3 files changed, 40 insertions, 10 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 93d8d6c..aba15f1 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -703,13 +703,16 @@ static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 				  unsigned long nr_segs, loff_t pos)
 {
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
+	struct fuse_conn *fc = get_fuse_conn(inode);
 
-	if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
+	/*
+	 * In auto invalidate mode, always update attributes on read.
+	 * Otherwise, only update if we attempt to read past EOF (to ensure
+	 * i_size is up to date).
+	 */
+	if (fc->auto_inval_data ||
+	    (pos + iov_length(iov, nr_segs) > i_size_read(inode))) {
 		int err;
-		/*
-		 * If trying to read past EOF, make sure the i_size
-		 * attribute is up-to-date.
-		 */
 		err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
 		if (err)
 			return err;
@@ -1700,7 +1703,7 @@ static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
 	size_t n;
 	u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
 
-	for (n = 0; n < count; n++) {
+	for (n = 0; n < count; n++, iov++) {
 		if (iov->iov_len > (size_t) max)
 			return -ENOMEM;
 		max -= iov->iov_len;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 771fb63..e24dd74 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -484,6 +484,9 @@ struct fuse_conn {
 	/** Is fallocate not implemented by fs? */
 	unsigned no_fallocate:1;
 
+	/** Use enhanced/automatic page cache invalidation. */
+	unsigned auto_inval_data:1;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 1cd6165..ce0a283 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -197,6 +197,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_inode *fi = get_fuse_inode(inode);
 	loff_t oldsize;
+	struct timespec old_mtime;
 
 	spin_lock(&fc->lock);
 	if (attr_version != 0 && fi->attr_version > attr_version) {
@@ -204,15 +205,35 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 		return;
 	}
 
+	old_mtime = inode->i_mtime;
 	fuse_change_attributes_common(inode, attr, attr_valid);
 
 	oldsize = inode->i_size;
 	i_size_write(inode, attr->size);
 	spin_unlock(&fc->lock);
 
-	if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
-		truncate_pagecache(inode, oldsize, attr->size);
-		invalidate_inode_pages2(inode->i_mapping);
+	if (S_ISREG(inode->i_mode)) {
+		bool inval = false;
+
+		if (oldsize != attr->size) {
+			truncate_pagecache(inode, oldsize, attr->size);
+			inval = true;
+		} else if (fc->auto_inval_data) {
+			struct timespec new_mtime = {
+				.tv_sec = attr->mtime,
+				.tv_nsec = attr->mtimensec,
+			};
+
+			/*
+			 * Auto inval mode also checks and invalidates if mtime
+			 * has changed.
+			 */
+			if (!timespec_equal(&old_mtime, &new_mtime))
+				inval = true;
+		}
+
+		if (inval)
+			invalidate_inode_pages2(inode->i_mapping);
 	}
 }
 
@@ -834,6 +855,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 				fc->big_writes = 1;
 			if (arg->flags & FUSE_DONT_MASK)
 				fc->dont_mask = 1;
+			if (arg->flags & FUSE_AUTO_INVAL_DATA)
+				fc->auto_inval_data = 1;
 		} else {
 			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 			fc->no_lock = 1;
@@ -859,7 +882,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 		FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
-		FUSE_FLOCK_LOCKS;
+		FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
+		FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA;
 	req->in.h.opcode = FUSE_INIT;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(*arg);