Commit Graph

406 Commits

Author SHA1 Message Date
Brian Behlendorf
8780c53961 Update SAs when an inode is dirtied
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 <behlendorf1@llnl.gov>
Closes #764
Closes #1140
2012-12-14 12:18:54 -08:00
Ned Bass
7afcf5b1da Avoid ELOOP on auto-mounted snapshots
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 <behlendorf1@llnl.gov>
Closes #816
2012-12-13 08:57:11 -08:00
Brian Behlendorf
2ae1031962 Linux 3.7 compat, schedule_delayed_work()
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 <behlendorf1@llnl.gov>
Closes #1053
2012-12-12 10:47:05 -08:00
Richard Yao
e4d89e9cfc Switch KM_SLEEP to KM_PUSHPAGE
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
b8d06fca08 for additional details.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1138
2012-12-10 09:44:45 -08:00
Brian Behlendorf
53c7411919 Revert "Fix unlink/xattr deadlock"
This reverts commit b00131d43c which
is no longer needed due to e89260a1c8.

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 <behlendorf1@llnl.gov>
Closes #457
2012-12-05 13:41:30 -08:00
Brian Behlendorf
d3aa3ea96e Preserve inode mtime/ctime in .writepage()
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 <ryao@cs.stonybrook.edu>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #764
2012-12-05 13:00:25 -08:00
Brian Behlendorf
e89260a1c8 Directory xattr znodes hold a reference on their parent
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 <behlendorf1@llnl.gov>
Closes #671
2012-12-03 12:10:46 -08:00
Brian Behlendorf
c3275b56a1 Add load_nvlist() error handling
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 <behlendorf1@llnl.gov>
Closes #1120
2012-11-30 13:48:17 -08:00
Brian Behlendorf
004324ecc6 Disable page allocation warnings for super block
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 <behlendorf1@llnl.gov>
Issue #1101
2012-11-30 11:04:44 -08:00
Brian Behlendorf
f74a147c02 Fix NULL deref when zvol_alloc() fails
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 <lundman@lundman.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1109
2012-11-27 14:10:31 -08:00
George Wilson
32a9872bba Illumos #2671: zpool import should not fail if vdev ashift has increased
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Richard Lowe <richlowe@richlowe.net>

Refererces to Illumos issue:
      https://www.illumos.org/issues/2671

This patch has been slightly modified from the upstream Illumos
version.  In the upstream implementation a warning message is
logged to the console.  To prevent pointless console noise this
notification is now posted as a "ereport.fs.zfs.vdev.bad_ashift"
event.

The event indicates a non-optimial (but entirely safe) ashift
value was used to create the pool.  Depending on your workload
this may impact pool performance.  Unfortunately, the only way
to correct the issue is to recreate the pool with a new ashift.

NOTE: The unrelated fix to the comment in zpool_main.c appears
in the upstream commit and was preserved for consistnecy.

Ported-by: Cyril Plisko <cyril.plisko@mountall.com>
Reworked-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #955
2012-11-15 11:05:59 -08:00
Brian Behlendorf
4c837f0d93 Fix "allocating allocated segment" panic
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 <gunnar@beutner.name>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #541
2012-11-09 19:01:09 -08:00
Brian Behlendorf
e26ade5101 Fix zvol+btrfs hang
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 <cw@f00f.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #469
2012-11-09 12:24:51 -08:00
Brian Behlendorf
9dcb971983 Log I/Os longer than zio_delay_max (30s default)
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 <behlendorf1@llnl.gov>
Issue #930
2012-11-02 15:45:59 -07:00
Brian Behlendorf
e95853a331 Add txgs-<pool> kstat file
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 <behlendorf1@llnl.gov>
2012-11-02 15:45:56 -07:00
Brian Behlendorf
e8fd45a0f9 Add ddt_object_count() error handling
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 <behlendorf1@llnl.gov>
Closes #910
2012-10-29 08:57:45 -07:00
Brian Behlendorf
178e73b376 Revert "Don't ashift-align vdev read requests."
This reverts commit a5c20e2a0a which
accidentally introduced a regression for real 4k sector devices.
See issue #1065 for details.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1065
2012-10-24 15:25:33 -07:00
Brian Behlendorf
f21e5c6a17 Remove 'Resized bio's/dio' warning
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 <behlendorf1@llnl.gov>
2012-10-22 10:17:10 -07:00
Brian Behlendorf
c7dfc08629 Quote snapshot and mountpoint for .zfs automount
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 <behlendorf1@llnl.gov>
Closes #1027
2012-10-17 13:26:18 -07:00
Etienne Dechamps
5d7a86d114 Use the slog even with logbias=throughput.
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 <behlendorf1@llnl.gov>
Issue #1013
2012-10-17 08:56:46 -07:00
Etienne Dechamps
920dd524fb Add FASTWRITE algorithm for synchronous writes.
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 <behlendorf1@llnl.gov>
Issue #1013
2012-10-17 08:56:41 -07:00
Brian Behlendorf
a298dbde92 Condition variable usage, zp->r_{rd,wr}_cv
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 <behlendorf1@llnl.gov>
2012-10-15 16:02:03 -07:00
Brian Behlendorf
8c0712fd88 Condition variable usage, zilog->zl_cv_batch
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 <behlendorf1@llnl.gov>
2012-10-15 16:01:58 -07:00
Brian Behlendorf
99db9bfde7 Condition variable usage, zevent_cv
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 <behlendorf1@llnl.gov>
2012-10-15 16:01:54 -07:00
Massimo Maggi
6f53a6a229 Switch KM_SLEEP to KM_PUSHPAGE
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 <massimo@mmmm.it>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1038
2012-10-15 09:32:38 -07:00
Brian Behlendorf
c418410393 Limit zfs_vdev_aggregation_limit to SPA_MAXBLOCKSIZE
Prevent users from setting the zfs_vdev_aggregation_limit tuning
larger than SPA_MAXBLOCKSIZE.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #520
2012-10-15 09:28:43 -07:00
Yuxuan Shui
45ca2d91cb Return positive error number in zfsctl_shares_lookup.
Otherwise it will cause zpl_shares_lookup() to return a invalid
pointer when an error occurs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Closes #626 #885 #947 #977
2012-10-15 09:11:56 -07:00
Yuxuan Shui
558ef6d080 Linux 3.6 compat, iops->create()
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 <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #873
2012-10-14 14:42:25 -07:00
Yuxuan Shui
8f195a908f Linux 3.6 compat, iops->lookup()
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 <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #873
2012-10-14 13:06:54 -07:00
Yuxuan Shui
3c20361075 Linux 3.6 compat, sget()
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 <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #873
2012-10-14 13:06:48 -07:00
Yuxuan Shui
af26c4d4ab Linux 3.6 compat, sops->write_super() removed
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 <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #873
2012-10-14 11:33:56 -07:00
Etienne Dechamps
a5c20e2a0a Don't ashift-align vdev read requests.
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 <behlendorf1@llnl.gov>
Closes #1022
2012-10-12 12:01:56 -07:00
Richard Yao
b68503fb30 Remove vmem_size() consumers
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 <behlendorf1@llnl.gov>
Closes #831
2012-10-12 10:03:03 -07:00
Brian Behlendorf
87d98efe9e Fix zfs_txg_timeout module parameter
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 <behlendorf1@llnl.gov>
2012-10-11 15:07:09 -07:00
Richard Yao
7df05a4266 Fix zfs_write_limit_max integer size mismatch on 32-bit systems
Commit c409e4647f 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 <lundman@lundman.net>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #749
2012-10-11 11:09:25 -07:00
Cyril Plisko
15fd274973 Make zfs_immediate_write_sz a module paramater
zfs_immediate_write_sz variable is a tunable, but lacks proper
module_param() instrumentation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1032
2012-10-11 11:09:21 -07:00
Cyril Plisko
5b7e5b5ab9 txg is spelled as tgx in places
Term 'transaction group' is commonly abbreviated as txg in ZFS sources.
There are some places (Linux specific MODULE_PARAM_DESC() macros)
where it is incorrectly spelled as 'tgx'.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1030
2012-10-11 09:19:08 -07:00
Massimo Maggi
beb999445a Switch KM_SLEEP to KM_PUSHPAGE
Prevent snapshot_check to initiate I/O during memory allocation.

Signed-off-by: Massimo Maggi <massimo@mmmm.it>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1023
2012-10-08 10:19:05 -07:00
Brian Behlendorf
7bd04f2d7d Set default zvol elevator to noop
It doesn't make sense for a zvol to use the default system I/O
scheduler because it is a virtual device.  Therefore, we change
the default scheduler to 'noop' for zvols provided that the
elevator_change() function is available.  This interface has
been available since Linux 2.6.36 and appears in the RHEL 6.x
kernels.

We deliberately do not implement the method for older kernels
because it was racy and could result in system crashes.  It's
better to simply manually tune the scheduler for these kernels.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1017
2012-10-05 12:39:59 -07:00
Etienne Dechamps
089fa91bc5 Align DISCARD requests on zvols.
Currently, when processing DISCARD requests, zvol_discard() calls
dmu_free_long_range() with the precise offset and size of the request.

Unfortunately, this is not optimal for requests that are not aligned to
the zvol block boundaries. Indeed, in the case of an unaligned range,
dnode_free_range() will zero out the unaligned parts. Not only is this
useless since we are not freeing any space by doing so, it is also slow
because it translates to a read-modify-write operation.

This patch fixes the issue by rounding up the discard start offset to
the next volume block boundary, and rounding down the discard end
offset to the previous volume block boundary.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1010
2012-10-04 16:01:44 -07:00
Chris Dunlop
d75d6f294e Switch KM_SLEEP to KM_PUSHPAGE
This warning indicates the incorrect use of KM_SLEEP in a call
path which must use KM_PUSHPAGE to avoid deadlocking in direct
reclaim.  See commit b8d06fc for additional details.

  SPL: Fixing allocation for task txg_sync (6093) which
  used GFP flags 0x297bda7c with PF_NOFS set

Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1002
2012-10-04 10:44:09 -07:00
Matthew Ahrens
04434775b7 Illumos #3100: zvol rename fails with EBUSY when dirty.
illumos/illumos-gate@2e2c135528
Illumos changeset: 13780:6da32a929222

3100 zvol rename fails with EBUSY when dirty

Reviewed by: Christopher Siden <chris.siden@delphix.com>
Reviewed by: Adam H. Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Eric Schrock <eric.schrock@delphix.com>

Ported-by: Etienne Dechamps <etienne.dechamps@ovh.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #995
2012-10-03 13:59:02 -07:00
George Wilson
65947351e7 Illumos #3129, #3130
illumos/illumos-gate@d6afdce20f
Illumos changeset: 13794:7c5e0e746b2c

3129 'zpool reopen' restarts resilvers
3130 ztest failure: Assertion failed:
     0 == dmu_objset_destroy(name, B_FALSE) (0x0 == 0x10)

Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/3129
  https://www.illumos.org/issues/3130

Ported by: Etienne Dechamps <etienne.dechamps@ovh.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #994
2012-10-03 13:59:02 -07:00
Brian Behlendorf
6d1d976b2c Modify vdev_elevator_switch() to use elevator_change()
As of Linux 2.6.36 an elevator_change() interface was added.
This commit updates vdev_elevator_switch() to use this interface
when available, otherwise it falls back to the usermodehelper
method.

Original-patch-by: foobarz <sysop@xeon.(none)>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #906
2012-10-03 13:31:44 -07:00
Cyril Plisko
393b44c711 Implement .commit_metadata hook for NFS export
In order to implement synchronous NFS metadata semantics ZFS
needs to provide the .commit_metadata hook.  All it takes there
is to make sure changes are committed to ZIL.  Fortunately
zfs_fsync() does just that, so simply calling it from
zpl_commit_metadata() does the trick.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #969
2012-10-03 10:49:45 -07:00
Chris Wedgwood
23a61ccc1b zvol_probe should return NULL when the device isn't found.
Previously we returned ERR_PTR(-ENOENT) which the rest of the kernel
doesn't expect and as such we can oops.

Signed-off-by: Chris Wedgwood <cw@f00f.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #949
Closes #931
Closes #789
Closes #743
Closes #730
2012-10-03 10:39:12 -07:00
Bill Pijewski
37abac6d55 Illumos #2703: add mechanism to report ZFS send progress
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>

References:
  https://www.illumos.org/issues/2703

Ported by: Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-09-19 13:39:06 -07:00
Chris Siden
1bd201e70d Illumos #1948: zpool list should show more detailed pool info
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Albert Lee <trisk@nexenta.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References:
  https://www.illumos.org/issues/1948

Ported by:	Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #685
2012-09-19 13:39:05 -07:00
Brian Behlendorf
95fd8c9a7f Switch KM_SLEEP to KM_PUSHPAGE
This warning indicates the incorrect use of KM_SLEEP in a call
path which must use KM_PUSHPAGE to avoid deadlocking in direct
reclaim.  See commit b8d06fca08
for additional details.

  SPL: Fixing allocation for task txg_sync (6093) which
  used GFP flags 0x297bda7c with PF_NOFS set

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #973
2012-09-19 11:52:36 -07:00
Brian Behlendorf
ba367276d8 Switch KM_SLEEP to KM_PUSHPAGE
This warning indicates the incorrect use of KM_SLEEP in a call
path which must use KM_PUSHPAGE to avoid deadlocking in direct
reclaim.  See commit b8d06fca08
for additional details.

  SPL: Fixing allocation for task txg_sync (6093) which
  used GFP flags 0x297bda7c with PF_NOFS set

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #917
2012-09-17 11:22:23 -07:00