* supersede: Avoid a failure when writing to /dev/null in Solaris zones
@ 2020-08-23 17:38 Bruno Haible
2020-09-20 19:31 ` Bruno Haible
0 siblings, 1 reply; 3+ messages in thread
From: Bruno Haible @ 2020-08-23 17:38 UTC (permalink / raw)
To: bug-gnulib; +Cc: Jörg Sonnenberger, Thomas Klausner
Jörg Sonnenberger noticed that the new gnulib module 'supersede', when
writing to /dev/null in Solaris/Illumos zones, fails [1][2].
Per POSIX [3],
open ("/dev/null", O_TRUNC | O_WRONLY)
and
open ("/dev/null", O_CREAT | O_TRUNC | O_WRONLY)
should be equivalent. But in Solaris/Illumos zones, the second form is needed
because the first one fails with EINVAL.
Should we extend the 'open' module to cover this bug? Probably overkill,
especially since I can't see how we could test for it in an autoconf test.
Here's a workaround, specifically in the 'supersede' module.
[1] https://www.illumos.org/issues/13035
[2] https://pkgsrc.se/files.php?messageId=20200812233110.30230FB28@cvs.NetBSD.org
[3] https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/functions/open.html
2020-08-23 Bruno Haible <bruno@clisp.org>
supersede: Avoid a failure when writing to /dev/null in Solaris zones.
Reported by Jörg Sonnenberger <joerg@netbsd.org>
via Thomas Klausner <tk@giga.or.at> in
<https://pkgsrc.se/files.php?messageId=20200812233110.30230FB28@cvs.NetBSD.org>.
* lib/supersede.c (open_supersede): When opening an existing non-regular
file on Solaris, use O_CREAT although it should not be necessary.
diff --git a/lib/supersede.c b/lib/supersede.c
index 92317f2..a03cc6d 100644
--- a/lib/supersede.c
+++ b/lib/supersede.c
@@ -78,6 +78,16 @@ open_supersede (const char *filename, int flags, mode_t mode,
struct supersede_final_action *action)
{
int fd;
+ /* Extra flags for existing devices. */
+ int extra_flags =
+ #if defined __sun
+ /* open ("/dev/null", O_TRUNC | O_WRONLY) fails with error EINVAL on Solaris
+ zones. See <https://www.illumos.org/issues/13035>. As a workaround, add
+ the O_CREAT flag, although it ought not to be necessary. */
+ O_CREAT;
+ #else
+ 0;
+ #endif
if (supersede_if_exists)
{
@@ -89,7 +99,7 @@ open_supersede (const char *filename, int flags, mode_t mode,
&& ! S_ISREG (statbuf.st_mode)
/* The file exists and is possibly a character device, socket, or
something like that. */
- && ((fd = open (filename, flags, mode)) >= 0
+ && ((fd = open (filename, flags | extra_flags, mode)) >= 0
|| errno != ENOENT))
{
if (fd >= 0)
@@ -167,7 +177,7 @@ open_supersede (const char *filename, int flags, mode_t mode,
{
/* It is possibly a character device, socket, or
something like that. */
- fd = open (canon_filename, flags, mode);
+ fd = open (canon_filename, flags | extra_flags, mode);
if (fd >= 0)
{
free (canon_filename);
@@ -197,6 +207,28 @@ open_supersede (const char *filename, int flags, mode_t mode,
action->final_rename_temp = NULL;
action->final_rename_dest = NULL;
}
+ #if defined __sun
+ /* Work around <https://www.illumos.org/issues/13035>. */
+ else if (errno == EINVAL)
+ {
+ struct stat statbuf;
+
+ if (stat (filename, &statbuf) >= 0
+ && ! S_ISREG (statbuf.st_mode))
+ {
+ /* The file exists and is possibly a character device, socket,
+ or something like that. As a workaround, add the O_CREAT
+ flag, although it ought not to be necessary.*/
+ fd = open (filename, flags | extra_flags, mode);
+ if (fd >= 0)
+ {
+ /* The file exists. */
+ action->final_rename_temp = NULL;
+ action->final_rename_dest = NULL;
+ }
+ }
+ }
+ #endif
else if (errno == ENOENT)
{
/* The file does not exist. Use a temporary file. */
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: supersede: Avoid a failure when writing to /dev/null in Solaris zones
2020-08-23 17:38 supersede: Avoid a failure when writing to /dev/null in Solaris zones Bruno Haible
@ 2020-09-20 19:31 ` Bruno Haible
0 siblings, 0 replies; 3+ messages in thread
From: Bruno Haible @ 2020-09-20 19:31 UTC (permalink / raw)
To: bug-gnulib
On 2020-08-23 I did:
> 2020-08-23 Bruno Haible <bruno@clisp.org>
>
> supersede: Avoid a failure when writing to /dev/null in Solaris zones.
> Reported by Jörg Sonnenberger <joerg@netbsd.org>
> via Thomas Klausner <tk@giga.or.at> in
> <https://pkgsrc.se/files.php?messageId=20200812233110.30230FB28@cvs.NetBSD.org>.
> * lib/supersede.c (open_supersede): When opening an existing non-regular
> file on Solaris, use O_CREAT although it should not be necessary.
The same workaround is also needed on native Windows (mingw and MSVC).
2020-09-20 Bruno Haible <bruno@clisp.org>
supersede: Fix test failures on native Windows.
* lib/supersede.c (open_supersede): Handle non-regular files on native
Windows like on Solaris.
* tests/test-supersede-open.h (test_open_supersede): Use O_BINARY flag.
diff --git a/lib/supersede.c b/lib/supersede.c
index a03cc6d..a3dfa4f 100644
--- a/lib/supersede.c
+++ b/lib/supersede.c
@@ -80,10 +80,12 @@ open_supersede (const char *filename, int flags, mode_t mode,
int fd;
/* Extra flags for existing devices. */
int extra_flags =
- #if defined __sun
+ #if defined __sun || (defined _WIN32 && !defined __CYGWIN__)
/* open ("/dev/null", O_TRUNC | O_WRONLY) fails with error EINVAL on Solaris
- zones. See <https://www.illumos.org/issues/13035>. As a workaround, add
- the O_CREAT flag, although it ought not to be necessary. */
+ zones. See <https://www.illumos.org/issues/13035>.
+ Likewise for open ("NUL", O_TRUNC | O_RDWR) on native Windows.
+ As a workaround, add the O_CREAT flag, although it ought not to be
+ necessary. */
O_CREAT;
#else
0;
@@ -207,8 +209,8 @@ open_supersede (const char *filename, int flags, mode_t mode,
action->final_rename_temp = NULL;
action->final_rename_dest = NULL;
}
- #if defined __sun
- /* Work around <https://www.illumos.org/issues/13035>. */
+ #if defined __sun || (defined _WIN32 && !defined __CYGWIN__)
+ /* See the comment regarding extra_flags, above. */
else if (errno == EINVAL)
{
struct stat statbuf;
diff --git a/tests/test-supersede-open.h b/tests/test-supersede-open.h
index f3b9b15..74a56d8 100644
--- a/tests/test-supersede-open.h
+++ b/tests/test-supersede-open.h
@@ -30,7 +30,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
ASSERT (stat (filename, &statbuf) < 0);
struct supersede_final_action action;
- int fd = open_supersede (filename, O_RDWR | O_TRUNC, 0666,
+ int fd = open_supersede (filename, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -56,7 +56,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
ino_t orig_ino = statbuf.st_ino;
struct supersede_final_action action;
- int fd = open_supersede (filename, O_RDWR | O_TRUNC, 0666,
+ int fd = open_supersede (filename, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -101,7 +101,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
ASSERT (stat (DEV_NULL, &statbuf) == 0);
struct supersede_final_action action;
- int fd = open_supersede (DEV_NULL, O_RDWR | O_TRUNC, 0666,
+ int fd = open_supersede (DEV_NULL, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -125,7 +125,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
struct supersede_final_action action;
int fd =
- open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
+ open_supersede (linkname, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -180,7 +180,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
struct supersede_final_action action;
int fd =
- open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
+ open_supersede (linkname, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -209,7 +209,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
struct supersede_final_action action;
int fd =
- open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
+ open_supersede (linkname, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd >= 0);
@@ -243,7 +243,7 @@ test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
struct supersede_final_action action;
int fd =
- open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
+ open_supersede (linkname, O_RDWR | O_BINARY | O_TRUNC, 0666,
supersede_if_exists, supersede_if_does_not_exist,
&action);
ASSERT (fd < 0);
^ permalink raw reply related [flat|nested] 3+ messages in thread
* supersede: Avoid a failure when writing to /dev/null in Solaris zones
@ 2022-09-12 8:51 Bruno Haible
0 siblings, 0 replies; 3+ messages in thread
From: Bruno Haible @ 2022-09-12 8:51 UTC (permalink / raw)
To: bug-gnulib
On Solaris 11.3 (gcc211.fsffrance.org), I'm seeing a test-supersede failure.
It's much like the one seen on Solaris/Illumos and fixed through
<https://lists.gnu.org/archive/html/bug-gnulib/2020-08/msg00206.html>.
The only difference is that here, the open() call fails with error EACCES,
not EINVAL.
This patch fixes the test failure.
2022-09-12 Bruno Haible <bruno@clisp.org>
supersede: Avoid a failure when writing to /dev/null in Solaris zones.
* lib/supersede.c (open_supersede): Treat EACCES (seen on Solaris 11.3)
like EINVAL (seen on Illumos).
diff --git a/lib/supersede.c b/lib/supersede.c
index a72c4f40e8..7fbd619fde 100644
--- a/lib/supersede.c
+++ b/lib/supersede.c
@@ -83,9 +83,12 @@ open_supersede (const char *filename, int flags, mode_t mode,
/* Extra flags for existing devices. */
int extra_flags =
#if defined __sun || (defined _WIN32 && !defined __CYGWIN__)
- /* open ("/dev/null", O_TRUNC | O_WRONLY) fails with error EINVAL on Solaris
- zones. See <https://www.illumos.org/issues/13035>.
- Likewise for open ("NUL", O_TRUNC | O_RDWR) on native Windows.
+ /* open ("/dev/null", O_TRUNC | O_WRONLY) fails on Solaris zones:
+ - with error EINVAL on Illumos, see
+ <https://www.illumos.org/issues/13035>,
+ - with error EACCES on Solaris 11.3.
+ Likewise, open ("NUL", O_TRUNC | O_RDWR) fails with error EINVAL on
+ native Windows.
As a workaround, add the O_CREAT flag, although it ought not to be
necessary. */
O_CREAT;
@@ -204,7 +207,7 @@ open_supersede (const char *filename, int flags, mode_t mode,
}
#if defined __sun || (defined _WIN32 && !defined __CYGWIN__)
/* See the comment regarding extra_flags, above. */
- else if (errno == EINVAL)
+ else if (errno == EINVAL || errno == EACCES)
{
struct stat statbuf;
^ permalink raw reply related [flat|nested] 3+ messages in thread
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