linux.git/fs/fuse, branch v5.10

Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2020-10-19T21:28:30+00:00

Pull fuse updates from Miklos Szeredi:

- Support directly accessing host page cache from virtiofs. This can
improve I/O performance for various workloads, as well as reducing
the memory requirement by eliminating double caching. Thanks to Vivek
Goyal for doing most of the work on this.

- Allow automatic submounting inside virtiofs. This allows unique
st_dev/ st_ino values to be assigned inside the guest to files
residing on different filesystems on the host. Thanks to Max Reitz
for the patches.

- Fix an old use after free bug found by Pradeep P V K.

* tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits)
virtiofs: calculate number of scatter-gather elements accurately
fuse: connection remove fix
fuse: implement crossmounts
fuse: Allow fuse_fill_super_common() for submounts
fuse: split fuse_mount off of fuse_conn
fuse: drop fuse_conn parameter where possible
fuse: store fuse_conn in fuse_req
fuse: add submount support to
fuse: fix page dereference after free
virtiofs: add logic to free up a memory range
virtiofs: maintain a list of busy elements
virtiofs: serialize truncate/punch_hole and dax fault path
virtiofs: define dax address space operations
virtiofs: add DAX mmap support
virtiofs: implement dax read/write operations
virtiofs: introduce setupmapping/removemapping commands
virtiofs: implement FUSE_INIT map_alignment field
virtiofs: keep a list of free dax memory ranges
virtiofs: add a mount option to enable dax
virtiofs: set up virtio_fs dax_device
...

virtiofs: calculate number of scatter-gather elements accurately

2020-10-14T12:16:22+00:00

virtiofs currently maps various buffers in scatter gather list and it looks
at number of pages (ap->pages) and assumes that same number of pages will
be used both for input and output (sg_count_fuse_req()), and calculates
total number of scatterlist elements accordingly.

But looks like this assumption is not valid in all the cases. For example,
Cai Qian reported that trinity, triggers warning with virtiofs sometimes.
A closer look revealed that if one calls ioctl(fd, 0x5a004000, buf), it
will trigger following warning.

WARN_ON(out_sgs + in_sgs != total_sgs)

In this case, total_sgs = 8, out_sgs=4, in_sgs=3. Number of pages is 2
(ap->pages), but out_sgs are using both the pages but in_sgs are using
only one page. In this case, fuse_do_ioctl() sets different size values
for input and output.

args->in_args[args->in_numargs - 1].size == 6656
args->out_args[args->out_numargs - 1].size == 4096

So current method of calculating how many scatter-gather list elements
will be used is not accurate. Make calculations more precise by parsing
size and ap->descs.

Reported-by: Qian Cai 
Signed-off-by: Vivek Goyal 
Link: https://lore.kernel.org/linux-fsdevel/5ea77e9f6cb8c2db43b09fbd4158ab2d8c066a0a.camel@redhat.com/
Reviewed-by: Stefan Hajnoczi 
Signed-off-by: Miklos Szeredi

Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

2020-10-13T19:12:44+00:00

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...

fuse: connection remove fix

2020-10-12T08:28:14+00:00

Re-add lost removal of fc from fuse_conn_list and the control filesystem.

Reported-by: kernel test robot 
Fixes: fcee216beb9c ("fuse: split fuse_mount off of fuse_conn")
Signed-off-by: Miklos Szeredi

fuse: implement crossmounts

2020-10-09T14:33:47+00:00

FUSE servers can indicate crossmount points by setting FUSE_ATTR_SUBMOUNT
in fuse_attr.flags.  The inode will then be marked as S_AUTOMOUNT, and the
.d_automount implementation creates a new submount at that location, so
that the submount gets a distinct st_dev value.

Note that all submounts get a distinct superblock and a distinct st_dev
value, so for virtio-fs, even if the same filesystem is mounted more than
once on the host, none of its mount points will have the same st_dev.  We
need distinct superblocks because the superblock points to the root node,
but the different host mounts may show different trees (e.g. due to
submounts in some of them, but not in others).

Right now, this behavior is only enabled when fuse_conn.auto_submounts is
set, which is the case only for virtio-fs.

Signed-off-by: Max Reitz 
Signed-off-by: Miklos Szeredi

bdi: invert BDI_CAP_NO_ACCT_WB

2020-09-24T19:43:39+00:00

Replace BDI_CAP_NO_ACCT_WB with a positive BDI_CAP_WRITEBACK_ACCT to
make the checks more obvious.  Also remove the pointless
bdi_cap_account_writeback wrapper that just obsfucates the check.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

bdi: initialize ->ra_pages and ->io_pages in bdi_init

2020-09-24T19:43:39+00:00

Set up a readahead size by default, as very few users have a good
reason to change it.  This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Acked-by: David Sterba  [btrfs]
Acked-by: Richard Weinberger  [ubifs, mtd]
Signed-off-by: Jens Axboe

fuse: Allow fuse_fill_super_common() for submounts

2020-09-18T13:17:41+00:00

Submounts have their own superblock, which needs to be initialized.
However, they do not have a fuse_fs_context associated with them, and
the root node's attributes should be taken from the mountpoint's node.

Extend fuse_fill_super_common() to work for submounts by making the @ctx
parameter optional, and by adding a @submount_finode parameter.

(There is a plain "unsigned" in an existing code block that is being
indented by this commit.  Extend it to "unsigned int" so checkpatch does
not complain.)

Signed-off-by: Max Reitz 
Signed-off-by: Miklos Szeredi

fuse: split fuse_mount off of fuse_conn

2020-09-18T13:17:41+00:00

We want to allow submounts for the same fuse_conn, but with different
superblocks so that each of the submounts has its own device ID.  To do
so, we need to split all mount-specific information off of fuse_conn
into a new fuse_mount structure, so that multiple mounts can share a
single fuse_conn.

We need to take care only to perform connection-level actions once (i.e.
when the fuse_conn and thus the first fuse_mount are established, or
when the last fuse_mount and thus the fuse_conn are destroyed).  For
example, fuse_sb_destroy() must invoke fuse_send_destroy() until the
last superblock is released.

To do so, we keep track of which fuse_mount is the root mount and
perform all fuse_conn-level actions only when this fuse_mount is
involved.

Signed-off-by: Max Reitz 
Reviewed-by: Stefan Hajnoczi 
Signed-off-by: Miklos Szeredi

fuse: drop fuse_conn parameter where possible

2020-09-18T13:17:41+00:00

With the last commit, all functions that handle some existing fuse_req
no longer need to be given the associated fuse_conn, because they can
get it from the fuse_req object.

Signed-off-by: Max Reitz 
Reviewed-by: Stefan Hajnoczi 
Signed-off-by: Miklos Szeredi