From 8fc059413cc1a9e4efa56e7a627ff9166c2842a4 Mon Sep 17 00:00:00 2001 From: Ziyang Zhang Date: Mon, 12 Dec 2022 13:56:45 +0800 Subject: [PATCH] common/populate: Ensure that S_IFDIR.FMT_BTREE is in btree format Sometimes "$((128 * dblksz / 40))" dirents cannot make sure that S_IFDIR.FMT_BTREE could become btree format for its DATA fork. Actually we just observed it can fail after apply our inode extent-to-btree workaround. The root cause is that the kernel may be too good at allocating consecutive blocks so that the data fork is still in extents format. Therefore instead of using a fixed number, let's make sure the number of extents is large enough than (inode size - inode core size) / sizeof(xfs_bmbt_rec_t). Reviewed-by: Zorro Lang Reviewed-by: Allison Henderson Suggested-by: "Darrick J. Wong" Signed-off-by: Gao Xiang Signed-off-by: Ziyang Zhang Signed-off-by: Zorro Lang --- common/populate | 34 +++++++++++++++++++++++++++++++++- common/xfs | 9 +++++++++ 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/common/populate b/common/populate index 6e004997..8f7f2113 100644 --- a/common/populate +++ b/common/populate @@ -71,6 +71,37 @@ __populate_create_dir() { done } +# Create a large directory and ensure that it's a btree format +__populate_xfs_create_btree_dir() { + local name="$1" + local isize="$2" + local missing="$3" + local icore_size="$(_xfs_get_inode_core_bytes $SCRATCH_MNT)" + # We need enough extents to guarantee that the data fork is in + # btree format. Cycling the mount to use xfs_db is too slow, so + # watch for when the extent count exceeds the space after the + # inode core. + local max_nextents="$(((isize - icore_size) / 16))" + local nr=0 + + mkdir -p "${name}" + while true; do + local creat=mkdir + test "$((nr % 20))" -eq 0 && creat=touch + $creat "${name}/$(printf "%.08d" "$nr")" + if [ "$((nr % 40))" -eq 0 ]; then + local nextents="$(_xfs_get_fsxattr nextents $name)" + [ $nextents -gt $max_nextents ] && break + fi + nr=$((nr+1)) + done + + test -z "${missing}" && return + seq 1 2 "${nr}" | while read d; do + rm -rf "${name}/$(printf "%.08d" "$d")" + done +} + # Add a bunch of attrs to a file __populate_create_attr() { name="$1" @@ -176,6 +207,7 @@ _scratch_xfs_populate() { blksz="$(stat -f -c '%s' "${SCRATCH_MNT}")" dblksz="$(_xfs_get_dir_blocksize "$SCRATCH_MNT")" + isize="$(_xfs_get_inode_size "$SCRATCH_MNT")" crc="$(_xfs_has_feature "$SCRATCH_MNT" crc -v)" if [ $crc -eq 1 ]; then leaf_hdr_size=64 @@ -226,7 +258,7 @@ _scratch_xfs_populate() { # - BTREE echo "+ btree dir" - __populate_create_dir "${SCRATCH_MNT}/S_IFDIR.FMT_BTREE" "$((128 * dblksz / 40))" true + __populate_xfs_create_btree_dir "${SCRATCH_MNT}/S_IFDIR.FMT_BTREE" "$isize" true # Symlinks # - FMT_LOCAL diff --git a/common/xfs b/common/xfs index 04ae121d..65a5b5b2 100644 --- a/common/xfs +++ b/common/xfs @@ -1496,6 +1496,15 @@ _require_xfsrestore_xflag() _notrun 'xfsrestore does not support -x flag.' } +# Number of bytes reserved for a full inode record, which includes the +# immediate fork areas. +_xfs_get_inode_size() +{ + local mntpoint="$1" + + $XFS_INFO_PROG "$mntpoint" | sed -n '/meta-data=.*isize/s/^.*isize=\([0-9]*\).*$/\1/p' +} + # Number of bytes reserved for only the inode record, excluding the # immediate fork areas. _xfs_get_inode_core_bytes() -- 2.39.5