Btrfs: fix possible ENOSPC problems with truncate

There's a problem where we don't do any space reservation for truncates, which
can cause you to OOPs because you will be allowed to go off in the weeds a bit
since we don't account for the delalloc bytes that are created as a result of
the truncate.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Josef Bacik 2009-10-13 16:46:49 -04:00 committed by Chris Mason
parent 0eda294dfc
commit 5d5e103a70

View file

@ -3032,12 +3032,22 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
if ((offset & (blocksize - 1)) == 0)
goto out;
ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
if (ret)
goto out;
ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
if (ret)
goto out;
ret = -ENOMEM;
again:
page = grab_cache_page(mapping, index);
if (!page)
if (!page) {
btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
goto out;
}
page_start = page_offset(page);
page_end = page_start + PAGE_CACHE_SIZE - 1;
@ -3070,6 +3080,10 @@ again:
goto again;
}
clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
GFP_NOFS);
ret = btrfs_set_extent_delalloc(inode, page_start, page_end);
if (ret) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
@ -3088,6 +3102,9 @@ again:
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
out_unlock:
if (ret)
btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
unlock_page(page);
page_cache_release(page);
out:
@ -3111,7 +3128,9 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
if (size <= hole_start)
return 0;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
err = btrfs_truncate_page(inode->i_mapping, inode->i_size);
if (err)
return err;
while (1) {
struct btrfs_ordered_extent *ordered;
@ -5008,7 +5027,9 @@ static void btrfs_truncate(struct inode *inode)
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
if (ret)
return;
btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
trans = btrfs_start_transaction(root, 1);