diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_bmap_btree.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap_btree.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c index b90122de0df0..59d146696a62 100644 --- a/fs/xfs/libxfs/xfs_bmap_btree.c +++ b/fs/xfs/libxfs/xfs_bmap_btree.c @@ -571,6 +571,17 @@ xfs_bmbt_init_cursor( return cur; } +/* Calculate number of records in a block mapping btree block. */ +static inline unsigned int +xfs_bmbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_bmbt_rec_t); + return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +} + /* * Calculate number of records in a bmap btree block. */ @@ -581,10 +592,24 @@ xfs_bmbt_maxrecs( int leaf) { blocklen -= XFS_BMBT_BLOCK_LEN(mp); + return xfs_bmbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_bmbt_rec_t); - return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +/* Compute the max possible height for block mapping btrees. */ +unsigned int +xfs_bmbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_bmbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_bmbt_block_maxrecs(blocklen, false) / 2; + + /* One extra level for the inode root. */ + return xfs_btree_compute_maxlevels(minrecs, MAXEXTNUM) + 1; } /* |