xfs: require a relatively recent V5 filesystem for LARP mode

While reviewing the FIEXCHANGE code in XFS, I realized that the function
that enables logged xattrs doesn't actually check that the super

xfs: require a relatively recent V5 filesystem for LARP mode

While reviewing the FIEXCHANGE code in XFS, I realized that the function
that enables logged xattrs doesn't actually check that the superblock
has a LOG_INCOMPAT feature bit field. Add a check to refuse the
operation if we don't have a V5 filesystem...

...but on second though, let's require either reflink or rmap so that we
only have to deal with LARP mode on relatively /modern/ kernel. 4.14 is
about as far back as I feel like going.

Seeing as LARP is a debugging-only option anyway, this isn't likely to
affect any real users.

Fixes: d9c61ccb3b09 ("xfs: move xfs_attr_use_log_assist out of xfs_log.c")
Really-Fixes: f3f36c893f26 ("xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferred")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>

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fs: drop unused posix acl handlers

Remove struct posix_acl_{access,default}_handler for all filesystems
that don't depend on the xattr handler in their inode->i_op->listxattr()
method in any way. Th

fs: drop unused posix acl handlers

Remove struct posix_acl_{access,default}_handler for all filesystems
that don't depend on the xattr handler in their inode->i_op->listxattr()
method in any way. There's nothing more to do than to simply remove the
handler. It's been effectively unused ever since we introduced the new
posix acl api.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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xfs: revert commit 8954c44ff477

The name passed into __xfs_xattr_put_listent is exactly namelen bytes
long and not null-terminated. Passing namelen+1 to the strscpy function

strscpy(offset, (c

xfs: revert commit 8954c44ff477

The name passed into __xfs_xattr_put_listent is exactly namelen bytes
long and not null-terminated. Passing namelen+1 to the strscpy function

strscpy(offset, (char *)name, namelen + 1);

is therefore wrong. Go back to the old code, which works fine because
strncpy won't find a null in @name and stops after namelen bytes. It
really could be a memcpy call, but it worked for years.

Reported-by: syzbot+898115bc6d7140437215@syzkaller.appspotmail.com
Fixes: 8954c44ff477 ("xfs: use strscpy() to instead of strncpy()")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

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xfs: use strscpy() to instead of strncpy()

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Xu Panda <xu.panda

xfs: use strscpy() to instead of strncpy()

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

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fs: port xattr to mnt_idmap

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 conver

fs: port xattr to mnt_idmap

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 <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

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xfs: use memcpy, not strncpy, to format the attr prefix during listxattr

When -Wstringop-truncation is enabled, the compiler complains about
truncation of the null byte at the end of the xattr name

xfs: use memcpy, not strncpy, to format the attr prefix during listxattr

When -Wstringop-truncation is enabled, the compiler complains about
truncation of the null byte at the end of the xattr name prefix. This
is intentional, since we're concatenating the two strings together and
do _not_ want a null byte in the middle of the name.

We've already ensured that the name buffer is long enough to handle
prefix and name, and the prefix_len is supposed to be the length of the
prefix string without the null byte, so use memcpy here instead.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: fix TOCTOU race involving the new logged xattrs control knob

I found a race involving the larp control knob, aka the debugging knob
that lets developers enable logging of extended attribute upd

xfs: fix TOCTOU race involving the new logged xattrs control knob

I found a race involving the larp control knob, aka the debugging knob
that lets developers enable logging of extended attribute updates:

Thread 1 Thread 2

echo 0 > /sys/fs/xfs/debug/larp
setxattr(REPLACE)
xfs_has_larp (returns false)
xfs_attr_set

echo 1 > /sys/fs/xfs/debug/larp

xfs_attr_defer_replace
xfs_attr_init_replace_state
xfs_has_larp (returns true)
xfs_attr_init_remove_state

<oops, wrong DAS state!>

This isn't a particularly severe problem right now because xattr logging
is only enabled when CONFIG_XFS_DEBUG=y, and developers *should* know
what they're doing.

However, the eventual intent is that callers should be able to ask for
the assistance of the log in persisting xattr updates. This capability
might not be required for /all/ callers, which means that dynamic
control must work correctly. Once an xattr update has decided whether
or not to use logged xattrs, it needs to stay in that mode until the end
of the operation regardless of what subsequent parallel operations might
do.

Therefore, it is an error to continue sampling xfs_globals.larp once
xfs_attr_change has made a decision about larp, and it was not correct
for me to have told Allison that ->create_intent functions can sample
the global log incompat feature bitfield to decide to elide a log item.

Instead, create a new op flag for the xfs_da_args structure, and convert
all other callers of xfs_has_larp and xfs_sb_version_haslogxattrs within
the attr update state machine to look for the operations flag.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

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xfs: move xfs_attr_use_log_assist usage out of libxfs

The LARP patchset added an awkward coupling point between libxfs and
what would be libxlog, if the XFS log were actually its own library.
Move t

xfs: move xfs_attr_use_log_assist usage out of libxfs

The LARP patchset added an awkward coupling point between libxfs and
what would be libxlog, if the XFS log were actually its own library.
Move the code that sets up logged xattr updates out of libxfs and into
xfs_xattr.c so that libxfs no longer has to know about xlog_* functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

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xfs: move xfs_attr_use_log_assist out of xfs_log.c

The LARP patchset added an awkward coupling point between libxfs and
what would be libxlog, if the XFS log were actually its own library.
Move the

xfs: move xfs_attr_use_log_assist out of xfs_log.c

The LARP patchset added an awkward coupling point between libxfs and
what would be libxlog, if the XFS log were actually its own library.
Move the code that enables logged xattr updates out of "lib"xlog and into
xfs_xattr.c so that it no longer has to know about xlog_* functions.

While we're at it, give xfs_xattr.c its own header file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

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xfs: separate out initial attr_set states

We current use XFS_DAS_UNINIT for several steps in the attr_set
state machine. We use it for setting shortform xattrs, converting
from shortform to leaf, le

xfs: separate out initial attr_set states

We current use XFS_DAS_UNINIT for several steps in the attr_set
state machine. We use it for setting shortform xattrs, converting
from shortform to leaf, leaf add, leaf-to-node and leaf add. All of
these things are essentially known before we start the state machine
iterating, so we really should separate them out:

XFS_DAS_SF_ADD:
- tries to do a shortform add
- on success -> done
- on ENOSPC converts to leaf, -> XFS_DAS_LEAF_ADD
- on error, dies.

XFS_DAS_LEAF_ADD:
- tries to do leaf add
- on success:
- inline attr -> done
- remote xattr || REPLACE -> XFS_DAS_FOUND_LBLK
- on ENOSPC converts to node, -> XFS_DAS_NODE_ADD
- on error, dies

XFS_DAS_NODE_ADD:
- tries to do node add
- on success:
- inline attr -> done
- remote xattr || REPLACE -> XFS_DAS_FOUND_NBLK
- on error, dies

This makes it easier to understand how the state machine starts
up and sets us up on the path to further state machine
simplifications.

This also converts the DAS state tracepoints to use strings rather
than numbers, as converting between enums and numbers requires
manual counting rather than just reading the name.

This also introduces a XFS_DAS_DONE state so that we can trace
successful operation completions easily.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson<allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

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xfs: prevent metadata files from being inactivated

Files containing metadata (quota records, rt bitmap and summary info)
are fully managed by the filesystem, which means that all resource
cleanup mu

xfs: prevent metadata files from being inactivated

Files containing metadata (quota records, rt bitmap and summary info)
are fully managed by the filesystem, which means that all resource
cleanup must be explicit, not automatic. This means that they should
never be subjected automatic to post-eof truncation, nor should they be
freed automatically even if the link count drops to zero.

In other words, xfs_inactive() should leave these files alone. Add the
necessary predicate functions to make this happen. This adds a second
layer of prevention for the kinds of fs corruption that was fixed by
commit f4c32e87de7d. If we ever decide to support removing metadata
files, we should make all those metadata updates explicit.

Rearrange the order of #includes to fix compiler errors, since
xfs_mount.h is supposed to be included before xfs_inode.h

Followup-to: f4c32e87de7d ("xfs: fix realtime bitmap/summary file truncation when growing rt volume")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

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xfs: remove duplicate headers

Remove duplicate headers which are included twice.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-b

xfs: remove duplicate headers

Remove duplicate headers which are included twice.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: embedded the attrlist cursor into struct xfs_attr_list_context

The attrlist cursor only exists as part of an attr list context, so
embedd the structure instead of pointing to it. Also give it

xfs: embedded the attrlist cursor into struct xfs_attr_list_context

The attrlist cursor only exists as part of an attr list context, so
embedd the structure instead of pointing to it. Also give it a proper
xfs_ prefix and remove the obsolete typedef.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: clean up the attr flag confusion

The ATTR_* flags have a long IRIX history, where they a userspace
interface, the on-disk format and an internal interface. We've split
out the on-disk interfac

xfs: clean up the attr flag confusion

The ATTR_* flags have a long IRIX history, where they a userspace
interface, the on-disk format and an internal interface. We've split
out the on-disk interface to the XFS_ATTR_* values, but despite (or
because?) of that the flag have still been a mess. Switch the
internal interface to pass the on-disk XFS_ATTR_* flags for the
namespace and the Linux XATTR_* flags for the actual flags instead.
The ATTR_* values that are actually used are move to xfs_fs.h with a
new XFS_IOC_* prefix to not conflict with the userspace version that
has the same name and must have the same value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: improve xfs_forget_acl

Move the function to xfs_acl.c and provide a proper stub for the
!CONFIG_XFS_POSIX_ACL case. Lift the flags check to the caller as it
nicely fits in there.

Signed-off-b

xfs: improve xfs_forget_acl

Move the function to xfs_acl.c and provide a proper stub for the
!CONFIG_XFS_POSIX_ACL case. Lift the flags check to the caller as it
nicely fits in there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: rename xfs_attr_list_int to xfs_attr_list

The version taking the context structure is the main interface to list
attributes, so drop the _int postfix.

Signed-off-by: Christoph Hellwig <hch@lst

xfs: rename xfs_attr_list_int to xfs_attr_list

The version taking the context structure is the main interface to list
attributes, so drop the _int postfix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: cleanup struct xfs_attr_list_context

Replace the alist char pointer with a void buffer given that different
callers use it in different ways. Use the chance to remove the typedef
and reduce th

xfs: cleanup struct xfs_attr_list_context

Replace the alist char pointer with a void buffer given that different
callers use it in different ways. Use the chance to remove the typedef
and reduce the indentation of the struct definition so that it doesn't
overflow 80 char lines all over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: remove ATTR_KERNOVAL

We can just pass down the Linux convention of a zero valuelen to just
query for the existance of an attribute to the low-level code instead.
The use in the legacy xfs_attr_

xfs: remove ATTR_KERNOVAL

We can just pass down the Linux convention of a zero valuelen to just
query for the existance of an attribute to the low-level code instead.
The use in the legacy xfs_attr_list code only used by the ioctl
interface was already dead code, as the callers check that the flag
is not present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: pass an initialized xfs_da_args to xfs_attr_get

Instead of converting from one style of arguments to another in
xfs_attr_set, pass the structure from higher up in the call chain.

Signed-off-by

xfs: pass an initialized xfs_da_args to xfs_attr_get

Instead of converting from one style of arguments to another in
xfs_attr_set, pass the structure from higher up in the call chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: pass an initialized xfs_da_args structure to xfs_attr_set

Instead of converting from one style of arguments to another in
xfs_attr_set, pass the structure from higher up in the call chain.

Sig

xfs: pass an initialized xfs_da_args structure to xfs_attr_set

Instead of converting from one style of arguments to another in
xfs_attr_set, pass the structure from higher up in the call chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: merge xfs_attr_remove into xfs_attr_set

The Linux xattr and acl APIs use a single call for set and remove.
Modify the high-level XFS API to match that and let xfs_attr_set handle
removing attri

xfs: merge xfs_attr_remove into xfs_attr_set

The Linux xattr and acl APIs use a single call for set and remove.
Modify the high-level XFS API to match that and let xfs_attr_set handle
removing attributes as well. With a little bit of reordering this
removes a lot of code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: Remove all strlen in all xfs_attr_* functions for attr names.

This helps to pre-simplify the extra handling of the null terminator in
delayed operations which use memcpy rather than strlen. La

xfs: Remove all strlen in all xfs_attr_* functions for attr names.

This helps to pre-simplify the extra handling of the null terminator in
delayed operations which use memcpy rather than strlen. Later
when we introduce parent pointers, attribute names will become binary,
so strlen will not work at all. Removing uses of strlen now will
help reduce complexities later

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: also remove cached ACLs when removing the underlying attr

We should not just invalidate the ACL when setting the underlying
attribute, but also when removing it. The ioctl interface gets that

xfs: also remove cached ACLs when removing the underlying attr

We should not just invalidate the ACL when setting the underlying
attribute, but also when removing it. The ioctl interface gets that
right, but the normal xattr inteface skipped the xfs_forget_acl due
to an early return.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

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xfs: fix missing header includes

Some of the xfs source files are missing header includes, so add them
back. Sparse complains about non-static functions that don't have a
forward declaration anywhe

xfs: fix missing header includes

Some of the xfs source files are missing header includes, so add them
back. Sparse complains about non-static functions that don't have a
forward declaration anywhere.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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