6 files changed, 59 insertions, 17 deletions
diff --git a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt
index 55755395d3dc..81c0becab225 100644
--- a/Documentation/filesystems/ext2.txt
+++ b/Documentation/filesystems/ext2.txt
@@ -49,12 +49,10 @@ sb=n				Use alternate superblock at this location.
 
 user_xattr			Enable "user." POSIX Extended Attributes
 				(requires CONFIG_EXT2_FS_XATTR).
-				See also http://acl.bestbits.at
 nouser_xattr			Don't support "user." extended attributes.
 
 acl				Enable POSIX Access Control Lists support
 				(requires CONFIG_EXT2_FS_POSIX_ACL).
-				See also http://acl.bestbits.at
 noacl				Don't support POSIX ACLs.
 
 nobh				Do not attach buffer_heads to file pagecache.
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 75236c0c2ac2..8cd63e16f171 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -202,15 +202,14 @@ inode_readahead_blks=n	This tuning parameter controls the maximum
 			the buffer cache.  The default value is 32 blocks.
 
 nouser_xattr		Disables Extended User Attributes.  See the
-			attr(5) manual page and http://acl.bestbits.at/
-			for more information about extended attributes.
+			attr(5) manual page for more information about
+			extended attributes.
 
 noacl			This option disables POSIX Access Control List
 			support. If ACL support is enabled in the kernel
 			configuration (CONFIG_EXT4_FS_POSIX_ACL), ACL is
 			enabled by default on mount. See the acl(5) manual
-			page and http://acl.bestbits.at/ for more information
-			about acl.
+			page for more information about acl.
 
 bsddf		(*)	Make 'df' act like BSD.
 minixdf			Make 'df' act like Minix.
diff --git a/Documentation/filesystems/nfs/Exporting b/Documentation/filesystems/nfs/Exporting
index 520a4becb75c..63889149f532 100644
--- a/Documentation/filesystems/nfs/Exporting
+++ b/Documentation/filesystems/nfs/Exporting
@@ -56,13 +56,25 @@ a/ A dentry flag DCACHE_DISCONNECTED which is set on
    any dentry that might not be part of the proper prefix.
    This is set when anonymous dentries are created, and cleared when a
    dentry is noticed to be a child of a dentry which is in the proper
-   prefix. 
-
-b/ A per-superblock list "s_anon" of dentries which are the roots of
-   subtrees that are not in the proper prefix.  These dentries, as
-   well as the proper prefix, need to be released at unmount time.  As
-   these dentries will not be hashed, they are linked together on the
-   d_hash list_head.
+   prefix.  If the refcount on a dentry with this flag set
+   becomes zero, the dentry is immediately discarded, rather than being
+   kept in the dcache.  If a dentry that is not already in the dcache
+   is repeatedly accessed by filehandle (as NFSD might do), an new dentry
+   will be a allocated for each access, and discarded at the end of
+   the access.
+
+   Note that such a dentry can acquire children, name, ancestors, etc.
+   without losing DCACHE_DISCONNECTED - that flag is only cleared when
+   subtree is successfully reconnected to root.  Until then dentries
+   in such subtree are retained only as long as there are references;
+   refcount reaching zero means immediate eviction, same as for unhashed
+   dentries.  That guarantees that we won't need to hunt them down upon
+   umount.
+
+b/ A primitive for creation of secondary roots - d_obtain_root(inode).
+   Those do _not_ bear DCACHE_DISCONNECTED.  They are placed on the
+   per-superblock list (->s_roots), so they can be located at umount
+   time for eviction purposes.
 
 c/ Helper routines to allocate anonymous dentries, and to help attach
    loose directory dentries at lookup time. They are:
@@ -77,7 +89,6 @@ c/ Helper routines to allocate anonymous dentries, and to help attach
       (such as an anonymous one created by d_obtain_alias), if appropriate.
       It returns NULL when the passed-in dentry is used, following the calling
       convention of ->lookup.
-
  
 Filesystem Issues
 -----------------
diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt
index c0727dc36271..f2f3f8592a6f 100644
--- a/Documentation/filesystems/nilfs2.txt
+++ b/Documentation/filesystems/nilfs2.txt
@@ -25,8 +25,8 @@ available from the following download page.  At least "mkfs.nilfs2",
 cleaner or garbage collector) are required.  Details on the tools are
 described in the man pages included in the package.
 
-Project web page:    http://nilfs.sourceforge.net/
-Download page:       http://nilfs.sourceforge.net/en/download.html
+Project web page:    https://nilfs.sourceforge.io/
+Download page:       https://nilfs.sourceforge.io/en/download.html
 List info:           http://vger.kernel.org/vger-lists.html#linux-nilfs
 
 Caveats
diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt
index 8caa60734647..e6a5f4912b6d 100644
--- a/Documentation/filesystems/overlayfs.txt
+++ b/Documentation/filesystems/overlayfs.txt
@@ -156,6 +156,40 @@ handle it in two different ways:
    root of the overlay.  Finally the directory is moved to the new
    location.
 
+There are several ways to tune the "redirect_dir" feature.
+
+Kernel config options:
+
+- OVERLAY_FS_REDIRECT_DIR:
+    If this is enabled, then redirect_dir is turned on by  default.
+- OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW:
+    If this is enabled, then redirects are always followed by default. Enabling
+    this results in a less secure configuration.  Enable this option only when
+    worried about backward compatibility with kernels that have the redirect_dir
+    feature and follow redirects even if turned off.
+
+Module options (can also be changed through /sys/module/overlay/parameters/*):
+
+- "redirect_dir=BOOL":
+    See OVERLAY_FS_REDIRECT_DIR kernel config option above.
+- "redirect_always_follow=BOOL":
+    See OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW kernel config option above.
+- "redirect_max=NUM":
+    The maximum number of bytes in an absolute redirect (default is 256).
+
+Mount options:
+
+- "redirect_dir=on":
+    Redirects are enabled.
+- "redirect_dir=follow":
+    Redirects are not created, but followed.
+- "redirect_dir=off":
+    Redirects are not created and only followed if "redirect_always_follow"
+    feature is enabled in the kernel/module config.
+- "redirect_dir=nofollow":
+    Redirects are not created and not followed (equivalent to "redirect_dir=off"
+    if "redirect_always_follow" feature is not enabled).
+
 Non-directories
 ---------------
 
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index cf51360e3a9f..91031298beb1 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -344,4 +344,4 @@ the following:
 	   characters in the final slot are set to Unicode 0xFFFF.
 
 Finally, note that the extended name is stored in Unicode.  Each Unicode
-character takes two bytes.
+character takes either two or four bytes, UTF-16LE encoded.