Commit Graph

1205 Commits

Author SHA1 Message Date
Tony Hutter
4eb0db42d3 Fix possible VDEV stats array overflow
Fix a possible VDEV statistics array overflow when ZIOs with
ZIO_PRIORITY_NOW complete.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4883
Closes #4917
2016-08-02 08:45:24 -07:00
Nikolay Borisov
ba2fe6affb Move assignment of i_blkbits field
Currently i_blkbits is always set to SPA_MINBLOCKSHIFT every time
zfs_inode_update_impl is called. Since this value never changes
move its assignment to at inode creation time.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4906
2016-07-29 15:34:12 -07:00
Nikolay Borisov
e334e828a6 Unify license of icp module with the rest of zfs
The newly added icp module uses a hardcoded value of CDDL for the license,
however in local development one might want to change that to something
else in order to facilitate compiling against lock debugging enabled kernel.
All modules of the zfs use the ZFS_META_LICNSE string which is replaced with
the value held in the META file. One can modify the value in the META file
once and then rerun the configure to have all modules' licenses changed.

Change the icp module license string to be ZFS_META_LICENSE so that it
falls under the same paradigm.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4905
2016-07-29 15:34:12 -07:00
heary-cao
9f3d1407dc Fix zfs_allow_log_destroy() NULL dereference
In zfs_ioc_log_history() function the tsd_set() function is called
with NULL which causes the zfs_allow_log_destroy() to be run.  In
this case the passed value will be NULL.  This is normally entirely
safe because strfree() maps directly to kfree() which may be passed
a NULL.  However, since alternate implementations of strfree() may
not handle this gracefully add a check for NULL.

Observed under an embedded Linux 2.6.32.41 kernel running the
automated testing while running the ZFS Test Suite.

Signed-off-by: caoxuewen <cao.xuewen@zte.com.cn>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4872
2016-07-29 15:34:12 -07:00
Chunwei Chen
3b86aeb295 Linux 4.8 compat: REQ_OP and bio_set_op_attrs()
New REQ_OP_* definitions have been introduced to separate the
WRITE, READ, and DISCARD operations from the flags.  This included
changing the encoding of bi_rw.  It places REQ_OP_* in high order
bits and other stuff in low order bits.  This encoding is done
through the new helper function bio_set_op_attrs.  For complete
details refer to:

https://github.com/torvalds/linux/commit/f215082
https://github.com/torvalds/linux/commit/4e1b2d5

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4892
Closes #4899
2016-07-29 14:48:19 -07:00
Brian Behlendorf
bbb1b6cea7 Linux 4.8 compat: submit_bio()
The rw argument has been removed from submit_bio/submit_bio_wait.
Callers are now expected to set bio->bi_rw instead of passing it
in.  See https://github.com/torvalds/linux/commit/4e49ea4a for
complete details.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4892
Issue #4899
2016-07-29 14:48:00 -07:00
Richard Yao
f26b4b3c8a txg visibility code should not execute under tc_open_lock
The memory allocation and locking in `spa_txg_history_*()` can
potentially block txg_hold_open for arbitrarily long periods of time.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4333
2016-07-27 14:11:13 -07:00
Brian Behlendorf
fcf64f45d9 Fix zdb crash with 4K-only devices
Here's the problem - on 4K native devices in userland on
Linux using O_DIRECT, buffers must be 4K aligned or I/O
will fail with EINVAL, causing zdb (and others) to coredump.
Since userland probably doesn't need optimized buffer caches,
we just force 4K alignment on everything.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #4479
2016-07-27 13:38:46 -07:00
Colin Ian King
bf18fd89f9 void integer overflow on computation of refquota_slack
DMU_MAX_ACCESS should be cast to a uint64_t otherwise the
multiplication of DMU_MAX_ACCESS with spa_asize_inflation will
be 32 bit and may lead to an overflow. Currently DMU_MAX_ACCESS
is 64 * 1024 * 1024, so spa_asize_inflation being 64 or more will
lead to an overflow.

Found by static analysis with CoverityScan 0.8.5

CID 150942 (#1 of 1): Unintentional integer overflow
  (OVERFLOW_BEFORE_WIDEN)
overflow_before_widen: Potentially overflowing expression
  67108864 * spa_asize_inflation with type int (32 bits, signed)
  is evaluated using 32-bit arithmetic, and then used in a context
  that expects an expression of type uint64_t (64 bits, unsigned).

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4889
2016-07-27 13:38:46 -07:00
Gvozden Neskovic
a64f903b06 Fixes for issues found with cppcheck tool
The patch fixes small number of errors/false positives reported by `cppcheck`,
static analysis tool for C/C++.

cppcheck 1.72

$ cppcheck . --force --quiet
[cmd/zfs/zfs_main.c:4444]: (error) Possible null pointer dereference: who_perm
[cmd/zfs/zfs_main.c:4445]: (error) Possible null pointer dereference: who_perm
[cmd/zfs/zfs_main.c:4446]: (error) Possible null pointer dereference: who_perm
[cmd/zpool/zpool_iter.c:317]: (error) Uninitialized variable: nvroot
[cmd/zpool/zpool_vdev.c:1526]: (error) Memory leak: child
[lib/libefi/rdwr_efi.c:1118]: (error) Memory leak: efi_label
[lib/libuutil/uu_misc.c:207]: (error) va_list 'args' was opened but not closed by va_end().
[lib/libzfs/libzfs_import.c:1554]: (error) Dangerous usage of 'diskname' (strncpy doesn't always null-terminate it).
[lib/libzfs/libzfs_sendrecv.c:3279]: (error) Dereferencing 'cp' after it is deallocated / released
[tests/zfs-tests/cmd/file_write/file_write.c:154]: (error) Possible null pointer dereference: operation
[tests/zfs-tests/cmd/randfree_file/randfree_file.c:90]: (error) Memory leak: buf
[cmd/zinject/zinject.c:1068]: (error) Uninitialized variable: dataset
[module/icp/io/sha2_mod.c:698]: (error) Uninitialized variable: blocks_per_int64

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1392
2016-07-27 13:31:22 -07:00
Tim Chase
25458cbef9 Limit the amount of dnode metadata in the ARC
Metadata-intensive workloads can cause the ARC to become permanently
filled with dnode_t objects as they're pinned by the VFS layer.
Subsequent data-intensive workloads may only benefit from about
25% of the potential ARC (arc_c_max - arc_meta_limit).

In order to help track metadata usage more precisely, the other_size
metadata arcstat has replaced with dbuf_size, dnode_size and bonus_size.

The new zfs_arc_dnode_limit tunable, which defaults to 10% of
zfs_arc_meta_limit, defines the minimum number of bytes which is desirable
to be consumed by dnodes.  Attempts to evict non-metadata will trigger
async prune tasks if the space used by dnodes exceeds this limit.

The new zfs_arc_dnode_reduce_percent tunable specifies the amount by
which the excess dnode space is attempted to be pruned as a percentage of
the amount by which zfs_arc_dnode_limit is being exceeded.  By default,
it tries to unpin 10% of the dnodes.

The problem of dnode metadata pinning was observed with the following
testing procedure (in this example, zfs_arc_max is set to 4GiB):

    - Create a large number of small files until arc_meta_used exceeds
      arc_meta_limit (3GiB with default tuning) and arc_prune
      starts increasing.

    - Create a 3GiB file with dd.  Observe arc_mata_used.  It will still
      be around 3GiB.

    - Repeatedly read the 3GiB file and observe arc_meta_limit as before.
      It will continue to stay around 3GiB.

With this modification, space for the 3GiB file is gradually made
available as subsequent demands on the ARC are made.  The previous behavior
can be restored by setting zfs_arc_dnode_limit to the same value as the
zfs_arc_meta_limit.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4345
Issue #4512
Issue #4773
Closes #4858
2016-07-25 15:26:38 -07:00
Tim Chase
e6603b7c1f Fix sync behavior for disk vdevs
Prior to b39c22b, which was first generally available in the 0.6.5
release as b39c22b, ZoL never actually submitted synchronous read or write
requests to the Linux block layer.  This means the vdev_disk_dio_is_sync()
function had always returned false and, therefore, the completion in
dio_request_t.dr_comp was never actually used.

In b39c22b, synchronous ZIO operations were translated to synchronous
BIO requests in vdev_disk_io_start().  The follow-on commits 5592404 and
aa159af fixed several problems introduced by b39c22b.  In particular,
5592404 introduced the new flag parameter "wait" to __vdev_disk_physio()
but under ZoL, since vdev_disk_physio() is never actually used, the wait
flag was always zero so the new code had no effect other than to cause
a bug in the use of the dio_request_t.dr_comp which was fixed by aa159af.

The original rationale for introducing synchronous operations in b39c22b
was to hurry certains requests through the BIO layer which would have
otherwise been subject to its unplug timer which would increase the
latency.  This behavior of the unplug timer, however, went away during the
transition of the plug/unplug system between kernels 2.6.32 and 2.6.39.

To handle the unplug timer behavior on 2.6.32-2.6.35 kernels the
BIO_RW_UNPLUG flag is used as a hint to suppress the plugging behavior.

For kernels 2.6.36-2.6.38, the REQ_UNPLUG macro will be available and
ise used for the same purpose.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4858
2016-07-25 14:24:47 -07:00
Brian Behlendorf
273ff9b5cc Fix uninitialized variable in avl_add()
Silence the following warning when compiling with gcc 5.4.0.
Specifically gcc (Ubuntu 5.4.0-6ubuntu1~16.04.1) 5.4.0 20160609.

module/avl/avl.c: In function ‘avl_add’:
module/avl/avl.c:647:2: warning: ‘where’ may be used uninitialized
    in this function [-Wmaybe-uninitialized]
  avl_insert(tree, new_node, where);

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-07-25 14:21:34 -07:00
Nikolay Borisov
2c6abf15ff Remove znode's z_uid/z_gid member
Remove duplicate z_uid/z_gid member which are also held in the
generic vfs inode struct. This is done by first removing the members
from struct znode and then using the KUID_TO_SUID/KGID_TO_SGID
macros to access the respective member from struct inode. In cases
where the uid/gids are being marshalled from/to disk, use the newly
introduced zfs_(uid|gid)_(read|write) functions to properly
save the uids rather than the internal kernel representation.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4685
Issue #227
2016-07-25 13:21:49 -07:00
Tom Caputi
77943bc1dc Fix for metaslab_fastwrite_unmark() assert failure
Currently there is an issue where metaslab_fastwrite_unmark() unmarks
fastwrites on vdev_t's that have never had fastwrites marked on them.
The 'fastwrite mark' is essentially a count of outstanding bytes that
will be written to a vdev and is used in syncing context. The problem
stems from the fact that the vdev_pending_fastwrite field is not being
transferred over when replacing a top-level vdev. As a result, the
metaslab is marked for fastwrite on the old vdev and unmarked on the
new one, which brings the fastwrite count below zero. This fix simply
assigns vdev_pending_fastwrite from the old vdev to the new one so
this count is not lost.

Signed-off-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4267
2016-07-25 13:21:43 -07:00
Tom Caputi
f4bc1bbe11 Fix for compilation error when using the kernel's CONFIG_LOCKDEP
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4329
2016-07-21 18:49:50 -07:00
Tom Caputi
0b04990a5d Illumos Crypto Port module added to enable native encryption in zfs
A port of the Illumos Crypto Framework to a Linux kernel module (found
in module/icp). This is needed to do the actual encryption work. We cannot
use the Linux kernel's built in crypto api because it is only exported to
GPL-licensed modules. Having the ICP also means the crypto code can run on
any of the other kernels under OpenZFS. I ended up porting over most of the
internals of the framework, which means that porting over other API calls (if
we need them) should be fairly easy. Specifically, I have ported over the API
functions related to encryption, digests, macs, and crypto templates. The ICP
is able to use assembly-accelerated encryption on amd64 machines and AES-NI
instructions on Intel chips that support it. There are place-holder
directories for similar assembly optimizations for other architectures
(although they have not been written).

Signed-off-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4329
2016-07-20 10:43:30 -07:00
Chunwei Chen
be88e733a6 Fix NULL pointer in zfs_preumount from 1d9b3bd
When zfs_domount fails zsb will be freed, and its caller
mount_nodev/get_sb_nodev will do deactivate_locked_super and calls into
zfs_preumount.

In order to make sure we don't touch any nonexistent stuff, we must make sure
s_fs_info is NULL in the fail path so zfs_preumount can easily check that.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4867
Issue #4854
2016-07-20 09:05:43 -07:00
Gvozden Neskovic
26a08b5ca9 RAIDZ parity kstat rework
Print table with speed of methods for each implementation.
Last line describes contents of [fastest] selection.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4860
2016-07-19 16:43:07 -07:00
Gvozden Neskovic
c9187d867f Fixes and enhancements of SIMD raidz parity
- Implementation lock replaced with atomic variable

- Trailing whitespace is removed from user specified parameter, to enhance
experience when using commands that add newline, e.g. `echo`

- raidz_test: remove dependency on `getrusage()` and RUSAGE_THREAD, Issue #4813

- silence `cppcheck` in vdev_raidz, partial solution of Issue #1392

- Minor fixes and cleanups

- Enable use of original parity methods in [fastest] configuration.
New opaque original ops structure, representing native methods, is added
to supported raidz methods. Original parity methods are executed if selected
implementation has NULL fn pointer.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4813
Issue #1392
2016-07-19 16:43:07 -07:00
Chunwei Chen
1d9b3bd8fb Wait iput_async before evict_inodes to prevent race
Wait for iput_async before entering evict_inodes in
generic_shutdown_super. The reason we must finish before
evict_inodes is when lazytime is on, or when zfs_purgedir calls
zfs_zget, iput would bump i_count from 0 to 1. This would race
with the i_count check in evict_inodes.  This means it could
destroy the inode while we are still using it.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4854
2016-07-19 09:23:58 -07:00
Tyler J. Stachecki
3d11ecbddd Prevent segfaults in SSE optimized Fletcher-4
In some cases, the compiler was not respecting the GNU aligned
attribute for stack variables in 35a76a0. This was resulting in
a segfault on CentOS 6.7 hosts using gcc 4.4.7-17.  This issue
was fixed in gcc 4.6.

To prevent this from occurring, use unaligned loads and stores
for all stack and global memory references in the SSE optimized
Fletcher-4 code.

Disable zimport testing against master where this flaw exists:

TEST_ZIMPORT_VERSIONS="installed"

Signed-off-by: Tyler J. Stachecki <stachecki.tyler@gmail.com>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4862
2016-07-19 09:03:44 -07:00
Roman Strashkin
1b87e0f532 Fix filesystem destroy with receive_resume_token
It is possible that the given DS may have hidden child (%recv)
datasets - "leftovers" resulting from the previously interrupted
'zfs receieve'.  Try to remove the hidden child (%recv) and after
that try to remove the target dataset.   If the hidden child
(%recv) does not exist the original error (EEXIST) will be returned.

Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4818
2016-07-15 15:34:46 -07:00
Tyler J. Stachecki
35a76a0366 Implementation of SSE optimized Fletcher-4
Builds off of 1eeb4562 (Implementation of AVX2 optimized Fletcher-4)
This commit adds another implementation of the Fletcher-4 algorithm.
It is automatically selected at module load if it benchmarks higher
than all other available implementations.

The module benchmark was also amended to analyze the performance of
the byteswap-ed version of Fletcher-4, as well as the non-byteswaped
version. The average performance of the two is used to select the
the fastest implementation available on the host system.

Adds a pair of fields to an existing zcommon module parameter:
-  zfs_fletcher_4_impl (str)
    "sse2"    - new SSE2 implementation if available
    "ssse3"   - new SSSE3 implementation if available

Signed-off-by: Tyler J. Stachecki <stachecki.tyler@gmail.com>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4789
2016-07-15 10:42:35 -07:00
Chris Dunlop
dfbc86309f Use native inode->i_nlink instead of znode->z_links
A mostly mechanical change, taking into account i_nlink is 32 bits vs ZFS's
64 bit on-disk link count.

We revert "xattr dir doesn't get purged during iput" (ddae16a) as this is a
more Linux-integrated fix for the same issue.

In addition, setting the initial link count on a new node has been changed
from setting one less than required in zfs_mknode() then incrementing to the
correct count in zfs_link_create() (which was somewhat bizarre in the first
place), to setting the correct count in zfs_mknode() and not incrementing it
in zfs_link_create(). This both means we no longer set the link count in
sa_bulk_update() twice (once for the initial incorrect count then again for
the correct count), as well as adhering to the Linux requirement of not
incrementing a zero link count without I_LINKABLE (see linux commit
f4e0c30c).

Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #4838
Issue #227
2016-07-14 16:25:34 -07:00
Chunwei Chen
02de3e3c5d Fix dbuf_stats_hash_table_data race
Dropping DBUF_HASH_MUTEX when walking the hash list is unsafe. The dbuf
can be freed at any time.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4846
2016-07-14 16:25:04 -07:00
Tim Chase
8887c7d778 Prevent null dereferences when accessing dbuf kstat
In arc_buf_info(), the arc_buf_t may have no header.  If not, don't try
to fetch the arc buffer stats and instead just zero them.

The null dereferences were observed while accessing the dbuf kstat with
awk on a system in which millions of small files were being created in
order to overflow the system's metadata limit.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #4837
2016-07-14 16:25:03 -07:00
Gvozden Neskovic
ae25d22235 Add RAID-Z routines for SSE2 instruction set, in x86_64 mode.
The patch covers low-end and older x86 CPUs.  Parity generation is
equivalent to SSSE3 implementation, but reconstruction is somewhat
slower.  Previous 'sse' implementation is renamed to 'ssse3' to
indicate highest instruction set used.

Benchmark results:
scalar_rec_p                    4    720476442
scalar_rec_q                    4    187462804
scalar_rec_r                    4    138996096
scalar_rec_pq                   4    140834951
scalar_rec_pr                   4    129332035
scalar_rec_qr                   4    81619194
scalar_rec_pqr                  4    53376668

sse2_rec_p                      4    2427757064
sse2_rec_q                      4    747120861
sse2_rec_r                      4    499871637
sse2_rec_pq                     4    522403710
sse2_rec_pr                     4    464632780
sse2_rec_qr                     4    319124434
sse2_rec_pqr                    4    205794190

ssse3_rec_p                     4    2519939444
ssse3_rec_q                     4    1003019289
ssse3_rec_r                     4    616428767
ssse3_rec_pq                    4    706326396
ssse3_rec_pr                    4    570493618
ssse3_rec_qr                    4    400185250
ssse3_rec_pqr                   4    377541245

original_rec_p                  4    691658568
original_rec_q                  4    195510948
original_rec_r                  4    26075538
original_rec_pq                 4    103087368
original_rec_pr                 4    15767058
original_rec_qr                 4    15513175
original_rec_pqr                4    10746357

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4783
2016-07-13 10:24:55 -07:00
Gvozden Neskovic
1bf3bf0e29 Fix handling of errors nvlist in zfs_ioc_recv_new()
zfs_ioc_recv_impl() is changed to always allocate the 'errors'
nvlist, its callers are responsible for freeing it.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4829
2016-07-13 10:20:08 -07:00
Peng
81edd3e834 Fix PANIC: metaslab_free_dva(): bad DVA X:Y:Z
The following scenario can result in garbage in the dn_spill field.
The db->db_blkptr must be set to NULL when DNODE_FLAG_SPILL_BLKPTR
is clear to ensure the dn_spill field is cleared.

Current txg = A.
* A new spill buffer is created. Its dbuf is initialized with
  db_blkptr = NULL and it's dirtied.

Current txg = B.
* The spill buffer is modified. It's marked as dirty in this txg.
* Additional changes make the spill buffer unnecessary because the
  xattr fits into the bonus buffer, so it's removed. The dbuf is
  undirtied in this txg, but it's still referenced and cannot be
  destroyed.

Current txg = C.
* Starts syncing of txg A
* dbuf_sync_leaf() is called for the spill buffer. Since db_blkptr
  is NULL, dbuf_check_blkptr() is called.
* The dbuf starts being written and it reaches the ready state
  (not done yet).
* A new change makes the spill buffer necessary again.
  sa_build_layouts() ends up calling dbuf_find() to locate the
  dbuf.  It finds the old dbuf because it has not been destroyed yet
  (it will be destroyed when the previous write is done and there
  are no more references). The old dbuf has db_blkptr != NULL.
* txg A write is complete and the dbuf released. However it's still
  referenced, so it's not destroyed.

Current txg = D.
* Starts syncing of txg B
* dbuf_sync_leaf() is called for the bonus buffer. Its contents are
  directly copied into the dnode, overwriting the blkptr area because,
  in txg B, the bonus buffer was big enough to hold the entire xattr.
* At this point, the db_blkptr of the spill buffer used in txg C
  gets corrupted.

Signed-off-by: Peng <peng.hse@xtaotech.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3937
2016-07-12 16:47:44 -07:00
Chunwei Chen
31b6111fd9 Kill zp->z_xattr_parent to prevent pinning
zp->z_xattr_parent will pin the parent. This will cause huge issue
when unlink a file with xattr. Because the unlinked file is pinned, it
will never get purged immediately. And because of that, the xattr
stuff will never be marked as unlinked. So the whole unlinked stuff
will stay there until shrink cache or umount.

This change partially reverts e89260a.  This is safe because only the
zp->z_xattr_parent optimization is removed, zpl_xattr_security_init()
is still called from the zpl outside the inode lock.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Issue #4359
Issue #3508
Issue #4413
Issue #4827
2016-07-12 14:18:10 -07:00
Chunwei Chen
ddae16a9cf xattr dir doesn't get purged during iput
We need to set inode->i_nlink to zero so iput will purge it. Without this, it
will get purged during shrink cache or umount, which would likely result in
deadlock due to zfs_zget waiting forever on its children which are in the
dispose_list of the same thread.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Issue #4359
Issue #3508
Issue #4413
Issue #4827
2016-07-12 14:04:30 -07:00
Chunwei Chen
6c2530647c fh_to_dentry should return ESTALE when generation mismatch
When generation mismatch, it usually means the file pointed by the file handle
was deleted. We should return ESTALE to indicate this. We return ENOENT in
zfs_vget since zpl_fh_to_dentry will convert it to ESTALE.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4828
2016-07-12 13:34:15 -07:00
Chunwei Chen
bffb68a2b8 Fix Large kmem_alloc in vdev_metaslab_init
This allocation can go way over 1MB, so we should use vmem_alloc
instead of kmem_alloc.

  Large kmem_alloc(1430784, 0x1000), please file an issue...
  Call Trace:
   [<ffffffffa0324aff>] ? spl_kmem_zalloc+0xef/0x160 [spl]
   [<ffffffffa17d0c8d>] ? vdev_metaslab_init+0x9d/0x1f0 [zfs]
   [<ffffffffa17d46d0>] ? vdev_load+0xc0/0xd0 [zfs]
   [<ffffffffa17d4643>] ? vdev_load+0x33/0xd0 [zfs]
   [<ffffffffa17c0004>] ? spa_load+0xfc4/0x1b60 [zfs]
   [<ffffffffa17c1838>] ? spa_tryimport+0x98/0x430 [zfs]
   [<ffffffffa17f28b1>] ? zfs_ioc_pool_tryimport+0x41/0x80 [zfs]
   [<ffffffffa17f5669>] ? zfsdev_ioctl+0x4a9/0x4e0 [zfs]
   [<ffffffff811bacdf>] ? do_vfs_ioctl+0x2cf/0x4b0
   [<ffffffff811baf41>] ? SyS_ioctl+0x81/0xa0

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4752
2016-07-12 13:34:15 -07:00
Chunwei Chen
7938c2aca7 Don't allow accessing XATTR via export handle
Allow accessing XATTR through export handle is a very bad idea. It
would allow user to write whatever they want in fields where they
otherwise could not.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4828
2016-07-12 13:34:14 -07:00
Chunwei Chen
061460dfe2 Fix get_zfs_sb race with concurrent umount
Certain ioctl operations will call get_zfs_sb, which will holds an active
count on sb without checking whether it's active or not. This will result
in use-after-free. We fix this by using atomic_inc_not_zero to make sure
we got an active sb.

P1                                          P2
---                                         ---
deactivate_locked_super(): s_active = 0
                                            zfs_sb_hold()
                                            ->get_zfs_sb(): s_active = 1
->zpl_kill_sb()
-->zpl_put_super()
--->zfs_umount()
---->zfs_sb_free(zsb)
                                            zfs_sb_rele(zsb)

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-07-12 13:34:14 -07:00
Gvozden Neskovic
590c9a0994 Allow building with CFLAGS="-O0"
If compiled with -O0, gcc doesn't do any stack frame coalescing
and -Wframe-larger-than=1024 is triggered in debug mode.
Starting with gcc 4.8, new opt level -Og is introduced for debugging, which
does not trigger this warning.

Fix bench zio size, using SPA_OLD_MAXBLOCKSHIFT

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4799
2016-07-11 16:53:02 -07:00
Brian Behlendorf
0dab2e84fc Vectorized fletcher_4 must be 128-bit aligned
The fletcher_4_native() and fletcher_4_byteswap() functions may only
safely use the vectorized implementations when the buffer is 128-bit
aligned.  This is because both the AVX2 and SSE implementations process
four 32-bit words per iterations.  Fallback to the scalar implementation
which only processes a single 32-bit word for unaligned buffers.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Issue #4330
2016-06-29 11:22:22 -07:00
Paul Dagnelie
d1d19c7854 OpenZFS 6876 - Stack corruption after importing a pool with a too-long name
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

Calling dsl_dataset_name on a dataset with a 256 byte buffer is asking
for trouble. We should check every dataset on import, using a 1024 byte
buffer and checking each time to see if the dataset's new name is longer
than 256 bytes.

OpenZFS-issue: https://www.illumos.org/issues/6876
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ca8674e
2016-06-28 13:47:04 -07:00
Igor Kozhukhov
eca7b76001 OpenZFS 6314 - buffer overflow in dsl_dataset_name
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6314
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d6160ee
2016-06-28 13:47:03 -07:00
Brian Behlendorf
43e52eddb1 Implement zfs_ioc_recv_new() for OpenZFS 2605
Adds ZFS_IOC_RECV_NEW for resumable streams and preserves the legacy
ZFS_IOC_RECV user/kernel interface.  The new interface supports all
stream options but is currently only used for resumable streams.
This way updated user space utilities will interoperate with older
kernel modules.

ZFS_IOC_RECV_NEW is modeled after the existing ZFS_IOC_SEND_NEW
handler.  Non-Linux OpenZFS platforms have opted to change the
legacy interface in an incompatible fashion instead of adding a
new ioctl.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-06-28 13:47:03 -07:00
Dan McDonald
8c62a0d0f3 OpenZFS 6562 - Refquota on receive doesn't account for overage
Authored by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6562
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/5f7a8e6
2016-06-28 13:47:03 -07:00
Dan McDonald
671c93546c OpenZFS 4986 - receiving replication stream fails if any snapshot exceeds refquota
Authored by: Dan McDonald <danmcd@omniti.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Gordon Ross <gordon.ross@nexenta.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/4986
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/5878fad
2016-06-28 13:47:03 -07:00
Eli Rosenthal
f8866f8ae3 OpenZFS 6738 - zfs send stream padding needs documentation
Authored by: Eli Rosenthal <eli.rosenthal@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6738
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c20404ff
2016-06-28 13:47:03 -07:00
Andrew Stormont
b607405fea OpenZFS 6536 - zfs send: want a way to disable setting of DRR_FLAG_FREERECORDS
Authored by: Andrew Stormont <astormont@racktopsystems.com>
Reviewed by: Anil Vijarnia <avijarnia@racktopsystems.com>
Reviewed by: Kim Shrier <kshrier@racktopsystems.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6536
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/880094b
2016-06-28 13:47:03 -07:00
Paul Dagnelie
e6d3a843d6 OpenZFS 6393 - zfs receive a full send as a clone
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6394
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/68ecb2e
2016-06-28 13:47:03 -07:00
Matthew Ahrens
47dfff3b86 OpenZFS 2605, 6980, 6902
2605 want to resume interrupted zfs send
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Reviewed by: Arne Jansen <sensille@gmx.net>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported-by: kernelOfTruth <kerneloftruth@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/2605
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/9c3fd12

6980 6902 causes zfs send to break due to 32-bit/64-bit struct mismatch
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6980
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ea4a67f

Porting notes:
- All rsend and snapshop tests enabled and updated for Linux.
- Fix misuse of input argument in traverse_visitbp().
- Fix ISO C90 warnings and errors.
- Fix gcc 'missing braces around initializer' in
  'struct send_thread_arg to_arg =' warning.
- Replace 4 argument fletcher_4_native() with 3 argument version,
  this change was made in OpenZFS 4185 which has not been ported.
- Part of the sections for 'zfs receive' and 'zfs send' was
  rewritten and reordered to approximate upstream.
- Fix mktree xattr creation, 'user.' prefix required.
- Minor fixes to newly enabled test cases
- Long holds for volumes allowed during receive for minor registration.
2016-06-28 13:47:02 -07:00
Ned Bass
50c957f702 Implement large_dnode pool feature
Justification
-------------

This feature adds support for variable length dnodes. Our motivation is
to eliminate the overhead associated with using spill blocks.  Spill
blocks are used to store system attribute data (i.e. file metadata) that
does not fit in the dnode's bonus buffer. By allowing a larger bonus
buffer area the use of a spill block can be avoided.  Spill blocks
potentially incur an additional read I/O for every dnode in a dnode
block. As a worst case example, reading 32 dnodes from a 16k dnode block
and all of the spill blocks could issue 33 separate reads. Now suppose
those dnodes have size 1024 and therefore don't need spill blocks.  Then
the worst case number of blocks read is reduced to from 33 to two--one
per dnode block. In practice spill blocks may tend to be co-located on
disk with the dnode blocks so the reduction in I/O would not be this
drastic. In a badly fragmented pool, however, the improvement could be
significant.

ZFS-on-Linux systems that make heavy use of extended attributes would
benefit from this feature. In particular, ZFS-on-Linux supports the
xattr=sa dataset property which allows file extended attribute data
to be stored in the dnode bonus buffer as an alternative to the
traditional directory-based format. Workloads such as SELinux and the
Lustre distributed filesystem often store enough xattr data to force
spill bocks when xattr=sa is in effect. Large dnodes may therefore
provide a performance benefit to such systems.

Other use cases that may benefit from this feature include files with
large ACLs and symbolic links with long target names. Furthermore,
this feature may be desirable on other platforms in case future
applications or features are developed that could make use of a
larger bonus buffer area.

Implementation
--------------

The size of a dnode may be a multiple of 512 bytes up to the size of
a dnode block (currently 16384 bytes). A dn_extra_slots field was
added to the current on-disk dnode_phys_t structure to describe the
size of the physical dnode on disk. The 8 bits for this field were
taken from the zero filled dn_pad2 field. The field represents how
many "extra" dnode_phys_t slots a dnode consumes in its dnode block.
This convention results in a value of 0 for 512 byte dnodes which
preserves on-disk format compatibility with older software.

Similarly, the in-memory dnode_t structure has a new dn_num_slots field
to represent the total number of dnode_phys_t slots consumed on disk.
Thus dn->dn_num_slots is 1 greater than the corresponding
dnp->dn_extra_slots. This difference in convention was adopted
because, unlike on-disk structures, backward compatibility is not a
concern for in-memory objects, so we used a more natural way to
represent size for a dnode_t.

The default size for newly created dnodes is determined by the value of
a new "dnodesize" dataset property. By default the property is set to
"legacy" which is compatible with older software. Setting the property
to "auto" will allow the filesystem to choose the most suitable dnode
size. Currently this just sets the default dnode size to 1k, but future
code improvements could dynamically choose a size based on observed
workload patterns. Dnodes of varying sizes can coexist within the same
dataset and even within the same dnode block. For example, to enable
automatically-sized dnodes, run

 # zfs set dnodesize=auto tank/fish

The user can also specify literal values for the dnodesize property.
These are currently limited to powers of two from 1k to 16k. The
power-of-2 limitation is only for simplicity of the user interface.
Internally the implementation can handle any multiple of 512 up to 16k,
and consumers of the DMU API can specify any legal dnode value.

The size of a new dnode is determined at object allocation time and
stored as a new field in the znode in-memory structure. New DMU
interfaces are added to allow the consumer to specify the dnode size
that a newly allocated object should use. Existing interfaces are
unchanged to avoid having to update every call site and to preserve
compatibility with external consumers such as Lustre. The new
interfaces names are given below. The versions of these functions that
don't take a dnodesize parameter now just call the _dnsize() versions
with a dnodesize of 0, which means use the legacy dnode size.

New DMU interfaces:
  dmu_object_alloc_dnsize()
  dmu_object_claim_dnsize()
  dmu_object_reclaim_dnsize()

New ZAP interfaces:
  zap_create_dnsize()
  zap_create_norm_dnsize()
  zap_create_flags_dnsize()
  zap_create_claim_norm_dnsize()
  zap_create_link_dnsize()

The constant DN_MAX_BONUSLEN is renamed to DN_OLD_MAX_BONUSLEN. The
spa_maxdnodesize() function should be used to determine the maximum
bonus length for a pool.

These are a few noteworthy changes to key functions:

* The prototype for dnode_hold_impl() now takes a "slots" parameter.
  When the DNODE_MUST_BE_FREE flag is set, this parameter is used to
  ensure the hole at the specified object offset is large enough to
  hold the dnode being created. The slots parameter is also used
  to ensure a dnode does not span multiple dnode blocks. In both of
  these cases, if a failure occurs, ENOSPC is returned. Keep in mind,
  these failure cases are only possible when using DNODE_MUST_BE_FREE.

  If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
  dnode_hold_impl() will check if the requested dnode is already
  consumed as an extra dnode slot by an large dnode, in which case
  it returns ENOENT.

* The function dmu_object_alloc() advances to the next dnode block
  if dnode_hold_impl() returns an error for a requested object.
  This is because the beginning of the next dnode block is the only
  location it can safely assume to either be a hole or a valid
  starting point for a dnode.

* dnode_next_offset_level() and other functions that iterate
  through dnode blocks may no longer use a simple array indexing
  scheme. These now use the current dnode's dn_num_slots field to
  advance to the next dnode in the block. This is to ensure we
  properly skip the current dnode's bonus area and don't interpret it
  as a valid dnode.

zdb
---
The zdb command was updated to display a dnode's size under the
"dnsize" column when the object is dumped.

For ZIL create log records, zdb will now display the slot count for
the object.

ztest
-----
Ztest chooses a random dnodesize for every newly created object. The
random distribution is more heavily weighted toward small dnodes to
better simulate real-world datasets.

Unused bonus buffer space is filled with non-zero values computed from
the object number, dataset id, offset, and generation number.  This
helps ensure that the dnode traversal code properly skips the interior
regions of large dnodes, and that these interior regions are not
overwritten by data belonging to other dnodes. A new test visits each
object in a dataset. It verifies that the actual dnode size matches what
was stored in the ztest block tag when it was created. It also verifies
that the unused bonus buffer space is filled with the expected data
patterns.

ZFS Test Suite
--------------
Added six new large dnode-specific tests, and integrated the dnodesize
property into existing tests for zfs allow and send/recv.

Send/Receive
------------
ZFS send streams for datasets containing large dnodes cannot be received
on pools that don't support the large_dnode feature. A send stream with
large dnodes sets a DMU_BACKUP_FEATURE_LARGE_DNODE flag which will be
unrecognized by an incompatible receiving pool so that the zfs receive
will fail gracefully.

While not implemented here, it may be possible to generate a
backward-compatible send stream from a dataset containing large
dnodes. The implementation may be tricky, however, because the send
object record for a large dnode would need to be resized to a 512
byte dnode, possibly kicking in a spill block in the process. This
means we would need to construct a new SA layout and possibly
register it in the SA layout object. The SA layout is normally just
sent as an ordinary object record. But if we are constructing new
layouts while generating the send stream we'd have to build the SA
layout object dynamically and send it at the end of the stream.

For sending and receiving between pools that do support large dnodes,
the drr_object send record type is extended with a new field to store
the dnode slot count. This field was repurposed from unused padding
in the structure.

ZIL Replay
----------
The dnode slot count is stored in the uppermost 8 bits of the lr_foid
field. The bits were unused as the object id is currently capped at
48 bits.

Resizing Dnodes
---------------
It should be possible to resize a dnode when it is dirtied if the
current dnodesize dataset property differs from the dnode's size, but
this functionality is not currently implemented. Clearly a dnode can
only grow if there are sufficient contiguous unused slots in the
dnode block, but it should always be possible to shrink a dnode.
Growing dnodes may be useful to reduce fragmentation in a pool with
many spill blocks in use. Shrinking dnodes may be useful to allow
sending a dataset to a pool that doesn't support the large_dnode
feature.

Feature Reference Counting
--------------------------
The reference count for the large_dnode pool feature tracks the
number of datasets that have ever contained a dnode of size larger
than 512 bytes. The first time a large dnode is created in a dataset
the dataset is converted to an extensible dataset. This is a one-way
operation and the only way to decrement the feature count is to
destroy the dataset, even if the dataset no longer contains any large
dnodes. The complexity of reference counting on a per-dnode basis was
too high, so we chose to track it on a per-dataset basis similarly to
the large_block feature.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3542
2016-06-24 13:13:21 -07:00
Ned Bass
68cbd56e18 Backfill metadnode more intelligently
Only attempt to backfill lower metadnode object numbers if at least
4096 objects have been freed since the last rescan, and at most once
per transaction group. This avoids a pathology in dmu_object_alloc()
that caused O(N^2) behavior for create-heavy workloads and
substantially improves object creation rates.  As summarized by
@mahrens in #4636:

"Normally, the object allocator simply checks to see if the next
object is available. The slow calls happened when dmu_object_alloc()
checks to see if it can backfill lower object numbers. This happens
every time we move on to a new L1 indirect block (i.e. every 32 *
128 = 4096 objects).  When re-checking lower object numbers, we use
the on-disk fill count (blkptr_t:blk_fill) to quickly skip over
indirect blocks that don’t have enough free dnodes (defined as an L2
with at least 393,216 of 524,288 dnodes free). Therefore, we may
find that a block of dnodes has a low (or zero) fill count, and yet
we can’t allocate any of its dnodes, because they've been allocated
in memory but not yet written to disk. In this case we have to hold
each of the dnodes and then notice that it has been allocated in
memory.

The end result is that allocating N objects in the same TXG can
require CPU usage proportional to N^2."

Add a tunable dmu_rescan_dnode_threshold to define the number of
objects that must be freed before a rescan is performed. Don't bother
to export this as a module option because testing doesn't show a
compelling reason to change it. The vast majority of the performance
gain comes from limit the rescan to at most once per TXG.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-06-24 13:13:12 -07:00
smh
d14fa5dba1 FreeBSD rS271776 - Persist vdev_resilver_txg changes
Persist vdev_resilver_txg changes to avoid panic caused by validation
vs a vdev_resilver_txg value from a previous resilver.

Authored-by: smh <smh@FreeBSD.org>
Ported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/5154
FreeBSD-issue: https://reviews.freebsd.org/rS271776
FreeBSD-commit: https://github.com/freebsd/freebsd/commit/c3c60bf
Closes #4790
2016-06-24 13:02:42 -07:00