Problems switching between xattr=dir and xattr=sa

[chrisrd]

Switching between xattr=dir and xattr=sa then updating/removing xattrs been previously set with the other xattr=[dir|sa] style causes problems.

E.g.:

#
# Start with xattr=dir
#
zfs create -o xattr=dir pool/test
touch /pool/test/foo
setfattr -n user.foo -v one /pool/test/foo
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# Switch to xattr=sa
#
zfs set xattr=sa pool/test

#
# previous xattr is still readable
#
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# Setting a different value on the old xattr is ok
#
setfattr -n user.foo -v two /pool/test/foo
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="two"

#
# Deleting the old xattr doesn't work
# (Note: normal getfattr output would be "No such attribute")
#
setfattr -x user.foo /pool/test/foo
getfattr -n user.foo /pool/test/foo
/pool/test/foo: user.foo: Invalid argument

#
# Trying to set it again also fails
#
setfattr -n user.foo -v three /pool/test/foo
setfattr: /pool/test/foo: Invalid argument

#
# Go back to xattr=dir
#
zfs set xattr=dir pool/test

#
# Reading the xattr fails
#
getfattr -n user.foo /pool/test/foo
/pool/test/foo: user.foo: Invalid argument

#
# Trying to set it again fails
#
setfattr -n user.foo -v four /pool/test/foo
setfattr: /pool/test/foo: Invalid argument

#
# Trying to delete it fails
#
# setfattr -x user.foo /pool/test/foo
setfattr: /pool/test/foo: Invalid argument

And in the other direction, i.e. xattr=sa to xattr=dir

#
# Start with xattr=sa
#
zfs create -o xattr=sa pool/test
touch /pool/test/foo
setfattr -n user.foo -v one /pool/test/foo
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# Switch to xattr=dir
#
zfs set xattr=dir pool/test

#
# previous xattr is still readable
#
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# Setting a different value on the old xattr doesn't
# complain, but also doesn't work
#
setfattr -n user.foo -v two /pool/test/foo
getfattr -n user.foo /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# And in fact we now have two copies of the old xattr??
#
getfattr -d /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"
user.foo="one"

#
# Deleting the xattr leaves one copy
#
setfattr -x user.foo /pool/test/foo
getfattr -d /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"

#
# Deleting the 2nd copy of the xattr doesn't work
#
setfattr -x user.foo /pool/test/foo
getfattr -d /pool/test/foo
getfattr: Removing leading '/' from absolute path names
# file: pool/test/foo
user.foo="one"