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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [armnommu/] [drivers/] [block/] [rd.c] - Rev 199
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/* * ramdisk.c - Multiple ramdisk driver - gzip-loading version - v. 0.8 beta. * * (C) Chad Page, Theodore Ts'o, et. al, 1995. * * This ramdisk 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 * ramdisk data. This makes it possible to dynamically allocate the ramdisk * 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 ramdisk 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 ramdisk interface. Theodore * Ts'o rewrote it so that both the compressed ramdisk loader and the * kernel decompressor uses the same inflate.c codebase. The ramdisk * loader now also loads into a dynamic (buffer cache based) ramdisk, * not the old static ramdisk. Support for the old static ramdisk 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 ramdisk is rmmod'ed, free the protected buffers * Default ramdisk size changed to 2.88MB * * Added initrd: Werner Almesberger & Hans Lermen, Feb '96 * * 4/25/96 : Made ramdisk size a parameter (default is now 4MB) * - Chad Page */ #include <linux/config.h> #include <linux/sched.h> #include <linux/minix_fs.h> #include <linux/ext2_fs.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/malloc.h> #include <linux/ioctl.h> #include <linux/fd.h> #include <linux/module.h> #include <asm/system.h> #include <asm/segment.h> extern void wait_for_keypress(void); /* * 35 has been officially registered as the RAMDISK major number, but * so is the original MAJOR number of 1. We're using 1 in * include/linux/major.h for now */ #define MAJOR_NR RAMDISK_MAJOR #include <linux/blk.h> /* The ramdisk size is now a parameter */ #define NUM_RAMDISKS 16 /* This cannot be overridden (yet) */ #ifndef MODULE /* We don't have to load ramdisks or gunzip them in a module... */ #define RD_LOADER #define BUILD_CRAMDISK void rd_load(void); static int crd_load(struct file *fp, struct file *outfp); #ifdef CONFIG_BLK_DEV_INITRD static int initrd_users = 0; #endif #endif /* Various static variables go here... mostly used within the ramdisk code only. */ static int rd_length[NUM_RAMDISKS]; static int rd_blocksizes[NUM_RAMDISKS]; /* * Parameters for the boot-loading of the ramdisk. These are set by * init/main.c (from arguments to the kernel command line) or from the * architecture-specific setup routine (from the stored bootsector * information). */ int rd_size = 4096; /* Size of the ramdisks */ #ifndef MODULE int rd_doload = 0; /* 1 = load ramdisk, 0 = don't load */ int rd_prompt = 1; /* 1 = prompt for ramdisk, 0 = don't prompt */ int rd_image_start = 0; /* starting block # of image */ #ifdef CONFIG_BLK_DEV_INITRD unsigned long initrd_start,initrd_end; int mount_initrd = 1; /* zero if initrd should not be mounted */ #endif #endif /* * 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... * */ static void rd_request(void) { unsigned int minor; int offset, len; repeat: INIT_REQUEST; minor = MINOR(CURRENT->rq_dev); if (minor >= NUM_RAMDISKS) { end_request(0); goto repeat; } offset = CURRENT->sector << 9; len = CURRENT->current_nr_sectors << 9; if ((offset + len) > rd_length[minor]) { end_request(0); goto repeat; } /* * If we're reading, fill the buffer with 0's. This is okay since * we're using protected buffers which should never get freed... * * If we're writing, we protect the buffer. */ if (CURRENT->cmd == READ) memset(CURRENT->buffer, 0, len); else set_bit(BH_Protected, &CURRENT->bh->b_state); end_request(1); goto repeat; } static int rd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int err; if (!inode || !inode->i_rdev) return -EINVAL; switch (cmd) { case BLKFLSBUF: if (!suser()) return -EACCES; invalidate_buffers(inode->i_rdev); break; case BLKGETSIZE: /* Return device size */ if (!arg) return -EINVAL; err = verify_area(VERIFY_WRITE, (long *) arg, sizeof(long)); if (err) return err; put_user(rd_length[MINOR(inode->i_rdev)] / 512, (long *) arg); return 0; default: break; }; return 0; } #ifdef CONFIG_BLK_DEV_INITRD static int initrd_read(struct inode *inode,struct file *file,char *buf, int count) { int left; left = initrd_end-initrd_start-file->f_pos; if (count > left) count = left; if (count <= 0) return 0; memcpy_tofs(buf,(char *) initrd_start+file->f_pos,count); file->f_pos += count; return count; } static void initrd_release(struct inode *inode,struct file *file) { unsigned long i; if (--initrd_users) return; for (i = initrd_start; i < initrd_end; i += PAGE_SIZE) free_page(i); initrd_start = 0; } static struct file_operations initrd_fops = { NULL, /* lseek */ initrd_read, /* read */ NULL, /* write */ NULL, /* readdir */ NULL, /* select */ NULL, /* ioctl */ NULL, /* mmap */ NULL, /* open */ initrd_release, /* release */ NULL /* fsync */ }; #endif static int rd_open(struct inode * inode, struct file * filp) { #ifdef CONFIG_BLK_DEV_INITRD if (DEVICE_NR(inode->i_rdev) == INITRD_MINOR) { if (!initrd_start) return -ENODEV; initrd_users++; filp->f_op = &initrd_fops; return 0; } #endif if (DEVICE_NR(inode->i_rdev) >= NUM_RAMDISKS) return -ENXIO; MOD_INC_USE_COUNT; return 0; } #ifdef MODULE static void rd_release(struct inode * inode, struct file * filp) { MOD_DEC_USE_COUNT; } #endif static struct file_operations fd_fops = { NULL, /* lseek - default */ block_read, /* read - block dev read */ block_write, /* write - block dev write */ NULL, /* readdir - not here! */ NULL, /* select */ rd_ioctl, /* ioctl */ NULL, /* mmap */ rd_open, /* open */ #ifndef MODULE NULL, /* no special release code... */ #else rd_release, /* module needs to decrement use count */ #endif block_fsync /* fsync */ }; /* This is the registration and initialization section of the ramdisk driver */ int rd_init(void) { int i; if (register_blkdev(MAJOR_NR, "ramdisk", &fd_fops)) { printk("RAMDISK: Could not get major %d", MAJOR_NR); return -EIO; } blk_dev[MAJOR_NR].request_fn = &rd_request; for (i = 0; i < NUM_RAMDISKS; i++) { rd_length[i] = (rd_size * 1024); rd_blocksizes[i] = 1024; } blksize_size[MAJOR_NR] = rd_blocksizes; printk("Ramdisk driver initialized : %d ramdisks of %dK size\n", NUM_RAMDISKS, rd_size); return 0; } /* loadable module support */ #ifdef MODULE int init_module(void) { int error = rd_init(); if (!error) printk(KERN_INFO "RAMDISK: Loaded as module.\n"); return error; } /* Before freeing the module, invalidate all of the protected buffers! */ void cleanup_module(void) { int i; for (i = 0 ; i < NUM_RAMDISKS; i++) invalidate_buffers(MKDEV(MAJOR_NR, i)); unregister_blkdev( MAJOR_NR, "ramdisk" ); blk_dev[MAJOR_NR].request_fn = 0; } #endif /* MODULE */ /* End of non-loading portions of the ramdisk driver */ #ifdef RD_LOADER /* * This routine tries to a ramdisk image to load, and returns the * number of blocks to read for a non-compressed image, 0 if the image * is a compressed image, and -1 if an image with the right magic * numbers could not be found. * * We currently check for the following magic numbers: * minix * ext2 * gzip */ int identify_ramdisk_image(kdev_t device, struct file *fp, int start_block) { const int size = 512; struct minix_super_block *minixsb; struct ext2_super_block *ext2sb; int nblocks = -1; int max_blocks; unsigned char *buf; buf = kmalloc(size, GFP_KERNEL); if (buf == 0) return -1; minixsb = (struct minix_super_block *) buf; ext2sb = (struct ext2_super_block *) buf; memset(buf, 0xe5, size); /* * Read block 0 to test for gzipped kernel */ if (fp->f_op->lseek) fp->f_op->lseek(fp->f_inode, fp, start_block * BLOCK_SIZE, 0); fp->f_pos = start_block * BLOCK_SIZE; fp->f_op->read(fp->f_inode, fp, buf, size); /* * If it matches the gzip magic numbers, return -1 */ if (buf[0] == 037 && ((buf[1] == 0213) || (buf[1] == 0236))) { printk(KERN_NOTICE "RAMDISK: Compressed image found at block %d\n", start_block); nblocks = 0; goto done; } /* * Read block 1 to test for minix and ext2 superblock */ if (fp->f_op->lseek) fp->f_op->lseek(fp->f_inode, fp, (start_block+1) * BLOCK_SIZE, 0); fp->f_pos = (start_block+1) * BLOCK_SIZE; fp->f_op->read(fp->f_inode, fp, buf, size); /* Try minix */ if (minixsb->s_magic == MINIX_SUPER_MAGIC || minixsb->s_magic == MINIX_SUPER_MAGIC2) { printk(KERN_NOTICE "RAMDISK: Minix filesystem found at block %d\n", start_block); nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; goto done; } /* Try ext2 */ if (ext2sb->s_magic == EXT2_SUPER_MAGIC) { printk(KERN_NOTICE "RAMDISK: Ext2 filesystem found at block %d\n", start_block); nblocks = ext2sb->s_blocks_count; goto done; } printk(KERN_NOTICE "RAMDISK: Couldn't find valid ramdisk image starting at %d.\n", start_block); done: if (fp->f_op->lseek) fp->f_op->lseek(fp->f_inode, fp, start_block * BLOCK_SIZE, 0); fp->f_pos = start_block * BLOCK_SIZE; if ((nblocks > 0) && blk_size[MAJOR(device)]) { max_blocks = blk_size[MAJOR(device)][MINOR(device)]; max_blocks -= start_block; if (nblocks > max_blocks) { printk(KERN_NOTICE "RAMDISK: Restricting filesystem size " "from %d to %d blocks.\n", nblocks, max_blocks); nblocks = max_blocks; } } kfree(buf); return nblocks; } /* * This routine loads in the ramdisk image. */ static void rd_load_image(kdev_t device,int offset, int unit) { struct inode inode, out_inode; struct file infile, outfile; unsigned short fs; kdev_t ram_device; int nblocks, i; char *buf; unsigned short rotate = 0; char rotator[4] = { '|' , '/' , '-' , '\\' }; ram_device = MKDEV(MAJOR_NR, unit); memset(&infile, 0, sizeof(infile)); memset(&inode, 0, sizeof(inode)); inode.i_rdev = device; infile.f_mode = 1; /* read only */ infile.f_inode = &inode; memset(&outfile, 0, sizeof(outfile)); memset(&out_inode, 0, sizeof(out_inode)); out_inode.i_rdev = ram_device; outfile.f_mode = 3; /* read/write */ outfile.f_inode = &out_inode; if (blkdev_open(&inode, &infile) != 0) return; if (blkdev_open(&out_inode, &outfile) != 0) return; fs = get_fs(); set_fs(KERNEL_DS); nblocks = identify_ramdisk_image(device, &infile, offset); if (nblocks < 0) goto done; if (nblocks == 0) { #ifdef BUILD_CRAMDISK if (crd_load(&infile, &outfile) == 0) goto successful_load; #else printk(KERN_NOTICE "RAMDISK: Kernel does not support compressed " "ramdisk images\n"); #endif goto done; } if (nblocks > (rd_length[0] >> BLOCK_SIZE_BITS)) { printk("RAMDISK: image too big! (%d/%d blocks)\n", nblocks, rd_length[0] >> BLOCK_SIZE_BITS); goto done; } /* * OK, time to copy in the data */ buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); if (buf == 0) { printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); goto done; } printk(KERN_NOTICE "RAMDISK: Loading %d blocks into ram disk... ", nblocks); for (i=0; i < nblocks; i++) { infile.f_op->read(infile.f_inode, &infile, buf, BLOCK_SIZE); outfile.f_op->write(outfile.f_inode, &outfile, buf, BLOCK_SIZE); if (!(i % 16)) { printk("%c\b", rotator[rotate & 0x3]); rotate++; } } printk("done.\n"); kfree(buf); successful_load: invalidate_buffers(device); ROOT_DEV = MKDEV(MAJOR_NR,unit); done: if (infile.f_op->release) infile.f_op->release(&inode, &infile); set_fs(fs); } static void rd_load_disk(int n) { #ifdef CONFIG_BLK_DEV_INITRD extern kdev_t real_root_dev; #endif if (rd_doload == 0) return; if (MAJOR(ROOT_DEV) != FLOPPY_MAJOR #ifdef CONFIG_BLK_DEV_INITRD && MAJOR(real_root_dev) != FLOPPY_MAJOR #endif ) return; if (rd_prompt) { #ifdef CONFIG_BLK_DEV_FD floppy_eject(); #endif printk(KERN_NOTICE "VFS: Insert root floppy disk to be loaded into ramdisk and press ENTER\n"); wait_for_keypress(); } rd_load_image(ROOT_DEV,rd_image_start,n); } void rd_load(void) { rd_load_disk(0); } void rd_load_secondary(void) { rd_load_disk(1); } #ifdef CONFIG_BLK_DEV_INITRD void initrd_load(void) { rd_load_image(MKDEV(MAJOR_NR, INITRD_MINOR),0,0); } #endif #endif /* RD_LOADER */ #ifdef BUILD_CRAMDISK /* * gzip declarations */ #define OF(args) args #define memzero(s, n) memset ((s), 0, (n)) typedef unsigned char uch; typedef unsigned short ush; typedef unsigned long ulg; #define INBUFSIZ 4096 #define WSIZE 0x8000 /* window size--must be a power of two, and */ /* at least 32K for zip's deflate method */ static uch *inbuf; static uch *window; static unsigned insize = 0; /* valid bytes in inbuf */ static unsigned inptr = 0; /* index of next byte to be processed in inbuf */ static unsigned outcnt = 0; /* bytes in output buffer */ static int exit_code = 0; static long bytes_out = 0; static struct file *crd_infp, *crd_outfp; #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf()) /* Diagnostic functions (stubbed out) */ #define Assert(cond,msg) #define Trace(x) #define Tracev(x) #define Tracevv(x) #define Tracec(c,x) #define Tracecv(c,x) #define STATIC static static int fill_inbuf(void); static void flush_window(void); static void *malloc(int size); static void free(void *where); static void error(char *m); static void gzip_mark(void **); static void gzip_release(void **); #include "../../../../lib/inflate.c" static void *malloc(int size) { return kmalloc(size, GFP_KERNEL); } static void free(void *where) { kfree(where); } static void gzip_mark(void **ptr) { } static void gzip_release(void **ptr) { } /* =========================================================================== * Fill the input buffer. This is called only when the buffer is empty * and at least one byte is really needed. */ static int fill_inbuf() { if (exit_code) return -1; insize = crd_infp->f_op->read(crd_infp->f_inode, crd_infp, inbuf, INBUFSIZ); if (insize == 0) return -1; inptr = 1; return inbuf[0]; } /* =========================================================================== * Write the output window window[0..outcnt-1] and update crc and bytes_out. * (Used for the decompressed data only.) */ static void flush_window() { ulg c = crc; /* temporary variable */ unsigned n; uch *in, ch; crd_outfp->f_op->write(crd_outfp->f_inode, crd_outfp, window, outcnt); in = window; for (n = 0; n < outcnt; n++) { ch = *in++; c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); } crc = c; bytes_out += (ulg)outcnt; outcnt = 0; } static void error(char *x) { printk(KERN_ERR "%s", x); exit_code = 1; } static int crd_load(struct file * fp, struct file *outfp) { int result; insize = 0; /* valid bytes in inbuf */ inptr = 0; /* index of next byte to be processed in inbuf */ outcnt = 0; /* bytes in output buffer */ exit_code = 0; bytes_out = 0; crc = 0xFFFFFFFF; crd_infp = fp; crd_outfp = outfp; inbuf = kmalloc(INBUFSIZ, GFP_KERNEL); if (inbuf == 0) { printk(KERN_ERR "RAMDISK: Couldn't allocate gzip buffer\n"); return -1; } window = kmalloc(WSIZE, GFP_KERNEL); if (window == 0) { printk(KERN_ERR "RAMDISK: Couldn't allocate gzip window\n"); kfree(inbuf); return -1; } makecrc(); result = gunzip(); kfree(inbuf); kfree(window); return result; } #endif /* BUILD_CRAMDISK */
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