The name in mount invocations like mount -t debugfs debugfs /sys/kernel/debug is nothing but convention and cannot be relied upon. For example, https://www.kernel.org/doc/Documentation/filesystems/debugfs.txt recommends making the name "none" instead: mount -t debugfs none /sys/kernel/debug and many existing systems use mounts named "none" or otherwise. Using `mnt_type` instead of `mnt_fsname` allows kexec to work on such systems. This fixes another instance of `poweroff` not working on kexec'ed kernels because the lack of correctly matched mount results in EFI variables not being read and propagated. Signed-off-by: Niklas Hambüchen <mail@xxxxxx> --- kexec/arch/i386/x86-linux-setup.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c index 74fb0c4..b643c8b 100644 --- a/kexec/arch/i386/x86-linux-setup.c +++ b/kexec/arch/i386/x86-linux-setup.c @@ -433,8 +433,12 @@ out: * This really only makes sense for virtual filesystems that are only expected * to be mounted once (sysfs, debugsfs, proc), as it will return the first * instance listed in /proc/mounts, falling back to mtab if absent. + * We search by type and not by name because the name can be anything; + * while setting the name equal to the mount point is common, it cannot be + * relied upon, as even kernel documentation examples recommends using + * "none" as the name e.g. for debugfs. */ -char *find_mnt_by_fsname(char *fsname) +char *find_mnt_by_type(char *type) { FILE *mtab; struct mntent *mnt; @@ -448,7 +452,7 @@ char *find_mnt_by_fsname(char *fsname) if (!mtab) return NULL; for(mnt = getmntent(mtab); mnt; mnt = getmntent(mtab)) { - if (strcmp(mnt->mnt_fsname, fsname) == 0) + if (strcmp(mnt->mnt_type, type) == 0) break; } mntdir = mnt ? strdup(mnt->mnt_dir) : NULL; @@ -463,7 +467,7 @@ static int get_bootparam(void *buf, off_t offset, size_t size) char filename[PATH_MAX]; int err, has_sysfs_params = 0; - sysfs_mnt = find_mnt_by_fsname("sysfs"); + sysfs_mnt = find_mnt_by_type("sysfs"); if (sysfs_mnt) { snprintf(filename, PATH_MAX, "%s/%s", sysfs_mnt, "kernel/boot_params/data"); @@ -474,7 +478,7 @@ static int get_bootparam(void *buf, off_t offset, size_t size) } if (!has_sysfs_params) { - debugfs_mnt = find_mnt_by_fsname("debugfs"); + debugfs_mnt = find_mnt_by_type("debugfs"); if (!debugfs_mnt) return 1; snprintf(filename, PATH_MAX, "%s/%s", debugfs_mnt, -- 2.19.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
