1 /* MTD-based superblock management
3 * Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved.
4 * Written by: David Howells <dhowells@redhat.com>
5 * David Woodhouse <dwmw2@infradead.org>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/mtd/super.h>
14 #include <linux/namei.h>
15 #include <linux/ctype.h>
18 * compare superblocks to see if they're equivalent
19 * - they are if the underlying MTD device is the same
21 static int get_sb_mtd_compare(struct super_block
*sb
, void *_mtd
)
23 struct mtd_info
*mtd
= _mtd
;
25 if (sb
->s_mtd
== mtd
) {
26 DEBUG(2, "MTDSB: Match on device %d (\"%s\")\n",
27 mtd
->index
, mtd
->name
);
31 DEBUG(2, "MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
32 sb
->s_mtd
->index
, sb
->s_mtd
->name
, mtd
->index
, mtd
->name
);
37 * mark the superblock by the MTD device it is using
38 * - set the device number to be the correct MTD block device for pesuperstence
41 static int get_sb_mtd_set(struct super_block
*sb
, void *_mtd
)
43 struct mtd_info
*mtd
= _mtd
;
46 sb
->s_dev
= MKDEV(MTD_BLOCK_MAJOR
, mtd
->index
);
51 * get a superblock on an MTD-backed filesystem
53 static int get_sb_mtd_aux(struct file_system_type
*fs_type
, int flags
,
54 const char *dev_name
, void *data
,
56 int (*fill_super
)(struct super_block
*, void *, int),
59 struct super_block
*sb
;
62 sb
= sget(fs_type
, get_sb_mtd_compare
, get_sb_mtd_set
, mtd
);
69 /* fresh new superblock */
70 DEBUG(1, "MTDSB: New superblock for device %d (\"%s\")\n",
71 mtd
->index
, mtd
->name
);
75 ret
= fill_super(sb
, data
, flags
& MS_SILENT
? 1 : 0);
77 deactivate_locked_super(sb
);
82 sb
->s_flags
|= MS_ACTIVE
;
83 simple_set_mnt(mnt
, sb
);
87 /* new mountpoint for an already mounted superblock */
89 DEBUG(1, "MTDSB: Device %d (\"%s\") is already mounted\n",
90 mtd
->index
, mtd
->name
);
91 simple_set_mnt(mnt
, sb
);
103 * get a superblock on an MTD-backed filesystem by MTD device number
105 static int get_sb_mtd_nr(struct file_system_type
*fs_type
, int flags
,
106 const char *dev_name
, void *data
, int mtdnr
,
107 int (*fill_super
)(struct super_block
*, void *, int),
108 struct vfsmount
*mnt
)
110 struct mtd_info
*mtd
;
112 mtd
= get_mtd_device(NULL
, mtdnr
);
114 DEBUG(0, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr
);
118 return get_sb_mtd_aux(fs_type
, flags
, dev_name
, data
, mtd
, fill_super
,
123 * set up an MTD-based superblock
125 int get_sb_mtd(struct file_system_type
*fs_type
, int flags
,
126 const char *dev_name
, void *data
,
127 int (*fill_super
)(struct super_block
*, void *, int),
128 struct vfsmount
*mnt
)
131 struct block_device
*bdev
;
139 DEBUG(2, "MTDSB: dev_name \"%s\"\n", dev_name
);
141 /* the preferred way of mounting in future; especially when
142 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
143 * by name, so that we don't require block device support to be present
145 if (dev_name
[0] == 'm' && dev_name
[1] == 't' && dev_name
[2] == 'd') {
146 if (dev_name
[3] == ':') {
147 struct mtd_info
*mtd
;
149 /* mount by MTD device name */
150 DEBUG(1, "MTDSB: mtd:%%s, name \"%s\"\n",
153 for (mtdnr
= 0; mtdnr
< MAX_MTD_DEVICES
; mtdnr
++) {
154 mtd
= get_mtd_device(NULL
, mtdnr
);
156 if (!strcmp(mtd
->name
, dev_name
+ 4))
157 return get_sb_mtd_aux(
166 printk(KERN_NOTICE
"MTD:"
167 " MTD device with name \"%s\" not found.\n",
170 } else if (isdigit(dev_name
[3])) {
171 /* mount by MTD device number name */
174 mtdnr
= simple_strtoul(dev_name
+ 3, &endptr
, 0);
176 /* It was a valid number */
177 DEBUG(1, "MTDSB: mtd%%d, mtdnr %d\n",
179 return get_sb_mtd_nr(fs_type
, flags
,
181 mtdnr
, fill_super
, mnt
);
187 /* try the old way - the hack where we allowed users to mount
188 * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
190 bdev
= lookup_bdev(dev_name
);
193 DEBUG(1, "MTDSB: lookup_bdev() returned %d\n", ret
);
196 DEBUG(1, "MTDSB: lookup_bdev() returned 0\n");
200 major
= MAJOR(bdev
->bd_dev
);
201 mtdnr
= MINOR(bdev
->bd_dev
);
204 if (major
!= MTD_BLOCK_MAJOR
)
205 goto not_an_MTD_device
;
207 return get_sb_mtd_nr(fs_type
, flags
, dev_name
, data
, mtdnr
, fill_super
,
211 #endif /* CONFIG_BLOCK */
213 if (!(flags
& MS_SILENT
))
215 "MTD: Attempt to mount non-MTD device \"%s\"\n",
220 EXPORT_SYMBOL_GPL(get_sb_mtd
);
223 * destroy an MTD-based superblock
225 void kill_mtd_super(struct super_block
*sb
)
227 generic_shutdown_super(sb
);
228 put_mtd_device(sb
->s_mtd
);
232 EXPORT_SYMBOL_GPL(kill_mtd_super
);
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