btrfs: prop: open code btrfs_set_prop in inherit_prop [Linux 5.2]

btrfs: prop: open code btrfs_set_prop in inherit_prop [Linux 5.2]

This Linux kernel change "btrfs: prop: open code btrfs_set_prop in inherit_prop" is included in the Linux 5.2 release. This change is authored by Anand Jain <anand.jain [at] oracle.com> on Tue Apr 2 18:07:41 2019 +0800. The commit for this change in Linux stable tree is 8b4d1ef (patch).

btrfs: prop: open code btrfs_set_prop in inherit_prop

When an inode inherits property from its parent, we call btrfs_set_prop().
btrfs_set_prop() does an elaborate checks, which is not required in the
context of inheriting a property. Instead just open-code only the required
items from btrfs_set_prop() and then call btrfs_setxattr() directly. So
now the only user of btrfs_set_prop() is gone, (except for the wraper
function btrfs_set_prop_trans()).

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

There are 30 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 fs/btrfs/props.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index 722ccf6..0d1c348 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -344,20 +344,38 @@ static int inherit_props(struct btrfs_trans_handle *trans,
        if (!value)
            continue;

+       /*
+        * This is not strictly necessary as the property should be
+        * valid, but in case it isn't, don't propagate it futher.
+        */
+       ret = h->validate(value, strlen(value));
+       if (ret)
+           continue;
+
        num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
        ret = btrfs_block_rsv_add(root, trans->block_rsv,
                      num_bytes, BTRFS_RESERVE_NO_FLUSH);
        if (ret)
-           goto out;
-       ret = btrfs_set_prop(trans, inode, h->xattr_name, value,
+           return ret;
+
+       ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
                     strlen(value), 0);
+       if (!ret) {
+           ret = h->apply(inode, value, strlen(value));
+           if (ret)
+               btrfs_setxattr(trans, inode, h->xattr_name,
+                          NULL, 0, 0);
+           else
+               set_bit(BTRFS_INODE_HAS_PROPS,
+                   &BTRFS_I(inode)->runtime_flags);
+       }
+
        btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes);
        if (ret)
-           goto out;
+           return ret;
    }
-   ret = 0;
-out:
-   return ret;
+
+   return 0;
 }

 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,

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