Merge tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Support passing NULL along AT_EMPTY_PATH for statx().

     NULL paths with any flag value other than AT_EMPTY_PATH go the
     usual route and end up with -EFAULT to retain compatibility (Rust
     is abusing calls of the sort to detect availability of statx)

     This avoids path lookup code, lockref management, memory allocation
     and in case of NULL path userspace memory access (which can be
     quite expensive with SMAP on x86_64)

   - Don't block i_writecount during exec. Remove the
     deny_write_access() mechanism for executables

   - Relax open_by_handle_at() permissions in specific cases where we
     can prove that the caller had sufficient privileges to open a file

   - Switch timespec64 fields in struct inode to discrete integers
     freeing up 4 bytes

  Fixes:

   - Fix false positive circular locking warning in hfsplus

   - Initialize hfs_inode_info after hfs_alloc_inode() in hfs

   - Avoid accidental overflows in vfs_fallocate()

   - Don't interrupt fallocate with EINTR in tmpfs to avoid constantly
     restarting shmem_fallocate()

   - Add missing quote in comment in fs/readdir

  Cleanups:

   - Don't assign and test in an if statement in mqueue. Move the
     assignment out of the if statement

   - Reflow the logic in may_create_in_sticky()

   - Remove the usage of the deprecated ida_simple_xx() API from procfs

   - Reject FSCONFIG_CMD_CREATE_EXCL requets that depend on the new
     mount api early

   - Rename variables in copy_tree() to make it easier to understand

   - Replace WARN(down_read_trylock, ...) abuse with proper asserts in
     various places in the VFS

   - Get rid of user_path_at_empty() and drop the empty argument from
     getname_flags()

   - Check for error while copying and no path in one branch in
     getname_flags()

   - Avoid redundant smp_mb() for THP handling in do_dentry_open()

   - Rename parent_ino to d_parent_ino and make it use RCU

   - Remove unused header include in fs/readdir

   - Export in_group_capable() helper and switch f2fs and fuse over to
     it instead of open-coding the logic in both places"

* tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  ipc: mqueue: remove assignment from IS_ERR argument
  vfs: rename parent_ino to d_parent_ino and make it use RCU
  vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)
  stat: use vfs_empty_path() helper
  fs: new helper vfs_empty_path()
  fs: reflow may_create_in_sticky()
  vfs: remove redundant smp_mb for thp handling in do_dentry_open
  fuse: Use in_group_or_capable() helper
  f2fs: Use in_group_or_capable() helper
  fs: Export in_group_or_capable()
  vfs: reorder checks in may_create_in_sticky
  hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode()
  proc: Remove usage of the deprecated ida_simple_xx() API
  hfsplus: fix to avoid false alarm of circular locking
  Improve readability of copy_tree
  vfs: shave a branch in getname_flags
  vfs: retire user_path_at_empty and drop empty arg from getname_flags
  vfs: stop using user_path_at_empty in do_readlinkat
  tmpfs: don't interrupt fallocate with EINTR
  fs: don't block i_writecount during exec
  ...

4 files changed, 58 insertions, 39 deletions

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index bf53e3894aae..ea58843942b9 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -278,6 +278,8 @@ static inline unsigned d_count(const struct dentry *dentry)
 	return dentry->d_lockref.count;
 }
 
+ino_t d_parent_ino(struct dentry *dentry);
+
 /*
  * helper function for dentry_operations.d_dname() members
  */
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index bb37ad5cc954..893a1d21dc1c 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -158,6 +158,7 @@ struct fid {
 
 #define EXPORT_FH_CONNECTABLE	0x1 /* Encode file handle with parent */
 #define EXPORT_FH_FID		0x2 /* File handle may be non-decodeable */
+#define EXPORT_FH_DIR_ONLY	0x4 /* Only decode file handle for a directory */
 
 /**
  * struct export_operations - for nfsd to communicate with file systems
@@ -305,6 +306,7 @@ static inline int exportfs_encode_fid(struct inode *inode, struct fid *fid,
 extern struct dentry *exportfs_decode_fh_raw(struct vfsmount *mnt,
 					     struct fid *fid, int fh_len,
 					     int fileid_type,
+					     unsigned int flags,
 					     int (*acceptable)(void *, struct dentry *),
 					     void *context);
 extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0283cf366c2a..2fa06a4d197a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -660,9 +660,13 @@ struct inode {
 	};
 	dev_t			i_rdev;
 	loff_t			i_size;
-	struct timespec64	__i_atime;
-	struct timespec64	__i_mtime;
-	struct timespec64	__i_ctime; /* use inode_*_ctime accessors! */
+	time64_t		i_atime_sec;
+	time64_t		i_mtime_sec;
+	time64_t		i_ctime_sec;
+	u32			i_atime_nsec;
+	u32			i_mtime_nsec;
+	u32			i_ctime_nsec;
+	u32			i_generation;
 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
 	unsigned short          i_bytes;
 	u8			i_blkbits;
@@ -719,10 +723,10 @@ struct inode {
 		unsigned		i_dir_seq;
 	};
 
-	__u32			i_generation;
 
 #ifdef CONFIG_FSNOTIFY
 	__u32			i_fsnotify_mask; /* all events this inode cares about */
+	/* 32-bit hole reserved for expanding i_fsnotify_mask */
 	struct fsnotify_mark_connector __rcu	*i_fsnotify_marks;
 #endif
 
@@ -1538,23 +1542,27 @@ struct timespec64 inode_set_ctime_current(struct inode *inode);
 
 static inline time64_t inode_get_atime_sec(const struct inode *inode)
 {
-	return inode->__i_atime.tv_sec;
+	return inode->i_atime_sec;
 }
 
 static inline long inode_get_atime_nsec(const struct inode *inode)
 {
-	return inode->__i_atime.tv_nsec;
+	return inode->i_atime_nsec;
 }
 
 static inline struct timespec64 inode_get_atime(const struct inode *inode)
 {
-	return inode->__i_atime;
+	struct timespec64 ts = { .tv_sec  = inode_get_atime_sec(inode),
+				 .tv_nsec = inode_get_atime_nsec(inode) };
+
+	return ts;
 }
 
 static inline struct timespec64 inode_set_atime_to_ts(struct inode *inode,
 						      struct timespec64 ts)
 {
-	inode->__i_atime = ts;
+	inode->i_atime_sec = ts.tv_sec;
+	inode->i_atime_nsec = ts.tv_nsec;
 	return ts;
 }
 
@@ -1563,28 +1571,32 @@ static inline struct timespec64 inode_set_atime(struct inode *inode,
 {
 	struct timespec64 ts = { .tv_sec  = sec,
 				 .tv_nsec = nsec };
+
 	return inode_set_atime_to_ts(inode, ts);
 }
 
 static inline time64_t inode_get_mtime_sec(const struct inode *inode)
 {
-	return inode->__i_mtime.tv_sec;
+	return inode->i_mtime_sec;
 }
 
 static inline long inode_get_mtime_nsec(const struct inode *inode)
 {
-	return inode->__i_mtime.tv_nsec;
+	return inode->i_mtime_nsec;
 }
 
 static inline struct timespec64 inode_get_mtime(const struct inode *inode)
 {
-	return inode->__i_mtime;
+	struct timespec64 ts = { .tv_sec  = inode_get_mtime_sec(inode),
+				 .tv_nsec = inode_get_mtime_nsec(inode) };
+	return ts;
 }
 
 static inline struct timespec64 inode_set_mtime_to_ts(struct inode *inode,
 						      struct timespec64 ts)
 {
-	inode->__i_mtime = ts;
+	inode->i_mtime_sec = ts.tv_sec;
+	inode->i_mtime_nsec = ts.tv_nsec;
 	return ts;
 }
 
@@ -1598,23 +1610,27 @@ static inline struct timespec64 inode_set_mtime(struct inode *inode,
 
 static inline time64_t inode_get_ctime_sec(const struct inode *inode)
 {
-	return inode->__i_ctime.tv_sec;
+	return inode->i_ctime_sec;
 }
 
 static inline long inode_get_ctime_nsec(const struct inode *inode)
 {
-	return inode->__i_ctime.tv_nsec;
+	return inode->i_ctime_nsec;
 }
 
 static inline struct timespec64 inode_get_ctime(const struct inode *inode)
 {
-	return inode->__i_ctime;
+	struct timespec64 ts = { .tv_sec  = inode_get_ctime_sec(inode),
+				 .tv_nsec = inode_get_ctime_nsec(inode) };
+
+	return ts;
 }
 
 static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode,
 						      struct timespec64 ts)
 {
-	inode->__i_ctime = ts;
+	inode->i_ctime_sec = ts.tv_sec;
+	inode->i_ctime_nsec = ts.tv_nsec;
 	return ts;
 }
 
@@ -1926,6 +1942,8 @@ void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
 extern bool may_open_dev(const struct path *path);
 umode_t mode_strip_sgid(struct mnt_idmap *idmap,
 			const struct inode *dir, umode_t mode);
+bool in_group_or_capable(struct mnt_idmap *idmap,
+			 const struct inode *inode, vfsgid_t vfsgid);
 
 /*
  * This is the "filldir" function type, used by readdir() to let
@@ -2685,7 +2703,7 @@ static inline struct file *file_clone_open(struct file *file)
 }
 extern int filp_close(struct file *, fl_owner_t id);
 
-extern struct filename *getname_flags(const char __user *, int, int *);
+extern struct filename *getname_flags(const char __user *, int);
 extern struct filename *getname_uflags(const char __user *, int);
 extern struct filename *getname(const char __user *);
 extern struct filename *getname_kernel(const char *);
@@ -3436,20 +3454,6 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
 	return 0;
 }
 
-static inline ino_t parent_ino(struct dentry *dentry)
-{
-	ino_t res;
-
-	/*
-	 * Don't strictly need d_lock here? If the parent ino could change
-	 * then surely we'd have a deeper race in the caller?
-	 */
-	spin_lock(&dentry->d_lock);
-	res = dentry->d_parent->d_inode->i_ino;
-	spin_unlock(&dentry->d_lock);
-	return res;
-}
-
 /* Transaction based IO helpers */
 
 /*
@@ -3574,7 +3578,7 @@ static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
 {
 	return ctx->actor(ctx, "..", 2, ctx->pos,
-			  parent_ino(file->f_path.dentry), DT_DIR);
+			  d_parent_ino(file->f_path.dentry), DT_DIR);
 }
 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
 {
@@ -3613,4 +3617,21 @@ extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
 extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
 			   int advice);
 
+static inline bool vfs_empty_path(int dfd, const char __user *path)
+{
+	char c;
+
+	if (dfd < 0)
+		return false;
+
+	/* We now allow NULL to be used for empty path. */
+	if (!path)
+		return true;
+
+	if (unlikely(get_user(c, path)))
+		return false;
+
+	return !c;
+}
+
 #endif /* _LINUX_FS_H */
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 967aa9ea9f96..8ec8fed3bce8 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -50,13 +50,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT};
 
 extern int path_pts(struct path *path);
 
-extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
-
-static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
-		 struct path *path)
-{
-	return user_path_at_empty(dfd, name, flags, path, NULL);
-}
+extern int user_path_at(int, const char __user *, unsigned, struct path *);
 
 struct dentry *lookup_one_qstr_excl(const struct qstr *name,
 				    struct dentry *base,