return ret;
}
-static int btrfs_issue_discard(struct block_device *bdev,
- u64 start, u64 len)
+#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
+static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
+ u64 *discarded_bytes)
{
- return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
+ int j, ret = 0;
+ u64 bytes_left, end;
+ u64 aligned_start = ALIGN(start, 1 << 9);
+
+ if (WARN_ON(start != aligned_start)) {
+ len -= aligned_start - start;
+ len = round_down(len, 1 << 9);
+ start = aligned_start;
+ }
+
+ *discarded_bytes = 0;
+
+ if (!len)
+ return 0;
+
+ end = start + len;
+ bytes_left = len;
+
+ /* Skip any superblocks on this device. */
+ for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
+ u64 sb_start = btrfs_sb_offset(j);
+ u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
+ u64 size = sb_start - start;
+
+ if (!in_range(sb_start, start, bytes_left) &&
+ !in_range(sb_end, start, bytes_left) &&
+ !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
+ continue;
+
+ /*
+ * Superblock spans beginning of range. Adjust start and
+ * try again.
+ */
+ if (sb_start <= start) {
+ start += sb_end - start;
+ if (start > end) {
+ bytes_left = 0;
+ break;
+ }
+ bytes_left = end - start;
+ continue;
+ }
+
+ if (size) {
+ ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
+ GFP_NOFS, 0);
+ if (!ret)
+ *discarded_bytes += size;
+ else if (ret != -EOPNOTSUPP)
+ return ret;
+ }
+
+ start = sb_end;
+ if (start > end) {
+ bytes_left = 0;
+ break;
+ }
+ bytes_left = end - start;
+ }
+
+ if (bytes_left) {
+ ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
+ GFP_NOFS, 0);
+ if (!ret)
+ *discarded_bytes += bytes_left;
+ }
+ return ret;
}
int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
for (i = 0; i < bbio->num_stripes; i++, stripe++) {
+ u64 bytes;
if (!stripe->dev->can_discard)
continue;
ret = btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
- stripe->length);
+ stripe->length,
+ &bytes);
if (!ret)
- discarded_bytes += stripe->length;
+ discarded_bytes += bytes;
else if (ret != -EOPNOTSUPP)
break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_group_cache *block_group, *tmp;
+ struct list_head *deleted_bgs;
struct extent_io_tree *unpin;
u64 start;
u64 end;
int ret;
- if (trans->aborted)
- return 0;
-
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
unpin = &fs_info->freed_extents[1];
else
unpin = &fs_info->freed_extents[0];
- while (1) {
+ while (!trans->aborted) {
mutex_lock(&fs_info->unused_bg_unpin_mutex);
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY, NULL);
cond_resched();
}
+ /*
+ * Transaction is finished. We don't need the lock anymore. We
+ * do need to clean up the block groups in case of a transaction
+ * abort.
+ */
+ deleted_bgs = &trans->transaction->deleted_bgs;
+ list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
+ u64 trimmed = 0;
+
+ ret = -EROFS;
+ if (!trans->aborted)
+ ret = btrfs_discard_extent(root,
+ block_group->key.objectid,
+ block_group->key.offset,
+ &trimmed);
+
+ list_del_init(&block_group->bg_list);
+ btrfs_put_block_group_trimming(block_group);
+ btrfs_put_block_group(block_group);
+
+ if (ret) {
+ const char *errstr = btrfs_decode_error(ret);
+ btrfs_warn(fs_info,
+ "Discard failed while removing blockgroup: errno=%d %s\n",
+ ret, errstr);
+ }
+ }
+
return 0;
}
* currently running transaction might finish and a new one start,
* allowing for new block groups to be created that can reuse the same
* physical device locations unless we take this special care.
+ *
+ * There may also be an implicit trim operation if the file system
+ * is mounted with -odiscard. The same protections must remain
+ * in place until the extents have been discarded completely when
+ * the transaction commit has completed.
*/
remove_em = (atomic_read(&block_group->trimming) == 0);
/*
spin_lock(&fs_info->unused_bgs_lock);
while (!list_empty(&fs_info->unused_bgs)) {
u64 start, end;
+ int trimming;
block_group = list_first_entry(&fs_info->unused_bgs,
struct btrfs_block_group_cache,
spin_unlock(&block_group->lock);
spin_unlock(&space_info->lock);
+ /* DISCARD can flip during remount */
+ trimming = btrfs_test_opt(root, DISCARD);
+
+ /* Implicit trim during transaction commit. */
+ if (trimming)
+ btrfs_get_block_group_trimming(block_group);
+
/*
* Btrfs_remove_chunk will abort the transaction if things go
* horribly wrong.
*/
ret = btrfs_remove_chunk(trans, root,
block_group->key.objectid);
+
+ if (ret) {
+ if (trimming)
+ btrfs_put_block_group_trimming(block_group);
+ goto end_trans;
+ }
+
+ /*
+ * If we're not mounted with -odiscard, we can just forget
+ * about this block group. Otherwise we'll need to wait
+ * until transaction commit to do the actual discard.
+ */
+ if (trimming) {
+ WARN_ON(!list_empty(&block_group->bg_list));
+ spin_lock(&trans->transaction->deleted_bgs_lock);
+ list_move(&block_group->bg_list,
+ &trans->transaction->deleted_bgs);
+ spin_unlock(&trans->transaction->deleted_bgs_lock);
+ btrfs_get_block_group(block_group);
+ }
end_trans:
btrfs_end_transaction(trans, root);
next:
return unpin_extent_range(root, start, end, false);
}
+/*
+ * It used to be that old block groups would be left around forever.
+ * Iterating over them would be enough to trim unused space. Since we
+ * now automatically remove them, we also need to iterate over unallocated
+ * space.
+ *
+ * We don't want a transaction for this since the discard may take a
+ * substantial amount of time. We don't require that a transaction be
+ * running, but we do need to take a running transaction into account
+ * to ensure that we're not discarding chunks that were released in
+ * the current transaction.
+ *
+ * Holding the chunks lock will prevent other threads from allocating
+ * or releasing chunks, but it won't prevent a running transaction
+ * from committing and releasing the memory that the pending chunks
+ * list head uses. For that, we need to take a reference to the
+ * transaction.
+ */
+static int btrfs_trim_free_extents(struct btrfs_device *device,
+ u64 minlen, u64 *trimmed)
+{
+ u64 start = 0, len = 0;
+ int ret;
+
+ *trimmed = 0;
+
+ /* Not writeable = nothing to do. */
+ if (!device->writeable)
+ return 0;
+
+ /* No free space = nothing to do. */
+ if (device->total_bytes <= device->bytes_used)
+ return 0;
+
+ ret = 0;
+
+ while (1) {
+ struct btrfs_fs_info *fs_info = device->dev_root->fs_info;
+ struct btrfs_transaction *trans;
+ u64 bytes;
+
+ ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
+ if (ret)
+ return ret;
+
+ down_read(&fs_info->commit_root_sem);
+
+ spin_lock(&fs_info->trans_lock);
+ trans = fs_info->running_transaction;
+ if (trans)
+ atomic_inc(&trans->use_count);
+ spin_unlock(&fs_info->trans_lock);
+
+ ret = find_free_dev_extent_start(trans, device, minlen, start,
+ &start, &len);
+ if (trans)
+ btrfs_put_transaction(trans);
+
+ if (ret) {
+ up_read(&fs_info->commit_root_sem);
+ mutex_unlock(&fs_info->chunk_mutex);
+ if (ret == -ENOSPC)
+ ret = 0;
+ break;
+ }
+
+ ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
+ up_read(&fs_info->commit_root_sem);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ if (ret)
+ break;
+
+ start += len;
+ *trimmed += bytes;
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
+
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;
+ struct btrfs_device *device;
+ struct list_head *devices;
u64 group_trimmed;
u64 start;
u64 end;
cache = next_block_group(fs_info->tree_root, cache);
}
+ mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+ devices = &root->fs_info->fs_devices->alloc_list;
+ list_for_each_entry(device, devices, dev_alloc_list) {
+ ret = btrfs_trim_free_extents(device, range->minlen,
+ &group_trimmed);
+ if (ret)
+ break;
+
+ trimmed += group_trimmed;
+ }
+ mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+
range->len = trimmed;
return ret;
}
projects / karo-tx-linux.git / blobdiff