This is a potentially arguable change, because it removes some
compatibility cruft that certain systems or people may have come to rely
on (either a very long time ago, or unwisely in recent times).
On the other hand, it's been literally over a decade since OpenZFS
switched to the strategy of using opaque numbered /dev/zd* device nodes,
with the canonical zvol access path being a directory tree of symlinks
created by udev rules inside /dev/zvol/*. (See #102.) Even at the time,
the /dev/* scheme was labeled as being for "compatibility".
This commit removes the second tree of symlinks located directly at
/dev/*, under the assumption that anybody with any sense has been using
the intended /dev/zvol/* path for a very very long time now.
(The more I think about this, the more I anticipate that some large
fraction of people will have been blissfully unaware that the intention
has been for them to use the /dev/zvol/* tree all along, and they will
have come to rely upon the /dev/* tree simply because it's been there
this whole time despite being a compat thing.)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Justin Gottula <justin@jgottula.com>
Closes#12303
Assignment syntax (=) can be used for the PROGRAM key. But the PROGRAM
key is really a match key, not an assign key. The internal logic used by
udev to decide whether a PROGRAM key "matched" or not (which determines
whether the remainder of the rule is evaluated) depends on whether the
operator was OP_MATCH (==) or OP_NOMATCH (!=). [1]
The man page claims that '"=", ":=", and "+=" have the same effect as
"=="' for PROGRAM keys. And, after a brief perusal, the udev source code
does seem to confirm that operators other than OP_MATCH (==) or
OP_NOMATCH (!=) are implicitly converted to OP_MATCH (==). [2] But it's
not entirely clear that this is definitely the case: anecdotal testing
seems to indicate that when OP_ASSIGN (=) is used, the program's exit
status is disregarded and the remainder of the rule is processed
regardless of whether it was, in fact, a successful exit.
The bottom line here is that, if zvol_id hits some snag and returns a
nonzero exit status, then we almost certainly do NOT want to continue on
with the rule and use whatever the stdout contents may have been to
mindlessly create /dev/zvol/* symlinks. Therefore, let's be extra-sure
and use the match (==) operator explicitly, to eliminate any possibility
that udev might do the wrong thing, and ensure that a nonzero exit
status will definitely short-circuit the rest of the rule, bypassing the
SYMLINK+= assignments.
[1]
udev,
file src/udev/udev-rules.c,
func udev_rule_apply_token_to_event,
switch case TK_M_PROGRAM if r != 0 (nonzero exit status):
return token->op == OP_NOMATCH;
switch case TK_M_PROGRAM if r == 0 (zero exit status):
return token->op == OP_MATCH;
func retval 0 => key is considered to have matched
func retval 1 => key is considered to have NOT matched
[2]
udev,
file src/udev/udev-rules.c,
func parse_token,
at func start:
bool is_match = IN_SET(op, OP_MATCH, OP_NOMATCH);
in else-if case streq(key, "PROGRAM"):
if (!is_match) op = OP_MATCH;
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Justin Gottula <justin@jgottula.com>
Closes#12302
The $tempnode substitution is so old that it's not even mentioned in the
man page anymore. It is still technically supported by udev, but with
plenty of "deprecated" comments surrounding it.
The preferred modern equivalent of $tempnode is $devnode (or
alternatively, %N).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Justin Gottula <justin@jgottula.com>
Closes#12302
This file is old as dirt. It's entirely possible that commas were
optional in udev back at that time. But they're definitely supposed to
be there nowadays.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Justin Gottula <justin@jgottula.com>
Closes#12302
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Haakan T Johansson <f96hajo@chalmers.se>
Closes#5547Closes#5543
This change moves the default install location for the zfs udev
rules from /etc/udev/ to /lib/udev/. The correct convention is
for rules provided by a package to be installed in /lib/udev/.
The /etc/udev/ directory is reserved for custom rules or local
overrides.
Additionally, this patch cleans up some abuse of the bindir install
location by adding a udevdir and udevruledir install directories.
This allows us to revert to the default bin install location. The
udev install directories can be set with the following new options.
--with-udevdir=DIR install udev helpers [EPREFIX/lib/udev]
--with-udevruledir=DIR install udev rules [UDEVDIR/rules.d]
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#356
