Btrfs: add better -ENOSPC handling
This is a step in the direction of better -ENOSPC handling. Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.
If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC. This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.
bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line.
bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point. When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter. This keeps us from
not actually being able to allocate space for any delalloc bytes.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 872f104..dc78954 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1091,19 +1091,24 @@
WARN_ON(num_pages > nrptrs);
memset(pages, 0, sizeof(struct page *) * nrptrs);
- ret = btrfs_check_free_space(root, write_bytes, 0);
+ ret = btrfs_check_data_free_space(root, inode, write_bytes);
if (ret)
goto out;
ret = prepare_pages(root, file, pages, num_pages,
pos, first_index, last_index,
write_bytes);
- if (ret)
+ if (ret) {
+ btrfs_free_reserved_data_space(root, inode,
+ write_bytes);
goto out;
+ }
ret = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, buf);
if (ret) {
+ btrfs_free_reserved_data_space(root, inode,
+ write_bytes);
btrfs_drop_pages(pages, num_pages);
goto out;
}
@@ -1111,8 +1116,11 @@
ret = dirty_and_release_pages(NULL, root, file, pages,
num_pages, pos, write_bytes);
btrfs_drop_pages(pages, num_pages);
- if (ret)
+ if (ret) {
+ btrfs_free_reserved_data_space(root, inode,
+ write_bytes);
goto out;
+ }
if (will_write) {
btrfs_fdatawrite_range(inode->i_mapping, pos,
@@ -1136,6 +1144,8 @@
}
out:
mutex_unlock(&inode->i_mutex);
+ if (ret)
+ err = ret;
out_nolock:
kfree(pages);