btrfs: qgroup: Return actually freed bytes for qgroup release or free data

btrfs_qgroup_release/free_data() only returns 0 or a negative error
number (ENOMEM is the only possible error).

This is normally good enough, but sometimes we need the exact byte
count it freed/released.

Change it to return actually released/freed bytenr number instead of 0
for success.
And slightly modify related extent_changeset structure, since in btrfs
one no-hole data extent won't be larger than 128M, so "unsigned int"
is large enough for the use case.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f2a6a59..b0b02c6 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4347,7 +4347,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 start, u64 len)
 
        /* Use new btrfs_qgroup_reserve_data to reserve precious data space. */
        ret = btrfs_qgroup_reserve_data(inode, start, len);
-       if (ret)
+       if (ret < 0)
                btrfs_free_reserved_data_space_noquota(inode, start, len);
        return ret;
 }

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 1e508a8..ce670d2 100644 (file)
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -209,7 +209,7 @@ struct extent_buffer {
  */
 struct extent_changeset {
        /* How many bytes are set/cleared in this operation */
-       u64 bytes_changed;
+       unsigned int bytes_changed;
 
        /* Changed ranges */
        struct ulist range_changed;

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index fc22603..475d53c 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2897,6 +2897,7 @@ static int __btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len,
                btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
                                BTRFS_I(inode)->root->objectid,
                                changeset.bytes_changed);
+       ret = changeset.bytes_changed;
 out:
        ulist_release(&changeset.range_changed);
        return ret;