| Message ID | 20210401164525.8638-1-chandanrlinux@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xfs: Use struct xfs_bmdr_block instead of struct xfs_btree_block to calculate root node size | expand |
On Thu, Apr 01, 2021 at 10:15:25PM +0530, Chandan Babu R wrote: > @@ -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; Just initializing block o nthe line it is declared would read a little easier. Other than that this looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
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);
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@gmail.com> --- fs/xfs/libxfs/xfs_bmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)