Commit graph

1259 commits

Author SHA1 Message Date
Linus Torvalds
3bf6a9e36e virtio,vdpa,qemu_fw_cfg: features, cleanups, fixes
partial support for < MAX_ORDER - 1 granularity for virtio-mem
 driver_override for vdpa
 sysfs ABI documentation for vdpa
 multiqueue config support for mlx5 vdpa
 
 Misc fixes, cleanups.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes.

   - partial support for < MAX_ORDER - 1 granularity for virtio-mem

   - driver_override for vdpa

   - sysfs ABI documentation for vdpa

   - multiqueue config support for mlx5 vdpa

   - and misc fixes, cleanups"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits)
  vdpa/mlx5: Fix tracking of current number of VQs
  vdpa/mlx5: Fix is_index_valid() to refer to features
  vdpa: Protect vdpa reset with cf_mutex
  vdpa: Avoid taking cf_mutex lock on get status
  vdpa/vdpa_sim_net: Report max device capabilities
  vdpa: Use BIT_ULL for bit operations
  vdpa/vdpa_sim: Configure max supported virtqueues
  vdpa/mlx5: Report max device capabilities
  vdpa: Support reporting max device capabilities
  vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps()
  vdpa: Add support for returning device configuration information
  vdpa/mlx5: Support configuring max data virtqueue
  vdpa/mlx5: Fix config_attr_mask assignment
  vdpa: Allow to configure max data virtqueues
  vdpa: Read device configuration only if FEATURES_OK
  vdpa: Sync calls set/get config/status with cf_mutex
  vdpa/mlx5: Distribute RX virtqueues in RQT object
  vdpa: Provide interface to read driver features
  vdpa: clean up get_config_size ret value handling
  virtio_ring: mark ring unused on error
  ...
2022-01-18 10:05:48 +02:00
Michael S. Tsirkin
d9679d0013 virtio: wrap config->reset calls
This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-14 18:50:52 -05:00
Linus Torvalds
3acbdbf42e dax + libnvdimm for v5.17
- Simplify the dax_operations API
   - Eliminate bdev_dax_pgoff() in favor of the filesystem maintaining
     and applying a partition offset to all its DAX iomap operations.
   - Remove wrappers and device-mapper stacked callbacks for
     ->copy_from_iter() and ->copy_to_iter() in favor of moving
     block_device relative offset responsibility to the
     dax_direct_access() caller.
   - Remove the need for an @bdev in filesystem-DAX infrastructure
   - Remove unused uio helpers copy_from_iter_flushcache() and
     copy_mc_to_iter() as only the non-check_copy_size() versions are
     used for DAX.
 - Prepare XFS for the pending (next merge window) DAX+reflink support
 - Remove deprecated DEV_DAX_PMEM_COMPAT support
 - Cleanup a straggling misuse of the GUID api
 
 Tags offered after the branch was cut:
 Reviewed-by: Mike Snitzer <snitzer@redhat.com>
 Link: https://lore.kernel.org/r/Ydb/3P+8nvjCjYfO@redhat.com
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Merge tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull dax and libnvdimm updates from Dan Williams:
 "The bulk of this is a rework of the dax_operations API after
  discovering the obstacles it posed to the work-in-progress DAX+reflink
  support for XFS and other copy-on-write filesystem mechanics.

  Primarily the need to plumb a block_device through the API to handle
  partition offsets was a sticking point and Christoph untangled that
  dependency in addition to other cleanups to make landing the
  DAX+reflink support easier.

  The DAX_PMEM_COMPAT option has been around for 4 years and not only
  are distributions shipping userspace that understand the current
  configuration API, but some are not even bothering to turn this option
  on anymore, so it seems a good time to remove it per the deprecation
  schedule. Recall that this was added after the device-dax subsystem
  moved from /sys/class/dax to /sys/bus/dax for its sysfs organization.
  All recent functionality depends on /sys/bus/dax.

  Some other miscellaneous cleanups and reflink prep patches are
  included as well.

  Summary:

   - Simplify the dax_operations API:

      - Eliminate bdev_dax_pgoff() in favor of the filesystem
        maintaining and applying a partition offset to all its DAX iomap
        operations.

      - Remove wrappers and device-mapper stacked callbacks for
        ->copy_from_iter() and ->copy_to_iter() in favor of moving
        block_device relative offset responsibility to the
        dax_direct_access() caller.

      - Remove the need for an @bdev in filesystem-DAX infrastructure

      - Remove unused uio helpers copy_from_iter_flushcache() and
        copy_mc_to_iter() as only the non-check_copy_size() versions are
        used for DAX.

   - Prepare XFS for the pending (next merge window) DAX+reflink support

   - Remove deprecated DEV_DAX_PMEM_COMPAT support

   - Cleanup a straggling misuse of the GUID api"

* tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (38 commits)
  iomap: Fix error handling in iomap_zero_iter()
  ACPI: NFIT: Import GUID before use
  dax: remove the copy_from_iter and copy_to_iter methods
  dax: remove the DAXDEV_F_SYNC flag
  dax: simplify dax_synchronous and set_dax_synchronous
  uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()
  iomap: turn the byte variable in iomap_zero_iter into a ssize_t
  memremap: remove support for external pgmap refcounts
  fsdax: don't require CONFIG_BLOCK
  iomap: build the block based code conditionally
  dax: fix up some of the block device related ifdefs
  fsdax: shift partition offset handling into the file systems
  dax: return the partition offset from fs_dax_get_by_bdev
  iomap: add a IOMAP_DAX flag
  xfs: pass the mapping flags to xfs_bmbt_to_iomap
  xfs: use xfs_direct_write_iomap_ops for DAX zeroing
  xfs: move dax device handling into xfs_{alloc,free}_buftarg
  ext4: cleanup the dax handling in ext4_fill_super
  ext2: cleanup the dax handling in ext2_fill_super
  fsdax: decouple zeroing from the iomap buffered I/O code
  ...
2022-01-12 15:46:11 -08:00
Christoph Hellwig
7ac5360cd4 dax: remove the copy_from_iter and copy_to_iter methods
These methods indirect the actual DAX read/write path.  In the end pmem
uses magic flush and mc safe variants and fuse and dcssblk use plain ones
while device mapper picks redirects to the underlying device.

Add set_dax_nocache() and set_dax_nomc() APIs to control which copy
routines are used to remove indirect call from the read/write fast path
as well as a lot of boilerplate code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com> [virtiofs]
Link: https://lore.kernel.org/r/20211215084508.435401-5-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-18 08:04:53 -08:00
Christoph Hellwig
30c6828a17 dax: remove the DAXDEV_F_SYNC flag
Remove the DAXDEV_F_SYNC flag and thus the flags argument to alloc_dax and
just let the drivers call set_dax_synchronous directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20211215084508.435401-4-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-18 08:04:52 -08:00
Jeffle Xu
c3cb6f935e fuse: mark inode DONT_CACHE when per inode DAX hint changes
When the per inode DAX hint changes while the file is still *opened*, it
is quite complicated and maybe fragile to dynamically change the DAX
state.

Hence mark the inode and corresponding dentries as DONE_CACHE once the
per inode DAX hint changes, so that the inode instance will be evicted
and freed as soon as possible once the file is closed and the last
reference to the inode is put. And then when the file gets reopened next
time, the new instantiated inode will reflect the new DAX state.

In summary, when the per inode DAX hint changes for an *opened* file, the
DAX state of the file won't be updated until this file is closed and
reopened later.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14 11:09:37 +01:00
Jeffle Xu
2ee019fadc fuse: negotiate per inode DAX in FUSE_INIT
Among the FUSE_INIT phase, client shall advertise per inode DAX if it's
mounted with "dax=inode". Then server is aware that client is in per
inode DAX mode, and will construct per-inode DAX attribute accordingly.

Server shall also advertise support for per inode DAX. If server doesn't
support it while client is mounted with "dax=inode", client will
silently fallback to "dax=never" since "dax=inode" is advisory only.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14 11:09:37 +01:00
Jeffle Xu
93a497b9ad fuse: enable per inode DAX
DAX may be limited in some specific situation. When the number of usable
DAX windows is under watermark, the recalim routine will be triggered to
reclaim some DAX windows. It may have a negative impact on the
performance, since some processes may need to wait for DAX windows to be
recalimed and reused then. To mitigate the performance degradation, the
overall DAX window need to be expanded larger.

However, simply expanding the DAX window may not be a good deal in some
scenario. To maintain one DAX window chunk (i.e., 2MB in size), 32KB
(512 * 64 bytes) memory footprint will be consumed for page descriptors
inside guest, which is greater than the memory footprint if it uses
guest page cache when DAX disabled. Thus it'd better disable DAX for
those files smaller than 32KB, to reduce the demand for DAX window and
thus avoid the unworthy memory overhead.

Per inode DAX feature is introduced to address this issue, by offering a
finer grained control for dax to users, trying to achieve a balance
between performance and memory overhead.

The FUSE_ATTR_DAX flag in FUSE_LOOKUP reply is used to indicate whether
DAX should be enabled or not for corresponding file. Currently the state
whether DAX is enabled or not for the file is initialized only when
inode is instantiated.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14 11:09:37 +01:00
Jeffle Xu
780b1b959f fuse: make DAX mount option a tri-state
We add 'always', 'never', and 'inode' (default). '-o dax' continues to
operate the same which is equivalent to 'always'.

The following behavior is consistent with that on ext4/xfs:

 - The default behavior (when neither '-o dax' nor
   '-o dax=always|never|inode' option is specified) is equal to 'inode'
   mode, while 'dax=inode' won't be printed among the mount option list.

 - The 'inode' mode is only advisory. It will silently fallback to 'never'
   mode if fuse server doesn't support that.

Also noted that by the time of this commit, 'inode' mode is actually equal
to 'always' mode, before the per inode DAX flag is introduced in the
following patch.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14 11:09:36 +01:00
Jeffle Xu
cecd491641 fuse: add fuse_should_enable_dax() helper
This is in prep for following per inode DAX checking.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14 11:09:36 +01:00
Xie Yongji
e388164ea3 fuse: Pass correct lend value to filemap_write_and_wait_range()
The acceptable maximum value of lend parameter in
filemap_write_and_wait_range() is LLONG_MAX rather than -1. And there is
also some logic depending on LLONG_MAX check in write_cache_pages(). So
let's pass LLONG_MAX to filemap_write_and_wait_range() in
fuse_writeback_range() instead.

Fixes: 59bda8ecee ("fuse: flush extending writes")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Cc: <stable@vger.kernel.org> # v5.15
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-07 15:20:16 +01:00
Christoph Hellwig
fb08a1908c dax: simplify the dax_device <-> gendisk association
Replace the dax_host_hash with an xarray indexed by the pointer value
of the gendisk, and require explicitly calls from the block drivers that
want to associate their gendisk with a dax_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-5-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04 08:58:51 -08:00
Christoph Hellwig
afd586f0d0 dax: remove CONFIG_DAX_DRIVER
CONFIG_DAX_DRIVER only selects CONFIG_DAX now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20211129102203.2243509-4-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-12-04 08:58:51 -08:00
Vivek Goyal
3e2b6fdbdc fuse: send security context of inode on file
When a new inode is created, send its security context to server along with
creation request (FUSE_CREAT, FUSE_MKNOD, FUSE_MKDIR and FUSE_SYMLINK).
This gives server an opportunity to create new file and set security
context (possibly atomically).  In all the configurations it might not be
possible to set context atomically.

Like nfs and ceph, use security_dentry_init_security() to dermine security
context of inode and send it with create, mkdir, mknod, and symlink
requests.

Following is the information sent to server.

fuse_sectx_header, fuse_secctx, xattr_name, security_context

 - struct fuse_secctx_header
   This contains total number of security contexts being sent and total
   size of all the security contexts (including size of
   fuse_secctx_header).

 - struct fuse_secctx
   This contains size of security context which follows this structure.
   There is one fuse_secctx instance per security context.

 - xattr name string
   This string represents name of xattr which should be used while setting
   security context.

 - security context
   This is the actual security context whose size is specified in
   fuse_secctx struct.

Also add the FUSE_SECURITY_CTX flag for the `flags` field of the
fuse_init_out struct.  When this flag is set the kernel will append the
security context for a newly created inode to the request (create, mkdir,
mknod, and symlink).  The server is responsible for ensuring that the inode
appears atomically (preferrably) with the requested security context.

For example, If the server is using SELinux and backed by a "real" linux
file system that supports extended attributes it can write the security
context value to /proc/thread-self/attr/fscreate before making the syscall
to create the inode.

This patch is based on patch from Chirantan Ekbote <chirantan@chromium.org>

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-25 14:05:18 +01:00
Miklos Szeredi
473441720c fuse: release pipe buf after last use
Checking buf->flags should be done before the pipe_buf_release() is called
on the pipe buffer, since releasing the buffer might modify the flags.

This is exactly what page_cache_pipe_buf_release() does, and which results
in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was
trying to fix.

Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Fixes: 712a951025 ("fuse: fix page stealing")
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-25 14:05:18 +01:00
Miklos Szeredi
53db28933e fuse: extend init flags
FUSE_INIT flags are close to running out, so add another 32bits worth of
space.

Add FUSE_INIT_EXT flag to the old flags field in fuse_init_in.  If this
flag is set, then fuse_init_in is extended by 48bytes, in which a flags_hi
field is allocated to contain the high 32bits of the flags.

A flags_hi field is also added to fuse_init_out, allocated out of the
remaining unused fields.

Known userspace implementations of the fuse protocol have been checked to
accept the extended FUSE_INIT request, but this might cause problems with
other implementations.  If that happens to be the case, the protocol
negotiation will have to be extended with an extra initialization request
roundtrip.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-25 14:05:18 +01:00
Linus Torvalds
cdd39b0539 fuse update for 5.16
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Merge tag 'fuse-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fix a possible of deadlock in case inode writeback is in progress
   during dentry reclaim

 - Fix a crash in case of page stealing

 - Selectively invalidate cached attributes, possibly improving
   performance

 - Allow filesystems to disable data flushing from ->flush()

 - Misc fixes and cleanups

* tag 'fuse-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (23 commits)
  fuse: fix page stealing
  virtiofs: use strscpy for copying the queue name
  fuse: add FOPEN_NOFLUSH
  fuse: only update necessary attributes
  fuse: take cache_mask into account in getattr
  fuse: add cache_mask
  fuse: move reverting attributes to fuse_change_attributes()
  fuse: simplify local variables holding writeback cache state
  fuse: cleanup code conditional on fc->writeback_cache
  fuse: fix attr version comparison in fuse_read_update_size()
  fuse: always invalidate attributes after writes
  fuse: rename fuse_write_update_size()
  fuse: don't bump attr_version in cached write
  fuse: selective attribute invalidation
  fuse: don't increment nlink in link()
  fuse: decrement nlink on overwriting rename
  fuse: simplify __fuse_write_file_get()
  fuse: move fuse_invalidate_attr() into fuse_update_ctime()
  fuse: delete redundant code
  fuse: use kmap_local_page()
  ...
2021-11-09 10:46:32 -08:00
Linus Torvalds
c03098d4b9 gfs2: Fix mmap + page fault deadlocks
Functions gfs2_file_read_iter and gfs2_file_write_iter are both
 accessing the user buffer to write to or read from while holding the
 inode glock.  In the most basic scenario, that buffer will not be
 resident and it will be mapped to the same file.  Accessing the buffer
 will trigger a page fault, and gfs2 will deadlock trying to take the
 same inode glock again while trying to handle that fault.
 
 Fix that and similar, more complex scenarios by disabling page faults
 while accessing user buffers.  To make this work, introduce a small
 amount of new infrastructure and fix some bugs that didn't trigger so
 far, with page faults enabled.
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Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher:
 "Functions gfs2_file_read_iter and gfs2_file_write_iter are both
  accessing the user buffer to write to or read from while holding the
  inode glock.

  In the most basic deadlock scenario, that buffer will not be resident
  and it will be mapped to the same file. Accessing the buffer will
  trigger a page fault, and gfs2 will deadlock trying to take the same
  inode glock again while trying to handle that fault.

  Fix that and similar, more complex scenarios by disabling page faults
  while accessing user buffers. To make this work, introduce a small
  amount of new infrastructure and fix some bugs that didn't trigger so
  far, with page faults enabled"

* tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fix mmap + page fault deadlocks for direct I/O
  iov_iter: Introduce nofault flag to disable page faults
  gup: Introduce FOLL_NOFAULT flag to disable page faults
  iomap: Add done_before argument to iomap_dio_rw
  iomap: Support partial direct I/O on user copy failures
  iomap: Fix iomap_dio_rw return value for user copies
  gfs2: Fix mmap + page fault deadlocks for buffered I/O
  gfs2: Eliminate ip->i_gh
  gfs2: Move the inode glock locking to gfs2_file_buffered_write
  gfs2: Introduce flag for glock holder auto-demotion
  gfs2: Clean up function may_grant
  gfs2: Add wrapper for iomap_file_buffered_write
  iov_iter: Introduce fault_in_iov_iter_writeable
  iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
  gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
  powerpc/kvm: Fix kvm_use_magic_page
  iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value
2021-11-02 12:25:03 -07:00
Miklos Szeredi
712a951025 fuse: fix page stealing
It is possible to trigger a crash by splicing anon pipe bufs to the fuse
device.

The reason for this is that anon_pipe_buf_release() will reuse buf->page if
the refcount is 1, but that page might have already been stolen and its
flags modified (e.g. PG_lru added).

This happens in the unlikely case of fuse_dev_splice_write() getting around
to calling pipe_buf_release() after a page has been stolen, added to the
page cache and removed from the page cache.

Fix by calling pipe_buf_release() right after the page was inserted into
the page cache.  In this case the page has an elevated refcount so any
release function will know that the page isn't reusable.

Reported-by: Frank Dinoff <fdinoff@google.com>
Link: https://lore.kernel.org/r/CAAmZXrsGg2xsP1CK+cbuEMumtrqdvD-NKnWzhNcvn71RV3c1yw@mail.gmail.com/
Fixes: dd3bb14f44 ("fuse: support splice() writing to fuse device")
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-02 11:10:37 +01:00
Miklos Szeredi
7c594bbd2d virtiofs: use strscpy for copying the queue name
Always null terminate fsvq->name.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: b43b7e81eb ("virtiofs: provide a helper function for virtqueue initialization")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-11-02 11:08:19 +01:00
Linus Torvalds
b6773cdb0e for-5.16/ki_complete-2021-10-29
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Merge tag 'for-5.16/ki_complete-2021-10-29' of git://git.kernel.dk/linux-block

Pull kiocb->ki_complete() cleanup from Jens Axboe:
 "This removes the res2 argument from kiocb->ki_complete().

  Only the USB gadget code used it, everybody else passes 0. The USB
  guys checked the user gadget code they could find, and everybody just
  uses res as expected for the async interface"

* tag 'for-5.16/ki_complete-2021-10-29' of git://git.kernel.dk/linux-block:
  fs: get rid of the res2 iocb->ki_complete argument
  usb: remove res2 argument from gadget code completions
2021-11-01 10:17:11 -07:00
Amir Goldstein
a390ccb316 fuse: add FOPEN_NOFLUSH
Add flag returned by FUSE_OPEN and FUSE_CREATE requests to avoid flushing
data cache on close.

Different filesystems implement ->flush() is different ways:
 - Most disk filesystems do not implement ->flush() at all
 - Some network filesystem (e.g. nfs) flush local write cache of
   FMODE_WRITE file and send a "flush" command to server
 - Some network filesystem (e.g. cifs) flush local write cache of
   FMODE_WRITE file without sending an additional command to server

FUSE flushes local write cache of ANY file, even non FMODE_WRITE
and sends a "flush" command to server (if server implements it).

The FUSE implementation of ->flush() seems over agressive and
arbitrary and does not make a lot of sense when writeback caching is
disabled.

Instead of deciding on another arbitrary implementation that makes
sense, leave the choice of per-file flush behavior in the hands of
the server.

Link: https://lore.kernel.org/linux-fsdevel/CAJfpegspE8e6aKd47uZtSYX8Y-1e1FWS0VL0DH2Skb9gQP5RJQ@mail.gmail.com/
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 10:20:31 +02:00
Miklos Szeredi
c6c745b810 fuse: only update necessary attributes
fuse_update_attributes() refreshes metadata for internal use.

Each use needs a particular set of attributes to be refreshed, but
currently that cannot be expressed and all but atime are refreshed.

Add a mask argument, which lets fuse_update_get_attr() to decide based on
the cache_mask and the inval_mask whether a GETATTR call is needed or not.

Reported-by: Yongji Xie <xieyongji@bytedance.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:33 +02:00
Miklos Szeredi
ec85537519 fuse: take cache_mask into account in getattr
When deciding to send a GETATTR request take into account the cache mask
(which attributes are always valid).  The cache mask takes precedence over
the invalid mask.

This results in the GETATTR request not being sent unnecessarily.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:33 +02:00
Miklos Szeredi
4b52f059b5 fuse: add cache_mask
If writeback_cache is enabled, then the size, mtime and ctime attributes of
regular files are always valid in the kernel's cache.  They are retrieved
from userspace only when the inode is freshly looked up.

Add a more generic "cache_mask", that indicates which attributes are
currently valid in cache.

This patch doesn't change behavior.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:33 +02:00
Miklos Szeredi
04d82db0c5 fuse: move reverting attributes to fuse_change_attributes()
In case of writeback_cache fuse_fillattr() would revert the queried
attributes to the cached version.

Move this to fuse_change_attributes() in order to manage the writeback
logic in a central helper.  This will be necessary for patches that follow.

Only fuse_do_getattr() -> fuse_fillattr() uses the attributes after calling
fuse_change_attributes(), so this should not change behavior.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
c15016b7ae fuse: simplify local variables holding writeback cache state
There are two instances of "bool is_wb = fc->writeback_cache" where the
actual use mostly involves checking "is_wb && S_ISREG(inode->i_mode)".

Clean up these cases by storing the second condition in the local variable.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
20235b435a fuse: cleanup code conditional on fc->writeback_cache
It's safe to call file_update_time() if writeback cache is not enabled,
since S_NOCMTIME is set in this case.  This part is purely a cleanup.

__fuse_copy_file_range() also calls fuse_write_update_attr() only in the
writeback cache case.  This is inconsistent with other callers, where it's
called unconditionally.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
484ce65715 fuse: fix attr version comparison in fuse_read_update_size()
A READ request returning a short count is taken as indication of EOF, and
the cached file size is modified accordingly.

Fix the attribute version checking to allow for changes to fc->attr_version
on other inodes.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
d347739a0e fuse: always invalidate attributes after writes
Extend the fuse_write_update_attr() helper to invalidate cached attributes
after a write.

This has already been done in all cases except in fuse_notify_store(), so
this is mostly a cleanup.

fuse_direct_write_iter() calls fuse_direct_IO() which already calls
fuse_write_update_attr(), so don't repeat that again in the former.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
27ae449ba2 fuse: rename fuse_write_update_size()
This function already updates the attr_version in fuse_inode, regardless of
whether the size was changed or not.

Rename the helper to fuse_write_update_attr() to reflect the more generic
nature.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
8c56e03d2e fuse: don't bump attr_version in cached write
The attribute version in fuse_inode should be updated whenever the
attributes might have changed on the server.  In case of cached writes this
is not the case, so updating the attr_version is unnecessary and could
possibly affect performance.

Open code the remaining part of fuse_write_update_size().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
fa5eee57e3 fuse: selective attribute invalidation
Only invalidate attributes that the operation might have changed.

Introduce two constants for common combinations of changed attributes:

  FUSE_STATX_MODIFY: file contents are modified but not size

  FUSE_STATX_MODSIZE: size and/or file contents modified

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:32 +02:00
Miklos Szeredi
97f044f690 fuse: don't increment nlink in link()
The fuse_iget() call in create_new_entry() already updated the inode with
all the new attributes and incremented the attribute version.

Incrementing the nlink will result in the wrong count.  This wasn't noticed
because the attributes were invalidated right after this.

Updating ctime is still needed for the writeback case when the ctime is not
refreshed.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28 09:45:26 +02:00
Jens Axboe
6b19b766e8 fs: get rid of the res2 iocb->ki_complete argument
The second argument was only used by the USB gadget code, yet everyone
pays the overhead of passing a zero to be passed into aio, where it
ends up being part of the aio res2 value.

Now that everybody is passing in zero, kill off the extra argument.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-25 10:36:24 -06:00
Miklos Szeredi
cefd1b8327 fuse: decrement nlink on overwriting rename
Rename didn't decrement/clear nlink on overwritten target inode.

Create a common helper fuse_entry_unlinked() that handles this for unlink,
rmdir and rename.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:02 +02:00
Miklos Szeredi
84840efc3c fuse: simplify __fuse_write_file_get()
Use list_first_entry_or_null() instead of list_empty() + list_entry().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:02 +02:00
Miklos Szeredi
371e8fd029 fuse: move fuse_invalidate_attr() into fuse_update_ctime()
Logically it belongs there since attributes are invalidated due to the
updated ctime.  This is a cleanup and should not change behavior.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Peng Hao
b5d9758297 fuse: delete redundant code
'ia->io=io' has been set in fuse_io_alloc.

Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Peng Hao
5fe0fc9f1d fuse: use kmap_local_page()
Due to the introduction of kmap_local_*, the storage of slots used for
short-term mapping has changed from per-CPU to per-thread.  kmap_atomic()
disable preemption, while kmap_local_*() only disable migration.

There is no need to disable preemption in several kamp_atomic places used
in fuse.

Link: https://lwn.net/Articles/836144/
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Miklos Szeredi
bda9a71980 fuse: annotate lock in fuse_reverse_inval_entry()
Add missing inode lock annotatation; found by syzbot.

Reported-and-tested-by: syzbot+9f747458f5990eaa8d43@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Miklos Szeredi
36ea23374d fuse: write inode in fuse_vma_close() instead of fuse_release()
Fuse ->release() is otherwise asynchronous for the reason that it can
happen in contexts unrelated to close/munmap.

Inode is already written back from fuse_flush().  Add it to
fuse_vma_close() as well to make sure inode dirtying from mmaps also get
written out before the file is released.

Also add error handling.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Miklos Szeredi
5c791fe1e2 fuse: make sure reclaim doesn't write the inode
In writeback cache mode mtime/ctime updates are cached, and flushed to the
server using the ->write_inode() callback.

Closing the file will result in a dirty inode being immediately written,
but in other cases the inode can remain dirty after all references are
dropped.  This result in the inode being written back from reclaim, which
can deadlock on a regular allocation while the request is being served.

The usual mechanisms (GFP_NOFS/PF_MEMALLOC*) don't work for FUSE, because
serving a request involves unrelated userspace process(es).

Instead do the same as for dirty pages: make sure the inode is written
before the last reference is gone.

 - fallocate(2)/copy_file_range(2): these call file_update_time() or
   file_modified(), so flush the inode before returning from the call

 - unlink(2), link(2) and rename(2): these call fuse_update_ctime(), so
   flush the ctime directly from this helper

Reported-by: chenguanyou <chenguanyou@xiaomi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22 17:03:01 +02:00
Miklos Szeredi
964d32e512 fuse: clean up error exits in fuse_fill_super()
Instead of "goto err", return error directly, since there's no error
cleanup to do now.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21 10:01:39 +02:00
Miklos Szeredi
80019f1138 fuse: always initialize sb->s_fs_info
Syzkaller reports a null pointer dereference in fuse_test_super() that is
caused by sb->s_fs_info being NULL.

This is due to the fact that fuse_fill_super() is initializing s_fs_info,
which is too late, it's already on the fs_supers list.  The initialization
needs to be done in sget_fc() with the sb_lock held.

Move allocation of fuse_mount and fuse_conn from fuse_fill_super() into
fuse_get_tree().

After this ->kill_sb() will always be called with non-NULL ->s_fs_info,
hence fuse_mount_destroy() can drop the test for non-NULL "fm".

Reported-by: syzbot+74a15f02ccb51f398601@syzkaller.appspotmail.com
Fixes: 5d5b74aa9c ("fuse: allow sharing existing sb")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21 10:01:39 +02:00
Miklos Szeredi
c191cd07ee fuse: clean up fuse_mount destruction
1. call fuse_mount_destroy() for open coded variants

2. before deactivate_locked_super() don't need fuse_mount destruction since
that will now be done (if ->s_fs_info is not cleared)

3. rearrange fuse_mount setup in fuse_get_tree_submount() so that the
regular pattern can be used

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21 10:01:39 +02:00
Miklos Szeredi
a27c061a49 fuse: get rid of fuse_put_super()
The ->put_super callback is called from generic_shutdown_super() in case of
a fully initialized sb.  This is called from kill_***_super(), which is
called from ->kill_sb instances.

Fuse uses ->put_super to destroy the fs specific fuse_mount and drop the
reference to the fuse_conn, while it does the same on each error case
during sb setup.

This patch moves the destruction from fuse_put_super() to
fuse_mount_destroy(), called at the end of all ->kill_sb instances.  A
follup patch will clean up the error paths.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21 10:01:38 +02:00
Miklos Szeredi
d534d31d6a fuse: check s_root when destroying sb
Checking "fm" works because currently sb->s_fs_info is cleared on error
paths; however, sb->s_root is what generic_shutdown_super() checks to
determine whether the sb was fully initialized or not.

This change will allow cleanup of sb setup error paths.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-21 10:01:38 +02:00
Andreas Gruenbacher
a6294593e8 iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
Turn iov_iter_fault_in_readable into a function that returns the number
of bytes not faulted in, similar to copy_to_user, instead of returning a
non-zero value when any of the requested pages couldn't be faulted in.
This supports the existing users that require all pages to be faulted in
as well as new users that are happy if any pages can be faulted in.

Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make
sure this change doesn't silently break things.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-10-18 16:35:06 +02:00
Linus Torvalds
75b96f0ec5 fuse update for 5.15
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Merge tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Allow mounting an active fuse device. Previously the fuse device
   would always be mounted during initialization, and sharing a fuse
   superblock was only possible through mount or namespace cloning

 - Fix data flushing in syncfs (virtiofs only)

 - Fix data flushing in copy_file_range()

 - Fix a possible deadlock in atomic O_TRUNC

 - Misc fixes and cleanups

* tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: remove unused arg in fuse_write_file_get()
  fuse: wait for writepages in syncfs
  fuse: flush extending writes
  fuse: truncate pagecache on atomic_o_trunc
  fuse: allow sharing existing sb
  fuse: move fget() to fuse_get_tree()
  fuse: move option checking into fuse_fill_super()
  fuse: name fs_context consistently
  fuse: fix use after free in fuse_read_interrupt()
2021-09-07 12:18:29 -07:00