Re: Bulk discard doesn't work after add/delete of devices
From: Lutz Euler <hidden>
Date: 2012-02-09 15:50:48
Hi Liu, thanks for looking into this! You wrote:
quoted hunk ↗ jump to hunk
Would you please test the following patch on your box? thanks, liubodiff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 77ea23c..b6e2c92 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c@@ -7653,9 +7653,16 @@ int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) u64 start; u64 end; u64 trimmed = 0; + u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); int ret = 0; - cache = btrfs_lookup_block_group(fs_info, range->start); + /* + * try to trim all FS space, our block group may start from non-zero. + */ + if (range->len == total_bytes) + cache = btrfs_lookup_first_block_group(fs_info, range->start); + else + cache = btrfs_lookup_block_group(fs_info, range->start); while (cache) { if (cache->key.objectid >= (range->start + range->len)) {-- 1.6.5.2
I'm sorry but that didn't help.
I applied the patch on top of v3.3-rc2-172-g23783f8 and still fstrim
says: "0 bytes were trimmed".
I left the printk's I mentioned in place. They show that now "cache"
is not 0 so the "while (cache)" loop is entered but nevertheless
"btrfs_trim_block_group" is never called. So I put in more printk's
and found that the objectid is so large that the loop is immediately
terminated (output of printk's in "//" comments below):
int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
u64 group_trimmed;
u64 start;
u64 end;
u64 trimmed = 0;
u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
int ret = 0;
// range.start = 0, .len = 160815300608, .minlen = 512
/*
* try to trim all FS space, our block group may start from non-zero.
*/
if (range->len == total_bytes)
cache = btrfs_lookup_first_block_group(fs_info, range->start);
else
cache = btrfs_lookup_block_group(fs_info, range->start);
// cache != 0
while (cache) {
// cache->key.objectid = 213702934528
if (cache->key.objectid >= (range->start + range->len)) {
btrfs_put_block_group(cache);
break;
}
// This line is not reached.
Here's the output of "btrfs fi show /dev/sda3" again:
failed to read /dev/sr0
Label: none uuid: 88af7576-3027-4a3b-a5ae-34bfd167982f
Total devices 2 FS bytes used 29.05GB
devid 4 size 74.53GB used 40.06GB path /dev/sdb1
devid 3 size 75.24GB used 40.06GB path /dev/sda3
Kind regards,
Lutz