mirror of
https://git.proxmox.com/git/mirror_zfs.git
synced 2024-11-17 18:11:00 +03:00
e5030fbc28
52 Commits
Author | SHA1 | Message | Date | |
---|---|---|---|---|
Ryan Moeller
|
957c7aa23c |
Relocate common quota functions to shared code
The quota functions are common to all implementations and can be moved to common code. As a simplification they were moved to the Linux platform code in the initial refactoring. Reviewed-by: Jorgen Lundman <lundman@lundman.net> Reviewed-by: Igor Kozhukhov <igor@dilos.org> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Ryan Moeller <ryan@ixsystems.com> Closes #9710 |
||
Paul Dagnelie
|
ca5777793e |
Reduce loaded range tree memory usage
This patch implements a new tree structure for ZFS, and uses it to store range trees more efficiently. The new structure is approximately a B-tree, though there are some small differences from the usual characterizations. The tree has core nodes and leaf nodes; each contain data elements, which the elements in the core nodes acting as separators between its children. The difference between core and leaf nodes is that the core nodes have an array of children, while leaf nodes don't. Every node in the tree may be only partially full; in most cases, they are all at least 50% full (in terms of element count) except for the root node, which can be less full. Underfull nodes will steal from their neighbors or merge to remain full enough, while overfull nodes will split in two. The data elements are contained in tree-controlled buffers; they are copied into these on insertion, and overwritten on deletion. This means that the elements are not independently allocated, which reduces overhead, but also means they can't be shared between trees (and also that pointers to them are only valid until a side-effectful tree operation occurs). The overhead varies based on how dense the tree is, but is usually on the order of about 50% of the element size; the per-node overheads are very small, and so don't make a significant difference. The trees can accept arbitrary records; they accept a size and a comparator to allow them to be used for a variety of purposes. The new trees replace the AVL trees used in the range trees today. Currently, the range_seg_t structure contains three 8 byte integers of payload and two 24 byte avl_tree_node_ts to handle its storage in both an offset-sorted tree and a size-sorted tree (total size: 64 bytes). In the new model, the range seg structures are usually two 4 byte integers, but a separate one needs to exist for the size-sorted and offset-sorted tree. Between the raw size, the 50% overhead, and the double storage, the new btrees are expected to use 8*1.5*2 = 24 bytes per record, or 33.3% as much memory as the AVL trees (this is for the purposes of storing metaslab range trees; for other purposes, like scrubs, they use ~50% as much memory). We reduced the size of the payload in the range segments by teaching range trees about starting offsets and shifts; since metaslabs have a fixed starting offset, and they all operate in terms of disk sectors, we can store the ranges using 4-byte integers as long as the size of the metaslab divided by the sector size is less than 2^32. For 512-byte sectors, this is a 2^41 (or 2TB) metaslab, which with the default settings corresponds to a 256PB disk. 4k sector disks can handle metaslabs up to 2^46 bytes, or 2^63 byte disks. Since we do not anticipate disks of this size in the near future, there should be almost no cases where metaslabs need 64-byte integers to store their ranges. We do still have the capability to store 64-byte integer ranges to account for cases where we are storing per-vdev (or per-dnode) trees, which could reasonably go above the limits discussed. We also do not store fill information in the compact version of the node, since it is only used for sorted scrub. We also optimized the metaslab loading process in various other ways to offset some inefficiencies in the btree model. While individual operations (find, insert, remove_from) are faster for the btree than they are for the avl tree, remove usually requires a find operation, while in the AVL tree model the element itself suffices. Some clever changes actually caused an overall speedup in metaslab loading; we use approximately 40% less cpu to load metaslabs in our tests on Illumos. Another memory and performance optimization was achieved by changing what is stored in the size-sorted trees. When a disk is heavily fragmented, the df algorithm used by default in ZFS will almost always find a number of small regions in its initial cursor-based search; it will usually only fall back to the size-sorted tree to find larger regions. If we increase the size of the cursor-based search slightly, and don't store segments that are smaller than a tunable size floor in the size-sorted tree, we can further cut memory usage down to below 20% of what the AVL trees store. This also results in further reductions in CPU time spent loading metaslabs. The 16KiB size floor was chosen because it results in substantial memory usage reduction while not usually resulting in situations where we can't find an appropriate chunk with the cursor and are forced to use an oversized chunk from the size-sorted tree. In addition, even if we do have to use an oversized chunk from the size-sorted tree, the chunk would be too small to use for ZIL allocations, so it isn't as big of a loss as it might otherwise be. And often, more small allocations will follow the initial one, and the cursor search will now find the remainder of the chunk we didn't use all of and use it for subsequent allocations. Practical testing has shown little or no change in fragmentation as a result of this change. If the size-sorted tree becomes empty while the offset sorted one still has entries, it will load all the entries from the offset sorted tree and disregard the size floor until it is unloaded again. This operation occurs rarely with the default setting, only on incredibly thoroughly fragmented pools. There are some other small changes to zdb to teach it to handle btrees, but nothing major. Reviewed-by: George Wilson <gwilson@delphix.com> Reviewed-by: Matt Ahrens <matt@delphix.com> Reviewed by: Sebastien Roy seb@delphix.com Reviewed-by: Igor Kozhukhov <igor@dilos.org> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes #9181 |
||
Matthew Macy
|
d66620681d |
OpenZFS restructuring - move linux tracing code to platform directories
Move Linux specific tracing headers and source to platform directories and update the build system. Reviewed-by: Allan Jude <allanjude@freebsd.org> Reviewed-by: Ryan Moeller <ryan@ixsystems.com> Reviewed by: Brad Lewis <brad.lewis@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Matt Macy <mmacy@FreeBSD.org> Closes #9290 |
||
Matthew Macy
|
bced7e3aaa |
OpenZFS restructuring - move platform specific sources
Move platform specific Linux source under module/os/linux/ and update the build system accordingly. Additional code restructuring will follow to make the common code fully portable. Reviewed-by: Jorgen Lundman <lundman@lundman.net> Reviewed-by: Igor Kozhukhov <igor@dilos.org> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Matthew Macy <mmacy@FreeBSD.org> Closes #9206 |
||
Serapheim Dimitropoulos
|
93e28d661e |
Log Spacemap Project
= Motivation At Delphix we've seen a lot of customer systems where fragmentation is over 75% and random writes take a performance hit because a lot of time is spend on I/Os that update on-disk space accounting metadata. Specifically, we seen cases where 20% to 40% of sync time is spend after sync pass 1 and ~30% of the I/Os on the system is spent updating spacemaps. The problem is that these pools have existed long enough that we've touched almost every metaslab at least once, and random writes scatter frees across all metaslabs every TXG, thus appending to their spacemaps and resulting in many I/Os. To give an example, assuming that every VDEV has 200 metaslabs and our writes fit within a single spacemap block (generally 4K) we have 200 I/Os. Then if we assume 2 levels of indirection, we need 400 additional I/Os and since we are talking about metadata for which we keep 2 extra copies for redundancy we need to triple that number, leading to a total of 1800 I/Os per VDEV every TXG. We could try and decrease the number of metaslabs so we have less I/Os per TXG but then each metaslab would cover a wider range on disk and thus would take more time to be loaded in memory from disk. In addition, after it's loaded, it's range tree would consume more memory. Another idea would be to just increase the spacemap block size which would allow us to fit more entries within an I/O block resulting in fewer I/Os per metaslab and a speedup in loading time. The problem is still that we don't deal with the number of I/Os going up as the number of metaslabs is increasing and the fact is that we generally write a lot to a few metaslabs and a little to the rest of them. Thus, just increasing the block size would actually waste bandwidth because we won't be utilizing our bigger block size. = About this patch This patch introduces the Log Spacemap project which provides the solution to the above problem while taking into account all the aforementioned tradeoffs. The details on how it achieves that can be found in the references sections below and in the code (see Big Theory Statement in spa_log_spacemap.c). Even though the change is fairly constraint within the metaslab and lower-level SPA codepaths, there is a side-change that is user-facing. The change is that VDEV IDs from VDEV holes will no longer be reused. To give some background and reasoning for this, when a log device is removed and its VDEV structure was replaced with a hole (or was compacted; if at the end of the vdev array), its vdev_id could be reused by devices added after that. Now with the pool-wide space maps recording the vdev ID, this behavior can cause problems (e.g. is this entry referring to a segment in the new vdev or the removed log?). Thus, to simplify things the ID reuse behavior is gone and now vdev IDs for top-level vdevs are truly unique within a pool. = Testing The illumos implementation of this feature has been used internally for a year and has been in production for ~6 months. For this patch specifically there don't seem to be any regressions introduced to ZTS and I have been running zloop for a week without any related problems. = Performance Analysis (Linux Specific) All performance results and analysis for illumos can be found in the links of the references. Redoing the same experiments in Linux gave similar results. Below are the specifics of the Linux run. After the pool reached stable state the percentage of the time spent in pass 1 per TXG was 64% on average for the stock bits while the log spacemap bits stayed at 95% during the experiment (graph: sdimitro.github.io/img/linux-lsm/PercOfSyncInPassOne.png). Sync times per TXG were 37.6 seconds on average for the stock bits and 22.7 seconds for the log spacemap bits (related graph: sdimitro.github.io/img/linux-lsm/SyncTimePerTXG.png). As a result the log spacemap bits were able to push more TXGs, which is also the reason why all graphs quantified per TXG have more entries for the log spacemap bits. Another interesting aspect in terms of txg syncs is that the stock bits had 22% of their TXGs reach sync pass 7, 55% reach sync pass 8, and 20% reach 9. The log space map bits reached sync pass 4 in 79% of their TXGs, sync pass 7 in 19%, and sync pass 8 at 1%. This emphasizes the fact that not only we spend less time on metadata but we also iterate less times to convergence in spa_sync() dirtying objects. [related graphs: stock- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGStock.png lsm- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGLSM.png] Finally, the improvement in IOPs that the userland gains from the change is approximately 40%. There is a consistent win in IOPS as you can see from the graphs below but the absolute amount of improvement that the log spacemap gives varies within each minute interval. sdimitro.github.io/img/linux-lsm/StockVsLog3Days.png sdimitro.github.io/img/linux-lsm/StockVsLog10Hours.png = Porting to Other Platforms For people that want to port this commit to other platforms below is a list of ZoL commits that this patch depends on: Make zdb results for checkpoint tests consistent |
||
Paul Dagnelie
|
30af21b025 |
Implement Redacted Send/Receive
Redacted send/receive allows users to send subsets of their data to a target system. One possible use case for this feature is to not transmit sensitive information to a data warehousing, test/dev, or analytics environment. Another is to save space by not replicating unimportant data within a given dataset, for example in backup tools like zrepl. Redacted send/receive is a three-stage process. First, a clone (or clones) is made of the snapshot to be sent to the target. In this clone (or clones), all unnecessary or unwanted data is removed or modified. This clone is then snapshotted to create the "redaction snapshot" (or snapshots). Second, the new zfs redact command is used to create a redaction bookmark. The redaction bookmark stores the list of blocks in a snapshot that were modified by the redaction snapshot(s). Finally, the redaction bookmark is passed as a parameter to zfs send. When sending to the snapshot that was redacted, the redaction bookmark is used to filter out blocks that contain sensitive or unwanted information, and those blocks are not included in the send stream. When sending from the redaction bookmark, the blocks it contains are considered as candidate blocks in addition to those blocks in the destination snapshot that were modified since the creation_txg of the redaction bookmark. This step is necessary to allow the target to rehydrate data in the case where some blocks are accidentally or unnecessarily modified in the redaction snapshot. The changes to bookmarks to enable fast space estimation involve adding deadlists to bookmarks. There is also logic to manage the life cycles of these deadlists. The new size estimation process operates in cases where previously an accurate estimate could not be provided. In those cases, a send is performed where no data blocks are read, reducing the runtime significantly and providing a byte-accurate size estimate. Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed-by: Matt Ahrens <mahrens@delphix.com> Reviewed-by: Prashanth Sreenivasa <pks@delphix.com> Reviewed-by: John Kennedy <john.kennedy@delphix.com> Reviewed-by: George Wilson <george.wilson@delphix.com> Reviewed-by: Chris Williamson <chris.williamson@delphix.com> Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com> Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com> Reviewed-by: Prakash Surya <prakash.surya@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes #7958 |
||
Brian Behlendorf
|
1b939560be
|
Add TRIM support
UNMAP/TRIM support is a frequently-requested feature to help prevent performance from degrading on SSDs and on various other SAN-like storage back-ends. By issuing UNMAP/TRIM commands for sectors which are no longer allocated the underlying device can often more efficiently manage itself. This TRIM implementation is modeled on the `zpool initialize` feature which writes a pattern to all unallocated space in the pool. The new `zpool trim` command uses the same vdev_xlate() code to calculate what sectors are unallocated, the same per- vdev TRIM thread model and locking, and the same basic CLI for a consistent user experience. The core difference is that instead of writing a pattern it will issue UNMAP/TRIM commands for those extents. The zio pipeline was updated to accommodate this by adding a new ZIO_TYPE_TRIM type and associated spa taskq. This new type makes is straight forward to add the platform specific TRIM/UNMAP calls to vdev_disk.c and vdev_file.c. These new ZIO_TYPE_TRIM zios are handled largely the same way as ZIO_TYPE_READs or ZIO_TYPE_WRITEs. This makes it possible to largely avoid changing the pipieline, one exception is that TRIM zio's may exceed the 16M block size limit since they contain no data. In addition to the manual `zpool trim` command, a background automatic TRIM was added and is controlled by the 'autotrim' property. It relies on the exact same infrastructure as the manual TRIM. However, instead of relying on the extents in a metaslab's ms_allocatable range tree, a ms_trim tree is kept per metaslab. When 'autotrim=on', ranges added back to the ms_allocatable tree are also added to the ms_free tree. The ms_free tree is then periodically consumed by an autotrim thread which systematically walks a top level vdev's metaslabs. Since the automatic TRIM will skip ranges it considers too small there is value in occasionally running a full `zpool trim`. This may occur when the freed blocks are small and not enough time was allowed to aggregate them. An automatic TRIM and a manual `zpool trim` may be run concurrently, in which case the automatic TRIM will yield to the manual TRIM. Reviewed-by: Jorgen Lundman <lundman@lundman.net> Reviewed-by: Tim Chase <tim@chase2k.com> Reviewed-by: Matt Ahrens <mahrens@delphix.com> Reviewed-by: George Wilson <george.wilson@delphix.com> Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com> Contributions-by: Saso Kiselkov <saso.kiselkov@nexenta.com> Contributions-by: Tim Chase <tim@chase2k.com> Contributions-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8419 Closes #598 |
||
George Wilson
|
619f097693 |
OpenZFS 9102 - zfs should be able to initialize storage devices
PROBLEM ======== The first access to a block incurs a performance penalty on some platforms (e.g. AWS's EBS, VMware VMDKs). Therefore we recommend that volumes are "thick provisioned", where supported by the platform (VMware). This can create a large delay in getting a new virtual machines up and running (or adding storage to an existing Engine). If the thick provision step is omitted, write performance will be suboptimal until all blocks on the LUN have been written. SOLUTION ========= This feature introduces a way to 'initialize' the disks at install or in the background to make sure we don't incur this first read penalty. When an entire LUN is added to ZFS, we make all space available immediately, and allow ZFS to find unallocated space and zero it out. This works with concurrent writes to arbitrary offsets, ensuring that we don't zero out something that has been (or is in the middle of being) written. This scheme can also be applied to existing pools (affecting only free regions on the vdev). Detailed design: - new subcommand:zpool initialize [-cs] <pool> [<vdev> ...] - start, suspend, or cancel initialization - Creates new open-context thread for each vdev - Thread iterates through all metaslabs in this vdev - Each metaslab: - select a metaslab - load the metaslab - mark the metaslab as being zeroed - walk all free ranges within that metaslab and translate them to ranges on the leaf vdev - issue a "zeroing" I/O on the leaf vdev that corresponds to a free range on the metaslab we're working on - continue until all free ranges for this metaslab have been "zeroed" - reset/unmark the metaslab being zeroed - if more metaslabs exist, then repeat above tasks. - if no more metaslabs, then we're done. - progress for the initialization is stored on-disk in the vdev’s leaf zap object. The following information is stored: - the last offset that has been initialized - the state of the initialization process (i.e. active, suspended, or canceled) - the start time for the initialization - progress is reported via the zpool status command and shows information for each of the vdevs that are initializing Porting notes: - Added zfs_initialize_value module parameter to set the pattern written by "zpool initialize". - Added zfs_vdev_{initializing,removal}_{min,max}_active module options. Authored by: George Wilson <george.wilson@delphix.com> Reviewed by: John Wren Kennedy <john.kennedy@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed by: Prakash Surya <prakash.surya@delphix.com> Reviewed by: loli10K <ezomori.nozomu@gmail.com> Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov> Approved by: Richard Lowe <richlowe@richlowe.net> Signed-off-by: Tim Chase <tim@chase2k.com> Ported-by: Tim Chase <tim@chase2k.com> OpenZFS-issue: https://www.illumos.org/issues/9102 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c3963210eb Closes #8230 |
||
Paul Dagnelie
|
0391690583 |
Refactor dmu_recv into its own file
This change moves the bottom half of dmu_send.c (where the receive logic is kept) into a new file, dmu_recv.c, and does similarly for receive-related changes in header files. Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes #7982 |
||
Don Brady
|
e8bcb693d6 |
Add zfs module feature and property info to sysfs
This extends our sysfs '/sys/module/zfs' entry to include feature and property attributes. The primary consumer of this information is user processes, like the zfs CLI, that need to know what the current loaded ZFS module supports. The libzfs binary will consult this information when instantiating the zfs and zpool property tables and the pool features table. This introduces 4 kernel objects (dirs) into '/sys/module/zfs' with corresponding attributes (files): features.runtime features.pool properties.dataset properties.pool Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Don Brady <don.brady@delphix.com> Closes #7706 |
||
Serapheim Dimitropoulos
|
a448a2557e |
Introduce read/write kstats per dataset
The following patch introduces a few statistics on reads and writes grouped by dataset. These statistics are implemented as kstats (backed by aggregate sums for performance) and can be retrieved by using the dataset objset ID number. The motivation for this change is to provide some preliminary analytics on dataset usage/performance. Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com> Closes #7705 |
||
Serapheim Dimitropoulos
|
d2734cce68 |
OpenZFS 9166 - zfs storage pool checkpoint
Details about the motivation of this feature and its usage can be found in this blogpost: https://sdimitro.github.io/post/zpool-checkpoint/ A lightning talk of this feature can be found here: https://www.youtube.com/watch?v=fPQA8K40jAM Implementation details can be found in big block comment of spa_checkpoint.c Side-changes that are relevant to this commit but not explained elsewhere: * renames members of "struct metaslab trees to be shorter without losing meaning * space_map_{alloc,truncate}() accept a block size as a parameter. The reason is that in the current state all space maps that we allocate through the DMU use a global tunable (space_map_blksz) which defauls to 4KB. This is ok for metaslab space maps in terms of bandwirdth since they are scattered all over the disk. But for other space maps this default is probably not what we want. Examples are device removal's vdev_obsolete_sm or vdev_chedkpoint_sm from this review. Both of these have a 1:1 relationship with each vdev and could benefit from a bigger block size. Porting notes: * The part of dsl_scan_sync() which handles async destroys has been moved into the new dsl_process_async_destroys() function. * Remove "VERIFY(!(flags & FWRITE))" in "kernel.c" so zhack can write to block device backed pools. * ZTS: * Fix get_txg() in zpool_sync_001_pos due to "checkpoint_txg". * Don't use large dd block sizes on /dev/urandom under Linux in checkpoint_capacity. * Adopt Delphix-OS's setting of 4 (spa_asize_inflation = SPA_DVAS_PER_BP + 1) for the checkpoint_capacity test to speed its attempts to fill the pool * Create the base and nested pools with sync=disabled to speed up the "setup" phase. * Clear labels in test pool between checkpoint tests to avoid duplicate pool issues. * The import_rewind_device_replaced test has been marked as "known to fail" for the reasons listed in its DISCLAIMER. * New module parameters: zfs_spa_discard_memory_limit, zfs_remove_max_bytes_pause (not documented - debugging only) vdev_max_ms_count (formerly metaslabs_per_vdev) vdev_min_ms_count Authored by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: John Kennedy <john.kennedy@delphix.com> Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov> Approved by: Richard Lowe <richlowe@richlowe.net> Ported-by: Tim Chase <tim@chase2k.com> Signed-off-by: Tim Chase <tim@chase2k.com> OpenZFS-issue: https://illumos.org/issues/9166 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7159fdb8 Closes #7570 |
||
Paul Dagnelie
|
37fb3e4318 |
OpenZFS 8484 - Implement aggregate sum and use for arc counters
In pursuit of improving performance on multi-core systems, we should implements fanned out counters and use them to improve the performance of some of the arc statistics. These stats are updated extremely frequently, and can consume a significant amount of CPU time. Authored by: Paul Dagnelie <pcd@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Approved by: Dan McDonald <danmcd@joyent.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Ported-by: Paul Dagnelie <pcd@delphix.com> OpenZFS-issue: https://www.illumos.org/issues/8484 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7028a8b92b7 Issue #3752 Closes #7462 |
||
Serapheim Dimitropoulos
|
9d5b524597 |
OpenZFS 9079 - race condition in starting and ending condensing thread for indirect vdevs
The timeline of the race condition is the following: [1] Thread A is about to finish condesing the first vdev in spa_condense_indirect_thread(), so it calls the spa_condense_indirect_complete_sync() sync task which sets the spa_condensing_indirect field to NULL. Waiting for the sync task to finish, thread A sleeps until the txg is done. When this happens, thread A will acquire spa_async_lock and set spa_condense_thread to NULL. [2] While thread A waits for the txg to finish, thread B which is running spa_sync() checks whether it should condense the second vdev in vdev_indirect_should_condense() by checking the spa_condensing_indirect field which was set to NULL by spa_condense_indirect_thread() from thread A. So it goes on and tries to spawn a new condensing thread in spa_condense_indirect_start_sync() and the aforementioned assertions fails because thread A has not set spa_condense_thread to NULL (which is basically the last thing it does before returning). The main issue here is that we rely on both spa_condensing_indirect and spa_condense_thread to signify whether a condensing thread is running. Ideally we would only use one throughout the codebase. In addition, for managing spa_condense_thread we currently use spa_async_lock which basically tights condensing to scrubing when it comes to pausing and resuming those actions during spa export. This commit introduces the ZTHR infrastructure, which is basically threads created during spa_load()/spa_create() and exist until we export or destroy the pool. ZTHRs sleep the majority of the time, until they are notified to wake up and do some predefined type of work. In the context of the current bug, a zthr to does the condensing of indirect mappings replacing the older code that used bare kthreads. When a pool is created, the condensing zthr is spawned but sleeps right away, until it is awaken by a signal from spa_sync(). If an existing pool is loaded, the condensing zthr looks if there is anything to condense before going to sleep, in case we were condensing mappings in the pool before it got exported. The benefits of this solution are the following: - The current bug is fixed - spa_condensing_indirect is the sole indicator of whether we are currently condensing or not - condensing is more decoupled from the spa_async_thread related functionality. As a final note, this commit also sets up the path on upstreaming other features that use the ZTHR code like zpool checkpoint and fast clone deletion. Authored by: Serapheim Dimitropoulos <serapheim@delphix.com> Reviewed by: Matt Ahrens <mahrens@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org> Ported-by: Tim Chase <tim@chase2k.com> OpenZFS-issue: https://illumos.org/issues/9079 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3dc606ee Closes #6900 |
||
Matthew Ahrens
|
a1d477c24c |
OpenZFS 7614, 9064 - zfs device evacuation/removal
OpenZFS 7614 - zfs device evacuation/removal OpenZFS 9064 - remove_mirror should wait for device removal to complete This project allows top-level vdevs to be removed from the storage pool with "zpool remove", reducing the total amount of storage in the pool. This operation copies all allocated regions of the device to be removed onto other devices, recording the mapping from old to new location. After the removal is complete, read and free operations to the removed (now "indirect") vdev must be remapped and performed at the new location on disk. The indirect mapping table is kept in memory whenever the pool is loaded, so there is minimal performance overhead when doing operations on the indirect vdev. The size of the in-memory mapping table will be reduced when its entries become "obsolete" because they are no longer used by any block pointers in the pool. An entry becomes obsolete when all the blocks that use it are freed. An entry can also become obsolete when all the snapshots that reference it are deleted, and the block pointers that reference it have been "remapped" in all filesystems/zvols (and clones). Whenever an indirect block is written, all the block pointers in it will be "remapped" to their new (concrete) locations if possible. This process can be accelerated by using the "zfs remap" command to proactively rewrite all indirect blocks that reference indirect (removed) vdevs. Note that when a device is removed, we do not verify the checksum of the data that is copied. This makes the process much faster, but if it were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be possible to copy the wrong data, when we have the correct data on e.g. the other side of the mirror. At the moment, only mirrors and simple top-level vdevs can be removed and no removal is allowed if any of the top-level vdevs are raidz. Porting Notes: * Avoid zero-sized kmem_alloc() in vdev_compact_children(). The device evacuation code adds a dependency that vdev_compact_children() be able to properly empty the vdev_child array by setting it to NULL and zeroing vdev_children. Under Linux, kmem_alloc() and related functions return a sentinel pointer rather than NULL for zero-sized allocations. * Remove comment regarding "mpt" driver where zfs_remove_max_segment is initialized to SPA_MAXBLOCKSIZE. Change zfs_condense_indirect_commit_entry_delay_ticks to zfs_condense_indirect_commit_entry_delay_ms for consistency with most other tunables in which delays are specified in ms. * ZTS changes: Use set_tunable rather than mdb Use zpool sync as appropriate Use sync_pool instead of sync Kill jobs during test_removal_with_operation to allow unmount/export Don't add non-disk names such as "mirror" or "raidz" to $DISKS Use $TEST_BASE_DIR instead of /tmp Increase HZ from 100 to 1000 which is more common on Linux removal_multiple_indirection.ksh Reduce iterations in order to not time out on the code coverage builders. removal_resume_export: Functionally, the test case is correct but there exists a race where the kernel thread hasn't been fully started yet and is not visible. Wait for up to 1 second for the removal thread to be started before giving up on it. Also, increase the amount of data copied in order that the removal not finish before the export has a chance to fail. * MMP compatibility, the concept of concrete versus non-concrete devices has slightly changed the semantics of vdev_writeable(). Update mmp_random_leaf_impl() accordingly. * Updated dbuf_remap() to handle the org.zfsonlinux:large_dnode pool feature which is not supported by OpenZFS. * Added support for new vdev removal tracepoints. * Test cases removal_with_zdb and removal_condense_export have been intentionally disabled. When run manually they pass as intended, but when running in the automated test environment they produce unreliable results on the latest Fedora release. They may work better once the upstream pool import refectoring is merged into ZoL at which point they will be re-enabled. Authored by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Alex Reece <alex@delphix.com> Reviewed-by: George Wilson <george.wilson@delphix.com> Reviewed-by: John Kennedy <john.kennedy@delphix.com> Reviewed-by: Prakash Surya <prakash.surya@delphix.com> Reviewed by: Richard Laager <rlaager@wiktel.com> Reviewed by: Tim Chase <tim@chase2k.com> Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov> Approved by: Garrett D'Amore <garrett@damore.org> Ported-by: Tim Chase <tim@chase2k.com> Signed-off-by: Tim Chase <tim@chase2k.com> OpenZFS-issue: https://www.illumos.org/issues/7614 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f539f1eb Closes #6900 |
||
Tom Caputi
|
cf63739191 |
QAT support for AES-GCM
This patch adds support for acceleration of AES-GCM encryption with Intel Quick Assist Technology. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Chengfeix Zhu <chengfeix.zhu@intel.com> Signed-off-by: Weigang Li <weigang.li@intel.com> Signed-off-by: Tom Caputi <tcaputi@datto.com> Closes #7282 |
||
Chris Williamson
|
d99a015343 |
OpenZFS 7431 - ZFS Channel Programs
Authored by: Chris Williamson <chris.williamson@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: John Kennedy <john.kennedy@delphix.com> Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org> Ported-by: Don Brady <don.brady@delphix.com> Ported-by: John Kennedy <john.kennedy@delphix.com> OpenZFS-issue: https://www.illumos.org/issues/7431 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/dfc11533 Porting Notes: * The CLI long option arguments for '-t' and '-m' don't parse on linux * Switched from kmem_alloc to vmem_alloc in zcp_lua_alloc * Lua implementation is built as its own module (zlua.ko) * Lua headers consumed directly by zfs code moved to 'include/sys/lua/' * There is no native setjmp/longjump available in stock Linux kernel. Brought over implementations from illumos and FreeBSD * The get_temporary_prop() was adapted due to VFS platform differences * Use of inline functions in lua parser to reduce stack usage per C call * Skip some ZFS Test Suite ZCP tests on sparc64 to avoid stack overflow |
||
Brian Behlendorf
|
fed90353d7
|
Support -fsanitize=address with --enable-asan
When --enable-asan is provided to configure then build all user space components with fsanitize=address. For kernel support use the Linux KASAN feature instead. https://github.com/google/sanitizers/wiki/AddressSanitizer When using gcc version 4.8 any test case which intentionally generates a core dump will fail when using --enable-asan. The default behavior is to disable core dumps and only newer versions allow this behavior to be controled at run time with the ASAN_OPTIONS environment variable. Additionally, this patch includes some build system cleanup. * Rules.am updated to set the minimum AM_CFLAGS, AM_CPPFLAGS, and AM_LDFLAGS. Any additional flags should be added on a per-Makefile basic. The --enable-debug and --enable-asan options apply to all user space binaries and libraries. * Compiler checks consolidated in always-compiler-options.m4 and renamed for consistency. * -fstack-check compiler flag was removed, this functionality is provided by asan when configured with --enable-asan. * Split DEBUG_CFLAGS in to DEBUG_CFLAGS, DEBUG_CPPFLAGS, and DEBUG_LDFLAGS. * Moved default kernel build flags in to module/Makefile.in and split in to ZFS_MODULE_CFLAGS and ZFS_MODULE_CPPFLAGS. These flags are set with the standard ccflags-y kbuild mechanism. * -Wframe-larger-than checks applied only to binaries or libraries which include source files which are built in both user space and kernel space. This restriction is relaxed for user space only utilities. * -Wno-unused-but-set-variable applied only to libzfs and libzpool. The remaining warnings are the result of an ASSERT using a variable when is always declared. * -D_POSIX_PTHREAD_SEMANTICS and -D__EXTENSIONS__ dropped because they are Solaris specific and thus not needed. * Ensure $GDB is defined as gdb by default in zloop.sh. Signed-off-by: DHE <git@dehacked.net> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #7027 |
||
Brian Behlendorf
|
c28a67733c
|
Suppress incorrect objtool warnings
Suppress incorrect warnings from versions of objtool which are not aware of x86 EVEX prefix instructions used for AVX512. module/zfs/vdev_raidz_math_avx512bw.o: warning: objtool: <func+offset>: can't find jump dest instruction at .text Reviewed-by: Don Brady <don.brady@delphix.com> Reviewed-by: George Melikov <mail@gmelikov.ru> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #6928 |
||
Tom Caputi
|
4807c0badb |
Encryption patch follow-up
* PBKDF2 implementation changed to OpenSSL implementation. * HKDF implementation moved to its own file and tests added to ensure correctness. * Removed libzfs's now unnecessary dependency on libzpool and libicp. * Ztest can now create and test encrypted datasets. This is currently disabled until issue #6526 is resolved, but otherwise functions as advertised. * Several small bug fixes discovered after enabling ztest to run on encrypted datasets. * Fixed coverity defects added by the encryption patch. * Updated man pages for encrypted send / receive behavior. * Fixed a bug where encrypted datasets could receive DRR_WRITE_EMBEDDED records. * Minor code cleanups / consolidation. Signed-off-by: Tom Caputi <tcaputi@datto.com> |
||
Tom Caputi
|
b525630342 |
Native Encryption for ZFS on Linux
This change incorporates three major pieces: The first change is a keystore that manages wrapping and encryption keys for encrypted datasets. These commands mostly involve manipulating the new DSL Crypto Key ZAP Objects that live in the MOS. Each encrypted dataset has its own DSL Crypto Key that is protected with a user's key. This level of indirection allows users to change their keys without re-encrypting their entire datasets. The change implements the new subcommands "zfs load-key", "zfs unload-key" and "zfs change-key" which allow the user to manage their encryption keys and settings. In addition, several new flags and properties have been added to allow dataset creation and to make mounting and unmounting more convenient. The second piece of this patch provides the ability to encrypt, decyrpt, and authenticate protected datasets. Each object set maintains a Merkel tree of Message Authentication Codes that protect the lower layers, similarly to how checksums are maintained. This part impacts the zio layer, which handles the actual encryption and generation of MACs, as well as the ARC and DMU, which need to be able to handle encrypted buffers and protected data. The last addition is the ability to do raw, encrypted sends and receives. The idea here is to send raw encrypted and compressed data and receive it exactly as is on a backup system. This means that the dataset on the receiving system is protected using the same user key that is in use on the sending side. By doing so, datasets can be efficiently backed up to an untrusted system without fear of data being compromised. Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jorgen Lundman <lundman@lundman.net> Signed-off-by: Tom Caputi <tcaputi@datto.com> Closes #494 Closes #5769 |
||
Brian Behlendorf
|
46364cb2f3 |
Add libtpool (thread pools)
OpenZFS provides a library called tpool which implements thread pools for user space applications. Porting this library means the zpool utility no longer needs to borrow the kernel mutex and taskq interfaces from libzpool. This code was updated to use the tpool library which behaves in a very similar fashion. Porting libtpool was relatively straight forward and minimal modifications were needed. The core changes were: * Fully convert the library to use pthreads. * Updated signal handling. * lmalloc/lfree converted to calloc/free * Implemented portable pthread_attr_clone() function. Finally, update the build system such that libzpool.so is no longer linked in to zfs(8), zpool(8), etc. All that is required is libzfs to which the zcommon soures were added (which is the way it always should have been). Removing the libzpool dependency resulted in several build issues which needed to be resolved. * Moved zfeature support to module/zcommon/zfeature_common.c * Moved ratelimiting to to module/zfs/zfs_ratelimit.c * Moved get_system_hostid() to lib/libspl/gethostid.c * Removed use of cmn_err() in zcommon source * Removed dprintf_setup() call from zpool_main.c and zfs_main.c * Removed highbit() and lowbit() * Removed unnecessary library dependencies from Makefiles * Removed fletcher-4 kstat in user space * Added sha2 support explicitly to libzfs * Added highbit64() and lowbit64() to zpool_util.c Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #6442 |
||
Olaf Faaland
|
379ca9cf2b |
Multi-modifier protection (MMP)
Add multihost=on|off pool property to control MMP. When enabled a new thread writes uberblocks to the last slot in each label, at a set frequency, to indicate to other hosts the pool is actively imported. These uberblocks are the last synced uberblock with an updated timestamp. Property defaults to off. During tryimport, find the "best" uberblock (newest txg and timestamp) repeatedly, checking for change in the found uberblock. Include the results of the activity test in the config returned by tryimport. These results are reported to user in "zpool import". Allow the user to control the period between MMP writes, and the duration of the activity test on import, via a new module parameter zfs_multihost_interval. The period is specified in milliseconds. The activity test duration is calculated from this value, and from the mmp_delay in the "best" uberblock found initially. Add a kstat interface to export statistics about Multiple Modifier Protection (MMP) updates. Include the last synced txg number, the timestamp, the delay since the last MMP update, the VDEV GUID, the VDEV label that received the last MMP update, and the VDEV path. Abbreviated output below. $ cat /proc/spl/kstat/zfs/mypool/multihost 31 0 0x01 10 880 105092382393521 105144180101111 txg timestamp mmp_delay vdev_guid vdev_label vdev_path 20468 261337 250274925 68396651780 3 /dev/sda 20468 261339 252023374 6267402363293 1 /dev/sdc 20468 261340 252000858 6698080955233 1 /dev/sdx 20468 261341 251980635 783892869810 2 /dev/sdy 20468 261342 253385953 8923255792467 3 /dev/sdd 20468 261344 253336622 042125143176 0 /dev/sdab 20468 261345 253310522 1200778101278 2 /dev/sde 20468 261346 253286429 0950576198362 2 /dev/sdt 20468 261347 253261545 96209817917 3 /dev/sds 20468 261349 253238188 8555725937673 3 /dev/sdb Add a new tunable zfs_multihost_history to specify the number of MMP updates to store history for. By default it is set to zero meaning that no MMP statistics are stored. When using ztest to generate activity, for automated tests of the MMP function, some test functions interfere with the test. For example, the pool is exported to run zdb and then imported again. Add a new ztest function, "-M", to alter ztest behavior to prevent this. Add new tests to verify the new functionality. Tests provided by Giuseppe Di Natale. Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov> Reviewed-by: Ned Bass <bass6@llnl.gov> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Closes #745 Closes #6279 |
||
wli5
|
6a9d635998 |
GZIP compression offloading with QAT accelerator
This patch implement the hardware accelerator method in GZIP compression in ZFS. When the ZFS pool is enabled GZIP compression, the compression API will be automatically transferred to the hardware accelerator to free up CPU resource and speed up the compression time. * To enable Intel QAT hardware acceleration in ZOL you need to have QAT hardware and the driver installed: * QAT hardware DH8950: http://ark.intel.com/products/79483/Intel-QuickAssist-Adapter-8950 * QAT driver: https://01.org/intel-quickassist-technology * Start QAT driver in your system: service qat_service start * Enable QAT in ZFS, e.g.: ./configure --with-qat=<qat-driver-path>/QAT1.6 make * Set GZIP compression in ZFS dataset: zfs set compression = gzip <dataset> * Get QAT hardware statistics by: cat /proc/spl/kstat/zfs/qat * To disable QAT in ZFS: insmod zfs.ko zfs_qat_disable=1 Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com> Signed-off-by: Weigang Li <weigang.li@intel.com> Closes #5846 |
||
David Quigley
|
a6255b7fce | DLPX-44812 integrate EP-220 large memory scalability | ||
Romain Dolbeau
|
7f547f85fe |
Add parity generation/rebuild using AVX-512 for x86-64
avx512f should work on all AVX512 hardware, since it only uses Foundation instructions. avx512bw should be faster on hardware supporting the AVW512BW extension. We can use full-width pshufb (instead of relying on the 256 bits AVX2 pshufb). As a side-effect, the code is also unrolled more. Reviewed-by: Richard Laager <rlaager@wiktel.com> Reviewed-by: Gvozden Neskovic <neskovic@gmail.com> Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Romain Dolbeau <romain.github@dolbeau.name> Closes #5219 |
||
Tony Hutter
|
3c67d83a8a |
OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported by: Tony Hutter <hutter2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/4185
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45818ee
Porting Notes:
This code is ported on top of the Illumos Crypto Framework code:
|
||
Romain Dolbeau
|
62a65a654e |
Add parity generation/rebuild using 128-bits NEON for Aarch64
This re-use the framework established for SSE2, SSSE3 and AVX2. However, GCC is using FP registers on Aarch64, so unlike SSE/AVX2 we can't rely on the registers being left alone between ASM statements. So instead, the NEON code uses C variables and GCC extended ASM syntax. Note that since the kernel explicitly disable vector registers, they have to be locally re-enabled explicitly. As we use the variable's number to define the symbolic name, and GCC won't allow duplicate symbolic names, numbers have to be unique. Even when the code is not going to be used (e.g. the case for 4 registers when using the macro with only 2). Only the actually used variables should be declared, otherwise the build will fails in debug mode. This requires the replacement of the XOR(X,X) syntax by a new ZERO(X) macro, which does the same thing but without repeating the argument. And perhaps someday there will be a machine where there is a more efficient way to zero a register than XOR with itself. This affects scalar, SSE2, SSSE3 and AVX2 as they need the new macro. It's possible to write faster implementations (different scheduling, different unrolling, interleaving NEON and scalar, ...) for various cores, but this one has the advantage of fitting in the current state of the code, and thus is likely easier to review/check/merge. The only difference between aarch64-neon and aarch64-neonx2 is that aarch64-neonx2 unroll some functions some more. Reviewed-by: Gvozden Neskovic <neskovic@gmail.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Romain Dolbeau <romain.dolbeau@atos.net> Closes #4801 |
||
Gvozden Neskovic
|
ae25d22235 |
Add RAID-Z routines for SSE2 instruction set, in x86_64 mode.
The patch covers low-end and older x86 CPUs. Parity generation is equivalent to SSSE3 implementation, but reconstruction is somewhat slower. Previous 'sse' implementation is renamed to 'ssse3' to indicate highest instruction set used. Benchmark results: scalar_rec_p 4 720476442 scalar_rec_q 4 187462804 scalar_rec_r 4 138996096 scalar_rec_pq 4 140834951 scalar_rec_pr 4 129332035 scalar_rec_qr 4 81619194 scalar_rec_pqr 4 53376668 sse2_rec_p 4 2427757064 sse2_rec_q 4 747120861 sse2_rec_r 4 499871637 sse2_rec_pq 4 522403710 sse2_rec_pr 4 464632780 sse2_rec_qr 4 319124434 sse2_rec_pqr 4 205794190 ssse3_rec_p 4 2519939444 ssse3_rec_q 4 1003019289 ssse3_rec_r 4 616428767 ssse3_rec_pq 4 706326396 ssse3_rec_pr 4 570493618 ssse3_rec_qr 4 400185250 ssse3_rec_pqr 4 377541245 original_rec_p 4 691658568 original_rec_q 4 195510948 original_rec_r 4 26075538 original_rec_pq 4 103087368 original_rec_pr 4 15767058 original_rec_qr 4 15513175 original_rec_pqr 4 10746357 Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #4783 |
||
Gvozden Neskovic
|
ab9f4b0b82 |
SIMD implementation of vdev_raidz generate and reconstruct routines
This is a new implementation of RAIDZ1/2/3 routines using x86_64 scalar, SSE, and AVX2 instruction sets. Included are 3 parity generation routines (P, PQ, and PQR) and 7 reconstruction routines, for all RAIDZ level. On module load, a quick benchmark of supported routines will select the fastest for each operation and they will be used at runtime. Original implementation is still present and can be selected via module parameter. Patch contains: - specialized gen/rec routines for all RAIDZ levels, - new scalar raidz implementation (unrolled), - two x86_64 SIMD implementations (SSE and AVX2 instructions sets), - fastest routines selected on module load (benchmark). - cmd/raidz_test - verify and benchmark all implementations - added raidz_test to the ZFS Test Suite New zfs module parameters: - zfs_vdev_raidz_impl (str): selects the implementation to use. On module load, the parameter will only accept first 3 options, and the other implementations can be set once module is finished loading. Possible values for this option are: "fastest" - use the fastest math available "original" - use the original raidz code "scalar" - new scalar impl "sse" - new SSE impl if available "avx2" - new AVX2 impl if available See contents of `/sys/module/zfs/parameters/zfs_vdev_raidz_impl` to get the list of supported values. If an implementation is not supported on the system, it will not be shown. Currently selected option is enclosed in `[]`. Signed-off-by: Gvozden Neskovic <neskovic@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #4328 |
||
Brian Behlendorf
|
f74b821a66 |
Add zfs allow and zfs unallow support
ZFS allows for specific permissions to be delegated to normal users with the `zfs allow` and `zfs unallow` commands. In addition, non- privileged users should be able to run all of the following commands: * zpool [list | iostat | status | get] * zfs [list | get] Historically this functionality was not available on Linux. In order to add it the secpolicy_* functions needed to be implemented and mapped to the equivalent Linux capability. Only then could the permissions on the `/dev/zfs` be relaxed and the internal ZFS permission checks used. Even with this change some limitations remain. Under Linux only the root user is allowed to modify the namespace (unless it's a private namespace). This means the mount, mountpoint, canmount, unmount, and remount delegations cannot be supported with the existing code. It may be possible to add this functionality in the future. This functionality was validated with the cli_user and delegation test cases from the ZFS Test Suite. These tests exhaustively verify each of the supported permissions which can be delegated and ensures only an authorized user can perform it. Two minor bug fixes were required for test-running.py. First, the Timer() object cannot be safely created in a `try:` block when there is an unconditional `finally` block which references it. Second, when running as a normal user also check for scripts using the both the .ksh and .sh suffixes. Finally, existing users who are simulating delegations by setting group permissions on the /dev/zfs device should revert that customization when updating to a version with this change. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Tony Hutter <hutter2@llnl.gov> Closes #362 Closes #434 Closes #4100 Closes #4394 Closes #4410 Closes #4487 |
||
Brian Behlendorf
|
da5e151f20 |
Add pn_alloc()/pn_free() functions
In order to remove the HAVE_PN_UTILS wrappers the pn_alloc() and pn_free() functions must be implemented. The existing illumos implementation were used for this purpose. The `flags` argument which was used in places wrapped by the HAVE_PN_UTILS condition has beed added back to zfs_remove() and zfs_link() functions. This removes a small point of divergence between the ZoL code and upstream. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #4522 |
||
Paul Dagnelie
|
fcff0f35bd |
Illumos 5960, 5925
5960 zfs recv should prefetch indirect blocks 5925 zfs receive -o origin= Reviewed by: Prakash Surya <prakash.surya@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> References: https://www.illumos.org/issues/5960 https://www.illumos.org/issues/5925 https://github.com/illumos/illumos-gate/commit/a2cdcdd Porting notes: - [lib/libzfs/libzfs_sendrecv.c] - |
||
Turbo Fredriksson
|
47a4a6fd5f |
Support parallel build trees (VPATH builds)
Build products from an out of tree build should be written relative to the build directory. Sources should be referred to by their locations in the source directory. This is accomplished by adding the 'src' and 'obj' variables for the module Makefile.am, using relative paths to reference source files, and by setting VPATH when source files are not co-located with the Makefile. This enables the following: $ mkdir build $ cd build $ ../configure \ --with-spl=$HOME/src/git/spl/ \ --with-spl-obj=$HOME/src/git/spl/build $ make -s This change also has the advantage of resolving the following warning which is generated by modern versions of automake. Makefile.am:00: warning: source file 'xxx' is in a subdirectory, Makefile.am:00: but option 'subdir-objects' is disabled Signed-off-by: Turbo Fredriksson <turbo@bayour.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1082 |
||
Prakash Surya
|
ca0bf58d65 |
Illumos 5497 - lock contention on arcs_mtx
Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Richard Elling <richard.elling@richardelling.com> Approved by: Dan McDonald <danmcd@omniti.com> Porting notes and other significant code changes: The illumos 5368 patch (ARC should cache more metadata), which was never picked up by ZoL, is mostly reverted by this patch. Since ZoL relies on the kernel asynchronously calling the shrinker to actually reap memory, the shrinker wakes up arc_reclaim_waiters_cv every time it runs. The arc_adapt_thread() function no longer calls arc_do_user_evicts() since the newly-added arc_user_evicts_thread() calls it periodically. Notable conflicting ZoL commits which conflicted with this patch or whose effects are either duplicated or un-done by this patch: |
||
Prakash Surya
|
0b39b9f96f |
Swap DTRACE_PROBE* with Linux tracepoints
This patch leverages Linux tracepoints from within the ZFS on Linux code base. It also refactors the debug code to bring it back in sync with Illumos. The information exported via tracepoints can be used for a variety of reasons (e.g. debugging, tuning, general exploration/understanding, etc). It is advantageous to use Linux tracepoints as the mechanism to export this kind of information (as opposed to something else) for a number of reasons: * A number of external tools can make use of our tracepoints "automatically" (e.g. perf, systemtap) * Tracepoints are designed to be extremely cheap when disabled * It's one of the "accepted" ways to export this kind of information; many other kernel subsystems use tracepoints too. Unfortunately, though, there are a few caveats as well: * Linux tracepoints appear to only be available to GPL licensed modules due to the way certain kernel functions are exported. Thus, to actually make use of the tracepoints introduced by this patch, one might have to patch and re-compile the kernel; exporting the necessary functions to non-GPL modules. * Prior to upstream kernel version v3.14-rc6-30-g66cc69e, Linux tracepoints are not available for unsigned kernel modules (tracepoints will get disabled due to the module's 'F' taint). Thus, one either has to sign the zfs kernel module prior to loading it, or use a kernel versioned v3.14-rc6-30-g66cc69e or newer. Assuming the above two requirements are satisfied, lets look at an example of how this patch can be used and what information it exposes (all commands run as 'root'): # list all zfs tracepoints available $ ls /sys/kernel/debug/tracing/events/zfs enable filter zfs_arc__delete zfs_arc__evict zfs_arc__hit zfs_arc__miss zfs_l2arc__evict zfs_l2arc__hit zfs_l2arc__iodone zfs_l2arc__miss zfs_l2arc__read zfs_l2arc__write zfs_new_state__mfu zfs_new_state__mru # enable all zfs tracepoints, clear the tracepoint ring buffer $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable $ echo 0 > /sys/kernel/debug/tracing/trace # import zpool called 'tank', inspect tracepoint data (each line was # truncated, they're too long for a commit message otherwise) $ zpool import tank $ cat /sys/kernel/debug/tracing/trace | head -n35 # tracer: nop # # entries-in-buffer/entries-written: 1219/1219 #P:8 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss: hdr... z_rd_int/0-30156 [003] .... 91344.200611: zfs_new_state__mru... lt-zpool-30132 [003] .... 91344.201173: zfs_arc__miss: hdr... z_rd_int/1-30157 [003] .... 91344.201756: zfs_new_state__mru... lt-zpool-30132 [003] .... 91344.201795: zfs_arc__miss: hdr... z_rd_int/2-30158 [003] .... 91344.202099: zfs_new_state__mru... lt-zpool-30132 [003] .... 91344.202126: zfs_arc__hit: hdr ... lt-zpool-30132 [003] .... 91344.202130: zfs_arc__hit: hdr ... lt-zpool-30132 [003] .... 91344.202134: zfs_arc__hit: hdr ... lt-zpool-30132 [003] .... 91344.202146: zfs_arc__miss: hdr... z_rd_int/3-30159 [003] .... 91344.202457: zfs_new_state__mru... lt-zpool-30132 [003] .... 91344.202484: zfs_arc__miss: hdr... z_rd_int/4-30160 [003] .... 91344.202866: zfs_new_state__mru... lt-zpool-30132 [003] .... 91344.202891: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.203034: zfs_arc__miss: hdr... z_rd_iss/1-30149 [001] .... 91344.203749: zfs_new_state__mru... lt-zpool-30132 [001] .... 91344.203789: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.203878: zfs_arc__miss: hdr... z_rd_iss/3-30151 [001] .... 91344.204315: zfs_new_state__mru... lt-zpool-30132 [001] .... 91344.204332: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.204337: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.204352: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.204356: zfs_arc__hit: hdr ... lt-zpool-30132 [001] .... 91344.204360: zfs_arc__hit: hdr ... To highlight the kind of detailed information that is being exported using this infrastructure, I've taken the first tracepoint line from the output above and reformatted it such that it fits in 80 columns: lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss: hdr { dva 0x1:0x40082 birth 15491 cksum0 0x163edbff3a flags 0x640 datacnt 1 type 1 size 2048 spa 3133524293419867460 state_type 0 access 0 mru_hits 0 mru_ghost_hits 0 mfu_hits 0 mfu_ghost_hits 0 l2_hits 0 refcount 1 } bp { dva0 0x1:0x40082 dva1 0x1:0x3000e5 dva2 0x1:0x5a006e cksum 0x163edbff3a:0x75af30b3dd6:0x1499263ff5f2b:0x288bd118815e00 lsize 2048 } zb { objset 0 object 0 level -1 blkid 0 } For the specific tracepoint shown here, 'zfs_arc__miss', data is exported detailing the arc_buf_hdr_t (hdr), blkptr_t (bp), and zbookmark_t (zb) that caused the ARC miss (down to the exact DVA!). This kind of precise and detailed information can be extremely valuable when trying to answer certain kinds of questions. For anybody unfamiliar but looking to build on this, I found the XFS source code along with the following three web links to be extremely helpful: * http://lwn.net/Articles/379903/ * http://lwn.net/Articles/381064/ * http://lwn.net/Articles/383362/ I should also node the more "boring" aspects of this patch: * The ZFS_LINUX_COMPILE_IFELSE autoconf macro was modified to support a sixth paramter. This parameter is used to populate the contents of the new conftest.h file. If no sixth parameter is provided, conftest.h will be empty. * The ZFS_LINUX_TRY_COMPILE_HEADER autoconf macro was introduced. This macro is nearly identical to the ZFS_LINUX_TRY_COMPILE macro, except it has support for a fifth option that is then passed as the sixth parameter to ZFS_LINUX_COMPILE_IFELSE. These autoconf changes were needed to test the availability of the Linux tracepoint macros. Due to the odd nature of the Linux tracepoint macro API, a separate ".h" must be created (the path and filename is used internally by the kernel's define_trace.h file). * The HAVE_DECLARE_EVENT_CLASS autoconf macro was introduced. This is to determine if we can safely enable the Linux tracepoint functionality. We need to selectively disable the tracepoint code due to the kernel exporting certain functions as GPL only. Without this check, the build process will fail at link time. In addition, the SET_ERROR macro was modified into a tracepoint as well. To do this, the 'sdt.h' file was moved into the 'include/sys' directory and now contains a userspace portion and a kernel space portion. The dprintf and zfs_dbgmsg* interfaces are now implemented as tracepoint as well. Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Ned Bass <bass6@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> |
||
Matthew Ahrens
|
9b67f60560 |
Illumos 4757, 4913
4757 ZFS embedded-data block pointers ("zero block compression") 4913 zfs release should not be subject to space checks Reviewed by: Adam Leventhal <ahl@delphix.com> Reviewed by: Max Grossman <max.grossman@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: Christopher Siden <christopher.siden@delphix.com> Reviewed by: Dan McDonald <danmcd@omniti.com> Approved by: Dan McDonald <danmcd@omniti.com> References: https://www.illumos.org/issues/4757 https://www.illumos.org/issues/4913 https://github.com/illumos/illumos-gate/commit/5d7b4d4 Porting notes: For compatibility with the fastpath code the zio_done() function needed to be updated. Because embedded-data block pointers do not require DVAs to be allocated the associated vdevs will not be marked and therefore should not be unmarked. Ported by: Tim Chase <tim@chase2k.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #2544 |
||
Matthew Ahrens
|
da536844d5 |
Illumos 4368, 4369.
4369 implement zfs bookmarks 4368 zfs send filesystems from readonly pools Reviewed by: Christopher Siden <christopher.siden@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org> References: https://www.illumos.org/issues/4369 https://www.illumos.org/issues/4368 https://github.com/illumos/illumos-gate/commit/78f1710 Ported by: Tim Chase <tim@chase2k.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #2530 |
||
George Wilson
|
93cf20764a |
Illumos #4101, #4102, #4103, #4105, #4106
4101 metaslab_debug should allow for fine-grained control 4102 space_maps should store more information about themselves 4103 space map object blocksize should be increased 4105 removing a mirrored log device results in a leaked object 4106 asynchronously load metaslab Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Adam Leventhal <ahl@delphix.com> Reviewed by: Sebastien Roy <seb@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org> Prior to this patch, space_maps were preferred solely based on the amount of free space left in each. Unfortunately, this heuristic didn't contain any information about the make-up of that free space, which meant we could keep preferring and loading a highly fragmented space map that wouldn't actually have enough contiguous space to satisfy the allocation; then unloading that space_map and repeating the process. This change modifies the space_map's to store additional information about the contiguous space in the space_map, so that we can use this information to make a better decision about which space_map to load. This requires reallocating all space_map objects to increase their bonus buffer size sizes enough to fit the new metadata. The above feature can be enabled via a new feature flag introduced by this change: com.delphix:spacemap_histogram In addition to the above, this patch allows the space_map block size to be increase. Currently the block size is set to be 4K in size, which has certain implications including the following: * 4K sector devices will not see any compression benefit * large space_maps require more metadata on-disk * large space_maps require more time to load (typically random reads) Now the space_map block size can adjust as needed up to the maximum size set via the space_map_max_blksz variable. A bug was fixed which resulted in potentially leaking an object when removing a mirrored log device. The previous logic for vdev_remove() did not deal with removing top-level vdevs that are interior vdevs (i.e. mirror) correctly. The problem would occur when removing a mirrored log device, and result in the DTL space map object being leaked; because top-level vdevs don't have DTL space map objects associated with them. References: https://www.illumos.org/issues/4101 https://www.illumos.org/issues/4102 https://www.illumos.org/issues/4103 https://www.illumos.org/issues/4105 https://www.illumos.org/issues/4106 https://github.com/illumos/illumos-gate/commit/0713e23 Porting notes: A handful of kmem_alloc() calls were converted to kmem_zalloc(). Also, the KM_PUSHPAGE and TQ_PUSHPAGE flags were used as necessary. Ported-by: Tim Chase <tim@chase2k.com> Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #2488 |
||
Brian Behlendorf
|
e0b0ca983d |
Add visibility in to cached dbufs
Currently there is no mechanism to inspect which dbufs are being cached by the system. There are some coarse counters in arcstats by they only give a rough idea of what's being cached. This patch aims to improve the current situation by adding a new dbufs kstat. When read this new kstat will walk all cached dbufs linked in to the dbuf_hash. For each dbuf it will dump detailed information about the buffer. It will also dump additional information about the referenced arc buffer and its related dnode. This provides a more complete view in to exactly what is being cached. With this generic infrastructure in place utilities can be written to post-process the data to understand exactly how the caching is working. For example, the data could be processed to show a list of all cached dnodes and how much space they're consuming. Or a similar list could be generated based on dnode type. Many other ways to interpret the data exist based on what kinds of questions you're trying to answer. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Prakash Surya <surya1@llnl.gov> |
||
Prakash Surya
|
1421c89142 |
Add visibility in to arc_read
This change is an attempt to add visibility into the arc_read calls occurring on a system, in real time. To do this, a list was added to the in memory SPA data structure for a pool, with each element on the list corresponding to a call to arc_read. These entries are then exported through the kstat interface, which can then be interpreted in userspace. For each arc_read call, the following information is exported: * A unique identifier (uint64_t) * The time the entry was added to the list (hrtime_t) (*not* wall clock time; relative to the other entries on the list) * The objset ID (uint64_t) * The object number (uint64_t) * The indirection level (uint64_t) * The block ID (uint64_t) * The name of the function originating the arc_read call (char[24]) * The arc_flags from the arc_read call (uint32_t) * The PID of the reading thread (pid_t) * The command or name of thread originating read (char[16]) From this exported information one can see, in real time, exactly what is being read, what function is generating the read, and whether or not the read was found to be already cached. There is still some work to be done, but this should serve as a good starting point. Specifically, dbuf_read's are not accounted for in the currently exported information. Thus, a follow up patch should probably be added to export these calls that never call into arc_read (they only hit the dbuf hash table). In addition, it might be nice to create a utility similar to "arcstat.py" to digest the exported information and display it in a more readable format. Or perhaps, log the information and allow for it to be "replayed" at a later time. Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> |
||
Matthew Ahrens
|
13fe019870 |
Illumos #3464
3464 zfs synctask code needs restructuring Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed by: Adam Leventhal <ahl@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: Christopher Siden <christopher.siden@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org> References: https://www.illumos.org/issues/3464 illumos/illumos-gate@3b2aab1880 Ported-by: Tim Chase <tim@chase2k.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1495 |
||
Eric Dillmann
|
9759c60f1a |
Illumos #3035 LZ4 compression support in ZFS and GRUB
3035 LZ4 compression support in ZFS and GRUB Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Christopher Siden <christopher.siden@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Approved by: Christopher Siden <csiden@delphix.com> References: illumos/illumos-gate@a6f561b4ae https://www.illumos.org/issues/3035 http://wiki.illumos.org/display/illumos/LZ4+Compression+In+ZFS This patch has been slightly modified from the upstream Illumos version to be compatible with Linux. Due to the very limited stack space in the kernel a lz4 workspace kmem cache is used. Since we are using gcc we are also able to take advantage of the gcc optimized __builtin_ctz functions. Support for GRUB has been dropped from this patch. That code is available but those changes will need to made to the upstream GRUB package. Lastly, several hunks of dead code were dropped for clarity. They include the functions real_LZ4_uncompress(), LZ4_compressBound() and the Visual Studio specific hunks wrapped in _MSC_VER. Ported-by: Eric Dillmann <eric@jave.fr> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1217 |
||
Christopher Siden
|
9ae529ec5d |
Illumos #2619 and #2747
2619 asynchronous destruction of ZFS file systems 2747 SPA versioning with zfs feature flags Reviewed by: Matt Ahrens <mahrens@delphix.com> Reviewed by: George Wilson <gwilson@delphix.com> Reviewed by: Richard Lowe <richlowe@richlowe.net> Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com> Approved by: Eric Schrock <Eric.Schrock@delphix.com> References: illumos/illumos-gate@53089ab7c8 illumos/illumos-gate@ad135b5d64 illumos changeset: 13700:2889e2596bd6 https://www.illumos.org/issues/2619 https://www.illumos.org/issues/2747 NOTE: The grub specific changes were not ported. This change must be made to the Linux grub packages. Ported-by: Brian Behlendorf <behlendorf1@llnl.gov> |
||
Etienne Dechamps
|
2ee4a18b2a |
Add script for builtin module building.
This commit introduces a "copy-builtin" script designed to prepare a kernel source tree for building ZFS as a builtin module. The script makes a full copy of all needed files, thus making the kernel source tree fully independent of the zfs source package. To achieve that, some compilation flags (-include, -I) have been moved to module/Makefile. This Makefile is only used when compiling external modules; when compiling builtin modules, a Kbuild file generated by the configure-builtin script is used instead. This makes sure Makefiles inside the kernel source tree does not contain references to the zfs source package. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #851 |
||
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 |
||
Gunnar Beutner
|
055656d4f4 |
Implemented NFS export_operations.
Implemented the required NFS operations for exporting ZFS datasets using the in-kernel NFS daemon. |
||
Brian Behlendorf
|
1efb473f89 |
Add Hooks for Linux File Operations
The Linux specific file operations have all been located in the file zpl_file.c. These functions primarily rely on the reworked zfs_* functions to do their job. They are also responsible for converting the possible Solaris style error codes to negative Linux errors. This first zpl_* commit also includes a common zpl.h header with minimal entries to register the Linux specific hooks. In also adds all the new zpl_* file to the Makefile.in. This is not a standalone commit, you required the following zpl_* commits. |
||
Brian Behlendorf
|
bcf308227c |
Remove zfs_ctldir.[ch]
This code is used for snapshot and heavily leverages Solaris functionality we do not want to reimplement. These files have been removed, including references to them, and will be replaced by a zfs_snap.c/zpl_snap.c implementation which handles snapshots. |
||
Brian Behlendorf
|
6283f55ea1 |
Support custom build directories and move includes
One of the neat tricks an autoconf style project is capable of is allow configurion/building in a directory other than the source directory. The major advantage to this is that you can build the project various different ways while making changes in a single source tree. For example, this project is designed to work on various different Linux distributions each of which work slightly differently. This means that changes need to verified on each of those supported distributions perferably before the change is committed to the public git repo. Using nfs and custom build directories makes this much easier. I now have a single source tree in nfs mounted on several different systems each running a supported distribution. When I make a change to the source base I suspect may break things I can concurrently build from the same source on all the systems each in their own subdirectory. wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz tar -xzf zfs-x.y.z.tar.gz cd zfs-x-y-z ------------------------- run concurrently ---------------------- <ubuntu system> <fedora system> <debian system> <rhel6 system> mkdir ubuntu mkdir fedora mkdir debian mkdir rhel6 cd ubuntu cd fedora cd debian cd rhel6 ../configure ../configure ../configure ../configure make make make make make check make check make check make check This change also moves many of the include headers from individual incude/sys directories under the modules directory in to a single top level include directory. This has the advantage of making the build rules cleaner and logically it makes a bit more sense. |