ufs: kill lock_ufs()

There were 3 remaining users; in two of them we took ->s_lock immediately
after lock_ufs() and held it until just before unlock_ufs(); the third
one (statfs) could not be called from itself or from other two (remount
and sync_fs).  Just use ->s_lock in statfs and don't bother with lock_ufs
at all.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ufs/super.c

@@ -94,22 +94,6 @@
 #include "swab.h"
 #include "util.h"
 
-void lock_ufs(struct super_block *sb)
-{
-	struct ufs_sb_info *sbi = UFS_SB(sb);
-
-	mutex_lock(&sbi->mutex);
-	sbi->mutex_owner = current;
-}
-
-void unlock_ufs(struct super_block *sb)
-{
-	struct ufs_sb_info *sbi = UFS_SB(sb);
-
-	sbi->mutex_owner = NULL;
-	mutex_unlock(&sbi->mutex);
-}
-
 static struct inode *ufs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
 {
 	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
@@ -694,7 +678,6 @@ static int ufs_sync_fs(struct super_block *sb, int wait)
 	struct ufs_super_block_third * usb3;
 	unsigned flags;
 
-	lock_ufs(sb);
 	mutex_lock(&UFS_SB(sb)->s_lock);
 
 	UFSD("ENTER\n");
@@ -714,7 +697,6 @@ static int ufs_sync_fs(struct super_block *sb, int wait)
 
 	UFSD("EXIT\n");
 	mutex_unlock(&UFS_SB(sb)->s_lock);
-	unlock_ufs(sb);
 
 	return 0;
 }
@@ -758,7 +740,6 @@ static void ufs_put_super(struct super_block *sb)
 
 	ubh_brelse_uspi (sbi->s_uspi);
 	kfree (sbi->s_uspi);
-	mutex_destroy(&sbi->mutex);
 	kfree (sbi);
 	sb->s_fs_info = NULL;
 	UFSD("EXIT\n");
@@ -801,7 +782,6 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 
 	UFSD("flag %u\n", (int)(sb->s_flags & MS_RDONLY));
 	
-	mutex_init(&sbi->mutex);
 	mutex_init(&sbi->s_lock);
 	spin_lock_init(&sbi->work_lock);
 	INIT_DELAYED_WORK(&sbi->sync_work, delayed_sync_fs);
@@ -1257,7 +1237,6 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 	return 0;
 
 failed:
-	mutex_destroy(&sbi->mutex);
 	if (ubh)
 		ubh_brelse_uspi (uspi);
 	kfree (uspi);
@@ -1280,7 +1259,6 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	unsigned flags;
 
 	sync_filesystem(sb);
-	lock_ufs(sb);
 	mutex_lock(&UFS_SB(sb)->s_lock);
 	uspi = UFS_SB(sb)->s_uspi;
 	flags = UFS_SB(sb)->s_flags;
@@ -1296,7 +1274,6 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	ufs_set_opt (new_mount_opt, ONERROR_LOCK);
 	if (!ufs_parse_options (data, &new_mount_opt)) {
 		mutex_unlock(&UFS_SB(sb)->s_lock);
-		unlock_ufs(sb);
 		return -EINVAL;
 	}
 	if (!(new_mount_opt & UFS_MOUNT_UFSTYPE)) {
@@ -1304,14 +1281,12 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	} else if ((new_mount_opt & UFS_MOUNT_UFSTYPE) != ufstype) {
 		pr_err("ufstype can't be changed during remount\n");
 		mutex_unlock(&UFS_SB(sb)->s_lock);
-		unlock_ufs(sb);
 		return -EINVAL;
 	}
 
 	if ((*mount_flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
 		UFS_SB(sb)->s_mount_opt = new_mount_opt;
 		mutex_unlock(&UFS_SB(sb)->s_lock);
-		unlock_ufs(sb);
 		return 0;
 	}
 	
@@ -1335,7 +1310,6 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 #ifndef CONFIG_UFS_FS_WRITE
 		pr_err("ufs was compiled with read-only support, can't be mounted as read-write\n");
 		mutex_unlock(&UFS_SB(sb)->s_lock);
-		unlock_ufs(sb);
 		return -EINVAL;
 #else
 		if (ufstype != UFS_MOUNT_UFSTYPE_SUN && 
@@ -1345,13 +1319,11 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 		    ufstype != UFS_MOUNT_UFSTYPE_UFS2) {
 			pr_err("this ufstype is read-only supported\n");
 			mutex_unlock(&UFS_SB(sb)->s_lock);
-			unlock_ufs(sb);
 			return -EINVAL;
 		}
 		if (!ufs_read_cylinder_structures(sb)) {
 			pr_err("failed during remounting\n");
 			mutex_unlock(&UFS_SB(sb)->s_lock);
-			unlock_ufs(sb);
 			return -EPERM;
 		}
 		sb->s_flags &= ~MS_RDONLY;
@@ -1359,7 +1331,6 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	}
 	UFS_SB(sb)->s_mount_opt = new_mount_opt;
 	mutex_unlock(&UFS_SB(sb)->s_lock);
-	unlock_ufs(sb);
 	return 0;
 }
 
@@ -1391,8 +1362,7 @@ static int ufs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct ufs_super_block_third *usb3;
 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 
-	lock_ufs(sb);
-
+	mutex_lock(&UFS_SB(sb)->s_lock);
 	usb3 = ubh_get_usb_third(uspi);
 	
 	if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2) {
@@ -1413,7 +1383,7 @@ static int ufs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_fsid.val[0] = (u32)id;
 	buf->f_fsid.val[1] = (u32)(id >> 32);
 
-	unlock_ufs(sb);
+	mutex_unlock(&UFS_SB(sb)->s_lock);
 
 	return 0;
 }

fs/ufs/ufs.h

@@ -24,8 +24,6 @@ struct ufs_sb_info {
 	unsigned s_cgno[UFS_MAX_GROUP_LOADED];
 	unsigned short s_cg_loaded;
 	unsigned s_mount_opt;
-	struct mutex mutex;
-	struct task_struct *mutex_owner;
 	struct super_block *sb;
 	int work_queued; /* non-zero if the delayed work is queued */
 	struct delayed_work sync_work; /* FS sync delayed work */
@@ -172,7 +170,4 @@ static inline u32 ufs_dtogd(struct ufs_sb_private_info * uspi, u64 b)
 	return do_div(b, uspi->s_fpg);
 }
 
-extern void lock_ufs(struct super_block *sb);
-extern void unlock_ufs(struct super_block *sb);
-
 #endif /* _UFS_UFS_H */