diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index dd33227e518aaf4d6c3a3bd60d71ced8eb28455d..5558316036370242320fd22cb2840852b31ddf90 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -153,26 +153,20 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info,
}
static int fanotify_encode_fid(struct fanotify_event *event,
- const struct path *path, gfp_t gfp)
+ struct inode *inode, gfp_t gfp,
+ __kernel_fsid_t *fsid)
{
struct fanotify_fid *fid = &event->fid;
int dwords, bytes = 0;
- struct kstatfs stat;
int err, type;
- stat.f_fsid.val[0] = stat.f_fsid.val[1] = 0;
fid->ext_fh = NULL;
dwords = 0;
err = -ENOENT;
- type = exportfs_encode_inode_fh(d_inode(path->dentry), NULL, &dwords,
- NULL);
+ type = exportfs_encode_inode_fh(inode, NULL, &dwords, NULL);
if (!dwords)
goto out_err;
- err = vfs_statfs(path, &stat);
- if (err)
- goto out_err;
-
bytes = dwords << 2;
if (bytes > FANOTIFY_INLINE_FH_LEN) {
/* Treat failure to allocate fh as failure to allocate event */
@@ -182,14 +176,13 @@ static int fanotify_encode_fid(struct fanotify_event *event,
goto out_err;
}
- type = exportfs_encode_inode_fh(d_inode(path->dentry),
- fanotify_fid_fh(fid, bytes), &dwords,
- NULL);
+ type = exportfs_encode_inode_fh(inode, fanotify_fid_fh(fid, bytes),
+ &dwords, NULL);
err = -EINVAL;
if (!type || type == FILEID_INVALID || bytes != dwords << 2)
goto out_err;
- fid->fsid = stat.f_fsid;
+ fid->fsid = *fsid;
event->fh_len = bytes;
return type;
@@ -197,8 +190,7 @@ static int fanotify_encode_fid(struct fanotify_event *event,
out_err:
pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
"type=%d, bytes=%d, err=%i)\n",
- stat.f_fsid.val[0], stat.f_fsid.val[1],
- type, bytes, err);
+ fsid->val[0], fsid->val[1], type, bytes, err);
kfree(fid->ext_fh);
fid->ext_fh = NULL;
event->fh_len = 0;
@@ -207,8 +199,9 @@ static int fanotify_encode_fid(struct fanotify_event *event,
}
struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
- struct inode *inode, u32 mask,
- const struct path *path)
+ struct inode *inode, u32 mask,
+ const struct path *path,
+ __kernel_fsid_t *fsid)
{
struct fanotify_event *event = NULL;
gfp_t gfp = GFP_KERNEL_ACCOUNT;
@@ -247,7 +240,8 @@ init: __maybe_unused
event->fh_len = 0;
if (path && FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
/* Report the event without a file identifier on encode error */
- event->fh_type = fanotify_encode_fid(event, path, gfp);
+ event->fh_type = fanotify_encode_fid(event,
+ d_inode(path->dentry), gfp, fsid);
} else if (path) {
event->fh_type = FILEID_ROOT;
event->path = *path;
@@ -262,6 +256,29 @@ init: __maybe_unused
return event;
}
+/*
+ * Get cached fsid of the filesystem containing the object from any connector.
+ * All connectors are supposed to have the same fsid, but we do not verify that
+ * here.
+ */
+static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info)
+{
+ int type;
+ __kernel_fsid_t fsid = {};
+
+ fsnotify_foreach_obj_type(type) {
+ if (!fsnotify_iter_should_report_type(iter_info, type))
+ continue;
+
+ fsid = iter_info->marks[type]->connector->fsid;
+ if (WARN_ON_ONCE(!fsid.val[0] && !fsid.val[1]))
+ continue;
+ return fsid;
+ }
+
+ return fsid;
+}
+
static int fanotify_handle_event(struct fsnotify_group *group,
struct inode *inode,
u32 mask, const void *data, int data_type,
@@ -271,6 +288,7 @@ static int fanotify_handle_event(struct fsnotify_group *group,
int ret = 0;
struct fanotify_event *event;
struct fsnotify_event *fsn_event;
+ __kernel_fsid_t fsid = {};
BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
@@ -303,7 +321,10 @@ static int fanotify_handle_event(struct fsnotify_group *group,
return 0;
}
- event = fanotify_alloc_event(group, inode, mask, data);
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_FID))
+ fsid = fanotify_get_fsid(iter_info);
+
+ event = fanotify_alloc_event(group, inode, mask, data, &fsid);
ret = -ENOMEM;
if (unlikely(!event)) {
/*
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 4aafc7144c3d6eae52fbe0e9e6ba70a47888fc44..5b072afa4e191e43aebf009dc43a4e6b5a3ff341 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -131,5 +131,6 @@ static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse)
}
struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
- struct inode *inode, u32 mask,
- const struct path *path);
+ struct inode *inode, u32 mask,
+ const struct path *path,
+ __kernel_fsid_t *fsid);
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 1638c171ca824c1035c84c82e000cbd16b96fed3..603419ce096f083d86e8199619729d6c428ccd34 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -653,7 +653,8 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp,
- unsigned int type)
+ unsigned int type,
+ __kernel_fsid_t *fsid)
{
struct fsnotify_mark *mark;
int ret;
@@ -666,7 +667,7 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
return ERR_PTR(-ENOMEM);
fsnotify_init_mark(mark, group);
- ret = fsnotify_add_mark_locked(mark, connp, type, 0);
+ ret = fsnotify_add_mark_locked(mark, connp, type, 0, fsid);
if (ret) {
fsnotify_put_mark(mark);
return ERR_PTR(ret);
@@ -678,7 +679,8 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group,
static int fanotify_add_mark(struct fsnotify_group *group,
fsnotify_connp_t *connp, unsigned int type,
- __u32 mask, unsigned int flags)
+ __u32 mask, unsigned int flags,
+ __kernel_fsid_t *fsid)
{
struct fsnotify_mark *fsn_mark;
__u32 added;
@@ -686,7 +688,7 @@ static int fanotify_add_mark(struct fsnotify_group *group,
mutex_lock(&group->mark_mutex);
fsn_mark = fsnotify_find_mark(connp, group);
if (!fsn_mark) {
- fsn_mark = fanotify_add_new_mark(group, connp, type);
+ fsn_mark = fanotify_add_new_mark(group, connp, type, fsid);
if (IS_ERR(fsn_mark)) {
mutex_unlock(&group->mark_mutex);
return PTR_ERR(fsn_mark);
@@ -703,23 +705,23 @@ static int fanotify_add_mark(struct fsnotify_group *group,
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
struct vfsmount *mnt, __u32 mask,
- unsigned int flags)
+ unsigned int flags, __kernel_fsid_t *fsid)
{
return fanotify_add_mark(group, &real_mount(mnt)->mnt_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags);
+ FSNOTIFY_OBJ_TYPE_VFSMOUNT, mask, flags, fsid);
}
static int fanotify_add_sb_mark(struct fsnotify_group *group,
- struct super_block *sb, __u32 mask,
- unsigned int flags)
+ struct super_block *sb, __u32 mask,
+ unsigned int flags, __kernel_fsid_t *fsid)
{
return fanotify_add_mark(group, &sb->s_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_SB, mask, flags);
+ FSNOTIFY_OBJ_TYPE_SB, mask, flags, fsid);
}
static int fanotify_add_inode_mark(struct fsnotify_group *group,
struct inode *inode, __u32 mask,
- unsigned int flags)
+ unsigned int flags, __kernel_fsid_t *fsid)
{
pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
@@ -734,7 +736,7 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
return 0;
return fanotify_add_mark(group, &inode->i_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_INODE, mask, flags);
+ FSNOTIFY_OBJ_TYPE_INODE, mask, flags, fsid);
}
/* fanotify syscalls */
@@ -798,7 +800,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
atomic_inc(&user->fanotify_listeners);
group->memcg = get_mem_cgroup_from_mm(current->mm);
- oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL);
+ oevent = fanotify_alloc_event(group, NULL, FS_Q_OVERFLOW, NULL, NULL);
if (unlikely(!oevent)) {
fd = -ENOMEM;
goto out_destroy_group;
@@ -861,9 +863,9 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
}
/* Check if filesystem can encode a unique fid */
-static int fanotify_test_fid(struct path *path)
+static int fanotify_test_fid(struct path *path, struct kstatfs *stat)
{
- struct kstatfs stat, root_stat;
+ struct kstatfs root_stat;
struct path root = {
.mnt = path->mnt,
.dentry = path->dentry->d_sb->s_root,
@@ -873,11 +875,11 @@ static int fanotify_test_fid(struct path *path)
/*
* Make sure path is not in filesystem with zero fsid (e.g. tmpfs).
*/
- err = vfs_statfs(path, &stat);
+ err = vfs_statfs(path, stat);
if (err)
return err;
- if (!stat.f_fsid.val[0] && !stat.f_fsid.val[1])
+ if (!stat->f_fsid.val[0] && !stat->f_fsid.val[1])
return -ENODEV;
/*
@@ -888,8 +890,8 @@ static int fanotify_test_fid(struct path *path)
if (err)
return err;
- if (root_stat.f_fsid.val[0] != stat.f_fsid.val[0] ||
- root_stat.f_fsid.val[1] != stat.f_fsid.val[1])
+ if (root_stat.f_fsid.val[0] != stat->f_fsid.val[0] ||
+ root_stat.f_fsid.val[1] != stat->f_fsid.val[1])
return -EXDEV;
/*
@@ -914,6 +916,8 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
struct fsnotify_group *group;
struct fd f;
struct path path;
+ struct kstatfs stat;
+ __kernel_fsid_t *fsid = NULL;
u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS;
unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
int ret;
@@ -992,9 +996,11 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
goto fput_and_out;
if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
- ret = fanotify_test_fid(&path);
+ ret = fanotify_test_fid(&path, &stat);
if (ret)
goto path_put_and_out;
+
+ fsid = &stat.f_fsid;
}
/* inode held in place by reference to path; group by fget on fd */
@@ -1007,19 +1013,25 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) {
case FAN_MARK_ADD:
if (mark_type == FAN_MARK_MOUNT)
- ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
+ ret = fanotify_add_vfsmount_mark(group, mnt, mask,
+ flags, fsid);
else if (mark_type == FAN_MARK_FILESYSTEM)
- ret = fanotify_add_sb_mark(group, mnt->mnt_sb, mask, flags);
+ ret = fanotify_add_sb_mark(group, mnt->mnt_sb, mask,
+ flags, fsid);
else
- ret = fanotify_add_inode_mark(group, inode, mask, flags);
+ ret = fanotify_add_inode_mark(group, inode, mask,
+ flags, fsid);
break;
case FAN_MARK_REMOVE:
if (mark_type == FAN_MARK_MOUNT)
- ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
+ ret = fanotify_remove_vfsmount_mark(group, mnt, mask,
+ flags);
else if (mark_type == FAN_MARK_FILESYSTEM)
- ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask, flags);
+ ret = fanotify_remove_sb_mark(group, mnt->mnt_sb, mask,
+ flags);
else
- ret = fanotify_remove_inode_mark(group, inode, mask, flags);
+ ret = fanotify_remove_inode_mark(group, inode, mask,
+ flags);
break;
default:
ret = -EINVAL;
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index d2dd16cb5989144d4289cc879a4a34d2af81c216..d593d42695618f20f585e97ddb835305f7d72e00 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -82,6 +82,7 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/srcu.h>
+#include <linux/ratelimit.h>
#include <linux/atomic.h>
@@ -481,7 +482,8 @@ int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b)
}
static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
- unsigned int type)
+ unsigned int type,
+ __kernel_fsid_t *fsid)
{
struct inode *inode = NULL;
struct fsnotify_mark_connector *conn;
@@ -493,6 +495,11 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp,
INIT_HLIST_HEAD(&conn->list);
conn->type = type;
conn->obj = connp;
+ /* Cache fsid of filesystem containing the object */
+ if (fsid)
+ conn->fsid = *fsid;
+ else
+ conn->fsid.val[0] = conn->fsid.val[1] = 0;
if (conn->type == FSNOTIFY_OBJ_TYPE_INODE)
inode = igrab(fsnotify_conn_inode(conn));
/*
@@ -544,7 +551,7 @@ static struct fsnotify_mark_connector *fsnotify_grab_connector(
*/
static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
fsnotify_connp_t *connp, unsigned int type,
- int allow_dups)
+ int allow_dups, __kernel_fsid_t *fsid)
{
struct fsnotify_mark *lmark, *last = NULL;
struct fsnotify_mark_connector *conn;
@@ -553,15 +560,36 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
if (WARN_ON(!fsnotify_valid_obj_type(type)))
return -EINVAL;
+
+ /* Backend is expected to check for zero fsid (e.g. tmpfs) */
+ if (fsid && WARN_ON_ONCE(!fsid->val[0] && !fsid->val[1]))
+ return -ENODEV;
+
restart:
spin_lock(&mark->lock);
conn = fsnotify_grab_connector(connp);
if (!conn) {
spin_unlock(&mark->lock);
- err = fsnotify_attach_connector_to_object(connp, type);
+ err = fsnotify_attach_connector_to_object(connp, type, fsid);
if (err)
return err;
goto restart;
+ } else if (fsid && (conn->fsid.val[0] || conn->fsid.val[1]) &&
+ (fsid->val[0] != conn->fsid.val[0] ||
+ fsid->val[1] != conn->fsid.val[1])) {
+ /*
+ * Backend is expected to check for non uniform fsid
+ * (e.g. btrfs), but maybe we missed something?
+ * Only allow setting conn->fsid once to non zero fsid.
+ * inotify and non-fid fanotify groups do not set nor test
+ * conn->fsid.
+ */
+ pr_warn_ratelimited("%s: fsid mismatch on object of type %u: "
+ "%x.%x != %x.%x\n", __func__, conn->type,
+ fsid->val[0], fsid->val[1],
+ conn->fsid.val[0], conn->fsid.val[1]);
+ err = -EXDEV;
+ goto out_err;
}
/* is mark the first mark? */
@@ -606,7 +634,7 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark,
*/
int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
fsnotify_connp_t *connp, unsigned int type,
- int allow_dups)
+ int allow_dups, __kernel_fsid_t *fsid)
{
struct fsnotify_group *group = mark->group;
int ret = 0;
@@ -627,7 +655,7 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
fsnotify_get_mark(mark); /* for g_list */
spin_unlock(&mark->lock);
- ret = fsnotify_add_mark_list(mark, connp, type, allow_dups);
+ ret = fsnotify_add_mark_list(mark, connp, type, allow_dups, fsid);
if (ret)
goto err;
@@ -648,13 +676,13 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
}
int fsnotify_add_mark(struct fsnotify_mark *mark, fsnotify_connp_t *connp,
- unsigned int type, int allow_dups)
+ unsigned int type, int allow_dups, __kernel_fsid_t *fsid)
{
int ret;
struct fsnotify_group *group = mark->group;
mutex_lock(&group->mark_mutex);
- ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups);
+ ret = fsnotify_add_mark_locked(mark, connp, type, allow_dups, fsid);
mutex_unlock(&group->mark_mutex);
return ret;
}
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 1e4b88bd1443c2dff9400b5abb678b3a8e6d6c8f..7b93f15b4944a4befb67c5f18f808a0cd00aea48 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -293,6 +293,7 @@ typedef struct fsnotify_mark_connector __rcu *fsnotify_connp_t;
struct fsnotify_mark_connector {
spinlock_t lock;
unsigned int type; /* Type of object [lock] */
+ __kernel_fsid_t fsid; /* fsid of filesystem containing object */
union {
/* Object pointer [lock] */
fsnotify_connp_t *obj;
@@ -433,28 +434,35 @@ extern void fsnotify_init_mark(struct fsnotify_mark *mark,
/* Find mark belonging to given group in the list of marks */
extern struct fsnotify_mark *fsnotify_find_mark(fsnotify_connp_t *connp,
struct fsnotify_group *group);
+/* Get cached fsid of filesystem containing object */
+extern int fsnotify_get_conn_fsid(const struct fsnotify_mark_connector *conn,
+ __kernel_fsid_t *fsid);
/* attach the mark to the object */
extern int fsnotify_add_mark(struct fsnotify_mark *mark,
fsnotify_connp_t *connp, unsigned int type,
- int allow_dups);
+ int allow_dups, __kernel_fsid_t *fsid);
extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
- fsnotify_connp_t *connp, unsigned int type,
- int allow_dups);
+ fsnotify_connp_t *connp,
+ unsigned int type, int allow_dups,
+ __kernel_fsid_t *fsid);
+
/* attach the mark to the inode */
static inline int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
struct inode *inode,
int allow_dups)
{
return fsnotify_add_mark(mark, &inode->i_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_INODE, allow_dups);
+ FSNOTIFY_OBJ_TYPE_INODE, allow_dups, NULL);
}
static inline int fsnotify_add_inode_mark_locked(struct fsnotify_mark *mark,
struct inode *inode,
int allow_dups)
{
return fsnotify_add_mark_locked(mark, &inode->i_fsnotify_marks,
- FSNOTIFY_OBJ_TYPE_INODE, allow_dups);
+ FSNOTIFY_OBJ_TYPE_INODE, allow_dups,
+ NULL);
}
+
/* given a group and a mark, flag mark to be freed when all references are dropped */
extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,
struct fsnotify_group *group);