From: Zhao Lei <zhao...@cn.fujitsu.com>
Btrfs will report NO_SPACE when we create and remove files for several times:
1: Create a single-dev btrfs fs with default option
2: Write a file into it to take up most fs space
3: Delete above file
4: Wait about 100s to let chunk removed
5: goto 2
Script is like following:
#!/bin/bash
# Recommend 1.2G space, too large disk will make test slow
DEV="/dev/sda16"
MNT="/mnt/tmp"
dev_size="$(lsblk -bn -o SIZE "$DEV")" || exit 2
file_size_m=$((dev_size * 75 / 100 / 1024 / 1024))
echo "Loop write ${file_size_m}M file on $((dev_size / 1024 / 1024))M dev"
for ((i = 0; i < 10; i++)); do umount "$MNT" 2>/dev/null; done
echo "mkfs $DEV"
mkfs.btrfs -f "$DEV" >/dev/null || exit 2
echo "mount $DEV $MNT"
mount "$DEV" "$MNT" || exit 2
for ((loop_i = 0; loop_i < 20; loop_i++)); do
echo
echo "loop $loop_i"
echo "dd file..."
cmd=(dd if=/dev/zero of="$MNT"/file0 bs=1M count="$file_size_m")
"${cmd[@]}" 2>/dev/null || {
# NO_SPACE error triggered
echo "dd failed: ${cmd[*]}"
exit 1
}
echo "rm file..."
rm -f "$MNT"/file0 || exit 2
for ((i = 0; i < 10; i++)); do
df "$MNT" | tail -1
sleep 10
done
done
Reason:
Btrfs get free disk space by calling find_free_dev_extent() when
re-create chunk for write, but current code set search_commit_root
flag in searching tree, so disk spaces which was freed from dev_tree
but not commited can not get from find_free_dev_extent(), then
btrfs report NO_SPACE on above case.
Fix:
Remove "path->search_commit_root = 1" in find_free_dev_extent().
Tested by above script, and confirmed action with many printk.
Reported-by: Tsutomu Itoh <t-i...@jp.fujitsu.com>
Signed-off-by: Zhao Lei <zhao...@cn.fujitsu.com>
---
fs/btrfs/volumes.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 50c5a87..5cd0930 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1147,7 +1147,6 @@ again:
}
path->reada = 2;
- path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = device->devid;
--
1.8.5.1
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
