Sparse inode chunks allow the traditional inode btree record format to
describe an inode chunk that is not fully allocated and/or contiguous.
Define a couple constants that set requirements for allocation and
management of such chunks. Also define a helper to easily detect sparse
inode chunks.
The granularity of a sparse chunk is defined by the the 16-bit holemask
field in the inode record. Assuming 64 inodes per full chunk, a single
holemask bit accounts for 4 inodes. The minimum allocation requirement
for a sparse inode chunk is defined as the minimum number of blocks
required to meet the 4 inode granularity.
Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_format.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 39022d9..0baad50 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -211,6 +211,11 @@ typedef __uint64_t xfs_inofree_t;
#define XFS_INOBT_ALL_FREE ((xfs_inofree_t)-1)
#define XFS_INOBT_MASK(i) ((xfs_inofree_t)1 << (i))
+#define XFS_INODES_PER_SPCHUNK \
+ (XFS_INODES_PER_CHUNK / (NBBY * sizeof(__uint16_t)))
+#define XFS_INOBT_MIN_SPCHUNKLEN(sb) \
+ (roundup(XFS_INODES_PER_SPCHUNK, sb.sb_inopblock) / sb.sb_inopblock)
+
static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
{
return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
@@ -234,6 +239,10 @@ typedef struct xfs_inobt_rec_incore {
xfs_inofree_t ir_free; /* free inode mask */
} xfs_inobt_rec_incore_t;
+static inline bool xfs_inobt_issparse(struct xfs_inobt_rec_incore *rec)
+{
+ return rec->ir_holemask == 0 ? false : true;
+}
/*
* Key structure
--
1.8.3.1
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