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Btrfs: extent_map and data=ordered fixes for space balancing

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* Add an EXTENT_BOUNDARY state bit to keep the writepage code
from merging data extents that are in the process of being
relocated.  This allows us to do accounting for them properly.

* The balancing code relocates data extents indepdent of the underlying
inode.  The extent_map code was modified to properly account for
things moving around (invalidating extent_map caches in the inode).

* Don't take the drop_mutex in the create_subvol ioctl.  It isn't
required.

* Fix walking of the ordered extent list to avoid races with sys_unlink

* Change the lock ordering rules.  Transaction start goes outside
the drop_mutex.  This allows btrfs_commit_transaction to directly
drop the relocation trees.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Zheng Yan 2008-09-26 10:05:38 -04:00 committed by Chris Mason
parent e465768938
commit 5b21f2ed3f
10 changed files with 108 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
fs/btrfs/ctree.c
View File

@ -290,7 +290,6 @@ int noinline btrfs_cow_block(struct btrfs_trans_handle *trans,
struct extent_buffer **cow_ret, u64 prealloc_dest)
{
u64 search_start;
u64 header_trans;
int ret;
if (trans->transaction != root->fs_info->running_transaction) {
@ -304,9 +303,9 @@ int noinline btrfs_cow_block(struct btrfs_trans_handle *trans,
WARN_ON(1);
}
header_trans = btrfs_header_generation(buf);
spin_lock(&root->fs_info->hash_lock);
if (header_trans == trans->transid &&
if (btrfs_header_generation(buf) == trans->transid &&
btrfs_header_owner(buf) == root->root_key.objectid &&
!btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
*cow_ret = buf;
spin_unlock(&root->fs_info->hash_lock);
@ -1300,6 +1299,7 @@ again:
/* is a cow on this block not required */
spin_lock(&root->fs_info->hash_lock);
if (btrfs_header_generation(b) == trans->transid &&
btrfs_header_owner(b) == root->root_key.objectid &&
!btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
spin_unlock(&root->fs_info->hash_lock);
goto cow_done;
@ -1396,7 +1396,8 @@ cow_done:
/* this is only true while dropping a snapshot */
if (level == lowest_level) {
break;
ret = 0;
goto done;
}
blocknr = btrfs_node_blockptr(b, slot);

11
fs/btrfs/ctree.h
View File

@ -1486,6 +1486,9 @@ static inline struct dentry *fdentry(struct file *file)
/* extent-tree.c */
int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len);
int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u32 *refs);
int btrfs_update_pinned_extents(struct btrfs_root *root,
u64 bytenr, u64 num, int pin);
int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
@ -1812,6 +1815,8 @@ void btrfs_destroy_inode(struct inode *inode);
int btrfs_init_cachep(void);
void btrfs_destroy_cachep(void);
long btrfs_ioctl_trans_end(struct file *file);
struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
struct btrfs_root *root, int wait);
struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
struct btrfs_root *root);
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
@ -1824,13 +1829,17 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode);
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
void btrfs_orphan_cleanup(struct btrfs_root *root);
/* ioctl.c */
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
/* file.c */
int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync);
int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end);
int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
int skip_pinned);
int btrfs_check_file(struct btrfs_root *root, struct inode *inode);
extern struct file_operations btrfs_file_operations;
int btrfs_drop_extents(struct btrfs_trans_handle *trans,

13
fs/btrfs/extent_io.c
View File

@ -292,7 +292,7 @@ static int merge_state(struct extent_io_tree *tree,
struct extent_state *other;
struct rb_node *other_node;
if (state->state & EXTENT_IOBITS)
if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY))
return 0;
other_node = rb_prev(&state->rb_node);
@ -1070,7 +1070,8 @@ search_again:
while(1) {
state = rb_entry(node, struct extent_state, rb_node);
if (found && state->start != cur_start) {
if (found && (state->start != cur_start ||
(state->state & EXTENT_BOUNDARY))) {
goto out;
}
if (!(state->state & EXTENT_DELALLOC)) {
@ -1078,7 +1079,7 @@ search_again:
*end = state->end;
goto out;
}
if (!found) {
if (!found && !(state->state & EXTENT_BOUNDARY)) {
struct extent_state *prev_state;
struct rb_node *prev_node = node;
while(1) {
@ -1088,7 +1089,11 @@ search_again:
prev_state = rb_entry(prev_node,
struct extent_state,
rb_node);
if (!(prev_state->state & EXTENT_DELALLOC))
if ((prev_state->end + 1 != state->start) ||
!(prev_state->state & EXTENT_DELALLOC))
break;
if ((cur_start - prev_state->start) * 2 >
max_bytes)
break;
state = prev_state;
node = prev_node;

1
fs/btrfs/extent_io.h
View File

@ -15,6 +15,7 @@
#define EXTENT_BUFFER_FILLED (1 << 8)
#define EXTENT_ORDERED (1 << 9)
#define EXTENT_ORDERED_METADATA (1 << 10)
#define EXTENT_BOUNDARY (1 << 11)
#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
/*

31
fs/btrfs/file.c
View File

@ -294,7 +294,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
last_pos_in_file,
0, 0, hole_size, 0);
btrfs_drop_extent_cache(inode, last_pos_in_file,
last_pos_in_file + hole_size -1);
last_pos_in_file + hole_size - 1, 0);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
btrfs_check_file(root, inode);
}
@ -337,7 +337,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans,
inline_size -= start_pos;
err = insert_inline_extent(trans, root, inode, start_pos,
inline_size, pages, 0, num_pages);
btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1);
btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1, 0);
BUG_ON(err);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
@ -362,7 +362,8 @@ out_unlock:
return err;
}
int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
int skip_pinned)
{
struct extent_map *em;
struct extent_map *split = NULL;
@ -371,6 +372,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
u64 len = end - start + 1;
int ret;
int testend = 1;
unsigned long flags;
WARN_ON(end < start);
if (end == (u64)-1) {
@ -389,6 +391,23 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
spin_unlock(&em_tree->lock);
break;
}
flags = em->flags;
if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
spin_unlock(&em_tree->lock);
if (em->start <= start &&
(!testend || em->start + em->len >= start + len)) {
free_extent_map(em);
break;
}
if (start < em->start) {
len = em->start - start;
} else {
len = start + len - (em->start + em->len);
start = em->start + em->len;
}
free_extent_map(em);
continue;
}
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
remove_extent_mapping(em_tree, em);
@ -398,7 +417,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
split->len = start - em->start;
split->block_start = em->block_start;
split->bdev = em->bdev;
split->flags = em->flags;
split->flags = flags;
ret = add_extent_mapping(em_tree, split);
BUG_ON(ret);
free_extent_map(split);
@ -412,7 +431,7 @@ int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
split->start = start + len;
split->len = em->start + em->len - (start + len);
split->bdev = em->bdev;
split->flags = em->flags;
split->flags = flags;
split->block_start = em->block_start + diff;
@ -541,7 +560,7 @@ int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
int recow;
int ret;
btrfs_drop_extent_cache(inode, start, end - 1);
btrfs_drop_extent_cache(inode, start, end - 1, 0);
path = btrfs_alloc_path();
if (!path)

4
fs/btrfs/inode-map.c
View File

@ -117,10 +117,14 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
*objectid = last_ino;
goto found;
}
} else if (key.objectid > search_start) {
*objectid = search_start;
goto found;
}
}
if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
break;
start_found = 1;
last_ino = key.objectid + 1;
path->slots[0]++;

52
fs/btrfs/inode.c
View File

@ -135,7 +135,7 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end)
BUG_ON(num_bytes > btrfs_super_total_bytes(&root->fs_info->super_copy));
mutex_lock(&BTRFS_I(inode)->extent_mutex);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
while(num_bytes > 0) {
@ -163,7 +163,7 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end)
break;
}
btrfs_drop_extent_cache(inode, start,
start + ins.offset - 1);
start + ins.offset - 1, 0);
}
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
@ -587,7 +587,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
btrfs_drop_extent_cache(inode, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1);
ordered_extent->len - 1, 0);
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
ins.objectid = ordered_extent->start;
@ -880,7 +880,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
int ret = 0, nr_unlink = 0, nr_truncate = 0;
/* don't do orphan cleanup if the fs is readonly. */
if (root->inode->i_sb->s_flags & MS_RDONLY)
if (root->fs_info->sb->s_flags & MS_RDONLY)
return;
path = btrfs_alloc_path();
@ -892,8 +892,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
key.offset = (u64)-1;
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, root->inode);
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
@ -933,7 +931,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
inode = btrfs_iget_locked(root->inode->i_sb,
inode = btrfs_iget_locked(root->fs_info->sb,
found_key.offset, root);
if (!inode)
break;
@ -965,7 +963,9 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
* do a destroy_inode
*/
if (is_bad_inode(inode)) {
trans = btrfs_start_transaction(root, 1);
btrfs_orphan_del(trans, inode);
btrfs_end_transaction(trans, root);
iput(inode);
continue;
}
@ -988,7 +988,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
}
void btrfs_read_locked_inode(struct inode *inode)
@ -1343,8 +1342,7 @@ noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
u64 mask = root->sectorsize - 1;
if (root->ref_cows)
btrfs_drop_extent_cache(inode,
new_size & (~mask), (u64)-1);
btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
path = btrfs_alloc_path();
path->reada = -1;
BUG_ON(!path);
@ -1677,7 +1675,7 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
hole_start, 0, 0,
hole_size, 0);
btrfs_drop_extent_cache(inode, hole_start,
(u64)-1);
(u64)-1, 0);
btrfs_check_file(root, inode);
}
mutex_unlock(&BTRFS_I(inode)->extent_mutex);
@ -1843,6 +1841,24 @@ static int btrfs_find_actor(struct inode *inode, void *opaque)
args->root == BTRFS_I(inode)->root);
}
struct inode *btrfs_ilookup(struct super_block *s, u64 objectid,
struct btrfs_root *root, int wait)
{
struct inode *inode;
struct btrfs_iget_args args;
args.ino = objectid;
args.root = root;
if (wait) {
inode = ilookup5(s, objectid, btrfs_find_actor,
(void *)&args);
} else {
inode = ilookup5_nowait(s, objectid, btrfs_find_actor,
(void *)&args);
}
return inode;
}
struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
struct btrfs_root *root)
{
@ -3266,7 +3282,7 @@ void btrfs_destroy_inode(struct inode *inode)
btrfs_put_ordered_extent(ordered);
}
}
btrfs_drop_extent_cache(inode, 0, (u64)-1);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
@ -3412,16 +3428,22 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root)
{
struct list_head *head = &root->fs_info->delalloc_inodes;
struct btrfs_inode *binode;
struct inode *inode;
unsigned long flags;
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
while(!list_empty(head)) {
binode = list_entry(head->next, struct btrfs_inode,
delalloc_inodes);
atomic_inc(&binode->vfs_inode.i_count);
inode = igrab(&binode->vfs_inode);
if (!inode)
list_del_init(&binode->delalloc_inodes);
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
filemap_write_and_wait(binode->vfs_inode.i_mapping);
iput(&binode->vfs_inode);
if (inode) {
filemap_write_and_wait(inode->i_mapping);
iput(inode);
}
cond_resched();
spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
}
spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);

2
fs/btrfs/ioctl.c
View File

@ -444,12 +444,10 @@ static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
goto out;
}
mutex_lock(&root->fs_info->drop_mutex);
if (root == root->fs_info->tree_root)
ret = create_subvol(root, vol_args->name, namelen);
else
ret = create_snapshot(root, vol_args->name, namelen);
mutex_unlock(&root->fs_info->drop_mutex);
out:
kfree(vol_args);
return ret;

26
fs/btrfs/ordered-data.c
View File

@ -309,7 +309,6 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
{
struct list_head splice;
struct list_head *cur;
struct list_head *tmp;
struct btrfs_ordered_extent *ordered;
struct inode *inode;
@ -317,37 +316,38 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only)
spin_lock(&root->fs_info->ordered_extent_lock);
list_splice_init(&root->fs_info->ordered_extents, &splice);
list_for_each_safe(cur, tmp, &splice) {
while (!list_empty(&splice)) {
cur = splice.next;
ordered = list_entry(cur, struct btrfs_ordered_extent,
root_extent_list);
if (nocow_only &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
list_move(&ordered->root_extent_list,
&root->fs_info->ordered_extents);
cond_resched_lock(&root->fs_info->ordered_extent_lock);
continue;
}
list_del_init(&ordered->root_extent_list);
atomic_inc(&ordered->refs);
inode = ordered->inode;
/*
* the inode can't go away until all the pages are gone
* and the pages won't go away while there is still
* an ordered extent and the ordered extent won't go
* away until it is off this list. So, we can safely
* increment i_count here and call iput later
* the inode may be getting freed (in sys_unlink path).
*/
atomic_inc(&inode->i_count);
inode = igrab(ordered->inode);
spin_unlock(&root->fs_info->ordered_extent_lock);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
iput(inode);
if (inode) {
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
iput(inode);
} else {
btrfs_put_ordered_extent(ordered);
}
spin_lock(&root->fs_info->ordered_extent_lock);
}
list_splice_init(&splice, &root->fs_info->ordered_extents);
spin_unlock(&root->fs_info->ordered_extent_lock);
return 0;
}

8
fs/btrfs/transaction.c
View File

@ -109,6 +109,7 @@ noinline int btrfs_record_root_in_trans(struct btrfs_root *root)
spin_lock_init(&dirty->root->node_lock);
spin_lock_init(&dirty->root->list_lock);
mutex_init(&dirty->root->objectid_mutex);
mutex_init(&dirty->root->log_mutex);
INIT_LIST_HEAD(&dirty->root->dead_list);
dirty->root->node = root->commit_root;
dirty->root->commit_root = NULL;
@ -590,13 +591,14 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
root = dirty->latest_root;
atomic_inc(&root->fs_info->throttles);
mutex_lock(&root->fs_info->drop_mutex);
while(1) {
trans = btrfs_start_transaction(tree_root, 1);
mutex_lock(&root->fs_info->drop_mutex);
ret = btrfs_drop_snapshot(trans, dirty->root);
if (ret != -EAGAIN) {
break;
}
mutex_unlock(&root->fs_info->drop_mutex);
err = btrfs_update_root(trans,
tree_root,
@ -608,10 +610,8 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->drop_mutex);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
mutex_lock(&root->fs_info->drop_mutex);
}
BUG_ON(ret);
atomic_dec(&root->fs_info->throttles);
@ -689,7 +689,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
key.objectid = objectid;
key.offset = 1;
key.offset = trans->transid;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
old = btrfs_lock_root_node(root);