Btrfs: Make fallocate(2) more ENOSPC friendly

fallocate(2) may allocate large number of file extents, so it's not
good to do it in a single transaction. This patch make fallocate(2)
start a new transaction for each file extents it allocates.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Yan, Zheng 2009-11-12 09:34:52 +00:00 committed by Chris Mason
parent 2e4bfab970
commit 5a303d5d4b

View File

@ -5664,10 +5664,10 @@ out_fail:
return err;
}
static int prealloc_file_range(struct btrfs_trans_handle *trans,
struct inode *inode, u64 start, u64 end,
static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
u64 alloc_hint, int mode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 alloc_size;
@ -5678,17 +5678,23 @@ static int prealloc_file_range(struct btrfs_trans_handle *trans,
while (num_bytes > 0) {
alloc_size = min(num_bytes, root->fs_info->max_extent);
ret = btrfs_reserve_metadata_space(root, 1);
if (ret)
goto out;
ret = btrfs_reserve_extent(trans, root, alloc_size,
root->sectorsize, 0, alloc_hint,
(u64)-1, &ins, 1);
if (ret) {
WARN_ON(1);
goto out;
break;
}
ret = btrfs_reserve_metadata_space(root, 3);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid,
ins.offset);
break;
}
trans = btrfs_start_transaction(root, 1);
ret = insert_reserved_file_extent(trans, inode,
cur_offset, ins.objectid,
ins.offset, ins.offset,
@ -5697,22 +5703,25 @@ static int prealloc_file_range(struct btrfs_trans_handle *trans,
BUG_ON(ret);
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset -1, 0);
num_bytes -= ins.offset;
cur_offset += ins.offset;
alloc_hint = ins.objectid + ins.offset;
btrfs_unreserve_metadata_space(root, 1);
}
out:
if (cur_offset > start) {
inode->i_ctime = CURRENT_TIME;
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
cur_offset > i_size_read(inode))
btrfs_i_size_write(inode, cur_offset);
cur_offset > inode->i_size) {
i_size_write(inode, cur_offset);
btrfs_ordered_update_i_size(inode, cur_offset, NULL);
}
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
}
btrfs_end_transaction(trans, root);
btrfs_unreserve_metadata_space(root, 3);
}
return ret;
}
@ -5727,8 +5736,6 @@ static long btrfs_fallocate(struct inode *inode, int mode,
u64 locked_end;
u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
struct extent_map *em;
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
alloc_start = offset & ~mask;
@ -5747,9 +5754,7 @@ static long btrfs_fallocate(struct inode *inode, int mode,
goto out;
}
root = BTRFS_I(inode)->root;
ret = btrfs_check_data_free_space(root, inode,
ret = btrfs_check_data_free_space(BTRFS_I(inode)->root, inode,
alloc_end - alloc_start);
if (ret)
goto out;
@ -5758,12 +5763,6 @@ static long btrfs_fallocate(struct inode *inode, int mode,
while (1) {
struct btrfs_ordered_extent *ordered;
trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
if (!trans) {
ret = -EIO;
goto out_free;
}
/* the extent lock is ordered inside the running
* transaction
*/
@ -5777,8 +5776,6 @@ static long btrfs_fallocate(struct inode *inode, int mode,
btrfs_put_ordered_extent(ordered);
unlock_extent(&BTRFS_I(inode)->io_tree,
alloc_start, locked_end, GFP_NOFS);
btrfs_end_transaction(trans, BTRFS_I(inode)->root);
/*
* we can't wait on the range with the transaction
* running or with the extent lock held
@ -5799,9 +5796,12 @@ static long btrfs_fallocate(struct inode *inode, int mode,
BUG_ON(IS_ERR(em) || !em);
last_byte = min(extent_map_end(em), alloc_end);
last_byte = (last_byte + mask) & ~mask;
if (em->block_start == EXTENT_MAP_HOLE) {
ret = prealloc_file_range(trans, inode, cur_offset,
last_byte, alloc_hint, mode);
if (em->block_start == EXTENT_MAP_HOLE ||
(cur_offset >= inode->i_size &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
ret = prealloc_file_range(inode,
cur_offset, last_byte,
alloc_hint, mode);
if (ret < 0) {
free_extent_map(em);
break;
@ -5820,9 +5820,8 @@ static long btrfs_fallocate(struct inode *inode, int mode,
unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
GFP_NOFS);
btrfs_end_transaction(trans, BTRFS_I(inode)->root);
out_free:
btrfs_free_reserved_data_space(root, inode, alloc_end - alloc_start);
btrfs_free_reserved_data_space(BTRFS_I(inode)->root, inode,
alloc_end - alloc_start);
out:
mutex_unlock(&inode->i_mutex);
return ret;