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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-09-19 10:25:03 +1000 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2016-09-19 10:25:03 +1000 |
| commit | 4ed3f68792f6a9c21a290ae777565e7562a09653 (patch) | |
| tree | f44cb6765a8bb601b68b2703d9a80a14d23a0bb8 | |
| parent | a1d46cffaf40e04acb0ecab14980ece3ef1ab933 (diff) | |
| download | linux-stable-4ed3f68792f6a9c21a290ae777565e7562a09653.tar.gz linux-stable-4ed3f68792f6a9c21a290ae777565e7562a09653.tar.bz2 linux-stable-4ed3f68792f6a9c21a290ae777565e7562a09653.zip | |
xfs: create a standard btree size calculator code
Create a helper to generate AG btree height calculator functions.
This will be used (much) later when we get to the refcount btree.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree.c | 24 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree.h | 2 |
2 files changed, 26 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 7be8d9cda2b6..50cfb98719dd 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -4797,3 +4797,27 @@ xfs_btree_query_range( return xfs_btree_overlapped_query_range(cur, &low_key, &high_key, fn, priv); } + +/* + * Calculate the number of blocks needed to store a given number of records + * in a short-format (per-AG metadata) btree. + */ +xfs_extlen_t +xfs_btree_calc_size( + struct xfs_mount *mp, + uint *limits, + unsigned long long len) +{ + int level; + int maxrecs; + xfs_extlen_t rval; + + maxrecs = limits[0]; + for (level = 0, rval = 0; len > 1; level++) { + len += maxrecs - 1; + do_div(len, maxrecs); + maxrecs = limits[1]; + rval += len; + } + return rval; +} diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h index f41a4cfff740..1c148f5c5675 100644 --- a/fs/xfs/libxfs/xfs_btree.h +++ b/fs/xfs/libxfs/xfs_btree.h @@ -501,6 +501,8 @@ bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp); bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs); uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits, unsigned long len); +xfs_extlen_t xfs_btree_calc_size(struct xfs_mount *mp, uint *limits, + unsigned long long len); /* return codes */ #define XFS_BTREE_QUERY_RANGE_CONTINUE 0 /* keep iterating */ |