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 up_write(&sb
->s_umount
);
83 sb
->s_flags
|= MS_ACTIVE
;
84 simple_set_mnt(mnt
, sb
);
88 /* new mountpoint for an already mounted superblock */
90 DEBUG(1, "MTDSB: Device %d (\"%s\") is already mounted\n",
91 mtd
->index
, mtd
->name
);
92 simple_set_mnt(mnt
, sb
);
104 * get a superblock on an MTD-backed filesystem by MTD device number
106 static int get_sb_mtd_nr(struct file_system_type
*fs_type
, int flags
,
107 const char *dev_name
, void *data
, int mtdnr
,
108 int (*fill_super
)(struct super_block
*, void *, int),
109 struct vfsmount
*mnt
)
111 struct mtd_info
*mtd
;
113 mtd
= get_mtd_device(NULL
, mtdnr
);
115 DEBUG(0, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr
);
119 return get_sb_mtd_aux(fs_type
, flags
, dev_name
, data
, mtd
, fill_super
,
124 * set up an MTD-based superblock
126 int get_sb_mtd(struct file_system_type
*fs_type
, int flags
,
127 const char *dev_name
, void *data
,
128 int (*fill_super
)(struct super_block
*, void *, int),
129 struct vfsmount
*mnt
)
132 struct block_device
*bdev
;
140 DEBUG(2, "MTDSB: dev_name \"%s\"\n", dev_name
);
142 /* the preferred way of mounting in future; especially when
143 * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
144 * by name, so that we don't require block device support to be present
146 if (dev_name
[0] == 'm' && dev_name
[1] == 't' && dev_name
[2] == 'd') {
147 if (dev_name
[3] == ':') {
148 struct mtd_info
*mtd
;
150 /* mount by MTD device name */
151 DEBUG(1, "MTDSB: mtd:%%s, name \"%s\"\n",
154 for (mtdnr
= 0; mtdnr
< MAX_MTD_DEVICES
; mtdnr
++) {
155 mtd
= get_mtd_device(NULL
, mtdnr
);
157 if (!strcmp(mtd
->name
, dev_name
+ 4))
158 return get_sb_mtd_aux(
167 printk(KERN_NOTICE
"MTD:"
168 " MTD device with name \"%s\" not found.\n",
171 } else if (isdigit(dev_name
[3])) {
172 /* mount by MTD device number name */
175 mtdnr
= simple_strtoul(dev_name
+ 3, &endptr
, 0);
177 /* It was a valid number */
178 DEBUG(1, "MTDSB: mtd%%d, mtdnr %d\n",
180 return get_sb_mtd_nr(fs_type
, flags
,
182 mtdnr
, fill_super
, mnt
);
188 /* try the old way - the hack where we allowed users to mount
189 * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
191 bdev
= lookup_bdev(dev_name
);
194 DEBUG(1, "MTDSB: lookup_bdev() returned %d\n", ret
);
197 DEBUG(1, "MTDSB: lookup_bdev() returned 0\n");
201 major
= MAJOR(bdev
->bd_dev
);
202 mtdnr
= MINOR(bdev
->bd_dev
);
205 if (major
!= MTD_BLOCK_MAJOR
)
206 goto not_an_MTD_device
;
208 return get_sb_mtd_nr(fs_type
, flags
, dev_name
, data
, mtdnr
, fill_super
,
212 #endif /* CONFIG_BLOCK */
214 if (!(flags
& MS_SILENT
))
216 "MTD: Attempt to mount non-MTD device \"%s\"\n",
221 EXPORT_SYMBOL_GPL(get_sb_mtd
);
224 * destroy an MTD-based superblock
226 void kill_mtd_super(struct super_block
*sb
)
228 generic_shutdown_super(sb
);
229 put_mtd_device(sb
->s_mtd
);
233 EXPORT_SYMBOL_GPL(kill_mtd_super
);
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