File util-linux-libblkid-reopen-floppy-without-O_NONBLOCK.patch of Package util-linux.35485
From 2d24f9639917b1691266b7a82ce9273b4904c0c4 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 17 Jan 2022 12:37:13 +0100
Subject: [PATCH 1/2] libblkid: reopen floppy without O_NONBLOCK
Vladimir Sementsov-Ogievskiy wrote:
> The commit "floppy: reintroduce O_NDELAY fix" was removed from kernel,
> so we faced the bug described and discussed here:
> https://bugzilla.suse.com/show_bug.cgi?id=3D1181018
>
> Discussion in kernel list on reverting the commit:
> https://www.spinics.net/lists/stable/msg493061.html
>
> In short, I can quote Jiri Kosina's comment:
>
> opening floppy device node with O_NONBLOCK is asking for all kinds
> of trouble
>
> So opening floppy with O_NONBLOCK in blkid leads to failure of blkid,
> probable failure of mount and unpleasant error messages in dmesg (see
> also patch 02 for details).
Based on patch from Vladimir.
CC: Jiri Kosina <jkosina@suse.cz>
Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
include/fileutils.h | 3 +++
lib/fileutils.c | 19 +++++++++++++++++++
libblkid/src/probe.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+)
diff --git a/include/fileutils.h b/include/fileutils.h
index c36ce6353..8722ed59b 100644
--- a/include/fileutils.h
+++ b/include/fileutils.h
@@ -97,4 +97,7 @@ extern void ul_close_all_fds(unsigned int first, unsigned int last);
#define UL_COPY_WRITE_ERROR (-2)
int ul_copy_file(int from, int to);
+
+extern int ul_reopen(int fd, int flags);
+
#endif /* UTIL_LINUX_FILEUTILS */
diff --git a/lib/fileutils.c b/lib/fileutils.c
index 7a8fce26f..cce3e352a 100644
--- a/lib/fileutils.c
+++ b/lib/fileutils.c
@@ -288,3 +288,22 @@ int ul_copy_file(int from, int to)
return copy_file_simple(from, to);
#endif
}
+
+int ul_reopen(int fd, int flags)
+{
+ ssize_t ssz;
+ char buf[PATH_MAX];
+ char fdpath[ sizeof(_PATH_PROC_FDDIR) + sizeof(stringify_value(INT_MAX)) ];
+
+ snprintf(fdpath, sizeof(fdpath), _PATH_PROC_FDDIR "/%d", fd);
+
+ ssz = readlink(fdpath, buf, sizeof(buf) - 1);
+ if (ssz < 0)
+ return -errno;
+
+ assert(ssz > 0);
+
+ buf[ssz] = '\0';
+
+ return open(buf, flags);
+}
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 6168370e2..7fb4cf641 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -103,6 +103,9 @@
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
+#ifdef HAVE_LINUX_FD_H
+#include <linux/fd.h>
+#endif
#include <inttypes.h>
#include <stdint.h>
#include <stdarg.h>
@@ -113,6 +116,7 @@
#include "sysfs.h"
#include "strutils.h"
#include "list.h"
+#include "fileutils.h"
/*
* All supported chains
@@ -907,6 +911,35 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
if (fd < 0)
return 1;
+#ifdef FDGETFDCSTAT
+ {
+ /*
+ * Re-open without O_NONBLOCK for floppy device.
+ *
+ * Since kernel commit c7e9d0020361f4308a70cdfd6d5335e273eb8717
+ * floppy drive works bad when opened with O_NONBLOCK.
+ */
+ struct floppy_fdc_state flst;
+
+ if (ioctl(fd, FDGETFDCSTAT, &flst) >= 0) {
+ int flags = fcntl(fd, F_GETFL, 0);
+
+ if (flags < 0)
+ goto err;
+ if (flags & O_NONBLOCK) {
+ flags &= ~O_NONBLOCK;
+
+ fd = ul_reopen(fd, flags | O_CLOEXEC);
+ if (fd < 0)
+ goto err;
+
+ pr->flags |= BLKID_FL_PRIVATE_FD;
+ pr->fd = fd;
+ }
+ }
+ }
+#endif
+
#if defined(POSIX_FADV_RANDOM) && defined(HAVE_POSIX_FADVISE)
/* Disable read-ahead */
posix_fadvise(fd, 0, 0, POSIX_FADV_RANDOM);
From 7cda56ae83ee172b1728ed42ae70afadc01e3667 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Fri, 21 Jan 2022 11:21:48 +0100
Subject: [PATCH 2/2] libblkid: reset errno after failed floppy test
Signed-off-by: Karel Zak <kzak@redhat.com>
---
libblkid/src/probe.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 7fb4cf641..6443f1009 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -937,6 +937,7 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
pr->fd = fd;
}
}
+ errno = 0;
}
#endif
