We ran into issues where mount(8) passed multiple lower layers as one
big string through fsconfig(). But the fsconfig() FSCONFIG_SET_STRING
option is limited to 256 bytes in strndup_user(). While this would be
fixable by extending the fsconfig() buffer I'd rather encourage users to
append layers via multiple fsconfig() calls as the interface allows
nicely for this. This has also been requested as a feature before.

With this port to the new mount api the following will be possible:

        fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", "/lower1", 0);

        /* set upper layer */
        fsconfig(fs_fd, FSCONFIG_SET_STRING, "upperdir", "/upper", 0);

        /* append "/lower2", "/lower3", and "/lower4" */
        fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", ":/lower2:/lower3:/lower4", 0);

        /* turn index feature on */
        fsconfig(fs_fd, FSCONFIG_SET_STRING, "index", "on", 0);

        /* append "/lower5" */
        fsconfig(fs_fd, FSCONFIG_SET_STRING, "lowerdir", ":/lower5", 0);

Specifying ':' would have been rejected so this isn't a regression. And
we can't simply use "lowerdir=/lower" to append on top of existing
layers as "lowerdir=/lower,lowerdir=/other-lower" would make
"/other-lower" the only lower layer so we'd break uapi if we changed
this. So the ':' prefix seems a good compromise.

Users can choose to specify multiple layers at once or individual
layers. A layer is appended if it starts with ":". This requires that
the user has already added at least one layer before. If lowerdir is
specified again without a leading ":" then all previous layers are
dropped and replaced with the new layers. If lowerdir is specified and
empty than all layers are simply dropped.

An additional change is that overlayfs will now parse and resolve layers
right when they are specified in fsconfig() instead of deferring until
super block creation. This allows users to receive early errors.

It also allows users to actually use up to 500 layers something which
was theoretically possible but ended up not working due to the mount
option string passed via mount(2) being too large.

This also allows a more privileged process to set config options for a
lesser privileged process as the creds for fsconfig() and the creds for
fsopen() can differ. We could restrict that they match by enforcing that
the creds of fsopen() and fsconfig() match but I don't see why that
needs to be the case and allows for a good delegation mechanism.

Plus, in the future it means we're able to extend overlayfs mount
options and allow users to specify layers via file descriptors instead
of paths:

        fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower1", dirfd);

        /* append */
        fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower2", dirfd);

        /* append */
        fsconfig(FSCONFIG_SET_PATH{_EMPTY}, "lowerdir", "lower3", dirfd);

        /* clear all layers specified until now */
        fsconfig(FSCONFIG_SET_STRING, "lowerdir", NULL, 0);

This would be especially nice if users create an overlayfs mount on top
of idmapped layers or just in general private mounts created via
open_tree(OPEN_TREE_CLONE). Those mounts would then never have to appear
anywhere in the filesystem. But for now just do the minimal thing.

We should probably aim to move more validation into ovl_fs_parse_param()
so users get errors before fsconfig(FSCONFIG_CMD_CREATE). But that can
be done in additional patches later.

This is now also rebased on top of the lazy lowerdata lookup which
allows the specificatin of data only layers using the new "::" syntax.

The rules are simple. A data only layers cannot be followed by any
regular layers and data layers must be preceeded by at least one regular
layer.

Parsing the lowerdir mount option must change because of this. The
original patchset used the old lowerdir parsing function to split a
lowerdir mount option string such as:

        lowerdir=/lower1:/lower2::/lower3::/lower4

simply replacing each non-escaped ":" by "\0". So sequences of
non-escaped ":" were counted as layers. For example, the previous
lowerdir mount option above would've counted 6 layers instead of 4 and a
lowerdir mount option such as:

        lowerdir="/lower1:/lower2::/lower3::/lower4:::::::::::::::::::::::::::"

would be counted as 33 layers. Other than being ugly this didn't matter
much because kern_path() would reject the first "\0" layer. However,
this overcounting of layers becomes problematic when we base allocations
on it where we very much only want to allocate space for 4 layers
instead of 33.

So the new parsing function rejects non-escaped sequences of colons
other than ":" and "::" immediately instead of relying on kern_path().

Link: https://github.com/util-linux/util-linux/issues/2287
Link: https://github.com/util-linux/util-linux/issues/1992
Link: https://bugs.archlinux.org/task/78702
Link: https://lore.kernel.org/linux-unionfs/20230530-klagen-zudem-32c0908c2108@braunerSigned-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

We recently ported util-linux to the new mount api. Now the mount(8)
tool will by default use the new mount api. While trying hard to fall
back to the old mount api gracefully there are still cases where we run
into issues that are difficult to handle nicely.

Now with mount(8) and libmount supporting the new mount api I expect an
increase in the number of bug reports and issues we're going to see with
filesystems that don't yet support the new mount api. So it's time we
rectify this.

When ovl_fill_super() fails before setting sb->s_root, we need to cleanup
sb->s_fs_info.  The logic is a bit convoluted but tl;dr: If sget_fc() has
succeeded fc->s_fs_info will have been transferred to sb->s_fs_info.
So by the time ->fill_super()/ovl_fill_super() is called fc->s_fs_info
is NULL consequently fs_context->free() won't call ovl_free_fs().

If we fail before sb->s_root() is set then ->put_super() won't be called
which would call ovl_free_fs(). IOW, if we fail in ->fill_super() before
sb->s_root we have to clean it up.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

For parsing a single mount option.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Do all the logic to set the mode during mount options parsing and
do not keep the option string around.

Use a constant_table to translate from enum redirect mode to string
in preperation for new mount api option parsing.

The mount option "off" is translated to either "follow" or "nofollow",
depending on the "redirect_always_follow" build/module config, so
in effect, there are only three possible redirect modes.

This results in a minor change to the string that is displayed
in show_options() - when redirect_dir is enabled by default and the user
mounts with the option "redirect_dir=off", instead of displaying the mode
"redirect_dir=off" in show_options(), the displayed mode will be either
"redirect_dir=follow" or "redirect_dir=nofollow", depending on the value
of "redirect_always_follow" build/module config.

The displayed mode reflects the effective mode, so mounting overlayfs
again with the dispalyed redirect_dir option will result with the same
effective and displayed mode.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Internal ovl methods should use ovl_fs and not sb as much as
possible.

Use a constant_table to translate from enum xino mode to string
in preperation for new mount api option parsing.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Change the semantics to take a reference on upperdentry instead
of transferrig the reference.

This is needed for upcoming port to new mount api.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

The default common case is that whiteout sharing is enabled.
Change to storing the negated no_shared_whiteout state, so we will not
need to initialize it.

This is the first step towards removing all config and feature
initializations out of ovl_fill_super().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Porting overlayfs to the new amount api I started experiencing random
crashes that couldn't be explained easily. So after much debugging and
reasoning it became clear that struct ovl_entry requires the point to
struct vfsmount to be the first member and of type struct vfsmount.

During the port I added a new member at the beginning of struct
ovl_entry which broke all over the place in the form of random crashes
and cache corruptions. While there's a comment in ovl_free_fs() to the
effect of "Hack! Reuse ofs->layers as a vfsmount array before freeing
it" there's no such comment on struct ovl_entry which makes this easy to
trip over.

Add a comment and two static asserts for both the offset and the type of
pointer in struct ovl_entry.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Defer lookup of lowerdata in the data-only layers to first data access
or before copy up.

We perform lowerdata lookup before copy up even if copy up is metadata
only copy up.  We can further optimize this lookup later if needed.

We do best effort lazy lookup of lowerdata for d_real_inode(), because
this interface does not expect errors.  The only current in-tree caller
of d_real_inode() is trace_uprobe and this caller is likely going to be
followed reading from the file, before placing uprobes on offset within
the file, so lowerdata should be available when setting the uprobe.
Tested-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Make the code handle the case of numlower > 1 and missing lowerdata
dentry gracefully.

Missing lowerdata dentry is an indication for lazy lookup of lowerdata
and in that case the lowerdata_redirect path is stored in ovl_inode.

Following commits will defer lookup and perform the lazy lookup on
access.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.

In this case, ovl_lookup() stores the redirect path from metacopy to
lowerdata in ovl_inode, which is going to be used later to perform the
lazy lowerdata lookup.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Lookup in data-only layers only for a lower metacopy with an absolute
redirect xattr.

The metacopy xattr is not checked on files found in the data-only layers
and redirect xattr are not followed in the data-only layers.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Introduce the format lowerdir=lower1:lower2::lowerdata1::lowerdata2
where the lower layers on the right of the :: separators are not merged
into the overlayfs merge dirs.

Data-only lower layers are only allowed at the bottom of the stack.

The files in those layers are only meant to be accessible via absolute
redirect from metacopy files in lower layers.  Following changes will
implement lookup in the data layers.

This feature was requested for composefs ostree use case, where the
lower data layer should only be accessiable via absolute redirects
from metacopy inodes.

The lower data layers are not required to a have a unique uuid or any
uuid at all, because they are never used to compose the overlayfs inode
st_ino/st_dev.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

There is nothing in the out goto target of ovl_get_layers().
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.

Use accessors ovl_lowerdata*() to get the lowerdata whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

The ovl_inode contains a copy of lowerpath in lowerstack[0], so the
lowerpath member can be removed.

Use accessor ovl_lowerpath() to get the lowerpath whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

The lower stacks of all the ovl inode aliases should be identical
and there is redundant information in ovl_entry and ovl_inode.

Move lowerstack into ovl_inode and keep only the OVL_E_FLAGS
per overlay dentry.

Following patches will deduplicate redundant ovl_inode fields.

Note that for pure upper and negative dentries, OVL_E(dentry) may be
NULL now, so it is imporatnt to use the ovl_numlower() accessor.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

In preparation for moving lowerstack into ovl_inode.

Note that in ovl_lookup() the temp stack dentry refs are now cloned
into the final ovl_lowerstack instead of being transferred, so cleanup
always needs to call ovl_stack_free(stack).
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

This helps fortify against dereferencing a NULL ovl_entry,
before we move the ovl_entry reference into ovl_inode.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Instead of open coded instances, because we are about to split
the two apart.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

After copy up, we may need to update d_flags if upper dentry is on a
remote fs and lower dentries are not.

Add helpers to allow incremental update of the revalidate flags.

Fixes: bccece1e ("ovl: allow remote upper")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Following process:
         P1                     P2
 path_openat
  link_path_walk
   may_lookup
    inode_permission(rcu)
     ovl_permission
      acl_permission_check
       check_acl
        get_cached_acl_rcu
	 ovl_get_inode_acl
	  realinode = ovl_inode_real(ovl_inode)
	                      drop_cache
		               __dentry_kill(ovl_dentry)
				iput(ovl_inode)
		                 ovl_destroy_inode(ovl_inode)
		                  dput(oi->__upperdentry)
		                   dentry_kill(upperdentry)
		                    dentry_unlink_inode
				     upperdentry->d_inode = NULL
	    ovl_inode_upper
	     upperdentry = ovl_i_dentry_upper(ovl_inode)
	     d_inode(upperdentry) // returns NULL
	  IS_POSIXACL(realinode) // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
  [  205.472797] BUG: kernel NULL pointer dereference, address:
                 0000000000000028
  [  205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted
                 6.3.0-12064-g2edfa098e750-dirty #1216
  [  205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300
  [  205.489584] Call Trace:
  [  205.489812]  <TASK>
  [  205.490014]  ovl_get_inode_acl+0x26/0x30
  [  205.490466]  get_cached_acl_rcu+0x61/0xa0
  [  205.490908]  generic_permission+0x1bf/0x4e0
  [  205.491447]  ovl_permission+0x79/0x1b0
  [  205.491917]  inode_permission+0x15e/0x2c0
  [  205.492425]  link_path_walk+0x115/0x550
  [  205.493311]  path_lookupat.isra.0+0xb2/0x200
  [  205.493803]  filename_lookup+0xda/0x240
  [  205.495747]  vfs_fstatat+0x7b/0xb0

Fetch a reproducer in [Link].

Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217404
Fixes: 332f606b ("ovl: enable RCU'd ->get_acl()")
Cc: <stable@vger.kernel.org> # v5.15
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Following process:
          P1                     P2
 path_lookupat
  link_path_walk
   inode_permission
    ovl_permission
      ovl_i_path_real(inode, &realpath)
        path->dentry = ovl_i_dentry_upper(inode)
                          drop_cache
			   __dentry_kill(ovl_dentry)
		            iput(ovl_inode)
		             ovl_destroy_inode(ovl_inode)
		              dput(oi->__upperdentry)
		               dentry_kill(upperdentry)
		                dentry_unlink_inode
				 upperdentry->d_inode = NULL
      realinode = d_inode(realpath.dentry) // return NULL
      inode_permission(realinode)
       inode->i_sb  // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
  [  335.664979] BUG: kernel NULL pointer dereference,
                 address: 0000000000000002
  [  335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0
  [  335.669956] RIP: 0010:inode_permission+0x33/0x2c0
  [  335.678939] Call Trace:
  [  335.679165]  <TASK>
  [  335.679371]  ovl_permission+0xde/0x320
  [  335.679723]  inode_permission+0x15e/0x2c0
  [  335.680090]  link_path_walk+0x115/0x550
  [  335.680771]  path_lookupat.isra.0+0xb2/0x200
  [  335.681170]  filename_lookup+0xda/0x240
  [  335.681922]  vfs_statx+0xa6/0x1f0
  [  335.682233]  vfs_fstatat+0x7b/0xb0

Fetch a reproducer in [Link].

Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217405
Fixes: 4b7791b2 ("ovl: handle idmappings in ovl_permission()")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Let helper ovl_i_path_real() return the realinode to prepare for
checking non-null realinode in RCU walking path.

[msz] Use d_inode_rcu() since we are depending on the consitency
between dentry and inode being non-NULL in an RCU setting.
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Fixes: ffa5723c ("ovl: store lower path in ovl_inode")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

Pull x86 fix from Borislav Petkov:

 - Set up the kernel CS earlier in the boot process in case EFI boots
   the kernel after bypassing the decompressor and the CS descriptor
   used ends up being the EFI one which is not mapped in the identity
   page table, leading to early SEV/SNP guest communication exceptions
   resulting in the guest crashing

* tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/head/64: Switch to KERNEL_CS as soon as new GDT is installed

Pull smb server fixes from Steve French:
 "Five smb3 server fixes, all also for stable:

   - Fix four slab out of bounds warnings: improve checks for protocol
     id, and for small packet length, and for create context parsing,
     and for negotiate context parsing

   - Fix for incorrect dereferencing POSIX ACLs"

* tag '6.4-rc5-smb3-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: validate smb request protocol id
  ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop
  ksmbd: fix posix_acls and acls dereferencing possible ERR_PTR()
  ksmbd: fix out-of-bound read in parse_lease_state()
  ksmbd: fix out-of-bound read in deassemble_neg_contexts()

Pull i2c fixes from Wolfram Sang:
 "Biggest news is that Andi Shyti steps in for maintaining the
  controller drivers. Thank you very much!

  Other than that, one new driver maintainer and the rest is usual
  driver bugfixes. at24 has a Kconfig dependecy fix"

* tag 'i2c-for-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: Add entries for Renesas RZ/V2M I2C driver
  eeprom: at24: also select REGMAP
  i2c: sprd: Delete i2c adapter in .remove's error path
  i2c: mv64xxx: Fix reading invalid status value in atomic mode
  i2c: designware: fix idx_write_cnt in read loop
  i2c: mchp-pci1xxxx: Avoid cast to incompatible function type
  i2c: img-scb: Fix spelling mistake "innacurate" -> "inaccurate"
  MAINTAINERS: Add myself as I2C host drivers maintainer

Pull soundwire fixes from Vinod Koul:
 "Core fix for missing flag clear, error patch handling in qcom driver
  and BIOS quirk for HP Spectre x360:

   - HP Spectre x360 soundwire DMI quirk

   - Error path handling for qcom driver

   - Core fix for missing clear of alloc_slave_rt"

* tag 'soundwire-6.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire:
  soundwire: stream: Add missing clear of alloc_slave_rt
  soundwire: qcom: add proper error paths in qcom_swrm_startup()
  soundwire: dmi-quirks: add new mapping for HP Spectre x360

Pull ARM SoC fixes from Arnd Bergmann:
 "Most of the changes this time are for the Qualcomm Snapdragon
  platforms.

  There are bug fixes for error handling in Qualcomm icc-bwmon,
  rpmh-rsc, ramp_controller and rmtfs driver as well as the AMD tee
  firmware driver and a missing initialization in the Arm ff-a firmware
  driver. The Qualcomm RPMh and EDAC drivers need some rework to work
  correctly on all supported chips.

  The DT fixes include:

   - i.MX8 fixes for gpio, pinmux and clock settings

   - ADS touchscreen gpio polarity settings in several machines

   - Address dtb warnings for caches, panel and input-enable properties
     on Qualcomm platforms

   - Incorrect data on qualcomm platforms fir SA8155P power domains,
     SM8550 LLCC, SC7180-lite SDRAM frequencies and SM8550 soundwire

   - Remoteproc firmware paths are corrected for Sony Xperia 10 IV"

* tag 'arm-fixes-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (36 commits)
  firmware: arm_ffa: Set handle field to zero in memory descriptor
  ARM: dts: Fix erroneous ADS touchscreen polarities
  arm64: dts: imx8mn-beacon: Fix SPI CS pinmux
  arm64: dts: imx8-ss-dma: assign default clock rate for lpuarts
  arm64: dts: imx8qm-mek: correct GPIOs for USDHC2 CD and WP signals
  EDAC/qcom: Get rid of hardcoded register offsets
  EDAC/qcom: Remove superfluous return variable assignment in qcom_llcc_core_setup()
  arm64: dts: qcom: sm8550: Use the correct LLCC register scheme
  dt-bindings: cache: qcom,llcc: Fix SM8550 description
  arm64: dts: qcom: sc7180-lite: Fix SDRAM freq for misidentified sc7180-lite boards
  arm64: dts: qcom: sm8550: use uint16 for Soundwire interval
  soc: qcom: rpmhpd: Add SA8155P power domains
  arm64: dts: qcom: Split out SA8155P and use correct RPMh power domains
  dt-bindings: power: qcom,rpmpd: Add SA8155P
  soc: qcom: Rename ice to qcom_ice to avoid module name conflict
  soc: qcom: rmtfs: Fix error code in probe()
  soc: qcom: ramp_controller: Fix an error handling path in qcom_ramp_controller_probe()
  ARM: dts: at91: sama7g5ek: fix debounce delay property for shdwc
  ARM: at91: pm: fix imbalanced reference counter for ethernet devices
  arm64: dts: qcom: sm6375-pdx225: Fix remoteproc firmware paths
  ...

Pull block fixes from Jens Axboe:

 - Fix an issue with the hardware queue nr_active, causing it to become
   imbalanced (Tian)

 - Fix an issue with null_blk not releasing pages if configured as
   memory backed (Nitesh)

 - Fix a locking issue in dasd (Jan)

* tag 'block-6.4-2023-06-09' of git://git.kernel.dk/linux:
  s390/dasd: Use correct lock while counting channel queue length
  null_blk: Fix: memory release when memory_backed=1
  blk-mq: fix blk_mq_hw_ctx active request accounting

Pull virtio bug fixes from Michael Tsirkin:
 "A bunch of fixes all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  tools/virtio: use canonical ftrace path
  vhost_vdpa: support PACKED when setting-getting vring_base
  vhost: support PACKED when setting-getting vring_base
  vhost: Fix worker hangs due to missed wake up calls
  vhost: Fix crash during early vhost_transport_send_pkt calls
  vhost_net: revert upend_idx only on retriable error
  vhost_vdpa: tell vqs about the negotiated
  vdpa/mlx5: Fix hang when cvq commands are triggered during device unregister
  tools/virtio: Add .gitignore for ringtest
  tools/virtio: Fix arm64 ringtest compilation error
  vduse: avoid empty string for dev name
  vhost: use kzalloc() instead of kmalloc() followed by memset()

Pull ceph fixes from Ilya Dryomov:
 "A fix for a potential data corruption in differential backup and
  snapshot-based mirroring scenarios in RBD and a reference counting
  fixup to avoid use-after-free in CephFS, all marked for stable"

* tag 'ceph-for-6.4-rc6' of https://github.com/ceph/ceph-client:
  ceph: fix use-after-free bug for inodes when flushing capsnaps
  rbd: get snapshot context after exclusive lock is ensured to be held
  rbd: move RBD_OBJ_FLAG_COPYUP_ENABLED flag setting

The lock around counting the channel queue length in the BIODASDINFO
ioctl was incorrectly changed to the dasd_block->queue_lock with commit
583d6535 ("dasd: remove dead code"). This can lead to endless list
iterations and a subsequent crash.

The queue_lock is supposed to be used only for queue lists belonging to
dasd_block. For dasd_device related queue lists the ccwdev lock must be
used.

Fix the mentioned issues by correctly using the ccwdev lock instead of
the queue lock.

Fixes: 583d6535 ("dasd: remove dead code")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20230609153750.1258763-2-sth@linux.ibm.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix to avoid ISA-disallowed privilege mappings that can result from
   WRITE+EXEC mmap requests from userspace.

 - A fix for kfence to handle the huge pages.

 - A fix to avoid converting misaligned VAs to huge pages.

 - ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE has been selected so kprobe
   can understand user pointers.

* tag 'riscv-for-linus-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: fix kprobe __user string arg print fault issue
  riscv: Check the virtual alignment before choosing a map size
  riscv: Fix kfence now that the linear mapping can be backed by PUD/P4D/PGD
  riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readable

Pull s390 fixes from Alexander Gordeev:

 - Avoid linker error for randomly generated config file that has
   CONFIG_BRANCH_PROFILE_NONE enabled and make it similar to riscv, x86
   and also to commit 4bf3ec38 ("s390: disable branch profiling for
   vdso").

 - Currently, if the device is offline and all the channel paths are
   either configured or varied offline, the associated subchannel gets
   unregistered. Don't unregister the subchannel, instead unregister
   offline device.

* tag 's390-6.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/purgatory: disable branch profiling
  s390/cio: unregister device when the only path is gone

Pull gpio fixes from Bartosz Golaszewski:
 "Two fixes for the GPIO testing module and one commit making Andy a
  reviewer for the GPIO subsystem:

   - fix a memory corruption bug in gpio-sim

   - fix inconsistencies in user-space configuration of gpio-sim

   - make Andy Shevchenko a reviewer for the GPIO subsystem"

* tag 'gpio-fixes-for-v6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  MAINTAINERS: add Andy Shevchenko as reviewer for the GPIO subsystem
  gpio: sim: quietly ignore configured lines outside the bank
  gpio: sim: fix memory corruption when adding named lines and unnamed hogs

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

  Before 4.1, all ftrace tracing control files were within the debugfs
  file system, which is typically located at /sys/kernel/debug/tracing.
  For backward compatibility, when mounting the debugfs file system,
  the tracefs file system will be automatically mounted at:

  /sys/kernel/debug/tracing

A few spots in tools/virtio still refer to this older debugfs
path, so let's update them to avoid confusion.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Message-Id: <20230215223350.2658616-6-zwisler@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>

Use the right structs for PACKED or split vqs when setting and
getting the vring base.

Fixes: 4c8cf318 ("vhost: introduce vDPA-based backend")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Message-Id: <20230424225031.18947-4-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

Use the right structs for PACKED or split vqs when setting and
getting the vring base.

Fixes: 4c8cf318 ("vhost: introduce vDPA-based backend")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Message-Id: <20230424225031.18947-3-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>