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

Pull VFS update from Al Viro:
 "fscache fixes, ESTALE patchset, vmtruncate removal series, assorted
  misc stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (79 commits)
  vfs: make lremovexattr retry once on ESTALE error
  vfs: make removexattr retry once on ESTALE
  vfs: make llistxattr retry once on ESTALE error
  vfs: make listxattr retry once on ESTALE error
  vfs: make lgetxattr retry once on ESTALE
  vfs: make getxattr retry once on an ESTALE error
  vfs: allow lsetxattr() to retry once on ESTALE errors
  vfs: allow setxattr to retry once on ESTALE errors
  vfs: allow utimensat() calls to retry once on an ESTALE error
  vfs: fix user_statfs to retry once on ESTALE errors
  vfs: make fchownat retry once on ESTALE errors
  vfs: make fchmodat retry once on ESTALE errors
  vfs: have chroot retry once on ESTALE error
  vfs: have chdir retry lookup and call once on ESTALE error
  vfs: have faccessat retry once on an ESTALE error
  vfs: have do_sys_truncate retry once on an ESTALE error
  vfs: fix renameat to retry on ESTALE errors
  vfs: make do_unlinkat retry once on ESTALE errors
  vfs: make do_rmdir retry once on ESTALE errors
  vfs: add a flags argument to user_path_parent
  ...

1 files changed, 38 insertions, 8 deletions

diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt
index 7cc6bf2871eb..97e6c0ecc5ef 100644
--- a/Documentation/filesystems/caching/netfs-api.txt
+++ b/Documentation/filesystems/caching/netfs-api.txt
@@ -35,8 +35,9 @@ This document contains the following sections:
         (12) Index and data file update
         (13) Miscellaneous cookie operations
         (14) Cookie unregistration
-        (15) Index and data file invalidation
-        (16) FS-Cache specific page flags.
+        (15) Index invalidation
+        (16) Data file invalidation
+        (17) FS-Cache specific page flags.
 
 
 =============================
@@ -767,13 +768,42 @@ the cookies for "child" indices, objects and pages have been relinquished
 first.
 
 
-================================
-INDEX AND DATA FILE INVALIDATION
-================================
+==================
+INDEX INVALIDATION
+==================
+
+There is no direct way to invalidate an index subtree.  To do this, the caller
+should relinquish and retire the cookie they have, and then acquire a new one.
+
+
+======================
+DATA FILE INVALIDATION
+======================
+
+Sometimes it will be necessary to invalidate an object that contains data.
+Typically this will be necessary when the server tells the netfs of a foreign
+change - at which point the netfs has to throw away all the state it had for an
+inode and reload from the server.
+
+To indicate that a cache object should be invalidated, the following function
+can be called:
+
+        void fscache_invalidate(struct fscache_cookie *cookie);
+
+This can be called with spinlocks held as it defers the work to a thread pool.
+All extant storage, retrieval and attribute change ops at this point are
+cancelled and discarded.  Some future operations will be rejected until the
+cache has had a chance to insert a barrier in the operations queue.  After
+that, operations will be queued again behind the invalidation operation.
+
+The invalidation operation will perform an attribute change operation and an
+auxiliary data update operation as it is very likely these will have changed.
+
+Using the following function, the netfs can wait for the invalidation operation
+to have reached a point at which it can start submitting ordinary operations
+once again:
 
-There is no direct way to invalidate an index subtree or a data file.  To do
-this, the caller should relinquish and retire the cookie they have, and then
-acquire a new one.
+        void fscache_wait_on_invalidate(struct fscache_cookie *cookie);
 
 
 ===========================