diff options
| -rw-r--r-- | fs/xfs/libxfs/xfs_ialloc_btree.c | 51 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_ialloc_btree.h | 3 |
2 files changed, 54 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c index b95aac5b5a81..aa13b468a064 100644 --- a/fs/xfs/libxfs/xfs_ialloc_btree.c +++ b/fs/xfs/libxfs/xfs_ialloc_btree.c @@ -427,3 +427,54 @@ xfs_inobt_maxrecs( return blocklen / sizeof(xfs_inobt_rec_t); return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t)); } + +/* + * Convert the inode record holemask to an inode allocation bitmap. The inode + * allocation bitmap is inode granularity and specifies whether an inode is + * physically allocated on disk (not whether the inode is considered allocated + * or free by the fs). + * + * A bit value of 1 means the inode is allocated, a value of 0 means it is free. + */ +uint64_t +xfs_inobt_irec_to_allocmask( + struct xfs_inobt_rec_incore *rec) +{ + uint64_t bitmap = 0; + uint64_t inodespbit; + int nextbit; + uint allocbitmap; + + /* + * The holemask has 16-bits for a 64 inode record. Therefore each + * holemask bit represents multiple inodes. Create a mask of bits to set + * in the allocmask for each holemask bit. + */ + inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1; + + /* + * Allocated inodes are represented by 0 bits in holemask. Invert the 0 + * bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask + * anything beyond the 16 holemask bits since this casts to a larger + * type. + */ + allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1); + + /* + * allocbitmap is the inverted holemask so every set bit represents + * allocated inodes. To expand from 16-bit holemask granularity to + * 64-bit (e.g., bit-per-inode), set inodespbit bits in the target + * bitmap for every holemask bit. + */ + nextbit = xfs_next_bit(&allocbitmap, 1, 0); + while (nextbit != -1) { + ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY)); + + bitmap |= (inodespbit << + (nextbit * XFS_INODES_PER_HOLEMASK_BIT)); + + nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1); + } + + return bitmap; +} diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h index d7ebea72c2d0..2c581ba69cde 100644 --- a/fs/xfs/libxfs/xfs_ialloc_btree.h +++ b/fs/xfs/libxfs/xfs_ialloc_btree.h @@ -62,4 +62,7 @@ extern struct xfs_btree_cur *xfs_inobt_init_cursor(struct xfs_mount *, xfs_btnum_t); extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int); +/* ir_holemask to inode allocation bitmap conversion */ +uint64_t xfs_inobt_irec_to_allocmask(struct xfs_inobt_rec_incore *); + #endif /* __XFS_IALLOC_BTREE_H__ */ |