[PATCH] ufs: one way to access super block

Super block of UFS usually has size >512, because of fragment size may be 512,
this cause some problems.

Currently, there are two methods to work with ufs super block:

1) split structure which describes ufs super blocks into structures with
   size <=512

2) use one structure which describes ufs super block, and hope that array
   of "buffer_head" which holds "super block", has such construction:

	bh[n]->b_data + bh[n]->b_size == bh[n + 1]->b_data

The second variant may cause some problems in the future, and usage of two
variants cause unnecessary code duplication.

This patch remove the second variant.  Also patch contains some CodingStyle
fixes.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 52 insertions, 9 deletions

diff --git a/include/linux/ufs_fs.h b/include/linux/ufs_fs.h
index 28b31591f688..87b0a658bec8 100644
--- a/include/linux/ufs_fs.h
+++ b/include/linux/ufs_fs.h
@@ -351,8 +351,12 @@ struct ufs2_csum_total {
 	__fs64   cs_spare[3];	/* future expansion */
 };
 
+#if 0
 /*
  * This is the actual superblock, as it is laid out on the disk.
+ * Do NOT use this structure, because of sizeof(ufs_super_block) > 512 and
+ * it may occupy several blocks, use
+ * struct ufs_super_block_(first,second,third) instead.
  */
 struct ufs_super_block {
 	__fs32	fs_link;	/* UNUSED */
@@ -498,6 +502,7 @@ struct ufs_super_block {
 	__fs32	fs_magic;		/* magic number */
 	__u8	fs_space[1];		/* list of blocks for each rotation */
 };
+#endif/*struct ufs_super_block*/
 
 /*
  * Preference for optimization.
@@ -837,16 +842,54 @@ struct ufs_super_block_first {
 };
 
 struct ufs_super_block_second {
-	__s8	fs_fsmnt[212];
-	__fs32	fs_cgrotor;
-	__fs32	fs_csp[UFS_MAXCSBUFS];
-	__fs32	fs_maxcluster;
-	__fs32	fs_cpc;
-	__fs16	fs_opostbl[82];
-};	
+	union {
+		struct {
+			__s8	fs_fsmnt[212];
+			__fs32	fs_cgrotor;
+			__fs32	fs_csp[UFS_MAXCSBUFS];
+			__fs32	fs_maxcluster;
+			__fs32	fs_cpc;
+			__fs16	fs_opostbl[82];
+		} fs_u1;
+		struct {
+			__s8  fs_fsmnt[UFS2_MAXMNTLEN - UFS_MAXMNTLEN + 212];
+			__u8   fs_volname[UFS2_MAXVOLLEN];
+			__fs64  fs_swuid;
+			__fs32  fs_pad;
+			__fs32   fs_cgrotor;
+			__fs32   fs_ocsp[UFS2_NOCSPTRS];
+			__fs32   fs_contigdirs;
+			__fs32   fs_csp;
+			__fs32   fs_maxcluster;
+			__fs32   fs_active;
+			__fs32   fs_old_cpc;
+			__fs32   fs_maxbsize;
+			__fs64   fs_sparecon64[17];
+			__fs64   fs_sblockloc;
+			__fs64	cs_ndir;
+			__fs64	cs_nbfree;
+		} fs_u2;
+	} fs_un;
+};
 
 struct ufs_super_block_third {
-	__fs16	fs_opostbl[46];
+	union {
+		struct {
+			__fs16	fs_opostbl[46];
+		} fs_u1;
+		struct {
+			__fs64	cs_nifree;	/* number of free inodes */
+			__fs64	cs_nffree;	/* number of free frags */
+			__fs64   cs_numclusters;	/* number of free clusters */
+			__fs64   cs_spare[3];	/* future expansion */
+			struct  ufs_timeval    fs_time;		/* last time written */
+			__fs64    fs_size;		/* number of blocks in fs */
+			__fs64    fs_dsize;	/* number of data blocks in fs */
+			__fs64   fs_csaddr;	/* blk addr of cyl grp summary area */
+			__fs64    fs_pendingblocks;/* blocks in process of being freed */
+			__fs32    fs_pendinginodes;/*inodes in process of being freed */
+		} fs_u2;
+	} fs_un1;
 	union {
 		struct {
 			__fs32	fs_sparecon[53];/* reserved for future constants */
@@ -874,7 +917,7 @@ struct ufs_super_block_third {
 			__fs32	fs_qfmask[2];	/* ~usb_fmask */
 			__fs32	fs_state;	/* file system state time stamp */
 		} fs_44;
-	} fs_u2;
+	} fs_un2;
 	__fs32	fs_postblformat;
 	__fs32	fs_nrpos;
 	__fs32	fs_postbloff;