Merge tag 'ovl-fixes-6.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs

Pull overlayfs fixes from Amir Goldstein:

- Various fixes for regressions due to conversion to new moun

Merge tag 'ovl-fixes-6.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs

Pull overlayfs fixes from Amir Goldstein:

- Various fixes for regressions due to conversion to new mount
api in v6.5

- Disable a new mount option syntax (append lowerdir) that was
added in v6.5 because we plan to add a different lowerdir
append syntax in v6.7

* tag 'ovl-fixes-6.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: temporarily disable appending lowedirs
ovl: fix regression in showing lowerdir mount option
ovl: fix regression in parsing of mount options with escaped comma
fs: factor out vfs_parse_monolithic_sep() helper

show more ...

fs: factor out vfs_parse_monolithic_sep() helper

Factor out vfs_parse_monolithic_sep() from generic_parse_monolithic(),
so filesystems could use it with a custom option separator callback.

Acked-by

fs: factor out vfs_parse_monolithic_sep() helper

Factor out vfs_parse_monolithic_sep() from generic_parse_monolithic(),
so filesystems could use it with a custom option separator callback.

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

show more ...

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes

Merge tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual filesystems.

Features:

- Block mode changes on symlinks and rectify our broken semantics

- Report file modifications via fsnotify() for splice

- Allow specifying an explicit timeout for the "rootwait" kernel
command line option. This allows to timeout and reboot instead of
always waiting indefinitely for the root device to show up

- Use synchronous fput for the close system call

Cleanups:

- Get rid of open-coded lockdep workarounds for async io submitters
and replace it all with a single consolidated helper

- Simplify epoll allocation helper

- Convert simple_write_begin and simple_write_end to use a folio

- Convert page_cache_pipe_buf_confirm() to use a folio

- Simplify __range_close to avoid pointless locking

- Disable per-cpu buffer head cache for isolated cpus

- Port ecryptfs to kmap_local_page() api

- Remove redundant initialization of pointer buf in pipe code

- Unexport the d_genocide() function which is only used within core
vfs

- Replace printk(KERN_ERR) and WARN_ON() with WARN()

Fixes:

- Fix various kernel-doc issues

- Fix refcount underflow for eventfds when used as EFD_SEMAPHORE

- Fix a mainly theoretical issue in devpts

- Check the return value of __getblk() in reiserfs

- Fix a racy assert in i_readcount_dec

- Fix integer conversion issues in various functions

- Fix LSM security context handling during automounts that prevented
NFS superblock sharing"

* tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
cachefiles: use kiocb_{start,end}_write() helpers
ovl: use kiocb_{start,end}_write() helpers
aio: use kiocb_{start,end}_write() helpers
io_uring: use kiocb_{start,end}_write() helpers
fs: create kiocb_{start,end}_write() helpers
fs: add kerneldoc to file_{start,end}_write() helpers
io_uring: rename kiocb_end_write() local helper
splice: Convert page_cache_pipe_buf_confirm() to use a folio
libfs: Convert simple_write_begin and simple_write_end to use a folio
fs/dcache: Replace printk and WARN_ON by WARN
fs/pipe: remove redundant initialization of pointer buf
fs: Fix kernel-doc warnings
devpts: Fix kernel-doc warnings
doc: idmappings: fix an error and rephrase a paragraph
init: Add support for rootwait timeout parameter
vfs: fix up the assert in i_readcount_dec
fs: Fix one kernel-doc comment
docs: filesystems: idmappings: clarify from where idmappings are taken
fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs
vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
...

show more ...

Merge tag 'v6.6-vfs.fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull mount API updates from Christian Brauner:
"This introduces FSCONFIG_CMD_CREATE_EXCL which allows usersp

Merge tag 'v6.6-vfs.fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull mount API updates from Christian Brauner:
"This introduces FSCONFIG_CMD_CREATE_EXCL which allows userspace to
implement something like

$ mount -t ext4 --exclusive /dev/sda /B

which fails if a superblock for the requested filesystem does already
exist instead of silently reusing an existing superblock.

Without it, in the sequence

$ move-mount -f xfs -o source=/dev/sda4 /A
$ move-mount -f xfs -o noacl,source=/dev/sda4 /B

the initial mounter will create a superblock. The second mounter will
reuse the existing superblock, creating a bind-mount (see [1] for the
source of the move-mount binary).

The problem is that reusing an existing superblock means all mount
options other than read-only and read-write will be silently ignored
even if they are incompatible requests. For example, the second mount
has requested no POSIX ACL support but since the existing superblock
is reused POSIX ACL support will remain enabled.

Such silent superblock reuse can easily become a security issue.

After adding support for FSCONFIG_CMD_CREATE_EXCL to mount(8) in
util-linux this can be fixed:

$ move-mount -f xfs --exclusive -o source=/dev/sda4 /A
$ move-mount -f xfs --exclusive -o noacl,source=/dev/sda4 /B
Device or resource busy | move-mount.c: 300: do_fsconfig: i xfs: reusing existing filesystem not allowed

This requires the new mount api. With the old mount api it would be
necessary to plumb this through every legacy filesystem's
file_system_type->mount() method. If they want this feature they are
most welcome to switch to the new mount api"

Link: https://github.com/brauner/move-mount-beneath [1]
Link: https://lore.kernel.org/linux-block/20230704-fasching-wertarbeit-7c6ffb01c83d@brauner
Link: https://lore.kernel.org/linux-block/20230705-pumpwerk-vielversprechend-a4b1fd947b65@brauner
Link: https://lore.kernel.org/linux-fsdevel/20230725-einnahmen-warnschilder-17779aec0a97@brauner
Link: https://lore.kernel.org/lkml/20230824-anzog-allheilmittel-e8c63e429a79@brauner/

* tag 'v6.6-vfs.fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: add FSCONFIG_CMD_CREATE_EXCL
fs: add vfs_cmd_reconfigure()
fs: add vfs_cmd_create()
super: remove get_tree_single_reconf()

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fs: Fix kernel-doc warnings

These have a variety of causes and a corresponding variety of solutions.

Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Message-Id: <20230818200824.27200

fs: Fix kernel-doc warnings

These have a variety of causes and a corresponding variety of solutions.

Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Message-Id: <20230818200824.2720007-1-willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing

When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior t

vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing

When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior to sget_fc() being called,
leading to failure to match existing superblocks.

This bug leads to messages like the following appearing in dmesg when
fscache is enabled:

NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)

Fix this by adding a new LSM hook to load fc->security for submount
creation.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode")
Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230808-master-v9-1-e0ecde888221@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

fs: add FSCONFIG_CMD_CREATE_EXCL

Summary
=======

This introduces FSCONFIG_CMD_CREATE_EXCL which will allows userspace to
implement something like mount -t ext4 --exclusive /dev/sda /B which
fails i

fs: add FSCONFIG_CMD_CREATE_EXCL

Summary
=======

This introduces FSCONFIG_CMD_CREATE_EXCL which will allows userspace to
implement something like mount -t ext4 --exclusive /dev/sda /B which
fails if a superblock for the requested filesystem does already exist:

Before this patch
-----------------

$ sudo ./move-mount -f xfs -o source=/dev/sda4 /A
Requesting filesystem type xfs
Mount options requested: source=/dev/sda4
Attaching mount at /A
Moving single attached mount
Setting key(source) with val(/dev/sda4)

$ sudo ./move-mount -f xfs -o source=/dev/sda4 /B
Requesting filesystem type xfs
Mount options requested: source=/dev/sda4
Attaching mount at /B
Moving single attached mount
Setting key(source) with val(/dev/sda4)

After this patch with --exclusive as a switch for FSCONFIG_CMD_CREATE_EXCL
--------------------------------------------------------------------------

$ sudo ./move-mount -f xfs --exclusive -o source=/dev/sda4 /A
Requesting filesystem type xfs
Request exclusive superblock creation
Mount options requested: source=/dev/sda4
Attaching mount at /A
Moving single attached mount
Setting key(source) with val(/dev/sda4)

$ sudo ./move-mount -f xfs --exclusive -o source=/dev/sda4 /B
Requesting filesystem type xfs
Request exclusive superblock creation
Mount options requested: source=/dev/sda4
Attaching mount at /B
Moving single attached mount
Setting key(source) with val(/dev/sda4)
Device or resource busy | move-mount.c: 300: do_fsconfig: i xfs: reusing existing filesystem not allowed

Details
=======

As mentioned on the list (cf. [1]-[3]) mount requests like
mount -t ext4 /dev/sda /A are ambigous for userspace. Either a new
superblock has been created and mounted or an existing superblock has
been reused and a bind-mount has been created.

This becomes clear in the following example where two processes create
the same mount for the same block device:

P1 P2
fd_fs = fsopen("ext4"); fd_fs = fsopen("ext4");
fsconfig(fd_fs, FSCONFIG_SET_STRING, "source", "/dev/sda"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "source", "/dev/sda");
fsconfig(fd_fs, FSCONFIG_SET_STRING, "dax", "always"); fsconfig(fd_fs, FSCONFIG_SET_STRING, "resuid", "1000");

// wins and creates superblock
fsconfig(fd_fs, FSCONFIG_CMD_CREATE, ...)
// finds compatible superblock of P1
// spins until P1 sets SB_BORN and grabs a reference
fsconfig(fd_fs, FSCONFIG_CMD_CREATE, ...)

fd_mnt1 = fsmount(fd_fs); fd_mnt2 = fsmount(fd_fs);
move_mount(fd_mnt1, "/A") move_mount(fd_mnt2, "/B")

Not just does P2 get a bind-mount but the mount options that P2
requestes are silently ignored. The VFS itself doesn't, can't and
shouldn't enforce filesystem specific mount option compatibility. It
only enforces incompatibility for read-only <-> read-write transitions:

mount -t ext4 /dev/sda /A
mount -t ext4 -o ro /dev/sda /B

The read-only request will fail with EBUSY as the VFS can't just
silently transition a superblock from read-write to read-only or vica
versa without risking security issues.

To userspace this silent superblock reuse can become a security issue in
because there is currently no straightforward way for userspace to know
that they did indeed manage to create a new superblock and didn't just
reuse an existing one.

This adds a new FSCONFIG_CMD_CREATE_EXCL command to fsconfig() that
returns EBUSY if an existing superblock would be reused. Userspace that
needs to be sure that it did create a new superblock with the requested
mount options can request superblock creation using this command. If the
command succeeds they can be sure that they did create a new superblock
with the requested mount options.

This requires the new mount api. With the old mount api it would be
necessary to plumb this through every legacy filesystem's
file_system_type->mount() method. If they want this feature they are
most welcome to switch to the new mount api.

Following is an analysis of the effect of FSCONFIG_CMD_CREATE_EXCL on
each high-level superblock creation helper:

(1) get_tree_nodev()

Always allocate new superblock. Hence, FSCONFIG_CMD_CREATE and
FSCONFIG_CMD_CREATE_EXCL are equivalent.

The binderfs or overlayfs filesystems are examples.

(4) get_tree_keyed()

Finds an existing superblock based on sb->s_fs_info. Hence,
FSCONFIG_CMD_CREATE would reuse an existing superblock whereas
FSCONFIG_CMD_CREATE_EXCL would reject it with EBUSY.

The mqueue or nfsd filesystems are examples.

(2) get_tree_bdev()

This effectively works like get_tree_keyed().

The ext4 or xfs filesystems are examples.

(3) get_tree_single()

Only one superblock of this filesystem type can ever exist.
Hence, FSCONFIG_CMD_CREATE would reuse an existing superblock
whereas FSCONFIG_CMD_CREATE_EXCL would reject it with EBUSY.

The securityfs or configfs filesystems are examples.

Note that some single-instance filesystems never destroy the
superblock once it has been created during the first mount. For
example, if securityfs has been mounted at least onces then the
created superblock will never be destroyed again as long as there is
still an LSM making use it. Consequently, even if securityfs is
unmounted and the superblock seemingly destroyed it really isn't
which means that FSCONFIG_CMD_CREATE_EXCL will continue rejecting
reusing an existing superblock.

This is acceptable thugh since special purpose filesystems such as
this shouldn't have a need to use FSCONFIG_CMD_CREATE_EXCL anyway
and if they do it's probably to make sure that mount options aren't
ignored.

Following is an analysis of the effect of FSCONFIG_CMD_CREATE_EXCL on
filesystems that make use of the low-level sget_fc() helper directly.
They're all effectively variants on get_tree_keyed(), get_tree_bdev(),
or get_tree_nodev():

(5) mtd_get_sb()

Similar logic to get_tree_keyed().

(6) afs_get_tree()

Similar logic to get_tree_keyed().

(7) ceph_get_tree()

Similar logic to get_tree_keyed().

Already explicitly allows forcing the allocation of a new superblock
via CEPH_OPT_NOSHARE. This turns it into get_tree_nodev().

(8) fuse_get_tree_submount()

Similar logic to get_tree_nodev().

(9) fuse_get_tree()

Forces reuse of existing FUSE superblock.

Forces reuse of existing superblock if passed in file refers to an
existing FUSE connection.
If FSCONFIG_CMD_CREATE_EXCL is specified together with an fd
referring to an existing FUSE connections this would cause the
superblock reusal to fail. If reusing is the intent then
FSCONFIG_CMD_CREATE_EXCL shouldn't be specified.

(10) fuse_get_tree()
-> get_tree_nodev()

Same logic as in get_tree_nodev().

(11) fuse_get_tree()
-> get_tree_bdev()

Same logic as in get_tree_bdev().

(12) virtio_fs_get_tree()

Same logic as get_tree_keyed().

(13) gfs2_meta_get_tree()

Forces reuse of existing gfs2 superblock.

Mounting gfs2meta enforces that a gf2s superblock must already
exist. If not, it will error out. Consequently, mounting gfs2meta
with FSCONFIG_CMD_CREATE_EXCL would always fail. If reusing is the
intent then FSCONFIG_CMD_CREATE_EXCL shouldn't be specified.

(14) kernfs_get_tree()

Similar logic to get_tree_keyed().

(15) nfs_get_tree_common()

Similar logic to get_tree_keyed().

Already explicitly allows forcing the allocation of a new superblock
via NFS_MOUNT_UNSHARED. This effectively turns it into
get_tree_nodev().

Link: [1] https://lore.kernel.org/linux-block/20230704-fasching-wertarbeit-7c6ffb01c83d@brauner
Link: [2] https://lore.kernel.org/linux-block/20230705-pumpwerk-vielversprechend-a4b1fd947b65@brauner
Link: [3] https://lore.kernel.org/linux-fsdevel/20230725-einnahmen-warnschilder-17779aec0a97@brauner
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230802-vfs-super-exclusive-v2-4-95dc4e41b870@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

ASoC: Merge v6.5-rc2

Get a similar baseline to my other branches, and fixes for people using
the branch.

Merge v6.5-rc1 into drm-misc-fixes

Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge branch 'master' into mm-hotfixes-stable

Merge tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
"Miscellaneous features, cleanups, and fixes for vfs and individual

Merge tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
"Miscellaneous features, cleanups, and fixes for vfs and individual fs

Features:

- Use mode 0600 for file created by cachefilesd so it can be run by
unprivileged users. This aligns them with directories which are
already created with mode 0700 by cachefilesd

- Reorder a few members in struct file to prevent some false sharing
scenarios

- Indicate that an eventfd is used a semaphore in the eventfd's
fdinfo procfs file

- Add a missing uapi header for eventfd exposing relevant uapi
defines

- Let the VFS protect transitions of a superblock from read-only to
read-write in addition to the protection it already provides for
transitions from read-write to read-only. Protecting read-only to
read-write transitions allows filesystems such as ext4 to perform
internal writes, keeping writers away until the transition is
completed

Cleanups:

- Arnd removed the architecture specific arch_report_meminfo()
prototypes and added a generic one into procfs.h. Note, we got a
report about a warning in amdpgpu codepaths that suggested this was
bisectable to this change but we concluded it was a false positive

- Remove unused parameters from split_fs_names()

- Rename put_and_unmap_page() to unmap_and_put_page() to let the name
reflect the order of the cleanup operation that has to unmap before
the actual put

- Unexport buffer_check_dirty_writeback() as it is not used outside
of block device aops

- Stop allocating aio rings from highmem

- Protecting read-{only,write} transitions in the VFS used open-coded
barriers in various places. Replace them with proper little helpers
and document both the helpers and all barrier interactions involved
when transitioning between read-{only,write} states

- Use flexible array members in old readdir codepaths

Fixes:

- Use the correct type __poll_t for epoll and eventfd

- Replace all deprecated strlcpy() invocations, whose return value
isn't checked with an equivalent strscpy() call

- Fix some kernel-doc warnings in fs/open.c

- Reduce the stack usage in jffs2's xattr codepaths finally getting
rid of this: fs/jffs2/xattr.c:887:1: error: the frame size of 1088
bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
royally annoying compilation warning

- Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY where an int and not
fmode_t is required to avoid fmode_t to integer degradation
warnings

- Create coredumps with O_WRONLY instead of O_RDWR. There's a long
explanation in that commit how O_RDWR is actually a bug which we
found out with the help of Linus and git archeology

- Fix "no previous prototype" warnings in the pipe codepaths

- Add overflow calculations for remap_verify_area() as a signed
addition overflow could be triggered in xfstests

- Fix a null pointer dereference in sysv

- Use an unsigned variable for length calculations in jfs avoiding
compilation warnings with gcc 13

- Fix a dangling pipe pointer in the watch queue codepath

- The legacy mount option parser provided as a fallback by the VFS
for filesystems not yet converted to the new mount api did prefix
the generated mount option string with a leading ',' causing issues
for some filesystems

- Fix a repeated word in a comment in fs.h

- autofs: Update the ctime when mtime is updated as mandated by
POSIX"

* tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
readdir: Replace one-element arrays with flexible-array members
fs: Provide helpers for manipulating sb->s_readonly_remount
fs: Protect reconfiguration of sb read-write from racing writes
eventfd: add a uapi header for eventfd userspace APIs
autofs: set ctime as well when mtime changes on a dir
eventfd: show the EFD_SEMAPHORE flag in fdinfo
fs/aio: Stop allocating aio rings from HIGHMEM
fs: Fix comment typo
fs: unexport buffer_check_dirty_writeback
fs: avoid empty option when generating legacy mount string
watch_queue: prevent dangling pipe pointer
fs.h: Optimize file struct to prevent false sharing
highmem: Rename put_and_unmap_page() to unmap_and_put_page()
cachefiles: Allow the cache to be non-root
init: remove unused names parameter in split_fs_names()
jfs: Use unsigned variable for length calculations
fs/sysv: Null check to prevent null-ptr-deref bug
fs: use UB-safe check for signed addition overflow in remap_verify_area
procfs: consolidate arch_report_meminfo declaration
fs: pipe: reveal missing function protoypes
...

show more ...

fs: avoid empty option when generating legacy mount string

As each option string fragment is always prepended with a comma it would
happen that the whole string always starts with a comma. This coul

fs: avoid empty option when generating legacy mount string

As each option string fragment is always prepended with a comma it would
happen that the whole string always starts with a comma. This could be
interpreted by filesystem drivers as an empty option and may produce
errors.

For example the NTFS driver from ntfs.ko behaves like this and fails
when mounted via the new API.

Link: https://github.com/util-linux/util-linux/issues/2298
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Fixes: 3e1aeb00e6d1 ("vfs: Implement a filesystem superblock creation/configuration context")
Cc: stable@vger.kernel.org
Message-Id: <20230607-fs-empty-option-v1-1-20c8dbf4671b@weissschuh.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

Merge tag 'v5.18'

Linux 5.18

Merge branches 'fixes' and 'misc' into for-linus

Merge branch 'for-5.18/amd-sfh' into for-linus

- dead code elimination (Christophe JAILLET)

Merge tag 'v5.17-rc4' into for-linus

Merge with mainline to get the Intel ASoC generic helpers header and
other changes.

Merge tag 'v5.17-rc4' into next

Sync up with mainline to get the latest changes in HID subsystem.

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

First backmerge into drm-misc-next. Required for more helpers backmerged,
and to pull in 5.17 (rc2).

Signed-off-by: Maarten Lankhorst

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

First backmerge into drm-misc-next. Required for more helpers backmerged,
and to pull in 5.17 (rc2).

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge tag 'kvmarm-fixes-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.17, take #2

- A couple of fixes when handling an exception while a SEr

Merge tag 'kvmarm-fixes-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.17, take #2

- A couple of fixes when handling an exception while a SError has been
delivered

- Workaround for Cortex-A510's single-step[ erratum

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Merge drm/drm-next into drm-intel-gt-next

Backmerge to bring in 5.17-rc2 to introduce a common baseline
to merge i915_regs changes from drm-intel-next.

Signed-off-by: Joonas Lahtinen <joonas.lahtin

Merge drm/drm-next into drm-intel-gt-next

Backmerge to bring in 5.17-rc2 to introduce a common baseline
to merge i915_regs changes from drm-intel-next.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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Merge drm/drm-next into drm-intel-next

Catch-up with 5.17-rc2 and trying to align with drm-intel-gt-next
for a possible topic branch for merging the split of i915_regs...

Signed-off-by: Rodrigo Viv

Merge drm/drm-next into drm-intel-next

Catch-up with 5.17-rc2 and trying to align with drm-intel-gt-next
for a possible topic branch for merging the split of i915_regs...

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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