1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* MTD-based superblock management
4  * Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved.
5  * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
11 #include <linux/mtd/super.h>
17 #include <linux/backing-dev.h>
23  * get a superblock on an MTD-backed filesystem
26 		      struct mtd_info *mtd,  in mtd_get_sb()  argument
33 	sb = sget_dev(fc, MKDEV(MTD_BLOCK_MAJOR, mtd->index));  in mtd_get_sb()
37 	if (sb->s_root) {  in mtd_get_sb()
40 			 mtd->index, mtd->name);  in mtd_get_sb()
41 		put_mtd_device(mtd);  in mtd_get_sb()
45 			 mtd->index, mtd->name);  in mtd_get_sb()
49 		 * contrast to sb->s_bdev that's checked with only  in mtd_get_sb()
50 		 * @sb_lock held, nothing checks sb->s_mtd without also  in mtd_get_sb()
51 		 * holding sb->s_umount and we're holding sb->s_umount  in mtd_get_sb()
54 		sb->s_mtd = mtd;  in mtd_get_sb()
55 		sb->s_bdi = bdi_get(mtd_bdi);  in mtd_get_sb()
61 		sb->s_flags |= SB_ACTIVE;  in mtd_get_sb()
64 	BUG_ON(fc->root);  in mtd_get_sb()
65 	fc->root = dget(sb->s_root);  in mtd_get_sb()
74  * get a superblock on an MTD-backed filesystem by MTD device number
80 	struct mtd_info *mtd;  in mtd_get_sb_by_nr()  local
82 	mtd = get_mtd_device(NULL, mtdnr);  in mtd_get_sb_by_nr()
83 	if (IS_ERR(mtd)) {  in mtd_get_sb_by_nr()
85 		return PTR_ERR(mtd);  in mtd_get_sb_by_nr()
88 	return mtd_get_sb(fc, mtd, fill_super);  in mtd_get_sb_by_nr()
92  * get_tree_mtd - Get a superblock based on a single MTD device
106 	if (!fc->source)  in get_tree_mtd()
109 	pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);  in get_tree_mtd()
112 	 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or  in get_tree_mtd()
113 	 * by name, so that we don't require block device support to be present  in get_tree_mtd()
116 	if (fc->source[0] == 'm' &&  in get_tree_mtd()
117 	    fc->source[1] == 't' &&  in get_tree_mtd()
118 	    fc->source[2] == 'd') {  in get_tree_mtd()
119 		if (fc->source[3] == ':') {  in get_tree_mtd()
120 			struct mtd_info *mtd;  in get_tree_mtd()  local
122 			/* mount by MTD device name */  in get_tree_mtd()
123 			pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",  in get_tree_mtd()
124 				 fc->source + 4);  in get_tree_mtd()
126 			mtd = get_mtd_device_nm(fc->source + 4);  in get_tree_mtd()
127 			if (!IS_ERR(mtd))  in get_tree_mtd()
128 				return mtd_get_sb(fc, mtd, fill_super);  in get_tree_mtd()
130 			errorf(fc, "MTD: MTD device with name \"%s\" not found",  in get_tree_mtd()
131 			       fc->source + 4);  in get_tree_mtd()
133 		} else if (isdigit(fc->source[3])) {  in get_tree_mtd()
134 			/* mount by MTD device number name */  in get_tree_mtd()
137 			mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);  in get_tree_mtd()
140 				pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);  in get_tree_mtd()
147 	/* try the old way - the hack where we allowed users to mount  in get_tree_mtd()
150 	ret = lookup_bdev(fc->source, &dev);  in get_tree_mtd()
152 		errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);  in get_tree_mtd()
162 	if (!(fc->sb_flags & SB_SILENT))  in get_tree_mtd()
163 		errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",  in get_tree_mtd()
164 		       fc->source);  in get_tree_mtd()
165 	return -EINVAL;  in get_tree_mtd()
170  * destroy an MTD-based superblock
175 	put_mtd_device(sb->s_mtd);  in kill_mtd_super()
176 	sb->s_mtd = NULL;  in kill_mtd_super()