<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/fuse/ioctl.c, branch for-next</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>fuse: remove pages for requests and exclusively use folios</title>
<updated>2024-11-05T13:08:35+00:00</updated>
<author>
<name>Joanne Koong</name>
<email>joannelkoong@gmail.com</email>
</author>
<published>2024-10-24T17:18:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=68bfb7eb7f7de355d5b3812c25a2a36e9eead97b'/>
<id>68bfb7eb7f7de355d5b3812c25a2a36e9eead97b</id>
<content type='text'>
All fuse requests use folios instead of pages for transferring data.
Remove pages from the requests and exclusively use folios.

No functional changes.

[SzM: rename back folio_descs -&gt; descs, etc.]

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All fuse requests use folios instead of pages for transferring data.
Remove pages from the requests and exclusively use folios.

No functional changes.

[SzM: rename back folio_descs -&gt; descs, etc.]

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: convert ioctls to use folios</title>
<updated>2024-11-05T10:14:32+00:00</updated>
<author>
<name>Joanne Koong</name>
<email>joannelkoong@gmail.com</email>
</author>
<published>2024-10-24T17:18:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ac1cf6e3bbe3dd371bd61a423437c1f67bba8b2a'/>
<id>ac1cf6e3bbe3dd371bd61a423437c1f67bba8b2a</id>
<content type='text'>
Convert ioctl requests to use folios instead of pages.

No functional changes.

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Convert ioctl requests to use folios instead of pages.

No functional changes.

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: enable dynamic configuration of fuse max pages limit (FUSE_MAX_MAX_PAGES)</title>
<updated>2024-10-25T15:05:49+00:00</updated>
<author>
<name>Joanne Koong</name>
<email>joannelkoong@gmail.com</email>
</author>
<published>2024-09-23T17:13:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2b3933b1e0a0a4b758fbc164bb31db0c113a7e2c'/>
<id>2b3933b1e0a0a4b758fbc164bb31db0c113a7e2c</id>
<content type='text'>
Introduce the capability to dynamically configure the max pages limit
(FUSE_MAX_MAX_PAGES) through a sysctl. This allows system administrators
to dynamically set the maximum number of pages that can be used for
servicing requests in fuse.

Previously, this is gated by FUSE_MAX_MAX_PAGES which is statically set
to 256 pages. One result of this is that the buffer size for a write
request is limited to 1 MiB on a 4k-page system.

The default value for this sysctl is the original limit (256 pages).

$ sysctl -a | grep max_pages_limit
fs.fuse.max_pages_limit = 256

$ sysctl -n fs.fuse.max_pages_limit
256

$ echo 1024 | sudo tee /proc/sys/fs/fuse/max_pages_limit
1024

$ sysctl -n fs.fuse.max_pages_limit
1024

$ echo 65536 | sudo tee /proc/sys/fs/fuse/max_pages_limit
tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument

$ echo 0 | sudo tee /proc/sys/fs/fuse/max_pages_limit
tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument

$ echo 65535 | sudo tee /proc/sys/fs/fuse/max_pages_limit
65535

$ sysctl -n fs.fuse.max_pages_limit
65535

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Reviewed-by: Sweet Tea Dorminy &lt;sweettea-kernel@dorminy.me&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce the capability to dynamically configure the max pages limit
(FUSE_MAX_MAX_PAGES) through a sysctl. This allows system administrators
to dynamically set the maximum number of pages that can be used for
servicing requests in fuse.

Previously, this is gated by FUSE_MAX_MAX_PAGES which is statically set
to 256 pages. One result of this is that the buffer size for a write
request is limited to 1 MiB on a 4k-page system.

The default value for this sysctl is the original limit (256 pages).

$ sysctl -a | grep max_pages_limit
fs.fuse.max_pages_limit = 256

$ sysctl -n fs.fuse.max_pages_limit
256

$ echo 1024 | sudo tee /proc/sys/fs/fuse/max_pages_limit
1024

$ sysctl -n fs.fuse.max_pages_limit
1024

$ echo 65536 | sudo tee /proc/sys/fs/fuse/max_pages_limit
tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument

$ echo 0 | sudo tee /proc/sys/fs/fuse/max_pages_limit
tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument

$ echo 65535 | sudo tee /proc/sys/fs/fuse/max_pages_limit
65535

$ sysctl -n fs.fuse.max_pages_limit
65535

Signed-off-by: Joanne Koong &lt;joannelkoong@gmail.com&gt;
Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Reviewed-by: Sweet Tea Dorminy &lt;sweettea-kernel@dorminy.me&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: Add initial support for fs-verity</title>
<updated>2024-05-08T07:31:21+00:00</updated>
<author>
<name>Richard Fung</name>
<email>richardfung@google.com</email>
</author>
<published>2024-04-16T00:16:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9fe2a036a23ceeac402c4fde8ec37c02ab25f133'/>
<id>9fe2a036a23ceeac402c4fde8ec37c02ab25f133</id>
<content type='text'>
This adds support for the FS_IOC_ENABLE_VERITY and FS_IOC_MEASURE_VERITY
ioctls. The FS_IOC_READ_VERITY_METADATA is missing but from the
documentation, "This is a fairly specialized use case, and most fs-verity
users won’t need this ioctl."

Signed-off-by: Richard Fung &lt;richardfung@google.com&gt;
Acked-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This adds support for the FS_IOC_ENABLE_VERITY and FS_IOC_MEASURE_VERITY
ioctls. The FS_IOC_READ_VERITY_METADATA is missing but from the
documentation, "This is a fairly specialized use case, and most fs-verity
users won’t need this ioctl."

Signed-off-by: Richard Fung &lt;richardfung@google.com&gt;
Acked-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: ioctl: translate ENOSYS in outarg</title>
<updated>2023-06-21T09:17:36+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2023-06-07T15:49:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6a567e920fd0451bf29abc418df96c3365925770'/>
<id>6a567e920fd0451bf29abc418df96c3365925770</id>
<content type='text'>
Fuse shouldn't return ENOSYS from its ioctl implementation. If userspace
responds with ENOSYS it should be translated to ENOTTY.

There are two ways to return an error from the IOCTL request:

 - fuse_out_header.error
 - fuse_ioctl_out.result

Commit 02c0cab8e734 ("fuse: ioctl: translate ENOSYS") already fixed this
issue for the first case, but missed the second case.  This patch fixes the
second case.

Reported-by: Jonathan Katz &lt;jkatz@eitmlabs.org&gt;
Closes: https://lore.kernel.org/all/CALKgVmcC1VUV_gJVq70n--omMJZUb4HSh_FqvLTHgNBc+HCLFQ@mail.gmail.com/
Fixes: 02c0cab8e734 ("fuse: ioctl: translate ENOSYS")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fuse shouldn't return ENOSYS from its ioctl implementation. If userspace
responds with ENOSYS it should be translated to ENOTTY.

There are two ways to return an error from the IOCTL request:

 - fuse_out_header.error
 - fuse_ioctl_out.result

Commit 02c0cab8e734 ("fuse: ioctl: translate ENOSYS") already fixed this
issue for the first case, but missed the second case.  This patch fixes the
second case.

Reported-by: Jonathan Katz &lt;jkatz@eitmlabs.org&gt;
Closes: https://lore.kernel.org/all/CALKgVmcC1VUV_gJVq70n--omMJZUb4HSh_FqvLTHgNBc+HCLFQ@mail.gmail.com/
Fixes: 02c0cab8e734 ("fuse: ioctl: translate ENOSYS")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'fuse-update-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse</title>
<updated>2023-02-27T17:53:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-27T17:53:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d40b2f4c94f221bd5aab205f945e6f88d3df0929'/>
<id>d40b2f4c94f221bd5aab205f945e6f88d3df0929</id>
<content type='text'>
Pull fuse updates from Miklos Szeredi:

 - Fix regression in fileattr permission checking

 - Fix possible hang during PID namespace destruction

 - Add generic support for request extensions

 - Add supplementary group list extension

 - Add limited support for supplying supplementary groups in create
   requests

 - Documentation fixes

* tag 'fuse-update-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add inode/permission checks to fileattr_get/fileattr_set
  fuse: fix all W=1 kernel-doc warnings
  fuse: in fuse_flush only wait if someone wants the return code
  fuse: optional supplementary group in create requests
  fuse: add request extension
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull fuse updates from Miklos Szeredi:

 - Fix regression in fileattr permission checking

 - Fix possible hang during PID namespace destruction

 - Add generic support for request extensions

 - Add supplementary group list extension

 - Add limited support for supplying supplementary groups in create
   requests

 - Documentation fixes

* tag 'fuse-update-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add inode/permission checks to fileattr_get/fileattr_set
  fuse: fix all W=1 kernel-doc warnings
  fuse: in fuse_flush only wait if someone wants the return code
  fuse: optional supplementary group in create requests
  fuse: add request extension
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: add inode/permission checks to fileattr_get/fileattr_set</title>
<updated>2023-01-26T16:22:04+00:00</updated>
<author>
<name>Alexander Mikhalitsyn</name>
<email>aleksandr.mikhalitsyn@canonical.com</email>
</author>
<published>2023-01-26T10:23:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1cc4606d19e3710bfab3f6704b87ff9580493c69'/>
<id>1cc4606d19e3710bfab3f6704b87ff9580493c69</id>
<content type='text'>
It looks like these checks were accidentally lost during the conversion to
fileattr API.

Fixes: 72227eac177d ("fuse: convert to fileattr")
Cc: &lt;stable@vger.kernel.org&gt; # v5.13
Signed-off-by: Alexander Mikhalitsyn &lt;aleksandr.mikhalitsyn@canonical.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It looks like these checks were accidentally lost during the conversion to
fileattr API.

Fixes: 72227eac177d ("fuse: convert to fileattr")
Cc: &lt;stable@vger.kernel.org&gt; # v5.13
Signed-off-by: Alexander Mikhalitsyn &lt;aleksandr.mikhalitsyn@canonical.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: port -&gt;fileattr_set() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:27+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2023-01-13T11:49:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8782a9aea3ab4d697ad67d1f8ebca38a4e1c24ab'/>
<id>8782a9aea3ab4d697ad67d1f8ebca38a4e1c24ab</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>use less confusing names for iov_iter direction initializers</title>
<updated>2022-11-25T18:01:55+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2022-09-16T00:25:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=de4eda9de2d957ef2d6a8365a01e26a435e958cb'/>
<id>de4eda9de2d957ef2d6a8365a01e26a435e958cb</id>
<content type='text'>
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fuse: ioctl: translate ENOSYS</title>
<updated>2022-07-21T14:06:18+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2022-07-21T14:06:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=02c0cab8e7345b06f1c0838df444e2902e4138d3'/>
<id>02c0cab8e7345b06f1c0838df444e2902e4138d3</id>
<content type='text'>
Overlayfs may fail to complete updates when a filesystem lacks
fileattr/xattr syscall support and responds with an ENOSYS error code,
resulting in an unexpected "Function not implemented" error.

This bug may occur with FUSE filesystems, such as davfs2.

Steps to reproduce:

  # install davfs2, e.g., apk add davfs2
  mkdir /test mkdir /test/lower /test/upper /test/work /test/mnt
  yes '' | mount -t davfs -o ro http://some-web-dav-server/path \
    /test/lower
  mount -t overlay -o upperdir=/test/upper,lowerdir=/test/lower \
    -o workdir=/test/work overlay /test/mnt

  # when "some-file" exists in the lowerdir, this fails with "Function
  # not implemented", with dmesg showing "overlayfs: failed to retrieve
  # lower fileattr (/some-file, err=-38)"
  touch /test/mnt/some-file

The underlying cause of this regresion is actually in FUSE, which fails to
translate the ENOSYS error code returned by userspace filesystem (which
means that the ioctl operation is not supported) to ENOTTY.

Reported-by: Christian Kohlschütter &lt;christian@kohlschutter.com&gt;
Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
Fixes: 59efec7b9039 ("fuse: implement ioctl support")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Overlayfs may fail to complete updates when a filesystem lacks
fileattr/xattr syscall support and responds with an ENOSYS error code,
resulting in an unexpected "Function not implemented" error.

This bug may occur with FUSE filesystems, such as davfs2.

Steps to reproduce:

  # install davfs2, e.g., apk add davfs2
  mkdir /test mkdir /test/lower /test/upper /test/work /test/mnt
  yes '' | mount -t davfs -o ro http://some-web-dav-server/path \
    /test/lower
  mount -t overlay -o upperdir=/test/upper,lowerdir=/test/lower \
    -o workdir=/test/work overlay /test/mnt

  # when "some-file" exists in the lowerdir, this fails with "Function
  # not implemented", with dmesg showing "overlayfs: failed to retrieve
  # lower fileattr (/some-file, err=-38)"
  touch /test/mnt/some-file

The underlying cause of this regresion is actually in FUSE, which fails to
translate the ENOSYS error code returned by userspace filesystem (which
means that the ioctl operation is not supported) to ENOTTY.

Reported-by: Christian Kohlschütter &lt;christian@kohlschutter.com&gt;
Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
Fixes: 59efec7b9039 ("fuse: implement ioctl support")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
