Commit cda2ed05 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

fs: simplify vfs_get_super 



Remove the pointless keying argument and associated enum and pass the
fill_super callback and a "bool reconf" instead.  Also mark the function
static given that there are no users outside of super.c.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3aca4712

Documentation/filesystems/mount_api.rst

+0 −11
Original line number Diff line number Diff line
@@ -562,17 +562,6 @@ or looking up of superblocks. 


The following helpers all wrap sget_fc():



   * ::



       int vfs_get_super(struct fs_context *fc,

		         enum vfs_get_super_keying keying,

		         int (*fill_super)(struct super_block *sb,

					   struct fs_context *fc))



     This creates/looks up a deviceless superblock.  The keying indicates how

     many superblocks of this type may exist and in what manner they may be

     shared:



	(1) vfs_get_single_super



	    Only one such superblock may exist in the system.  Any further

fs/super.c

+9 −51
Original line number Diff line number Diff line
@@ -1111,55 +1111,14 @@ static int test_single_super(struct super_block *s, struct fs_context *fc) 
	return 1;

}



/**

 * vfs_get_super - Get a superblock with a search key set in s_fs_info.

 * @fc: The filesystem context holding the parameters

 * @keying: How to distinguish superblocks

 * @fill_super: Helper to initialise a new superblock

 *

 * Search for a superblock and create a new one if not found.  The search

 * criterion is controlled by @keying.  If the search fails, a new superblock

 * is created and @fill_super() is called to initialise it.

 *

 * @keying can take one of a number of values:

 *

 * (1) vfs_get_single_super - Only one superblock of this type may exist on the

 *     system.  This is typically used for special system filesystems.

 *

 * (2) vfs_get_keyed_super - Multiple superblocks may exist, but they must have

 *     distinct keys (where the key is in s_fs_info).  Searching for the same

 *     key again will turn up the superblock for that key.

 *

 * (3) vfs_get_independent_super - Multiple superblocks may exist and are

 *     unkeyed.  Each call will get a new superblock.

 *

 * A permissions check is made by sget_fc() unless we're getting a superblock

 * for a kernel-internal mount or a submount.

 */

int vfs_get_super(struct fs_context *fc,

		  enum vfs_get_super_keying keying,

static int vfs_get_super(struct fs_context *fc, bool reconf,

		int (*test)(struct super_block *, struct fs_context *),

		int (*fill_super)(struct super_block *sb,

				  struct fs_context *fc))

{

	int (*test)(struct super_block *, struct fs_context *);

	struct super_block *sb;

	int err;



	switch (keying) {

	case vfs_get_single_super:

	case vfs_get_single_reconf_super:

		test = test_single_super;

		break;

	case vfs_get_keyed_super:

		test = test_keyed_super;

		break;

	case vfs_get_independent_super:

		test = NULL;

		break;

	default:

		BUG();

	}



	sb = sget_fc(fc, test, set_anon_super_fc);

	if (IS_ERR(sb))

		return PTR_ERR(sb);
@@ -1173,7 +1132,7 @@ int vfs_get_super(struct fs_context *fc, 
		fc->root = dget(sb->s_root);

	} else {

		fc->root = dget(sb->s_root);

		if (keying == vfs_get_single_reconf_super) {

		if (reconf) {

			err = reconfigure_super(fc);

			if (err < 0) {

				dput(fc->root);
@@ -1189,13 +1148,12 @@ int vfs_get_super(struct fs_context *fc, 
	deactivate_locked_super(sb);

	return err;

}

EXPORT_SYMBOL(vfs_get_super);



int get_tree_nodev(struct fs_context *fc,

		  int (*fill_super)(struct super_block *sb,

				    struct fs_context *fc))

{

	return vfs_get_super(fc, vfs_get_independent_super, fill_super);

	return vfs_get_super(fc, false, NULL, fill_super);

}

EXPORT_SYMBOL(get_tree_nodev);
@@ -1203,7 +1161,7 @@ int get_tree_single(struct fs_context *fc, 
		  int (*fill_super)(struct super_block *sb,

				    struct fs_context *fc))

{

	return vfs_get_super(fc, vfs_get_single_super, fill_super);

	return vfs_get_super(fc, false, test_single_super, fill_super);

}

EXPORT_SYMBOL(get_tree_single);
@@ -1211,7 +1169,7 @@ int get_tree_single_reconf(struct fs_context *fc, 
		  int (*fill_super)(struct super_block *sb,

				    struct fs_context *fc))

{

	return vfs_get_super(fc, vfs_get_single_reconf_super, fill_super);

	return vfs_get_super(fc, true, test_single_super, fill_super);

}

EXPORT_SYMBOL(get_tree_single_reconf);
@@ -1221,7 +1179,7 @@ int get_tree_keyed(struct fs_context *fc, 
		void *key)

{

	fc->s_fs_info = key;

	return vfs_get_super(fc, vfs_get_keyed_super, fill_super);

	return vfs_get_super(fc, false, test_keyed_super, fill_super);

}

EXPORT_SYMBOL(get_tree_keyed);

include/linux/fs_context.h

+0 −14
Original line number Diff line number Diff line
@@ -145,20 +145,6 @@ extern void fc_drop_locked(struct fs_context *fc); 
int reconfigure_single(struct super_block *s,

		       int flags, void *data);



/*

 * sget() wrappers to be called from the ->get_tree() op.

 */

enum vfs_get_super_keying {

	vfs_get_single_super,	/* Only one such superblock may exist */

	vfs_get_single_reconf_super, /* As above, but reconfigure if it exists */

	vfs_get_keyed_super,	/* Superblocks with different s_fs_info keys may exist */

	vfs_get_independent_super, /* Multiple independent superblocks may exist */

};

extern int vfs_get_super(struct fs_context *fc,

			 enum vfs_get_super_keying keying,

			 int (*fill_super)(struct super_block *sb,

					   struct fs_context *fc));



extern int get_tree_nodev(struct fs_context *fc,

			 int (*fill_super)(struct super_block *sb,

					   struct fs_context *fc));