Josef Bacik
2009-Oct-13 18:45 UTC
[PATCH] 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. This patch fixes the problem. Thanks,
Signed-off-by: Josef Bacik <jbacik@redhat.com>
---
fs/btrfs/inode.c | 27 ++++++++++++++++++++++++---
1 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2720bcc..f08ee0e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3031,12 +3031,22 @@ 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;
@@ -3069,6 +3079,10 @@ 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);
@@ -3087,6 +3101,9 @@ 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:
@@ -3110,7 +3127,9 @@ 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;
@@ -5005,7 +5024,9 @@ 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);
--
1.5.4.3
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