Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull VFS changes from Al Viro:
 "First pile out of several (there _definitely_ will be more).  Stuff in
  this one:

   - unification of d_splice_alias()/d_materialize_unique()

   - iov_iter rewrite

   - killing a bunch of ->f_path.dentry users (and f_dentry macro).

     Getting that completed will make life much simpler for
     unionmount/overlayfs, since then we'll be able to limit the places
     sensitive to file _dentry_ to reasonably few.  Which allows to have
     file_inode(file) pointing to inode in a covered layer, with dentry
     pointing to (negative) dentry in union one.

     Still not complete, but much closer now.

   - crapectomy in lustre (dead code removal, mostly)

   - "let's make seq_printf return nothing" preparations

   - assorted cleanups and fixes

  There _definitely_ will be more piles"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  copy_from_iter_nocache()
  new helper: iov_iter_kvec()
  csum_and_copy_..._iter()
  iov_iter.c: handle ITER_KVEC directly
  iov_iter.c: convert copy_to_iter() to iterate_and_advance
  iov_iter.c: convert copy_from_iter() to iterate_and_advance
  iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
  iov_iter.c: convert iov_iter_zero() to iterate_and_advance
  iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds
  iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds
  iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
  iov_iter.c: iterate_and_advance
  iov_iter.c: macros for iterating over iov_iter
  kill f_dentry macro
  dcache: fix kmemcheck warning in switch_names
  new helper: audit_file()
  nfsd_vfs_write(): use file_inode()
  ncpfs: use file_inode()
  kill f_dentry uses
  lockd: get rid of ->f_path.dentry->d_sb
  ...

5 files changed, 28 insertions, 29 deletions

diff --git a/Documentation/filesystems/debugfs.txt b/Documentation/filesystems/debugfs.txt
index 3a863f692728..88ab81c79109 100644
--- a/Documentation/filesystems/debugfs.txt
+++ b/Documentation/filesystems/debugfs.txt
@@ -140,7 +140,7 @@ file.
                                      struct dentry *parent,
                                      struct debugfs_regset32 *regset);
 
-    int debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
+    void debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
                          int nregs, void __iomem *base, char *prefix);
 
 The "base" argument may be 0, but you may want to build the reg32 array
diff --git a/Documentation/filesystems/nfs/Exporting b/Documentation/filesystems/nfs/Exporting
index c8f036a9b13f..520a4becb75c 100644
--- a/Documentation/filesystems/nfs/Exporting
+++ b/Documentation/filesystems/nfs/Exporting
@@ -72,24 +72,11 @@ c/ Helper routines to allocate anonymous dentries, and to help attach
         DCACHE_DISCONNECTED) dentry is allocated and attached.
       In the case of a directory, care is taken that only one dentry
       can ever be attached.
-    d_splice_alias(inode, dentry) or d_materialise_unique(dentry, inode)
-      will introduce a new dentry into the tree; either the passed-in
-      dentry or a preexisting alias for the given inode (such as an
-      anonymous one created by d_obtain_alias), if appropriate.  The two
-      functions differ in their handling of directories with preexisting
-      aliases:
-        d_splice_alias will use any existing IS_ROOT dentry, but it will
-          return -EIO rather than try to move a dentry with a different
-          parent.  This is appropriate for local filesystems, which
-          should never see such an alias unless the filesystem is
-          corrupted somehow (for example, if two on-disk directory
-          entries refer to the same directory.)
-        d_materialise_unique will attempt to move any dentry.  This is
-          appropriate for distributed filesystems, where finding a
-          directory other than where we last cached it may be a normal
-          consequence of concurrent operations on other hosts.
-      Both functions return NULL when the passed-in dentry is used,
-      following the calling convention of ->lookup.
+    d_splice_alias(inode, dentry) will introduce a new dentry into the tree;
+      either the passed-in dentry or a preexisting alias for the given inode
+      (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/porting b/Documentation/filesystems/porting
index 0f3a1390bf00..fa2db081505e 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -463,3 +463,11 @@ in your dentry operations instead.
         of the in-tree instances did).  inode_hash_lock is still held,
         of course, so they are still serialized wrt removal from inode hash,
         as well as wrt set() callback of iget5_locked().
+--
+[mandatory]
+        d_materialise_unique() is gone; d_splice_alias() does everything you
+        need now.  Remember that they have opposite orders of arguments ;-/
+--
+[mandatory]
+        f_dentry is gone; use f_path.dentry, or, better yet, see if you can avoid
+        it entirely.
diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt
index 8ea3e90ace07..b797ed38de46 100644
--- a/Documentation/filesystems/seq_file.txt
+++ b/Documentation/filesystems/seq_file.txt
@@ -180,23 +180,19 @@ output must be passed to the seq_file code. Some utility functions have
 been defined which make this task easy.
 
 Most code will simply use seq_printf(), which works pretty much like
-printk(), but which requires the seq_file pointer as an argument. It is
-common to ignore the return value from seq_printf(), but a function
-producing complicated output may want to check that value and quit if
-something non-zero is returned; an error return means that the seq_file
-buffer has been filled and further output will be discarded.
+printk(), but which requires the seq_file pointer as an argument.
 
 For straight character output, the following functions may be used:
 
-        int seq_putc(struct seq_file *m, char c);
-        int seq_puts(struct seq_file *m, const char *s);
-        int seq_escape(struct seq_file *m, const char *s, const char *esc);
+        seq_putc(struct seq_file *m, char c);
+        seq_puts(struct seq_file *m, const char *s);
+        seq_escape(struct seq_file *m, const char *s, const char *esc);
 
 The first two output a single character and a string, just like one would
 expect. seq_escape() is like seq_puts(), except that any character in s
 which is in the string esc will be represented in octal form in the output.
 
-There is also a pair of functions for printing filenames:
+There are also a pair of functions for printing filenames:
 
         int seq_path(struct seq_file *m, struct path *path, char *esc);
         int seq_path_root(struct seq_file *m, struct path *path,
@@ -209,6 +205,14 @@ root is desired, it can be used with seq_path_root().  Note that, if it
 turns out that path cannot be reached from root, the value of root will be
 changed in seq_file_root() to a root which *does* work.
 
+A function producing complicated output may want to check
+        bool seq_has_overflowed(struct seq_file *m);
+and avoid further seq_<output> calls if true is returned.
+
+A true return from seq_has_overflowed means that the seq_file buffer will
+be discarded and the seq_show function will attempt to allocate a larger
+buffer and retry printing.
+
 
 Making it all work
 
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 20bf204426ca..43ce0507ee25 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -835,7 +835,7 @@ struct file_operations {
         ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int);
         int (*setlease)(struct file *, long arg, struct file_lock **, void **);
         long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len);
-        int (*show_fdinfo)(struct seq_file *m, struct file *f);
+        void (*show_fdinfo)(struct seq_file *m, struct file *f);
 };
 
 Again, all methods are called without any locks being held, unless