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  * - they are if the underlying MTD device is the same
27 	struct mtd_info *mtd = fc->sget_key;  in mtd_test_super()  local
29 	if (sb->s_mtd == fc->sget_key) {  in mtd_test_super()
31 			 mtd->index, mtd->name);  in mtd_test_super()
36 		 sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);  in mtd_test_super()
41  * mark the superblock by the MTD device it is using
42  * - set the device number to be the correct MTD block device for pesuperstence
47 	sb->s_mtd = fc->sget_key;  in mtd_set_super()
48 	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, sb->s_mtd->index);  in mtd_set_super()
49 	sb->s_bdi = bdi_get(mtd_bdi);  in mtd_set_super()
54  * get a superblock on an MTD-backed filesystem
57 		      struct mtd_info *mtd,  in mtd_get_sb()  argument
64 	fc->sget_key = mtd;  in mtd_get_sb()
69 	if (sb->s_root) {  in mtd_get_sb()
72 			 mtd->index, mtd->name);  in mtd_get_sb()
73 		put_mtd_device(mtd);  in mtd_get_sb()
77 			 mtd->index, mtd->name);  in mtd_get_sb()
83 		sb->s_flags |= SB_ACTIVE;  in mtd_get_sb()
86 	BUG_ON(fc->root);  in mtd_get_sb()
87 	fc->root = dget(sb->s_root);  in mtd_get_sb()
96  * get a superblock on an MTD-backed filesystem by MTD device number
102 	struct mtd_info *mtd;  in mtd_get_sb_by_nr()  local
104 	mtd = get_mtd_device(NULL, mtdnr);  in mtd_get_sb_by_nr()
105 	if (IS_ERR(mtd)) {  in mtd_get_sb_by_nr()
107 		return PTR_ERR(mtd);  in mtd_get_sb_by_nr()
110 	return mtd_get_sb(fc, mtd, fill_super);  in mtd_get_sb_by_nr()
114  * get_tree_mtd - Get a superblock based on a single MTD device
128 	if (!fc->source)  in get_tree_mtd()
131 	pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);  in get_tree_mtd()
134 	 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or  in get_tree_mtd()
135 	 * by name, so that we don't require block device support to be present  in get_tree_mtd()
138 	if (fc->source[0] == 'm' &&  in get_tree_mtd()
139 	    fc->source[1] == 't' &&  in get_tree_mtd()
140 	    fc->source[2] == 'd') {  in get_tree_mtd()
141 		if (fc->source[3] == ':') {  in get_tree_mtd()
142 			struct mtd_info *mtd;  in get_tree_mtd()  local
144 			/* mount by MTD device name */  in get_tree_mtd()
145 			pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",  in get_tree_mtd()
146 				 fc->source + 4);  in get_tree_mtd()
148 			mtd = get_mtd_device_nm(fc->source + 4);  in get_tree_mtd()
149 			if (!IS_ERR(mtd))  in get_tree_mtd()
150 				return mtd_get_sb(fc, mtd, fill_super);  in get_tree_mtd()
152 			errorf(fc, "MTD: MTD device with name \"%s\" not found",  in get_tree_mtd()
153 			       fc->source + 4);  in get_tree_mtd()
155 		} else if (isdigit(fc->source[3])) {  in get_tree_mtd()
156 			/* mount by MTD device number name */  in get_tree_mtd()
159 			mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);  in get_tree_mtd()
162 				pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);  in get_tree_mtd()
169 	/* try the old way - the hack where we allowed users to mount  in get_tree_mtd()
172 	bdev = lookup_bdev(fc->source);  in get_tree_mtd()
175 		errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);  in get_tree_mtd()
180 	major = MAJOR(bdev->bd_dev);  in get_tree_mtd()
181 	mtdnr = MINOR(bdev->bd_dev);  in get_tree_mtd()
189 	if (!(fc->sb_flags & SB_SILENT))  in get_tree_mtd()
190 		errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",  in get_tree_mtd()
191 		       fc->source);  in get_tree_mtd()
192 	return -EINVAL;  in get_tree_mtd()
197  * destroy an MTD-based superblock
202 	put_mtd_device(sb->s_mtd);  in kill_mtd_super()
203 	sb->s_mtd = NULL;  in kill_mtd_super()