Commit Graph

137 Commits

Author SHA1 Message Date
Rob Norris
c22d56e3ed zfs_znode: lift common code to a single shared file
For now, userspace has no znode implementation. Some of the property and
path handling code is used there though and is the same on all
platforms, so we only need a single copy of it.

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/
Closes #16492
2024-09-19 15:49:45 -07:00
Matthew Macy
bced7e3aaa OpenZFS restructuring - move platform specific sources
Move platform specific Linux source under module/os/linux/
and update the build system accordingly.  Additional code
restructuring will follow to make the common code fully
portable.
    
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Macy <mmacy@FreeBSD.org>
Closes #9206
2019-09-06 11:26:26 -07:00
Andrea Gelmini
e1cfd73f7f Fix typos in module/zfs/
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #9240
2019-09-02 17:56:41 -07:00
Tom Caputi
e7a2fa70c3 Fix deadlock in 'zfs rollback'
Currently, the 'zfs rollback' code can end up deadlocked due to
the way the kernel handles unreferenced inodes on a suspended fs.
Essentially, the zfs_resume_fs() code path may cause zfs to spawn
new threads as it reinstantiates the suspended fs's zil. When a
new thread is spawned, the kernel may attempt to free memory for
that thread by freeing some unreferenced inodes. If it happens to
select inodes that are a a part of the suspended fs a deadlock
will occur because freeing inodes requires holding the fs's
z_teardown_inactive_lock which is still held from the suspend.

This patch corrects this issue by adding an additional reference
to all inodes that are still present when a suspend is initiated.
This prevents them from being freed by the kernel for any reason.

Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #9203
2019-08-27 09:55:51 -07:00
Tomohiro Kusumi
a43570c5f3 Change boolean-like uint8_t fields in znode_t to boolean_t
Given znode_t is an in-core structure, it's more readable to have
them as boolean. Also co-locate existing boolean fields with them
for space efficiency (expecting 8 booleans to be packed/aligned).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes #9092
2019-08-13 07:58:02 -06:00
Tom Caputi
3ce85b5e60 Fix integer overflow of ZTOI(zp)->i_generation
The ZFS on-disk format stores each inode's generation ID as a 64
bit number on disk and in-core. However, the Linux kernel's inode
is only a 32 bit number. In most places, the code handles this
correctly, but the cast is missing in zfs_rezget(). For many pools,
this isn't an issue since the generation ID is computed as the
current txg when the inode is created and many pools don't have
more than 2^32 txgs.

For the pools that have more txgs, this issue causes any inode with
a high enough generation number to report IO errors after a call to
"zfs rollback" while holding the file or directory open. This patch
simply adds the missing cast.

Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8858
2019-06-06 12:59:39 -07:00
Tomohiro Kusumi
1a6889947e Drop objid argument in zfs_znode_alloc() (sync with OpenZFS)
Since zfs_znode_alloc() already takes dmu_buf_t*, taking another
uint64_t argument for objid is redundant. inode's ->i_ino does and
needs to match znode's ->z_id.

zfs_znode_alloc() in FreeBSD and illumos doesn't have this argument
since vnode doesn't have vnode# in VFS (hence ->z_id exists).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@osnexus.com>
Closes #8841
2019-06-05 14:18:46 -07:00
Tomohiro Kusumi
841a7a98fc Update descriptions for vnops
These descriptions are not uptodate with the code.

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes #8767
2019-05-25 14:29:10 -07:00
Tomohiro Kusumi
9c53e51616 Fix zfs set atime|relatime=off|on behavior on inherited datasets
`zfs set atime|relatime=off|on` doesn't disable or enable the property
on read for datasets whose property was inherited from parent, until
a dataset is once unmounted and mounted again.

(The properties start to work properly if a dataset is once unmounted
and mounted again. The difference comes from regular mount process,
e.g. via zpool import, uses mount options based on properties read
from ondisk layout for each dataset, whereas
`zfs set atime|relatime=off|on` just remounts a specified dataset.)

--
 # zpool create p1 <device>
 # zfs create p1/f1
 # zfs set atime=off p1
 # echo test > /p1/f1/test
 # sync
 # zfs list
 NAME    USED  AVAIL     REFER  MOUNTPOINT
 p1      176K  18.9G     25.5K  /p1
 p1/f1    26K  18.9G       26K  /p1/f1
 # zfs get atime
 NAME   PROPERTY  VALUE  SOURCE
 p1     atime     off    local
 p1/f1  atime     off    inherited from p1
 # stat /p1/f1/test | grep Access | tail -1
 Access: 2019-04-26 23:32:33.741205192 +0900
 # cat /p1/f1/test
 test
 # stat /p1/f1/test | grep Access | tail -1
 Access: 2019-04-26 23:32:50.173231861 +0900
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ changed by read(2)
--

The problem is that zfsvfs::z_atime which was probably intended to keep
incore atime state just gets updated by a callback function of "atime"
property change, atime_changed_cb(), and never used for anything else.

Since now that all file read and atime update use a common function
zpl_iter_read_common() -> file_accessed(), and whether to update atime
via ->dirty_inode() is determined by atime_needs_update(),
atime_needs_update() needs to return false once atime is turned off.
It currently continues to return true on `zfs set atime=off`.

Fix atime_changed_cb() by setting or dropping SB_NOATIME in VFS super
block depending on a new atime value, so that atime_needs_update() works
as expected after property change.

The same problem applies to "relatime" except that a self contained
relatime test is needed. This is because relatime_need_update() is based
on a mount option flag MNT_RELATIME, which doesn't exist in datasets
with inherited "relatime" property via `zfs set relatime=...`, hence it
needs its own relatime test zfs_relatime_need_update().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes #8674 
Closes #8675
2019-05-07 10:06:30 -07:00
Tomohiro Kusumi
34d343c2a8 Drop unused ZNODE_STATS and ZNODE_STAT_ADD()
Unused since 5649246dd3("Remove znode move functionality"),
and ZNODE_STAT_ADD() will never be needed.

Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Closes #8636
2019-04-19 12:05:15 -07:00
Alek P
dcec0a12c8 port async unlinked drain from illumos-nexenta
This patch is an async implementation of the existing sync
zfs_unlinked_drain() function. This function is called at mount time and
is responsible for freeing znodes that we didn't get to freeing before.
We don't have to hold mounting of the dataset until the unlinked list is
fully drained as is done now. Since we can process the unlinked set
asynchronously this results in a better user experience when mounting a
dataset with entries in the unlinked set.

Reviewed by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes #8142
2019-02-12 10:41:15 -08:00
Matthew Ahrens
49394a7708 Linux does not HAVE_SMB_SHARE
Since Linux does not have an in-kernel SMB server, we don't need the
code to manage it.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #8032
2018-10-17 10:31:38 -07:00
Matt Ahrens
5d43cc9a59 OpenZFS 9689 - zfs range lock code should not be zpl-specific
The ZFS range locking code in zfs_rlock.c/h depends on ZPL-specific
data structures, specifically znode_t.  However, it's also used by
the ZVOL code, which uses a "dummy" znode_t to pass to the range
locking code.

We should clean this up so that the range locking code is generic
and can be used equally by ZPL and ZVOL, and also can be used by
future consumers that may need to run in userland (libzpool) as
well as the kernel.

Porting notes:
* Added missing sys/avl.h include to sys/zfs_rlock.h.
* Removed 'dbuf is within the locked range' ASSERTs from dmu_sync().
  This was needed because ztest does not yet use a locked_range_t.
* Removed "Approved by:" tag requirement from OpenZFS commit
  check to prevent needless warnings when integrating changes
  which has not been merged to illumos.
* Reverted free_list range lock changes which were originally
  needed to defer the cv_destroy() which was called immediately
  after cv_broadcast().  With d2733258 this should be safe but
  if not we may need to reintroduce this logic.
* Reverts: The following two commits were reverted and squashed in
  to this change in order to make it easier to apply OpenZFS 9689.
  - d88895a0, which removed the dummy znode from zvol_state
  - e3a07cd0, which updated ztest to use range locks
* Preserved optimized rangelock comparison function.  Preserved the
  rangelock free list.  The cv_destroy() function will block waiting
  for all processes in cv_wait() to be scheduled and drop their
  reference.  This is done to ensure it's safe to free the condition
  variable.  However, blocking while holding the rl->rl_lock mutex
  can result in a deadlock on Linux.  A free list is introduced to
  defer the cv_destroy() and kmem_free() until after the mutex is
  released.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9689
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/680
External-issue: DLPX-58662
Closes #7980
2018-10-11 10:19:33 -07:00
Tim Schumacher
424fd7c3e0 Prefix all refcount functions with zfs_
Recent changes in the Linux kernel made it necessary to prefix
the refcount_add() function with zfs_ due to a name collision.

To bring the other functions in line with that and to avoid future
collisions, prefix the other refcount functions as well.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes #7963
2018-10-01 10:42:05 -07:00
Tim Schumacher
c13060e478 Linux 4.19-rc3+ compat: Remove refcount_t compat
torvalds/linux@59b57717f ("blkcg: delay blkg destruction until
after writeback has finished") added a refcount_t to the blkcg
structure. Due to the refcount_t compatibility code, zfs_refcount_t
was used by mistake.

Resolve this by removing the compatibility code and replacing the
occurrences of refcount_t with zfs_refcount_t.

Reviewed-by: Franz Pletz <fpletz@fnordicwalking.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes #7885 
Closes #7932
2018-09-26 10:29:26 -07:00
Brian Behlendorf
6413c95fbd
Linux 4.18 compat: inode timespec -> timespec64
Commit torvalds/linux@95582b0 changes the inode i_atime, i_mtime,
and i_ctime members form timespec's to timespec64's to make them
2038 safe.  As part of this change the current_time() function was
also updated to return the timespec64 type.

Resolve this issue by introducing a new inode_timespec_t type which
is defined to match the timespec type used by the inode.  It should
be used when working with inode timestamps to ensure matching types.

The timestruc_t type under Illumos was used in a similar fashion but
was specified to always be a timespec_t.  Rather than incorrectly
define this type all timespec_t types have been replaced by the new
inode_timespec_t type.

Finally, the kernel and user space 'sys/time.h' headers were aligned
with each other.  They define as appropriate for the context several
constants as macros and include static inline implementation of
gethrestime(), gethrestime_sec(), and gethrtime().

Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7643
2018-06-19 21:51:18 -07:00
Brian Behlendorf
93ce2b4ca5 Update build system and packaging
Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.

Build system and packaging:
  * Renamed SPL_* autoconf m4 macros to ZFS_*.
  * Removed redundant SPL_* autoconf m4 macros.
  * Updated the RPM spec files to remove SPL package dependency.
  * The zfs package obsoletes the spl package, and the zfs-kmod
    package obsoletes the spl-kmod package.
  * The zfs-kmod-devel* packages were updated to add compatibility
    symlinks under /usr/src/spl-x.y.z until all dependent packages
    can be updated.  They will be removed in a future release.
  * Updated copy-builtin script for in-kernel builds.
  * Updated DKMS package to include the spl.ko.
  * Updated stale AUTHORS file to include all contributors.
  * Updated stale COPYRIGHT and included the SPL as an exception.
  * Renamed README.markdown to README.md
  * Renamed OPENSOLARIS.LICENSE to LICENSE.
  * Renamed DISCLAIMER to NOTICE.

Required code changes:
  * Removed redundant HAVE_SPL macro.
  * Removed _BOOT from nvpairs since it doesn't apply for Linux.
  * Initial header cleanup (removal of empty headers, refactoring).
  * Remove SPL repository clone/build from zimport.sh.
  * Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
    to build issues when forcing C99 compilation.
  * Replaced legacy ACCESS_ONCE with READ_ONCE.
  * Include needed headers for `current` and `EXPORT_SYMBOL`.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes #7556
2018-05-29 16:00:33 -07:00
Paul Dagnelie
64c1dcefe3 OpenZFS 9421, 9422 - zdb show possibly leaked objects
9421 zdb should detect and print out the number of "leaked" objects
9422 zfs diff and zdb should explicitly mark objects that are on
     the deleted queue

It is possible for zfs to "leak" objects in such a way that they are not
freed, but are also not accessible via the POSIX interface. As the only
way to know that this is happened is to see one of them directly in a
zdb run, or by noting unaccounted space usage, zdb should be enhanced to
count these objects and return failure if some are detected.

We have access to the delete queue through the zfs_get_deleteq function;
we should call it in dump_znode to determine if the object is on the
delete queue. This is not the most efficient possible method, but it is
the simplest to implement, and should suffice for the common case where
there few objects on the delete queue.

Also zfs diff and zdb currently traverse every single dnode in a dataset
and tries to figure out the path of the object by following it's parent.
When an object is placed on the delete queue, for all practical purposes
it's already discarded, it's parent might not exist anymore, and another
object might now have the object number that belonged to the parent.
While all of the above makes sense, when trying to figure out the path
of an object that is on the delete queue, we can run into issues where
either it is impossible to determine the path because the parent is
gone, or another dnode has taken it's place and thus we are returned a
wrong path.

We should therefore avoid trying to determine the path of an object on
the delete queue and mark the object itself as being on the delete queue
to avoid confusion. To achieve this, we currently have two ideas:

1. When putting an object on the delete queue, change it's parent object
   number to a known constant that means NULL.

2. When displaying objects, first check if it is present on the delete
   queue.

Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Matt Ahrens <mahrens@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9421
OpenZFS-issue: https://illumos.org/issues/9422
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45ae0dd9ca
Closes #7500
2018-05-04 10:50:24 -07:00
Nasf-Fan
9c5167d19f Project Quota on ZFS
Project quota is a new ZFS system space/object usage accounting
and enforcement mechanism. Similar as user/group quota, project
quota is another dimension of system quota. It bases on the new
object attribute - project ID.

Project ID is a numerical value to indicate to which project an
object belongs. An object only can belong to one project though
you (the object owner or privileged user) can change the object
project ID via 'chattr -p' or 'zfs project [-s] -p' explicitly.
The object also can inherit the project ID from its parent when
created if the parent has the project inherit flag (that can be
set via 'chattr +P' or 'zfs project -s [-p]').

By accounting the spaces/objects belong to the same project, we
can know how many spaces/objects used by the project. And if we
set the upper limit then we can control the spaces/objects that
are consumed by such project. It is useful when multiple groups
and users cooperate for the same project, or a user/group needs
to participate in multiple projects.

Support the following commands and functionalities:

zfs set projectquota@project
zfs set projectobjquota@project

zfs get projectquota@project
zfs get projectobjquota@project
zfs get projectused@project
zfs get projectobjused@project

zfs projectspace

zfs allow projectquota
zfs allow projectobjquota
zfs allow projectused
zfs allow projectobjused

zfs unallow projectquota
zfs unallow projectobjquota
zfs unallow projectused
zfs unallow projectobjused

chattr +/-P
chattr -p project_id
lsattr -p

This patch also supports tree quota based on the project quota via
"zfs project" commands set as following:
zfs project [-d|-r] <file|directory ...>
zfs project -C [-k] [-r] <file|directory ...>
zfs project -c [-0] [-d|-r] [-p id] <file|directory ...>
zfs project [-p id] [-r] [-s] <file|directory ...>

For "df [-i] $DIR" command, if we set INHERIT (project ID) flag on
the $DIR, then the proejct [obj]quota and [obj]used values for the
$DIR's project ID will be shown as the total/free (avail) resource.
Keep the same behavior as EXT4/XFS does.

Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by  Ned Bass <bass6@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fan Yong <fan.yong@intel.com>
TEST_ZIMPORT_POOLS="zol-0.6.1 zol-0.6.2 master"
Change-Id: Ib4f0544602e03fb61fd46a849d7ba51a6005693c
Closes #6290
2018-02-13 14:54:54 -08:00
Andriy Gapon
6a2185660d OpenZFS 8930 - zfs_zinactive: do not remove the node if the filesystem is readonly
Authored by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/8930
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/93c618e0f4
Closes #7029
2018-01-11 13:50:08 -08:00
Feng Sun
18a2485fc8 misc: fix meaningless values
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Feng Sun <loyou85@gmail.com>
Closes #6658
2017-09-19 12:19:08 -07:00
Brian Behlendorf
9631681b75 Fix dnode allocation race
When performing concurrent object allocations using the new
multi-threaded allocator and large dnodes it's possible to
allocate overlapping large dnodes.

This case should have been handled by detecting an error
returned by dnode_hold_impl().  But that logic only checked
the returned dnp was not-NULL, and the dnp variable was not
reset to NULL when retrying.  Resolve this issue by properly
checking the return value of dnode_hold_impl().

Additionally, it was possible that dnode_hold_impl() would
misreport a dnode as free when it was in fact in use.  This
could occurs for two reasons:

* The per-slot zrl_lock must be held over the entire critical
  section which includes the alloc/free until the new dnode
  is assigned to children_dnodes.  Additionally, all of the
  zrl_lock's in the range must be held to protect moving
  dnodes.

* The dn->dn_ot_type cannot be solely relied upon to check
  the type.  When allocating a new dnode its type will be
  DMU_OT_NONE after dnode_create().  Only latter when
  dnode_allocate() is called will it transition to the new
  type.  This means there's a window when allocating where
  it can mistaken for a free dnode.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6414 
Closes #6439
2017-08-08 08:38:53 -07:00
Ned Bass
ecb2b7dc7f Use SET_ERROR for constant non-zero return codes
Update many return and assignment statements to follow the convention
of using the SET_ERROR macro when returning a hard-coded non-zero
value from a function. This aids debugging by recording the error
codes in the debug log.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #6441
2017-08-02 21:16:12 -07:00
Matthew Ahrens
dbeb879699 OpenZFS 8199 - multi-threaded dmu_object_alloc()
dmu_object_alloc() is single-threaded, so when multiple threads are
creating files in a single filesystem, they spend a lot of time waiting
for the os_obj_lock.  To improve performance of multi-threaded file
creation, we must make dmu_object_alloc() typically not grab any
filesystem-wide locks.

The solution is to have a "next object to allocate" for each CPU. Each
of these "next object"s is in a different block of the dnode object, so
that concurrent allocation holds dnodes in different dbufs.  When a
thread's "next object" reaches the end of a chunk of objects (by default
4 blocks worth -- 128 dnodes), it will be reset to the per-objset
os_obj_next, which will be increased by a chunk of objects (128).  Only
when manipulating the os_obj_next will we need to grab the os_obj_lock.
This decreases lock contention dramatically, because each thread only
needs to grab the os_obj_lock briefly, once per 128 allocations.

This results in a 70% performance improvement to multi-threaded object
creation (where each thread is creating objects in its own directory),
from 67,000/sec to 115,000/sec, with 8 CPUs.

Work sponsored by Intel Corp.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>

OpenZFS-issue: https://www.illumos.org/issues/8199
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/374
Closes #4703
Closes #6117
2017-06-09 09:43:26 -07:00
Gvozden Neskovic
c17486b217 Add missing *_destroy/*_fini calls
The proposed debugging enhancements in zfsonlinux/spl#587
identified the following missing *_destroy/*_fini calls.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #5428
2017-05-04 19:26:28 -04:00
Brian Behlendorf
8d70398740 Retry zfs_znode_alloc() in zfs_mknode()
For historical reasons zfs_mknode() was written such that it could
never fail.  This poses a problem for Linux since zfs_znode_alloc()
could potentually failure due to low memory.  Handle this gracefully
by retrying zfs_znode_alloc() until it succeeds, direct reclaim
will eventually be able to allocate memory.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5535 
Closes #5908
2017-03-23 18:26:50 -07:00
Brian Behlendorf
0037b49e83 Rename zfs_sb_t -> zfsvfs_t
The use of zfs_sb_t instead of zfsvfs_t results in unnecessary
conflicts with the upstream source.  Change all instances of
zfs_sb_t to zfsvfs_t including updating the variables names.

Whenever possible the code was updated to be consistent with
hope it appears in the upstream OpenZFS source.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2017-03-10 09:51:33 -08:00
Chunwei Chen
a5248129b8 Use inode_set_flags when available
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-12-16 13:54:51 -08:00
Chunwei Chen
7bb1325f95 Fix i_flags issue caused by 64c688d
Fix zfs_xvattr_set to set S_IMMUTABLE and S_APPEND flags correctly.

Reinstate zfs_set_inode_flags and use it when zfs_xvatter_set and also when
setting up inode in zfs_znode_alloc and zfs_rezget.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-12-14 14:48:09 -08:00
Brian Behlendorf
02730c333c Use cstyle -cpP in make cstyle check
Enable picky cstyle checks and resolve the new warnings.  The vast
majority of the changes needed were to handle minor issues with
whitespace formatting.  This patch contains no functional changes.

Non-whitespace changes are as follows:

* 8 times ; to { } in for/while loop
* fix missing ; in cmd/zed/agents/zfs_diagnosis.c
* comment (confim -> confirm)
* change endline , to ; in cmd/zpool/zpool_main.c
* a number of /* BEGIN CSTYLED */ /* END CSTYLED */ blocks
* /* CSTYLED */ markers
* change == 0 to !
* ulong to unsigned long in module/zfs/dsl_scan.c
* rearrangement of module_param lines in module/zfs/metaslab.c
* add { } block around statement after for_each_online_node

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5465
2016-12-12 10:46:26 -08:00
Chunwei Chen
ace1eae84c Add support for O_TMPFILE
Linux 3.11 add O_TMPFILE to open(2), which allow creating an unlinked file on
supported filesystem. It's basically doing open(2) and unlink(2) atomically.

The filesystem support is added through i_op->tmpfile. We basically copy the
create operation except we get rid of the link and name related stuff and add
the new node to unlinked set.

We also add support for linkat(2) to link tmpfile. However, since all previous
file operation will skip ZIL, we force a txg_wait_synced to make sure we are
sync safe.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-11-04 10:46:40 -07:00
Chunwei Chen
987014903f Fix unlinked file cannot do xattr operations
Currently, doing things like fsetxattr(2) on an unlinked file will result in
ENODATA. There's two places that cause this: zfs_dirent_lock and zfs_zget.

The fix in zfs_dirent_lock is pretty straightforward. In zfs_zget though, we
need it to not return error when the zp is unlinked. This is a pretty big
change in behavior, but skimming through all the callers, I don't think this
change would cause any problem. Also there's nothing preventing z_unlinked
from being set after the z_lock mutex is dropped before but before zfs_zget
returns anyway.

The rest of the stuff is to make sure we don't log xattr stuff when owner is
unlinked.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
2016-11-04 10:46:40 -07:00
lorddoskias
64c688d716 Refactor updating of immutable/appendonly flags
Move the synchronization of inode/znode i_flgas/pflags into
the respective internal zfs function. This is mostly
mechanical work and shouldn't introduce any functional
changes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Issue #227 
Closes #5223
2016-10-05 14:47:29 -07:00
luozhengzheng
aecdc70604 Fix coverity defects: CID 147448, 147449, 147450, 147453, 147454
coverity scan CID:147448,type: unchecked return value
coverity scan CID:147449,type: unchecked return value
coverity scan CID:147450,type: unchecked return value
coverity scan CID:147453,type: unchecked return value
coverity scan CID:147454,type: unchecked return value

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: luozhengzheng <luo.zhengzheng@zte.com.cn>
Closes #5206
2016-10-02 11:24:54 -07:00
lorddoskias
12fa7f3436 Refactor inode->i_mode management
Refactor the code in such a way so that inode->i_mode is being set
at the same time zp->z_mode is being changed. This has the effect of
keeping both in sync without relying on zfs_inode_update.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Closes #5158
2016-09-27 14:08:52 -07:00
Nikolay Borisov
9f5f0019ab Refactor generic inode time updating
ZFS doesn't provide a custom update_time method meaning it delegates
this job to the generic VFS layer. The only time when it needs to
set the various *time values is when the inode is being marshalled
to/from the disk. Do this by moving the relevant code from
zfs_inode_update_impl to zfs_node_alloc and zfs_rezget. As a result
from this change it is no longer necessary to have multiple versions
of the zfs_inode_update function - so just nuke them and leave only
one.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Issue #227
Closes #4916
2016-09-13 11:57:37 -07:00
Gvozden Neskovic
ee36c709c3 Performance optimization of AVL tree comparator functions
perf: 2.75x faster ddt_entry_compare()
    First 256bits of ddt_key_t is a block checksum, which are expected
to be close to random data. Hence, on average, comparison only needs to
look at first few bytes of the keys. To reduce number of conditional
jump instructions, the result is computed as: sign(memcmp(k1, k2)).

Sign of an integer 'a' can be obtained as: `(0 < a) - (a < 0)` := {-1, 0, 1} ,
which is computed efficiently.  Synthetic performance evaluation of
original and new algorithm over 1G random keys on 2.6GHz Intel(R) Xeon(R)
CPU E5-2660 v3:

old	6.85789 s
new	2.49089 s

perf: 2.8x faster vdev_queue_offset_compare() and vdev_queue_timestamp_compare()
    Compute the result directly instead of using conditionals

perf: zfs_range_compare()
    Speedup between 1.1x - 2.5x, depending on compiler version and
optimization level.

perf: spa_error_entry_compare()
    `bcmp()` is not suitable for comparator use. Use `memcmp()` instead.

perf: 2.8x faster metaslab_compare() and metaslab_rangesize_compare()
perf: 2.8x faster zil_bp_compare()
perf: 2.8x faster mze_compare()
perf: faster dbuf_compare()
perf: faster compares in spa_misc
perf: 2.8x faster layout_hash_compare()
perf: 2.8x faster space_reftree_compare()
perf: libzfs: faster avl tree comparators
perf: guid_compare()
perf: dsl_deadlist_compare()
perf: perm_set_compare()
perf: 2x faster range_tree_seg_compare()
perf: faster unique_compare()
perf: faster vdev_cache _compare()
perf: faster vdev_uberblock_compare()
perf: faster fuid _compare()
perf: faster zfs_znode_hold_compare()

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Richard Elling <richard.elling@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5033
2016-08-31 14:35:34 -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
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
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
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
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
Chunwei Chen
cbecb4fb22 Skip ctldir znode in zfs_rezget to fix snapdir issues
Skip ctldir in zfs_rezget, otherwise they will always get invalidated. This
will cause funny behaviour for the mounted snapdirs. Especially for
Linux >= 3.18, d_invalidate will detach the mountpoint and prevent anyone
automount it again as long as someone is still using the detached mount.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4514
Closes #4661
Closes #4672
2016-05-23 11:06:56 -07:00
Nikolay Borisov
278f223668 Kill znode->z_gen field
This field is a duplicate of the inode->i_generation, so just
kill it.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4538
Closes #4654
2016-05-19 13:06:14 -07:00
Chunwei Chen
d88895a069 Remove dummy znode from zvol_state
struct zvol_state contains a dummy znode, which is around 1KB on x64,
only for zfs_range_lock. But in reality, other than z_range_lock and
z_range_avl, zfs_range_lock only need znode on regular file, which
means we add 1KB on a structure and gain nothing.

In this patch, we remove the dummy znode for zvol_state. In order to
do that, we also need to refactor zfs_range_lock a bit. We move
z_range_lock and z_range_avl pair out of znode_t to form zfs_rlock_t.
This new struct replaces znode_t as the main handle inside the range
lock functions.

We also add pointers to z_size, z_blksz, and z_max_blksz so range lock
code doesn't depend on znode_t.  This allows non-ZPL consumers like
Lustre to use the range locks with their equivalent znode_t structure.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Boris Protopopov <boris.protopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4510
2016-05-17 10:29:02 -07:00
Brian Behlendorf
c15706490e Revert "Kill znode->z_gen field"
This reverts commit 4cd77889b6.  The
i_generation field in the inode is 32-bit and the SA code expects
64-bit fixed values.  Revert this optimization for now until
this is cleanly addressed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4538
2016-05-12 13:36:22 -07:00
Nikolay Borisov
4cd77889b6 Kill znode->z_gen field
This field is a duplicate of the inode->i_generation, so just kill it

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4538
2016-05-02 11:22:31 -07:00
Chunwei Chen
704cd0758a Enable lazytime semantic for atime
Linux 4.0 introduces lazytime. The idea is that when we update the atime, we
delay writing it to disk for as long as it is reasonably possible.

When lazytime is enabled, dirty_inode will be called with only I_DIRTY_TIME
flag whenever i_atime is updated. So under such condition, we will set
z_atime_dirty. We will only write it to disk if file is closed, inode is
evicted or setattr is called. Ideally, we should also write it whenever SA
is going to be updated, but it is left for future improvement.

There's one thing that we should take care of now that we allow i_atime to be
dirty. In original implementation, whenever SA is modified, zfs_inode_update
will be called to overwrite every thing in inode. This will cause dirty
i_atime to be discarded. We fix this by don't overwrite i_atime in
zfs_inode_update. We only overwrite i_atime when allocating new inode or doing
zfs_rezget with zfs_inode_update_new.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4482
2016-04-05 18:55:51 -07:00
Chunwei Chen
0df9673f01 Fix atime handling and relatime
The problem for atime:

We have 3 places for atime: inode->i_atime, znode->z_atime and SA. And its
handling is a mess. A huge part of mess regarding atime comes from
zfs_tstamp_update_setup, zfs_inode_update, and zfs_getattr, which behave
inconsistently with those three values.

zfs_tstamp_update_setup clears z_atime_dirty unconditionally as long as you
don't pass ATTR_ATIME. Which means every write(2) operation which only updates
ctime and mtime will cause atime changes to not be written to disk.

Also zfs_inode_update from write(2) will replace inode->i_atime with what's
inside SA(stale). But doesn't touch z_atime. So after read(2) and write(2).
You'll have i_atime(stale), z_atime(new), SA(stale) and z_atime_dirty=0.

Now, if you do stat(2), zfs_getattr will actually replace i_atime with what's
inside, z_atime. So you will have now you'll have i_atime(new), z_atime(new),
SA(stale) and z_atime_dirty=0. These will all gone after umount. And you'll
leave with a stale atime.

The problem for relatime:

We do have a relatime config inside ZFS dataset, but how it should interact
with the mount flag MS_RELATIME is not well defined. It seems it wanted
relatime mount option to override the dataset config by showing it as
temporary in `zfs get`. But at the same time, `zfs set relatime=on|off` would
also seems to want to override the mount option. Not to mention that
MS_RELATIME flag is actually never passed into ZFS, so it never really worked.

How Linux handles atime:

The Linux kernel actually handles atime completely in VFS, except for writing
it to disk. So if we remove the atime handling in ZFS, things would just work,
no matter it's strictatime, relatime, noatime, or even O_NOATIME. And whenever
VFS updates the i_atime, it will notify the underlying filesystem via
sb->dirty_inode().

And also there's one thing to note about atime flags like MS_RELATIME and
other flags like MS_NODEV, etc. They are mount point flags rather than
filesystem(sb) flags. Since native linux filesystem can be mounted at multiple
places at the same time, they can all have different atime settings. So these
flags are never passed down to filesystem drivers.

What this patch tries to do:

We remove znode->z_atime, since we won't gain anything from it. We remove most
of the atime handling and leave it to VFS. The only thing we do with atime is
to write it when dirty_inode() or setattr() is called. We also add
file_accessed() in zpl_read() since it's not provided in vfs_read().

After this patch, only the MS_RELATIME flag will have effect. The setting in
dataset won't do anything. We will make zfstuil to mount ZFS with MS_RELATIME
set according to the setting in dataset in future patch.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4482
2016-04-05 18:54:55 -07:00
Brian Behlendorf
8b1899d3fb Linux 4.6 compat: PAGE_CACHE_SIZE removal
As described in torvalds/linux@4a2d057e the macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were originally introduced
to make it possible to add bigger chunks to the page cache.  This
never panned out and it has therefore been removed from the kernel.

ZFS has been updated to use the PAGE_{SIZE,SHIFT,MASK,ALIGN} macros
and calls to page_cache_release() have been replaced with put_page().

There was no need to introduce a configure check for this because
these interfaces have existed for a very long time.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes #4489
2016-04-05 17:26:56 -07:00