Merge tag 'fuse-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Revert non-waiting FLUSH due to a regression

 - Fix a lookup counter leak in readdirplus

 - Add an option to allow shared mmaps in no-cache mode

 - Add btime support and statx intrastructure to the protocol

 - Invalidate positive/negative dentry on failed create/delete

* tag 'fuse-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: conditionally fill kstat in fuse_do_statx()
  fuse: invalidate dentry on EEXIST creates or ENOENT deletes
  fuse: cache btime
  fuse: implement statx
  fuse: add ATTR_TIMEOUT macro
  fuse: add STATX request
  fuse: handle empty request_mask in statx
  fuse: write back dirty pages before direct write in direct_io_relax mode
  fuse: add a new fuse init flag to relax restrictions in no cache mode
  fuse: invalidate page cache pages before direct write
  fuse: nlookup missing decrement in fuse_direntplus_link
  Revert "fuse: in fuse_flush only wait if someone wants the return code"

fs/fuse/dir.c

@@ -92,7 +92,7 @@ static void fuse_dentry_settime(struct dentry *dentry, u64 time)
 /*
  * Calculate the time in jiffies until a dentry/attributes are valid
  */
-static u64 time_to_jiffies(u64 sec, u32 nsec)
+u64 fuse_time_to_jiffies(u64 sec, u32 nsec)
 {
 	if (sec || nsec) {
 		struct timespec64 ts = {
@@ -112,17 +112,7 @@ static u64 time_to_jiffies(u64 sec, u32 nsec)
 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o)
 {
 	fuse_dentry_settime(entry,
-		time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
-}
-
-static u64 attr_timeout(struct fuse_attr_out *o)
-{
-	return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
-}
-
-u64 entry_attr_timeout(struct fuse_entry_out *o)
-{
-	return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+		fuse_time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
 }
 
 void fuse_invalidate_attr_mask(struct inode *inode, u32 mask)
@@ -265,8 +255,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 			goto invalid;
 
 		forget_all_cached_acls(inode);
-		fuse_change_attributes(inode, &outarg.attr,
-				       entry_attr_timeout(&outarg),
+		fuse_change_attributes(inode, &outarg.attr, NULL,
+				       ATTR_TIMEOUT(&outarg),
 				       attr_version);
 		fuse_change_entry_timeout(entry, &outarg);
 	} else if (inode) {
@@ -360,10 +350,14 @@ int fuse_valid_type(int m)
 		S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
 }
 
+static bool fuse_valid_size(u64 size)
+{
+	return size <= LLONG_MAX;
+}
+
 bool fuse_invalid_attr(struct fuse_attr *attr)
 {
-	return !fuse_valid_type(attr->mode) ||
-		attr->size > LLONG_MAX;
+	return !fuse_valid_type(attr->mode) || !fuse_valid_size(attr->size);
 }
 
 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
@@ -399,7 +393,7 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name
 		goto out_put_forget;
 
 	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
-			   &outarg->attr, entry_attr_timeout(outarg),
+			   &outarg->attr, ATTR_TIMEOUT(outarg),
 			   attr_version);
 	err = -ENOMEM;
 	if (!*inode) {
@@ -686,7 +680,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	ff->nodeid = outentry.nodeid;
 	ff->open_flags = outopen.open_flags;
 	inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
-			  &outentry.attr, entry_attr_timeout(&outentry), 0);
+			  &outentry.attr, ATTR_TIMEOUT(&outentry), 0);
 	if (!inode) {
 		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
 		fuse_sync_release(NULL, ff, flags);
@@ -755,7 +749,8 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 	if (err == -ENOSYS) {
 		fc->no_create = 1;
 		goto mknod;
-	}
+	} else if (err == -EEXIST)
+		fuse_invalidate_entry(entry);
 out_dput:
 	dput(res);
 	return err;
@@ -813,7 +808,7 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 		goto out_put_forget_req;
 
 	inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
-			  &outarg.attr, entry_attr_timeout(&outarg), 0);
+			  &outarg.attr, ATTR_TIMEOUT(&outarg), 0);
 	if (!inode) {
 		fuse_queue_forget(fm->fc, forget, outarg.nodeid, 1);
 		return -ENOMEM;
@@ -835,6 +830,8 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
 	return 0;
 
  out_put_forget_req:
+	if (err == -EEXIST)
+		fuse_invalidate_entry(entry);
 	kfree(forget);
 	return err;
 }
@@ -986,7 +983,7 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry)
 	if (!err) {
 		fuse_dir_changed(dir);
 		fuse_entry_unlinked(entry);
-	} else if (err == -EINTR)
+	} else if (err == -EINTR || err == -ENOENT)
 		fuse_invalidate_entry(entry);
 	return err;
 }
@@ -1009,7 +1006,7 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
 	if (!err) {
 		fuse_dir_changed(dir);
 		fuse_entry_unlinked(entry);
-	} else if (err == -EINTR)
+	} else if (err == -EINTR || err == -ENOENT)
 		fuse_invalidate_entry(entry);
 	return err;
 }
@@ -1050,7 +1047,7 @@ static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
 		/* newent will end up negative */
 		if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent))
 			fuse_entry_unlinked(newent);
-	} else if (err == -EINTR) {
+	} else if (err == -EINTR || err == -ENOENT) {
 		/* If request was interrupted, DEITY only knows if the
 		   rename actually took place.  If the invalidation
 		   fails (e.g. some process has CWD under the renamed
@@ -1153,6 +1150,87 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
 	stat->blksize = 1 << blkbits;
 }
 
+static void fuse_statx_to_attr(struct fuse_statx *sx, struct fuse_attr *attr)
+{
+	memset(attr, 0, sizeof(*attr));
+	attr->ino = sx->ino;
+	attr->size = sx->size;
+	attr->blocks = sx->blocks;
+	attr->atime = sx->atime.tv_sec;
+	attr->mtime = sx->mtime.tv_sec;
+	attr->ctime = sx->ctime.tv_sec;
+	attr->atimensec = sx->atime.tv_nsec;
+	attr->mtimensec = sx->mtime.tv_nsec;
+	attr->ctimensec = sx->ctime.tv_nsec;
+	attr->mode = sx->mode;
+	attr->nlink = sx->nlink;
+	attr->uid = sx->uid;
+	attr->gid = sx->gid;
+	attr->rdev = new_encode_dev(MKDEV(sx->rdev_major, sx->rdev_minor));
+	attr->blksize = sx->blksize;
+}
+
+static int fuse_do_statx(struct inode *inode, struct file *file,
+			 struct kstat *stat)
+{
+	int err;
+	struct fuse_attr attr;
+	struct fuse_statx *sx;
+	struct fuse_statx_in inarg;
+	struct fuse_statx_out outarg;
+	struct fuse_mount *fm = get_fuse_mount(inode);
+	u64 attr_version = fuse_get_attr_version(fm->fc);
+	FUSE_ARGS(args);
+
+	memset(&inarg, 0, sizeof(inarg));
+	memset(&outarg, 0, sizeof(outarg));
+	/* Directories have separate file-handle space */
+	if (file && S_ISREG(inode->i_mode)) {
+		struct fuse_file *ff = file->private_data;
+
+		inarg.getattr_flags |= FUSE_GETATTR_FH;
+		inarg.fh = ff->fh;
+	}
+	/* For now leave sync hints as the default, request all stats. */
+	inarg.sx_flags = 0;
+	inarg.sx_mask = STATX_BASIC_STATS | STATX_BTIME;
+	args.opcode = FUSE_STATX;
+	args.nodeid = get_node_id(inode);
+	args.in_numargs = 1;
+	args.in_args[0].size = sizeof(inarg);
+	args.in_args[0].value = &inarg;
+	args.out_numargs = 1;
+	args.out_args[0].size = sizeof(outarg);
+	args.out_args[0].value = &outarg;
+	err = fuse_simple_request(fm, &args);
+	if (err)
+		return err;
+
+	sx = &outarg.stat;
+	if (((sx->mask & STATX_SIZE) && !fuse_valid_size(sx->size)) ||
+	    ((sx->mask & STATX_TYPE) && (!fuse_valid_type(sx->mode) ||
+					 inode_wrong_type(inode, sx->mode)))) {
+		make_bad_inode(inode);
+		return -EIO;
+	}
+
+	fuse_statx_to_attr(&outarg.stat, &attr);
+	if ((sx->mask & STATX_BASIC_STATS) == STATX_BASIC_STATS) {
+		fuse_change_attributes(inode, &attr, &outarg.stat,
+				       ATTR_TIMEOUT(&outarg), attr_version);
+	}
+
+	if (stat) {
+		stat->result_mask = sx->mask & (STATX_BASIC_STATS | STATX_BTIME);
+		stat->btime.tv_sec = sx->btime.tv_sec;
+		stat->btime.tv_nsec = min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1);
+		fuse_fillattr(inode, &attr, stat);
+		stat->result_mask |= STATX_TYPE;
+	}
+
+	return 0;
+}
+
 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 			   struct file *file)
 {
@@ -1189,8 +1267,8 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 			fuse_make_bad(inode);
 			err = -EIO;
 		} else {
-			fuse_change_attributes(inode, &outarg.attr,
-					       attr_timeout(&outarg),
+			fuse_change_attributes(inode, &outarg.attr, NULL,
+					       ATTR_TIMEOUT(&outarg),
 					       attr_version);
 			if (stat)
 				fuse_fillattr(inode, &outarg.attr, stat);
@@ -1204,12 +1282,22 @@ static int fuse_update_get_attr(struct inode *inode, struct file *file,
 				unsigned int flags)
 {
 	struct fuse_inode *fi = get_fuse_inode(inode);
+	struct fuse_conn *fc = get_fuse_conn(inode);
 	int err = 0;
 	bool sync;
 	u32 inval_mask = READ_ONCE(fi->inval_mask);
 	u32 cache_mask = fuse_get_cache_mask(inode);
 
-	if (flags & AT_STATX_FORCE_SYNC)
+
+	/* FUSE only supports basic stats and possibly btime */
+	request_mask &= STATX_BASIC_STATS | STATX_BTIME;
+retry:
+	if (fc->no_statx)
+		request_mask &= STATX_BASIC_STATS;
+
+	if (!request_mask)
+		sync = false;
+	else if (flags & AT_STATX_FORCE_SYNC)
 		sync = true;
 	else if (flags & AT_STATX_DONT_SYNC)
 		sync = false;
@@ -1220,11 +1308,24 @@ static int fuse_update_get_attr(struct inode *inode, struct file *file,
 
 	if (sync) {
 		forget_all_cached_acls(inode);
+		/* Try statx if BTIME is requested */
+		if (!fc->no_statx && (request_mask & ~STATX_BASIC_STATS)) {
+			err = fuse_do_statx(inode, file, stat);
+			if (err == -ENOSYS) {
+				fc->no_statx = 1;
+				goto retry;
+			}
+		} else {
 			err = fuse_do_getattr(inode, stat, file);
+		}
 	} else if (stat) {
 		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
 		stat->mode = fi->orig_i_mode;
 		stat->ino = fi->orig_ino;
+		if (test_bit(FUSE_I_BTIME, &fi->state)) {
+			stat->btime = fi->i_btime;
+			stat->result_mask |= STATX_BTIME;
+		}
 	}
 
 	return err;
@@ -1861,8 +1962,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 		/* FIXME: clear I_DIRTY_SYNC? */
 	}
 
-	fuse_change_attributes_common(inode, &outarg.attr,
-				      attr_timeout(&outarg),
+	fuse_change_attributes_common(inode, &outarg.attr, NULL,
+				      ATTR_TIMEOUT(&outarg),
 				      fuse_get_cache_mask(inode));
 	oldsize = inode->i_size;
 	/* see the comment in fuse_change_attributes() */

fs/fuse/file.c

@@ -19,7 +19,6 @@
 #include <linux/uio.h>
 #include <linux/fs.h>
 #include <linux/filelock.h>
-#include <linux/file.h>
 
 static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
 			  unsigned int open_flags, int opcode,
@@ -479,36 +478,48 @@ static void fuse_sync_writes(struct inode *inode)
 	fuse_release_nowrite(inode);
 }
 
-struct fuse_flush_args {
-	struct fuse_args args;
-	struct fuse_flush_in inarg;
-	struct work_struct work;
-	struct file *file;
-};
-
-static int fuse_do_flush(struct fuse_flush_args *fa)
+static int fuse_flush(struct file *file, fl_owner_t id)
 {
-	int err;
-	struct inode *inode = file_inode(fa->file);
+	struct inode *inode = file_inode(file);
 	struct fuse_mount *fm = get_fuse_mount(inode);
+	struct fuse_file *ff = file->private_data;
+	struct fuse_flush_in inarg;
+	FUSE_ARGS(args);
+	int err;
+
+	if (fuse_is_bad(inode))
+		return -EIO;
+
+	if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
+		return 0;
 
 	err = write_inode_now(inode, 1);
 	if (err)
-		goto out;
+		return err;
 
 	inode_lock(inode);
 	fuse_sync_writes(inode);
 	inode_unlock(inode);
 
-	err = filemap_check_errors(fa->file->f_mapping);
+	err = filemap_check_errors(file->f_mapping);
 	if (err)
-		goto out;
+		return err;
 
 	err = 0;
 	if (fm->fc->no_flush)
 		goto inval_attr_out;
 
-	err = fuse_simple_request(fm, &fa->args);
+	memset(&inarg, 0, sizeof(inarg));
+	inarg.fh = ff->fh;
+	inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
+	args.opcode = FUSE_FLUSH;
+	args.nodeid = get_node_id(inode);
+	args.in_numargs = 1;
+	args.in_args[0].size = sizeof(inarg);
+	args.in_args[0].value = &inarg;
+	args.force = true;
+
+	err = fuse_simple_request(fm, &args);
 	if (err == -ENOSYS) {
 		fm->fc->no_flush = 1;
 		err = 0;
@@ -521,57 +532,9 @@ static int fuse_do_flush(struct fuse_flush_args *fa)
 	 */
 	if (!err && fm->fc->writeback_cache)
 		fuse_invalidate_attr_mask(inode, STATX_BLOCKS);
-
-out:
-	fput(fa->file);
-	kfree(fa);
 	return err;
 }
 
-static void fuse_flush_async(struct work_struct *work)
-{
-	struct fuse_flush_args *fa = container_of(work, typeof(*fa), work);
-
-	fuse_do_flush(fa);
-}
-
-static int fuse_flush(struct file *file, fl_owner_t id)
-{
-	struct fuse_flush_args *fa;
-	struct inode *inode = file_inode(file);
-	struct fuse_mount *fm = get_fuse_mount(inode);
-	struct fuse_file *ff = file->private_data;
-
-	if (fuse_is_bad(inode))
-		return -EIO;
-
-	if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
-		return 0;
-
-	fa = kzalloc(sizeof(*fa), GFP_KERNEL);
-	if (!fa)
-		return -ENOMEM;
-
-	fa->inarg.fh = ff->fh;
-	fa->inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
-	fa->args.opcode = FUSE_FLUSH;
-	fa->args.nodeid = get_node_id(inode);
-	fa->args.in_numargs = 1;
-	fa->args.in_args[0].size = sizeof(fa->inarg);
-	fa->args.in_args[0].value = &fa->inarg;
-	fa->args.force = true;
-	fa->file = get_file(file);
-
-	/* Don't wait if the task is exiting */
-	if (current->flags & PF_EXITING) {
-		INIT_WORK(&fa->work, fuse_flush_async);
-		schedule_work(&fa->work);
-		return 0;
-	}
-
-	return fuse_do_flush(fa);
-}
-
 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 		      int datasync, int opcode)
 {
@@ -1465,7 +1428,8 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 	int write = flags & FUSE_DIO_WRITE;
 	int cuse = flags & FUSE_DIO_CUSE;
 	struct file *file = io->iocb->ki_filp;
-	struct inode *inode = file->f_mapping->host;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
 	struct fuse_file *ff = file->private_data;
 	struct fuse_conn *fc = ff->fm->fc;
 	size_t nmax = write ? fc->max_write : fc->max_read;
@@ -1477,12 +1441,20 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 	int err = 0;
 	struct fuse_io_args *ia;
 	unsigned int max_pages;
+	bool fopen_direct_io = ff->open_flags & FOPEN_DIRECT_IO;
 
 	max_pages = iov_iter_npages(iter, fc->max_pages);
 	ia = fuse_io_alloc(io, max_pages);
 	if (!ia)
 		return -ENOMEM;
 
+	if (fopen_direct_io && fc->direct_io_relax) {
+		res = filemap_write_and_wait_range(mapping, pos, pos + count - 1);
+		if (res) {
+			fuse_io_free(ia);
+			return res;
+		}
+	}
 	if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
 		if (!write)
 			inode_lock(inode);
@@ -1491,6 +1463,14 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
 			inode_unlock(inode);
 	}
 
+	if (fopen_direct_io && write) {
+		res = invalidate_inode_pages2_range(mapping, idx_from, idx_to);
+		if (res) {
+			fuse_io_free(ia);
+			return res;
+		}
+	}
+
 	io->should_dirty = !write && user_backed_iter(iter);
 	while (count) {
 		ssize_t nres;
@@ -2478,14 +2458,17 @@ static const struct vm_operations_struct fuse_file_vm_ops = {
 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct fuse_file *ff = file->private_data;
+	struct fuse_conn *fc = ff->fm->fc;
 
 	/* DAX mmap is superior to direct_io mmap */
 	if (FUSE_IS_DAX(file_inode(file)))
 		return fuse_dax_mmap(file, vma);
 
 	if (ff->open_flags & FOPEN_DIRECT_IO) {
-		/* Can't provide the coherency needed for MAP_SHARED */
-		if (vma->vm_flags & VM_MAYSHARE)
+		/* Can't provide the coherency needed for MAP_SHARED
+		 * if FUSE_DIRECT_IO_RELAX isn't set.
+		 */
+		if ((vma->vm_flags & VM_MAYSHARE) && !fc->direct_io_relax)
 			return -ENODEV;
 
 		invalidate_inode_pages2(file->f_mapping);

fs/fuse/fuse_i.h

@@ -88,6 +88,9 @@ struct fuse_inode {
 	    preserve the original mode */
 	umode_t orig_i_mode;
 
+	/* Cache birthtime */
+	struct timespec64 i_btime;
+
 	/** 64 bit inode number */
 	u64 orig_ino;
 
@@ -167,6 +170,8 @@ enum {
 	FUSE_I_SIZE_UNSTABLE,
 	/* Bad inode */
 	FUSE_I_BAD,
+	/* Has btime */
+	FUSE_I_BTIME,
 };
 
 struct fuse_conn;
@@ -792,6 +797,12 @@ struct fuse_conn {
 	/* Is tmpfile not implemented by fs? */
 	unsigned int no_tmpfile:1;
 
+	/* relax restrictions in FOPEN_DIRECT_IO mode */
+	unsigned int direct_io_relax:1;
+
+	/* Is statx not implemented by fs? */
+	unsigned int no_statx:1;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 
@@ -1058,9 +1069,11 @@ void fuse_init_symlink(struct inode *inode);
  * Change attributes of an inode
  */
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			    struct fuse_statx *sx,
 			    u64 attr_valid, u64 attr_version);
 
 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
+				   struct fuse_statx *sx,
 				   u64 attr_valid, u32 cache_mask);
 
 u32 fuse_get_cache_mask(struct inode *inode);
@@ -1111,7 +1124,10 @@ void fuse_invalidate_entry_cache(struct dentry *entry);
 
 void fuse_invalidate_atime(struct inode *inode);
 
-u64 entry_attr_timeout(struct fuse_entry_out *o);
+u64 fuse_time_to_jiffies(u64 sec, u32 nsec);
+#define ATTR_TIMEOUT(o) \
+	fuse_time_to_jiffies((o)->attr_valid, (o)->attr_valid_nsec)
+
 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
 
 /**

fs/fuse/inode.c

@@ -77,7 +77,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
 		return NULL;
 
 	fi->i_time = 0;
-	fi->inval_mask = 0;
+	fi->inval_mask = ~0;
 	fi->nodeid = 0;
 	fi->nlookup = 0;
 	fi->attr_version = 0;
@@ -163,6 +163,7 @@ static ino_t fuse_squash_ino(u64 ino64)
 }
 
 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
+				   struct fuse_statx *sx,
 				   u64 attr_valid, u32 cache_mask)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
@@ -172,7 +173,8 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 
 	fi->attr_version = atomic64_inc_return(&fc->attr_version);
 	fi->i_time = attr_valid;
-	WRITE_ONCE(fi->inval_mask, 0);
+	/* Clear basic stats from invalid mask */
+	set_mask_bits(&fi->inval_mask, STATX_BASIC_STATS, 0);
 
 	inode->i_ino     = fuse_squash_ino(attr->ino);
 	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
@@ -196,6 +198,25 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 	if (!(cache_mask & STATX_CTIME)) {
 		inode_set_ctime(inode, attr->ctime, attr->ctimensec);
 	}
+	if (sx) {
+		/* Sanitize nsecs */
+		sx->btime.tv_nsec =
+			min_t(u32, sx->btime.tv_nsec, NSEC_PER_SEC - 1);
+
+		/*
+		 * Btime has been queried, cache is valid (whether or not btime
+		 * is available or not) so clear STATX_BTIME from inval_mask.
+		 *
+		 * Availability of the btime attribute is indicated in
+		 * FUSE_I_BTIME
+		 */
+		set_mask_bits(&fi->inval_mask, STATX_BTIME, 0);
+		if (sx->mask & STATX_BTIME) {
+			set_bit(FUSE_I_BTIME, &fi->state);
+			fi->i_btime.tv_sec = sx->btime.tv_sec;
+			fi->i_btime.tv_nsec = sx->btime.tv_nsec;
+		}
+	}
 
 	if (attr->blksize != 0)
 		inode->i_blkbits = ilog2(attr->blksize);
@@ -235,6 +256,7 @@ u32 fuse_get_cache_mask(struct inode *inode)
 }
 
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			    struct fuse_statx *sx,
 			    u64 attr_valid, u64 attr_version)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
@@ -269,7 +291,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 	}
 
 	old_mtime = inode->i_mtime;
-	fuse_change_attributes_common(inode, attr, attr_valid, cache_mask);
+	fuse_change_attributes_common(inode, attr, sx, attr_valid, cache_mask);
 
 	oldsize = inode->i_size;
 	/*
@@ -406,7 +428,7 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 	spin_lock(&fi->lock);
 	fi->nlookup++;
 	spin_unlock(&fi->lock);
-	fuse_change_attributes(inode, attr, attr_valid, attr_version);
+	fuse_change_attributes(inode, attr, NULL, attr_valid, attr_version);
 
 	return inode;
 }
@@ -1210,6 +1232,8 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
 				fc->init_security = 1;
 			if (flags & FUSE_CREATE_SUPP_GROUP)
 				fc->create_supp_group = 1;
+			if (flags & FUSE_DIRECT_IO_RELAX)
+				fc->direct_io_relax = 1;
 		} else {
 			ra_pages = fc->max_read / PAGE_SIZE;
 			fc->no_lock = 1;
@@ -1256,7 +1280,7 @@ void fuse_send_init(struct fuse_mount *fm)
 		FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA |
 		FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
 		FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP |
-		FUSE_HAS_EXPIRE_ONLY;
+		FUSE_HAS_EXPIRE_ONLY | FUSE_DIRECT_IO_RELAX;
 #ifdef CONFIG_FUSE_DAX
 	if (fm->fc->dax)
 		flags |= FUSE_MAP_ALIGNMENT;

fs/fuse/readdir.c

@@ -223,8 +223,8 @@ static int fuse_direntplus_link(struct file *file,
 		spin_unlock(&fi->lock);
 
 		forget_all_cached_acls(inode);
-		fuse_change_attributes(inode, &o->attr,
-				       entry_attr_timeout(o),
+		fuse_change_attributes(inode, &o->attr, NULL,
+				       ATTR_TIMEOUT(o),
 				       attr_version);
 		/*
 		 * The other branch comes via fuse_iget()
@@ -232,7 +232,7 @@ static int fuse_direntplus_link(struct file *file,
 		 */
 	} else {
 		inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
-				  &o->attr, entry_attr_timeout(o),
+				  &o->attr, ATTR_TIMEOUT(o),
 				  attr_version);
 		if (!inode)
 			inode = ERR_PTR(-ENOMEM);
@@ -243,9 +243,17 @@ static int fuse_direntplus_link(struct file *file,
 			dput(dentry);
 			dentry = alias;
 		}
-		if (IS_ERR(dentry))
+		if (IS_ERR(dentry)) {
+			if (!IS_ERR(inode)) {
+				struct fuse_inode *fi = get_fuse_inode(inode);
+
+				spin_lock(&fi->lock);
+				fi->nlookup--;
+				spin_unlock(&fi->lock);
+			}
 			return PTR_ERR(dentry);
 		}
+	}
 	if (fc->readdirplus_auto)
 		set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
 	fuse_change_entry_timeout(dentry, o);

include/uapi/linux/fuse.h

@@ -207,6 +207,10 @@
  *  - add FUSE_EXT_GROUPS
  *  - add FUSE_CREATE_SUPP_GROUP
  *  - add FUSE_HAS_EXPIRE_ONLY
+ *
+ *  7.39
+ *  - add FUSE_DIRECT_IO_RELAX
+ *  - add FUSE_STATX and related structures
  */
 
 #ifndef _LINUX_FUSE_H
@@ -242,7 +246,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 38
+#define FUSE_KERNEL_MINOR_VERSION 39
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -269,6 +273,40 @@ struct fuse_attr {
 	uint32_t	flags;
 };
 
+/*
+ * The following structures are bit-for-bit compatible with the statx(2) ABI in
+ * Linux.
+ */
+struct fuse_sx_time {
+	int64_t		tv_sec;
+	uint32_t	tv_nsec;
+	int32_t		__reserved;
+};
+
+struct fuse_statx {
+	uint32_t	mask;
+	uint32_t	blksize;
+	uint64_t	attributes;
+	uint32_t	nlink;
+	uint32_t	uid;
+	uint32_t	gid;
+	uint16_t	mode;
+	uint16_t	__spare0[1];
+	uint64_t	ino;
+	uint64_t	size;
+	uint64_t	blocks;
+	uint64_t	attributes_mask;
+	struct fuse_sx_time	atime;
+	struct fuse_sx_time	btime;
+	struct fuse_sx_time	ctime;
+	struct fuse_sx_time	mtime;
+	uint32_t	rdev_major;
+	uint32_t	rdev_minor;
+	uint32_t	dev_major;
+	uint32_t	dev_minor;
+	uint64_t	__spare2[14];
+};
+
 struct fuse_kstatfs {
 	uint64_t	blocks;
 	uint64_t	bfree;
@@ -371,6 +409,8 @@ struct fuse_file_lock {
  * FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir,
  *			symlink and mknod (single group that matches parent)
  * FUSE_HAS_EXPIRE_ONLY: kernel supports expiry-only entry invalidation
+ * FUSE_DIRECT_IO_RELAX: relax restrictions in FOPEN_DIRECT_IO mode, for now
+ *                       allow shared mmap
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -409,6 +449,7 @@ struct fuse_file_lock {
 #define FUSE_HAS_INODE_DAX	(1ULL << 33)
 #define FUSE_CREATE_SUPP_GROUP	(1ULL << 34)
 #define FUSE_HAS_EXPIRE_ONLY	(1ULL << 35)
+#define FUSE_DIRECT_IO_RELAX	(1ULL << 36)
 
 /**
  * CUSE INIT request/reply flags
@@ -575,6 +616,7 @@ enum fuse_opcode {
 	FUSE_REMOVEMAPPING	= 49,
 	FUSE_SYNCFS		= 50,
 	FUSE_TMPFILE		= 51,
+	FUSE_STATX		= 52,
 
 	/* CUSE specific operations */
 	CUSE_INIT		= 4096,
@@ -639,6 +681,22 @@ struct fuse_attr_out {
 	struct fuse_attr attr;
 };
 
+struct fuse_statx_in {
+	uint32_t	getattr_flags;
+	uint32_t	reserved;
+	uint64_t	fh;
+	uint32_t	sx_flags;
+	uint32_t	sx_mask;
+};
+
+struct fuse_statx_out {
+	uint64_t	attr_valid;	/* Cache timeout for the attributes */
+	uint32_t	attr_valid_nsec;
+	uint32_t	flags;
+	uint64_t	spare[2];
+	struct fuse_statx stat;
+};
+
 #define FUSE_COMPAT_MKNOD_IN_SIZE 8
 
 struct fuse_mknod_in {