xfs: remove infinite loop when reserving free block pool

stable inclusion
from stable-v5.10.141
commit cb41f22df3ec7b0b4f7cd9a730a538645e324f2f
category: bugfix
bugzilla: 188251,https://gitee.com/openeuler/kernel/issues/I685FC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cb41f22df3ec7b0b4f7cd9a730a538645e324f2f



--------------------------------

commit 15f04fdc upstream.

[Added wrapper xfs_fdblocks_unavailable() for 5.10.y backport]

Infinite loops in kernel code are scary.  Calls to xfs_reserve_blocks
should be rare (people should just use the defaults!) so we really don't
need to try so hard.  Simplify the logic here by removing the infinite
loop.

Cc: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	fs/xfs/xfs_mount.h

Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
(cherry picked from commit a0a575a8)