From: David Sterba dsterba@suse.com
This reverts commit b327ff8a9b5767ce39db650d468fb124b48974a5.
There is currently no corresponding patch in master due to additional changes that would be significantly different from plain revert in the respective stable branch.
The range argument was not handled correctly and could cause trim to overlap allocated areas or reach beyond the end of the device. The address space that fitrim normally operates on is in logical coordinates, while the discards are done on the physical device extents. This distinction cannot be made with the current ioctl interface and caused the confusion.
The bug depends on the layout of block groups and does not always happen. The whole-fs trim (run by default by the fstrim tool) is not affected.
Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/extent-tree.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-)
--- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11057,9 +11057,9 @@ int btrfs_error_unpin_extent_range(struc * transaction. */ static int btrfs_trim_free_extents(struct btrfs_device *device, - struct fstrim_range *range, u64 *trimmed) + u64 minlen, u64 *trimmed) { - u64 start = range->start, len = 0; + u64 start = 0, len = 0; int ret;
*trimmed = 0; @@ -11095,8 +11095,8 @@ static int btrfs_trim_free_extents(struc refcount_inc(&trans->use_count); spin_unlock(&fs_info->trans_lock);
- ret = find_free_dev_extent_start(trans, device, range->minlen, - start, &start, &len); + ret = find_free_dev_extent_start(trans, device, minlen, start, + &start, &len); if (trans) btrfs_put_transaction(trans);
@@ -11108,16 +11108,6 @@ static int btrfs_trim_free_extents(struc 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); @@ -11128,10 +11118,6 @@ static int btrfs_trim_free_extents(struc start += len; *trimmed += bytes;
- /* We've trimmed enough */ - if (*trimmed >= range->len) - break; - if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; @@ -11215,7 +11201,8 @@ int btrfs_trim_fs(struct btrfs_fs_info * 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, &group_trimmed); + ret = btrfs_trim_free_extents(device, range->minlen, + &group_trimmed); if (ret) { dev_failed++; dev_ret = ret;