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

Pull parallel filesystem directory handling update from Al Viro.

This is the main parallel directory work by Al that makes the vfs layer
able to do lookup and readdir in parallel within a single directory.
That's a big change, since this used to be all protected by the
directory inode mutex.

The inode mutex is replaced by an rwsem, and serialization of lookups of
a single name is done by a "in-progress" dentry marker.

The series begins with xattr cleanups, and then ends with switching
filesystems over to actually doing the readdir in parallel (switching to
the "iterate_shared()" that only takes the read lock).

A more detailed explanation of the process from Al Viro:
 "The xattr work starts with some acl fixes, then switches ->getxattr to
  passing inode and dentry separately.  This is the point where the
  things start to get tricky - that got merged into the very beginning
  of the -rc3-based #work.lookups, to allow untangling the
  security_d_instantiate() mess.  The xattr work itself proceeds to
  switch a lot of filesystems to generic_...xattr(); no complications
  there.

  After that initial xattr work, the series then does the following:

   - untangle security_d_instantiate()

   - convert a bunch of open-coded lookup_one_len_unlocked() to calls of
     that thing; one such place (in overlayfs) actually yields a trivial
     conflict with overlayfs fixes later in the cycle - overlayfs ended
     up switching to a variant of lookup_one_len_unlocked() sans the
     permission checks.  I would've dropped that commit (it gets
     overridden on merge from #ovl-fixes in #for-next; proper resolution
     is to use the variant in mainline fs/overlayfs/super.c), but I
     didn't want to rebase the damn thing - it was fairly late in the
     cycle...

   - some filesystems had managed to depend on lookup/lookup exclusion
     for *fs-internal* data structures in a way that would break if we
     relaxed the VFS exclusion.  Fixing hadn't been hard, fortunately.

   - core of that series - parallel lookup machinery, replacing
     ->i_mutex with rwsem, making lookup_slow() take it only shared.  At
     that point lookups happen in parallel; lookups on the same name
     wait for the in-progress one to be done with that dentry.

     Surprisingly little code, at that - almost all of it is in
     fs/dcache.c, with fs/namei.c changes limited to lookup_slow() -
     making it use the new primitive and actually switching to locking
     shared.

   - parallel readdir stuff - first of all, we provide the exclusion on
     per-struct file basis, same as we do for read() vs lseek() for
     regular files.  That takes care of most of the needed exclusion in
     readdir/readdir; however, these guys are trickier than lookups, so
     I went for switching them one-by-one.  To do that, a new method
     '->iterate_shared()' is added and filesystems are switched to it
     as they are either confirmed to be OK with shared lock on directory
     or fixed to be OK with that.  I hope to kill the original method
     come next cycle (almost all in-tree filesystems are switched
     already), but it's still not quite finished.

   - several filesystems get switched to parallel readdir.  The
     interesting part here is dealing with dcache preseeding by readdir;
     that needs minor adjustment to be safe with directory locked only
     shared.

     Most of the filesystems doing that got switched to in those
     commits.  Important exception: NFS.  Turns out that NFS folks, with
     their, er, insistence on VFS getting the fuck out of the way of the
     Smart Filesystem Code That Knows How And What To Lock(tm) have
     grown the locking of their own.  They had their own homegrown
     rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink
     is the reader there).  Of course, with VFS getting the fuck out of
     the way, as requested, the actual smarts of the smart filesystem
     code etc. had become exposed...

   - do_last/lookup_open/atomic_open cleanups.  As the result, open()
     without O_CREAT locks the directory only shared.  Including the
     ->atomic_open() case.  Backmerge from #for-linus in the middle of
     that - atomic_open() fix got brought in.

   - then comes NFS switch to saner (VFS-based ;-) locking, killing the
     homegrown "lookup and readdir are writers" kinda-sorta rwsem.  All
     exclusion for sillyunlink/lookup is done by the parallel lookups
     mechanism.  Exclusion between sillyunlink and rmdir is a real rwsem
     now - rmdir being the writer.

     Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel
     now.

   - the rest of the series consists of switching a lot of filesystems
     to parallel readdir; in a lot of cases ->llseek() gets simplified
     as well.  One backmerge in there (again, #for-linus - rockridge
     fix)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits)
  ext4: switch to ->iterate_shared()
  hfs: switch to ->iterate_shared()
  hfsplus: switch to ->iterate_shared()
  hostfs: switch to ->iterate_shared()
  hpfs: switch to ->iterate_shared()
  hpfs: handle allocation failures in hpfs_add_pos()
  gfs2: switch to ->iterate_shared()
  f2fs: switch to ->iterate_shared()
  afs: switch to ->iterate_shared()
  befs: switch to ->iterate_shared()
  befs: constify stuff a bit
  isofs: switch to ->iterate_shared()
  get_acorn_filename(): deobfuscate a bit
  btrfs: switch to ->iterate_shared()
  logfs: no need to lock directory in lseek
  switch ecryptfs to ->iterate_shared
  9p: switch to ->iterate_shared()
  fat: switch to ->iterate_shared()
  romfs, squashfs: switch to ->iterate_shared()
  more trivial ->iterate_shared conversions
  ...

11 files changed, 30 insertions, 21 deletions

diff --git a/fs/hfsplus/catalog.c b/fs/hfsplus/catalog.c
index 022974ab6e3c..fb707e8f423a 100644
--- a/fs/hfsplus/catalog.c
+++ b/fs/hfsplus/catalog.c
@@ -374,12 +374,15 @@ int hfsplus_delete_cat(u32 cnid, struct inode *dir, struct qstr *str)
 		hfsplus_free_fork(sb, cnid, &fork, HFSPLUS_TYPE_RSRC);
 	}
 
+	/* we only need to take spinlock for exclusion with ->release() */
+	spin_lock(&HFSPLUS_I(dir)->open_dir_lock);
 	list_for_each(pos, &HFSPLUS_I(dir)->open_dir_list) {
 		struct hfsplus_readdir_data *rd =
 			list_entry(pos, struct hfsplus_readdir_data, list);
 		if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
 			rd->file->f_pos--;
 	}
+	spin_unlock(&HFSPLUS_I(dir)->open_dir_lock);
 
 	err = hfs_brec_remove(&fd);
 	if (err)
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index a4e867e08947..42e128661dc1 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -271,8 +271,14 @@ next:
 		}
 		file->private_data = rd;
 		rd->file = file;
+		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
+		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 	}
+	/*
+	 * Can be done after the list insertion; exclusion with
+	 * hfsplus_delete_cat() is provided by directory lock.
+	 */
 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
 out:
 	kfree(strbuf);
@@ -284,9 +290,9 @@ static int hfsplus_dir_release(struct inode *inode, struct file *file)
 {
 	struct hfsplus_readdir_data *rd = file->private_data;
 	if (rd) {
-		inode_lock(inode);
+		spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 		list_del(&rd->list);
-		inode_unlock(inode);
+		spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 		kfree(rd);
 	}
 	return 0;
@@ -569,7 +575,7 @@ const struct inode_operations hfsplus_dir_inode_operations = {
 const struct file_operations hfsplus_dir_operations = {
 	.fsync		= hfsplus_file_fsync,
 	.read		= generic_read_dir,
-	.iterate	= hfsplus_readdir,
+	.iterate_shared	= hfsplus_readdir,
 	.unlocked_ioctl = hfsplus_ioctl,
 	.llseek		= generic_file_llseek,
 	.release	= hfsplus_dir_release,
diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index f91a1faf819e..fdc3446d934a 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -244,6 +244,7 @@ struct hfsplus_inode_info {
 	u8 userflags;		/* BSD user file flags */
 	u32 subfolders;		/* Subfolder count (HFSX only) */
 	struct list_head open_dir_list;
+	spinlock_t open_dir_lock;
 	loff_t phys_size;
 
 	struct inode vfs_inode;
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index b28f39865c3a..037f738c5871 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -374,6 +374,7 @@ struct inode *hfsplus_new_inode(struct super_block *sb, umode_t mode)
 
 	hip = HFSPLUS_I(inode);
 	INIT_LIST_HEAD(&hip->open_dir_list);
+	spin_lock_init(&hip->open_dir_lock);
 	mutex_init(&hip->extents_lock);
 	atomic_set(&hip->opencnt, 0);
 	hip->extent_state = 0;
diff --git a/fs/hfsplus/posix_acl.c b/fs/hfsplus/posix_acl.c
index afb33eda6d7d..ab7ea2506b4d 100644
--- a/fs/hfsplus/posix_acl.c
+++ b/fs/hfsplus/posix_acl.c
@@ -48,9 +48,6 @@ struct posix_acl *hfsplus_get_posix_acl(struct inode *inode, int type)
 
 	hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
 
-	if (!IS_ERR(acl))
-		set_cached_acl(inode, type, acl);
-
 	return acl;
 }
 
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index c35911362ff9..755bf30ba1ce 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -67,6 +67,7 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
 		return inode;
 
 	INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
+	spin_lock_init(&HFSPLUS_I(inode)->open_dir_lock);
 	mutex_init(&HFSPLUS_I(inode)->extents_lock);
 	HFSPLUS_I(inode)->flags = 0;
 	HFSPLUS_I(inode)->extent_state = 0;
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index 70e445ff0cff..4f118d282a7a 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -579,7 +579,7 @@ failed_getxattr_init:
 	return res;
 }
 
-ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
+ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
 			 void *value, size_t size,
 			 const char *prefix, size_t prefixlen)
 {
@@ -594,7 +594,7 @@ ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
 	strcpy(xattr_name, prefix);
 	strcpy(xattr_name + prefixlen, name);
 
-	res = __hfsplus_getxattr(d_inode(dentry), xattr_name, value, size);
+	res = __hfsplus_getxattr(inode, xattr_name, value, size);
 	kfree(xattr_name);
 	return res;
 
@@ -844,8 +844,8 @@ end_removexattr:
 }
 
 static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
-				struct dentry *dentry, const char *name,
-				void *buffer, size_t size)
+				struct dentry *unused, struct inode *inode,
+				const char *name, void *buffer, size_t size)
 {
 	/*
 	 * Don't allow retrieving properly prefixed attributes
@@ -860,7 +860,7 @@ static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 	 * creates), so we pass the name through unmodified (after
 	 * ensuring it doesn't conflict with another namespace).
 	 */
-	return __hfsplus_getxattr(d_inode(dentry), name, buffer, size);
+	return __hfsplus_getxattr(inode, name, buffer, size);
 }
 
 static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
diff --git a/fs/hfsplus/xattr.h b/fs/hfsplus/xattr.h
index f9b0955b3d28..d04ba6f58df2 100644
--- a/fs/hfsplus/xattr.h
+++ b/fs/hfsplus/xattr.h
@@ -28,7 +28,7 @@ int hfsplus_setxattr(struct dentry *dentry, const char *name,
 ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
 			   void *value, size_t size);
 
-ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
+ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
 			 void *value, size_t size,
 			 const char *prefix, size_t prefixlen);
 
diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
index 72a68a3a0c99..ae2ca8c2e335 100644
--- a/fs/hfsplus/xattr_security.c
+++ b/fs/hfsplus/xattr_security.c
@@ -14,10 +14,10 @@
 #include "acl.h"
 
 static int hfsplus_security_getxattr(const struct xattr_handler *handler,
-				     struct dentry *dentry, const char *name,
-				     void *buffer, size_t size)
+				     struct dentry *unused, struct inode *inode,
+				     const char *name, void *buffer, size_t size)
 {
-	return hfsplus_getxattr(dentry, name, buffer, size,
+	return hfsplus_getxattr(inode, name, buffer, size,
 				XATTR_SECURITY_PREFIX,
 				XATTR_SECURITY_PREFIX_LEN);
 }
diff --git a/fs/hfsplus/xattr_trusted.c b/fs/hfsplus/xattr_trusted.c
index 95a7704c7abb..eae2947060aa 100644
--- a/fs/hfsplus/xattr_trusted.c
+++ b/fs/hfsplus/xattr_trusted.c
@@ -12,10 +12,10 @@
 #include "xattr.h"
 
 static int hfsplus_trusted_getxattr(const struct xattr_handler *handler,
-				    struct dentry *dentry, const char *name,
-				    void *buffer, size_t size)
+				    struct dentry *unused, struct inode *inode,
+				    const char *name, void *buffer, size_t size)
 {
-	return hfsplus_getxattr(dentry, name, buffer, size,
+	return hfsplus_getxattr(inode, name, buffer, size,
 				XATTR_TRUSTED_PREFIX,
 				XATTR_TRUSTED_PREFIX_LEN);
 }
diff --git a/fs/hfsplus/xattr_user.c b/fs/hfsplus/xattr_user.c
index 6fc269baf959..3c9eec3e4c7b 100644
--- a/fs/hfsplus/xattr_user.c
+++ b/fs/hfsplus/xattr_user.c
@@ -12,11 +12,11 @@
 #include "xattr.h"
 
 static int hfsplus_user_getxattr(const struct xattr_handler *handler,
-				 struct dentry *dentry, const char *name,
-				 void *buffer, size_t size)
+				 struct dentry *unused, struct inode *inode,
+				 const char *name, void *buffer, size_t size)
 {
 
-	return hfsplus_getxattr(dentry, name, buffer, size,
+	return hfsplus_getxattr(inode, name, buffer, size,
 				XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
 }