Up until now trimming the freespace was done irrespective of what the arguments of the FITRIM ioctl were. For example fstrim's -o/-l arguments will be entirely ignored. Fix it by correctly handling those paramter. This requires breaking if the found freespace extent is after the end of the passed range as well as completing trim after trimming fstrim_range::len bytes.

Fixes: 499f377f49f0 ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Nikolay Borisov nborisov@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com ---

Hello,

Here is a backport of upstream commit c2d1b3aae33605a61cbab445d8ae1c708ccd2698 for 4.14.y. Please apply fs/btrfs/extent-tree.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 83791d13c204..54bb5d79723a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11058,9 +11058,9 @@ int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, * transaction. */ static int btrfs_trim_free_extents(struct btrfs_device *device, - u64 minlen, u64 *trimmed) + struct fstrim_range *range, u64 *trimmed) { - u64 start = 0, len = 0; + u64 start = range->start, len = 0; int ret;

*trimmed = 0; @@ -11096,8 +11096,8 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, refcount_inc(&trans->use_count); spin_unlock(&fs_info->trans_lock);

- ret = find_free_dev_extent_start(trans, device, minlen, start, - &start, &len); + ret = find_free_dev_extent_start(trans, device, range->minlen, + start, &start, &len); if (trans) btrfs_put_transaction(trans);

@@ -11109,6 +11109,16 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, break; }

+ /* If we are out of the passed range break */ + if (start > range->start + range->len - 1) { + mutex_unlock(&fs_info->chunk_mutex); + ret = 0; + break; + } + + start = max(range->start, start); + len = min(range->len, len); + ret = btrfs_issue_discard(device->bdev, start, len, &bytes); up_read(&fs_info->commit_root_sem); mutex_unlock(&fs_info->chunk_mutex); @@ -11119,6 +11129,10 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, start += len; *trimmed += bytes;

+ /* We've trimmed enough */ + if (*trimmed >= range->len) + break; + if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; @@ -11202,8 +11216,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) mutex_lock(&fs_info->fs_devices->device_list_mutex); devices = &fs_info->fs_devices->devices; list_for_each_entry(device, devices, dev_list) { - ret = btrfs_trim_free_extents(device, range->minlen, - &group_trimmed); + ret = btrfs_trim_free_extents(device, range, &group_trimmed); if (ret) { dev_failed++; dev_ret = ret;