On Thu, Apr 26, 2018 at 07:20:26PM +0800, Eryu Guan wrote:
> I hit ENOSPC error when creating new file in a newly created ext4
> with ea_inode feature enabled, if selinux is enabled and ext4 is
> mounted without any selinux context. e.g.
>
> mkfs -t ext4 -O ea_inode -F /dev/sda5
> mount /dev/sda5 /mnt/ext4
> touch /mnt/ext4/testfile # got ENOSPC here
>
> It turns out that we run out of journal credits in
> ext4_xattr_set_handle() when creating new selinux label for the
> newly created inode.
>
> This is because that in __ext4_new_inode() we use
> __ext4_xattr_set_credits() to calculate the reserved credits for new
> xattr, with the 'is_create' argument being true, which implies less
> credits in the ea_inode case. But we calculate the required credits
> in ext4_xattr_set_handle() with 'is_create' being false, which means
> we need more credits if ea_inode feature is enabled. So we don't
> have enough credits and error out with ENOSPC.
>
> Fix it by simply calling ext4_xattr_set_handle() with XATTR_CREATE
> flag in ext4_initxattrs(), so we end up with requiring less credits
> than reserved. The semantic of XATTR_CREATE is "Perform a pure
> create, which fails if the named attribute exists already." (from
> setxattr(2)), which is fine in this case, because we only call
> ext4_initxattrs() on newly created inode.
>
> Fixes: af65207c76ce ("ext4: fix __ext4_new_inode() journal credits calculation")
> Cc: Tahsin Erdogan <tahsin@xxxxxxxxxx>
> Signed-off-by: Eryu Guan <guaneryu@xxxxxxxxx>
Thanks, applied.
- Ted
