The issue with hot spares in ZoL is because it opens all leaf
vdevs exclusively (O_EXCL). On Linux, exclusive opens cause
subsequent exclusive opens to fail with EBUSY.
This could be resolved by not opening any of the devices
exclusively, which is what Illumos does, but the additional
protection offered by exclusive opens is desirable. It cleanly
prevents you from accidentally adding an in-use non-ZFS device
to your pool.
To fix this we very slightly relaxed the usage of O_EXCL in
the following ways.
1) Functions which open the device but only read had the
O_EXCL flag removed and were updated to use O_RDONLY.
2) A common holder was added to the vdev disk code. This
allow the ZFS code to internally open the device multiple
times but non-ZFS callers may not.
3) An exception was added to make_disks() for hot spare when
creating partition tables. For hot spare devices which
are already opened exclusively we skip creating the partition
table because this must already have been done when the disk
was originally added as a hot spare.
Additional minor changes include fixing check_in_use() to use
a partition instead of a slice suffix. And is_spare() was moved
above make_disks() to avoid adding a forward reference.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#250
`zpool status -x` should only flag errors or where the pool is
unavailable. If it imported fine but isn't using the latest features
available in the code, that's not an error.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#1319
This is a minor nit, but the second line of the 'action' message
when you need to upgrade your pool to support feature flags exceeds
the standard 80 character limit. Fix it by moving the word
'feature' on to the third line.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
1337 `zpool status -D' should tell if there are no DDT entries
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Approved by: Albert Lee <trisk@nexenta.com>
References:
illumos/illumos-gate@ce72e614c1
illumos changeset: 13432:d1ad8d106d64
https://www.illumos.org/issues/1337
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
2762 zpool command should have better support for feature flags
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>
References:
illumos/illumos-gate@57221772c3https://www.illumos.org/issues/2762
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
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>
Commit df83110856 missed update to
getopt() call, while delivering all the rest. This commit adds
"o" to getopt().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #566
When adding devices to an existing pool "ashift" property is
auto-detected. However, if this property was overridden at
the pool creation time (i.e. zpool create -o ashift=12 tank ...)
this may not be what the user wants. This commit lets the user
specify the value of "ashift" property to be used with newly
added drives. For example,
zpool add -o ashift=12 tank disk1
zpool attach -o ashift=12 tank disk1 disk2
Signed-off-by: Cyril Plisko <cyril.plisko@mountall.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#566
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Richard Lowe <richlowe@richlowe.net>
Refererces to Illumos issue:
https://www.illumos.org/issues/2671
This patch has been slightly modified from the upstream Illumos
version. In the upstream implementation a warning message is
logged to the console. To prevent pointless console noise this
notification is now posted as a "ereport.fs.zfs.vdev.bad_ashift"
event.
The event indicates a non-optimial (but entirely safe) ashift
value was used to create the pool. Depending on your workload
this may impact pool performance. Unfortunately, the only way
to correct the issue is to recreate the pool with a new ashift.
NOTE: The unrelated fix to the comment in zpool_main.c appears
in the upstream commit and was preserved for consistnecy.
Ported-by: Cyril Plisko <cyril.plisko@mountall.com>
Reworked-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#955
The 'zpool replace' command would fail when given a short name
because unlike on other platforms the short name cannot be
deterministically expanded to a single path. Multiple path
prefixes must be checked and in addition the partition suffix
for whole disks is determined by the prefix.
To handle this complexity a zfs_strcmp_pathname() function was
added which takes either a short or fully qualified device name.
Short names will be expanded using the prefixes in the default
import search path, or the ZPOOL_IMPORT_PATH environment variable
if it's defined. All posible expansions are then compared against
the comparison path. Care is taken to strip redundant slashes to
ensure legitimate matches are not missed.
In the context of this work the existing zfs_resolve_shortname()
function was extended to consider the ZPOOL_IMPORT_PATH when set.
The zfs_append_partition() interface was also simplified to take
only a single buffer.
The vast majority of these changes rework existing Linux specific
code which was originally written to accomidate udev. However,
there is some minimal cleanup which removes Illumos specific code.
This was done to improve readability but the basic flow and intent
of the upstream code was maintained.
These changes are the logical conclusion of the previos work to
adjust the 'zpool import' search behavior, see commit 44867b6a.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#544Closes#976
The goal of this change is to make 'zpool import' prefer to use
the peristent /dev/mapper or /dev/disk/by-* paths. These are far
preferable to the devices in /dev/ whos names are not persistent
and are determined by the order in which a device is detected.
This patch improves things by changing the default search path from
just to the top level /dev/ directory to (in order):
/dev/disk/by-vdev - Custom rules, use first if they exist
/dev/disk/zpool - Custom rules, use first if they exist
/dev/mapper - Use multipath devices before components
/dev/disk/by-uuid - Single unique entry and persistent
/dev/disk/by-id - May be multiple entries and persistent
/dev/disk/by-path - Encodes physical location and persistent
/dev/disk/by-label - Custom persistent labels
/dev - UNSAFE device names will change
The default search path can be overriden by setting the
ZPOOL_IMPORT_PATH environment variable. This must be a colon
delimited list of paths which are searched for vdevs. If the
'zpool import -d' option is specified only those listed paths
will be searched.
Finally, when multiple paths to the same device are found. If one
of the paths is an exact match for the path used last time to import
the pool it will be used. When there are no exact matches the
prefered path will be determined by the provided search order.
This means you can still import a pool and force specific names by
providing the -d <path> option. And the prefered names will persist
as long as those paths exist on your system.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#965
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
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/1693
Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#678
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
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: Alexander Eremin <alexander.eremin@nexenta.com>
Reviewed by: Alexander Stetsenko <ams@nexenta.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/1748
This commit modifies the user to kernel space ioctl ABI. Extra
care should be taken when updating to ensure both the kernel
modules and utilities are updated. If only the user space
component is updated both the 'zpool events' command and the
'zpool reguid' command will not work until the kernel modules
are updated.
Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#665
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
vdev_id parses the file /etc/zfs/vdev_id.conf to map a physical path
in a storage topology to a channel name. The channel name is combined
with a disk enclosure slot number to create an alias that reflects the
physical location of the drive. This is particularly helpful when it
comes to tasks like replacing failed drives. Slot numbers may also be
re-mapped in case the default numbering is unsatisfactory. The drive
aliases will be created as symbolic links in /dev/disk/by-vdev.
The only currently supported topologies are sas_direct and sas_switch:
o sas_direct - a channel is uniquely identified by a PCI slot and a
HBA port
o sas_switch - a channel is uniquely identified by a SAS switch port
A multipath mode is supported in which dm-mpath devices are handled by
examining the first running component disk, as reported by 'multipath
-l'. In multipath mode the configuration file should contain a
channel definition with the same name for each path to a given
enclosure.
vdev_id can replace the existing zpool_id script on systems where the
storage topology conforms to sas_direct or sas_switch. The script
could be extended to support other topologies as well. The advantage
of vdev_id is that it is driven by a single static input file that can
be shared across multiple nodes having a common storage toplogy.
zpool_id, on the other hand, requires a unique /etc/zfs/zdev.conf per
node and a separate slot-mapping file. However, zpool_id provides the
flexibility of using any device names that show up in
/dev/disk/by-path, so it may still be needed on some systems.
vdev_id's functionality subsumes that of the sas_switch_id script, and
it is unlikely that anyone is using it, so sas_switch_id is removed.
Finally, /dev/disk/by-vdev is added to the list of directories that
'zpool import' will scan.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#713
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
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Joshua M. Clulow <josh@sysmgr.org>
Approved by: Richard Lowe <richlowe@richlowe.net>
Reference to Illumos issue:
https://www.illumos.org/issues/1946
Ported by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>
Refererce to Illumos issue:
https://www.illumos.org/issues/952
Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#607
When stdout is detected to be a tty use the number of columns
specified by the terminal. If that fails fall back to a default
80 column width. In the non-tty case allow for 999 column lines.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Caught by lint, this permission change was accidentally introduced
by commit 42cb3819f1. Restore the
correct permissions and while I'm at it add a missing whack-bang
to config/ltmain.sh.
lint: executable-not-elf-or-script: zpool_main.c zfs_main.c
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#620
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
The 'zfs list' and 'zpool list' commands output the message
'no datasets/pools available' to stdout. This should go to
stderr and only the available datasets/pools should go to
stdout. Returning nothing to stdout is expected behavior
when there is nothing to list.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#581
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>
When creating a new pool, make_root_vdev() calls check_in_use() to
ensure that none of the consituent disks are in use. If the disk
contains a valid vdev label it is read to retrieve the list of its
child vdevs and these are checked recursively. However, the
partitions stored in the vdev label my no longer exist, for example
if the partition table has since been altered. In any such case we
would want the pool creation to proceed, so this change removes the
check from check_slice() that returns an error if the device doesn't
exist. As an added assurance, the Solaris implementation also
returns sucess on ENOENT.
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
ZFS contains error messages that point to the defunct www.sun.com
domain, which is currently offline. Change these error messages
to use the zfsonlinux.org mirror instead.
This commit depends on:
zfsonlinux/zfsonlinux.github.com@8e10ead3dc
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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 zpool sub-commands like iostat, list, and status should
display consistent message when a given pool is unavailable or
no pool is present. This change unifies the default behavior
as follows:
root@prasad:~# ./zpool list 1 2
no pools available
no pools available
root@prasad:~# ./zpool iostat 1 2
no pools available
no pools available
root@prasad:~# ./zpool status 1 2
no pools available
no pools available
root@prasad:~# ./zpool list tan 1 2
cannot open 'tan': no such pool
root@prasad:~# ./zpool iostat tan 1 2
cannot open 'tan': no such pool
root@prasad:~# ./zpool status tan 1 2
cannot open 'tan': no such pool
Reported-by: Rajshree Thorat <rthorat@stec-inc.com>
Signed-off-by: Prasad Joshi <pjoshi@stec-inc.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#306
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
Brian Behlendorf
Tim Connors
Yuri Pankov
Christopher Siden
Cyril Plisko
George Wilson
Dan McDonald
Etienne Dechamps
Richard Yao
Garrett D'Amore
Richard Yao
Ned A. Bass
Frederik Wessels
Mike Harsch
Craig Sanders
Gregor Kopka
Ned Bass
Darik Horn
Prakash Surya
Kyle Fuller
Prasad Joshi