally to allow commands like
'zfs set atime=off tank' to work properly. It also allowed me
to keep more of the original Solaris code unmodified. Under
Solaris there is a 1-to-1 mapping between a mount point and a
file system so this is a fairly natural thing to do. However,
under Linux they many be multiple entries in the namespace
which reference the same filesystem. Thus keeping a back
reference from the filesystem to the namespace is complicated.
Rather than introduce some ugly hack to get the vfsmount and
continue as before. I'm leveraging this API change to update
the ZFS code to do things in a more natural way for Linux.
This has the upside that is resolves the compatibility issue
for the long term and fixes several other minor bugs which
have been reported.
This commit updates the code to remove this vfsmount back
reference entirely. All modifications to filesystem mount
options are now passed in to the kernel via a '-o remount'.
This is the expected Linux mechanism and allows the namespace
to properly handle any options which apply to it before passing
them on to the file system itself.
Aside from fixing the compatibility issue, removing the
vfsmount has had the benefit of simplifying the code. This
change which fairly involved has turned out nicely.
Closes#246Closes#217Closes#187Closes#248Closes#231
The security_inode_init_security() function now takes an additional
qstr argument which must be passed in from the dentry if available.
Passing a NULL is safe when no qstr is available the relevant
security checks will just be skipped.
Closes#246Closes#217Closes#187
The inode eviction should unmap the pages associated with the inode.
These pages should also be flushed to disk to avoid the data loss.
Therefore, use truncate_setsize() in evict_inode() to release the
pagecache.
The API truncate_setsize() was added in 2.6.35 kernel. To ensure
compatibility with the old kernel, the patch defines its own
truncate_setsize function.
Signed-off-by: Prasad Joshi <pjoshi@stec-inc.com>
Closes#255
