File util-linux-libblkid-reopen-floppy-without-O_NON... of Package util-linux

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File util-linux-libblkid-reopen-floppy-without-O_NONBLOCK.patch of Package util-linux (Revision a6f22bfe000e07e0691fc6a270a77779)

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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

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File util-linux-libblkid-reopen-floppy-without-O_NONBLOCK.patch of Package util-linux (Revision a6f22bfe000e07e0691fc6a270a77779)

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