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

Pull large btrfs update from Chris Mason:
 "This pull request is very large, and the two main features in here
  have been under testing/devel for quite a while.

  We have subvolume quotas from the strato developers.  This enables
  full tracking of how many blocks are allocated to each subvolume (and
  all snapshots) and you can set limits on a per-subvolume basis.  You
  can also create quota groups and toss multiple subvolumes into a big
  group.  It's everything you need to be a web hosting company and give
  each user their own subvolume.

  The userland side of the quotas is being refreshed, they'll send out
  details on where to grab it soon.

  Next is the kernel side of btrfs send/receive from Alexander Block.
  This leverages the same infrastructure as the quota code to figure out
  relationships between blocks and their owners.  It can then compute
  the difference between two snapshots and sends the diffs in a neutral
  format into userland.

  The basic model:

        create a snapshot
        send that snapshot as the initial backup
        make changes
        create a second snapshot
        send the incremental as a backup
        delete the first snapshot
        (use the second snapshot for the next incremental)

  The receive portion is all in userland, and in the 'next' branch of my
  btrfs-progs repo.

  There's still some work to do in terms of optimizing the send side
  from kernel to userland.  The really important part is figuring out
  how two snapshots are different, and this is where we are
  concentrating right now.  The initial send of a dataset is a little
  slower than tar, but the incremental sends are dramatically faster
  than what rsync can do.

  On top of all of that, we have a nice queue of fixes, cleanups and
  optimizations."

Fix up trivial modify/del conflict in fs/btrfs/ioctl.c

Also fix up semantic conflict in fs/btrfs/send.c: the interface to
dentry_open() changed in commit 765927b2d508 ("switch dentry_open() to
struct path, make it grab references itself"), and since it now grabs
whatever references it needs, we should no longer do the mntget() on the
mnt (and we need to dput() the dentry reference we took).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (65 commits)
  Btrfs: uninit variable fixes in send/receive
  Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive
  Btrfs: add btrfs_compare_trees function
  Btrfs: introduce subvol uuids and times
  Btrfs: make iref_to_path non static
  Btrfs: add a barrier before a waitqueue_active check
  Btrfs: call the ordered free operation without any locks held
  Btrfs: Check INCOMPAT flags on remount and add helper function
  Btrfs: add helper for tree enumeration
  btrfs: allow cross-subvolume file clone
  Btrfs: improve multi-thread buffer read
  Btrfs: make btrfs's allocation smoothly with preallocation
  Btrfs: lock the transition from dirty to writeback for an eb
  Btrfs: fix potential race in extent buffer freeing
  Btrfs: don't return true in releasepage unless we actually freed the eb
  Btrfs: suppress printk() if all device I/O stats are zero
  Btrfs: remove unwanted printk() for btrfs device I/O stats
  Btrfs: rewrite BTRFS_SETGET_FUNCS
  Btrfs: zero unused bytes in inode item
  Btrfs: kill free_space pointer from inode structure
  ...

Conflicts:
	fs/btrfs/ioctl.c

1 files changed, 99 insertions, 97 deletions

diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index c6ffa581241..b976597b072 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -17,15 +17,27 @@
  */
 
 #include <linux/highmem.h>
+#include <asm/unaligned.h>
 
-/* this is some deeply nasty code.  ctree.h has a different
- * definition for this BTRFS_SETGET_FUNCS macro, behind a #ifndef
+#include "ctree.h"
+
+static inline u8 get_unaligned_le8(const void *p)
+{
+       return *(u8 *)p;
+}
+
+static inline void put_unaligned_le8(u8 val, void *p)
+{
+       *(u8 *)p = val;
+}
+
+/*
+ * this is some deeply nasty code.
  *
  * The end result is that anyone who #includes ctree.h gets a
- * declaration for the btrfs_set_foo functions and btrfs_foo functions
- *
- * This file declares the macros and then #includes ctree.h, which results
- * in cpp creating the function here based on the template below.
+ * declaration for the btrfs_set_foo functions and btrfs_foo functions,
+ * which are wappers of btrfs_set_token_#bits functions and
+ * btrfs_get_token_#bits functions, which are defined in this file.
  *
  * These setget functions do all the extent_buffer related mapping
  * required to efficiently read and write specific fields in the extent
@@ -33,103 +45,93 @@
  * an unsigned long offset into the extent buffer which has been
  * cast to a specific type.  This gives us all the gcc type checking.
  *
- * The extent buffer api is used to do all the kmapping and page
- * spanning work required to get extent buffers in highmem and have
- * a metadata blocksize different from the page size.
- *
- * The macro starts with a simple function prototype declaration so that
- * sparse won't complain about it being static.
+ * The extent buffer api is used to do the page spanning work required to
+ * have a metadata blocksize different from the page size.
  */
 
-#define BTRFS_SETGET_FUNCS(name, type, member, bits)			\
-u##bits btrfs_##name(struct extent_buffer *eb, type *s);		\
-void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);	\
-void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token);	\
-u##bits btrfs_token_##name(struct extent_buffer *eb,				\
-			   type *s, struct btrfs_map_token *token)	\
+#define DEFINE_BTRFS_SETGET_BITS(bits)					\
+u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr,	\
+			       unsigned long off,			\
+			       struct btrfs_map_token *token)		\
 {									\
-	unsigned long part_offset = (unsigned long)s;			\
-	unsigned long offset = part_offset + offsetof(type, member);	\
-	type *p;							\
-	int err;						\
-	char *kaddr;						\
-	unsigned long map_start;				\
-	unsigned long map_len;					\
-	unsigned long mem_len = sizeof(((type *)0)->member);	\
-	u##bits res;						\
-	if (token && token->kaddr && token->offset <= offset &&	\
-	    token->eb == eb &&					\
-	   (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \
-		kaddr = token->kaddr;				\
-		p = (type *)(kaddr + part_offset - token->offset);  \
-		res = le##bits##_to_cpu(p->member);		\
-		return res;					\
-	}							\
-	err = map_private_extent_buffer(eb, offset,		\
-			mem_len,				\
-			&kaddr, &map_start, &map_len);		\
-	if (err) {						\
-		__le##bits leres;				\
-		read_eb_member(eb, s, type, member, &leres);	\
-		return le##bits##_to_cpu(leres);		\
-	}							\
-	p = (type *)(kaddr + part_offset - map_start);		\
-	res = le##bits##_to_cpu(p->member);			\
-	if (token) {						\
-		token->kaddr = kaddr;				\
-		token->offset = map_start;			\
-		token->eb = eb;					\
-	}							\
-	return res;						\
+	unsigned long part_offset = (unsigned long)ptr;			\
+	unsigned long offset = part_offset + off;			\
+	void *p;							\
+	int err;							\
+	char *kaddr;							\
+	unsigned long map_start;					\
+	unsigned long map_len;						\
+	int size = sizeof(u##bits);					\
+	u##bits res;							\
+									\
+	if (token && token->kaddr && token->offset <= offset &&		\
+	    token->eb == eb &&						\
+	   (token->offset + PAGE_CACHE_SIZE >= offset + size)) {	\
+		kaddr = token->kaddr;					\
+		p = kaddr + part_offset - token->offset;		\
+		res = get_unaligned_le##bits(p + off);			\
+		return res;						\
+	}								\
+	err = map_private_extent_buffer(eb, offset, size,		\
+					&kaddr, &map_start, &map_len);	\
+	if (err) {							\
+		__le##bits leres;					\
+									\
+		read_extent_buffer(eb, &leres, offset, size);		\
+		return le##bits##_to_cpu(leres);			\
+	}								\
+	p = kaddr + part_offset - map_start;				\
+	res = get_unaligned_le##bits(p + off);				\
+	if (token) {							\
+		token->kaddr = kaddr;					\
+		token->offset = map_start;				\
+		token->eb = eb;						\
+	}								\
+	return res;							\
 }									\
-void btrfs_set_token_##name(struct extent_buffer *eb,				\
-			    type *s, u##bits val, struct btrfs_map_token *token)		\
+void btrfs_set_token_##bits(struct extent_buffer *eb,			\
+			    void *ptr, unsigned long off, u##bits val,	\
+			    struct btrfs_map_token *token)		\
 {									\
-	unsigned long part_offset = (unsigned long)s;			\
-	unsigned long offset = part_offset + offsetof(type, member);	\
-	type *p;							\
-	int err;						\
-	char *kaddr;						\
-	unsigned long map_start;				\
-	unsigned long map_len;					\
-	unsigned long mem_len = sizeof(((type *)0)->member);	\
-	if (token && token->kaddr && token->offset <= offset &&	\
-	    token->eb == eb &&					\
-	   (token->offset + PAGE_CACHE_SIZE >= offset + mem_len)) { \
-		kaddr = token->kaddr;				\
-		p = (type *)(kaddr + part_offset - token->offset);  \
-		p->member = cpu_to_le##bits(val);		\
-		return;						\
-	}							\
-	err = map_private_extent_buffer(eb, offset,		\
-			mem_len,				\
-			&kaddr, &map_start, &map_len);		\
-	if (err) {						\
-		__le##bits val2;				\
-		val2 = cpu_to_le##bits(val);			\
-		write_eb_member(eb, s, type, member, &val2);	\
-		return;						\
-	}							\
-	p = (type *)(kaddr + part_offset - map_start);		\
-	p->member = cpu_to_le##bits(val);			\
-	if (token) {						\
-		token->kaddr = kaddr;				\
-		token->offset = map_start;			\
-		token->eb = eb;					\
-	}							\
-}								\
-void btrfs_set_##name(struct extent_buffer *eb,			\
-		      type *s, u##bits val)			\
-{								\
-	btrfs_set_token_##name(eb, s, val, NULL);		\
-}								\
-u##bits btrfs_##name(struct extent_buffer *eb,			\
-		      type *s)					\
-{								\
-	return btrfs_token_##name(eb, s, NULL);			\
-}								\
+	unsigned long part_offset = (unsigned long)ptr;			\
+	unsigned long offset = part_offset + off;			\
+	void *p;							\
+	int err;							\
+	char *kaddr;							\
+	unsigned long map_start;					\
+	unsigned long map_len;						\
+	int size = sizeof(u##bits);					\
+									\
+	if (token && token->kaddr && token->offset <= offset &&		\
+	    token->eb == eb &&						\
+	   (token->offset + PAGE_CACHE_SIZE >= offset + size)) {	\
+		kaddr = token->kaddr;					\
+		p = kaddr + part_offset - token->offset;		\
+		put_unaligned_le##bits(val, p + off);			\
+		return;							\
+	}								\
+	err = map_private_extent_buffer(eb, offset, size,		\
+			&kaddr, &map_start, &map_len);			\
+	if (err) {							\
+		__le##bits val2;					\
+									\
+		val2 = cpu_to_le##bits(val);				\
+		write_extent_buffer(eb, &val2, offset, size);		\
+		return;							\
+	}								\
+	p = kaddr + part_offset - map_start;				\
+	put_unaligned_le##bits(val, p + off);				\
+	if (token) {							\
+		token->kaddr = kaddr;					\
+		token->offset = map_start;				\
+		token->eb = eb;						\
+	}								\
+}
 
-#include "ctree.h"
+DEFINE_BTRFS_SETGET_BITS(8)
+DEFINE_BTRFS_SETGET_BITS(16)
+DEFINE_BTRFS_SETGET_BITS(32)
+DEFINE_BTRFS_SETGET_BITS(64)
 
 void btrfs_node_key(struct extent_buffer *eb,
 		    struct btrfs_disk_key *disk_key, int nr)