The zfs_znode_hold_enter() / zfs_znode_hold_exit() functions are used to
serialize access to a znode and its SA buffer while the object is being
created or destroyed. This kind of locking would normally reside in the
znode itself but in this case that's impossible because the znode and SA
buffer may not yet exist. Therefore the locking is handled externally
with an array of mutexs and AVLs trees which contain per-object locks.
In zfs_znode_hold_enter() a per-object lock is created as needed, inserted
in to the correct AVL tree and finally the per-object lock is held. In
zfs_znode_hold_exit() the process is reversed. The per-object lock is
released, removed from the AVL tree and destroyed if there are no waiters.
This scheme has two important properties:
1) No memory allocations are performed while holding one of the z_hold_locks.
This ensures evict(), which can be called from direct memory reclaim, will
never block waiting on a z_hold_locks which just happens to have hashed
to the same index.
2) All locks used to serialize access to an object are per-object and never
shared. This minimizes lock contention without creating a large number
of dedicated locks.
On the downside it does require znode_lock_t structures to be frequently
allocated and freed. However, because these are backed by a kmem cache
and very short lived this cost is minimal.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4106
Add a zfs_object_mutex_size module option to facilitate resizing the
the per-dataset znode mutex array. Increasing this value may help
make the deadlock described in #4106 less common, but this is not a
proper fix. This patch is primarily to aid debugging and analysis.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue #4106
3465 ::walk ... | ::<dcmd> misinterprets input as symbol names
3466 ::tsd should handle missing/NULL values better
3467 mdb_ctf_vread() could be more useful
3468 mdb enhancements for zfs development
3470 ::whatis does not print callers from KMF_LITE
3473 mdb_get_module() returns wrong module
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
https://www.illumos.org/issues/3468https://github.com/illumos/illumos-gate/commit/28e4da2
Porting notes:
- The only portion of this patch which applies to ZoL is a small
change to types used in the refcount structure.
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4216
Under RHEL6/CentOS6 the default stack size must be increased to 32K
to prevent overflowing the stack when running ztest. This isn't an
issue for other distributions due to either the version of pthreads
or perhaps the compiler. Doubling the stack size resolves the
issue safely for all distribution and leaves us some headroom.
$ sudo -E ztest -V -T 300 -f /var/tmp/
5 vdevs, 7 datasets, 23 threads, 300 seconds...
loading space map for vdev 0 of 1, metaslab 0 of 30 ...
...
loading space map for vdev 0 of 1, metaslab 14 of 30 ...
child died with signal 11
Exited ztest with error 3
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4215
If a thread is holding mutex when doing cv_destroy, it might end up waiting a
thread in cv_wait. The waiter would wake up trying to aquire the same mutex
and cause deadlock.
We solve this by move the mutex_enter to the bottom of cv_wait, so that
the waiter will release the cv first, allowing cv_destroy to succeed and have
a chance to free the mutex.
This would create race condition on the cv_mutex. We use xchg to set and check
it to ensure we won't be harmed by the race. This would result in the cv_mutex
debugging becomes best-effort.
Also, the change reveals a race, which was unlikely before, where we call
mutex_destroy while test threads are still holding the mutex. We use
kthread_stop to make sure the threads are exit before mutex_destroy.
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Issue zfsonlinux/zfs#4166
Issue zfsonlinux/zfs#4106
The spl_kmem_cache_kmem_threads module option was accidentally
omitted from the documentation. Add it.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#512
3749 zfs event processing should work on R/O root filesystems
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3749https://github.com/illumos/illumos-gate/commit/3cb69f7
Porting notes:
- [include/sys/spa_impl.h]
- ffe9d38 Add generic errata infrastructure
- 1421c89 Add visibility in to arc_read
- [include/sys/fm/fs/zfs.h]
- 2668527 Add linux events
- 6283f55 Support custom build directories and move includes
- [module/zfs/spa_config.c]
- Updated spa_config_sync() to match illumos with the exception
of a Linux specific block.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6280 libzfs: unshare_one() could fail with EZFS_SHARENFSFAILED
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References:
https://www.illumos.org/issues/6280https://github.com/illumos/illumos-gate/commit/d1672ef
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
5438 zfs_blkptr_verify should continue after zfs_panic_recover
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Xin LI <delphij@freebsd.org>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/5438https://github.com/illumos/illumos-gate/commit/5897eb4
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6358 A faulted pool with only unavailable vdevs triggers assertion
failure in libzfs
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed by: Serban Maduta <serban.maduta@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://illumos.org/issues/6358https://github.com/illumos/illumos-gate/commit/b289d04
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6171 dsl_prop_unregister() slows down dataset eviction.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/6171https://github.com/illumos/illumos-gate/commit/03bad06
Porting notes:
- Conflicts
- 3558fd7 Prototype/structure update for Linux
- 2cf7f52 Linux compat 2.6.39: mount_nodev()
- 13fe019 Illumos #3464
- 241b541 Illumos 5959 - clean up per-dataset feature count code
- dsl_prop_unregister() preserved until out of tree consumers
like Lustre can transition to dsl_prop_unregister_all().
- Fixing 'space or tab at end of line' in include/sys/dsl_dataset.h
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6288 dmu_buf_will_dirty could be faster
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Justin Gibbs <gibbs@scsiguy.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Robert Mustacchi <rm@joyent.com>
References:
https://www.illumos.org/issues/6288https://github.com/illumos/illumos-gate/commit/0f2e7d0
Porting notes:
- [module/zfs/dbuf.c]
- Fix 'warning: ISO C90 forbids mixed declarations and code'
by moving 'dbuf_dirty_record_t *dr' to start of code block.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
6292 exporting a pool while an async destroy is running can leave
entries in the deferred tree
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Fabian Keil <fk@fabiankeil.de>
Approved by: Gordon Ross <gordon.ross@nexenta.com>
References:
https://www.illumos.org/issues/6292https://github.com/illumos/illumos-gate/commit/a443cc8
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
5039 ztest should default to larger device sizes
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: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/5039https://github.com/illumos/illumos-gate/commit/539eed8
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
kernel.c: In function 'vn_rdwr':
kernel.c:736:8: warning: unused variable 'status' [-Wunused-variable]
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix build failure accidentally introduced by 1715493. This only
results in a failure when debugging is disabled.
dsl_dataset.c: In function 'dsl_dataset_stats':
dsl_dataset.c:1698:45: error: 'dp' undeclared (first use in this function)
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
4929 want prevsnap property
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: Matt Amdur <matt.amdur@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Dan McDonald <danmcd@omniti.com>
References:
https://www.illumos.org/issues/4929https://github.com/illumos/illumos-gate/commit/b461c74
Porting notes:
- [include/sys/fs/zfs.h]
- f67d70 Create an 'overlay' property
- 11b9ec Add full SELinux support
- [fs/zfs/dsl_dataset.c]
- This increases the stack size of dsl_dataset_stats() but
nothing has been changed until this is shown to be an issue.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
4891 want zdb option to dump all metadata
Reviewed by: Sonu Pillai <sonu.pillai@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>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
We'd like a way for zdb to dump metadata in a machine-readable
format, so that we can bring that back from a customer site for
in-house diagnosis. Think of it as a crash dump for zpools,
which can be used for post-mortem analysis of a malfunctioning
pool
References:
https://www.illumos.org/issues/4891https://github.com/illumos/illumos-gate/commit/df15e41
Porting notes:
- [cmd/zdb/zdb.c]
- a5778ea zdb: Introduce -V for verbatim import
- In main() getopt 'opt' variable removed and the code was
brought back in line with illumos.
- [lib/libzpool/kernel.c]
- 1e33ac1 Fix Solaris thread dependency by using pthreads
- f0e324f Update utsname support
- 4d58b69 Fix vn_open/vn_rdwr error handling
- In vn_open() allocate 'dumppath' on heap instead of stack
- Properly handle 'dump_fd == -1' error path
- Free 'realpath' after added vn_dumpdir_code block
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
3749 zfs event processing should work on R/O root filesystems
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>
References:
https://www.illumos.org/issues/3749https://github.com/illumos/illumos-gate/commit/3cb69f7
Porting notes:
- [include/sys/spa_impl.h]
- ffe9d38 Add generic errata infrastructure
- 1421c89 Add visibility in to arc_read
- [include/sys/fm/fs/zfs.h]
- 2668527 Add linux events
- 6283f55 Support custom build directories and move includes
- [module/zfs/spa_config.c]
- Updated spa_config_sync() to match illumos with the exception
of a Linux specific block.
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix an off by one error introduced by fcff0f3 which triggers an
assertion when 16M blocks are used with send/recv. This fix was
intentionally not folder in to the Illumos commit so it can be
easily cherry-picked by upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Add missing getopt specifier for `zdb -V` verbatim option and
set flag with correct bitwise operator.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When casesensitivity=insensitive is set for the
file system, we can deadlock in a rename if the user uses different case
for each path. For example rename("A/some-file.txt", "a/some-file.txt").
The simple test for this is:
1. mkdir some-dir in a ZFS file system
2. touch some-dir/some-file.txt
3. mv Some-dir/some-file.txt some-dir/some-other-file.txt
This last request deadlocks trying to relock the i_mutex on the inode for
the parent directory.
The solution is to use d_add_ci in zpl_lookup if we are on a file system
that has the casesensitivity=insensitive attribute set.
This patch checks if we are working on a case insensitive file system and if
so, allocates storage for the case insensitive name and passes it to
zfs_lookup and then calls d_add_ci instead of d_splice_alias.
The performance impact seems to be minimal even though we have introduced a
kmalloc and kfree in the lookup path.
The problem was found when running Microsoft's FSCT against Samba on top of
ZFS On Linux.
Signed-off-by: Richard Sharpe <realrichardsharpe@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4136
To make arc_summary.py and dbufstat.py compatible with python3
some minor fixes were required, this was done automatically by
`2to3 -w arc_summary.py` and `2to3 -w dbufstat.py`.
Signed-off-by: Hajo Möller <dasjoe@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Reviewed-by: Richard Laager <rlaager@wiktel.com>
3139 zdb dies when it tries to determine path of unlinked file
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
References:
https://github.com/illumos/illumos-gate/commit/1ce39b5https://www.illumos.org/issues/3139
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2077 lots of unreachable breaks in illumos gate
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Richard Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/2077https://github.com/illumos/illumos-gate/commit/33f5ff1
Porting notes:
- Only one file of the original patch applied to ZFS
- Minor formating change to align copyright block with upstream
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
The function sa_update() accepts a 32-bit length parameter and
assigns it to a 16-bit field in sa_bulk_attr_t, potentially
truncating the passed-in value. This could lead to corrupt system
attribute (SA) records getting written to the pool. Add a VERIFY to
sa_update() to detect cases where overflow would occur. The SA length
is limited to 16-bit values by the on-disk format defined by
sa_hdr_phys_t.
The function zfs_sa_set_xattr() is vulnerable to this bug if the
unpacked nvlist of xattrs is less than 64k in size but the packed
size is greater than 64k. Fix this by appropriately checking the
size of the packed nvlist before calling sa_update(). Add error
handling to zpl_xattr_set_sa() to keep the cached list of SA-based
xattrs consistent with the data on disk.
Lastly, zfs_sa_set_xattr() calls dmu_tx_abort() on an assigned
transaction if sa_update() returns an error, but the DMU only allows
unassigned transactions to be aborted. Wrap the sa_update() call in a
VERIFY0, remove the transaction abort, and call dmu_tx_commit()
unconditionally. This is consistent practice with other callers
of sa_update().
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#4150
5745 zfs set allows only one dataset property to be set at a time
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Bayard Bell <buffer.g.overflow@gmail.com>
Reviewed by: Richard PALO <richard@NetBSD.org>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Approved by: Rich Lowe <richlowe@richlowe.net>
References:
https://www.illumos.org/issues/5745https://github.com/illumos/illumos-gate/commit/3092556
Porting notes:
- Fix the missing braces around initializer, zfs_cmd_t zc = {"\0"};
- Remove extra format argument in zfs_do_set()
- Declare at the top:
- zfs_prop_t prop;
- nvpair_t *elem;
- nvpair_t *next;
- int i;
- Additionally initialize:
- int added_resv = 0;
- zfs_prop_t prop = 0;
- Assign 0 install of NULL for uint64_t types.
- zc->zc_nvlist_conf = '\0';
- zc->zc_nvlist_src = '\0';
- zc->zc_nvlist_dst = '\0';
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3574
We need truncate and remove be in the same tx when doing zfs_rmnode on xattr
dir. Otherwise, if we truncate and crash, we'll end up with inconsistent zap
object on the delete queue. We do this by skipping dmu_free_long_range and let
zfs_znode_delete to do the work.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4114
Issue #4052
Issue #4006
Issue #3018
Issue #2861
During zfs_rmnode on a xattr dir, if the system crash just after
dmu_free_long_range, we would get empty xattr dir in delete queue. This would
cause blkid=0 be passed into zap_get_leaf_byblk when doing zfs_purgedir during
mount, and would try to do rw_enter on a wrong structure and cause system
lockup.
We fix this by returning ENOENT when blkid is zero in zap_get_leaf_byblk.
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4114Closes#4052Closes#4006Closes#3018Closes#2861
There exists a lock inversion between the z_xattr_lock and the
z_teardown_lock. Resolve this by taking the z_teardown_lock in
all registered xattr callbacks prior to taking the z_xattr_lock.
This ensures the locks are always taken is the same order thus
preventing a deadlock. Note the z_teardown_lock is taken again
in zfs_lookup() and this is safe because the z_teardown lock is
a re-entrant read reader/writer lock.
* process-1
zpl_xattr_get -> Takes zp->z_xattr_lock
__zpl_xattr_get
zfs_lookup -> Takes zsb->z_teardown_lock in ZFS_ENTER macro
* process-2
zfs_ioc_recv -> Takes zsb->z_teardown_lock in zfs_suspend_fs()
zfs_resume_fs
zfs_rezget -> Takes zp->z_xattr_lock
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes#3943Closes#3969Closes#4121
Commit efc412b updated spa_config_write() for Linux 4.2 kernels to
truncate and overwrite rather than rename the cache file. This is
the correct fix but it should have only been applied for the kernel
build. In user space rename(2) is needed because ztest depends on
the cache file.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4129
The do_div() macro expects unsigned types and this is detected in
powerpc implementation of do_div().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#516
When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible
recursive locking in some cases and possible circular locking dependency
in others, within the SPL and ZFS modules.
This patch uses a mutex type defined in SPL, MUTEX_NOLOCKDEP, to mark
such mutexes when they are initialized. This mutex type causes
attempts to take or release those locks to be wrapped in lockdep_off()
and lockdep_on() calls to silence the dependency checker and allow the
use of lock_stats to examine contention.
For RW locks, it uses an analogous lock type, RW_NOLOCKDEP.
The goal is that these locks are ultimately changed back to type
MUTEX_DEFAULT or RW_DEFAULT, after the locks are annotated to reflect
their relationship (e.g. z_name_lock below) or any real problem with the
lock dependencies are fixed.
Some of the affected locks are:
tc_open_lock:
=============
This is an array of locks, all with same name, which txg_quiesce must
take all of in order to move txg to next state. All default to the same
lockdep class, and so to lockdep appears recursive.
zp->z_name_lock:
================
In zfs_rmdir,
dzp = znode for the directory (input to zfs_dirent_lock)
zp = znode for the entry being removed (output of zfs_dirent_lock)
zfs_rmdir()->zfs_dirent_lock() takes z_name_lock in dzp
zfs_rmdir() takes z_name_lock in zp
Since both dzp and zp are type znode_t, the locks have the same default
class, and lockdep considers it a possible recursive lock attempt.
l->l_rwlock:
============
zap_expand_leaf() sometimes creates two new zap leaf structures, via
these call paths:
zap_deref_leaf()->zap_get_leaf_byblk()->zap_leaf_open()
zap_expand_leaf()->zap_create_leaf()->zap_expand_leaf()->zap_create_leaf()
Because both zap_leaf_open() and zap_create_leaf() initialize
l->l_rwlock in their (separate) leaf structures, the lockdep class is
the same, and the linux kernel believes these might both be the same
lock, and emits a possible recursive lock warning.
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3895
