The incore data fork of an inode stores the bmap btree root node as 'struct
xfs_btree_block'. However, the ondisk version of the inode stores the bmap
btree root node as a 'struct xfs_bmdr_block'.
xfs_bmap_add_attrfork_btree() checks if the btree root node fits inside the
data fork of the inode. However, it incorrectly uses 'struct xfs_btree_block'
to compute the size of the bmap btree root node. Since size of 'struct
xfs_btree_block' is larger than that of 'struct xfs_bmdr_block',
xfs_bmap_add_attrfork_btree() could end up unnecessarily demoting the current
root node as the child of newly allocated root node.
This commit optimizes space usage by modifying xfs_bmap_add_attrfork_btree()
to use 'struct xfs_bmdr_block' to check if the bmap btree root node fits
inside the data fork of the inode.
Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
---
fs/xfs/libxfs/xfs_bmap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 585f7e795023..63fcac13d29c 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -927,13 +927,16 @@ xfs_bmap_add_attrfork_btree(
xfs_inode_t *ip, /* incore inode pointer */
int *flags) /* inode logging flags */
{
+ struct xfs_btree_block *block;
xfs_btree_cur_t *cur; /* btree cursor */
int error; /* error return value */
xfs_mount_t *mp; /* file system mount struct */
int stat; /* newroot status */
mp = ip->i_mount;
- if (ip->i_df.if_broot_bytes <= XFS_IFORK_DSIZE(ip))
+ block = ip->i_df.if_broot;
+
+ if (XFS_BMAP_BMDR_SPACE(block) <= XFS_IFORK_DSIZE(ip))
*flags |= XFS_ILOG_DBROOT;
else {
cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
--
2.29.2
