return ret;
}
-static noinline u32 extent_data_ref_count(struct btrfs_root *root,
- struct btrfs_path *path,
+static noinline u32 extent_data_ref_count(struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref)
{
struct btrfs_key key;
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 */
static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
+ struct btrfs_delayed_ref_node *ref;
+
if (list_empty(&head->ref_list))
return NULL;
+ /*
+ * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
+ * This is to prevent a ref count from going down to zero, which deletes
+ * the extent item from the extent tree, when there still are references
+ * to add, which would fail because they would not find the extent item.
+ */
+ list_for_each_entry(ref, &head->ref_list, list) {
+ if (ref->action == BTRFS_ADD_DELAYED_REF)
+ return ref;
+ }
+
return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node,
list);
}
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->bytes_may_use = 0;
- if (total_bytes > 0)
- found->full = 0;
- else
- found->full = 1;
+ found->full = 0;
found->force_alloc = CHUNK_ALLOC_NO_FORCE;
found->chunk_alloc = 0;
found->flush = 0;
space_info->chunk_alloc = 0;
spin_unlock(&space_info->lock);
mutex_unlock(&fs_info->chunk_mutex);
+ /*
+ * When we allocate a new chunk we reserve space in the chunk block
+ * reserve to make sure we can COW nodes/leafs in the chunk tree or
+ * add new nodes/leafs to it if we end up needing to do it when
+ * inserting the chunk item and updating device items as part of the
+ * second phase of chunk allocation, performed by
+ * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
+ * large number of new block groups to create in our transaction
+ * handle's new_bgs list to avoid exhausting the chunk block reserve
+ * in extreme cases - like having a single transaction create many new
+ * block groups when starting to write out the free space caches of all
+ * the block groups that were made dirty during the lifetime of the
+ * transaction.
+ */
+ if (trans->chunk_bytes_reserved >= (2 * 1024 * 1024ull)) {
+ btrfs_create_pending_block_groups(trans, trans->root);
+ btrfs_trans_release_chunk_metadata(trans);
+ }
return ret;
}
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;
}
} else {
if (found_extent) {
BUG_ON(is_data && refs_to_drop !=
- extent_data_ref_count(root, path, iref));
+ extent_data_ref_count(path, iref));
if (iref) {
BUG_ON(path->slots[0] != extent_slot);
} else {
/*
* finds a free extent and does all the dirty work required for allocation
- * returns the key for the extent through ins, and a tree buffer for
- * the first block of the extent through buf.
- *
* returns the tree buffer or an ERR_PTR on error.
*/
struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
}
if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
- btrfs_drop_and_free_fs_root(tree_root->fs_info, root);
+ btrfs_add_dropped_root(trans, root);
} else {
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
return flags;
}
-static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
+static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
u64 min_allocable_bytes;
int ret = -ENOSPC;
-
/*
* We need some metadata space and system metadata space for
* allocating chunks in some corner cases until we force to set
spin_lock(&cache->lock);
if (cache->ro) {
+ cache->ro++;
ret = 0;
goto out;
}
sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
min_allocable_bytes <= sinfo->total_bytes) {
sinfo->bytes_readonly += num_bytes;
- cache->ro = 1;
+ cache->ro++;
list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
ret = 0;
}
return ret;
}
-int btrfs_set_block_group_ro(struct btrfs_root *root,
+int btrfs_inc_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 alloc_flags;
int ret;
- BUG_ON(cache->ro);
-
again:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
goto out;
}
- ret = set_block_group_ro(cache, 0);
+ ret = inc_block_group_ro(cache, 0);
if (!ret)
goto out;
alloc_flags = get_alloc_profile(root, cache->space_info->flags);
CHUNK_ALLOC_FORCE);
if (ret < 0)
goto out;
- ret = set_block_group_ro(cache, 0);
+ ret = inc_block_group_ro(cache, 0);
out:
if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
alloc_flags = update_block_group_flags(root, cache->flags);
return free_bytes;
}
-void btrfs_set_block_group_rw(struct btrfs_root *root,
+void btrfs_dec_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
- num_bytes = cache->key.offset - cache->reserved - cache->pinned -
- cache->bytes_super - btrfs_block_group_used(&cache->item);
- sinfo->bytes_readonly -= num_bytes;
- cache->ro = 0;
- list_del_init(&cache->ro_list);
+ if (!--cache->ro) {
+ num_bytes = cache->key.offset - cache->reserved -
+ cache->pinned - cache->bytes_super -
+ btrfs_block_group_used(&cache->item);
+ sinfo->bytes_readonly -= num_bytes;
+ list_del_init(&cache->ro_list);
+ }
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
}
set_avail_alloc_bits(root->fs_info, cache->flags);
if (btrfs_chunk_readonly(root, cache->key.objectid)) {
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
} else if (btrfs_block_group_used(&cache->item) == 0) {
spin_lock(&info->unused_bgs_lock);
/* Should always be true but just in case. */
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_RAID0],
list)
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_SINGLE],
list)
- set_block_group_ro(cache, 1);
+ inc_block_group_ro(cache, 1);
}
init_global_block_rsv(info);
* 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);
/* We don't want to force the issue, only flip if it's ok. */
- ret = set_block_group_ro(block_group, 0);
+ ret = inc_block_group_ro(block_group, 0);
up_write(&space_info->groups_sem);
if (ret < 0) {
ret = 0;
/* 1 for btrfs_orphan_reserve_metadata() */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
ret = PTR_ERR(trans);
goto next;
}
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
- btrfs_set_block_group_rw(root, block_group);
+ btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
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 / cascardo / linux.git / blobdiff