]> err.no Git - linux-2.6/commitdiff
[PATCH] Remove blkmtd
authorJoern Engel <joern@wohnheim.fh-wedel.de>
Tue, 11 Apr 2006 05:54:17 +0000 (22:54 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Tue, 11 Apr 2006 13:18:43 +0000 (06:18 -0700)
Remove the blkmtd driver.

- An alternative exists (block2mtd) that hasn't had  bug report for > 1 year.

- Most embedded people tend to use ancient kernels with custom patches from
  mtd cvs and elsewhere, so the 1 year warning period neither helps nor hurts
  them too much.

- It's in the way of klibc.  The problems caused by pulling blkmtd support
  are fairly low, while the problems caused by delaying klibc can be fairly
  substantial.  At best, this would be a severe burden on hpa's time.

Signed-off-by: Joern Engel <joern@wohnheim.fh-wedel.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/mtd/devices/Kconfig
drivers/mtd/devices/Makefile
drivers/mtd/devices/blkmtd.c [deleted file]

index dd628cb51e312e0a109fad6e13b7d1cda7ca06bb..7fac438b5c32cbc376a9dc4945247a767a42fc55 100644 (file)
@@ -129,8 +129,8 @@ config MTDRAM_ABS_POS
          allocating space from Linux's available memory. Otherwise, leave
          this set to zero. Most people will want to leave this as zero.
 
-config MTD_BLKMTD
-       tristate "MTD emulation using block device"
+config MTD_BLOCK2MTD
+       tristate "MTD using block device"
        depends on MTD
        help
          This driver allows a block device to appear as an MTD. It would
@@ -141,15 +141,6 @@ config MTD_BLKMTD
          Testing MTD users (eg JFFS2) on large media and media that might
          be removed during a write (using the floppy drive).
 
-config MTD_BLOCK2MTD
-       tristate "MTD using block device (rewrite)"
-       depends on MTD && EXPERIMENTAL
-       help
-         This driver is basically the same at MTD_BLKMTD above, but
-         experienced some interface changes plus serious speedups.  In
-         the long term, it should replace MTD_BLKMTD.  Right now, you
-         shouldn't entrust important data to it yet.
-
 comment "Disk-On-Chip Device Drivers"
 
 config MTD_DOC2000
index 7c5ed2178380119b074f738ea14d5e6b5fd1e345..b6573670316f198e02b3df9d0eafc12fc5e96d48 100644 (file)
@@ -21,7 +21,6 @@ obj-$(CONFIG_MTD_PMC551)      += pmc551.o
 obj-$(CONFIG_MTD_MS02NV)       += ms02-nv.o
 obj-$(CONFIG_MTD_MTDRAM)       += mtdram.o
 obj-$(CONFIG_MTD_LART)         += lart.o
-obj-$(CONFIG_MTD_BLKMTD)       += blkmtd.o
 obj-$(CONFIG_MTD_BLOCK2MTD)    += block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)    += mtd_dataflash.o
 obj-$(CONFIG_MTD_M25P80)       += m25p80.o
diff --git a/drivers/mtd/devices/blkmtd.c b/drivers/mtd/devices/blkmtd.c
deleted file mode 100644 (file)
index 79f2e1f..0000000
+++ /dev/null
@@ -1,819 +0,0 @@
-/*
- * $Id: blkmtd.c,v 1.27 2005/11/07 11:14:24 gleixner Exp $
- *
- * blkmtd.c - use a block device as a fake MTD
- *
- * Author: Simon Evans <spse@secret.org.uk>
- *
- * Copyright (C) 2001,2002 Simon Evans
- *
- * Licence: GPL
- *
- * How it works:
- *     The driver uses raw/io to read/write the device and the page
- *     cache to cache access. Writes update the page cache with the
- *     new data and mark it dirty and add the page into a BIO which
- *     is then written out.
- *
- *     It can be loaded Read-Only to prevent erases and writes to the
- *     medium.
- *
- */
-
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/blkdev.h>
-#include <linux/bio.h>
-#include <linux/pagemap.h>
-#include <linux/list.h>
-#include <linux/init.h>
-#include <linux/mount.h>
-#include <linux/mtd/mtd.h>
-#include <linux/mutex.h>
-
-#define err(format, arg...) printk(KERN_ERR "blkmtd: " format "\n" , ## arg)
-#define info(format, arg...) printk(KERN_INFO "blkmtd: " format "\n" , ## arg)
-#define warn(format, arg...) printk(KERN_WARNING "blkmtd: " format "\n" , ## arg)
-#define crit(format, arg...) printk(KERN_CRIT "blkmtd: " format "\n" , ## arg)
-
-
-/* Default erase size in K, always make it a multiple of PAGE_SIZE */
-#define CONFIG_MTD_BLKDEV_ERASESIZE (128 << 10)        /* 128KiB */
-#define VERSION "$Revision: 1.27 $"
-
-/* Info for the block device */
-struct blkmtd_dev {
-       struct list_head list;
-       struct block_device *blkdev;
-       struct mtd_info mtd_info;
-       struct mutex wrbuf_mutex;
-};
-
-
-/* Static info about the MTD, used in cleanup_module */
-static LIST_HEAD(blkmtd_device_list);
-
-
-static void blkmtd_sync(struct mtd_info *mtd);
-
-#define MAX_DEVICES 4
-
-/* Module parameters passed by insmod/modprobe */
-static char *device[MAX_DEVICES];    /* the block device to use */
-static int erasesz[MAX_DEVICES];     /* optional default erase size */
-static int ro[MAX_DEVICES];          /* optional read only flag */
-static int sync;
-
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Simon Evans <spse@secret.org.uk>");
-MODULE_DESCRIPTION("Emulate an MTD using a block device");
-module_param_array(device, charp, NULL, 0);
-MODULE_PARM_DESC(device, "block device to use");
-module_param_array(erasesz, int, NULL, 0);
-MODULE_PARM_DESC(erasesz, "optional erase size to use in KiB. eg 4=4KiB.");
-module_param_array(ro, bool, NULL, 0);
-MODULE_PARM_DESC(ro, "1=Read only, writes and erases cause errors");
-module_param(sync, bool, 0);
-MODULE_PARM_DESC(sync, "1=Synchronous writes");
-
-
-/* completion handler for BIO reads */
-static int bi_read_complete(struct bio *bio, unsigned int bytes_done, int error)
-{
-       if (bio->bi_size)
-               return 1;
-
-       complete((struct completion*)bio->bi_private);
-       return 0;
-}
-
-
-/* completion handler for BIO writes */
-static int bi_write_complete(struct bio *bio, unsigned int bytes_done, int error)
-{
-       const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-       struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-
-       if (bio->bi_size)
-               return 1;
-
-       if(!uptodate)
-               err("bi_write_complete: not uptodate\n");
-
-       do {
-               struct page *page = bvec->bv_page;
-               DEBUG(3, "Cleaning up page %ld\n", page->index);
-               if (--bvec >= bio->bi_io_vec)
-                       prefetchw(&bvec->bv_page->flags);
-
-               if (uptodate) {
-                       SetPageUptodate(page);
-               } else {
-                       ClearPageUptodate(page);
-                       SetPageError(page);
-               }
-               clear_page_dirty(page);
-               unlock_page(page);
-               page_cache_release(page);
-       } while (bvec >= bio->bi_io_vec);
-
-       complete((struct completion*)bio->bi_private);
-       return 0;
-}
-
-
-/* read one page from the block device */
-static int blkmtd_readpage(struct blkmtd_dev *dev, struct page *page)
-{
-       struct bio *bio;
-       struct completion event;
-       int err = -ENOMEM;
-
-       if(PageUptodate(page)) {
-               DEBUG(2, "blkmtd: readpage page %ld is already upto date\n", page->index);
-               unlock_page(page);
-               return 0;
-       }
-
-       ClearPageUptodate(page);
-       ClearPageError(page);
-
-       bio = bio_alloc(GFP_KERNEL, 1);
-       if(bio) {
-               init_completion(&event);
-               bio->bi_bdev = dev->blkdev;
-               bio->bi_sector = page->index << (PAGE_SHIFT-9);
-               bio->bi_private = &event;
-               bio->bi_end_io = bi_read_complete;
-               if(bio_add_page(bio, page, PAGE_SIZE, 0) == PAGE_SIZE) {
-                       submit_bio(READ_SYNC, bio);
-                       wait_for_completion(&event);
-                       err = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : -EIO;
-                       bio_put(bio);
-               }
-       }
-
-       if(err)
-               SetPageError(page);
-       else
-               SetPageUptodate(page);
-       flush_dcache_page(page);
-       unlock_page(page);
-       return err;
-}
-
-
-/* write out the current BIO and wait for it to finish */
-static int blkmtd_write_out(struct bio *bio)
-{
-       struct completion event;
-       int err;
-
-       if(!bio->bi_vcnt) {
-               bio_put(bio);
-               return 0;
-       }
-
-       init_completion(&event);
-       bio->bi_private = &event;
-       bio->bi_end_io = bi_write_complete;
-       submit_bio(WRITE_SYNC, bio);
-       wait_for_completion(&event);
-       DEBUG(3, "submit_bio completed, bi_vcnt = %d\n", bio->bi_vcnt);
-       err = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : -EIO;
-       bio_put(bio);
-       return err;
-}
-
-
-/**
- * blkmtd_add_page - add a page to the current BIO
- * @bio: bio to add to (NULL to alloc initial bio)
- * @blkdev: block device
- * @page: page to add
- * @pagecnt: pages left to add
- *
- * Adds a page to the current bio, allocating it if necessary. If it cannot be
- * added, the current bio is written out and a new one is allocated. Returns
- * the new bio to add or NULL on error
- */
-static struct bio *blkmtd_add_page(struct bio *bio, struct block_device *blkdev,
-                                  struct page *page, int pagecnt)
-{
-
- retry:
-       if(!bio) {
-               bio = bio_alloc(GFP_KERNEL, pagecnt);
-               if(!bio)
-                       return NULL;
-               bio->bi_sector = page->index << (PAGE_SHIFT-9);
-               bio->bi_bdev = blkdev;
-       }
-
-       if(bio_add_page(bio, page, PAGE_SIZE, 0) != PAGE_SIZE) {
-               blkmtd_write_out(bio);
-               bio = NULL;
-               goto retry;
-       }
-       return bio;
-}
-
-
-/**
- * write_pages - write block of data to device via the page cache
- * @dev: device to write to
- * @buf: data source or NULL if erase (output is set to 0xff)
- * @to: offset into output device
- * @len: amount to data to write
- * @retlen: amount of data written
- *
- * Grab pages from the page cache and fill them with the source data.
- * Non page aligned start and end result in a readin of the page and
- * part of the page being modified. Pages are added to the bio and then written
- * out.
- */
-static int write_pages(struct blkmtd_dev *dev, const u_char *buf, loff_t to,
-                   size_t len, size_t *retlen)
-{
-       int pagenr, offset;
-       size_t start_len = 0, end_len;
-       int pagecnt = 0;
-       int err = 0;
-       struct bio *bio = NULL;
-       size_t thislen = 0;
-
-       pagenr = to >> PAGE_SHIFT;
-       offset = to & ~PAGE_MASK;
-
-       DEBUG(2, "blkmtd: write_pages: buf = %p to = %ld len = %zd pagenr = %d offset = %d\n",
-             buf, (long)to, len, pagenr, offset);
-
-       /* see if we have to do a partial write at the start */
-       if(offset) {
-               start_len = ((offset + len) > PAGE_SIZE) ? PAGE_SIZE - offset : len;
-               len -= start_len;
-       }
-
-       /* calculate the length of the other two regions */
-       end_len = len & ~PAGE_MASK;
-       len -= end_len;
-
-       if(start_len)
-               pagecnt++;
-
-       if(len)
-               pagecnt += len >> PAGE_SHIFT;
-
-       if(end_len)
-               pagecnt++;
-
-       mutex_lock(&dev->wrbuf_mutex);
-
-       DEBUG(3, "blkmtd: write: start_len = %zd len = %zd end_len = %zd pagecnt = %d\n",
-             start_len, len, end_len, pagecnt);
-
-       if(start_len) {
-               /* do partial start region */
-               struct page *page;
-
-               DEBUG(3, "blkmtd: write: doing partial start, page = %d len = %zd offset = %d\n",
-                     pagenr, start_len, offset);
-
-               BUG_ON(!buf);
-               page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
-               lock_page(page);
-               if(PageDirty(page)) {
-                       err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d\n",
-                           to, start_len, len, end_len, pagenr);
-                       BUG();
-               }
-               memcpy(page_address(page)+offset, buf, start_len);
-               set_page_dirty(page);
-               SetPageUptodate(page);
-               buf += start_len;
-               thislen = start_len;
-               bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
-               if(!bio) {
-                       err = -ENOMEM;
-                       err("bio_add_page failed\n");
-                       goto write_err;
-               }
-               pagecnt--;
-               pagenr++;
-       }
-
-       /* Now do the main loop to a page aligned, n page sized output */
-       if(len) {
-               int pagesc = len >> PAGE_SHIFT;
-               DEBUG(3, "blkmtd: write: whole pages start = %d, count = %d\n",
-                     pagenr, pagesc);
-               while(pagesc) {
-                       struct page *page;
-
-                       /* see if page is in the page cache */
-                       DEBUG(3, "blkmtd: write: grabbing page %d from page cache\n", pagenr);
-                       page = grab_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr);
-                       if(PageDirty(page)) {
-                               BUG();
-                       }
-                       if(!page) {
-                               warn("write: cannot grab cache page %d", pagenr);
-                               err = -ENOMEM;
-                               goto write_err;
-                       }
-                       if(!buf) {
-                               memset(page_address(page), 0xff, PAGE_SIZE);
-                       } else {
-                               memcpy(page_address(page), buf, PAGE_SIZE);
-                               buf += PAGE_SIZE;
-                       }
-                       bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
-                       if(!bio) {
-                               err = -ENOMEM;
-                               err("bio_add_page failed\n");
-                               goto write_err;
-                       }
-                       pagenr++;
-                       pagecnt--;
-                       set_page_dirty(page);
-                       SetPageUptodate(page);
-                       pagesc--;
-                       thislen += PAGE_SIZE;
-               }
-       }
-
-       if(end_len) {
-               /* do the third region */
-               struct page *page;
-               DEBUG(3, "blkmtd: write: doing partial end, page = %d len = %zd\n",
-                     pagenr, end_len);
-               BUG_ON(!buf);
-               page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
-               lock_page(page);
-               if(PageDirty(page)) {
-                       err("to = %lld start_len = %zd len = %zd end_len = %zd pagenr = %d\n",
-                           to, start_len, len, end_len, pagenr);
-                       BUG();
-               }
-               memcpy(page_address(page), buf, end_len);
-               set_page_dirty(page);
-               SetPageUptodate(page);
-               DEBUG(3, "blkmtd: write: writing out partial end\n");
-               thislen += end_len;
-               bio = blkmtd_add_page(bio, dev->blkdev, page, pagecnt);
-               if(!bio) {
-                       err = -ENOMEM;
-                       err("bio_add_page failed\n");
-                       goto write_err;
-               }
-               pagenr++;
-       }
-
-       DEBUG(3, "blkmtd: write: got %d vectors to write\n", bio->bi_vcnt);
- write_err:
-       if(bio)
-               blkmtd_write_out(bio);
-
-       DEBUG(2, "blkmtd: write: end, retlen = %zd, err = %d\n", *retlen, err);
-       mutex_unlock(&dev->wrbuf_mutex);
-
-       if(retlen)
-               *retlen = thislen;
-       return err;
-}
-
-
-/* erase a specified part of the device */
-static int blkmtd_erase(struct mtd_info *mtd, struct erase_info *instr)
-{
-       struct blkmtd_dev *dev = mtd->priv;
-       struct mtd_erase_region_info *einfo = mtd->eraseregions;
-       int numregions = mtd->numeraseregions;
-       size_t from;
-       u_long len;
-       int err = -EIO;
-       size_t retlen;
-
-       instr->state = MTD_ERASING;
-       from = instr->addr;
-       len = instr->len;
-
-       /* check erase region has valid start and length */
-       DEBUG(2, "blkmtd: erase: dev = `%s' from = 0x%zx len = 0x%lx\n",
-             mtd->name+9, from, len);
-       while(numregions) {
-               DEBUG(3, "blkmtd: checking erase region = 0x%08X size = 0x%X num = 0x%x\n",
-                     einfo->offset, einfo->erasesize, einfo->numblocks);
-               if(from >= einfo->offset
-                  && from < einfo->offset + (einfo->erasesize * einfo->numblocks)) {
-                       if(len == einfo->erasesize
-                          && ( (from - einfo->offset) % einfo->erasesize == 0))
-                               break;
-               }
-               numregions--;
-               einfo++;
-       }
-
-       if(!numregions) {
-               /* Not a valid erase block */
-               err("erase: invalid erase request 0x%lX @ 0x%08zX", len, from);
-               instr->state = MTD_ERASE_FAILED;
-               err = -EIO;
-       }
-
-       if(instr->state != MTD_ERASE_FAILED) {
-               /* do the erase */
-               DEBUG(3, "Doing erase from = %zd len = %ld\n", from, len);
-               err = write_pages(dev, NULL, from, len, &retlen);
-               if(err || retlen != len) {
-                       err("erase failed err = %d", err);
-                       instr->state = MTD_ERASE_FAILED;
-               } else {
-                       instr->state = MTD_ERASE_DONE;
-               }
-       }
-
-       DEBUG(3, "blkmtd: erase: checking callback\n");
-       mtd_erase_callback(instr);
-       DEBUG(2, "blkmtd: erase: finished (err = %d)\n", err);
-       return err;
-}
-
-
-/* read a range of the data via the page cache */
-static int blkmtd_read(struct mtd_info *mtd, loff_t from, size_t len,
-                      size_t *retlen, u_char *buf)
-{
-       struct blkmtd_dev *dev = mtd->priv;
-       int err = 0;
-       int offset;
-       int pagenr, pages;
-       size_t thislen = 0;
-
-       DEBUG(2, "blkmtd: read: dev = `%s' from = %lld len = %zd buf = %p\n",
-             mtd->name+9, from, len, buf);
-
-       if(from > mtd->size)
-               return -EINVAL;
-       if(from + len > mtd->size)
-               len = mtd->size - from;
-
-       pagenr = from >> PAGE_SHIFT;
-       offset = from - (pagenr << PAGE_SHIFT);
-
-       pages = (offset+len+PAGE_SIZE-1) >> PAGE_SHIFT;
-       DEBUG(3, "blkmtd: read: pagenr = %d offset = %d, pages = %d\n",
-             pagenr, offset, pages);
-
-       while(pages) {
-               struct page *page;
-               int cpylen;
-
-               DEBUG(3, "blkmtd: read: looking for page: %d\n", pagenr);
-               page = read_cache_page(dev->blkdev->bd_inode->i_mapping, pagenr, (filler_t *)blkmtd_readpage, dev);
-               if(IS_ERR(page)) {
-                       err = -EIO;
-                       goto readerr;
-               }
-
-               cpylen = (PAGE_SIZE > len) ? len : PAGE_SIZE;
-               if(offset+cpylen > PAGE_SIZE)
-                       cpylen = PAGE_SIZE-offset;
-
-               memcpy(buf + thislen, page_address(page) + offset, cpylen);
-               offset = 0;
-               len -= cpylen;
-               thislen += cpylen;
-               pagenr++;
-               pages--;
-               if(!PageDirty(page))
-                       page_cache_release(page);
-       }
-
- readerr:
-       if(retlen)
-               *retlen = thislen;
-       DEBUG(2, "blkmtd: end read: retlen = %zd, err = %d\n", thislen, err);
-       return err;
-}
-
-
-/* write data to the underlying device */
-static int blkmtd_write(struct mtd_info *mtd, loff_t to, size_t len,
-                       size_t *retlen, const u_char *buf)
-{
-       struct blkmtd_dev *dev = mtd->priv;
-       int err;
-
-       if(!len)
-               return 0;
-
-       DEBUG(2, "blkmtd: write: dev = `%s' to = %lld len = %zd buf = %p\n",
-             mtd->name+9, to, len, buf);
-
-       if(to >= mtd->size) {
-               return -ENOSPC;
-       }
-
-       if(to + len > mtd->size) {
-               len = mtd->size - to;
-       }
-
-       err = write_pages(dev, buf, to, len, retlen);
-       if(err > 0)
-               err = 0;
-       DEBUG(2, "blkmtd: write: end, err = %d\n", err);
-       return err;
-}
-
-
-/* sync the device - wait until the write queue is empty */
-static void blkmtd_sync(struct mtd_info *mtd)
-{
-       /* Currently all writes are synchronous */
-}
-
-
-static void free_device(struct blkmtd_dev *dev)
-{
-       DEBUG(2, "blkmtd: free_device() dev = %p\n", dev);
-       if(dev) {
-               kfree(dev->mtd_info.eraseregions);
-               kfree(dev->mtd_info.name);
-               if(dev->blkdev) {
-                       invalidate_inode_pages(dev->blkdev->bd_inode->i_mapping);
-                       close_bdev_excl(dev->blkdev);
-               }
-               kfree(dev);
-       }
-}
-
-
-/* For a given size and initial erase size, calculate the number
- * and size of each erase region. Goes round the loop twice,
- * once to find out how many regions, then allocates space,
- * then round the loop again to fill it in.
- */
-static struct mtd_erase_region_info *calc_erase_regions(
-       size_t erase_size, size_t total_size, int *regions)
-{
-       struct mtd_erase_region_info *info = NULL;
-
-       DEBUG(2, "calc_erase_regions, es = %zd size = %zd regions = %d\n",
-             erase_size, total_size, *regions);
-       /* Make any user specified erasesize be a power of 2
-          and at least PAGE_SIZE */
-       if(erase_size) {
-               int es = erase_size;
-               erase_size = 1;
-               while(es != 1) {
-                       es >>= 1;
-                       erase_size <<= 1;
-               }
-               if(erase_size < PAGE_SIZE)
-                       erase_size = PAGE_SIZE;
-       } else {
-               erase_size = CONFIG_MTD_BLKDEV_ERASESIZE;
-       }
-
-       *regions = 0;
-
-       do {
-               int tot_size = total_size;
-               int er_size = erase_size;
-               int count = 0, offset = 0, regcnt = 0;
-
-               while(tot_size) {
-                       count = tot_size / er_size;
-                       if(count) {
-                               tot_size = tot_size % er_size;
-                               if(info) {
-                                       DEBUG(2, "adding to erase info off=%d er=%d cnt=%d\n",
-                                             offset, er_size, count);
-                                       (info+regcnt)->offset = offset;
-                                       (info+regcnt)->erasesize = er_size;
-                                       (info+regcnt)->numblocks = count;
-                                       (*regions)++;
-                               }
-                               regcnt++;
-                               offset += (count * er_size);
-                       }
-                       while(er_size > tot_size)
-                               er_size >>= 1;
-               }
-               if(info == NULL) {
-                       info = kmalloc(regcnt * sizeof(struct mtd_erase_region_info), GFP_KERNEL);
-                       if(!info)
-                               break;
-               }
-       } while(!(*regions));
-       DEBUG(2, "calc_erase_regions done, es = %zd size = %zd regions = %d\n",
-             erase_size, total_size, *regions);
-       return info;
-}
-
-
-static struct blkmtd_dev *add_device(char *devname, int readonly, int erase_size)
-{
-       struct block_device *bdev;
-       int mode;
-       struct blkmtd_dev *dev;
-
-       if(!devname)
-               return NULL;
-
-       /* Get a handle on the device */
-
-
-#ifdef MODULE
-       mode = (readonly) ? O_RDONLY : O_RDWR;
-       bdev = open_bdev_excl(devname, mode, NULL);
-#else
-       mode = (readonly) ? FMODE_READ : FMODE_WRITE;
-       bdev = open_by_devnum(name_to_dev_t(devname), mode);
-#endif
-       if(IS_ERR(bdev)) {
-               err("error: cannot open device %s", devname);
-               DEBUG(2, "blkmtd: opening bdev returned %ld\n", PTR_ERR(bdev));
-               return NULL;
-       }
-
-       DEBUG(1, "blkmtd: found a block device major = %d, minor = %d\n",
-             MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
-
-       if(MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
-               err("attempting to use an MTD device as a block device");
-               blkdev_put(bdev);
-               return NULL;
-       }
-
-       dev = kmalloc(sizeof(struct blkmtd_dev), GFP_KERNEL);
-       if(dev == NULL) {
-               blkdev_put(bdev);
-               return NULL;
-       }
-
-       memset(dev, 0, sizeof(struct blkmtd_dev));
-       dev->blkdev = bdev;
-       if(!readonly) {
-               mutex_init(&dev->wrbuf_mutex);
-       }
-
-       dev->mtd_info.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
-
-       /* Setup the MTD structure */
-       /* make the name contain the block device in */
-       dev->mtd_info.name = kmalloc(sizeof("blkmtd: ") + strlen(devname), GFP_KERNEL);
-       if(dev->mtd_info.name == NULL)
-               goto devinit_err;
-
-       sprintf(dev->mtd_info.name, "blkmtd: %s", devname);
-       dev->mtd_info.eraseregions = calc_erase_regions(erase_size, dev->mtd_info.size,
-                                                       &dev->mtd_info.numeraseregions);
-       if(dev->mtd_info.eraseregions == NULL)
-               goto devinit_err;
-
-       dev->mtd_info.erasesize = dev->mtd_info.eraseregions->erasesize;
-       DEBUG(1, "blkmtd: init: found %d erase regions\n",
-             dev->mtd_info.numeraseregions);
-
-       if(readonly) {
-               dev->mtd_info.type = MTD_ROM;
-               dev->mtd_info.flags = MTD_CAP_ROM;
-       } else {
-               dev->mtd_info.type = MTD_RAM;
-               dev->mtd_info.flags = MTD_CAP_RAM;
-               dev->mtd_info.erase = blkmtd_erase;
-               dev->mtd_info.write = blkmtd_write;
-               dev->mtd_info.writev = default_mtd_writev;
-               dev->mtd_info.sync = blkmtd_sync;
-       }
-       dev->mtd_info.read = blkmtd_read;
-       dev->mtd_info.readv = default_mtd_readv;
-       dev->mtd_info.priv = dev;
-       dev->mtd_info.owner = THIS_MODULE;
-
-       list_add(&dev->list, &blkmtd_device_list);
-       if (add_mtd_device(&dev->mtd_info)) {
-               /* Device didnt get added, so free the entry */
-               list_del(&dev->list);
-               goto devinit_err;
-       } else {
-               info("mtd%d: [%s] erase_size = %dKiB %s",
-                    dev->mtd_info.index, dev->mtd_info.name + strlen("blkmtd: "),
-                    dev->mtd_info.erasesize >> 10,
-                    readonly ? "(read-only)" : "");
-       }
-
-       return dev;
-
- devinit_err:
-       free_device(dev);
-       return NULL;
-}
-
-
-/* Cleanup and exit - sync the device and kill of the kernel thread */
-static void __devexit cleanup_blkmtd(void)
-{
-       struct list_head *temp1, *temp2;
-
-       /* Remove the MTD devices */
-       list_for_each_safe(temp1, temp2, &blkmtd_device_list) {
-               struct blkmtd_dev *dev = list_entry(temp1, struct blkmtd_dev,
-                                                   list);
-               blkmtd_sync(&dev->mtd_info);
-               del_mtd_device(&dev->mtd_info);
-               info("mtd%d: [%s] removed", dev->mtd_info.index,
-                    dev->mtd_info.name + strlen("blkmtd: "));
-               list_del(&dev->list);
-               free_device(dev);
-       }
-}
-
-#ifndef MODULE
-
-/* Handle kernel boot params */
-
-
-static int __init param_blkmtd_device(char *str)
-{
-       int i;
-
-       for(i = 0; i < MAX_DEVICES; i++) {
-               device[i] = str;
-               DEBUG(2, "blkmtd: device setup: %d = %s\n", i, device[i]);
-               strsep(&str, ",");
-       }
-       return 1;
-}
-
-
-static int __init param_blkmtd_erasesz(char *str)
-{
-       int i;
-       for(i = 0; i < MAX_DEVICES; i++) {
-               char *val = strsep(&str, ",");
-               if(val)
-                       erasesz[i] = simple_strtoul(val, NULL, 0);
-               DEBUG(2, "blkmtd: erasesz setup: %d = %d\n", i, erasesz[i]);
-       }
-
-       return 1;
-}
-
-
-static int __init param_blkmtd_ro(char *str)
-{
-       int i;
-       for(i = 0; i < MAX_DEVICES; i++) {
-               char *val = strsep(&str, ",");
-               if(val)
-                       ro[i] = simple_strtoul(val, NULL, 0);
-               DEBUG(2, "blkmtd: ro setup: %d = %d\n", i, ro[i]);
-       }
-
-       return 1;
-}
-
-
-static int __init param_blkmtd_sync(char *str)
-{
-       if(str[0] == '1')
-               sync = 1;
-       return 1;
-}
-
-__setup("blkmtd_device=", param_blkmtd_device);
-__setup("blkmtd_erasesz=", param_blkmtd_erasesz);
-__setup("blkmtd_ro=", param_blkmtd_ro);
-__setup("blkmtd_sync=", param_blkmtd_sync);
-
-#endif
-
-
-/* Startup */
-static int __init init_blkmtd(void)
-{
-       int i;
-
-       info("version " VERSION);
-       /* Check args - device[0] is the bare minimum*/
-       if(!device[0]) {
-               err("error: missing `device' name\n");
-               return -EINVAL;
-       }
-
-       for(i = 0; i < MAX_DEVICES; i++)
-               add_device(device[i], ro[i], erasesz[i] << 10);
-
-       if(list_empty(&blkmtd_device_list))
-               return -EINVAL;
-
-       return 0;
-}
-
-module_init(init_blkmtd);
-module_exit(cleanup_blkmtd);