[PATCH] propagate mode through open_bdev_excl/close_bdev_excl

replace open_bdev_excl/close_bdev_excl with variants taking fmode_t.
superblock gets the value used to mount it stored in sb->s_mode

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

6 files changed, 31 insertions, 24 deletions

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 91fbba76763..8c295f40d2a 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -224,7 +224,7 @@ static void block2mtd_free_device(struct block2mtd_dev *dev)
 	if (dev->blkdev) {
 		invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 					0, -1);
-		close_bdev_excl(dev->blkdev);
+		close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
 	}
 
 	kfree(dev);
@@ -246,7 +246,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
 		return NULL;
 
 	/* Get a handle on the device */
-	bdev = open_bdev_excl(devname, O_RDWR, NULL);
+	bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
 #ifndef MODULE
 	if (IS_ERR(bdev)) {
 
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 05131baf3cf..4b595904cef 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1309,32 +1309,29 @@ fail:
 EXPORT_SYMBOL(lookup_bdev);
 
 /**
- * open_bdev_excl  -  open a block device by name and set it up for use
+ * open_bdev_exclusive  -  open a block device by name and set it up for use
  *
  * @path:	special file representing the block device
- * @flags:	%MS_RDONLY for opening read-only
+ * @mode:	FMODE_... combination to pass be used
  * @holder:	owner for exclusion
  *
  * Open the blockdevice described by the special file at @path, claim it
  * for the @holder.
  */
-struct block_device *open_bdev_excl(const char *path, int flags, void *holder)
+struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
 {
 	struct block_device *bdev;
-	fmode_t mode = FMODE_READ;
 	int error = 0;
 
 	bdev = lookup_bdev(path);
 	if (IS_ERR(bdev))
 		return bdev;
 
-	if (!(flags & MS_RDONLY))
-		mode |= FMODE_WRITE;
 	error = blkdev_get(bdev, mode, 0);
 	if (error)
 		return ERR_PTR(error);
 	error = -EACCES;
-	if (!(flags & MS_RDONLY) && bdev_read_only(bdev))
+	if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
 		goto blkdev_put;
 	error = bd_claim(bdev, holder);
 	if (error)
@@ -1347,22 +1344,23 @@ blkdev_put:
 	return ERR_PTR(error);
 }
 
-EXPORT_SYMBOL(open_bdev_excl);
+EXPORT_SYMBOL(open_bdev_exclusive);
 
 /**
- * close_bdev_excl  -  release a blockdevice openen by open_bdev_excl()
+ * close_bdev_exclusive  -  close a blockdevice opened by open_bdev_exclusive()
  *
  * @bdev:	blockdevice to close
+ * @mode:	mode, must match that used to open.
  *
- * This is the counterpart to open_bdev_excl().
+ * This is the counterpart to open_bdev_exclusive().
  */
-void close_bdev_excl(struct block_device *bdev)
+void close_bdev_exclusive(struct block_device *bdev, fmode_t mode)
 {
 	bd_release(bdev);
-	blkdev_put(bdev, 0);	/* move up in the next patches */
+	blkdev_put(bdev, mode);
 }
 
-EXPORT_SYMBOL(close_bdev_excl);
+EXPORT_SYMBOL(close_bdev_exclusive);
 
 int __invalidate_device(struct block_device *bdev)
 {
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 3261518478f..70b89607667 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -2628,7 +2628,8 @@ static int journal_init_dev(struct super_block *super,
 		return 0;
 	}
 
-	journal->j_dev_bd = open_bdev_excl(jdev_name, 0, journal);
+	journal->j_dev_bd = open_bdev_exclusive(jdev_name,
+						FMODE_READ|FMODE_WRITE, journal);
 	if (IS_ERR(journal->j_dev_bd)) {
 		result = PTR_ERR(journal->j_dev_bd);
 		journal->j_dev_bd = NULL;
diff --git a/fs/super.c b/fs/super.c
index e931ae9511f..0d77ac20d03 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -760,9 +760,13 @@ int get_sb_bdev(struct file_system_type *fs_type,
 {
 	struct block_device *bdev;
 	struct super_block *s;
+	fmode_t mode = FMODE_READ;
 	int error = 0;
 
-	bdev = open_bdev_excl(dev_name, flags, fs_type);
+	if (!(flags & MS_RDONLY))
+		mode |= FMODE_WRITE;
+
+	bdev = open_bdev_exclusive(dev_name, mode, fs_type);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
@@ -785,11 +789,12 @@ int get_sb_bdev(struct file_system_type *fs_type,
 			goto error_bdev;
 		}
 
-		close_bdev_excl(bdev);
+		close_bdev_exclusive(bdev, mode);
 	} else {
 		char b[BDEVNAME_SIZE];
 
 		s->s_flags = flags;
+		s->s_mode = mode;
 		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
 		sb_set_blocksize(s, block_size(bdev));
 		error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
@@ -807,7 +812,7 @@ int get_sb_bdev(struct file_system_type *fs_type,
 error_s:
 	error = PTR_ERR(s);
 error_bdev:
-	close_bdev_excl(bdev);
+	close_bdev_exclusive(bdev, mode);
 error:
 	return error;
 }
@@ -817,10 +822,11 @@ EXPORT_SYMBOL(get_sb_bdev);
 void kill_block_super(struct super_block *sb)
 {
 	struct block_device *bdev = sb->s_bdev;
+	fmode_t mode = sb->s_mode;
 
 	generic_shutdown_super(sb);
 	sync_blockdev(bdev);
-	close_bdev_excl(bdev);
+	close_bdev_exclusive(bdev, mode);
 }
 
 EXPORT_SYMBOL(kill_block_super);
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index e39013619b2..37ebe36056e 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -589,7 +589,7 @@ xfs_blkdev_get(
 {
 	int			error = 0;
 
-	*bdevp = open_bdev_excl(name, 0, mp);
+	*bdevp = open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp);
 	if (IS_ERR(*bdevp)) {
 		error = PTR_ERR(*bdevp);
 		printk("XFS: Invalid device [%s], error=%d\n", name, error);
@@ -603,7 +603,7 @@ xfs_blkdev_put(
 	struct block_device	*bdev)
 {
 	if (bdev)
-		close_bdev_excl(bdev);
+		close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
 }
 
 /*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 04c8dc41f45..c6766314dc5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1157,6 +1157,7 @@ struct super_block {
 	char s_id[32];				/* Informational name */
 
 	void 			*s_fs_info;	/* Filesystem private info */
+	fmode_t			s_mode;
 
 	/*
 	 * The next field is for VFS *only*. No filesystems have any business
@@ -1753,9 +1754,10 @@ extern void chrdev_show(struct seq_file *,off_t);
 extern const char *__bdevname(dev_t, char *buffer);
 extern const char *bdevname(struct block_device *bdev, char *buffer);
 extern struct block_device *lookup_bdev(const char *);
-extern struct block_device *open_bdev_excl(const char *, int, void *);
-extern void close_bdev_excl(struct block_device *);
+extern struct block_device *open_bdev_exclusive(const char *, fmode_t, void *);
+extern void close_bdev_exclusive(struct block_device *, fmode_t);
 extern void blkdev_show(struct seq_file *,off_t);
+
 #else
 #define BLKDEV_MAJOR_HASH_SIZE	0
 #endif