Commit Graph

64 Commits

Author SHA1 Message Date
Brian Behlendorf 65037d9b25 Add libzfs_error_init() function
All fprintf() error messages are moved out of the libzfs_init()
library function where they never belonged in the first place.  A
libzfs_error_init() function is added to provide useful error
messages for the most common causes of failure.

Additionally, in libzfs_run_process() the 'rc' variable was renamed
to 'error' for consistency with the rest of the code base.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
2015-05-22 13:34:58 -07:00
Brian Behlendorf 1a5c611a22 Make command line guid parsing more tolerant
Several of the zfs utilities allow you to pass a vdev's guid rather
than the device name.  However, the utilities are not consistent in
how they parse that guid.  For example, 'zinject' expects the guid
to be passed as a hex value while 'zpool replace' wants it as a
decimal.  The user is forced to just know what format to use.

This patch improve things by making the parsing more tolerant.
When strtol(3) is called using 0 for the base, rather than say
10 or 16, it will then accept hex, decimal, or octal input based
on the prefix.  From the man page.

    If base is zero or 16, the string may then include a "0x"
    prefix, and  the number  will  be read in base 16; otherwise,
    a zero base is taken as 10 (decimal) unless the next character
    is '0', in which case it  is  taken as 8 (octal).

NOTE: There may be additional conversions not caught be this patch.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Issue #2
2014-04-02 13:10:08 -07:00
Yuri Pankov d3773fda14 Illumos #3120 zinject hangs in zfsdev_ioctl() due to uninitialized zc
3120 zinject hangs in zfsdev_ioctl() due to uninitialized zc

Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/3120
  illumos/illumos-gate@f4c46b1eda

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2152
2014-03-24 11:06:11 -07:00
Maximilian Mehnert 539defc873 Add missing libzfs_core to Makefiles
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
2013-11-20 15:44:15 -08:00
Richard Yao 31fc19399e Generate libraries with correct DT_NEEDED entries
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
2013-10-10 16:56:51 -07:00
Turbo Fredriksson f9e459d143 Use setmntent() OR fopen()
For the same reasons it's used in libzfs_init(), this was just
overlooked because zinject gets minimal use.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1498
2013-08-15 10:09:09 -07:00
Brian Behlendorf 937210a54b Fix zinject list handlers
The zfs_fd must be opened before calling print_all_handlers() or
the ioctl() cannot be used to the zfs control device.  This brings
the zinject code back in sync with the Illumos implementation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-05-01 17:05:58 -07:00
George.Wilson cc92e9d0c3 3246 ZFS I/O deadman thread
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

NOTES: This patch has been reworked from the original in the
following ways to accomidate Linux ZFS implementation

*) Usage of the cyclic interface was replaced by the delayed taskq
   interface.  This avoids the need to implement new compatibility
   code and allows us to rely on the existing taskq implementation.

*) An extern for zfs_txg_synctime_ms was added to sys/dsl_pool.h
   because declaring externs in source files as was done in the
   original patch is just plain wrong.

*) Instead of panicing the system when the deadman triggers a
   zevent describing the blocked vdev and the first pending I/O
   is posted.  If the panic behavior is desired Linux provides
   other generic methods to panic the system when threads are
   observed to hang.

*) For reference, to delay zios by 30 seconds for testing you can
   use zinject as follows: 'zinject -d <vdev> -D30 <pool>'

References:
  illumos/illumos-gate@283b84606b
  https://www.illumos.org/issues/3246

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1396
2013-05-01 17:05:52 -07:00
Brian Behlendorf ca8b5af89d Remove autotools products
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
2012-08-27 11:47:44 -07:00
Etienne Dechamps ee5fd0bb80 Set zvol discard_granularity to the volblocksize.
Currently, zvols have a discard granularity set to 0, which suggests to
the upper layer that discard requests of arbirarily small size and
alignment can be made efficiently.

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

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

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #862
2012-08-07 14:55:31 -07:00
Richard Yao 739a1a82e0 Linux 3.5 compat, end_writeback() changed to clear_inode()
The end_writeback() function was changed by moving the call to
inode_sync_wait() earlier in to evict().   This effecitvely changes
the ordering of the sync but it does not impact the details of
the zfs implementation.

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

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

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

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

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #784
2012-07-23 12:29:23 -07:00
Etienne Dechamps b5a28807cd Move partition scanning from userspace to module.
Currently, zpool online -e (dynamic vdev expansion) doesn't work on
whole disks because we're invoking ioctl(BLKRRPART) from userspace
while ZFS still has a partition open on the disk, which results in
EBUSY.

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

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

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

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #808
2012-07-17 09:17:31 -07:00
Richard Yao 6a0936babc Linux 3.4 compat, d_make_root() replaces d_alloc_root()
torvalds/linux@adc0e91ab1 introduced
introduced d_make_root() as a replacement for d_alloc_root(). Further
commits appear to have removed d_alloc_root() from the Linux source
tree. This causes the following failure:

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

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

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #776
2012-06-11 10:04:49 -07:00
Brian Behlendorf b39d3b9f7b Linux 3.3 compat, iops->create()/mkdir()/mknod()
The mode argument of iops->create()/mkdir()/mknod() was changed from
an 'int' to a 'umode_t'.  To prevent a compiler warning an autoconf
check was added to detect the API change and then correctly set a
zpl_umode_t typedef.  There is no functional change.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #701
2012-04-30 12:52:38 -07:00
Brian Behlendorf 1c5de20ae2 Add --enable-debug-dmu-tx configure option
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>
2012-03-23 12:25:17 -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
Brian Behlendorf 4b787d75c8 Cleanly support debug packages
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>
2012-02-27 14:08:17 -08:00
Etienne Dechamps 30930fba21 Add support for DISCARD to ZVOLs.
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>
2012-02-09 16:19:38 -08:00
Etienne Dechamps cb2d19010d Support the fallocate() file operation.
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
2012-02-09 16:19:32 -08:00
Etienne Dechamps 34037afe24 Improve ZVOL queue behavior.
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>
2012-02-07 16:23:06 -08:00
Etienne Dechamps b18019d2d8 Fix synchronicity for ZVOLs.
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>
2012-02-07 16:23:06 -08:00
Brian Behlendorf 47621f3d76 Linux 3.3 compat, sops->show_options()
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
2012-02-03 10:02:01 -08:00
Darik Horn 750562833f Combine libraries: spl, avl, efi, share, unicode.
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
2012-01-17 15:19:50 -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
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 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
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 de0a1c099b Autogen refresh for udev changes
Run autogen.sh using the same autotools versions as upstream:

 * autoconf-2.63
 * automake-1.11.1
 * libtool-2.2.6b
2011-08-08 16:30:27 -07:00
Brian Behlendorf 76659dc110 Add backing_device_info per-filesystem
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
2011-08-04 13:37:38 -07:00
Kyle Fuller 615ab66d18 Provide a rc.d script for archlinux
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
2011-07-11 14:12:23 -07:00
Brian Behlendorf 2cf7f52bc4 Linux compat 2.6.39: mount_nodev()
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 #246
Closes #217
Closes #187
Closes #248
Closes #231
2011-07-01 13:36:39 -07:00
Brian Behlendorf 5c03efc379 Linux compat 2.6.39: security_inode_init_security()
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 #246
Closes #217
Closes #187
2011-07-01 12:40:08 -07:00
Prasad Joshi b312979252 Tear down and flush the mmap region
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
2011-06-27 09:59:19 -07:00
Brian Behlendorf 2e08aedba4 Always check -Wno-unused-but-set-variable gcc support
The previous commit 8a7e1ceefa wasn't
quite right.  This check applies to both the user and kernel space
build and as such we must make sure it runs regardless of what
the --with-config option is set too.

For example, if --with-config=kernel then the autoconf test does
not run and we generate build warnings when compiling the kernel
packages.
2011-06-14 16:40:35 -07:00
Brian Behlendorf 8a7e1ceefa Check for -Wno-unused-but-set-variable gcc support
Gcc versions 4.3.2 and earlier do not support the compiler flag
-Wno-unused-but-set-variable.  This can lead to build failures
on older Linux platforms such as Debian Lenny.  Since this is
an optional build argument this changes add a new autoconf check
for the option.  If it is supported by the installed version of
gcc then it is used otherwise it is omited.

See commit's 12c1acde76 and
79713039a2 for the reason the
-Wno-unused-but-set-variable options was originally added.
2011-06-14 14:43:22 -07:00
Brian Behlendorf df554c148e Fix 'zfs set volsize=N pool/dataset'
This change fixes a kernel panic which would occur when resizing
a dataset which was not open.  The objset_t stored in the
zvol_state_t will be set to NULL when the block device is closed.
To avoid this issue we pass the correct objset_t as the third arg.

The code has also been updated to correctly notify the kernel
when the block device capacity changes.  For 2.6.28 and newer
kernels the capacity change will be immediately detected.  For
earlier kernels the capacity change will be detected when the
device is next opened.  This is a known limitation of older
kernels.

Online ext3 resize test case passes on 2.6.28+ kernels:
$ dd if=/dev/zero of=/tmp/zvol bs=1M count=1 seek=1023
$ zpool create tank /tmp/zvol
$ zfs create -V 500M tank/zd0
$ mkfs.ext3 /dev/zd0
$ mkdir /mnt/zd0
$ mount /dev/zd0 /mnt/zd0
$ df -h /mnt/zd0
$ zfs set volsize=800M tank/zd0
$ resize2fs /dev/zd0
$ df -h /mnt/zd0

Original-patch-by: Fajar A. Nugraha <github@fajar.net>
Closes #68
Closes #84
2011-05-02 08:54:40 -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 12c1acde76 Set -Wno-unused-but-set-variable globally
As of gcc-4.6 the option -Wunused-but-set-variable is enabled by
default.  While this is a useful warning there are numerous places
in the ZFS code when a variable is set and then only checked in an
ASSERT().  To avoid having to update every instance of this in the
code we now set -Wno-unused-but-set-variable to suppress the warning.

Additionally, when building with --enable-debug and -Werror set these
warning also become fatal.  We can reevaluate the suppression of these
error at a later time if it becomes an issue.  For now we are basically
just reverting to the previous gcc behavior.
2011-04-19 10:44:10 -07:00
Brian Behlendorf bdf4328b04 Linux 2.6.28 compat, insert_inode_locked()
Added insert_inode_locked() helper function, prior to this most callers
used insert_inode_hash().  The older method doesn't check for collisions
in the inode_hashtable but it still acceptible for use.  Fallback to
using insert_inode_hash() when insert_inode_locked() is unavailable.
2011-03-22 12:15:54 -07:00
Brian Behlendorf 01c0e61da0 Add init scripts
To support automatically mounting your zfs on filesystem on boot
a basic init script is needed.  Unfortunately, every distribution
has their own idea of the _right_ way to do things.  Rather than
write one very complicated portable init script, which would be
invariably replaced by the distributions own anyway.  I have
instead added support to provide multiple distribution specific
init scripts.

The correct init script for your distribution will be selected
by ZFS_AC_DEFAULT_PACKAGE which will set DEFAULT_INIT_SCRIPT.
During 'make install' the correct script for your system will
be installed from zfs/etc/init.d/zfs.DEFAULT_INIT_SCRIPT to the
usual /etc/init.d/zfs location.

Currently, there is zfs.fedora and a more generic zfs.lsb init
script.  Hopefully, the distribution maintainers who know best
how they want their init scripts to function will feedback their
approved versions to be included in the project.

This change does not consider upstart jobs but I'm not at all
opposed to add that sort of thing.
2011-03-17 16:51:54 -07:00
Brian Behlendorf 45066d1f20 Linux 2.6.38 compat, blkdev_get_by_path()
The open_bdev_exclusive() function has been replaced (again) by the
more generic blkdev_get_by_path() function.  Additionally, the
counterpart function close_bdev_exclusive() has been replaced by
blkdev_put().  Because these functions are more generic versions
of the functions they replaced the compatibility macro must add
the FMODE_EXCL mask to ensure they are exclusive.

Closes #114
2011-02-23 12:29:38 -08:00
Brian Behlendorf 2c395def27 Linux 2.6.36 compat, sops->evict_inode()
The new prefered inteface for evicting an inode from the inode cache
is the ->evict_inode() callback.  It replaces both the ->delete_inode()
and ->clear_inode() callbacks which were previously used for this.
2011-02-11 13:47:51 -08:00
Brian Behlendorf 7268e1bec8 Linux 2.6.35 compat, fops->fsync()
The fsync() callback in the file_operations structure used to take
3 arguments.  The callback now only takes 2 arguments because the
dentry argument was determined to be unused by all consumers.  To
handle this a compatibility prototype was added to ensure the right
prototype is used.  Our implementation never used the dentry argument
either so it's just a matter of using the right prototype.
2011-02-11 09:05:51 -08:00
Brian Behlendorf 777d4af891 Linux 2.6.35 compat, const struct xattr_handler
The const keyword was added to the 'struct xattr_handler' in the
generic Linux super_block structure.  To handle this we define an
appropriate xattr_handler_t typedef which can be used.  This was
the preferred solution because it keeps the code clean and readable.
2011-02-10 16:29:00 -08:00
Brian Behlendorf 1ac0ea38a5 Add missing -ldl linker option
The inclusion on dlsym(), dlopen(), and dlclose() symbols require
us to link against the dl library.  Be careful to add the flag to
both the libzfs library and the commands which depend on the library.
2011-02-10 11:05:44 -08:00
Brian Behlendorf b4ead57cfb Remove HAVE_ZPL from commands and libraries
Thanks to the previous few commits we can now build all of the
user space commands and libraries with support for the zpl.
2011-02-04 16:14:34 -08:00
Brian Behlendorf 9a616b5d17 Documentation updates
Minor Linux specific documentation updates to the comments and
man pages.
2011-02-04 16:14:34 -08:00
Brian Behlendorf c5d915f423 Minimal libshare infrastructure
ZFS even under Solaris does not strictly require libshare to be
available.  The current implementation attempts to dlopen() the
library to access the needed symbols.  If this fails libshare
support is simply disabled.

This means that on Linux we only need the most minimal libshare
implementation.  In fact just enough to prevent the build from
failing.  Longer term we can decide if we want to implement a
libshare library like Solaris.  At best this would be an abstraction
layer between ZFS and NFS/SMB.  Alternately, we can drop libshare
entirely and directly integrate ZFS with Linux's NFS/SMB.

Finally the bare bones user-libshare.m4 test was dropped.  If we
do decide to implement libshare at some point it will surely be
as part of this package so the check is not needed.
2011-02-04 16:14:29 -08:00