On Mon, Jan 03, 2022 at 09:43:11AM +0100, Karel Zak wrote: > > Hi! Are you working on this? If not I can try to make a v2. > > I had a vacation in the last 14 days; nothing is done. Go ahead if you > have time for this task. I'm going to work on something else this > week. It seems you're busy with something else ;-), so I have implemented it, but it's not tested yet. Please, please, can you review and test it with your environment? Thanks! See the patch bellow or topic/blkid-floppy branch on github. Karel >From 49be1b256ad351cde2e0cf5000c7046e7010cc02 Mon Sep 17 00:00:00 2001 From: Karel Zak <kzak@xxxxxxxxxx> Date: Mon, 17 Jan 2022 12:37:13 +0100 Subject: [PATCH] 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@xxxxxxx> Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx> Signed-off-by: Karel Zak <kzak@xxxxxxxxxx> --- include/fileutils.h | 3 +++ lib/fileutils.c | 17 +++++++++++++++++ libblkid/src/probe.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 53 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..5b15d4916 100644 --- a/lib/fileutils.c +++ b/lib/fileutils.c @@ -288,3 +288,20 @@ 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 -EINVAL; + + buf[ssz] = '\0'; + + return open(buf, flags); +} diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c index 6168370e2..d69ff530f 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); -- 2.31.1
