mainline inclusion
from mainline-v5.19-rc5
commit e45d7cb2
category: bugfix
bugzilla: 187164, https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e45d7cb2356e6b59fe64da28324025cc6fcd3fbd

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

Modify xfs_ifork_ptr to return a NULL pointer if the caller asks for the
attribute fork but i_forkoff is zero.  This eliminates the ambiguity
between i_forkoff and i_af.if_present, which should make it easier to
understand the lifetime of attr forks.

While we're at it, remove the if_present checks around calls to
xfs_idestroy_fork and xfs_ifork_zap_attr since they can both handle attr
forks that have already been torn down.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

conflicts:
	fs/xfs/libxfs/xfs_attr.h
	fs/xfs/libxfs/xfs_inode_fork.c
	fs/xfs/libxfs/xfs_inode_fork.h
	fs/xfs/xfs_icache.c
	fs/xfs/xfs_inode.c
Signed-off-by: NLong Li <leo.lilong@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>