overflow: Add struct_size_t() helper

While struct_size() is normally used in situations where the structure
type already has a pointer instance, there are places where no variable
is available. In t

overflow: Add struct_size_t() helper

While struct_size() is normally used in situations where the structure
type already has a pointer instance, there are places where no variable
is available. In the past, this has been worked around by using a typed
NULL first argument, but this is a bit ugly. Add a helper to do this,
and replace the handful of instances of the code pattern with it.

Instances were found with this Coccinelle script:

@struct_size_t@
identifier STRUCT, MEMBER;
expression COUNT;
@@

- struct_size((struct STRUCT *)\(0\|NULL\),
+ struct_size_t(struct STRUCT,
MEMBER, COUNT)

Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: James Smart <james.smart@broadcom.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: HighPoint Linux Team <linux@highpoint-tech.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: Don Brace <don.brace@microchip.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: kernel test robot <lkp@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-scsi@vger.kernel.org
Cc: megaraidlinux.pdl@broadcom.com
Cc: storagedev@microchip.com
Cc: linux-xfs@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230522211810.never.421-kees@kernel.org

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xfs: implement masked btree key comparisons for _has_records scans

For keyspace fullness scans, we want to be able to mask off the parts of
the key that we don't care about. For most btree types we

xfs: implement masked btree key comparisons for _has_records scans

For keyspace fullness scans, we want to be able to mask off the parts of
the key that we don't care about. For most btree types we /do/ want the
full keyspace, but for checking that a given space usage also has a full
complement of rmapbt records (even if different/multiple owners) we need
this masking so that we only track sparseness of rm_startblock, not the
whole keyspace (which is extremely sparse).

Augment the ->diff_two_keys and ->keys_contiguous helpers to take a
third union xfs_btree_key argument, and wire up xfs_rmap_has_records to
pass this through. This third "mask" argument should contain a nonzero
value in each structure field that should be used in the key comparisons
done during the scan.

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

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xfs: replace xfs_btree_has_record with a general keyspace scanner

The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range. Unfortunately, tha

xfs: replace xfs_btree_has_record with a general keyspace scanner

The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range. Unfortunately, that's not
sufficient for scrub. We want to be able to tell if a range of keyspace
for a btree is devoid of records, is totally mapped to records, or is
somewhere in between. By forcing this to be a boolean, we conflated
sparseness and fullness, which caused scrub to return incorrect results.
Fix the API so that we can tell the caller which of those three is the
current state.

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

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xfs: refactor ->diff_two_keys callsites

Create wrapper functions around ->diff_two_keys so that we don't have to
remember what the return values mean, and adjust some of the code
comments to reflect

xfs: refactor ->diff_two_keys callsites

Create wrapper functions around ->diff_two_keys so that we don't have to
remember what the return values mean, and adjust some of the code
comments to reflect the longtime code behavior. We're going to
introduce more uses of ->diff_two_keys in the next patch, so reduce the
cognitive load for readers by doing this refactoring now.

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

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xfs: get rid of assert from xfs_btree_islastblock

xfs_btree_check_block contains debugging knobs. With XFS_DEBUG setting up,
turn on the debugging knob can trigger the assert of xfs_btree_islastbloc

xfs: get rid of assert from xfs_btree_islastblock

xfs_btree_check_block contains debugging knobs. With XFS_DEBUG setting up,
turn on the debugging knob can trigger the assert of xfs_btree_islastblock,
test script as follows:

while true
do
mount $disk $mountpoint
fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null
echo 1 > /sys/fs/xfs/sda/errortag/btree_chk_sblk
sleep 10
umount $mountpoint
done

Kick off fsstress and only *then* turn on the debugging knob. If it
happens that the knob gets turned on after the cntbt lookup succeeds
but before the call to xfs_btree_islastblock, then we *can* end up in
the situation where a previously checked btree block suddenly starts
returning EFSCORRUPTED from xfs_btree_check_block. Kaboom.

Darrick give a very detailed explanation as follows:
Looking back at commit 27d9ee577dcce, I think the point of all this was
to make sure that the cursor has actually performed a lookup, and that
the btree block at whatever level we're asking about is ok.

If the caller hasn't ever done a lookup, the bc_levels array will be
empty, so cur->bc_levels[level].bp pointer will be NULL. The call to
xfs_btree_get_block will crash anyway, so the "ASSERT(block);" part is
pointless.

If the caller did a lookup but the lookup failed due to block
corruption, the corresponding cur->bc_levels[level].bp pointer will also
be NULL, and we'll still crash. The "ASSERT(xfs_btree_check_block);"
logic is also unnecessary.

If the cursor level points to an inode root, the block buffer will be
incore, so it had better always be consistent.

If the caller ignores a failed lookup after a successful one and calls
this function, the cursor state is garbage and the assert wouldn't have
tripped anyway. So get rid of the assert.

Fixes: 27d9ee577dcc ("xfs: actually check xfs_btree_check_block return in xfs_btree_islastblock")
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

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xfs: convert btree buffer log flags to unsigned.

5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.

We also pass the fields to log to xfs_btree_offsets() as

xfs: convert btree buffer log flags to unsigned.

5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.

We also pass the fields to log to xfs_btree_offsets() as a uint32_t
all cases now. I have no idea why we made that parameter a int64_t
in the first place, but while we are fixing this up change it to
a uint32_t field, too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

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xfs: remove kmem_zone typedef

Remove these typedefs by referencing kmem_cache directly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>

xfs: use separate btree cursor cache for each btree type

Now that we have the infrastructure to track the max possible height of
each btree type, we can create a separate slab cache for cursors of e

xfs: use separate btree cursor cache for each btree type

Now that we have the infrastructure to track the max possible height of
each btree type, we can create a separate slab cache for cursors of each
type of btree. For smaller indices like the free space btrees, this
means that we can pack more cursors into a slab page, improving slab
utilization.

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

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xfs: kill XFS_BTREE_MAXLEVELS

Nobody uses this symbol anymore, so kill it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Dave

xfs: kill XFS_BTREE_MAXLEVELS

Nobody uses this symbol anymore, so kill it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: compute the maximum height of the rmap btree when reflink enabled

Instead of assuming that the hardcoded XFS_BTREE_MAXLEVELS value is big
enough to handle the maximally tall rmap btree when all

xfs: compute the maximum height of the rmap btree when reflink enabled

Instead of assuming that the hardcoded XFS_BTREE_MAXLEVELS value is big
enough to handle the maximally tall rmap btree when all blocks are in
use and maximally shared, let's compute the maximum height assuming the
rmapbt consumes as many blocks as possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: clean up xfs_btree_{calc_size,compute_maxlevels}

During review of the next patch, Dave remarked that he found these two
btree geometry calculation functions lacking in documentation and that
th

xfs: clean up xfs_btree_{calc_size,compute_maxlevels}

During review of the next patch, Dave remarked that he found these two
btree geometry calculation functions lacking in documentation and that
they performed more work than was really necessary.

These functions take the same parameters and have nearly the same logic;
the only real difference is in the return values. Reword the function
comment to make it clearer what each function does, and move them to be
adjacent to reinforce their relation.

Clean up both of them to stop opencoding the howmany functions, stop
using the uint typedefs, and make them both support computations for
more than 2^32 leaf records, since we're going to need all of the above
for files with large data forks and large rmap btrees.

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

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xfs: dynamically allocate cursors based on maxlevels

To support future btree code, we need to be able to size btree cursors
dynamically for very large btrees. Switch the maxlevels computation to
us

xfs: dynamically allocate cursors based on maxlevels

To support future btree code, we need to be able to size btree cursors
dynamically for very large btrees. Switch the maxlevels computation to
use the precomputed values in the superblock, and create cursors that
can handle a certain height. For now, we retain the btree cursor cache
that can handle up to 9-level btrees, though a subsequent patch
introduces separate caches for each btree type, where each cache's
objects will be exactly tall enough to handle the specific btree type.

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

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xfs: encode the max btree height in the cursor

Encode the maximum btree height in the cursor, since we're soon going to
allow smaller cursors for AG btrees and larger cursors for file btrees.

Signe

xfs: encode the max btree height in the cursor

Encode the maximum btree height in the cursor, since we're soon going to
allow smaller cursors for AG btrees and larger cursors for file btrees.

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

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xfs: refactor btree cursor allocation function

Refactor btree allocation to a common helper.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>

xfs: refactor btree cursor allocation function

Refactor btree allocation to a common helper.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: rearrange xfs_btree_cur fields for better packing

Reduce the size of the btree cursor structure some more by rearranging
fields to eliminate unused space. While we're at it, fix the ragged
ind

xfs: rearrange xfs_btree_cur fields for better packing

Reduce the size of the btree cursor structure some more by rearranging
fields to eliminate unused space. While we're at it, fix the ragged
indentation and a spelling error.

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

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xfs: prepare xfs_btree_cur for dynamic cursor heights

Split out the btree level information into a separate struct and put it
at the end of the cursor structure as a VLA. Files with huge data forks

xfs: prepare xfs_btree_cur for dynamic cursor heights

Split out the btree level information into a separate struct and put it
at the end of the cursor structure as a VLA. Files with huge data forks
(and in the future, the realtime rmap btree) will require the ability to
support many more levels than a per-AG btree cursor, which means that
we're going to create per-btree type cursor caches to conserve memory
for the more common case.

Note that a subsequent patch actually introduces dynamic cursor heights.
This one merely rearranges the structure to prepare for that.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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xfs: reduce the size of nr_ops for refcount btree cursors

We're never going to run more than 4 billion btree operations on a
refcount cursor, so shrink the field to an unsigned int to reduce the
str

xfs: reduce the size of nr_ops for refcount btree cursors

We're never going to run more than 4 billion btree operations on a
refcount cursor, so shrink the field to an unsigned int to reduce the
structure size. Fix whitespace alignment too.

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

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xfs: remove xfs_btree_cur.bc_blocklog

This field isn't used by anyone, so get rid of it.

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

xfs: remove xfs_btree_cur_t typedef

Get rid of this old typedef before we start changing other things.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@o

xfs: remove xfs_btree_cur_t typedef

Get rid of this old typedef before we start changing other things.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: constify btree function parameters that are not modified

Constify the rest of the btree functions that take structure and union
pointers and are not supposed to modify them.

Signed-off-by: Dar

xfs: constify btree function parameters that are not modified

Constify the rest of the btree functions that take structure and union
pointers and are not supposed to modify them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: make the start pointer passed to btree update_lastrec functions const

This btree function is called when updating a record in the rightmost
block of a btree so that we can update the AGF's long

xfs: make the start pointer passed to btree update_lastrec functions const

This btree function is called when updating a record in the rightmost
block of a btree so that we can update the AGF's longest free extent
length field. Neither parameter is supposed to be updated, so mark them
both const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: make the start pointer passed to btree alloc_block functions const

The @start pointer passed to each per-AG btree type's ->alloc_block
function isn't supposed to be modified, since it's a hint

xfs: make the start pointer passed to btree alloc_block functions const

The @start pointer passed to each per-AG btree type's ->alloc_block
function isn't supposed to be modified, since it's a hint about the
location of the btree block being split that is to be fed to the
allocator, so mark the parameter const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: make the pointer passed to btree set_root functions const

The pointer passed to each per-AG btree type's ->set_root function isn't
supposed to be modified (that function sets an external pointe

xfs: make the pointer passed to btree set_root functions const

The pointer passed to each per-AG btree type's ->set_root function isn't
supposed to be modified (that function sets an external pointer to the
root block) so mark them const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: make the keys and records passed to btree inorder functions const

The inorder functions are simple predicates, which means that they don't
modify the parameters. Mark them all const.

Signed-o

xfs: make the keys and records passed to btree inorder functions const

The inorder functions are simple predicates, which means that they don't
modify the parameters. Mark them all const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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xfs: mark the record passed into btree init_key functions as const

These functions initialize a key from a record, but they aren't supposed
to modify the record. Mark it const.

Signed-off-by: Darr

xfs: mark the record passed into btree init_key functions as const

These functions initialize a key from a record, but they aren't supposed
to modify the record. Mark it const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

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