ufs: fix s_size/s_dsize users

For UFS2 we need 64bit variants; we even store them in uspi, but
use 32bit ones instead.  One wrinkle is in handling of reserved
space - recalculating it every time had been stupid all along, but
now it would become really ugly.  Just calculate it once...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ufs/balloc.c

@@ -400,7 +400,7 @@ u64 ufs_new_fragments(struct inode *inode, void *p, u64 fragment,
 	/*
 	 * There is not enough space for user on the device
 	 */
-	if (unlikely(ufs_freespace(uspi, uspi->s_minfree) <= 0)) {
+	if (unlikely(ufs_freefrags(uspi) <= uspi->s_root_blocks)) {
 		if (!capable(CAP_SYS_RESOURCE)) {
 			mutex_unlock(&UFS_SB(sb)->s_lock);
 			UFSD("EXIT (FAILED)\n");

fs/ufs/super.c

@@ -1159,8 +1159,8 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 	uspi->s_cgmask = fs32_to_cpu(sb, usb1->fs_cgmask);
 
 	if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2) {
-		uspi->s_u2_size  = fs64_to_cpu(sb, usb3->fs_un1.fs_u2.fs_size);
-		uspi->s_u2_dsize = fs64_to_cpu(sb, usb3->fs_un1.fs_u2.fs_dsize);
+		uspi->s_size  = fs64_to_cpu(sb, usb3->fs_un1.fs_u2.fs_size);
+		uspi->s_dsize = fs64_to_cpu(sb, usb3->fs_un1.fs_u2.fs_dsize);
 	} else {
 		uspi->s_size  =  fs32_to_cpu(sb, usb1->fs_size);
 		uspi->s_dsize =  fs32_to_cpu(sb, usb1->fs_dsize);
@@ -1209,6 +1209,9 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 	uspi->s_postbloff = fs32_to_cpu(sb, usb3->fs_postbloff);
 	uspi->s_rotbloff = fs32_to_cpu(sb, usb3->fs_rotbloff);
 
+	uspi->s_root_blocks = mul_u64_u32_div(uspi->s_dsize,
+					      uspi->s_minfree, 100);
+
 	/*
 	 * Compute another frequently used values
 	 */
@@ -1398,19 +1401,17 @@ static int ufs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	mutex_lock(&UFS_SB(sb)->s_lock);
 	usb3 = ubh_get_usb_third(uspi);
 	
-	if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2) {
+	if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
 		buf->f_type = UFS2_MAGIC;
-		buf->f_blocks = fs64_to_cpu(sb, usb3->fs_un1.fs_u2.fs_dsize);
-	} else {
+	else
 		buf->f_type = UFS_MAGIC;
-		buf->f_blocks = uspi->s_dsize;
-	}
-	buf->f_bfree = ufs_blkstofrags(uspi->cs_total.cs_nbfree) +
-		uspi->cs_total.cs_nffree;
+
+	buf->f_blocks = uspi->s_dsize;
+	buf->f_bfree = ufs_freefrags(uspi);
 	buf->f_ffree = uspi->cs_total.cs_nifree;
 	buf->f_bsize = sb->s_blocksize;
-	buf->f_bavail = (buf->f_bfree > (((long)buf->f_blocks / 100) * uspi->s_minfree))
-		? (buf->f_bfree - (((long)buf->f_blocks / 100) * uspi->s_minfree)) : 0;
+	buf->f_bavail = (buf->f_bfree > uspi->s_root_blocks)
+		? (buf->f_bfree - uspi->s_root_blocks) : 0;
 	buf->f_files = uspi->s_ncg * uspi->s_ipg;
 	buf->f_namelen = UFS_MAXNAMLEN;
 	buf->f_fsid.val[0] = (u32)id;

fs/ufs/ufs_fs.h

@@ -733,10 +733,8 @@ struct ufs_sb_private_info {
 	__u32	s_dblkno;	/* offset of first data after cg */
 	__u32	s_cgoffset;	/* cylinder group offset in cylinder */
 	__u32	s_cgmask;	/* used to calc mod fs_ntrak */
-	__u32	s_size;		/* number of blocks (fragments) in fs */
-	__u32	s_dsize;	/* number of data blocks in fs */
-	__u64	s_u2_size;	/* ufs2: number of blocks (fragments) in fs */
-	__u64	s_u2_dsize;	/*ufs2:  number of data blocks in fs */
+	__u64	s_size;		/* number of blocks (fragments) in fs */
+	__u64	s_dsize;	/* number of data blocks in fs */
 	__u32	s_ncg;		/* number of cylinder groups */
 	__u32	s_bsize;	/* size of basic blocks */
 	__u32	s_fsize;	/* size of fragments */
@@ -793,6 +791,7 @@ struct ufs_sb_private_info {
 	__u32	s_maxsymlinklen;/* upper limit on fast symlinks' size */
 	__s32	fs_magic;       /* filesystem magic */
 	unsigned int s_dirblksize;
+	__u64   s_root_blocks;
 };
 
 /*

fs/ufs/util.h

@@ -350,16 +350,11 @@ static inline void *ubh_get_data_ptr(struct ufs_sb_private_info *uspi,
 #define ubh_blkmap(ubh,begin,bit) \
 	((*ubh_get_addr(ubh, (begin) + ((bit) >> 3)) >> ((bit) & 7)) & (0xff >> (UFS_MAXFRAG - uspi->s_fpb)))
 
-/*
- * Determine the number of available frags given a
- * percentage to hold in reserve.
- */
-static inline s64
-ufs_freespace(struct ufs_sb_private_info *uspi, int percentreserved)
+static inline u64
+ufs_freefrags(struct ufs_sb_private_info *uspi)
 {
 	return ufs_blkstofrags(uspi->cs_total.cs_nbfree) +
-		uspi->cs_total.cs_nffree -
-		(uspi->s_dsize * percentreserved) / 100;
+		uspi->cs_total.cs_nffree;
 }
 
 /*