Merge tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual fses.

  Features:

   - Add Jan Kara as VFS reviewer

   - Show correct device and inode numbers in proc/<pid>/maps for vma
     files on stacked filesystems. This is now easily doable thanks to
     the backing file work from the last cycles. This comes with
     selftests

  Cleanups:

   - Remove a redundant might_sleep() from wait_on_inode()

   - Initialize pointer with NULL, not 0

   - Clarify comment on access_override_creds()

   - Rework and simplify eventfd_signal() and eventfd_signal_mask()
     helpers

   - Process aio completions in batches to avoid needless wakeups

   - Completely decouple struct mnt_idmap from namespaces. We now only
     keep the actual idmapping around and don't stash references to
     namespaces

   - Reformat maintainer entries to indicate that a given subsystem
     belongs to fs/

   - Simplify fput() for files that were never opened

   - Get rid of various pointless file helpers

   - Rename various file helpers

   - Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from
     last cycle

   - Make relatime_need_update() return bool

   - Use GFP_KERNEL instead of GFP_USER when allocating superblocks

   - Replace deprecated ida_simple_*() calls with their current ida_*()
     counterparts

  Fixes:

   - Fix comments on user namespace id mapping helpers. They aren't
     kernel doc comments so they shouldn't be using /**

   - s/Retuns/Returns/g in various places

   - Add missing parameter documentation on can_move_mount_beneath()

   - Rename i_mapping->private_data to i_mapping->i_private_data

   - Fix a false-positive lockdep warning in pipe_write() for watch
     queues

   - Improve __fget_files_rcu() code generation to improve performance

   - Only notify writer that pipe resizing has finished after setting
     pipe->max_usage otherwise writers are never notified that the pipe
     has been resized and hang

   - Fix some kernel docs in hfsplus

   - s/passs/pass/g in various places

   - Fix kernel docs in ntfs

   - Fix kcalloc() arguments order reported by gcc 14

   - Fix uninitialized value in reiserfs"

* tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits)
  reiserfs: fix uninit-value in comp_keys
  watch_queue: fix kcalloc() arguments order
  ntfs: dir.c: fix kernel-doc function parameter warnings
  fs: fix doc comment typo fs tree wide
  selftests/overlayfs: verify device and inode numbers in /proc/pid/maps
  fs/proc: show correct device and inode numbers in /proc/pid/maps
  eventfd: Remove usage of the deprecated ida_simple_xx() API
  fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation
  fs/hfsplus: wrapper.c: fix kernel-doc warnings
  fs: add Jan Kara as reviewer
  fs/inode: Make relatime_need_update return bool
  pipe: wakeup wr_wait after setting max_usage
  file: remove __receive_fd()
  file: stop exposing receive_fd_user()
  fs: replace f_rcuhead with f_task_work
  file: remove pointless wrapper
  file: s/close_fd_get_file()/file_close_fd()/g
  Improve __fget_files_rcu() code generation (and thus __fget_light())
  file: massage cleanup of files that failed to open
  fs/pipe: Fix lockdep false-positive in watchqueue pipe_write()
  ...

8 files changed, 64 insertions, 44 deletions

diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index b9d83652c097..e32bee4345fb 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -35,8 +35,7 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx);
 struct file *eventfd_fget(int fd);
 struct eventfd_ctx *eventfd_ctx_fdget(int fd);
 struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
-__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask);
+void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
 int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
 				  __u64 *cnt);
 void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
@@ -58,15 +57,8 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
 	return ERR_PTR(-ENOSYS);
 }
 
-static inline int eventfd_signal(struct eventfd_ctx *ctx, __u64 n)
+static inline void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
 {
-	return -ENOSYS;
-}
-
-static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n,
-				      unsigned mask)
-{
-	return -ENOSYS;
 }
 
 static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
@@ -92,5 +84,10 @@ static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)
 
 #endif
 
+static inline void eventfd_signal(struct eventfd_ctx *ctx)
+{
+	eventfd_signal_mask(ctx, 0);
+}
+
 #endif /* _LINUX_EVENTFD_H */
 
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index bc4c3287a65e..78c8326d74ae 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -83,12 +83,17 @@ struct dentry;
 static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsigned int fd)
 {
 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);
-
-	if (fd < fdt->max_fds) {
-		fd = array_index_nospec(fd, fdt->max_fds);
-		return rcu_dereference_raw(fdt->fd[fd]);
-	}
-	return NULL;
+	unsigned long mask = array_index_mask_nospec(fd, fdt->max_fds);
+	struct file *needs_masking;
+
+	/*
+	 * 'mask' is zero for an out-of-bounds fd, all ones for ok.
+	 * 'fd&mask' is 'fd' for ok, or 0 for out of bounds.
+	 *
+	 * Accessing fdt->fd[0] is ok, but needs masking of the result.
+	 */
+	needs_masking = rcu_dereference_raw(fdt->fd[fd&mask]);
+	return (struct file *)(mask & (unsigned long)needs_masking);
 }
 
 static inline struct file *files_lookup_fd_locked(struct files_struct *files, unsigned int fd)
@@ -114,7 +119,7 @@ int iterate_fd(struct files_struct *, unsigned,
 
 extern int close_fd(unsigned int fd);
 extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags);
-extern struct file *close_fd_get_file(unsigned int fd);
+extern struct file *file_close_fd(unsigned int fd);
 extern int unshare_fd(unsigned long unshare_flags, unsigned int max_fds,
 		      struct files_struct **new_fdp);
 
diff --git a/include/linux/file.h b/include/linux/file.h
index 6e9099d29343..6834a29338c4 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -96,18 +96,8 @@ DEFINE_CLASS(get_unused_fd, int, if (_T >= 0) put_unused_fd(_T),
 
 extern void fd_install(unsigned int fd, struct file *file);
 
-extern int __receive_fd(struct file *file, int __user *ufd,
-			unsigned int o_flags);
+int receive_fd(struct file *file, int __user *ufd, unsigned int o_flags);
 
-extern int receive_fd(struct file *file, unsigned int o_flags);
-
-static inline int receive_fd_user(struct file *file, int __user *ufd,
-				  unsigned int o_flags)
-{
-	if (ufd == NULL)
-		return -EFAULT;
-	return __receive_fd(file, ufd, o_flags);
-}
 int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags);
 
 extern void flush_delayed_fput(void);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 98b7a7a8c42e..3d58376ed39e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -463,9 +463,9 @@ extern const struct address_space_operations empty_aops;
  * @a_ops: Methods.
  * @flags: Error bits and flags (AS_*).
  * @wb_err: The most recent error which has occurred.
- * @private_lock: For use by the owner of the address_space.
- * @private_list: For use by the owner of the address_space.
- * @private_data: For use by the owner of the address_space.
+ * @i_private_lock: For use by the owner of the address_space.
+ * @i_private_list: For use by the owner of the address_space.
+ * @i_private_data: For use by the owner of the address_space.
  */
 struct address_space {
 	struct inode		*host;
@@ -484,9 +484,9 @@ struct address_space {
 	unsigned long		flags;
 	struct rw_semaphore	i_mmap_rwsem;
 	errseq_t		wb_err;
-	spinlock_t		private_lock;
-	struct list_head	private_list;
-	void			*private_data;
+	spinlock_t		i_private_lock;
+	struct list_head	i_private_list;
+	void *			i_private_data;
 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
 	/*
 	 * On most architectures that alignment is already the case; but
@@ -991,8 +991,10 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
  */
 struct file {
 	union {
+		/* fput() uses task work when closing and freeing file (default). */
+		struct callback_head 	f_task_work;
+		/* fput() must use workqueue (most kernel threads). */
 		struct llist_node	f_llist;
-		struct rcu_head 	f_rcuhead;
 		unsigned int 		f_iocb_flags;
 	};
 
@@ -2523,20 +2525,28 @@ struct file *backing_file_open(const struct path *user_path, int flags,
 struct path *backing_file_user_path(struct file *f);
 
 /*
- * file_user_path - get the path to display for memory mapped file
- *
  * When mmapping a file on a stackable filesystem (e.g., overlayfs), the file
  * stored in ->vm_file is a backing file whose f_inode is on the underlying
- * filesystem.  When the mapped file path is displayed to user (e.g. via
- * /proc/<pid>/maps), this helper should be used to get the path to display
- * to the user, which is the path of the fd that user has requested to map.
+ * filesystem.  When the mapped file path and inode number are displayed to
+ * user (e.g. via /proc/<pid>/maps), these helpers should be used to get the
+ * path and inode number to display to the user, which is the path of the fd
+ * that user has requested to map and the inode number that would be returned
+ * by fstat() on that same fd.
  */
+/* Get the path to display in /proc/<pid>/maps */
 static inline const struct path *file_user_path(struct file *f)
 {
 	if (unlikely(f->f_mode & FMODE_BACKING))
 		return backing_file_user_path(f);
 	return &f->f_path;
 }
+/* Get the inode whose inode number to display in /proc/<pid>/maps */
+static inline const struct inode *file_user_inode(struct file *f)
+{
+	if (unlikely(f->f_mode & FMODE_BACKING))
+		return d_inode(backing_file_user_path(f)->dentry);
+	return file_inode(f);
+}
 
 static inline struct file *file_clone_open(struct file *file)
 {
diff --git a/include/linux/mnt_idmapping.h b/include/linux/mnt_idmapping.h
index b8da2db4ecd2..cd4d5c8781f5 100644
--- a/include/linux/mnt_idmapping.h
+++ b/include/linux/mnt_idmapping.h
@@ -244,7 +244,4 @@ static inline kgid_t mapped_fsgid(struct mnt_idmap *idmap,
 	return from_vfsgid(idmap, fs_userns, VFSGIDT_INIT(current_fsgid()));
 }
 
-bool check_fsmapping(const struct mnt_idmap *idmap,
-		     const struct super_block *sb);
-
 #endif /* _LINUX_MNT_IDMAPPING_H */
diff --git a/include/linux/uidgid.h b/include/linux/uidgid.h
index b0542cd11aeb..415a7ca2b882 100644
--- a/include/linux/uidgid.h
+++ b/include/linux/uidgid.h
@@ -17,6 +17,7 @@
 
 struct user_namespace;
 extern struct user_namespace init_user_ns;
+struct uid_gid_map;
 
 typedef struct {
 	uid_t val;
@@ -138,6 +139,9 @@ static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
 	return from_kgid(ns, gid) != (gid_t) -1;
 }
 
+u32 map_id_down(struct uid_gid_map *map, u32 id);
+u32 map_id_up(struct uid_gid_map *map, u32 id);
+
 #else
 
 static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
@@ -186,6 +190,15 @@ static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
 	return gid_valid(gid);
 }
 
+static inline u32 map_id_down(struct uid_gid_map *map, u32 id)
+{
+	return id;
+}
+
+static inline u32 map_id_up(struct uid_gid_map *map, u32 id)
+{
+	return id;
+}
 #endif /* CONFIG_USER_NS */
 
 #endif /* _LINUX_UIDGID_H */
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 083387c00f0c..6d0a14f7019d 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -193,7 +193,6 @@ void inode_io_list_del(struct inode *inode);
 /* writeback.h requires fs.h; it, too, is not included from here. */
 static inline void wait_on_inode(struct inode *inode)
 {
-	might_sleep();
 	wait_on_bit(&inode->i_state, __I_NEW, TASK_UNINTERRUPTIBLE);
 }
 
diff --git a/include/net/scm.h b/include/net/scm.h
index e8c76b4be2fe..cf68acec4d70 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -5,6 +5,7 @@
 #include <linux/limits.h>
 #include <linux/net.h>
 #include <linux/cred.h>
+#include <linux/file.h>
 #include <linux/security.h>
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
@@ -208,5 +209,13 @@ static inline void scm_recv_unix(struct socket *sock, struct msghdr *msg,
 	scm_destroy_cred(scm);
 }
 
+static inline int scm_recv_one_fd(struct file *f, int __user *ufd,
+				  unsigned int flags)
+{
+	if (!ufd)
+		return -EFAULT;
+	return receive_fd(f, ufd, flags);
+}
+
 #endif /* __LINUX_NET_SCM_H */