| Message ID | 159646191446.1784947.11228235431863356055.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | VFS: Filesystem information [ver #21] | expand |
On Mon, Aug 03, 2020 at 02:38:34PM +0100, David Howells wrote: > Add a filesystem attribute that exports a list of all the visible mounts in > a namespace, given the caller's chroot setting. The returned list is an > array of: > > struct fsinfo_mount_child { > __u64 mnt_unique_id; > __u32 mnt_id; > __u32 parent_id; > __u32 mnt_notify_sum; > __u32 sb_notify_sum; > }; > > where each element contains a once-in-a-system-lifetime unique ID, the > mount ID (which may get reused), the parent mount ID and sums of the > notification/change counters for the mount and its superblock. The change counters are currently conditional on CONFIG_MOUNT_NOTIFICATIONS. Is this is intentional? > > This works with a read lock on the namespace_sem, but ideally would do it > under the RCU read lock only. > > Signed-off-by: David Howells <dhowells@redhat.com> > --- > > fs/fsinfo.c | 1 + > fs/internal.h | 1 + > fs/namespace.c | 37 +++++++++++++++++++++++++++++++++++++ > include/uapi/linux/fsinfo.h | 4 ++++ > samples/vfs/test-fsinfo.c | 22 ++++++++++++++++++++++ > 5 files changed, 65 insertions(+) > > diff --git a/fs/fsinfo.c b/fs/fsinfo.c > index 0540cce89555..f230124ffdf5 100644 > --- a/fs/fsinfo.c > +++ b/fs/fsinfo.c > @@ -296,6 +296,7 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = { > FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT, fsinfo_generic_mount_point), > FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT_FULL, fsinfo_generic_mount_point_full), > FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_children), > + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_mount_all), > {} > }; > > diff --git a/fs/internal.h b/fs/internal.h > index cb5edcc7125a..267b4aaf0271 100644 > --- a/fs/internal.h > +++ b/fs/internal.h > @@ -102,6 +102,7 @@ extern int fsinfo_generic_mount_topology(struct path *, struct fsinfo_context *) > extern int fsinfo_generic_mount_point(struct path *, struct fsinfo_context *); > extern int fsinfo_generic_mount_point_full(struct path *, struct fsinfo_context *); > extern int fsinfo_generic_mount_children(struct path *, struct fsinfo_context *); > +extern int fsinfo_generic_mount_all(struct path *, struct fsinfo_context *); > > /* > * fs_struct.c > diff --git a/fs/namespace.c b/fs/namespace.c > index 122c12f9512b..1f2e06507244 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -4494,4 +4494,41 @@ int fsinfo_generic_mount_children(struct path *path, struct fsinfo_context *ctx) > return ctx->usage; > } > > +/* > + * Return information about all the mounts in the namespace referenced by the > + * path. > + */ > +int fsinfo_generic_mount_all(struct path *path, struct fsinfo_context *ctx) > +{ > + struct mnt_namespace *ns; > + struct mount *m, *p; > + struct path chroot; > + bool allow; > + > + m = real_mount(path->mnt); > + ns = m->mnt_ns; > + > + get_fs_root(current->fs, &chroot); > + rcu_read_lock(); > + allow = are_paths_connected(&chroot, path) || capable(CAP_SYS_ADMIN); > + rcu_read_unlock(); > + path_put(&chroot); > + if (!allow) > + return -EPERM; > + > + down_read(&namespace_sem); > + > + list_for_each_entry(p, &ns->list, mnt_list) { This is missing locking and check added by commit 9f6c61f96f2d ("proc/mounts: add cursor"). > + struct path mnt_root; > + > + mnt_root.mnt = &p->mnt; > + mnt_root.dentry = p->mnt.mnt_root; > + if (are_paths_connected(path, &mnt_root)) > + fsinfo_store_mount(ctx, p, p == m); > + } > + > + up_read(&namespace_sem); > + return ctx->usage; > +} > + > #endif /* CONFIG_FSINFO */ > diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h > index 81329de6905e..e40192d98648 100644 > --- a/include/uapi/linux/fsinfo.h > +++ b/include/uapi/linux/fsinfo.h > @@ -37,6 +37,7 @@ > #define FSINFO_ATTR_MOUNT_POINT_FULL 0x203 /* Absolute path of mount (string) */ > #define FSINFO_ATTR_MOUNT_TOPOLOGY 0x204 /* Mount object topology */ > #define FSINFO_ATTR_MOUNT_CHILDREN 0x205 /* Children of this mount (list) */ > +#define FSINFO_ATTR_MOUNT_ALL 0x206 /* List all mounts in a namespace (list) */ > > #define FSINFO_ATTR_AFS_CELL_NAME 0x300 /* AFS cell name (string) */ > #define FSINFO_ATTR_AFS_SERVER_NAME 0x301 /* Name of the Nth server (string) */ > @@ -128,6 +129,8 @@ struct fsinfo_mount_topology { > /* > * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_CHILDREN). > * - An extra element is placed on the end representing the parent mount. > + * > + * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_ALL). > */ > struct fsinfo_mount_child { > __u64 mnt_unique_id; /* Kernel-lifetime unique mount ID */ > @@ -139,6 +142,7 @@ struct fsinfo_mount_child { > }; > > #define FSINFO_ATTR_MOUNT_CHILDREN__STRUCT struct fsinfo_mount_child > +#define FSINFO_ATTR_MOUNT_ALL__STRUCT struct fsinfo_mount_child > > /* > * Information struct for fsinfo(FSINFO_ATTR_STATFS). > diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c > index 374825ab85b0..596fa5e71762 100644 > --- a/samples/vfs/test-fsinfo.c > +++ b/samples/vfs/test-fsinfo.c > @@ -365,6 +365,27 @@ static void dump_fsinfo_generic_mount_children(void *reply, unsigned int size) > (unsigned long long)r->mnt_notify_sum, mp); > } > > +static void dump_fsinfo_generic_mount_all(void *reply, unsigned int size) > +{ > + struct fsinfo_mount_child *r = reply; > + ssize_t mplen; > + char path[32], *mp; > + > + struct fsinfo_params params = { > + .flags = FSINFO_FLAGS_QUERY_MOUNT, > + .request = FSINFO_ATTR_MOUNT_POINT_FULL, > + }; > + > + sprintf(path, "%u", r->mnt_id); > + mplen = get_fsinfo(path, "FSINFO_ATTR_MOUNT_POINT_FULL", ¶ms, (void **)&mp); > + if (mplen < 0) > + mp = "-"; > + > + printf("%5x %5x %12llx %10llu %s\n", > + r->mnt_id, r->parent_id, (unsigned long long)r->mnt_unique_id, > + r->mnt_notify_sum, mp); > +} > + > static void dump_afs_fsinfo_server_address(void *reply, unsigned int size) > { > struct fsinfo_afs_server_address *f = reply; > @@ -492,6 +513,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { > FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT, string), > FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT_FULL, string), > FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_children), > + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_mount_all), > > FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, string), > FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, string), > >
On Tue, 2020-08-04 at 16:05 +0200, Miklos Szeredi wrote: > On Mon, Aug 03, 2020 at 02:38:34PM +0100, David Howells wrote: > > Add a filesystem attribute that exports a list of all the visible > > mounts in > > a namespace, given the caller's chroot setting. The returned list > > is an > > array of: > > > > struct fsinfo_mount_child { > > __u64 mnt_unique_id; > > __u32 mnt_id; > > __u32 parent_id; > > __u32 mnt_notify_sum; > > __u32 sb_notify_sum; > > }; > > > > where each element contains a once-in-a-system-lifetime unique ID, > > the > > mount ID (which may get reused), the parent mount ID and sums of > > the > > notification/change counters for the mount and its superblock. > > The change counters are currently conditional on > CONFIG_MOUNT_NOTIFICATIONS. > Is this is intentional? > > > This works with a read lock on the namespace_sem, but ideally would > > do it > > under the RCU read lock only. > > > > Signed-off-by: David Howells <dhowells@redhat.com> > > --- > > > > fs/fsinfo.c | 1 + > > fs/internal.h | 1 + > > fs/namespace.c | 37 > > +++++++++++++++++++++++++++++++++++++ > > include/uapi/linux/fsinfo.h | 4 ++++ > > samples/vfs/test-fsinfo.c | 22 ++++++++++++++++++++++ > > 5 files changed, 65 insertions(+) > > > > diff --git a/fs/fsinfo.c b/fs/fsinfo.c > > index 0540cce89555..f230124ffdf5 100644 > > --- a/fs/fsinfo.c > > +++ b/fs/fsinfo.c > > @@ -296,6 +296,7 @@ static const struct fsinfo_attribute > > fsinfo_common_attributes[] = { > > FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT, fsinfo_gene > > ric_mount_point), > > FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT_FULL, fsinfo_gene > > ric_mount_point_full), > > FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_moun > > t_children), > > + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_moun > > t_all), > > {} > > }; > > > > diff --git a/fs/internal.h b/fs/internal.h > > index cb5edcc7125a..267b4aaf0271 100644 > > --- a/fs/internal.h > > +++ b/fs/internal.h > > @@ -102,6 +102,7 @@ extern int fsinfo_generic_mount_topology(struct > > path *, struct fsinfo_context *) > > extern int fsinfo_generic_mount_point(struct path *, struct > > fsinfo_context *); > > extern int fsinfo_generic_mount_point_full(struct path *, struct > > fsinfo_context *); > > extern int fsinfo_generic_mount_children(struct path *, struct > > fsinfo_context *); > > +extern int fsinfo_generic_mount_all(struct path *, struct > > fsinfo_context *); > > > > /* > > * fs_struct.c > > diff --git a/fs/namespace.c b/fs/namespace.c > > index 122c12f9512b..1f2e06507244 100644 > > --- a/fs/namespace.c > > +++ b/fs/namespace.c > > @@ -4494,4 +4494,41 @@ int fsinfo_generic_mount_children(struct > > path *path, struct fsinfo_context *ctx) > > return ctx->usage; > > } > > > > +/* > > + * Return information about all the mounts in the namespace > > referenced by the > > + * path. > > + */ > > +int fsinfo_generic_mount_all(struct path *path, struct > > fsinfo_context *ctx) > > +{ > > + struct mnt_namespace *ns; > > + struct mount *m, *p; > > + struct path chroot; > > + bool allow; > > + > > + m = real_mount(path->mnt); > > + ns = m->mnt_ns; > > + > > + get_fs_root(current->fs, &chroot); > > + rcu_read_lock(); > > + allow = are_paths_connected(&chroot, path) || > > capable(CAP_SYS_ADMIN); > > + rcu_read_unlock(); > > + path_put(&chroot); > > + if (!allow) > > + return -EPERM; > > + > > + down_read(&namespace_sem); > > + > > + list_for_each_entry(p, &ns->list, mnt_list) { > > This is missing locking and check added by commit 9f6c61f96f2d > ("proc/mounts: > add cursor"). That's a good catch Miklos. Yes, the extra lock and the cursor check that's now needed. > > > + struct path mnt_root; > > + > > + mnt_root.mnt = &p->mnt; > > + mnt_root.dentry = p->mnt.mnt_root; > > + if (are_paths_connected(path, &mnt_root)) > > + fsinfo_store_mount(ctx, p, p == m); > > + } > > + > > + up_read(&namespace_sem); > > + return ctx->usage; > > +} > > + > > #endif /* CONFIG_FSINFO */ > > diff --git a/include/uapi/linux/fsinfo.h > > b/include/uapi/linux/fsinfo.h > > index 81329de6905e..e40192d98648 100644 > > --- a/include/uapi/linux/fsinfo.h > > +++ b/include/uapi/linux/fsinfo.h > > @@ -37,6 +37,7 @@ > > #define FSINFO_ATTR_MOUNT_POINT_FULL 0x203 /* Absolute > > path of mount (string) */ > > #define FSINFO_ATTR_MOUNT_TOPOLOGY 0x204 /* Mount object > > topology */ > > #define FSINFO_ATTR_MOUNT_CHILDREN 0x205 /* Children of this > > mount (list) */ > > +#define FSINFO_ATTR_MOUNT_ALL 0x206 /* List all > > mounts in a namespace (list) */ > > > > #define FSINFO_ATTR_AFS_CELL_NAME 0x300 /* AFS cell name > > (string) */ > > #define FSINFO_ATTR_AFS_SERVER_NAME 0x301 /* Name of > > the Nth server (string) */ > > @@ -128,6 +129,8 @@ struct fsinfo_mount_topology { > > /* > > * Information struct element for > > fsinfo(FSINFO_ATTR_MOUNT_CHILDREN). > > * - An extra element is placed on the end representing the parent > > mount. > > + * > > + * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_ALL). > > */ > > struct fsinfo_mount_child { > > __u64 mnt_unique_id; /* Kernel-lifetime unique > > mount ID */ > > @@ -139,6 +142,7 @@ struct fsinfo_mount_child { > > }; > > > > #define FSINFO_ATTR_MOUNT_CHILDREN__STRUCT struct > > fsinfo_mount_child > > +#define FSINFO_ATTR_MOUNT_ALL__STRUCT struct fsinfo_mount_child > > > > /* > > * Information struct for fsinfo(FSINFO_ATTR_STATFS). > > diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c > > index 374825ab85b0..596fa5e71762 100644 > > --- a/samples/vfs/test-fsinfo.c > > +++ b/samples/vfs/test-fsinfo.c > > @@ -365,6 +365,27 @@ static void > > dump_fsinfo_generic_mount_children(void *reply, unsigned int size) > > (unsigned long long)r->mnt_notify_sum, mp); > > } > > > > +static void dump_fsinfo_generic_mount_all(void *reply, unsigned > > int size) > > +{ > > + struct fsinfo_mount_child *r = reply; > > + ssize_t mplen; > > + char path[32], *mp; > > + > > + struct fsinfo_params params = { > > + .flags = FSINFO_FLAGS_QUERY_MOUNT, > > + .request = FSINFO_ATTR_MOUNT_POINT_FULL, > > + }; > > + > > + sprintf(path, "%u", r->mnt_id); > > + mplen = get_fsinfo(path, "FSINFO_ATTR_MOUNT_POINT_FULL", > > ¶ms, (void **)&mp); > > + if (mplen < 0) > > + mp = "-"; > > + > > + printf("%5x %5x %12llx %10llu %s\n", > > + r->mnt_id, r->parent_id, (unsigned long long)r- > > >mnt_unique_id, > > + r->mnt_notify_sum, mp); > > +} > > + > > static void dump_afs_fsinfo_server_address(void *reply, unsigned > > int size) > > { > > struct fsinfo_afs_server_address *f = reply; > > @@ -492,6 +513,7 @@ static const struct fsinfo_attribute > > fsinfo_attributes[] = { > > FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT, string), > > FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT_FULL, string), > > FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_moun > > t_children), > > + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_moun > > t_all), > > > > FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, string), > > FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, string), > > > >
Miklos Szeredi <miklos@szeredi.hu> wrote: > > where each element contains a once-in-a-system-lifetime unique ID, the > > mount ID (which may get reused), the parent mount ID and sums of the > > notification/change counters for the mount and its superblock. > > The change counters are currently conditional on CONFIG_MOUNT_NOTIFICATIONS. > Is this is intentional? Yeah - the counters aren't driven unless CONFIG_MOUNT_NOTIFICATIONS=y. I could perhaps make it so they're driven in both cases, but driving the in-subtree counter is somewhat tied up in the notification posting. This is something that can be fixed after this patchset is taken - if it is taken since that doesn't change the UAPI. David
diff --git a/fs/fsinfo.c b/fs/fsinfo.c index 0540cce89555..f230124ffdf5 100644 --- a/fs/fsinfo.c +++ b/fs/fsinfo.c @@ -296,6 +296,7 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = { FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT, fsinfo_generic_mount_point), FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT_FULL, fsinfo_generic_mount_point_full), FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_children), + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_mount_all), {} }; diff --git a/fs/internal.h b/fs/internal.h index cb5edcc7125a..267b4aaf0271 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -102,6 +102,7 @@ extern int fsinfo_generic_mount_topology(struct path *, struct fsinfo_context *) extern int fsinfo_generic_mount_point(struct path *, struct fsinfo_context *); extern int fsinfo_generic_mount_point_full(struct path *, struct fsinfo_context *); extern int fsinfo_generic_mount_children(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_mount_all(struct path *, struct fsinfo_context *); /* * fs_struct.c diff --git a/fs/namespace.c b/fs/namespace.c index 122c12f9512b..1f2e06507244 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -4494,4 +4494,41 @@ int fsinfo_generic_mount_children(struct path *path, struct fsinfo_context *ctx) return ctx->usage; } +/* + * Return information about all the mounts in the namespace referenced by the + * path. + */ +int fsinfo_generic_mount_all(struct path *path, struct fsinfo_context *ctx) +{ + struct mnt_namespace *ns; + struct mount *m, *p; + struct path chroot; + bool allow; + + m = real_mount(path->mnt); + ns = m->mnt_ns; + + get_fs_root(current->fs, &chroot); + rcu_read_lock(); + allow = are_paths_connected(&chroot, path) || capable(CAP_SYS_ADMIN); + rcu_read_unlock(); + path_put(&chroot); + if (!allow) + return -EPERM; + + down_read(&namespace_sem); + + list_for_each_entry(p, &ns->list, mnt_list) { + struct path mnt_root; + + mnt_root.mnt = &p->mnt; + mnt_root.dentry = p->mnt.mnt_root; + if (are_paths_connected(path, &mnt_root)) + fsinfo_store_mount(ctx, p, p == m); + } + + up_read(&namespace_sem); + return ctx->usage; +} + #endif /* CONFIG_FSINFO */ diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 81329de6905e..e40192d98648 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -37,6 +37,7 @@ #define FSINFO_ATTR_MOUNT_POINT_FULL 0x203 /* Absolute path of mount (string) */ #define FSINFO_ATTR_MOUNT_TOPOLOGY 0x204 /* Mount object topology */ #define FSINFO_ATTR_MOUNT_CHILDREN 0x205 /* Children of this mount (list) */ +#define FSINFO_ATTR_MOUNT_ALL 0x206 /* List all mounts in a namespace (list) */ #define FSINFO_ATTR_AFS_CELL_NAME 0x300 /* AFS cell name (string) */ #define FSINFO_ATTR_AFS_SERVER_NAME 0x301 /* Name of the Nth server (string) */ @@ -128,6 +129,8 @@ struct fsinfo_mount_topology { /* * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_CHILDREN). * - An extra element is placed on the end representing the parent mount. + * + * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_ALL). */ struct fsinfo_mount_child { __u64 mnt_unique_id; /* Kernel-lifetime unique mount ID */ @@ -139,6 +142,7 @@ struct fsinfo_mount_child { }; #define FSINFO_ATTR_MOUNT_CHILDREN__STRUCT struct fsinfo_mount_child +#define FSINFO_ATTR_MOUNT_ALL__STRUCT struct fsinfo_mount_child /* * Information struct for fsinfo(FSINFO_ATTR_STATFS). diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 374825ab85b0..596fa5e71762 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -365,6 +365,27 @@ static void dump_fsinfo_generic_mount_children(void *reply, unsigned int size) (unsigned long long)r->mnt_notify_sum, mp); } +static void dump_fsinfo_generic_mount_all(void *reply, unsigned int size) +{ + struct fsinfo_mount_child *r = reply; + ssize_t mplen; + char path[32], *mp; + + struct fsinfo_params params = { + .flags = FSINFO_FLAGS_QUERY_MOUNT, + .request = FSINFO_ATTR_MOUNT_POINT_FULL, + }; + + sprintf(path, "%u", r->mnt_id); + mplen = get_fsinfo(path, "FSINFO_ATTR_MOUNT_POINT_FULL", ¶ms, (void **)&mp); + if (mplen < 0) + mp = "-"; + + printf("%5x %5x %12llx %10llu %s\n", + r->mnt_id, r->parent_id, (unsigned long long)r->mnt_unique_id, + r->mnt_notify_sum, mp); +} + static void dump_afs_fsinfo_server_address(void *reply, unsigned int size) { struct fsinfo_afs_server_address *f = reply; @@ -492,6 +513,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT, string), FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT_FULL, string), FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_children), + FSINFO_LIST (FSINFO_ATTR_MOUNT_ALL, fsinfo_generic_mount_all), FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, string), FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, string),
Add a filesystem attribute that exports a list of all the visible mounts in a namespace, given the caller's chroot setting. The returned list is an array of: struct fsinfo_mount_child { __u64 mnt_unique_id; __u32 mnt_id; __u32 parent_id; __u32 mnt_notify_sum; __u32 sb_notify_sum; }; where each element contains a once-in-a-system-lifetime unique ID, the mount ID (which may get reused), the parent mount ID and sums of the notification/change counters for the mount and its superblock. This works with a read lock on the namespace_sem, but ideally would do it under the RCU read lock only. Signed-off-by: David Howells <dhowells@redhat.com> --- fs/fsinfo.c | 1 + fs/internal.h | 1 + fs/namespace.c | 37 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/fsinfo.h | 4 ++++ samples/vfs/test-fsinfo.c | 22 ++++++++++++++++++++++ 5 files changed, 65 insertions(+)