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* Illumos 6267 - dn_bonus evicted too earlyJustin T. Gibbs2015-10-133-41/+21
| | | | | | | | | | | | | | | | | 6267 dn_bonus evicted too early Reviewed by: Richard Yao <[email protected]> Reviewed by: Xin LI <[email protected]> Reviewed by: Matthew Ahrens <[email protected]> Approved by: Richard Lowe <[email protected]> References: https://www.illumos.org/issues/6267 https://github.com/illumos/illumos-gate/commit/d205810 Signed-off-by: Brian Behlendorf <[email protected]> Ported-by: Ned Bass [email protected] Issue #3865 Issue #3443
* Fix 'arc_c < arc_c_min' panicBrian Behlendorf2015-10-131-1/+2
| | | | | | | | | Strictly enforce keeping 'arc_c >= arc_c_min'. The ASSERTs are left in place to catch this in a debug build but logic has been added to gracefully handle in a production build. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3904
* zfs_inode_update should not call dmu_object_size_from_db under spinlockRichard Yao2015-09-301-2/+4
| | | | | | | | | | | We should never block when holding a spin lock, but zfs_inode_update can block in the critical section of a spin lock in zfs_inode_update: zfs_inode_update -> dmu_object_size_from_db -> zrl_add -> mutex_enter Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #3858
* Remove obsolete zv_lockRichard Yao2015-09-301-2/+0
| | | | | | | | | All users of zv_lock were removed by 37f9dac, but we forgot to remove it. Lets remove it as clean up. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #3858
* Revert "dmu_objset_userquota_get_ids uses dn_bonus unsafely"Brian Behlendorf2015-09-251-17/+3
| | | | | | | | | | | | This reverts commit 5f8e1e850522ee5cd37366427da4b4101a71c8a8. It was determined that this patch introduced the quota regression described in #3789. Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Ned Bass <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #3443 Issue #3789
* Fix synchronous behavior in __vdev_disk_physio()Brian Behlendorf2015-09-251-28/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b39c22b set the READ_SYNC and WRITE_SYNC flags for a bio based on the ZIO_PRIORITY_* flag passed in. This had the unnoticed side-effect of making the vdev_disk_io_start() synchronous for certain I/Os. This in turn resulted in vdev_disk_io_start() being able to re-dispatch zio's which would result in a RCU stalls when a disk was removed from the system. Additionally, this could negatively impact performance and explains the performance regressions reported in both #3829 and #3780. This patch resolves the issue by making the blocking behavior dependent on a 'wait' flag being passed rather than overloading the passed bio flags. Finally, the WRITE_SYNC and READ_SYNC behavior is restricted to non-rotational devices where there is no benefit to queuing to aggregate the I/O. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3652 Issue #3780 Issue #3785 Issue #3817 Issue #3821 Issue #3829 Issue #3832 Issue #3870
* Avoid blocking in arc_reclaim_thread()Brian Behlendorf2015-09-251-11/+4
| | | | | | | | | | | | | | | | | | | | | | As described in the comment above arc_reclaim_thread() it's critical that the reclaim thread be careful about blocking. Just like it must never wait on a hash lock, it must never wait on a task which can in turn wait on the CV in arc_get_data_buf(). This will deadlock, see issue #3822 for full backtraces showing the problem. To resolve this issue arc_kmem_reap_now() has been updated to use the asynchronous arc prune function. This means that arc_prune_async() may now be called while there are still outstanding arc_prune_tasks. However, this isn't a problem because arc_prune_async() already keeps a reference count preventing multiple outstanding tasks per registered consumer. Functionally, this behavior is the same as the counterpart illumos function dnlc_reduce_cache(). Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Tim Chase <[email protected]> Issue #3808 Issue #3834 Issue #3822
* Disable zpl_nr_cached_objects() callbackBrian Behlendorf2015-09-251-14/+1
| | | | | | | | | | | The zpl_nr_cached_objects() function has been disabled because in the current code it doesn't provide any critical functionality and it may result in a deadlock under certain circumstances. However, because we expect to need these hooks in the future this code has not been entirely removed. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3719
* Allow NFS activity to defer snapshot unmountsBrian Behlendorf2015-09-251-2/+13
| | | | | | | | | | Accessing a snapshot via NFS should cause an auto-unmount of that snapshot to be deferred until such as time as the snapshot is idle. This is analogous to the zpl_revalidate logic employed by locally mounted snapshots. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3794
* Linux 4.3 compat: bio_end_io_t / BIO_UPTODATELukas Wunner2015-09-252-17/+16
| | | | | | | | | | | | | | | | | | Commit torvalds/linux@4246a0b63bd8f56a1469b12eafeb875b1041a451 ("block: add a bi_error field to struct bio") dropped the error argument from bio_endio in favor of newly introduced bio->bi_error. This also replaces bio->bi_flags value BIO_UPTODATE. bio_endio was a 3 argument function until Linux 2.6.24, which made it a 2 argument function, and now the prototype has changed yet again to a 1 argument function. Support for pre 2.6.24 kernels was already dropped with 37f9dac592bf ("zvol processing should use struct bio") which assumed the 2 argument version in zvol_request(). Remaining code to support the 3 argument version is hereby removed. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Lukas Wunner <[email protected]> Issue #3799
* Honor xattr=sa dataset propertyNed Bass2015-09-191-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | ZFS incorrectly uses directory-based extended attributes even when xattr=sa is specified as a dataset property or mount option. Support to honor temporary mount options including "xattr" was added in commit 0282c4137e7409e6d85289f4955adf07fac834f5. There are two issues with the mount option handling: * Libzfs has historically included "xattr" in its list of default mount options. This overrides the dataset property, so the dataset is always configured to use directory-based xattrs even when the xattr dataset property is set to off or sa. Address this by removing "xattr" from the set of default mount options in libzfs. * There was no way to enable system attribute-based extended attributes using temporary mount options. Add the mount options "saxattr" and "dirxattr" which enable the xattr behavior their names suggest. This approach has the advantages of mirroring the valid xattr dataset property values and following existing conventions for mount option names. Signed-off-by: Ned Bass <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3787
* Fix NULL as mount(2) syscall data parameterBrian Behlendorf2015-09-191-23/+24
| | | | | | | | | Passing NULL for the mount data should not result in EINVAL. It should be treated as if an empty string were passed and succeed. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Ned Bass <[email protected]> Closes #3771
* Discard on zvols should not exceed the length of a blockRichard Yao2015-09-191-0/+1
| | | | | | | | | | | | 37f9dac592bf5889c3efb305c48ac39b4c7dd140 replaced the end-start calculation with a cached value, but neglected to update it on discard operations. This can cause us to discard data not requested, causing data loss on zvols. Reported-by: Richard Connon <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3798
* Illumos 6214 - zpools going southArne Jansen2015-09-111-20/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | 6214 zpools going south Reviewed by: Igor Kozhukhov <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Dan McDonald <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> References: https://www.illumos.org/issues/6214 http://cr.illumos.org/~webrev/sensille/6214_zpools_going_south/ Porting Notes: Reintroduce b_compress to the l2arc_buf_hdr_t. In commit b9541d6 the compression flags were moved to the generic b_flags in the arc_buf_hdr_t. This is a problem because l2arc_compress_buf() may manipulate the compression flags and this can only be done safely under the hash lock which is not held. See Illumos 6214 for a detailed analysis of the race. HDR_GET_COMPRESS() macro was removed from arc_buf_info(). Ported-by: Brian Behlendorf <[email protected]> Closes #3757
* Prefetch start and end of volumesBrian Behlendorf2015-09-091-0/+17
| | | | | | | | | | | | When adding a zvol to the system prefetch zvol_prefetch_bytes from the start and end of the volume. Prefetching these regions of the volume is desirable because they are likely to be accessed immediately by blkid(8), the kernel scanning for a partition table, or another task which probes the devices. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #3659
* Reintroduce IO accounting on zvols on Linux 3.19+Richard Yao2015-09-091-5/+13
| | | | | | | | | | | | | | zfsonlinux/zfs@e20cd6f7a8922709b1aa2ecefd783390102d79e0 caused us to lose IO accounting on zvols. When I originally wrote that last year, the symbols we needed to maintain IO accounting were GPL exported, but torvalds/linux@394ffa503bc40e32d7f54a9b817264e81ce131b4 provided suitable symbols for restoring this functionality 4 months later. We can call them to restore the IO accounting on Linux 3.19 and later as well as any older kernels where that patch is backported. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3741
* Add dbgmsg kstatBrian Behlendorf2015-09-042-102/+170
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Internally ZFS keeps a small log to facilitate debugging. By default the log is disabled, to enable it set zfs_dbgmsg_enable=1. The contents of the log can be accessed by reading the /proc/spl/kstat/zfs/dbgmsg file. Writing 0 to this proc file clears the log. $ echo 1 >/sys/module/zfs/parameters/zfs_dbgmsg_enable $ echo 0 >/proc/spl/kstat/zfs/dbgmsg $ zpool import tank $ cat /proc/spl/kstat/zfs/dbgmsg 1 0 0x01 -1 0 2492357525542 2525836565501 timestamp message 1441141408 spa=tank async request task=1 1441141408 txg 70 open pool version 5000; software version 5000/5; ... 1441141409 spa=tank async request task=32 1441141409 txg 72 import pool version 5000; software version 5000/5; ... 1441141414 command: lt-zpool import tank Note the zfs_dbgmsg() and dprintf() functions are both now mapped to the same log. As mentioned above the kernel debug log can be accessed though the /proc/spl/kstat/zfs/dbgmsg kstat. For user space consumers log messages are immediately written to stdout after applying the ZFS_DEBUG environment variable. $ ZFS_DEBUG=on ./cmd/ztest/ztest -V Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Ned Bass <[email protected]> Closes #3728
* Support accessing .zfs/snapshot via NFSBrian Behlendorf2015-09-042-0/+126
| | | | | | | | | | | | | | | | | | | | This patch is based on the previous work done by @andrey-ve and @yshui. It triggers the automount by using kern_path() to traverse to the known snapshout mount point. Once the snapshot is mounted NFS can access the contents of the snapshot. Allowing NFS clients to access to the .zfs/snapshot directory would normally mean that a root user on a client mounting an export with 'no_root_squash' would be able to use mkdir/rmdir/mv to manipulate snapshots on the server. To prevent configuration mistakes a zfs_admin_snapshot module option was added which disables the mkdir/rmdir/mv functionally. System administators desiring this functionally must explicitly enable it. Signed-off-by: Brian Behlendorf <[email protected]> Closes #2797 Closes #1655 Closes #616
* Fix invalid fileid for snapshot root dentryAndrey Vesnovaty2015-09-041-0/+10
| | | | | | | | Prevents NFS client from detection of different fileids of snapshot root dentry before & after snapshot mount. Signed-off-by: Andrey Vesnovaty <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]>
* Merge branch 'zvol'Brian Behlendorf2015-09-043-210/+135
|\ | | | | | | | | | | | | | | Performance improvements for zvols. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3720
| * Support secure discard on zvolsRichard Yao2015-09-041-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | Linux 2.6.36 introduced REQ_SECURE to indicate when discards *must* be processed, such that we cannot do optimizations like block alignment. Consequently, the discard semantics prior to 2.6.36 require us to always process unaligned discards. Previously, we would do this optimization regardless. This patch changes things to correctly restrict this optimization to situations where REQ_SECURE exists, but is not included in the flags. Signed-off-by: Richard Yao <[email protected]>
| * zvol processing should use struct bioRichard Yao2015-09-043-204/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Internally, zvols are files exposed through the block device API. This is intended to reduce overhead when things require block devices. However, the ZoL zvol code emulates a traditional block device in that it has a top half and a bottom half. This is an unnecessary source of overhead that does not exist on any other OpenZFS platform does this. This patch removes it. Early users of this patch reported double digit performance gains in IOPS on zvols in the range of 50% to 80%. Comments in the code suggest that the current implementation was done to obtain IO merging from Linux's IO elevator. However, the DMU already does write merging while arc_read() should implicitly merge read IOs because only 1 thread is permitted to fetch the buffer into ARC. In addition, commercial ZFSOnLinux distributions report that regular files are more performant than zvols under the current implementation, and the main consumers of zvols are VMs and iSCSI targets, which have their own elevators to merge IOs. Some minor refactoring allows us to register zfs_request() as our ->make_request() handler in place of the generic_make_request() function. This eliminates the layer of code that broke IO requests on zvols into a top half and a bottom half. This has several benefits: 1. No per zvol spinlocks. 2. No redundant IO elevator processing. 3. Interrupts are disabled only when actually necessary. 4. No redispatching of IOs when all taskq threads are busy. 5. Linux's page out routines will properly block. 6. Many autotools checks become obsolete. An unfortunate consequence of eliminating the layer that generic_make_request() is that we no longer calls the instrumentation hooks for block IO accounting. Those hooks are GPL-exported, so we cannot call them ourselves and consequently, we lose the ability to do IO monitoring via iostat. Since zvols are internally files mapped as block devices, this should be okay. Anyone who is willing to accept the performance penalty for the block IO layer's accounting could use the loop device in between the zvol and its consumer. Alternatively, perf and ftrace likely could be used. Also, tools like latencytop will still work. Tools such as latencytop sometimes provide a better view of performance bottlenecks than the traditional block IO accounting tools do. Lastly, if direct reclaim occurs during spacemap loading and swap is on a zvol, this code will deadlock. That deadlock could already occur with sync=always on zvols. Given that swap on zvols is not yet production ready, this is not a blocker. Signed-off-by: Richard Yao <[email protected]>
* | Prevent reclaim in the traverse prefetch threadTim Chase2015-09-041-0/+2
| | | | | | | | | | | | | | | | | | Reclaim in the traverse prefetch thread, which is run on the system taskq, can overrun the stack. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Tim Chase <[email protected]> Closes #3733
* | Add temporary mount optionsBrian Behlendorf2015-09-033-38/+275
|/ | | | | | | | | | | | | Add the required kernel side infrastructure to parse arbitrary mount options. This enables us to support temporary mount options in largely the same way it is handled on other platforms. See the 'Temporary Mount Point Properties' section of zfs(8) for complete details. Signed-off-by: Brian Behlendorf <[email protected]> Closes #985 Closes #3351
* Dbuf hash table should be sized as is the arc hash tableTim Chase2015-09-021-3/+4
| | | | | | | | | | | Commit 49ddb315066e372f31bda29a5c546a9eccc8b418 added the zfs_arc_average_blocksize parameter to allow control over the size of the arc hash table. The dbuf hash table's size should be determined similarly. Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3721
* Add spa_slop_shift module optionBrian Behlendorf2015-09-021-0/+3
| | | | | | | | | | Allow for easy turning of a pools reserved free space. Previous versions of ZFS (v0.6.4 and earlier) held 1/64 of the pools capacity in reserve. Commits 3d45fdd and 0c60cc3 increased this to 1/32. Setting spa_slop_shift=6 will restore the previous default setting. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3724
* Disable LBA weighting on files and SSDsRichard Yao2015-09-014-2/+16
| | | | | | | | | | | | | | The LBA weighting makes sense on rotational media where the outer tracks have twice the bandwidth of the inner tracks. However, it is detrimental on nonrotational media such as solid state disks, where the only effect is to ensure that metaslabs enter the best-fit allocation behavior sooner, which is detrimental to performance. It also makes no sense on files where the underlying filesystem can arrange things however it wants. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3712
* Check for RW_WRITE_HELD in zfs_inactivetuxoko2015-09-011-3/+10
| | | | | | | | | | | | | | | Before read locking z_teardown_inactive_lock, we need to check if we have already had write lock on it. Otherwise, we would deadlock on ourself when doing rollback: zfs_ioc_rollback ->zfs_suspend_fs (z_teardown_inactive_lock, RW_WRITER) ->zfs_resume_fs->zfs_rezget->zfs_iput_async->iput-> ... ->zfs_inactive (z_teardown_inactive_lock, RW_READER) Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #2869
* Linux 4.2 compat: misc_deregister()Brian Behlendorf2015-09-011-5/+1
| | | | | | | | | The misc_deregister() function was changed to a void return type. Rather than add compatibility code to detect this change simply ignore the return code on all kernels. It was only used to log an informational error message of no real value. Signed-off-by: Brian Behlendorf <[email protected]>
* Linux 3.18 compat: Snapshot auto-mountingBrian Behlendorf2015-08-318-398/+454
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Re-factor the .zfs/snapshot auto-mouting code to take in to account changes made to the upstream kernels. And to lay the groundwork for enabling access to .zfs snapshots via NFS clients. This patch makes the following core improvements. * All actively auto-mounted snapshots are now tracked in two global trees which are indexed by snapshot name and objset id respectively. This allows for fast lookups of any auto-mounted snapshot regardless without needing access to the parent dataset. * Snapshot entries are added to the tree in zfsctl_snapshot_mount(). However, they are now removed from the tree in the context of the unmount process. This eliminates the need complicated error logic in zfsctl_snapshot_unmount() to handle unmount failures. * References are now taken on the snapshot entries in the tree to ensure they always remain valid while a task is outstanding. * The MNT_SHRINKABLE flag is set on the snapshot vfsmount_t right after the auto-mount succeeds. This allows to kernel to unmount idle auto-mounted snapshots if needed removing the need for the zfsctl_unmount_snapshots() function. * Snapshots in active use will not be automatically unmounted. As long as at least one dentry is revalidated every zfs_expire_snapshot/2 seconds the auto-unmount expiration timer will be extended. * Commit torvalds/linux@bafc9b7 caused snapshots auto-mounted by ZFS to be immediately unmounted when the dentry was revalidated. This was a consequence of ZFS invaliding all snapdir dentries to ensure that negative dentries didn't mask new snapshots. This patch modifies the behavior such that only negative dentries are invalidated. This solves the issue and may result in a performance improvement. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3589 Closes #3344 Closes #3295 Closes #3257 Closes #3243 Closes #3030 Closes #2841
* zfsctl: No need to sync ctldir inodesAndrey Vesnovaty2015-08-311-0/+3
| | | | | | | | | | There's no metadata to write to disk for ctldir inodes. So we check if a inode belongs to the ctldir in zpl_commit_metadata, and returns immediately if it is. Signed-off-by: Andrey Vesnovaty <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #2797
* Clear QUEUE_FLAG_ADD_RANDOM on zvolsRichard Yao2015-08-301-0/+3
| | | | | | | | | | | zvols should not be an entropy source for the kernel. Disable it to be consistent with the upstream kernel. torvalds/linux@b277da0a8a594308e17881f4926879bd5fca2a2d Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3713
* Fix small typololi10K2015-08-301-1/+1
| | | | | | | | | | Add a missing space to the zfs_vdev_sync_write_min_active module parameter description. Signed-off-by: loli10K <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3714
* Initialize the taskq entry embedded within struct vdevTim Chase2015-08-301-0/+1
| | | | | | | | | | | | | As part of the stack reduction effort in 50b25b2187134ac7b19cf93bd35a420223f1d343, a zio_t containing a taskq_ent was added to struct vdev_queue which itself is part of struct vdev. The taskq entry should be initialized as is currently done in zio_create() for newly-created bare zio_t object. The rationale is the same as is described in f467b05a265abcfb8e5a3269f79d08f36a58646a. Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3709
* Allow recovery from corrupted snapshot mapsTim Chase2015-08-281-0/+6
| | | | | | | | | | | | | | | | | | If the ZAP object containing a snapshot map is corrupted due to an unrecoverable checksum error or otherwise, dsl_dataset_name() will normally panic the system due to its VERIFY. This patch attempts to allow a recovery avenue from such situations by manufacturing a descriptive snapshot name and then ignoring the error. Scrubbing a pool with this type of corruption will then show the affected object in the error list rather than panicking. The recovery code is only enabled when the zfs_recover module parameter is set. Signed-off-by: Tim Chase <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3705
* Check large block feature flag on volumesBrian Behlendorf2015-08-282-2/+27
| | | | | | | | | | | | | | | Since ZoL allows large blocks to be used by volumes, unlike upstream illumos, the feature flag must be checked prior to volume creation. This is critical because unlike filesystems, volumes will create a object which uses large blocks as part of the create. Therefore, it cannot be safely checked in zfs_check_settable() after the dataset can been created. In addition this patch updates the relevant error messages to use zfs_nicenum() to print the maximum blocksize. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3591
* Limit max_hw_sectors_kb to 16MBrian Behlendorf2015-08-281-1/+1
| | | | | | | | | | | | | | | | When support for large blocks was added DMU_MAX_ACCESS was increased to allow for blocks of up to 16M to fit in a transaction handle. This had the side effect of increasing the max_hw_sectors_kb for volumes, which are scaled off DMU_MAX_ACCESS, to 64M from 10M. This is an issue for volumes which by default use an 8K block size because it results in dmu_buf_hold_array_by_dnode() allocating a 64K array for the dbufs. The solution is to restore the maximum size to ~10M. This patch specifically changes it to 16M which is close enough. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3684
* Linux 4.1 compat: loop device on ZFSChunwei Chen2015-08-244-40/+54
| | | | | | | | | | | | | | | | | | | Starting from Linux 4.1 allows iov_iter with bio_vec to be passed into iter_read/iter_write. Notably, the loop device will pass bio_vec to backend filesystem. However, current ZFS code assumes iovec without any check, so it will always crash when using loop device. With the restructured uio_t, we can safely pass bio_vec in uio_t with UIO_BVEC set. The uio* functions are modified to handle bio_vec case separately. The const uio_iov causes some warning in xuio related stuff, so explicit convert them to non const. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3511 Closes #3640
* Linux 4.2 compat: vfs_rename()Brian Behlendorf2015-08-191-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The spa_config_write() function relies on the classic method of making sure updates to the /etc/zfs/zpool.cache file are atomic. It writes out a temporary version of the file and then uses vn_rename() to switch it in to place. This way there can never exist a partial version of the file, it's all or nothing. Conceptually this is a good strategy and it makes good sense for platforms where it's easy to do a rename within the kernel. Unfortunately, Linux is not one of those platforms. Even doing basic I/O to a file system from within the kernel is strongly discouraged. In order to support this at all the vn_rename() implementation ends up being complex and fragile. So fragile that recent Linux 4.2 changes have broken it. While it is possible to update vn_rename() to work with the latest kernels a better long term strategy is to stop using vn_rename() entirely. Then all this complex, fragile code can be removed. Achieving this is straight forward because config_write() is the only consumer of vn_rename(). This patch reworks spa_config_write() to update the cache file in place. The file will be truncated, written out, and then synced to disk. If an error is encountered the file will be unlinked leaving the system in a consistent state. This does expose a tiny tiny tiny window where a system could crash at exactly the wrong moment could leave a partially written cache file. However, this is highly unlikely because the cache file is 1) infrequently updated, 2) only a few kilobytes in size, and 3) written with a single vn_rdwr() call. If this were to somehow happen it poses no risk to pool. Simply removing the cache file will allow the pool to be imported cleanly. Going forward this will be even less of an issue as we intend to disable the use of a cache file by default. Bottom line not using vn_rename() allows us to make ZoL more robust against upstream kernel changes. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3653
* Handle zap_lookup() failure in ddt_object_load()Brian Behlendorf2015-08-191-3/+4
| | | | | | | | | Failing to lookup a name in the spa_ddt_stat_object should not result in a panic in ddt_object_load(). The error can be safely returned to the caller for handling resulting in a useful user error message. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3370
* Add parenthesis to the ternary operatortuxoko2015-08-191-1/+1
| | | | | | | | | Without the parenthesis, this particular ASSERT will evaluate to "(RW_READER == (!zap->zap_ismicro && fatreader)) ? RW_READER : lti" Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3685
* Update arc_memory_throttle() to check pageoutBrian Behlendorf2015-07-301-7/+37
| | | | | | | | | | | | | | | | | | | | | | | | This brings the behavior of arc_memory_throttle() back in sync with illumos. The updated memory throttling policy roughly goes like this: * Never throttle if more than 10% of memory is free. This threshold is configurable with the zfs_arc_lotsfree_percent module option. * Minimize any throttling of kswapd even when free memory is below the set threshold. Allow it to write out pages as quickly as possible to help alleviate the memory pressure. * Delay all other threads when free memory is below the set threshold in order to avoid compounding the memory pressure. Buffers will be evicted from the ARC to reduce the issue. The Linux specific zfs_arc_memory_throttle_disable module option has been removed in favor of the existing zfs_arc_lotsfree_percent tuning. Setting zfs_arc_lotsfree_percent=0 will have the same effect as zfs_arc_memory_throttle_disable and it was therefore redundant. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3637
* Update arc_available_memory() to check freememBrian Behlendorf2015-07-301-31/+33
| | | | | | | | | | | | | | | | | | | | | | While Linux doesn't provide detailed information about the state of the VM it does provide us total free pages. This information should be incorporated in to the arc_available_memory() calculation rather than solely relying on a signal from direct reclaim. Conceptually this brings arc_available_memory() back in sync with illumos. It is also desirable that the target amount of free memory be tunable on a system. While the default values are expected to work well for most workloads there may be cases where custom values are needed. The zfs_arc_sys_free module option was added for this purpose. zfs_arc_sys_free - The target number of bytes the ARC should leave as free memory on the system. This value can checked in /proc/spl/kstat/zfs/arcstats and setting this module option will override the default value. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3637
* Bound zvol_threads module optionBrian Behlendorf2015-07-291-3/+4
| | | | | | | | | | The zvol_threads module option should be bounded to a reasonable range. The taskq must have at least 1 thread and shouldn't have more than 1,024 at most. The default value of 32 is a reasonable default. Signed-off-by: Brian Behlendorf <[email protected]> Closes #3614
* Fix "BUG: Bad page state" caused by writeback flagChunwei Chen2015-07-291-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | Commit d958324 fixed the deadlock between page lock and range lock by unlocking the page lock before acquiring the range lock. However, this created a new issue #3075. The problem is that if we can't set the write back bit before releasing the page lock. Then other processes will be unaware that the page is under active write back. They may therefore truncate the page, invalidate the page, or not honor the sync semantics. To workaround this problem we re-dirty the page before dropping the page lock. While this doesn't prevent the page from being truncated it does ensure it won't be invalidated. Then the range lock and the page lock are reacquired in the correct deadlock-free order. Once both locks are safely held the page state can be rechecked. If all is well and the page is in the expect state the dirty bit can be removed, the write back bit set, and the page removed from the skip count. If not the page will be handled as appropriate. Signed-off-by: Chunwei Chen <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #3075
* Align thread priority with Linux defaultsBrian Behlendorf2015-07-289-16/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Under Linux filesystem threads responsible for handling I/O are normally created with the maximum priority. Non-I/O filesystem processes run with the default priority. ZFS should adopt the same priority scheme under Linux to maintain good performance and so that it will complete fairly when other Linux filesystems are active. The priorities have been updated to the following: $ ps -eLo rtprio,cls,pid,pri,nice,cmd | egrep 'z_|spl_|zvol|arc|dbu|meta' - TS 10743 19 -20 [spl_kmem_cache] - TS 10744 19 -20 [spl_system_task] - TS 10745 19 -20 [spl_dynamic_tas] - TS 10764 19 0 [dbu_evict] - TS 10765 19 0 [arc_prune] - TS 10766 19 0 [arc_reclaim] - TS 10767 19 0 [arc_user_evicts] - TS 10768 19 0 [l2arc_feed] - TS 10769 39 0 [z_unmount] - TS 10770 39 -20 [zvol] - TS 11011 39 -20 [z_null_iss] - TS 11012 39 -20 [z_null_int] - TS 11013 39 -20 [z_rd_iss] - TS 11014 39 -20 [z_rd_int_0] - TS 11022 38 -19 [z_wr_iss] - TS 11023 39 -20 [z_wr_iss_h] - TS 11024 39 -20 [z_wr_int_0] - TS 11032 39 -20 [z_wr_int_h] - TS 11033 39 -20 [z_fr_iss_0] - TS 11041 39 -20 [z_fr_int] - TS 11042 39 -20 [z_cl_iss] - TS 11043 39 -20 [z_cl_int] - TS 11044 39 -20 [z_ioctl_iss] - TS 11045 39 -20 [z_ioctl_int] - TS 11046 39 -20 [metaslab_group_] - TS 11050 19 0 [z_iput] - TS 11121 38 -19 [z_wr_iss] Note that under Linux the meaning of a processes priority is inverted with respect to illumos. High values on Linux indicate a _low_ priority while high value on illumos indicate a _high_ priority. In order to preserve the logical meaning of the minclsyspri and maxclsyspri macros when they are used by the illumos wrapper functions their values have been inverted. This way when changes are merged from upstream illumos we won't need to remember to invert the macro. It could also lead to confusion. This patch depends on https://github.com/zfsonlinux/spl/pull/466. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Ned Bass <[email protected]> Closes #3607
* Check for NULL in dmu_free_long_range_impl()Brian Behlendorf2015-07-281-1/+5
| | | | | | | | | | A NULL should never be passed as the dnode_t pointer to the function dmu_free_long_range_impl(). Regardless, because we have a reported occurrence of this let's add some error handling to catch this. Better to report a reasonable error to caller than panic the system. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3445
* Minor style cleanupBrian Behlendorf2015-07-231-10/+7
| | | | | | | | | Address minor differences in style between upstream and ZoL. This patch contains no functional differences and is solely designed to minimize the delta from upstream. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3533
* Remove double counting HDR_L2ONLY_SIZEBrian Behlendorf2015-07-231-3/+0
| | | | | | | | | | | Commit d962d5d didn't quite properly resolve the HDR_L2ONLY_SIZE accounting. Accounting is now performed only in the constructor and destructor which is a nice simplification. It should have been removed the from create and destroy functions. This brings up back in sync with upstream. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3533
* Add hdr_recl() reclaim callbackBrian Behlendorf2015-07-231-2/+18
| | | | | | | | | | | Originally removed because it wasn't required under Linux. However, there may still be some utility in signaling the arc reclaim thread under Linux via reclaim. This should already have happened by other means but it's not harmless and reduces another point of divergence with upstream. Signed-off-by: Brian Behlendorf <[email protected]> Issue #3533
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