aboutsummaryrefslogtreecommitdiffstats
path: root/module
Commit message (Collapse)AuthorAgeFilesLines
* Illumos #3104: eliminate empty bpobjsMatthew Ahrens2013-01-086-11/+130
| | | | | | | | | | | | | | | | 3104 eliminate empty bpobjs Reviewed by: George Wilson <[email protected]> Reviewed by: Adam Leventhal <[email protected]> Reviewed by: Christopher Siden <[email protected]> Reviewed by: Garrett D'Amore <[email protected]> Approved by: Eric Schrock <[email protected]> References: illumos/illumos-gate@f17457368189aa911f774c38c1f21875a568bdca illumos changeset: 13782:8f78aae28a63 https://www.illumos.org/issues/3104 Ported-by: Brian Behlendorf <[email protected]>
* Fix __zio_execute() asynchronous dispatchBrian Behlendorf2013-01-081-9/+17
| | | | | | | | | | | | | | To save valuable stack all zio's were made asynchronous when in the tgx_sync_thread context or during pool initialization. See commit 2fac4c2 for the original patch and motivation. Unfortuantely, the changes to dsl_pool_sync_context() made by the feature flags broke this logic causing in __zio_execute() to dispatch itself infinitely when called during pool initialization. This commit refines the existing logic to specificly target only the two cases we care about. Signed-off-by: Brian Behlendorf <[email protected]>
* Illumos #3349: zpool upgrade -V bumps the on disk version numberGeorge Wilson2013-01-081-0/+8
| | | | | | | | | | | | | | | | 3349 zpool upgrade -V bumps the on disk version number, but leaves the in core version Reviewed by: Adam Leventhal <[email protected]> Reviewed by: Christopher Siden <[email protected]> Reviewed by: Matt Ahrens <[email protected]> Reviewed by: Richard Lowe <[email protected]> Approved by: Dan McDonald <[email protected]> References: illumos/illumos-gate@25345e466695fbe736faa53b8f3413d8e8f81981 https://www.illumos.org/issues/3349 Ported-by: Brian Behlendorf <[email protected]>
* Illumos #3086: unnecessarily setting DS_FLAG_INCONSISTENT on asyncMatthew Ahrens2013-01-087-113/+192
| | | | | | | | | | | | | | 3086 unnecessarily setting DS_FLAG_INCONSISTENT on async destroyed datasets Reviewed by: Christopher Siden <[email protected]> Approved by: Eric Schrock <[email protected]> References: illumos/illumos-gate@ce636f8b38e8c9ff484e880d9abb27251a882860 illumos changeset: 13776:cd512c80fd75 https://www.illumos.org/issues/3086 Ported-by: Brian Behlendorf <[email protected]>
* Illumos #2762: zpool command should have better support for feature flagsChristopher Siden2013-01-082-10/+20
| | | | | | | | | | | | | 2762 zpool command should have better support for feature flags Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: George Wilson <[email protected]> Approved by: Eric Schrock <[email protected]> References: illumos/illumos-gate@57221772c3fc05faba04bf48ddff45abf2bbf2bd https://www.illumos.org/issues/2762 Ported-by: Brian Behlendorf <[email protected]>
* Illumos #3090 and #3102George Wilson2013-01-084-51/+125
| | | | | | | | | | | | | | | | | | | 3090 vdev_reopen() during reguid causes vdev to be treated as corrupt 3102 vdev_uberblock_load() and vdev_validate() may read the wrong label Reviewed by: Matthew Ahrens <[email protected]> Reviewed by: Christopher Siden <[email protected]> Reviewed by: Garrett D'Amore <[email protected]> Approved by: Eric Schrock <[email protected]> References: illumos/illumos-gate@dfbb943217bf8ab22a1a9d2e9dca01d4da95ee0b illumos changeset: 13777:b1e53580146d https://www.illumos.org/issues/3090 https://www.illumos.org/issues/3102 Ported-by: Brian Behlendorf <[email protected]> Closes #939
* Illumos #2619 and #2747Christopher Siden2013-01-0830-365/+2454
| | | | | | | | | | | | | | | | | | | | | | 2619 asynchronous destruction of ZFS file systems 2747 SPA versioning with zfs feature flags Reviewed by: Matt Ahrens <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Richard Lowe <[email protected]> Reviewed by: Dan Kruchinin <[email protected]> Approved by: Eric Schrock <[email protected]> References: illumos/illumos-gate@53089ab7c84db6fb76c16ca50076c147cda11757 illumos/illumos-gate@ad135b5d644628e791c3188a6ecbd9c257961ef8 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 <[email protected]>
* Fix gcc array subscript above bounds warningNed Bass2013-01-071-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | In a debug build, certain GCC versions flag an array bounds warning in the below code from dnode_sync.c } else { int i; ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr); /* the blkptrs we are losing better be unallocated */ for (i = dn->dn_next_nblkptr[txgoff]; i < dnp->dn_nblkptr; i++) ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i])); This usage is in fact safe, since the ASSERT ensures the index does not exceed to maximum possible number of block pointers. However gcc can't determine that the assignment 'i = dn->dn_next_nblkptr[txgoff];' falls within the array bounds so it issues a warning. To avoid this, initialize i to zero to make gcc happy but skip the elements before dn->dn_next_nblkptr[txgoff] in the loop body. Since a dnode contains at most 3 block pointers this overhead should be negligible. Signed-off-by: Brian Behlendorf <[email protected]> Closes #950
* Use cv_wait_io() which will will account for iowaitMatt Johnston2013-01-071-1/+1
| | | | | | | Update zio_wait() to use cv_wait_io() to ensure the iowait time is properly accounted for. Signed-off-by: Brian Behlendorf <[email protected]>
* Revert part of "Log I/Os longer than zio_delay_max (30s default)"Matt Johnston2013-01-071-22/+10
| | | | | | | | | | | | | | | | | | | | | | | This reverts commit 9dcb97198338ba2d8764dd5604b278118612f74 which was originally introduced to debug occasional slow I/Os. These I/Os would complete eventually but were observed to take several 100 seconds. The root cause of this issue was the CFQ scheduler which can, under certain conditions, excessively delay an I/O from being issued to the device. This issue was mitigated somewhat by commit 84daaddedbfc9cf4bd1490d8a6f4b2967051e308 which ensures the I/O elevator gets changed even for DM style devices. This change isn't in any way harmful but it does conflict with a required change to properly account from I/O wait time. Because Linux does not export the io_schedule_timeout() function we must instead rely on io_schedule() via cv_wait_io(). The additional debugging information which was added to the delay event has been intentionally left in place. Signed-off-by: Brian Behlendorf <[email protected]>
* Fix zpool on zvol lock inversion deadlockBrian Behlendorf2012-12-201-0/+28
| | | | | | | | | | | | | | | | | | | | | | | In all but one case the spa_namespace_lock is taken before the bdev->bd_mutex lock. But Linux __blkdev_get() function calls fops->open() with the bdev->bd_mutex lock held and we must somehow still safely acquire the spa_namespace_lock. To avoid a potential lock inversion deadlock we preemptively try to take the spa_namespace_lock(). Normally it will not be contended and this is safe because spa_open_common() handles the case where the caller already holds the spa_namespace_lock. When it is contended we risk a lock inversion if we were to block waiting for the lock. Luckily, the __blkdev_get() function allows us to return -ERESTARTSYS which will result in bdev->bd_mutex being dropped, reacquired, and fops->open() being called again. This process can be repeated safely until both locks are acquired. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Jorgen Lundman <[email protected]> Closes #612
* Revert "Remove TSD zfs_fsyncer_key"Brian Behlendorf2012-12-203-1/+14
| | | | | | | | This reverts commit 31f2b5abdf95d8426d8bfd66ca7f62ec70215e3c back to the original code until the fsync(2) performance regression can be addressed. Signed-off-by: Brian Behlendorf <[email protected]>
* Remove TSD zfs_fsyncer_keyBrian Behlendorf2012-12-193-14/+1
| | | | | | | | | | | | | | | | | | | | It's my understanding that the zfs_fsyncer_key TSD was added as a performance omtimization to reduce contention on the zl_lock from zil_commit(). This issue manifested itself as very long (100+ms) fsync() system call times for fsync() heavy workloads. However, under Linux I'm not seeing the same contention that was originally described. Therefore, I'm removing this code in order to ween ourselves off any dependence on TSD. If the original performance issue reappears on Linux we can revisit fixing it without resorting to TSD. This just leaves one small ZFS TSD consumer. If it can be cleanly removed from the code we'll be able to shed the SPL TSD implementation entirely. Signed-off-by: Brian Behlendorf <[email protected]> Closes zfsonlinux/spl#174
* Set elevator for DM devices despite vdev_wholediskPrakash Surya2012-12-181-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current state of udev and devicer-mapper devices makes it difficult to construct a mapping of DM partitions and their underlying DM device. For example, with a /dev directory with the following contents: $ ls -d /dev/dm-* /dev/dm-0 /dev/dm-1 /dev/dm-2 /dev/dm-3 it is not immediately apparent if these are completely separate devices, or partitions and real devices intermixed. In contrast, SCSI devices would appear as so: $ ls -d /dev/sd* /dev/sda /dev/sda1 /dev/sdb /dev/sdb1 Here, one can immediately determine that there are two devices (sda and sdb), each containing a single partition. The lack of a predictable and consistent mapping from DM devices to DM device partitions makes it difficult for user space to process these devices the same way it does SCSI devices. As a result, the ZFS utilities do not partition DM devices, and instead set the "vdev_wholedisk" label to 0 and treat them as partitions. This has the side effect that, even if ZFS has sole ownership of the device, the IO scheduler will not be modified because it is treated as a partition. This change adds an exception for DM devices in vdev_elevator_switch, allowing the elevator to be modified even though the "vdev_wholedisk" property is not set. Signed-off-by: Prakash Surya <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1149
* Fix using zvol as slog deviceJorgen Lundman2012-12-182-13/+30
| | | | | | | | | | | | | | | During the original ZoL port the vdev_uses_zvols() function was disabled until it could be properly implemented. This prevented a zpool from use a zvol for its slog device. This patch implements that missing functionality by adding a zvol_is_zvol() function to zvol.c. Given the full path to a device it will lookup the device and verify its major number against the registered zvol major number for the system. If they match we know the device is a zvol. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1131
* Update SAs when an inode is dirtiedBrian Behlendorf2012-12-142-23/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | Revert the portion of commit d3aa3ea which always resulted in the SAs being update when an mmap()'ed file was closed. That change accidentally resulted in unexpected ctime updates which upset tools like git. That was always a horrible hack and I'm happy it will never make it in to a tagged release. The right fix is something I initially resisted doing because I was worried about the additional overhead. However, in hindsight the overhead isn't as bad as I feared. This patch implemented the sops->dirty_inode() callback which is unsurprisingly called when an inode is dirtied. We leverage this callback to keep the znode SAs strictly in sync with the inode. However, for now we're going to go slowly to avoid introducing any new unexpected issues by only updating the atime, mtime, and ctime. This will cover the callpath of most concern to us. ->filemap_page_mkwrite->file_update_time->update_time-> mark_inode_dirty_sync->__mark_inode_dirty->dirty_inode Signed-off-by: Brian Behlendorf <[email protected]> Closes #764 Closes #1140
* Avoid ELOOP on auto-mounted snapshotsNed Bass2012-12-131-0/+7
| | | | | | | | | | | | Ensure that the path member pointers are associated with the newly-mounted snapshot when zpl_snapdir_automount() returns. Otherwise the follow_automount() function may be called repeatedly, leading to an incorrect ELOOP error return. This problem was observed as a 'Too many levels of symbolic links' error from user-space commands accessing an unmounted snapshot in the .zfs/snapshot directory. Signed-off-by: Brian Behlendorf <[email protected]> Closes #816
* Linux 3.7 compat, schedule_delayed_work()Brian Behlendorf2012-12-121-11/+20
| | | | | | | | | | | | | | | | | | | | Linux kernel commit d8e794d accidentally broke the delayed work APIs for non-GPL callers. While the APIs to schedule a delayed work item are still available to all callers, it is no longer possible to initialize the delayed work item. I'm cautiously optimistic we could get the delayed_work_timer_fn exported for all callers in the upstream kernel. But frankly the compatibility code to use this kernel interface has always been problematic. Therefore, this patch abandons direct use the of the Linux kernel interface in favor of the new delayed taskq interface. It provides roughly the same functionality as delayed work queues but it's a stable interface under our control. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1053
* Switch KM_SLEEP to KM_PUSHPAGERichard Yao2012-12-101-1/+1
| | | | | | | | | | | When writes to zvols invoke ZIL, zfs_range_new_proxy() is called, which allocates memory using KM_SLEEP, triggering a warning. Switch to KM_PUSHPAGE to silence that warning. See commit b8d06fca089fae4680c3a552fc55c512bfb02202 for additional details. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1138
* Revert "Fix unlink/xattr deadlock"Brian Behlendorf2012-12-052-90/+55
| | | | | | | | | | | | | | | | | | This reverts commit b00131d43ca344d4b205a03ab3eb771a060e5087 which is no longer needed due to e89260a1c8851ce05ea04b23606ba438b271d890. This change forces all xattr znodes to hold a reference on their parent which ensures prune_icache() will never attempt to evict both the parent and child concurrently. This effectively prevents the deadlock condition from ever occuring. Therefore we can safely revert back to the upstream synchronous cleanup code. This is nice because it keeps our code base closer to upstream and resolves the performance issues introduced by the original deadlock fix. Signed-off-by: Brian Behlendorf <[email protected]> Closes #457
* Preserve inode mtime/ctime in .writepage()Brian Behlendorf2012-12-051-4/+32
| | | | | | | | | | | | | | | | | | | | | When updating a file via mmap()'ed I/O preserve the mtime/ctime which were updated when the page was made writable by the generic callback filemap_page_mkwrite(). But more importantly than preserving the exact time add the missing call to sa_bulk_update(). This ensures that the znode modifications are written to disk as part of the transaction. Without this the inode may mistaken rollback to the previous on-disk znode state. Additionally, for mmap()'ed znodes explicitly set the atime, mtime, and ctime on close using the up to date values in the inode. This is critical because writepage() may occur after close and on close we need to ensure the values are correct. Original-patch-by: Richard Yao <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #764
* Directory xattr znodes hold a reference on their parentBrian Behlendorf2012-12-033-29/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike normal file or directory znodes, an xattr znode is guaranteed to only have a single parent. Therefore, we can take a refernce on that parent if it is provided at create time and cache it. Additionally, we take care to cache it on any subsequent zfs_zaccess() where the parent is provided as an optimization. This allows us to avoid needing to do a zfs_zget() when setting up the SELinux security xattr in the create path. This is critical because a hash lookup on the directory will deadlock since it is locked. The zpl_xattr_security_init() call has also been moved up to the zpl layer to ensure TXs to create the required xattrs are performed after the create TX. Otherwise we run the risk of deadlocking on the open create TX. Ideally the security xattr should be fully constructed before the new inode is unlocked. However, doing so would require far more extensive changes to ZFS. This change may also have the benefitial side effect of ensuring xattr directory znodes are evicted from the cache before normal file or directory znodes due to the extra reference. Signed-off-by: Brian Behlendorf <[email protected]> Closes #671
* Add load_nvlist() error handlingBrian Behlendorf2012-11-301-1/+4
| | | | | | | | | | | Add the missing error handling to load_nvlist(). There's no good reason this needs to be fatal. All callers of load_nvlist() do correctly handle an error condition and it is preferable that an error be returned. This will allow 'zpool import -FX' to safely attempt to rollback through previous txgs looking for a good one. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1120
* Disable page allocation warnings for super blockBrian Behlendorf2012-11-301-1/+1
| | | | | | | | | | Due to the slightly increased size of the ZFS super block caused by 30315d2 there are now allocation warnings. The allocation size is still small (just over 8k) and super blocks are rarely allocated so we suppress the warning. Signed-off-by: Brian Behlendorf <[email protected]> Issue #1101
* Fix NULL deref when zvol_alloc() failsBrian Behlendorf2012-11-271-1/+1
| | | | | | | | | | If zvol_alloc() fails zv will be set to NULL and dereferenced in out_dmu_objset_disown. To avoid this entirely the zv->objset line is moved up in to the success block. Original-patch-by: Jorgen Lundman <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1109
* Illumos #2671: zpool import should not fail if vdev ashift has increasedGeorge Wilson2012-11-152-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reviewed by: Adam Leventhal <[email protected]> Reviewed by: Eric Schrock <[email protected]> Reviewed by: Richard Elling <[email protected]> Reviewed by: Gordon Ross <[email protected]> Reviewed by: Garrett D'Amore <[email protected]> Approved by: Richard Lowe <[email protected]> Refererces to Illumos issue: https://www.illumos.org/issues/2671 This patch has been slightly modified from the upstream Illumos version. In the upstream implementation a warning message is logged to the console. To prevent pointless console noise this notification is now posted as a "ereport.fs.zfs.vdev.bad_ashift" event. The event indicates a non-optimial (but entirely safe) ashift value was used to create the pool. Depending on your workload this may impact pool performance. Unfortunately, the only way to correct the issue is to recreate the pool with a new ashift. NOTE: The unrelated fix to the comment in zpool_main.c appears in the upstream commit and was preserved for consistnecy. Ported-by: Cyril Plisko <[email protected]> Reworked-by: Brian Behlendorf <[email protected]> Closes #955
* Fix "allocating allocated segment" panicBrian Behlendorf2012-11-091-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | Gunnar Beutner did all the hard work on this one by correctly identifying that this issue is a race between dmu_sync() and dbuf_dirty(). Now in all cases the caller is responsible for preventing this race by making sure the zfs_range_lock() is held when dirtying a buffer which may be referenced in a log record. The mmap case which relies on zfs_putpage() was not taking the range lock. This code was accidentally dropped when the function was rewritten for the Linux VFS. This patch adds the required range locking to zfs_putpage(). It also adds the missing ZFS_ENTER()/ZFS_EXIT() macros which aren't strictly required due to the VFS holding a reference. However, this makes the code more consistent with the upsteam code and there's no harm in being extra careful here. Original-patch-by: Gunnar Beutner <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #541
* Fix zvol+btrfs hangBrian Behlendorf2012-11-091-0/+77
| | | | | | | | | | | | | | | | | | | | | | | | When using a zvol to back a btrfs filesystem the btrfs mount would hang. This was due to the bio completion callback used in btrfs assuming that lower level drivers would never modify the bio->bi_io_vecs after they were submitted via bio_submit(). If they are modified btrfs will miscalculate which pages need to be unlocked resulting in a hang. It's worth mentioning that other file systems such as ext[234] and xfs work fine because they do not make the same assumption in the bio completion callback. The most straight forward way to fix the issue is to present the semantics expected by btrfs. This is done by cloning the bios attached to each request and then using the clones bvecs to perform the required accounting. The clones are freed after each read/write and the original unmodified bios are linked back in to the request. Signed-off-by: Chris Wedgwood <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #469
* Log I/Os longer than zio_delay_max (30s default)Brian Behlendorf2012-11-022-10/+26
| | | | | | | | | | | | | | | | | | | | | | | There have been reports of ZFS deadlocking due to what appears to be a lost IO. This patch addes some debugging to determine the exact state of the IO which neither 1) completed, 2) failed, or 3) timed out after zio_delay_max (30) seconds. This information will be logged using the ZFS FMA infrastructure as a 'delay' event and posted to the internal zevent log. By default the last 64 events will be kept in the log but the limit is configurable via the zfs_zevent_len_max module option. To dump the contents of the log use the 'zpool events -v' command and look for the resource.fs.zfs.delay event. It will include various information about the pool, vdev, and zio which may shed some light on the issue. In the context of this change the 120 second kernel blocked thread watchdog has been disabled for synchronous IOs. Signed-off-by: Brian Behlendorf <[email protected]> Issue #930
* Add txgs-<pool> kstat fileBrian Behlendorf2012-11-022-0/+190
| | | | | | | | | | | | | | | | | | | | Create a kstat file which contains useful statistics about the last N txgs processed. This can be helpful when analyzing pool performance. The new KSTAT_TYPE_TXG type was added for this purpose and it tracks the following statistics per-txg. txg - Unique txg number state - State (O)pen/(Q)uiescing/(S)yncing/(C)ommitted birth; - Creation time nread - Bytes read nwritten; - Bytes written reads - IOPs read writes - IOPs write open_time; - Length in nanoseconds the txg was open quiesce_time - Length in nanoseconds the txg was quiescing sync_time; - Length in nanoseconds the txg was syncing Signed-off-by: Brian Behlendorf <[email protected]>
* Add ddt_object_count() error handlingBrian Behlendorf2012-10-292-15/+22
| | | | | | | | | | | | | | | | | | | The interface for the ddt_zap_count() function assumes it can never fail. However, internally ddt_zap_count() is implemented with zap_count() which can potentially fail. Now because there was no way to return the error to the caller a VERIFY was used to ensure this case never happens. Unfortunately, it has been observed that pools can be damaged in such a way that zap_count() fails. The result is that the pool can not be imported without hitting the VERIFY and crashing the system. This patch reworks ddt_object_count() so the error can be safely caught and returned to the caller. This allows a pool which has be damaged in this way to be safely rewound for import. Signed-off-by: Brian Behlendorf <[email protected]> Closes #910
* Revert "Don't ashift-align vdev read requests."Brian Behlendorf2012-10-241-9/+3
| | | | | | | | | This reverts commit a5c20e2a0a9046c06d86615fbf51dc04f12bba14 which accidentally introduced a regression for real 4k sector devices. See issue #1065 for details. Signed-off-by: Brian Behlendorf <[email protected]> Issue #1065
* Remove 'Resized bio's/dio' warningBrian Behlendorf2012-10-221-1/+0
| | | | | | | | | | | | | The following warning was originally added to provide visibility in to how often a dio gets heavily fragmented in to over 16 bios. This can happen due to constraints imposed by the block device and may have a negitive impact on performance but is otherwise harmless. To prevent needless confusion and worry the message has been removed. kernel: WARNING: Resized bio's/dio to 32 Signed-off-by: Brian Behlendorf <[email protected]>
* Quote snapshot and mountpoint for .zfs automountBrian Behlendorf2012-10-171-2/+2
| | | | | | | | | | When automounting a snapshot in the .zfs/snapshot directory make sure to quote both the dataset name and the mount point. This ensures that if either component contains spaces, which are allowed, they get handled correctly. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1027
* Use the slog even with logbias=throughput.Etienne Dechamps2012-10-171-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the current code, logbias=throughput implies the following: 1) All synchronous writes are logged in indirect mode. 2) The slog is not used. (1) makes sense because it avoids writing the data twice, which is obviously a good thing when the user wants maximum pool throughput. (2), however, is a surprising decision. Considering all writes are indirect, the log record doesn't contain the actual data, only pointers to DMU blocks. As a result, log records written in logbias=throughput mode are quite small, and as such, it doesn't make any sense to write them to the main pool since slogs are usually optimized for small synchronous writes. In fact, the current behavior is actually harmful for performance, because log blocks and data blocks from dmu_sync() seldom have the same allocation size and as a result are usually allocated from different metaslabs. This means that if a spindle has to write both log blocks and DMU blocks (which is likely to happen under heavy load), it will have to seek between the two. Allocating the log blocks from the slog pool instead of the main pool avoids these unnecessary seeks. This commit makes ZFS use the slog on datasets with logbias=throughput. Real-life performance testing shows a 50% synchronous write performance increase with some large commit sizes, and no negative effect in other cases. Signed-off-by: Brian Behlendorf <[email protected]> Issue #1013
* Add FASTWRITE algorithm for synchronous writes.Etienne Dechamps2012-10-175-18/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, ZIL blocks are spread over vdevs using hint block pointers managed by the ZIL commit code and passed to metaslab_alloc(). Spreading log blocks accross vdevs is important for performance: indeed, using mutliple disks in parallel decreases the ZIL commit latency, which is the main performance metric for synchronous writes. However, the current implementation suffers from the following issues: 1) It would be best if the ZIL module was not aware of such low-level details. They should be handled by the ZIO and metaslab modules; 2) Because the hint block pointer is managed per log, simultaneous commits from multiple logs might use the same vdevs at the same time, which is inefficient; 3) Because dmu_write() does not honor the block pointer hint, indirect writes are not spread. The naive solution of rotating the metaslab rotor each time a block is allocated for the ZIL or dmu_sync() doesn't work in practice because the first ZIL block to be written is actually allocated during the previous commit. Consequently, when metaslab_alloc() decides the vdev for this block, it will do so while a bunch of other allocations are happening at the same time (from dmu_sync() and other ZILs). This means the vdev for this block is chosen more or less at random. When the next commit happens, there is a high chance (especially when the number of blocks per commit is slightly less than the number of the disks) that one disk will have to write two blocks (with a potential seek) while other disks are sitting idle, which defeats spreading and increases the commit latency. This commit introduces a new concept in the metaslab allocator: fastwrites. Basically, each top-level vdev maintains a counter indicating the number of synchronous writes (from dmu_sync() and the ZIL) which have been allocated but not yet completed. When the metaslab is called with the FASTWRITE flag, it will choose the vdev with the least amount of pending synchronous writes. If there are multiple vdevs with the same value, the first matching vdev (starting from the rotor) is used. Once metaslab_alloc() has decided which vdev the block is allocated to, it updates the fastwrite counter for this vdev. The rationale goes like this: when an allocation is done with FASTWRITE, it "reserves" the vdev until the data is written. Until then, all future allocations will naturally avoid this vdev, even after a full rotation of the rotor. As a result, pending synchronous writes at a given point in time will be nicely spread over all vdevs. This contrasts with the previous algorithm, which is based on the implicit assumption that blocks are written instantaneously after they're allocated. metaslab_fastwrite_mark() and metaslab_fastwrite_unmark() are used to manually increase or decrease fastwrite counters, respectively. They should be used with caution, as there is no per-BP tracking of fastwrite information, so leaks and "double-unmarks" are possible. There is, however, an assert in the vdev teardown code which will fire if the fastwrite counters are not zero when the pool is exported or the vdev removed. Note that as stated above, marking is also done implictly by metaslab_alloc(). ZIO also got a new FASTWRITE flag; when it is used, ZIO will pass it to the metaslab when allocating (assuming ZIO does the allocation, which is only true in the case of dmu_sync). This flag will also trigger an unmark when zio_done() fires. A side-effect of the new algorithm is that when a ZIL stops being used, its last block can stay in the pending state (allocated but not yet written) for a long time, polluting the fastwrite counters. To avoid that, I've implemented a somewhat crude but working solution which unmarks these pending blocks in zil_sync(), thus guaranteeing that linguering fastwrites will get pruned at each sync event. The best performance improvements are observed with pools using a large number of top-level vdevs and heavy synchronous write workflows (especially indirect writes and concurrent writes from multiple ZILs). Real-life testing shows a 200% to 300% performance increase with indirect writes and various commit sizes. Signed-off-by: Brian Behlendorf <[email protected]> Issue #1013
* Condition variable usage, zp->r_{rd,wr}_cvBrian Behlendorf2012-10-151-4/+5
| | | | | | | | The following incorrect usage of cv_broadcast() was caught by code inspection. The cv_broadcast() function must be called under the associated mutex to preventing racing with cv_wait(). Signed-off-by: Brian Behlendorf <[email protected]>
* Condition variable usage, zilog->zl_cv_batchBrian Behlendorf2012-10-151-1/+2
| | | | | | | | | The following incorrect usage of cv_signal and cv_broadcast() was caught by code inspection. The cv_signal and cv_broadcast() functions must be called under the associated mutex to preventing racing with cv_wait(). Signed-off-by: Brian Behlendorf <[email protected]>
* Condition variable usage, zevent_cvBrian Behlendorf2012-10-151-4/+7
| | | | | | | | The following incorrect usage of cv_broadcast() was caught by code inspection. The cv_broadcast() function must be called under the associated mutex to preventing racing with cv_wait(). Signed-off-by: Brian Behlendorf <[email protected]>
* Switch KM_SLEEP to KM_PUSHPAGEMassimo Maggi2012-10-151-2/+2
| | | | | | | | | | In this particular instance the allocation occurred in the context of sys_msync()->...->zpl_putpage() where we must be careful not to initiate additional I/O. Signed-off-by: Massimo Maggi <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1038
* Limit zfs_vdev_aggregation_limit to SPA_MAXBLOCKSIZEBrian Behlendorf2012-10-151-2/+2
| | | | | | | | Prevent users from setting the zfs_vdev_aggregation_limit tuning larger than SPA_MAXBLOCKSIZE. Signed-off-by: Brian Behlendorf <[email protected]> Closes #520
* Return positive error number in zfsctl_shares_lookup.Yuxuan Shui2012-10-151-1/+1
| | | | | | | | | Otherwise it will cause zpl_shares_lookup() to return a invalid pointer when an error occurs. Signed-off-by: Brian Behlendorf <[email protected]> Signed-off-by: Yuxuan Shui <[email protected]> Closes #626 #885 #947 #977
* Linux 3.6 compat, iops->create()Yuxuan Shui2012-10-141-0/+5
| | | | | | | | | | | | | As of Linux commit ebfc3b49a7ac25920cb5be5445f602e51d2ea559 the struct nameidata is no longer passed to iops->create. Instead only the result of (inamedata->flags & LOOKUP_EXCL) is passed. ZFS like almost all Linux fileystems never made use of this so only the prototype needs to be wrapped for compatibility. Signed-off-by: Yuxuan Shui <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #873
* Linux 3.6 compat, iops->lookup()Yuxuan Shui2012-10-142-0/+19
| | | | | | | | | | | | | As of Linux commit 00cd8dd3bf95f2cc8435b4cac01d9995635c6d0b the struct nameidata is no longer passed to iops->lookup. Instead only the inamedata->flags are passed. ZFS like almost all Linux fileystems never made use of this so only the prototype needs to be wrapped for compatibility. Signed-off-by: Yuxuan Shui <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #873
* Linux 3.6 compat, sget()Yuxuan Shui2012-10-141-2/+2
| | | | | | | | | | | | | As of Linux commit 9249e17fe094d853d1ef7475dd559a2cc7e23d42 the mount flags are now passed to sget() so they can be used when initializing a new superblock. ZFS never uses sget() in this fashion so we can simply pass a zero and add a zpl_sget() compatibility wrapper. Signed-off-by: Yuxuan Shui <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #873
* Linux 3.6 compat, sops->write_super() removedYuxuan Shui2012-10-141-1/+0
| | | | | | | | | | | | | | The .write_super callback was removed the the super_operations structure by Linux commit f0cd2dbb6cf387c11f87265462e370bb5469299e. All file systems are now expected to self manage writing any dirty state assoicated with their super block. ZFS never made use of this callback so it can simply be removed from the super_operations structure. Signed-off-by: Yuxuan Shui <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #873
* Don't ashift-align vdev read requests.Etienne Dechamps2012-10-121-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the size of read and write requests on vdevs is aligned according to the vdev's ashift, allocating a new ZIO buffer and padding if need be. This makes sense for write requests to prevent read/modify/write if the write happens to be smaller than the device's internal block size. For reads however, the rationale is less clear. It seems that the original code aligns reads because, on Solaris, device drivers will outright refuse unaligned requests. We don't have that issue on Linux. Indeed, Linux block devices are able to accept requests of any size, and take care of alignment issues themselves. As a result, there's no point in enforcing alignment for read requests on Linux. This is a nice optimization opportunity for two reasons: - We remove a memory allocation in a heavily-used code path; - The request gets aligned in the lowest layer possible, which shrinks the path that the additional, useless padding data has to travel. For example, when using 4k-sector drives that lie about their sector size, using 512b read requests instead of 4k means that there will be less data traveling down the ATA/SCSI interface, even though the drive actually reads 4k from the platter. The only exception is raidz, because raidz needs to read the whole allocated block for parity. This patch removes alignment enforcement for read requests, except on raidz. Note that we also remove an assertion that checks that we're aligning a top-level vdev I/O, because that's not the case anymore for repair writes that results from failed reads. Signed-off-by: Brian Behlendorf <[email protected]> Closes #1022
* Remove vmem_size() consumersRichard Yao2012-10-121-16/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | There are currently three vmem_size() consumers all of which are part of the ARC implemention. However, since the expected behavior of the Linux and Solaris virtual memory subsystems are so different the behavior in each of these instances needs to be reevaluated. * arc_evict_needed() - This is actually dead code. Arena support was never added to the SPL and zio_arena is always NULL. This support isn't needed so we simply remove this dead code. * arc_memory_throttle() - On Solaris where virtual memory constitutes almost all of the address space we can reasonably expect there to be a fairly large amount free. However, on Linux by default we only have about 100MB total and that's heavily used by the ARC. So the expectation on Linux is that this will usually be a small value. Therefore we remove the vmem_size() check for i386 systems because the expectation is that it will be less than the zfs_write_limit_max. * arc_init() - Here vmem_size() is used to initially size the ARC. Since the ARC is currently backed by the virtual address space it makes sense to use this as a limit on the ARC for 32-bit systems. This code can be removed when the ARC is backed by the page cache. Signed-off-by: Brian Behlendorf <[email protected]> Closes #831
* Fix zfs_txg_timeout module parameterBrian Behlendorf2012-10-112-6/+6
| | | | | | | | | | | | | | | | Allow the zfs_txg_timeout variable to be dynamically tuned at run time. By pulling it down out of the variable declaration it will be evaluted each time through the loop. The zfs_txg_timeout variable is now declared extern in a the common sys/txg.h header rather than locally in dsl_scan.c. This prevents potential type mismatches if the global variable needs to be used elsewhere. Move the module_param() code in to the same source file where zfs_txg_timeout is declared. This is the most logical location. Signed-off-by: Brian Behlendorf <[email protected]>
* Fix zfs_write_limit_max integer size mismatch on 32-bit systemsRichard Yao2012-10-111-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c409e4647f221ab724a0bd10c480ac95447203c3 introduced a number of module parameters. This required several types to be changed to accomidate the required module parameters Linux macros. Unfortunately, arc.c contained its own extern definition of the zfs_write_limit_max variable and its type was not updated to be consistent with its dsl_pool.c counterpart. If the variable had been properly marked extern in a common header, then gcc would have generated a warning and this would not have slipped through. The result of this was that the ARC unconditionally expected zfs_write_limit_max to be 64-bit. Unfortunately, the largest size integer module parameter that Linux supports is unsigned long, which varies in size depending on the host system's native word size. The effect was that on 32-bit systems, ARC incorrectly performed 64-bit operations on a 32-bit value by reading the neighboring 32 bits as the upper 32 bits of the 64-bit value. We correct that by changing the extern declaration to use the unsigned long type and move these extern definitions in to the common arc.h header. This should make ARC correctly treat zfs_write_limit_max as a 32-bit value on 32-bit systems. Reported-by: Jorgen Lundman <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #749
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 10:16:20 +0000