On 2023/1/11 06:49, Dave Chinner wrote:
From: Dave Chinner <dchinner@xxxxxxxxxx> The population function creates an XFS btree format directory by polling the extent count of the inode and creating new dirents until the extent count goes over the limit that pushes it into btree format. It then removes every second dirent to create empty space in the directory data to ensure that operations like metadump with obfuscation can check that they don't leak stale data from deleted dirents. Whilst this does not result in directory data blocks being freed, it does not take into account the fact that the dabtree index has half the entries removed from it and that can result in btree nodes merging and extents being freed. This causes the extent count to go down, and the inode is converted back into extent form. The population checks then fail because it should be in btree form. Fix this by counting the number of directory data extents rather than the total number of extents in the data fork. We can do this simply by using xfs_bmap and counting the number of extents returned as it does not report extents beyond EOF (which is where the dabtree is located). As the number of data blocks does not change with the dirent removal algorithm used, this will ensure that the inode data fork remains in btree format. Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> Thanks, Gao Xiang
--- common/populate | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/common/populate b/common/populate index 9b60fa5c1..7b5b16fb8 100644 --- a/common/populate +++ b/common/populate @@ -80,8 +80,11 @@ __populate_create_nfiles() { continue fi- local nextents="$(_xfs_get_fsxattr nextents $name)"- if [ "${nextents}" -gt "${max_nextents}" ]; then + # Extent count checks use data blocks only to avoid the removal + # step from removing dabtree index blocks and reducing the + # number of extents below the required threshold. + local nextents="$(xfs_bmap ${name} |grep -v hole | wc -l)" + if [ "$((nextents - 1))" -gt "${max_nextents}" ]; then echo ${d} break fi
