Commit Graph

312 Commits

Author SHA1 Message Date
Ned Bass
417104bdd3 Use cached feature info in spa_add_feature_stats()
Avoid issuing I/O to the pool when retrieving feature flags information.
Trying to read the ZAPs from disk means that zpool clear would hang if
the pool is suspended and recovery would require a reboot. To keep the
feature stats resident in memory, we hang a cached nvlist off of the
spa.  It is built up from disk the first time spa_add_feature_stats() is
called, and refreshed thereafter using the cached feature reference
counts. spa_add_feature_stats() gets called at pool import time so we
can be sure the cached nvlist will be available if the pool is later
suspended.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3082
2015-03-05 14:11:10 -08:00
Brian Behlendorf
8c45def24a Linux 4.0 compat: bdi_setup_and_register()
The 'capabilities' argument which was passed to bdi_setup_and_register()
has been removed.  File systems should no longer pass BDI_CAP_MAP_COPY.
For our purposes this means there are now three different interfaces
which must be handled.  A zpl_bdi_setup_and_register() wrapper function
has been introduced to provide a single interface to the ZPL code.

* 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
* 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
* 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.

I've also taken this opportunity to remove HAVE_BDI because kernels
older then 2.6.32 are no longer supported.  All kernels newer than
this will have one of the above interfaces.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes #3128
2015-03-03 10:49:45 -08:00
Brian Behlendorf
4ec15b8dcf Use MUTEX_FSTRANS mutex type
There are regions in the ZFS code where it is desirable to be able
to be set PF_FSTRANS while a specific mutex is held.  The ZFS code
could be updated to set/clear this flag in all the correct places,
but this is undesirable for a few reasons.

1) It would require changes to a significant amount of the ZFS
   code.  This would complicate applying patches from upstream.

2) It would be easy to accidentally miss a critical region in
   the initial patch or to have an future change introduce a
   new one.

Both of these concerns can be addressed by using a new mutex type
which is responsible for managing PF_FSTRANS, support for which was
added to the SPL in commit zfsonlinux/spl@9099312 - Merge branch
'kmem-rework'.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #3050
Closes #3055
Closes #3062
Closes #3132
Closes #3142
Closes #2983
2015-03-03 10:46:40 -08:00
Jörg Thalheim
534759fad3 Linux 3.19 compat: file_inode was added
struct access f->f_dentry->d_inode was replaced by accessor function
file_inode(f)

Signed-off-by: Joerg Thalheim <joerg@higgsboson.tk>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3084
2015-02-10 11:24:51 -08:00
Chunwei Chen
53698a453d Read spl_hostid module parameter before gethostid()
If spl_hostid is set via module parameter, it's likely different from
gethostid(). Therefore, the userspace tool should read it first before
falling back to gethostid().

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3034
2015-02-04 16:44:53 -08:00
Brian Behlendorf
81971b137a Revert "SA spill block cache"
The SA spill_cache was originally introduced to avoid the need to
perform large kmem or vmem allocations.  Instead a small dedicated
cache of preallocated SA buffers was kept.

This solution was viable while the maximum block size was limited
to 128K.  But with the planned increase of the maximum block size
to 16M callers need to migrate to the zio_buf_alloc().  However,
they should be aware this interface is expected to change again
once the zio buffers are fully backed by scatter-gather lists.

Alternately, if the callers know these buffers will never be large
or be infrequently accessed they may kmem_alloc() or vmem_alloc()
the needed temporary space.

This change has the additional benegit of bringing the code back
inline with the upstream Illumos source.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:28 -08:00
Brian Behlendorf
285b29d959 Revert "Pre-allocate vdev I/O buffers"
Commit 86dd0fd added preallocated I/O buffers.  This is no longer
required after the recent kmem changes designed to make our memory
allocation interfaces behave more like those found on Illumos.  A
deadlock in this situation is no longer possible.

However, these allocations still have the potential to be expensive.
So a potential future optimization might be to perform then KM_NOSLEEP
so that they either succeed of fail quicky.  Either case is acceptable
here because we can safely abort the aggregation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:28 -08:00
Brian Behlendorf
60e1eda929 Add kmem_cache.h include to default context
As part of the spl kmem/vmem refactoring the kmem_cache_* functions
were split in to their own kmem_cache.h header.  This was done in
part so that kmem_* consumers would not be forced to include the
kmem_cache_* functions which mask several Linux SLAB/SLAB functions.

Because of this we now much explicitly include kmem_cache.h in the
zfs_context.h.  However, consumers such as Lustre which need access
to the KM_FLAGS but not the kmem_cache_* functions can now safely
just include kmem.h.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:28 -08:00
Brian Behlendorf
79c76d5b65 Change KM_PUSHPAGE -> KM_SLEEP
By marking DMU transaction processing contexts with PF_FSTRANS
we can revert the KM_PUSHPAGE -> KM_SLEEP changes.  This brings
us back in line with upstream.  In some cases this means simply
swapping the flags back.  For others fnvlist_alloc() was replaced
by nvlist_alloc(..., KM_PUSHPAGE) and must be reverted back to
fnvlist_alloc() which assumes KM_SLEEP.

The one place KM_PUSHPAGE is kept is when allocating ARC buffers
which allows us to dip in to reserved memory.  This is again the
same as upstream.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:26 -08:00
Brian Behlendorf
efcd79a883 Retire KM_NODEBUG
Callers of kmem_alloc() which passed the KM_NODEBUG flag to suppress
the large allocation warning have been replaced by vmem_alloc() as
appropriate.  The updated vmem_alloc() call will not print a warning
regardless of the size of the allocation.

A careful reader will notice that not all callers have been changed
to vmem_alloc().  Some have only had the KM_NODEBUG flag removed.
This was possible because the default warning threshold has been
increased to 32k.  This is desirable because it minimizes the need
for Linux specific code changes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:40:32 -08:00
Brian Behlendorf
92119cc259 Mark IO pipeline with PF_FSTRANS
In order to avoid deadlocking in the IO pipeline it is critical that
pageout be avoided during direct memory reclaim.  This ensures that
the pipeline threads can always make forward progress and never end
up blocking on a DMU transaction.  For this very reason Linux now
provides the PF_FSTRANS flag which may be set in the process context.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:28:05 -08:00
Ned Bass
49ee64e5e6 Remove duplicate typedefs from trace.h
Older versions of GCC (e.g. GCC 4.4.7 on RHEL6) do not allow duplicate
typedef declarations with the same type. The trace.h header contains
some typedefs to avoid 'unknown type' errors for C files that haven't
declared the type in question. But this causes build failures for C
files that have already declared the type. Newer versions of GCC (e.g.
v4.6) allow duplicate typedefs with the same type unless pedantic error
checking is in force. To support the older versions we need to remove
the duplicate typedefs.

Removal of the typedefs means we can't built tracepoints code using
those types unless the required headers have been included. To
facilitate this, all tracepoint event declarations have been moved out
of trace.h into separate headers. Each new header is explicitly included
from the C file that uses the events defined therein. The trace.h header
is still indirectly included form zfs_context.h and provides the
implementation of the dprintf(), dbgmsg(), and SET_ERROR() interfaces.
This makes those interfaces readily available throughout the code base.
The macros that redefine DTRACE_PROBE* to use Linux tracepoints are also
still provided by trace.h, so it is a prerequisite for the other
trace_*.h headers.

These new Linux implementation-specific headers do introduce a small
divergence from upstream ZFS in several core C files, but this should
not present a significant maintenance burden.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2953
2015-01-06 16:53:24 -08:00
Ned Bass
aaed7c408c Explicitly include SPL compat headers
Inclusion of SPL compatibility headers was moved out of the public
header sys/types.h to avoid conflicts with external packages.  Include a
few compatiblity headers explicitly to cope with that change.  Also,
sort some linux-specific inclusions alphabetically.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2898
2014-11-19 12:30:39 -05:00
Prakash Surya
0b39b9f96f Swap DTRACE_PROBE* with Linux tracepoints
This patch leverages Linux tracepoints from within the ZFS on Linux
code base. It also refactors the debug code to bring it back in sync
with Illumos.

The information exported via tracepoints can be used for a variety of
reasons (e.g. debugging, tuning, general exploration/understanding,
etc). It is advantageous to use Linux tracepoints as the mechanism to
export this kind of information (as opposed to something else) for a
number of reasons:

    * A number of external tools can make use of our tracepoints
      "automatically" (e.g. perf, systemtap)
    * Tracepoints are designed to be extremely cheap when disabled
    * It's one of the "accepted" ways to export this kind of
      information; many other kernel subsystems use tracepoints too.

Unfortunately, though, there are a few caveats as well:

    * Linux tracepoints appear to only be available to GPL licensed
      modules due to the way certain kernel functions are exported.
      Thus, to actually make use of the tracepoints introduced by this
      patch, one might have to patch and re-compile the kernel;
      exporting the necessary functions to non-GPL modules.

    * Prior to upstream kernel version v3.14-rc6-30-g66cc69e, Linux
      tracepoints are not available for unsigned kernel modules
      (tracepoints will get disabled due to the module's 'F' taint).
      Thus, one either has to sign the zfs kernel module prior to
      loading it, or use a kernel versioned v3.14-rc6-30-g66cc69e or
      newer.

Assuming the above two requirements are satisfied, lets look at an
example of how this patch can be used and what information it exposes
(all commands run as 'root'):

    # list all zfs tracepoints available

    $ ls /sys/kernel/debug/tracing/events/zfs
    enable              filter              zfs_arc__delete
    zfs_arc__evict      zfs_arc__hit        zfs_arc__miss
    zfs_l2arc__evict    zfs_l2arc__hit      zfs_l2arc__iodone
    zfs_l2arc__miss     zfs_l2arc__read     zfs_l2arc__write
    zfs_new_state__mfu  zfs_new_state__mru

    # enable all zfs tracepoints, clear the tracepoint ring buffer

    $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable
    $ echo 0 > /sys/kernel/debug/tracing/trace

    # import zpool called 'tank', inspect tracepoint data (each line was
    # truncated, they're too long for a commit message otherwise)

    $ zpool import tank
    $ cat /sys/kernel/debug/tracing/trace | head -n35
    # tracer: nop
    #
    # entries-in-buffer/entries-written: 1219/1219   #P:8
    #
    #                              _-----=> irqs-off
    #                             / _----=> need-resched
    #                            | / _---=> hardirq/softirq
    #                            || / _--=> preempt-depth
    #                            ||| /     delay
    #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
    #              | |       |   ||||       |         |
            lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss: hdr...
          z_rd_int/0-30156 [003] .... 91344.200611: zfs_new_state__mru...
            lt-zpool-30132 [003] .... 91344.201173: zfs_arc__miss: hdr...
          z_rd_int/1-30157 [003] .... 91344.201756: zfs_new_state__mru...
            lt-zpool-30132 [003] .... 91344.201795: zfs_arc__miss: hdr...
          z_rd_int/2-30158 [003] .... 91344.202099: zfs_new_state__mru...
            lt-zpool-30132 [003] .... 91344.202126: zfs_arc__hit: hdr ...
            lt-zpool-30132 [003] .... 91344.202130: zfs_arc__hit: hdr ...
            lt-zpool-30132 [003] .... 91344.202134: zfs_arc__hit: hdr ...
            lt-zpool-30132 [003] .... 91344.202146: zfs_arc__miss: hdr...
          z_rd_int/3-30159 [003] .... 91344.202457: zfs_new_state__mru...
            lt-zpool-30132 [003] .... 91344.202484: zfs_arc__miss: hdr...
          z_rd_int/4-30160 [003] .... 91344.202866: zfs_new_state__mru...
            lt-zpool-30132 [003] .... 91344.202891: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.203034: zfs_arc__miss: hdr...
          z_rd_iss/1-30149 [001] .... 91344.203749: zfs_new_state__mru...
            lt-zpool-30132 [001] .... 91344.203789: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.203878: zfs_arc__miss: hdr...
          z_rd_iss/3-30151 [001] .... 91344.204315: zfs_new_state__mru...
            lt-zpool-30132 [001] .... 91344.204332: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.204337: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.204352: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.204356: zfs_arc__hit: hdr ...
            lt-zpool-30132 [001] .... 91344.204360: zfs_arc__hit: hdr ...

To highlight the kind of detailed information that is being exported
using this infrastructure, I've taken the first tracepoint line from the
output above and reformatted it such that it fits in 80 columns:

    lt-zpool-30132 [003] .... 91344.200050: zfs_arc__miss:
        hdr {
            dva 0x1:0x40082
            birth 15491
            cksum0 0x163edbff3a
            flags 0x640
            datacnt 1
            type 1
            size 2048
            spa 3133524293419867460
            state_type 0
            access 0
            mru_hits 0
            mru_ghost_hits 0
            mfu_hits 0
            mfu_ghost_hits 0
            l2_hits 0
            refcount 1
        } bp {
            dva0 0x1:0x40082
            dva1 0x1:0x3000e5
            dva2 0x1:0x5a006e
            cksum 0x163edbff3a:0x75af30b3dd6:0x1499263ff5f2b:0x288bd118815e00
            lsize 2048
        } zb {
            objset 0
            object 0
            level -1
            blkid 0
        }

For the specific tracepoint shown here, 'zfs_arc__miss', data is
exported detailing the arc_buf_hdr_t (hdr), blkptr_t (bp), and
zbookmark_t (zb) that caused the ARC miss (down to the exact DVA!).
This kind of precise and detailed information can be extremely valuable
when trying to answer certain kinds of questions.

For anybody unfamiliar but looking to build on this, I found the XFS
source code along with the following three web links to be extremely
helpful:

    * http://lwn.net/Articles/379903/
    * http://lwn.net/Articles/381064/
    * http://lwn.net/Articles/383362/

I should also node the more "boring" aspects of this patch:

    * The ZFS_LINUX_COMPILE_IFELSE autoconf macro was modified to
       support a sixth paramter. This parameter is used to populate the
       contents of the new conftest.h file. If no sixth parameter is
       provided, conftest.h will be empty.

    * The ZFS_LINUX_TRY_COMPILE_HEADER autoconf macro was introduced.
      This macro is nearly identical to the ZFS_LINUX_TRY_COMPILE macro,
      except it has support for a fifth option that is then passed as
      the sixth parameter to ZFS_LINUX_COMPILE_IFELSE.

These autoconf changes were needed to test the availability of the Linux
tracepoint macros. Due to the odd nature of the Linux tracepoint macro
API, a separate ".h" must be created (the path and filename is used
internally by the kernel's define_trace.h file).

    * The HAVE_DECLARE_EVENT_CLASS autoconf macro was introduced. This
      is to determine if we can safely enable the Linux tracepoint
      functionality. We need to selectively disable the tracepoint code
      due to the kernel exporting certain functions as GPL only. Without
      this check, the build process will fail at link time.

In addition, the SET_ERROR macro was modified into a tracepoint as well.
To do this, the 'sdt.h' file was moved into the 'include/sys' directory
and now contains a userspace portion and a kernel space portion. The
dprintf and zfs_dbgmsg* interfaces are now implemented as tracepoint as
well.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2014-11-17 11:13:55 -08:00
Ned Bass
59ec819a0c Move a few internal ARC strucutres to arc_impl.h
Add a new file named arc_impl.h and move a few internal
ARC structure definitions into this file. This is
needed in order to allow the Linux tracepoint functions to grub
around in the internals of these structures.

Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2014-11-17 11:13:27 -08:00
Prakash Surya
fb42a49328 Illumos 5213 - panic in metaslab_init due to space_map_open returning ENXIO
5213 panic in metaslab_init due to space_map_open returning ENXIO
Reviewed by: Matthew Ahrens mahrens@delphix.com
Reviewed by: George Wilson george.wilson@delphix.com

References:
  https://www.illumos.org/issues/5213
  https://reviews.csiden.org/r/110

Porting notes:

For the Linux port, KM_SLEEP was replaced with KM_PUSHPAGE.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2745
2014-11-14 15:37:45 -08:00
Chris Wedgwood
b31d8ea77c Reduce buf/dbuf mutex contention
Due to evidence of contention both the buf_hash_table and the
dbuf_hash_table sizes have been increased from 256 to 8192.

This increase in hash table size adds approximating 0.5M to
our fixed memory footprint.  This relatively small increase
is not expected to cause problems even on low memory machines.
This footprint will also become dynamic when the persistent
L2ARC support is finalized.  In the meanwhile, this small
change significantly reduces contention for certain workloads.

Signed-off-by: Chris Wedgwood <cw@f00f.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes #1291
2014-11-14 14:59:21 -08:00
Alex Zhuravlev
0f69910833 Export symbols for ZIL interface
These symbols are needed by consumers (i.e. Lustre) who wish to
integrate with the ZIL.  In addition the zil_rollback_destroy()
prototype was removed because the implementation of this function
was removed long ago.

Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2892
2014-11-14 14:39:43 -08:00
Richard Yao
3cd33ffc3b Kernel header installation should respect --prefix
This is the upstream component of work that enables preliminary support
for building Gentoo's ZFS packaging on other Linux systems via Gentoo
Prefix.

Signed-off-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2641
2014-10-28 09:37:06 -07:00
Matthew Ahrens
9635861742 Illumos 5164-5165 - space map fixes
5164 space_map_max_blksz causes panic, does not work
5165 zdb fails assertion when run on pool with recently-enabled
     space map_histogram feature
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5164
  https://www.illumos.org/issues/5165
  https://github.com/illumos/illumos-gate/commit/b1be289

Porting Notes:

The metaslab_fragmentation() hunk was dropped from this patch
because it was already resolved by commit 8b0a084.

The comment modified in metaslab.c was updated to use the correct
variable name, space_map_blksz.  The upstream commit incorrectly
used space_map_blksize.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2697
2014-10-23 15:30:32 -07:00
Alex Reece
b02fe35d37 Illumos 4958 zdb trips assert on pools with ashift >= 0xe
4958 zdb trips assert on pools with ashift >= 0xe
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/4958
  https://github.com/illumos/illumos-gate/commit/2a104a5

Porting notes:

Keep the ZIO_FLAG_FASTWRITE define.  This is for a feature present
in Linux but not yet in *BSD.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2697
2014-10-23 15:30:32 -07:00
Brian Behlendorf
5f6d0b6f5a Handle block pointers with a corrupt logical size
The general strategy used by ZFS to verify that blocks are valid is
to checksum everything.  This has the advantage of being extremely
robust and generically applicable regardless of the contents of
the block.  If a blocks checksum is valid then its contents are
trusted by the higher layers.

This system works exceptionally well as long as bad data is never
written with a valid checksum.  If this does somehow occur due to
a software bug or a memory bit-flip on a non-ECC system it may
result in kernel panic.

One such place where this could occur is if somehow the logical
size stored in a block pointer exceeds the maximum block size.
This will result in an attempt to allocate a buffer greater than
the maximum block size causing a system panic.

To prevent this from happening the arc_read() function has been
updated to detect this specific case.  If a block pointer with an
invalid logical size is passed it will treat the block as if it
contained a checksum error.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2678
2014-10-23 09:20:52 -07:00
Matthew Ahrens
6c59307a3c Illumos 3693 - restore_object uses at least two transactions to restore an object
Restore_object should not use two transactions to restore an object:
  * one transaction is used for dmu_object_claim
  * another transaction is used to set compression, checksum and most
    importantly bonus data
  * furthermore dmu_object_reclaim internally uses multiple transactions
  * dmu_free_long_range frees chunks in separate transactions
  * dnode_reallocate is executed in a distinct transaction

The fact the dnode_allocate/dnode_reallocate are executed in one
transaction and bonus (re-)population is executed in a different
transaction may lead to violation of ZFS consistency assertions if the
transactions are assigned to different transaction groups.  Also, if
the first transaction group is successfully written to a permanent
storage, but the second transaction is lost, then an invalid dnode may
be created on the stable storage.

3693 restore_object uses at least two transactions to restore an object
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Andriy Gapon <andriy.gapon@hybridcluster.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Original authors: Matthew Ahrens and Andriy Gapon

References:
  https://www.illumos.org/issues/3693
  https://github.com/illumos/illumos-gate/commit/e77d42e

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2689
2014-10-21 15:26:50 -07:00
Brian Behlendorf
f0e324f25d Update utsname support
Modify the code to use the utsname() kernel function rather than
a global variable.  This results is cleaner more portable code
because utsname() is already provided by the kernel and can be
easily emulated in user space via uname(2).  This means that it
will behave consistently in both contexts.

This is also has the benefit that it allows the removal of a few
_KERNEL pre-processor conditions.  And it also is a pre-requisite
for a proper FUSE port because we need to provide a valid utsname.

Finally, it allows us to remove this functionality from the SPL
and all the related compatibility code.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2757
2014-10-17 14:58:57 -07:00
Brian Behlendorf
60bba62814 Update code to use misc_register()/misc_deregister()
When ZPIOS was originally written it was designed to use the
device_create() and device_destroy() functions.  Unfortunately,
these functions changed considerably over the years making them
difficult to rely on.

As it turns out a better choice would have been to use the
misc_register()/misc_deregister() functions.  This interface
for registering character devices has remained stable, is simple,
and provides everything we need.

Therefore the code has been reworked to use this interface.  The
higher level ZFS code has always depended on these same interfaces
so this is also as a step towards minimizing our kernel dependencies.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2757
2014-10-17 14:58:44 -07:00
Matthew Ahrens
e022864d19 Illumos 5176 - lock contention on godfather zio
5176 lock contention on godfather zio
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Bayard Bell <Bayard.Bell@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/5176
  https://github.com/illumos/illumos-gate/commit/6f834bc

Porting notes:

Under Linux max_ncpus is defined as num_possible_cpus().  This is
largest number of cpu ids which might be available during the life
time of the system boot.  This value can be larger than the number
of present cpus if CONFIG_HOTPLUG_CPU is defined.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2711
2014-10-07 11:24:24 -07:00
Richard Yao
83e9986f6e Implement -t option to zpool create for temporary pool names
Creating virtual machines that have their rootfs on ZFS on hosts that
have their rootfs on ZFS causes SPA namespace collisions when the
standard name rpool is used. The solution is either to give each guest
pool a name unique to the host, which is not always desireable, or boot
a VM environment containing an ISO image to install it, which is
cumbersome.

26b42f3f9d introduced `zpool import -t
...` to simplify situations where a host must access a guest's pool when
there is a SPA namespace conflict. We build upon that to introduce
`zpool import -t tname ...`. That allows us to create a pool whose
in-core name is tname, but whose on-disk name is the normal name
specified.

This simplifies the creation of machine images that use a rootfs on ZFS.
That benefits not only real world deployments, but also ZFSOnLinux
development by decreasing the time needed to perform rootfs on ZFS
experiments.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2417
2014-09-30 10:46:59 -07:00
Brian Behlendorf
aa0ac7caa4 Make user stack limit configurable
To aid in detecting and debugging stack overflow issues make the
user space stack limit configurable via a new ZFS_STACK_SIZE
environment variable.  The value assigned to ZFS_STACK_SIZE will
be used as the default stack size in bytes.

Because this is mainly useful as a debugging aid in conjunction
with ztest the stack limit is disabled by default.  See the ztest(1)
man page for additional details on using the ZFS_STACK_SIZE
environment variable.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #2743
Issue #2293
2014-09-30 10:46:55 -07:00
Alex Reece
acbad6ff67 Illumos 4753 - increase number of outstanding async writes when sync task is waiting
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
    https://www.illumos.org/issues/4753
    https://github.com/illumos/illumos-gate/commit/73527f4

Comments by Matt Ahrens from the issue tracker:
    When a sync task is waiting for a txg to complete, we should hurry
    it along by increasing the number of outstanding async writes
    (i.e. make vdev_queue_max_async_writes() return a larger number).
    Initially we might just have a tunable for "minimum async writes
    while a synctask is waiting" and set it to 3.

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2716
2014-09-23 13:50:55 -07:00
Tim Chase
223df0161f Implement fallocate FALLOC_FL_PUNCH_HOLE
Add support for the FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE mode of
fallocate(2).  Mimic the behavior of other native file systems such as
ext4 in cases where the file might be extended. If the offset is beyond
the end of the file, return success without changing the file. If the
extent of the punched hole would extend the file, only the existing tail
of the file is punched.

Add the zfs_zero_partial_page() function, modeled after update_page(),
to handle zeroing partial pages in a hole-punching operation.  It must
be used under a range lock for the requested region in order that the
ARC and page cache stay in sync.

Move the existing page cache truncation via truncate_setsize() into
zfs_freesp() for better source structure compatibility with upstream code.

Add page cache truncation to zfs_freesp() and zfs_free_range() to handle
hole punching.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #2619
2014-09-08 13:52:25 -07:00
Richard Yao
cd3939c5f0 Linux AIO Support
nfsd uses do_readv_writev() to implement fops->read and fops->write.
do_readv_writev() will attempt to read/write using fops->aio_read and
fops->aio_write, but it will fallback to fops->read and fops->write when
AIO is not available. However, the fallback will perform a call for each
individual data page. Since our default recordsize is 128KB, sequential
operations on NFS will generate 32 DMU transactions where only 1
transaction was needed. That was unnecessary overhead and we implement
fops->aio_read and fops->aio_write to eliminate it.

ZFS originated in OpenSolaris, where the AIO API is entirely implemented
in userland's libc by intelligently mapping them to VOP_WRITE, VOP_READ
and VOP_FSYNC.  Linux implements AIO inside the kernel itself. Linux
filesystems therefore must implement their own AIO logic and nearly all
of them implement fops->aio_write synchronously. Consequently, they do
not implement aio_fsync(). However, since the ZPL works by mapping
Linux's VFS calls to the functions implementing Illumos' VFS operations,
we instead implement AIO in the kernel by mapping the operations to the
VOP_READ, VOP_WRITE and VOP_FSYNC equivalents. We therefore implement
fops->aio_fsync.

One might be inclined to make our fops->aio_write implementation
synchronous to make software that expects this behavior safe. However,
there are several reasons not to do this:

1. Other platforms do not implement aio_write() synchronously and since
the majority of userland software using AIO should be cross platform,
expectations of synchronous behavior should not be a problem.

2. We would hurt the performance of programs that use POSIX interfaces
properly while simultaneously encouraging the creation of more
non-compliant software.

3. The broader community concluded that userland software should be
patched to properly use POSIX interfaces instead of implementing hacks
in filesystems to cater to broken software. This concept is best
described as the O_PONIES debate.

4. Making an asynchronous write synchronous is non sequitur.

Any software dependent on synchronous aio_write behavior will suffer
data loss on ZFSOnLinux in a kernel panic / system failure of at most
zfs_txg_timeout seconds, which by default is 5 seconds. This seems like
a reasonable consequence of using non-compliant software.

It should be noted that this is also a problem in the kernel itself
where nfsd does not pass O_SYNC on files opened with it and instead
relies on a open()/write()/close() to enforce synchronous behavior when
the flush is only guarenteed on last close.

Exporting any filesystem that does not implement AIO via NFS risks data
loss in the event of a kernel panic / system failure when something else
is also accessing the file. Exporting any file system that implements
AIO the way this patch does bears similar risk. However, it seems
reasonable to forgo crippling our AIO implementation in favor of
developing patches to fix this problem in Linux's nfsd for the reasons
stated earlier. In the interim, the risk will remain. Failing to
implement AIO will not change the problem that nfsd created, so there is
no reason for nfsd's mistake to block our implementation of AIO.

It also should be noted that `aio_cancel()` will always return
`AIO_NOTCANCELED` under this implementation. It is possible to implement
aio_cancel by deferring work to taskqs and use `kiocb_set_cancel_fn()`
to set a callback function for cancelling work sent to taskqs, but the
simpler approach is allowed by the specification:

```
Which operations are cancelable is implementation-defined.
```

http://pubs.opengroup.org/onlinepubs/009695399/functions/aio_cancel.html

The only programs on my system that are capable of using `aio_cancel()`
are QEMU, beecrypt and fio use it according to a recursive grep of my
system's `/usr/src/debug`. That suggests that `aio_cancel()` users are
rare. Implementing aio_cancel() is left to a future date when it is
clear that there are consumers that benefit from its implementation to
justify the work.

Lastly, it is important to know that handling of the iovec updates differs
between Illumos and Linux in the implementation of read/write. On Linux,
it is the VFS' responsibility whle on Illumos, it is the filesystem's
responsibility.  We take the intermediate solution of copying the iovec
so that the ZFS code can update it like on Solaris while leaving the
originals alone. This imposes some overhead. We could always revisit
this should profiling show that the allocations are a problem.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #223
Closes #2373
2014-09-05 15:11:43 -07:00
Isaac Huang
0426c16804 Fixed memory leaks in zevent handling
Some nvlist_t could be leaked in error handling paths.
Also make sure cb argument to zfs_zevent_post() cannnot
be NULL.

Signed-off-by: Isaac Huang <he.huang@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2158
2014-08-20 10:45:16 -07:00
Matthew Ahrens
bd089c5477 Illumos 4631 - zvol_get_stats triggering too many reads
4631 zvol_get_stats triggering too many reads

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4631
  https://github.com/illumos/illumos-gate/commit/bbfa8ea

Ported-by: Boris Protopopov <bprotopopov@hotmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2612
Closes #2480
2014-08-20 09:17:00 -07:00
George Wilson
f3a7f6610f Illumos 4976-4984 - metaslab improvements
4976 zfs should only avoid writing to a failing non-redundant top-level vdev
4978 ztest fails in get_metaslab_refcount()
4979 extend free space histogram to device and pool
4980 metaslabs should have a fragmentation metric
4981 remove fragmented ops vector from block allocator
4982 space_map object should proactively upgrade when feature is enabled
4983 need to collect metaslab information via mdb
4984 device selection should use fragmentation metric
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/4976
  https://www.illumos.org/issues/4978
  https://www.illumos.org/issues/4979
  https://www.illumos.org/issues/4980
  https://www.illumos.org/issues/4981
  https://www.illumos.org/issues/4982
  https://www.illumos.org/issues/4983
  https://www.illumos.org/issues/4984
  https://github.com/illumos/illumos-gate/commit/2e4c998

Notes:
    The "zdb -M" option has been re-tasked to display the new metaslab
    fragmentation metric and the new "zdb -I" option is used to control
    the maximum number of in-flight I/Os.

    The new fragmentation metric is derived from the space map histogram
    which has been rolled up to the vdev and pool level and is presented
    to the user via "zpool list".

    Add a number of module parameters related to the new metaslab weighting
    logic.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2595
2014-08-18 08:40:49 -07:00
Turbo Fredriksson
f67d709080 Create an 'overlay' property
Add a new 'overlay' property (default 'off') that controls whether the
filesystem should be mounted even if the mountpoint is busy or if it
should fail with a 'mountpoint not empty'.

Doing overlay mounts is the default mount behavior on Linux, but not
in ZFS. It have been decided that following the ZFS behavior should
be the default, but this overlay allows for site administrator to
override this decision on a per-dataset basis.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #2503
2014-08-15 13:39:19 -07:00
Richard Yao
194e56234a Include sys/taskq.h in linux/vfs_compat.h
We should have included sys/taskq.h directly because we use the taskq
code here, but we instead had files that included sys/taskq.h also
include sys/kmem.h, which happened to include sys/taskq.h. sys/kmem.h no
longer does this, so we must define the include as we should
have done in the first place.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2411
2014-08-14 12:38:17 -07:00
Alec Salazar
22a11a5b5a Replace __va_list with va_list
Most of the code base already uses va_list, which is specified by
iso-c. gcc/glibc provides 'typedef __gnuc_va_list va_list'. and
when not using gcc/glibc we can't expect to find __gnuc_va_list.

Signed-off-by: Alec Salazar <alec.j.salazar@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2588
2014-08-13 10:35:00 -07:00
Brian Behlendorf
0a50679ce9 Add zfs_iput_async() interface
Handle all iputs in zfs_purgedir() and zfs_inode_destroy()
asynchronously to prevent deadlocks.  When the iputs are allowed
to run synchronously in the destroy call path deadlocks between
xattr directory inodes and their parent file inodes are possible.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes #457
2014-08-11 16:11:43 -07:00
Brian Behlendorf
50b25b2187 Avoid dynamic allocation of 'search zio'
As part of commit e8b96c6 the search zio used by the
vdev_queue_io_to_issue() function was moved to the heap
to minimize stack usage.  Functionally this is fine, but
to maximize performance it's best to minimize the number
of dynamic allocations.

To avoid this allocation temporary space for the search
zio has been reserved in the vdev_queue structure.  All
access must be serialized through the vq_lock.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #2572
2014-08-11 08:44:54 -07:00
Matthew Ahrens
5dbd68a352 Illumos 4914 - zfs on-disk bookmark structure should be named *_phys_t
4914 zfs on-disk bookmark structure should be named *_phys_t

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Robert Mustacchi <rm@joyent.com>

References:
  https://www.illumos.org/issues/4914
  https://github.com/illumos/illumos-gate/commit/7802d7b

Porting notes:

There were a number of zfsonlinux-specific uses of zbookmark_t which
needed to be updated.  This should reduce the likelihood of further
problems like issue #2094 from occurring.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2558
2014-08-06 14:48:41 -07:00
Matthew Ahrens
fbeddd60b7 Illumos 4390 - I/O errors can corrupt space map when deleting fs/vol
4390 i/o errors when deleting filesystem/zvol can lead to space map corruption
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4390
  https://github.com/illumos/illumos-gate/commit/7fd05ac

Porting notes:

Previous stack-reduction efforts in traverse_visitb() caused a fair
number of un-mergable pieces of code.  This patch should reduce its
stack footprint a bit more.

The new local bptree_entry_phys_t in bptree_add() is dynamically-allocated
using kmem_zalloc() for the purpose of stack reduction.

The new global zfs_free_leak_on_eio has been defined as an integer
rather than a boolean_t as was the case with the related zfs_recover
global.  Also, zfs_free_leak_on_eio's definition has been inserted into
zfs_debug.c for consistency with the existing definition of zfs_recover.
Illumos placed it in spa_misc.c.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2545
2014-08-04 11:50:52 -07:00
Matthew Ahrens
9b67f60560 Illumos 4757, 4913
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4757
  https://www.illumos.org/issues/4913
  https://github.com/illumos/illumos-gate/commit/5d7b4d4

Porting notes:

For compatibility with the fastpath code the zio_done() function
needed to be updated.  Because embedded-data block pointers do
not require DVAs to be allocated the associated vdevs will not
be marked and therefore should not be unmarked.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2544
2014-08-01 14:28:05 -07:00
Matthew Ahrens
faf0f58c69 Illumos 3835 zfs need not store 2 copies of all metadata
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

Description from Matt Ahrens's bug report at Delphix:

    Add a new zfs property, "redundant_metadata" which can have values
    "all" or "most".  The default will be "all", which is the current
    behavior.  Setting to "most" will cause us to only store 1 copy of
    level-1 indirect blocks of user data files.

Additional notes:

    The new man page section for this property states

        "The exact behavior of which metadata blocks
         are stored redundantly may change in future releases."

    and:

        "When set to most, ZFS stores an extra copy of most types of
         metadata. This can improve performance of random writes,
         because less metadata must be written."

    The current implementation is as described above in Matt's blog.
    It is controlled by a new global integer
    "zfs_redundant_metadata_most_ditto_level", currently initialized
    to 2. When "redundant_metadata" is set to "most", only indirect
    blocks of the specified level and higher will have additional ditto
    blocks created.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2542
2014-07-31 09:49:34 -07:00
George Wilson
672692c7b7 Illumos 4754, 4755
4754 io issued to near-full luns even after setting noalloc threshold
4755 mg_alloc_failures is no longer needed

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4754
  https://www.illumos.org/issues/4755
  https://github.com/illumos/illumos-gate/commit/b6240e8

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2533
2014-07-30 10:30:05 -07:00
Matthew Ahrens
9bd274ddd8 Illumos #4374
4374 dn_free_ranges should use range_tree_t

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4374
  https://github.com/illumos/illumos-gate/commit/bf16b11

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2531
2014-07-30 09:20:35 -07:00
Matthew Ahrens
da536844d5 Illumos 4368, 4369.
4369 implement zfs bookmarks
4368 zfs send filesystems from readonly pools
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/4369
  https://www.illumos.org/issues/4368
  https://github.com/illumos/illumos-gate/commit/78f1710

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2530
2014-07-29 10:55:29 -07:00
Max Grossman
b0bc7a84d9 Illumos 4370, 4371
4370 avoid transmitting holes during zfs send
4371 DMU code clean up

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Garrett D'Amore <garrett@damore.org>a

References:
  https://www.illumos.org/issues/4370
  https://www.illumos.org/issues/4371
  https://github.com/illumos/illumos-gate/commit/43466aa

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2529
2014-07-28 14:29:58 -07:00
Matthew Ahrens
fa86b5dbb6 Illumos 4171, 4172
4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features

Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Approved by: Garrett D'Amore <garrett@damore.org>a

References:
  https://www.illumos.org/issues/4171
  https://www.illumos.org/issues/4172
  https://github.com/illumos/illumos-gate/commit/2acef22

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2528
2014-07-25 16:40:07 -07:00
Jan Engelhardt
aca19e063b Do not attempt access beyond the declared end of the dn_blkptr array
This loop in dmu_objset_write_ready():

	for (i = 0; i < dnp->dn_nblkptr; i++)
		bp->blk_fill += dnp->dn_blkptr[i].blk_fill;

invokes _undefined behavior_ for the (common) case of dn_nblkptr=3,
therefore, the compiler is free to do whatever it wants (such as
optimizing it away, or otherwise messing up your expections).

The fix is to be honest about the array size.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2511
Closes #2010
2014-07-22 09:55:37 -07:00
George Wilson
93cf20764a Illumos #4101, #4102, #4103, #4105, #4106
4101 metaslab_debug should allow for fine-grained control
4102 space_maps should store more information about themselves
4103 space map object blocksize should be increased
4105 removing a mirrored log device results in a leaked object
4106 asynchronously load metaslab
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <seb@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

Prior to this patch, space_maps were preferred solely based on the
amount of free space left in each. Unfortunately, this heuristic didn't
contain any information about the make-up of that free space, which
meant we could keep preferring and loading a highly fragmented space map
that wouldn't actually have enough contiguous space to satisfy the
allocation; then unloading that space_map and repeating the process.

This change modifies the space_map's to store additional information
about the contiguous space in the space_map, so that we can use this
information to make a better decision about which space_map to load.
This requires reallocating all space_map objects to increase their
bonus buffer size sizes enough to fit the new metadata.

The above feature can be enabled via a new feature flag introduced by
this change: com.delphix:spacemap_histogram

In addition to the above, this patch allows the space_map block size to
be increase. Currently the block size is set to be 4K in size, which has
certain implications including the following:

    * 4K sector devices will not see any compression benefit
    * large space_maps require more metadata on-disk
    * large space_maps require more time to load (typically random reads)

Now the space_map block size can adjust as needed up to the maximum size
set via the space_map_max_blksz variable.

A bug was fixed which resulted in potentially leaking an object when
removing a mirrored log device. The previous logic for vdev_remove() did
not deal with removing top-level vdevs that are interior vdevs (i.e.
mirror) correctly. The problem would occur when removing a mirrored log
device, and result in the DTL space map object being leaked; because
top-level vdevs don't have DTL space map objects associated with them.

References:
  https://www.illumos.org/issues/4101
  https://www.illumos.org/issues/4102
  https://www.illumos.org/issues/4103
  https://www.illumos.org/issues/4105
  https://www.illumos.org/issues/4106
  https://github.com/illumos/illumos-gate/commit/0713e23

Porting notes:

A handful of kmem_alloc() calls were converted to kmem_zalloc(). Also,
the KM_PUSHPAGE and TQ_PUSHPAGE flags were used as necessary.

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2488
2014-07-22 09:39:16 -07:00