xfs: don't override bc_ops for staging btrees

Add a few conditionals for staging btrees to the core btree code instead
of overloading the bc_ops vector.

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

xfs: split out a btree type from the btree ops geometry flags

Two of the btree cursor flags are always used together and encode
the fundamental btree type. There currently are two such types:

1) an on-disk AG-rooted btree with 32-bit pointers
2) an on-disk inode-rooted btree with 64-bit pointers

and we're about to add:

3) an in-memory btree with 64-bit pointers

Introduce a new enum and a new type field in struct xfs_btree_geom
to encode this type directly instead of using flags and change most
code to switch on this enum.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: make the pointer lengths explicit]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: encode the btree geometry flags in the btree ops structure

Certain btree flags never change for the life of a btree cursor because
they describe the geometry of the btree itself. Encode these in the
btree ops structure and reduce the amount of code required in each btree
type's init_cursor functions. This also frees up most of the bits in
bc_flags.

A previous version of this patch also converted the open-coded flags
logic to helpers. This was removed due to the pending refactoring (that
follows this patch) to eliminate most of the state flags.

Conversion script:

sed \
-e 's/XFS_BTREE_LONG_PTRS/XFS_BTGEO_LONG_PTRS/g' \
-e 's/XFS_BTREE_ROOT_IN_INODE/XFS_BTGEO_ROOT_IN_INODE/g' \
-e 's/XFS_BTREE_LASTREC_UPDATE/XFS_BTGEO_LASTREC_UPDATE/g' \
-e 's/XFS_BTREE_OVERLAPPING/XFS_BTGEO_OVERLAPPING/g' \
-e 's/cur->bc_flags & XFS_BTGEO_/cur->bc_ops->geom_flags \& XFS_BTGEO_/g' \
-i $(git ls-files fs/xfs/*.[ch] fs/xfs/libxfs/*.[ch] fs/xfs/scrub/*.[ch])

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

xfs: repair inode fork block mapping data structures

Use the reverse-mapping btree information to rebuild an inode block map.
Update the btree bulk loading code as necessary to support inode rooted
btrees and fix some bitrot problems.

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

xfs: constrain dirty buffers while formatting a staged btree

Constrain the number of dirty buffers that are locked by the btree
staging code at any given time by establishing a threshold at which we
put them all on the delwri queue and push them to disk. This limits
memory consumption while writing out new btrees.

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

xfs: move btree bulkload record initialization to ->get_record implementations

When we're performing a bulk load of a btree, move the code that
actually stores the btree record in the new btree block out of the
generic code and into the individual ->get_record implementations.
This is preparation for being able to store multiple records with a
single indirect call.

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

xfs: remove unused fields from struct xbtree_ifakeroot

Remove these unused fields since nobody uses them. They should have
been removed years ago in a different cleanup series from Christoph
Hellwig.

Fixes: daf83964a3681 ("xfs: move the per-fork nextents fields into struct xfs_ifork")
Fixes: f7e67b20ecbbc ("xfs: move the fork format fields into struct xfs_ifork")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: xfs_btree_staging.h: delete duplicated words

Drop the repeated words "with" and "be" in comments.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: support bulk loading of staged btrees

Add a new btree function that enables us to bulk load a btree cursor.
This will be used by the upcoming online repair patches to generate new
btrees. This avoids the programmatic inefficiency of calling
xfs_btree_insert in a loop (which generates a lot of log traffic) in
favor of stamping out new btree blocks with ordered buffers, and then
committing both the new root and scheduling the removal of the old btree
blocks in a single transaction commit.

The design of this new generic code is based off the btree rebuilding
code in xfs_repair's phase 5 code, with the explicit goal of enabling us
to share that code between scrub and repair. It has the additional
feature of being able to control btree block loading factors.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: introduce fake roots for inode-rooted btrees

Create an in-core fake root for inode-rooted btree types so that callers
can generate a whole new btree using the upcoming btree bulk load
function without making the new tree accessible from the rest of the
filesystem. It is up to the individual btree type to provide a function
to create a staged cursor (presumably with the appropriate callouts to
update the fakeroot) and then commit the staged root back into the
filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: introduce fake roots for ag-rooted btrees

Create an in-core fake root for AG-rooted btree types so that callers
can generate a whole new btree using the upcoming btree bulk load
function without making the new tree accessible from the rest of the
filesystem. It is up to the individual btree type to provide a function
to create a staged cursor (presumably with the appropriate callouts to
update the fakeroot) and then commit the staged root back into the
filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>