Use netfslib's read and write iteration helpers, allowing netfslib to take
over the management of the page cache for 9p files and to manage local disk
caching. In particular, this eliminates write_begin, write_end, writepage
and all mentions of struct page and struct folio from 9p.
Note that netfslib now offers the possibility of write-through caching if
that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
v9inode->netfs.flags in v9fs_set_netfs_context().
Note also this is untested as I can't get ganesha.nfsd to correctly parse
the config to turn on 9p support.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: v9fs@lists.linux.dev
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
Track the file position above which the server is not expected to have any
data (the "zero point") and preemptively assume that we can satisfy
requests by filling them with zeroes locally rather than attempting to
download them if they're over that line - even if we've written data back
to the server. Assume that any data that was written back above that
position is held in the local cache. Note that we have to split requests
that straddle the line.
Make use of this to optimise away some reads from the server. We need to
set the zero point in the following circumstances:
(1) When we see an extant remote inode and have no cache for it, we set
the zero_point to i_size.
(2) On local inode creation, we set zero_point to 0.
(3) On local truncation down, we reduce zero_point to the new i_size if
the new i_size is lower.
(4) On local truncation up, we don't change zero_point.
(5) On local modification, we don't change zero_point.
(6) On remote invalidation, we set zero_point to the new i_size.
(7) If stored data is discarded from the pagecache or culled from fscache,
we must set zero_point above that if the data also got written to the
server.
(8) If dirty data is written back to the server, but not fscache, we must
set zero_point above that.
(9) If a direct I/O write is made, set zero_point above that.
Assuming the above, any read from the server at or above the zero_point
position will return all zeroes.
The zero_point value can be stored in the cache, provided the above rules
are applied to it by any code that culls part of the local cache.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Provide a flag whereby a filesystem may request that cifs_perform_write()
perform write-through caching. This involves putting pages directly into
writeback rather than dirty and attaching them to a write operation as we
go.
Further, the writes being made are limited to the byte range being written
rather than whole folios being written. This can be used by cifs, for
example, to deal with strict byte-range locking.
This can't be used with content encryption as that may require expansion of
the write RPC beyond the write being made.
This doesn't affect writes via mmap - those are written back in the normal
way; similarly failed writethrough writes are marked dirty and left to
writeback to retry. Another option would be to simply invalidate them, but
the contents can be simultaneously accessed by read() and through mmap.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Make netfslib pass the maximum length to the ->prepare_write() op to tell
the cache how much it can expand the length of a write to. This allows a
write to the server at the end of a file to be limited to a few bytes
whilst writing an entire block to the cache (something required by direct
I/O).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Institute a netfs write helper, netfs_file_write_iter(), to be pointed at
by the network filesystem ->write_iter() call. Make it handled buffered
writes by calling the previously defined netfs_perform_write() to copy the
source data into the pagecache.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary. DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.
Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing. The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.
The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method. Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.
Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined. As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.
In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
netfs_read_folio() needs to handle partially-valid pages that are marked
dirty, but not uptodate in the event that someone tries to read a page was
used to cache data by a streaming write.
In such a case, make netfs_read_folio() set up a bvec iterator that points
to the parts of the folio that need filling and to a sink page for the data
that should be discarded and use that instead of i_pages as the iterator to
be written to.
This requires netfs_rreq_unlock_folios() to convert the page into a normal
dirty uptodate page, getting rid of the partial write record and bumping
the group pointer over to folio->private.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Provide a netfs write helper, netfs_perform_write() to buffer data to be
written in the pagecache and mark the modified folios dirty.
It will perform "streaming writes" for folios that aren't currently
resident, if possible, storing data in partially modified folios that are
marked dirty, but not uptodate. It will also tag pages as belonging to
fs-specific write groups if so directed by the filesystem.
This is derived from generic_perform_write(), but doesn't use
->write_begin() and ->write_end(), having that logic rolled in instead.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Dispatch one or more write reqeusts to process a writeback slice, where a
slice is tailored more to logical block divisions within the file (such as
crypto blocks, an object layout or cache granules) than the protocol RPC
maximum capacity.
The dispatch doesn't happen until throttling allows, at which point the
entire writeback slice is processed and queued. A slice may be written to
multiple destinations (one or more servers and the local cache) and the
writes to each destination might be split up along different lines.
The writeback slice holds the required folios pinned. An iov_iter is
provided in netfs_write_request that describes the buffer to be used. This
may be part of the pagecache, may have auxiliary padding pages attached or
may be a bounce buffer resulting from crypto or compression. Consequently,
the filesystem must not twiddle the folio markings directly.
The following API is available to the filesystem:
(1) The ->create_write_requests() method is called to ask the filesystem
to create the requests it needs. This is passed the writeback slice
to be processed.
(2) The filesystem should then call netfs_create_write_request() to create
the requests it needs.
(3) Once a request is initialised, netfs_queue_write_request() can be
called to dispatch it asynchronously, if not completed immediately.
(4) netfs_write_request_completed() should be called to note the
completion of a request.
(5) netfs_get_write_request() and netfs_put_write_request() are provided
to refcount a request. These take constants from the netfs_wreq_trace
enum for logging into ftrace.
(6) The ->free_write_request is method is called to ask the filesystem to
clean up a request.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Prepare to use folio->private to hold information write grouping and
streaming write. These are implemented in the same commit as they both
make use of folio->private and will be both checked at the same time in
several places.
"Write grouping" involves ordering the writeback of groups of writes, such
as is needed for ceph snaps. A group is represented by a
filesystem-supplied object which must contain a netfs_group struct. This
contains just a refcount and a pointer to a destructor.
"Streaming write" is the storage of data in folios that are marked dirty,
but not uptodate, to avoid unnecessary reads of data. This is represented
by a netfs_folio struct. This contains the offset and length of the
modified region plus the otherwise displaced write grouping pointer.
The way folio->private is multiplexed is:
(1) If private is NULL then neither is in operation on a dirty folio.
(2) If private is set, with bit 0 clear, then this points to a group.
(3) If private is set, with bit 0 set, then this points to a netfs_folio
struct (with bit 0 AND'ed out).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Modify the netfs_io_request struct to act as a point around which writes
can be coordinated. It represents and pins a range of pages that need
writing and a list of regions of dirty data in that range of pages.
If RMW is required, the original data can be downloaded into the bounce
buffer, decrypted if necessary, the modifications made, then the modified
data can be reencrypted/recompressed and sent back to the server.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Add a function to work out how much of an ITER_BVEC or ITER_XARRAY iterator
we can use in a pagecount-limited and size-limited span. This will be
used, for example, to limit the number of segments in a subrequest to the
maximum number of elements that an RDMA transfer can handle.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Provide tools to create a buffer in an xarray, with a function to add new
folios with a mark. This will be used to create bounce buffer and can be
used more easily to create a list of folios the span of which would require
more than a page's worth of bio_vec structs.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Add a bvec array pointer and an iterator to netfs_io_request for either
holding a copy of a DIO iterator or a list of all the bits of buffer
pointed to by a DIO iterator.
There are two problems: Firstly, if an iovec-class iov_iter is passed to
->read_iter() or ->write_iter(), this cannot be passed directly to
kernel_sendmsg() or kernel_recvmsg() as that may cause locking recursion if
a fault is generated, so we need to keep track of the pages involved
separately.
Secondly, if the I/O is asynchronous, we must copy the iov_iter describing
the buffer before returning to the caller as it may be immediately
deallocated.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Add three iov_iter structs:
(1) Add an iov_iter (->iter) to the I/O request to describe the
unencrypted-side buffer.
(2) Add an iov_iter (->io_iter) to the I/O request to describe the
encrypted-side I/O buffer. This may be a different size to the buffer
in (1).
(3) Add an iov_iter (->io_iter) to the I/O subrequest to describe the part
of the I/O buffer for that subrequest.
This will allow future patches to point to a bounce buffer instead for
purposes of handling oversize writes, decryption (where we want to save the
encrypted data to the cache) and decompression.
These iov_iters persist for the lifetime of the (sub)request, and so can be
accessed multiple times without worrying about them being deallocated upon
return to the caller.
The network filesystem must appropriately advance the iterator before
terminating the request.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
AFS currently uses folio->private to store the range of bytes within a
folio that have been modified - the idea being that if we have, say, a 2MiB
folio and someone writes a single byte, we only have to write back that
single page and not the whole 2MiB folio - thereby saving on network
bandwidth.
Remove this, at least for now, and accept the extra network load (which
doesn't matter in the common case of writing a whole file at a time from
beginning to end).
This makes folio->private available for netfslib to use.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have dirty
pages on the netfs inode in the pagecache such that VM writeback will be
able to reach it.
Whilst we're at it, switch the parameters of netfs_unpin_writeback() to
match ->write_inode() so that it can be used for that directly.
Note that this mechanism could be more generically useful than that for
network filesystems. Quite often they have to keep around other resources
(e.g. authentication tokens or network connections) until the writeback is
complete.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
There's a problem with dependencies between netfslib and fscache as each
wants to access some functions of the other. Deal with this by moving
fs/fscache/* into fs/netfs/ and renaming those files to begin with
"fscache-".
For the moment, the moved files are changed as little as possible and an
fscache module is still built. A subsequent patch will integrate them.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Christian Brauner <christian@brauner.io>
cc: linux-fsdevel@vger.kernel.org
cc: linux-cachefs@redhat.com
Pull x86 fixes from Ingo Molnar:
- Fix a secondary CPUs enumeration regression caused by creative MADT
APIC table entries on certain systems.
- Fix a race in the NOP-patcher that can spuriously trigger crashes on
bootup.
- Fix a bootup failure regression caused by the parallel bringup code,
caused by firmware inconsistency between the APIC initialization
states of the boot and secondary CPUs, on certain systems.
* tag 'x86-urgent-2023-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/acpi: Handle bogus MADT APIC tables gracefully
x86/alternatives: Disable interrupts and sync when optimizing NOPs in place
x86/alternatives: Sync core before enabling interrupts
x86/smpboot/64: Handle X2APIC BIOS inconsistency gracefully
Pull SCSI fixes from James Bottomley:
"Four small fixes, three in drivers with the core one adding a batch
indicator (for drivers which use it) to the error handler"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufs: core: Let the sq_lock protect sq_tail_slot access
scsi: ufs: qcom: Return ufs_qcom_clk_scale_*() errors in ufs_qcom_clk_scale_notify()
scsi: core: Always send batch on reset or error handling command
scsi: bnx2fc: Fix skb double free in bnx2fc_rcv()
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some small bugfixes and new device ids for USB and
Thunderbolt drivers for 6.7-rc7. Included in here are:
- new usb-serial device ids
- thunderbolt driver fixes
- typec driver fix
- usb-storage driver quirk added
- fotg210 driver fix
All of these have been in linux-next with no reported issues"
* tag 'usb-6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: serial: option: add Quectel EG912Y module support
USB: serial: ftdi_sio: update Actisense PIDs constant names
usb: fotg210-hcd: delete an incorrect bounds test
usb-storage: Add quirk for incorrect WP on Kingston DT Ultimate 3.0 G3
usb: typec: ucsi: fix gpio-based orientation detection
net: usb: ax88179_178a: avoid failed operations when device is disconnected
USB: serial: option: add Quectel RM500Q R13 firmware support
USB: serial: option: add Foxconn T99W265 with new baseline
thunderbolt: Fix minimum allocated USB 3.x and PCIe bandwidth
thunderbolt: Fix memory leak in margining_port_remove()
Pull char / misc driver fixes from Greg KH:
"Here are a small number of various driver fixes for 6.7-rc7 that
normally come through the char-misc tree, and one debugfs fix as well.
Included in here are:
- iio and hid sensor driver fixes for a number of small things
- interconnect driver fixes
- brcm_nvmem driver fixes
- debugfs fix for previous fix
- guard() definition in device.h so that many subsystems can start
using it for 6.8-rc1 (requested by Dan Williams to make future
merges easier)
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (21 commits)
debugfs: initialize cancellations earlier
Revert "iio: hid-sensor-als: Add light color temperature support"
Revert "iio: hid-sensor-als: Add light chromaticity support"
nvmem: brcm_nvram: store a copy of NVRAM content
dt-bindings: nvmem: mxs-ocotp: Document fsl,ocotp
driver core: Add a guard() definition for the device_lock()
interconnect: qcom: icc-rpm: Fix peak rate calculation
iio: adc: MCP3564: fix hardware identification logic
iio: adc: MCP3564: fix calib_bias and calib_scale range checks
iio: adc: meson: add separate config for axg SoC family
iio: adc: imx93: add four channels for imx93 adc
iio: adc: ti_am335x_adc: Fix return value check of tiadc_request_dma()
interconnect: qcom: sm8250: Enable sync_state
iio: triggered-buffer: prevent possible freeing of wrong buffer
iio: imu: inv_mpu6050: fix an error code problem in inv_mpu6050_read_raw
iio: imu: adis16475: use bit numbers in assign_bit()
iio: imu: adis16475: add spi_device_id table
iio: tmag5273: fix temperature offset
interconnect: Treat xlate() returning NULL node as an error
iio: common: ms_sensors: ms_sensors_i2c: fix humidity conversion time table
...
Pull input updates from Dmitry Torokhov:
- a quirk to AT keyboard driver to skip issuing "GET ID" command when
8042 is in translated mode and the device is a laptop/portable,
because the "GET ID" command makes a bunch of recent laptops unhappy
- a quirk to i8042 to disable multiplexed mode on Acer P459-G2-M which
causes issues on resume
- psmouse will activate native RMI4 protocol support for touchpad on
ThinkPad L14 G1
- addition of Razer Wolverine V2 ID to xpad gamepad driver
- mapping for airplane mode button in soc_button_array driver for
TUXEDO laptops
- improved error handling in ipaq-micro-keys driver
- amimouse being prepared for platform remove callback returning void
* tag 'input-for-v6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: soc_button_array - add mapping for airplane mode button
Input: xpad - add Razer Wolverine V2 support
Input: ipaq-micro-keys - add error handling for devm_kmemdup
Input: amimouse - convert to platform remove callback returning void
Input: i8042 - add nomux quirk for Acer P459-G2-M
Input: atkbd - skip ATKBD_CMD_GETID in translated mode
Input: psmouse - enable Synaptics InterTouch for ThinkPad L14 G1
This add a mapping for the airplane mode button on the TUXEDO Pulse Gen3.
While it is physically a key it behaves more like a switch, sending a key
down on first press and a key up on 2nd press. Therefor the switch event
is used here. Besides this behaviour it uses the HID usage-id 0xc6
(Wireless Radio Button) and not 0xc8 (Wireless Radio Slider Switch), but
since neither 0xc6 nor 0xc8 are currently implemented at all in
soc_button_array this not to standard behaviour is not put behind a quirk
for the moment.
Signed-off-by: Christoffer Sandberg <cs@tuxedo.de>
Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Link: https://lore.kernel.org/r/20231215171718.80229-1-wse@tuxedocomputers.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Pull block fixes from Jens Axboe:
"Just an NVMe pull request this time, with a fix for bad sleeping
context, and a revert of a patch that caused some trouble"
* tag 'block-6.7-2023-12-22' of git://git.kernel.dk/linux:
nvme-pci: fix sleeping function called from interrupt context
Revert "nvme-fc: fix race between error recovery and creating association"
Pull kvm fixes from Paolo Bonzini:
"RISC-V:
- Fix a race condition in updating external interrupt for
trap-n-emulated IMSIC swfile
- Fix print_reg defaults in get-reg-list selftest
ARM:
- Ensure a vCPU's redistributor is unregistered from the MMIO bus if
vCPU creation fails
- Fix building KVM selftests for arm64 from the top-level Makefile
x86:
- Fix breakage for SEV-ES guests that use XSAVES
Selftests:
- Fix bad use of strcat(), by not using strcat() at all"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: SEV: Do not intercept accesses to MSR_IA32_XSS for SEV-ES guests
KVM: selftests: Fix dynamic generation of configuration names
RISCV: KVM: update external interrupt atomically for IMSIC swfile
KVM: riscv: selftests: Fix get-reg-list print_reg defaults
KVM: selftests: Ensure sysreg-defs.h is generated at the expected path
KVM: Convert comment into an assertion in kvm_io_bus_register_dev()
KVM: arm64: vgic: Ensure that slots_lock is held in vgic_register_all_redist_iodevs()
KVM: arm64: vgic: Force vcpu vgic teardown on vcpu destroy
KVM: arm64: vgic: Add a non-locking primitive for kvm_vgic_vcpu_destroy()
KVM: arm64: vgic: Simplify kvm_vgic_destroy()
KVM/riscv fixes for 6.7, take #1
- Fix a race condition in updating external interrupt for
trap-n-emulated IMSIC swfile
- Fix print_reg defaults in get-reg-list selftest
