Adding O_DIRECT support to ZFS to bypass the ARC for writes/reads.
O_DIRECT support in ZFS will always ensure there is coherency between
buffered and O_DIRECT IO requests. This ensures that all IO requests,
whether buffered or direct, will see the same file contents at all
times. Just as in other FS's , O_DIRECT does not imply O_SYNC. While
data is written directly to VDEV disks, metadata will not be synced
until the associated TXG is synced.
For both O_DIRECT read and write request the offset and request sizes,
at a minimum, must be PAGE_SIZE aligned. In the event they are not,
then EINVAL is returned unless the direct property is set to always (see
below).
For O_DIRECT writes:
The request also must be block aligned (recordsize) or the write
request will take the normal (buffered) write path. In the event that
request is block aligned and a cached copy of the buffer in the ARC,
then it will be discarded from the ARC forcing all further reads to
retrieve the data from disk.
For O_DIRECT reads:
The only alignment restrictions are PAGE_SIZE alignment. In the event
that the requested data is in buffered (in the ARC) it will just be
copied from the ARC into the user buffer.
For both O_DIRECT writes and reads the O_DIRECT flag will be ignored in
the event that file contents are mmap'ed. In this case, all requests
that are at least PAGE_SIZE aligned will just fall back to the buffered
paths. If the request however is not PAGE_SIZE aligned, EINVAL will
be returned as always regardless if the file's contents are mmap'ed.
Since O_DIRECT writes go through the normal ZIO pipeline, the
following operations are supported just as with normal buffered writes:
Checksum
Compression
Encryption
Erasure Coding
There is one caveat for the data integrity of O_DIRECT writes that is
distinct for each of the OS's supported by ZFS.
FreeBSD - FreeBSD is able to place user pages under write protection so
any data in the user buffers and written directly down to the
VDEV disks is guaranteed to not change. There is no concern
with data integrity and O_DIRECT writes.
Linux - Linux is not able to place anonymous user pages under write
protection. Because of this, if the user decides to manipulate
the page contents while the write operation is occurring, data
integrity can not be guaranteed. However, there is a module
parameter `zfs_vdev_direct_write_verify` that controls the
if a O_DIRECT writes that can occur to a top-level VDEV before
a checksum verify is run before the contents of the I/O buffer
are committed to disk. In the event of a checksum verification
failure the write will return EIO. The number of O_DIRECT write
checksum verification errors can be observed by doing
`zpool status -d`, which will list all verification errors that
have occurred on a top-level VDEV. Along with `zpool status`, a
ZED event will be issues as `dio_verify` when a checksum
verification error occurs.
ZVOLs and dedup is not currently supported with Direct I/O.
A new dataset property `direct` has been added with the following 3
allowable values:
disabled - Accepts O_DIRECT flag, but silently ignores it and treats
the request as a buffered IO request.
standard - Follows the alignment restrictions outlined above for
write/read IO requests when the O_DIRECT flag is used.
always - Treats every write/read IO request as though it passed
O_DIRECT and will do O_DIRECT if the alignment restrictions
are met otherwise will redirect through the ARC. This
property will not allow a request to fail.
There is also a module parameter zfs_dio_enabled that can be used to
force all reads and writes through the ARC. By setting this module
parameter to 0, it mimics as if the direct dataset property is set to
disabled.
Reviewed-by: Brian Behlendorf <behlendorf@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Co-authored-by: Mark Maybee <mark.maybee@delphix.com>
Co-authored-by: Matt Macy <mmacy@FreeBSD.org>
Co-authored-by: Brian Behlendorf <behlendorf@llnl.gov>
Closes#10018
1) Make mmap flushes synchronous. Linux may skip flushing dirty pages
already in writeback unless data-integrity sync is requested.
2) Change zfs_putpage to use TXG_WAIT. Otherwise dirty pages may be
skipped due to DMU pushing back on TX assign.
3) Add missing mmap flush when doing block cloning.
4) While here, pass errors from putpage to writepage/writepages.
This change fixes corruption edge cases, but unfortunately adds
synchronous ZIL flushes for dirty mmap pages to llseek and bclone
operations. It may be possible to avoid these sync writes later
but would need more tricky refactoring of the writeback code.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Robert Evans <evansr@google.com>
Closes#15933Closes#16019
Using the filemap_splice_read function for the splice_read handler was
leading to occasional data corruption under certain circumstances. Favor
using copy_splice_read instead, which does not demonstrate the same
erroneous behavior under the tested failure cases.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15164
The generic_file_splice_read function was removed in Linux 6.5 in favor
of filemap_splice_read. Add an autoconf test for filemap_splice_read and
use it if it is found as the handler for .splice_read in the
file_operations struct. Additionally, ITER_PIPE was removed in 6.5. This
change removes the ITER_* macros that OpenZFS doesn't use from being
tested in config/kernel-vfs-iov_iter.m4. The removal of ITER_PIPE was
causing the test to fail, which also affected the code responsible for
setting the .splice_read handler, above. That behavior caused run-time
panics on Linux 6.5.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15155
An iov_iter_type() function to access the "type" member of the struct
iov_iter was added at one point. Move the conditional logic to decide
which method to use for accessing it into a macro and simplify the
zpl_uio_init code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15100
The iov_iter->iov member is now iov_iter->__iov and must be accessed via
the accessor function iter_iov(). Create a wrapper that is conditionally
compiled to use the access method appropriate for the target kernel
version.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#15100
Redhat have backported copy_file_range and clone_file_range to the EL7
kernel using an "extended file operations" wrapper structure. This
connects all that up to let cloning work there too.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kay Pedersen <mail@mkwg.de>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-By: OpenDrives Inc.
Sponsored-By: Klara Inc.
Closes#15050
Prior to Linux 4.5, the FICLONE etc ioctls were specific to BTRFS, and
were implemented as regular filesystem-specific ioctls. This implements
those ioctls directly in OpenZFS, allowing cloning to work on older
kernels.
There's no need to gate these behind version checks; on later kernels
Linux will simply never deliver these ioctls, instead calling the
approprate VFS op.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kay Pedersen <mail@mkwg.de>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-By: OpenDrives Inc.
Sponsored-By: Klara Inc.
Closes#15050
This implements the Linux VFS ops required to service the file
copy/clone APIs:
.copy_file_range (4.5+)
.clone_file_range (4.5-4.19)
.dedupe_file_range (4.5-4.19)
.remap_file_range (4.20+)
Note that dedupe_file_range() and remap_file_range(REMAP_FILE_DEDUP) are
hooked up here, but are not implemented yet.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kay Pedersen <mail@mkwg.de>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-By: OpenDrives Inc.
Sponsored-By: Klara Inc.
Closes#15050
Linux kernel 6.3 changed a bunch of APIs to use the dedicated idmap
type for mounts (struct mnt_idmap), we need to detect these changes
and make zfs work with the new APIs.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14682
The type def of writepage_t in kernel 6.3 is changed to take
struct folio* as the first argument. We need to detect this
change and pass correct function to write_cache_pages().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14699
When a page is faulted in for memory mapped I/O the page lock
may be dropped before it has been read and marked up to date.
If a buffered read encounters such a page in mappedread() it
must wait until the page has been updated. Failure to do so
will result in a panic on debug builds and incorrect data on
production builds.
The critical part of this change is in mappedread() where pages
which are not up to date are now handled. Additionally, it
includes the following simplifications.
- zfs_getpage() and zfs_fillpage() could be passed an array of
pages. This could be more efficient if it was used but in
practice only a single page was ever provided. These
interfaces were simplified to acknowledge that.
- update_pages() was modified to correctly set the PG_error bit
on a page when it cannot be read by dmu_read().
- Setting PG_error and PG_uptodate was moved to zfs_fillpage()
from zpl_readpage_common(). This is consistent with the
handling in update_pages() and mappedread().
- Minor additional refactoring to comments and variable
declarations to improve readability.
- Add a test case to exercise concurrent buffered, direct,
and mmap IO to the same file.
- Reduce the mmap_sync test case default run time.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13608Closes#14498
As of the 4.13 kernel filemap_range_has_page() can be used to
check if there is a page mapped in a given file range. When
available this interface should be used which eliminates the
need for the zp->z_is_mapped boolean.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14493
Linux 5.17 commit torvalds/linux@5dfbfe71e enables "the idmapping
infrastructure to support idmapped mounts of filesystems mounted
with an idmapping". Update the OpenZFS accordingly to improve the
idmapped mount support.
This pull request contains the following changes:
- xattr setter functions are fixed to take mnt_ns argument. Without
this, cp -p would fail for an idmapped mount in a user namespace.
- idmap_util is enhanced/fixed for its use in a user ns context.
- One test case added to test idmapped mount in a user ns.
Reviewed-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14097
Adds support for idmapped mounts. Supported as of Linux 5.12 this
functionality allows user and group IDs to be remapped without changing
their state on disk. This can be useful for portable home directories
and a variety of container related use cases.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#12923Closes#13671
The zpl_fadvise() function was recently added and was not included
in the initial patch. Update it accordingly.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13831
Replace ZFS_ENTER and ZFS_VERIFY_ZP, which have hidden returns, with
functions that return error code. The reason we want to do this is
because hidden returns are not obvious and had caused some missing fail
path unwinding.
This patch changes the common, linux, and freebsd parts. Also fixes
fail path unwinding in zfs_fsync, zpl_fsync, zpl_xattr_{list,get,set}, and
zfs_lookup().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes#13831
The purpose of this PR is to accepts fadvise ioctl from userland
to do read-ahead by demand.
It could dramatically improve sequential read performance especially
when primarycache is set to metadata or zfs_prefetch_disable is 1.
If the file is mmaped, generic_fadvise is also called for page cache
read-ahead besides dmu_prefetch.
Only POSIX_FADV_WILLNEED and POSIX_FADV_SEQUENTIAL are supported in
this PR currently.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Finix Yan <yancw@info2soft.com>
Closes#13694
As of the Linux 5.19 kernel the readpage() address space operation
has been replaced by read_folio().
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
Page writebacks with WB_SYNC_NONE can take several seconds to complete
since they wait for the transaction group to close before being
committed. This is usually not a problem since the caller does not
need to wait. However, if we're simultaneously doing a writeback
with WB_SYNC_ALL (e.g via msync), the latter can block for several
seconds (up to zfs_txg_timeout) due to the active WB_SYNC_NONE
writeback since it needs to wait for the transaction to complete
and the PG_writeback bit to be cleared.
This commit deals with 2 cases:
- No page writeback is active. A WB_SYNC_ALL page writeback starts
and even completes. But when it's about to check if the PG_writeback
bit has been cleared, another writeback with WB_SYNC_NONE starts.
The sync page writeback ends up waiting for the non-sync page
writeback to complete.
- A page writeback with WB_SYNC_NONE is already active when a
WB_SYNC_ALL writeback starts. The WB_SYNC_ALL writeback ends up
waiting for the WB_SYNC_NONE writeback.
The fix works by carefully keeping track of active sync/non-sync
writebacks and committing when beneficial.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Shaan Nobee <sniper111@gmail.com>
Closes#12662Closes#12790
When using a Linux kernel which predates the iov_iter interface the
O_APPEND flag should be applied in zpl_aio_write() via the call to
generic_write_checks(). The updated pos variable was incorrectly
ignored resulting in the current offset being used.
This issue should only realistically impact the RHEL/CentOS 7.x
kernels which are based on Linux 3.10.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13370Closes#13377
It turns out, no, in fact, ZERO_RANGE and PUNCH_HOLE do
have differing semantics in some ways - in particular,
one requires KEEP_SIZE, and the other does not.
Also added a zero-range test to catch this, corrected a flaw
that made the punch-hole test succeed vacuously, and a typo
in file_write.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#13329Closes#13338
->readpages was removed and replaced by ->readahead. Define
zpl_readahead for kernels that don't have ->readpages.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Riccardo Schirone <rschirone91@gmail.com>
Closes#13278
ZFS allows to update and retrieve additional file level attributes for
FreeBSD. This commit allows additional file level attributes to be
updated and retrieved for Linux. These include the flags stored in the
upper half of z_pflags only.
Two new IOCTLs have been added for this purpose. ZFS_IOC_GETDOSFLAGS
can be used to retrieve the attributes, while ZFS_IOC_SETDOSFLAGS can
be used to update the attributes.
Attributes that are allowed to be updated include ZFS_IMMUTABLE,
ZFS_APPENDONLY, ZFS_NOUNLINK, ZFS_ARCHIVE, ZFS_NODUMP, ZFS_SYSTEM,
ZFS_HIDDEN, ZFS_READONLY, ZFS_REPARSE, ZFS_OFFLINE and ZFS_SPARSE.
Flags can be or'd together while calling ZFS_IOC_SETDOSFLAGS.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes#13118
69 CSTYLED BEGINs remain, appx. 30 of which can be removed if cstyle(1)
had a useful policy regarding
CALL(ARG1,
ARG2,
ARG3);
above 2 lines. As it stands, it spits out *both*
sysctl_os.c: 385: continuation line should be indented by 4 spaces
sysctl_os.c: 385: indent by spaces instead of tabs
which is very cool
Another >10 could be fixed by removing "ulong" &al. handling.
I don't foresee anyone actually using it intentionally
(does it even exist in modern headers? why did it in the first place?).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12993
For us, I think it's always just FALLOC_FL_PUNCH_HOLE with a fake
mustache on.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12975
Evaluated every variable that lives in .data (and globals in .rodata)
in the kernel modules, and constified/eliminated/localised them
appropriately. This means that all read-only data is now actually
read-only data, and, if possible, at file scope. A lot of previously-
global-symbols became inlinable (and inlined!) constants. Probably
not in a big Wowee Performance Moment, but hey.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12899
Provide access to file generation number on Linux.
Add test coverage.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes#12856
The iov_iter->type member was renamed iov_iter->iter_type. However,
while looking into this, realized that in 2018 a iov_iter_type(*iov)
accessor function was introduced. So if that is present, use it,
otherwise fall back to trying the existing behavior of directly
accessing type from iov_iter.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
Kernel 5.14 introduced a change where set_page_dirty of
struct address_space_operations is no longer implicitly set to
__set_page_dirty_buffers(), which ended up resulting in a NULL
pointer deref in the kernel when it is attempted to be called.
This change sets .set_page_dirty in the structure to
__set_page_dirty_nobuffers(), which was introduced with the
related patch set. The breaking change was introduce in commit
0af573780b0b13fceb7fabd49dc1b073cee9a507 to torvalds/linux.git.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12427
* zio: avoid callback typecasting
* zil: avoid zil_itxg_clean() callback typecasting
* zpl: decouple zpl_readpage() into two separate callbacks
* nvpair: explicitly declare callbacks for xdr_array()
* linux/zfs_nvops: don't use external iput() as a callback
* zcp_synctask: don't use fnvlist_free() as a callback
* zvol: don't use ops->zv_free() as a callback for taskq_dispatch()
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Closes#12260
The additional iter advance is incorrect, as copy_from_iter() has
already done the right thing. This will result in the following
warning being printed to the console as of the 5.12 kernel.
Attempted to advance past end of bvec iter
This change should have been included with #11378 when a
similar change was made on the read side.
Suggested-by: @siebenmann
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Issue #11378Closes#12041Closes#12155
Other (all?) Linux filesystems seem to return -EPERM instead of -EACCESS
when trying to set FS_APPEND_FL or FS_IMMUTABLE_FL without the
CAP_LINUX_IMMUTABLE capability. This was detected by generic/545 test
in the fstest suite.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Luis Henriques <henrix@camandro.org>
Closes#11791
In Linux 5.12, the filesystem API was modified to support ipmapped
mounts by adding a "struct user_namespace *" parameter to a number
functions and VFS handlers. This change adds the needed autoconf
macros to detect the new interfaces and updates the code appropriately.
This change does not add support for idmapped mounts, instead it
preserves the existing behavior by passing the initial user namespace
where needed. A subsequent commit will be required to add support
for idmapped mounted.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11712
In FreeBSD the struct uio was just a typedef to uio_t. In order to
extend this struct, outside of the definition for the struct uio, the
struct uio has been embedded inside of a uio_t struct.
Also renamed all the uio_* interfaces to be zfs_uio_* to make it clear
this is a ZFS interface.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11438
