From 07ed253a49cbe80c15d43ed3800206f99d15b43e Mon Sep 17 00:00:00 2001

From: Karel Zak <kzak@redhat.com>

Date: Mon, 4 Oct 2021 11:14:01 +0200

Subject: fstrim: don't trigger autofs

- ignore read-only entries

- ignore autofs entries (for example from /proc/self/mountinfo)

- ignore autofs mountpoints where automounter has not been triggered yet

Fixes: https://github.com/karelzak/util-linux/issues/1463

Signed-off-by: Karel Zak <kzak@redhat.com>

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=2165981

---

 sys-utils/fstrim.8.adoc |  2 +-

 sys-utils/fstrim.c      | 28 +++++++++++++++++++++++++++-

 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/sys-utils/fstrim.8.adoc b/sys-utils/fstrim.8.adoc

index 66671c293..d2f3b05be 100644

--- a/sys-utils/fstrim.8.adoc

+++ b/sys-utils/fstrim.8.adoc

@@ -29,7 +29,7 @@ Running *fstrim* frequently, or even using *mount -o discard*, might negatively

 The _offset_, _length_, and _minimum-size_ arguments may be followed by the multiplicative suffixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has the same meaning as "KiB") or the suffixes KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.

 *-A, --fstab*::

-Trim all mounted filesystems mentioned in _/etc/fstab_ on devices that support the discard operation. The root filesystem is determined from kernel command line if missing in the file. The other supplied options, like *--offset*, *--length* and *--minimum*, are applied to all these devices. Errors from filesystems that do not support the discard operation, read-only devices and read-only filesystems are silently ignored.

+Trim all mounted filesystems mentioned in _/etc/fstab_ on devices that support the discard operation. The root filesystem is determined from kernel command line if missing in the file. The other supplied options, like *--offset*, *--length* and *--minimum*, are applied to all these devices. Errors from filesystems that do not support the discard operation, read-only devices, autofs and read-only filesystems are silently ignored.

 *-a, --all*::

 Trim all mounted filesystems on devices that support the discard operation. The other supplied options, like *--offset*, *--length* and *--minimum*, are applied to all these devices. Errors from filesystems that do not support the discard operation, read-only devices and read-only filesystems are silently ignored.

diff --git a/sys-utils/fstrim.c b/sys-utils/fstrim.c

index d2aec4f71..ea787f42c 100644

--- a/sys-utils/fstrim.c

+++ b/sys-utils/fstrim.c

@@ -35,6 +35,7 @@

 #include <sys/ioctl.h>

 #include <sys/stat.h>

+#include <sys/vfs.h>

 #include <linux/fs.h>

 #include "nls.h"

@@ -45,6 +46,7 @@

 #include "pathnames.h"

 #include "sysfs.h"

 #include "optutils.h"

+#include "statfs_magic.h"

 #include <libmount.h>

@@ -207,6 +209,30 @@ fail:

 	return 1;

 }

+static int is_unwanted_fs(struct libmnt_fs *fs, const char *tgt)

+{

+	struct statfs vfs;

+	int fd, rc;

+

+	if (mnt_fs_is_pseudofs(fs))

+		return 1;

+	if (mnt_fs_is_netfs(fs))

+		return 1;

+	if (mnt_fs_is_swaparea(fs))

+		return 1;

+	if (mnt_fs_match_fstype(fs, "autofs"))

+		return 1;

+	if (mnt_fs_match_options(fs, "ro"))

+		return 1;

+

+	fd = open(tgt, O_PATH);

+	if (!fd)

+		return 1;

+	rc = fstatfs(fd, &vfs) != 0 || vfs.f_type == STATFS_AUTOFS_MAGIC;

+	close(fd);

+

+	return rc;

+}

 static int uniq_fs_target_cmp(

 		struct libmnt_table *tb __attribute__((__unused__)),

@@ -292,7 +318,7 @@ static int fstrim_all_from_file(struct fstrim_control *ctl, const char *filename

 		const char *src = mnt_fs_get_srcpath(fs),

 			   *tgt = mnt_fs_get_target(fs);

-		if (!tgt || mnt_fs_is_pseudofs(fs) || mnt_fs_is_netfs(fs)) {

+		if (!tgt || is_unwanted_fs(fs, tgt)) {

 			mnt_table_remove_fs(tab, fs);

 			continue;

 		}

-- 

2.39.1