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-rw-r--r--drivers/block/rd.c537
1 files changed, 0 insertions, 537 deletions
diff --git a/drivers/block/rd.c b/drivers/block/rd.c
deleted file mode 100644
index 06e23be..0000000
--- a/drivers/block/rd.c
+++ /dev/null
@@ -1,537 +0,0 @@
-/*
- * ramdisk.c - Multiple RAM disk driver - gzip-loading version - v. 0.8 beta.
- *
- * (C) Chad Page, Theodore Ts'o, et. al, 1995.
- *
- * This RAM disk is designed to have filesystems created on it and mounted
- * just like a regular floppy disk.
- *
- * It also does something suggested by Linus: use the buffer cache as the
- * RAM disk data. This makes it possible to dynamically allocate the RAM disk
- * buffer - with some consequences I have to deal with as I write this.
- *
- * This code is based on the original ramdisk.c, written mostly by
- * Theodore Ts'o (TYT) in 1991. The code was largely rewritten by
- * Chad Page to use the buffer cache to store the RAM disk data in
- * 1995; Theodore then took over the driver again, and cleaned it up
- * for inclusion in the mainline kernel.
- *
- * The original CRAMDISK code was written by Richard Lyons, and
- * adapted by Chad Page to use the new RAM disk interface. Theodore
- * Ts'o rewrote it so that both the compressed RAM disk loader and the
- * kernel decompressor uses the same inflate.c codebase. The RAM disk
- * loader now also loads into a dynamic (buffer cache based) RAM disk,
- * not the old static RAM disk. Support for the old static RAM disk has
- * been completely removed.
- *
- * Loadable module support added by Tom Dyas.
- *
- * Further cleanups by Chad Page (page0588@sundance.sjsu.edu):
- * Cosmetic changes in #ifdef MODULE, code movement, etc.
- * When the RAM disk module is removed, free the protected buffers
- * Default RAM disk size changed to 2.88 MB
- *
- * Added initrd: Werner Almesberger & Hans Lermen, Feb '96
- *
- * 4/25/96 : Made RAM disk size a parameter (default is now 4 MB)
- * - Chad Page
- *
- * Add support for fs images split across >1 disk, Paul Gortmaker, Mar '98
- *
- * Make block size and block size shift for RAM disks a global macro
- * and set blk_size for -ENOSPC, Werner Fink <werner@suse.de>, Apr '99
- */
-
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <asm/atomic.h>
-#include <linux/bio.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/init.h>
-#include <linux/pagemap.h>
-#include <linux/blkdev.h>
-#include <linux/genhd.h>
-#include <linux/buffer_head.h> /* for invalidate_bdev() */
-#include <linux/backing-dev.h>
-#include <linux/blkpg.h>
-#include <linux/writeback.h>
-#include <linux/log2.h>
-
-#include <asm/uaccess.h>
-
-/* Various static variables go here. Most are used only in the RAM disk code.
- */
-
-static struct gendisk *rd_disks[CONFIG_BLK_DEV_RAM_COUNT];
-static struct block_device *rd_bdev[CONFIG_BLK_DEV_RAM_COUNT];/* Protected device data */
-static struct request_queue *rd_queue[CONFIG_BLK_DEV_RAM_COUNT];
-
-/*
- * Parameters for the boot-loading of the RAM disk. These are set by
- * init/main.c (from arguments to the kernel command line) or from the
- * architecture-specific setup routine (from the stored boot sector
- * information).
- */
-int rd_size = CONFIG_BLK_DEV_RAM_SIZE; /* Size of the RAM disks */
-/*
- * It would be very desirable to have a soft-blocksize (that in the case
- * of the ramdisk driver is also the hardblocksize ;) of PAGE_SIZE because
- * doing that we'll achieve a far better MM footprint. Using a rd_blocksize of
- * BLOCK_SIZE in the worst case we'll make PAGE_SIZE/BLOCK_SIZE buffer-pages
- * unfreeable. With a rd_blocksize of PAGE_SIZE instead we are sure that only
- * 1 page will be protected. Depending on the size of the ramdisk you
- * may want to change the ramdisk blocksize to achieve a better or worse MM
- * behaviour. The default is still BLOCK_SIZE (needed by rd_load_image that
- * supposes the filesystem in the image uses a BLOCK_SIZE blocksize).
- */
-static int rd_blocksize = CONFIG_BLK_DEV_RAM_BLOCKSIZE;
-
-/*
- * Copyright (C) 2000 Linus Torvalds.
- * 2000 Transmeta Corp.
- * aops copied from ramfs.
- */
-
-/*
- * If a ramdisk page has buffers, some may be uptodate and some may be not.
- * To bring the page uptodate we zero out the non-uptodate buffers. The
- * page must be locked.
- */
-static void make_page_uptodate(struct page *page)
-{
- if (page_has_buffers(page)) {
- struct buffer_head *bh = page_buffers(page);
- struct buffer_head *head = bh;
-
- do {
- if (!buffer_uptodate(bh)) {
- memset(bh->b_data, 0, bh->b_size);
- /*
- * akpm: I'm totally undecided about this. The
- * buffer has just been magically brought "up to
- * date", but nobody should want to be reading
- * it anyway, because it hasn't been used for
- * anything yet. It is still in a "not read
- * from disk yet" state.
- *
- * But non-uptodate buffers against an uptodate
- * page are against the rules. So do it anyway.
- */
- set_buffer_uptodate(bh);
- }
- } while ((bh = bh->b_this_page) != head);
- } else {
- memset(page_address(page), 0, PAGE_CACHE_SIZE);
- }
- flush_dcache_page(page);
- SetPageUptodate(page);
-}
-
-static int ramdisk_readpage(struct file *file, struct page *page)
-{
- if (!PageUptodate(page))
- make_page_uptodate(page);
- unlock_page(page);
- return 0;
-}
-
-static int ramdisk_prepare_write(struct file *file, struct page *page,
- unsigned offset, unsigned to)
-{
- if (!PageUptodate(page))
- make_page_uptodate(page);
- return 0;
-}
-
-static int ramdisk_commit_write(struct file *file, struct page *page,
- unsigned offset, unsigned to)
-{
- set_page_dirty(page);
- return 0;
-}
-
-/*
- * ->writepage to the blockdev's mapping has to redirty the page so that the
- * VM doesn't go and steal it. We return AOP_WRITEPAGE_ACTIVATE so that the VM
- * won't try to (pointlessly) write the page again for a while.
- *
- * Really, these pages should not be on the LRU at all.
- */
-static int ramdisk_writepage(struct page *page, struct writeback_control *wbc)
-{
- if (!PageUptodate(page))
- make_page_uptodate(page);
- SetPageDirty(page);
- if (wbc->for_reclaim)
- return AOP_WRITEPAGE_ACTIVATE;
- unlock_page(page);
- return 0;
-}
-
-/*
- * This is a little speedup thing: short-circuit attempts to write back the
- * ramdisk blockdev inode to its non-existent backing store.
- */
-static int ramdisk_writepages(struct address_space *mapping,
- struct writeback_control *wbc)
-{
- return 0;
-}
-
-/*
- * ramdisk blockdev pages have their own ->set_page_dirty() because we don't
- * want them to contribute to dirty memory accounting.
- */
-static int ramdisk_set_page_dirty(struct page *page)
-{
- if (!TestSetPageDirty(page))
- return 1;
- return 0;
-}
-
-/*
- * releasepage is called by pagevec_strip/try_to_release_page if
- * buffers_heads_over_limit is true. Without a releasepage function
- * try_to_free_buffers is called instead. That can unset the dirty
- * bit of our ram disk pages, which will be eventually freed, even
- * if the page is still in use.
- */
-static int ramdisk_releasepage(struct page *page, gfp_t dummy)
-{
- return 0;
-}
-
-static const struct address_space_operations ramdisk_aops = {
- .readpage = ramdisk_readpage,
- .prepare_write = ramdisk_prepare_write,
- .commit_write = ramdisk_commit_write,
- .writepage = ramdisk_writepage,
- .set_page_dirty = ramdisk_set_page_dirty,
- .writepages = ramdisk_writepages,
- .releasepage = ramdisk_releasepage,
-};
-
-static int rd_blkdev_pagecache_IO(int rw, struct bio_vec *vec, sector_t sector,
- struct address_space *mapping)
-{
- pgoff_t index = sector >> (PAGE_CACHE_SHIFT - 9);
- unsigned int vec_offset = vec->bv_offset;
- int offset = (sector << 9) & ~PAGE_CACHE_MASK;
- int size = vec->bv_len;
- int err = 0;
-
- do {
- int count;
- struct page *page;
- char *src;
- char *dst;
-
- count = PAGE_CACHE_SIZE - offset;
- if (count > size)
- count = size;
- size -= count;
-
- page = grab_cache_page(mapping, index);
- if (!page) {
- err = -ENOMEM;
- goto out;
- }
-
- if (!PageUptodate(page))
- make_page_uptodate(page);
-
- index++;
-
- if (rw == READ) {
- src = kmap_atomic(page, KM_USER0) + offset;
- dst = kmap_atomic(vec->bv_page, KM_USER1) + vec_offset;
- } else {
- src = kmap_atomic(vec->bv_page, KM_USER0) + vec_offset;
- dst = kmap_atomic(page, KM_USER1) + offset;
- }
- offset = 0;
- vec_offset += count;
-
- memcpy(dst, src, count);
-
- kunmap_atomic(src, KM_USER0);
- kunmap_atomic(dst, KM_USER1);
-
- if (rw == READ)
- flush_dcache_page(vec->bv_page);
- else
- set_page_dirty(page);
- unlock_page(page);
- put_page(page);
- } while (size);
-
- out:
- return err;
-}
-
-/*
- * Basically, my strategy here is to set up a buffer-head which can't be
- * deleted, and make that my Ramdisk. If the request is outside of the
- * allocated size, we must get rid of it...
- *
- * 19-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Added devfs support
- *
- */
-static int rd_make_request(struct request_queue *q, struct bio *bio)
-{
- struct block_device *bdev = bio->bi_bdev;
- struct address_space * mapping = bdev->bd_inode->i_mapping;
- sector_t sector = bio->bi_sector;
- unsigned long len = bio->bi_size >> 9;
- int rw = bio_data_dir(bio);
- struct bio_vec *bvec;
- int ret = 0, i;
-
- if (sector + len > get_capacity(bdev->bd_disk))
- goto fail;
-
- if (rw==READA)
- rw=READ;
-
- bio_for_each_segment(bvec, bio, i) {
- ret |= rd_blkdev_pagecache_IO(rw, bvec, sector, mapping);
- sector += bvec->bv_len >> 9;
- }
- if (ret)
- goto fail;
-
- bio_endio(bio, 0);
- return 0;
-fail:
- bio_io_error(bio);
- return 0;
-}
-
-static int rd_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- int error;
- struct block_device *bdev = inode->i_bdev;
-
- if (cmd != BLKFLSBUF)
- return -ENOTTY;
-
- /*
- * special: we want to release the ramdisk memory, it's not like with
- * the other blockdevices where this ioctl only flushes away the buffer
- * cache
- */
- error = -EBUSY;
- mutex_lock(&bdev->bd_mutex);
- if (bdev->bd_openers <= 2) {
- truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
- error = 0;
- }
- mutex_unlock(&bdev->bd_mutex);
- return error;
-}
-
-/*
- * This is the backing_dev_info for the blockdev inode itself. It doesn't need
- * writeback and it does not contribute to dirty memory accounting.
- */
-static struct backing_dev_info rd_backing_dev_info = {
- .ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK | BDI_CAP_MAP_COPY,
- .unplug_io_fn = default_unplug_io_fn,
-};
-
-/*
- * This is the backing_dev_info for the files which live atop the ramdisk
- * "device". These files do need writeback and they do contribute to dirty
- * memory accounting.
- */
-static struct backing_dev_info rd_file_backing_dev_info = {
- .ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_MAP_COPY, /* Does contribute to dirty memory */
- .unplug_io_fn = default_unplug_io_fn,
-};
-
-static int rd_open(struct inode *inode, struct file *filp)
-{
- unsigned unit = iminor(inode);
-
- if (rd_bdev[unit] == NULL) {
- struct block_device *bdev = inode->i_bdev;
- struct address_space *mapping;
- unsigned bsize;
- gfp_t gfp_mask;
-
- inode = igrab(bdev->bd_inode);
- rd_bdev[unit] = bdev;
- bdev->bd_openers++;
- bsize = bdev_hardsect_size(bdev);
- bdev->bd_block_size = bsize;
- inode->i_blkbits = blksize_bits(bsize);
- inode->i_size = get_capacity(bdev->bd_disk)<<9;
-
- mapping = inode->i_mapping;
- mapping->a_ops = &ramdisk_aops;
- mapping->backing_dev_info = &rd_backing_dev_info;
- bdev->bd_inode_backing_dev_info = &rd_file_backing_dev_info;
-
- /*
- * Deep badness. rd_blkdev_pagecache_IO() needs to allocate
- * pagecache pages within a request_fn. We cannot recur back
- * into the filesystem which is mounted atop the ramdisk, because
- * that would deadlock on fs locks. And we really don't want
- * to reenter rd_blkdev_pagecache_IO when we're already within
- * that function.
- *
- * So we turn off __GFP_FS and __GFP_IO.
- *
- * And to give this thing a hope of working, turn on __GFP_HIGH.
- * Hopefully, there's enough regular memory allocation going on
- * for the page allocator emergency pools to keep the ramdisk
- * driver happy.
- */
- gfp_mask = mapping_gfp_mask(mapping);
- gfp_mask &= ~(__GFP_FS|__GFP_IO);
- gfp_mask |= __GFP_HIGH;
- mapping_set_gfp_mask(mapping, gfp_mask);
- }
-
- return 0;
-}
-
-static struct block_device_operations rd_bd_op = {
- .owner = THIS_MODULE,
- .open = rd_open,
- .ioctl = rd_ioctl,
-};
-
-/*
- * Before freeing the module, invalidate all of the protected buffers!
- */
-static void __exit rd_cleanup(void)
-{
- int i;
-
- for (i = 0; i < CONFIG_BLK_DEV_RAM_COUNT; i++) {
- struct block_device *bdev = rd_bdev[i];
- rd_bdev[i] = NULL;
- if (bdev) {
- invalidate_bdev(bdev);
- blkdev_put(bdev);
- }
- del_gendisk(rd_disks[i]);
- put_disk(rd_disks[i]);
- blk_cleanup_queue(rd_queue[i]);
- }
- unregister_blkdev(RAMDISK_MAJOR, "ramdisk");
-
- bdi_destroy(&rd_file_backing_dev_info);
- bdi_destroy(&rd_backing_dev_info);
-}
-
-/*
- * This is the registration and initialization section of the RAM disk driver
- */
-static int __init rd_init(void)
-{
- int i;
- int err;
-
- err = bdi_init(&rd_backing_dev_info);
- if (err)
- goto out2;
-
- err = bdi_init(&rd_file_backing_dev_info);
- if (err) {
- bdi_destroy(&rd_backing_dev_info);
- goto out2;
- }
-
- err = -ENOMEM;
-
- if (rd_blocksize > PAGE_SIZE || rd_blocksize < 512 ||
- !is_power_of_2(rd_blocksize)) {
- printk("RAMDISK: wrong blocksize %d, reverting to defaults\n",
- rd_blocksize);
- rd_blocksize = BLOCK_SIZE;
- }
-
- for (i = 0; i < CONFIG_BLK_DEV_RAM_COUNT; i++) {
- rd_disks[i] = alloc_disk(1);
- if (!rd_disks[i])
- goto out;
-
- rd_queue[i] = blk_alloc_queue(GFP_KERNEL);
- if (!rd_queue[i]) {
- put_disk(rd_disks[i]);
- goto out;
- }
- }
-
- if (register_blkdev(RAMDISK_MAJOR, "ramdisk")) {
- err = -EIO;
- goto out;
- }
-
- for (i = 0; i < CONFIG_BLK_DEV_RAM_COUNT; i++) {
- struct gendisk *disk = rd_disks[i];
-
- blk_queue_make_request(rd_queue[i], &rd_make_request);
- blk_queue_hardsect_size(rd_queue[i], rd_blocksize);
-
- /* rd_size is given in kB */
- disk->major = RAMDISK_MAJOR;
- disk->first_minor = i;
- disk->fops = &rd_bd_op;
- disk->queue = rd_queue[i];
- disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
- sprintf(disk->disk_name, "ram%d", i);
- set_capacity(disk, rd_size * 2);
- add_disk(rd_disks[i]);
- }
-
- /* rd_size is given in kB */
- printk("RAMDISK driver initialized: "
- "%d RAM disks of %dK size %d blocksize\n",
- CONFIG_BLK_DEV_RAM_COUNT, rd_size, rd_blocksize);
-
- return 0;
-out:
- while (i--) {
- put_disk(rd_disks[i]);
- blk_cleanup_queue(rd_queue[i]);
- }
- bdi_destroy(&rd_backing_dev_info);
- bdi_destroy(&rd_file_backing_dev_info);
-out2:
- return err;
-}
-
-module_init(rd_init);
-module_exit(rd_cleanup);
-
-/* options - nonmodular */
-#ifndef MODULE
-static int __init ramdisk_size(char *str)
-{
- rd_size = simple_strtol(str,NULL,0);
- return 1;
-}
-static int __init ramdisk_blocksize(char *str)
-{
- rd_blocksize = simple_strtol(str,NULL,0);
- return 1;
-}
-__setup("ramdisk_size=", ramdisk_size);
-__setup("ramdisk_blocksize=", ramdisk_blocksize);
-#endif
-
-/* options - modular */
-module_param(rd_size, int, 0);
-MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");
-module_param(rd_blocksize, int, 0);
-MODULE_PARM_DESC(rd_blocksize, "Blocksize of each RAM disk in bytes.");
-MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
-
-MODULE_LICENSE("GPL");
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