diff options
Diffstat (limited to 'common')
| -rw-r--r-- | common/populate | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/common/populate b/common/populate index b6f510f3..144a3f51 100644 --- a/common/populate +++ b/common/populate @@ -155,6 +155,57 @@ __populate_create_attr() { done } +# Create an extended attr structure and ensure that the fork is btree format +__populate_xfs_create_btree_attr() { + local name="$1" + local isize="$2" + local dblksz="$3" + local icore_size="$(_xfs_get_inode_core_bytes $SCRATCH_MNT)" + # We need enough extents to guarantee that the attr fork is in btree + # format. Cycling the mount to use xfs_db is too slow, so watch for + # when the number of holes that we can punch in the attr fork by + # deleting remote xattrs exceeds the number of extent mappings that can + # fit in the inode core. + local max_nextents="$(((isize - icore_size) / 16))" + local nr + local i + local incr + local bigval + + # Add about one block's worth of attrs in betweeen creating punchable + # remote value blocks. + incr=$(( (dblksz / 16) / 100 * 100 )) + bigval="$(perl -e "print \"@\" x $dblksz;")" + + touch "${name}" + + # We cannot control the mapping behaviors of the attr fork leaf and + # dabtree blocks, but we do know that remote values are stored in a + # single extent, and that those mappings are removed if the xattr is + # deleted. + # + # The extended attribute structure tends to grow from offset zero + # upwards, so we try to set up a sparse attr fork mapping by + # iteratively creating at least one leaf block's worth of local attrs, + # and then one remote attr, until the number of remote xattrs exceeds + # the number of mappings that fit in the inode core... + for ((nr = 0; nr < (incr * max_nextents); nr += incr)); do + # Simulate a getfattr dump file so we can bulk-add attrs. + ( + echo "# file: ${name}"; + seq --format "user.%08g=\"abcdefgh\"" "${nr}" "$((nr + incr + 1))" + echo "user.v$(printf "%.08d" "$nr")=\"${bigval}\"" + echo + ) | setfattr --restore - + done + + # ... and in the second loop we delete all the remote attrs to + # fragment the attr fork mappings. + for ((i = 0; i < nr; i += incr)); do + setfattr -x "user.v$(printf "%.08d" "$i")" "${name}" + done +} + # Fill up some percentage of the remaining free space __populate_fill_fs() { dir="$1" @@ -327,7 +378,7 @@ _scratch_xfs_populate() { # BTREE echo "+ btree attr" - __populate_create_attr "${SCRATCH_MNT}/ATTR.FMT_BTREE" "$((64 * blksz / 40))" true + __populate_xfs_create_btree_attr "${SCRATCH_MNT}/ATTR.FMT_BTREE" "$isize" "$dblksz" # trusted namespace touch ${SCRATCH_MNT}/ATTR.TRUSTED |