Merge tag 'fuse-update-4.20' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:
 "As well as the usual bug fixes, this adds the following new features:

   - cached readdir and readlink

   - max I/O size increased from 128k to 1M

   - improved performance and scalability of request queues

   - copy_file_range support

  The only non-fuse bits are trivial cleanups of macros in
  <linux/bitops.h>"

* tag 'fuse-update-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (31 commits)
  fuse: enable caching of symlinks
  fuse: only invalidate atime in direct read
  fuse: don't need GETATTR after every READ
  fuse: allow fine grained attr cache invaldation
  bitops: protect variables in bit_clear_unless() macro
  bitops: protect variables in set_mask_bits() macro
  fuse: realloc page array
  fuse: add max_pages to init_out
  fuse: allocate page array more efficiently
  fuse: reduce size of struct fuse_inode
  fuse: use iversion for readdir cache verification
  fuse: use mtime for readdir cache verification
  fuse: add readdir cache version
  fuse: allow using readdir cache
  fuse: allow caching readdir
  fuse: extract fuse_emit() helper
  fuse: add FOPEN_CACHE_DIR
  fuse: split out readdir.c
  fuse: Use hash table to link processing request
  fuse: kill req->intr_unique
  ...

fs/fuse/Makefile

@@ -5,4 +5,4 @@
 obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 
-fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o
+fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o

fs/fuse/control.c

@@ -107,7 +107,7 @@ static ssize_t fuse_conn_max_background_read(struct file *file,
 	if (!fc)
 		return 0;
 
-	val = fc->max_background;
+	val = READ_ONCE(fc->max_background);
 	fuse_conn_put(fc);
 
 	return fuse_conn_limit_read(file, buf, len, ppos, val);
@@ -125,7 +125,12 @@ static ssize_t fuse_conn_max_background_write(struct file *file,
 	if (ret > 0) {
 		struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
 		if (fc) {
+			spin_lock(&fc->bg_lock);
 			fc->max_background = val;
+			fc->blocked = fc->num_background >= fc->max_background;
+			if (!fc->blocked)
+				wake_up(&fc->blocked_waitq);
+			spin_unlock(&fc->bg_lock);
 			fuse_conn_put(fc);
 		}
 	}
@@ -144,7 +149,7 @@ static ssize_t fuse_conn_congestion_threshold_read(struct file *file,
 	if (!fc)
 		return 0;
 
-	val = fc->congestion_threshold;
+	val = READ_ONCE(fc->congestion_threshold);
 	fuse_conn_put(fc);
 
 	return fuse_conn_limit_read(file, buf, len, ppos, val);
@@ -155,18 +160,31 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
 						    size_t count, loff_t *ppos)
 {
 	unsigned uninitialized_var(val);
+	struct fuse_conn *fc;
 	ssize_t ret;
 
 	ret = fuse_conn_limit_write(file, buf, count, ppos, &val,
 				    max_user_congthresh);
-	if (ret > 0) {
-		struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
-		if (fc) {
-			fc->congestion_threshold = val;
-			fuse_conn_put(fc);
+	if (ret <= 0)
+		goto out;
+	fc = fuse_ctl_file_conn_get(file);
+	if (!fc)
+		goto out;
+
+	spin_lock(&fc->bg_lock);
+	fc->congestion_threshold = val;
+	if (fc->sb) {
+		if (fc->num_background < fc->congestion_threshold) {
+			clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
+			clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
+		} else {
+			set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
+			set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
 		}
 	}
-
+	spin_unlock(&fc->bg_lock);
+	fuse_conn_put(fc);
+out:
 	return ret;
 }