[PATCH 08/12] Btrfs: Make truncate(2) more ENOSPC friendly

Yan, Zheng
2009-11-12T09:35:36Z

truncating and deleting regular file are unbound operations,
so it's not good to do them in a single transaction. This
patch makes btrfs_truncate and btrfs_delete_inode start a
new transaction after all items in a tree leaf are deleted.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
---
fs/btrfs/inode.c | 316 ++++++++++++++++++++++++++++++-------------------
fs/btrfs/relocation.c | 33 +++--
2 files changed, 212 insertions(+), 137 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f60cd94..f091a6d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2843,37 +2843,40 @@ out:
* min_type is the minimum key type to truncate down to. If set to 0, this
* will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
-noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct inode *inode,
- u64 new_size, u32 min_type)
+int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode,
+ u64 new_size, u32 min_type)
{
- int ret;
struct btrfs_path *path;
- struct btrfs_key key;
- struct btrfs_key found_key;
- u32 found_type = (u8)-1;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
+ u64 mask = root->sectorsize - 1;
+ u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int encoding;
- u64 mask = root->sectorsize - 1;
+ int ret;
+ int err = 0;
+
+ BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);

if (root->ref_cows)
btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
+
path = btrfs_alloc_path();
BUG_ON(!path);
path->reada = -1;

- /* FIXME, add redo link to tree so we don't leak on crash */
key.objectid = inode->i_ino;
key.offset = (u64)-1;
key.type = (u8)-1;
@@ -2881,17 +2884,17 @@ noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
search_again:
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
- if (ret < 0)
- goto error;
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }

if (ret > 0) {
/* there are no items in the tree for us to truncate, we're
* done
*/
- if (path->slots[0] == 0) {
- ret = 0;
- goto error;
- }
+ if (path->slots[0] == 0)
+ goto out;
path->slots[0]--;
}

@@ -2926,28 +2929,17 @@ search_again:
}
item_end--;
}
- if (item_end < new_size) {
- if (found_type == BTRFS_DIR_ITEM_KEY)
- found_type = BTRFS_INODE_ITEM_KEY;
- else if (found_type == BTRFS_EXTENT_ITEM_KEY)
- found_type = BTRFS_EXTENT_DATA_KEY;
- else if (found_type == BTRFS_EXTENT_DATA_KEY)
- found_type = BTRFS_XATTR_ITEM_KEY;
- else if (found_type == BTRFS_XATTR_ITEM_KEY)
- found_type = BTRFS_INODE_REF_KEY;
- else if (found_type)
- found_type--;
- else
+ if (found_type > min_type) {
+ del_item = 1;
+ } else {
+ if (item_end < new_size)
break;
- btrfs_set_key_type(&key, found_type);
- goto next;
+ if (found_key.offset >= new_size)
+ del_item = 1;
+ else
+ del_item = 0;
}
- if (found_key.offset >= new_size)
- del_item = 1;
- else
- del_item = 0;
found_extent = 0;
-
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
@@ -3034,42 +3026,36 @@ delete:
inode->i_ino, extent_offset);
BUG_ON(ret);
}
-next:
- if (path->slots[0] == 0) {
- if (pending_del_nr)
- goto del_pending;
- btrfs_release_path(root, path);
- if (found_type == BTRFS_INODE_ITEM_KEY)
- break;
- goto search_again;
- }

- path->slots[0]--;
- if (pending_del_nr &&
- path->slots[0] + 1 != pending_del_slot) {
- struct btrfs_key debug;
-del_pending:
- btrfs_item_key_to_cpu(path->nodes[0], &debug,
- pending_del_slot);
- ret = btrfs_del_items(trans, root, path,
- pending_del_slot,
- pending_del_nr);
- BUG_ON(ret);
- pending_del_nr = 0;
+ if (found_type == BTRFS_INODE_ITEM_KEY)
+ break;
+
+ if (path->slots[0] == 0 ||
+ path->slots[0] != pending_del_slot) {
+ if (root->ref_cows) {
+ err = -EAGAIN;
+ goto out;
+ }
+ if (pending_del_nr) {
+ ret = btrfs_del_items(trans, root, path,
+ pending_del_slot,
+ pending_del_nr);
+ BUG_ON(ret);
+ pending_del_nr = 0;
+ }
btrfs_release_path(root, path);
- if (found_type == BTRFS_INODE_ITEM_KEY)
- break;
goto search_again;
+ } else {
+ path->slots[0]--;
}
}
- ret = 0;
-error:
+out:
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
}
btrfs_free_path(path);
- return ret;
+ return err;
}

/*
@@ -3189,10 +3175,6 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
if (size <= hole_start)
return 0;

- err = btrfs_truncate_page(inode->i_mapping, inode->i_size);
- if (err)
- return err;
-
while (1) {
struct btrfs_ordered_extent *ordered;
btrfs_wait_ordered_range(inode, hole_start,
@@ -3205,9 +3187,6 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
btrfs_put_ordered_extent(ordered);
}

- trans = btrfs_start_transaction(root, 1);
- btrfs_set_trans_block_group(trans, inode);
-
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
@@ -3215,38 +3194,120 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
BUG_ON(IS_ERR(em) || !em);
last_byte = min(extent_map_end(em), block_end);
last_byte = (last_byte + mask) & ~mask;
- if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
u64 hint_byte = 0;
hole_size = last_byte - cur_offset;
- err = btrfs_drop_extents(trans, inode, cur_offset,
- cur_offset + hole_size,
- &hint_byte, 1);
- if (err)
- break;

- err = btrfs_reserve_metadata_space(root, 1);
+ err = btrfs_reserve_metadata_space(root, 2);
if (err)
break;

+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ err = btrfs_drop_extents(trans, inode, cur_offset,
+ cur_offset + hole_size,
+ &hint_byte, 1);
+ BUG_ON(err);
+
err = btrfs_insert_file_extent(trans, root,
inode->i_ino, cur_offset, 0,
0, hole_size, 0, hole_size,
0, 0, 0);
+ BUG_ON(err);
+
btrfs_drop_extent_cache(inode, hole_start,
last_byte - 1, 0);
- btrfs_unreserve_metadata_space(root, 1);
+
+ btrfs_end_transaction(trans, root);
+ btrfs_unreserve_metadata_space(root, 2);
}
free_extent_map(em);
cur_offset = last_byte;
- if (err || cur_offset >= block_end)
+ if (cur_offset >= block_end)
break;
}

- btrfs_end_transaction(trans, root);
unlock_extent(io_tree, hole_start, block_end - 1, GFP_NOFS);
return err;
}

+static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ unsigned long nr;
+ int ret;
+
+ if (attr->ia_size == inode->i_size)
+ return 0;
+
+ if (attr->ia_size > inode->i_size) {
+ unsigned long limit;
+ limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+ if (attr->ia_size > inode->i_sb->s_maxbytes)
+ return -EFBIG;
+ if (limit != RLIM_INFINITY && attr->ia_size > limit) {
+ send_sig(SIGXFSZ, current, 0);
+ return -EFBIG;
+ }
+ }
+
+ ret = btrfs_reserve_metadata_space(root, 1);
+ if (ret)
+ return ret;
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ ret = btrfs_orphan_add(trans, inode);
+ BUG_ON(ret);
+
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_unreserve_metadata_space(root, 1);
+ btrfs_btree_balance_dirty(root, nr);
+
+ if (attr->ia_size > inode->i_size) {
+ ret = btrfs_cont_expand(inode, attr->ia_size);
+ if (ret) {
+ btrfs_truncate(inode);
+ return ret;
+ }
+
+ i_size_write(inode, attr->ia_size);
+ btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ ret = btrfs_update_inode(trans, root, inode);
+ BUG_ON(ret);
+ if (inode->i_nlink > 0) {
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+ }
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+ return 0;
+ }
+
+ /*
+ * We're truncating a file that used to have good data down to
+ * zero. Make sure it gets into the ordered flush list so that
+ * any new writes get down to disk quickly.
+ */
+ if (attr->ia_size == 0)
+ BTRFS_I(inode)->ordered_data_close = 1;
+
+ /* we don't support swapfiles, so vmtruncate shouldn't fail */
+ ret = vmtruncate(inode, attr->ia_size);
+ BUG_ON(ret);
+
+ return 0;
+}
+
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
@@ -3257,23 +3318,14 @@ static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
return err;

if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
- if (attr->ia_size > inode->i_size) {
- err = btrfs_cont_expand(inode, attr->ia_size);
- if (err)
- return err;
- } else if (inode->i_size > 0 &&
- attr->ia_size == 0) {
-
- /* we're truncating a file that used to have good
- * data down to zero. Make sure it gets into
- * the ordered flush list so that any new writes
- * get down to disk quickly.
- */
- BTRFS_I(inode)->ordered_data_close = 1;
- }
+ err = btrfs_setattr_size(inode, attr);
+ if (err)
+ return err;
}
+ attr->ia_valid &= ~ATTR_SIZE;

- err = inode_setattr(inode, attr);
+ if (attr->ia_valid)
+ err = inode_setattr(inode, attr);

if (!err && ((attr->ia_valid & ATTR_MODE)))
err = btrfs_acl_chmod(inode);
@@ -3305,30 +3357,32 @@ void btrfs_delete_inode(struct inode *inode)
}

btrfs_i_size_write(inode, 0);
- trans = btrfs_join_transaction(root, 1);

- btrfs_set_trans_block_group(trans, inode);
- ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0);
- if (ret) {
- btrfs_orphan_del(NULL, inode);
- goto no_delete_lock;
- }
+ while (1) {
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);

- btrfs_orphan_del(trans, inode);
+ if (ret != -EAGAIN)
+ break;

- nr = trans->blocks_used;
- clear_inode(inode);
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ trans = NULL;
+ btrfs_btree_balance_dirty(root, nr);
+ }

- btrfs_end_transaction(trans, root);
- btrfs_btree_balance_dirty(root, nr);
- return;
+ if (ret == 0) {
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+ }

-no_delete_lock:
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root, nr);
no_delete:
clear_inode(inode);
+ return;
}

/*
@@ -5092,17 +5146,20 @@ static void btrfs_truncate(struct inode *inode)
unsigned long nr;
u64 mask = root->sectorsize - 1;

- if (!S_ISREG(inode->i_mode))
- return;
- if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ if (!S_ISREG(inode->i_mode)) {
+ WARN_ON(1);
return;
+ }

ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
if (ret)
return;
+
btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
+ btrfs_ordered_update_i_size(inode, inode->i_size, NULL);

trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);

/*
* setattr is responsible for setting the ordered_data_close flag,
@@ -5124,21 +5181,32 @@ static void btrfs_truncate(struct inode *inode)
if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
btrfs_add_ordered_operation(trans, root, inode);

- btrfs_set_trans_block_group(trans, inode);
- btrfs_i_size_write(inode, inode->i_size);
+ while (1) {
+ ret = btrfs_truncate_inode_items(trans, root, inode,
+ inode->i_size,
+ BTRFS_EXTENT_DATA_KEY);
+ if (ret != -EAGAIN)
+ break;

- ret = btrfs_orphan_add(trans, inode);
- if (ret)
- goto out;
- /* FIXME, add redo link to tree so we don't leak on crash */
- ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size,
- BTRFS_EXTENT_DATA_KEY);
- btrfs_update_inode(trans, root, inode);
+ ret = btrfs_update_inode(trans, root, inode);
+ BUG_ON(ret);
+
+ nr = trans->blocks_used;
+ btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root, nr);
+
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ }

- ret = btrfs_orphan_del(trans, inode);
+ if (ret == 0 && inode->i_nlink > 0) {
+ ret = btrfs_orphan_del(trans, inode);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);

-out:
nr = trans->blocks_used;
ret = btrfs_end_transaction_throttle(trans, root);
BUG_ON(ret);
@@ -5235,9 +5303,9 @@ void btrfs_destroy_inode(struct inode *inode)

spin_lock(&root->list_lock);
if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
- printk(KERN_ERR "BTRFS: inode %lu: inode still on the orphan"
- " list\n", inode->i_ino);
- dump_stack();
+ printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
+ inode->i_ino);
+ list_del_init(&BTRFS_I(inode)->i_orphan);
}
spin_unlock(&root->list_lock);

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 975fdd3..f2aa53d 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1561,6 +1561,20 @@ static int invalidate_extent_cache(struct btrfs_root *root,
return 0;
}

+static void put_inodes(struct list_head *list)
+{
+ struct inodevec *ivec;
+ while (!list_empty(list)) {
+ ivec = list_entry(list->next, struct inodevec, list);
+ list_del(&ivec->list);
+ while (ivec->nr > 0) {
+ ivec->nr--;
+ iput(ivec->inode[ivec->nr]);
+ }
+ kfree(ivec);
+ }
+}
+
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key)

@@ -1723,6 +1737,11 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,

btrfs_btree_balance_dirty(root, nr);

+ /*
+ * put inodes outside transaction, otherwise we may deadlock.
+ */
+ put_inodes(&inode_list);
+
if (replaced && rc->stage == UPDATE_DATA_PTRS)
invalidate_extent_cache(root, &key, &next_key);
}
@@ -1752,19 +1771,7 @@ out:

btrfs_btree_balance_dirty(root, nr);

- /*
- * put inodes while we aren't holding the tree locks
- */
- while (!list_empty(&inode_list)) {
- struct inodevec *ivec;
- ivec = list_entry(inode_list.next, struct inodevec, list);
- list_del(&ivec->list);
- while (ivec->nr > 0) {
- ivec->nr--;
- iput(ivec->inode[ivec->nr]);
- }
- kfree(ivec);
- }
+ put_inodes(&inode_list);

if (replaced && rc->stage == UPDATE_DATA_PTRS)
invalidate_extent_cache(root, &key, &next_key);
--
1.6.2.5