orangefs: a fix and two cleanups and a merge conflict

Fix: Christoph Hellwig noticed that some logic I added to
      orangefs_file_read_iter introduced a race condition, so he
      sent a reversion patch. I had to modify his patch since
      reverting at this point broke Orangefs.
 
 Cleanup 1: Christoph Hellwig noticed that we were doing some unnecessary
            work in orangefs_flush, so he sent in a patch that removed
            the un-needed code.
 
 Cleanup 2: Al Viro told me he had trouble building Orangefs. Orangefs
            should be easy to build, even for Al :-). I looked back
            at the test server build notes in orangefs.txt, just in case
            that's where the trouble really is, and found a couple of
            typos and made a couple of clarifications.
 
 Merge Conflict: Stephen Rothwell reported that my modifications to
                 orangefs.txt caused a merge conflict with orangefs.rst
                 in Linux Next. I wasn't sure what to do, so I asked,
                 and Jonathan Corbet said not to worry about it and
                 just to report it to Linus.
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Merge tag 'for-linus-5.7-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux

Pull orangefs updates from Mike Marshall:
 "A fix and two cleanups.

  Fix:

   - Christoph Hellwig noticed that some logic I added to
     orangefs_file_read_iter introduced a race condition, so he sent a
     reversion patch. I had to modify his patch since reverting at this
     point broke Orangefs.

  Cleanups:

   - Christoph Hellwig noticed that we were doing some unnecessary work
     in orangefs_flush, so he sent in a patch that removed the un-needed
     code.

   - Al Viro told me he had trouble building Orangefs. Orangefs should
     be easy to build, even for Al :-).

     I looked back at the test server build notes in orangefs.txt, just
     in case that's where the trouble really is, and found a couple of
     typos and made a couple of clarifications"

* tag 'for-linus-5.7-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: clarify build steps for test server in orangefs.txt
  orangefs: don't mess with I_DIRTY_TIMES in orangefs_flush
  orangefs: get rid of knob code...

Documentation/filesystems/orangefs.rst

@@ -41,16 +41,6 @@ Documentation
 
 http://www.orangefs.org/documentation/
 
-
-Userspace Filesystem Source
-===========================
-
-http://www.orangefs.org/download
-
-Orangefs versions prior to 2.9.3 would not be compatible with the
-upstream version of the kernel client.
-
-
 Running ORANGEFS On a Single Server
 ===================================
 
@@ -94,6 +84,14 @@ Mount the filesystem::
 
     mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
 
+Userspace Filesystem Source
+===========================
+
+http://www.orangefs.org/download
+
+Orangefs versions prior to 2.9.3 would not be compatible with the
+upstream version of the kernel client.
+
 
 Building ORANGEFS on a Single Server
 ====================================
@@ -107,18 +105,24 @@ default, we will probably be changing the default to LMDB soon.
 
 ::
 
-    ./configure --prefix=/opt/ofs --with-db-backend=lmdb
+    ./configure --prefix=/opt/ofs --with-db-backend=lmdb --disable-usrint
 
     make
 
     make install
 
-Create an orangefs config file::
+Create an orangefs config file by running pvfs2-genconfig and
+specifying a target config file. Pvfs2-genconfig will prompt you
+through. Generally it works fine to take the defaults, but you
+should use your server's hostname, rather than "localhost" when
+it comes to that question::
 
     /opt/ofs/bin/pvfs2-genconfig /etc/pvfs2.conf
 
 Create an /etc/pvfs2tab file::
 
+Localhost is fine for your pvfs2tab file:
+
     echo tcp://localhost:3334/orangefs /pvfsmnt pvfs2 defaults,noauto 0 0 > \
 	/etc/pvfs2tab
 
@@ -132,7 +136,7 @@ Bootstrap the server::
 
 Start the server::
 
-    /opt/osf/sbin/pvfs2-server /etc/pvfs2.conf
+    /opt/ofs/sbin/pvfs2-server /etc/pvfs2.conf
 
 Now the server should be running. Pvfs2-ls is a simple
 test to verify that the server is running::
@@ -142,11 +146,11 @@ test to verify that the server is running::
 If stuff seems to be working, load the kernel module and
 turn on the client core::
 
-    /opt/ofs/sbin/pvfs2-client -p /opt/osf/sbin/pvfs2-client-core
+    /opt/ofs/sbin/pvfs2-client -p /opt/ofs/sbin/pvfs2-client-core
 
 Mount your filesystem::
 
-    mount -t pvfs2 tcp://localhost:3334/orangefs /pvfsmnt
+    mount -t pvfs2 tcp://`hostname`:3334/orangefs /pvfsmnt
 
 
 Running xfstests

fs/orangefs/file.c

@@ -346,23 +346,8 @@ static ssize_t orangefs_file_read_iter(struct kiocb *iocb,
     struct iov_iter *iter)
 {
 	int ret;
-	struct orangefs_read_options *ro;
-
 	orangefs_stats.reads++;
 
-	/*
-	 * Remember how they set "count" in read(2) or pread(2) or whatever -
-	 * users can use count as a knob to control orangefs io size and later
-	 * we can try to help them fill as many pages as possible in readpage.
-	 */
-	if (!iocb->ki_filp->private_data) {
-		iocb->ki_filp->private_data = kmalloc(sizeof *ro, GFP_KERNEL);
-		if (!iocb->ki_filp->private_data)
-			return(ENOMEM);
-		ro = iocb->ki_filp->private_data;
-		ro->blksiz = iter->count;
-	}
-
 	down_read(&file_inode(iocb->ki_filp)->i_rwsem);
 	ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
 	if (ret)
@@ -650,12 +635,6 @@ static int orangefs_lock(struct file *filp, int cmd, struct file_lock *fl)
 	return rc;
 }
 
-static int orangefs_file_open(struct inode * inode, struct file *file)
-{
-	file->private_data = NULL;
-	return generic_file_open(inode, file);
-}
-
 static int orangefs_flush(struct file *file, fl_owner_t id)
 {
 	/*
@@ -666,19 +645,8 @@ static int orangefs_flush(struct file *file, fl_owner_t id)
 	 * on an explicit fsync call.  This duplicates historical OrangeFS
 	 * behavior.
 	 */
-	struct inode *inode = file->f_mapping->host;
 	int r;
 
-	kfree(file->private_data);
-	file->private_data = NULL;
-
-	if (inode->i_state & I_DIRTY_TIME) {
-		spin_lock(&inode->i_lock);
-		inode->i_state &= ~I_DIRTY_TIME;
-		spin_unlock(&inode->i_lock);
-		mark_inode_dirty_sync(inode);
-	}
-
 	r = filemap_write_and_wait_range(file->f_mapping, 0, LLONG_MAX);
 	if (r > 0)
 		return 0;
@@ -694,7 +662,7 @@ const struct file_operations orangefs_file_operations = {
 	.lock		= orangefs_lock,
 	.unlocked_ioctl	= orangefs_ioctl,
 	.mmap		= orangefs_file_mmap,
-	.open		= orangefs_file_open,
+	.open		= generic_file_open,
 	.flush		= orangefs_flush,
 	.release	= orangefs_file_release,
 	.fsync		= orangefs_fsync,

fs/orangefs/inode.c

@@ -259,46 +259,19 @@ static int orangefs_readpage(struct file *file, struct page *page)
 	pgoff_t index; /* which page */
 	struct page *next_page;
 	char *kaddr;
-	struct orangefs_read_options *ro = file->private_data;
 	loff_t read_size;
-	loff_t roundedup;
 	int buffer_index = -1; /* orangefs shared memory slot */
 	int slot_index;   /* index into slot */
 	int remaining;
 
 	/*
-	 * If they set some miniscule size for "count" in read(2)
+	 * Get up to this many bytes from Orangefs at a time and try
-	 * (for example) then let's try to read a page, or the whole file
+	 * to fill them into the page cache at once. Tests with dd made
-	 * if it is smaller than a page. Once "count" goes over a page
+	 * this seem like a reasonable static number, if there was
-	 * then lets round up to the highest page size multiple that is
+	 * interest perhaps this number could be made setable through
-	 * less than or equal to "count" and do that much orangefs IO and
+	 * sysfs...
-	 * try to fill as many pages as we can from it.
-	 *
-	 * "count" should be represented in ro->blksiz.
-	 *
-	 * inode->i_size = file size.
 	 */
-	if (ro) {
+	read_size = 524288;
-		if (ro->blksiz < PAGE_SIZE) {
-			if (inode->i_size < PAGE_SIZE)
-				read_size = inode->i_size;
-			else
-				read_size = PAGE_SIZE;
-		} else {
-			roundedup = ((PAGE_SIZE - 1) & ro->blksiz) ?
-				((ro->blksiz + PAGE_SIZE) & ~(PAGE_SIZE -1)) :
-				ro->blksiz;
-			if (roundedup > inode->i_size)
-				read_size = inode->i_size;
-			else
-				read_size = roundedup;
-
-		}
-	} else {
-		read_size = PAGE_SIZE;
-	}
-	if (!read_size)
-		read_size = PAGE_SIZE;
 
 	if (PageDirty(page))
 		orangefs_launder_page(page);

fs/orangefs/orangefs-kernel.h

@@ -239,10 +239,6 @@ struct orangefs_write_range {
 	kgid_t gid;
 };
 
-struct orangefs_read_options {
-	ssize_t blksiz;
-};
-
 extern struct orangefs_stats orangefs_stats;
 
 /*