diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc_btree.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_alloc_btree.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c index c3e262290f6f..d0a7aa4b52a8 100644 --- a/fs/xfs/libxfs/xfs_alloc_btree.c +++ b/fs/xfs/libxfs/xfs_alloc_btree.c @@ -566,6 +566,17 @@ xfs_allocbt_commit_staged_btree( } } +/* Calculate number of records in an alloc btree block. */ +static inline unsigned int +xfs_allocbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_alloc_rec_t); + return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +} + /* * Calculate number of records in an alloc btree block. */ @@ -576,10 +587,26 @@ xfs_allocbt_maxrecs( int leaf) { blocklen -= XFS_ALLOC_BLOCK_LEN(mp); + return xfs_allocbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_alloc_rec_t); - return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +/* Free space btrees are at their largest when every other block is free. */ +#define XFS_MAX_FREESP_RECORDS ((XFS_MAX_AG_BLOCKS + 1) / 2) + +/* Compute the max possible height for free space btrees. */ +unsigned int +xfs_allocbt_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_allocbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS); } /* Calculate the freespace btree size for some records. */ |