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/*
* compressed_loop.c: Read-only compressed loop blockdevice
* hacked up by Rusty in 1999, extended and maintained by Klaus Knopper
*
* A cloop file looks like this:
* [32-bit uncompressed block size: network order]
* [32-bit number of blocks (n_blocks): network order]
* [64-bit file offsets of start of blocks: network order]
* ...
* (n_blocks + 1).
* n_blocks consisting of:
* [compressed block]
*
* Every version greatly inspired by code seen in loop.c
* by Theodore Ts'o, 3/29/93.
*
* Copyright 1999-2009 by Paul `Rusty' Russell & Klaus Knopper.
* Redistribution of this file is permitted under the GNU Public License.
*
*/
#define CLOOP_NAME "cloop"
#define CLOOP_VERSION "3.14"
#define CLOOP_MAX 8
#ifndef KBUILD_MODNAME
#define KBUILD_MODNAME cloop
#endif
#ifndef KBUILD_BASENAME
#define KBUILD_BASENAME cloop
#endif
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/major.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <asm/div64.h> /* do_div() for 64bit division */
#include <asm/uaccess.h>
#include <asm/byteorder.h>
/* Use zlib_inflate from lib/zlib_inflate */
#include <linux/zutil.h>
#include <linux/loop.h>
#include <linux/kthread.h>
#include <linux/compat.h>
#include "cloop.h"
/* New License scheme */
#ifdef MODULE_LICENSE
MODULE_LICENSE("GPL");
#endif
#ifdef MODULE_AUTHOR
MODULE_AUTHOR("Klaus Knopper (current maintainer), Paul Russel (initial Kernel 2.2 version)");
#endif
#ifdef MODULE_DESCRIPTION
MODULE_DESCRIPTION("Transparently decompressing loopback block device");
#endif
#ifndef MIN
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#endif
#ifndef MAX
#define MAX(x,y) ((x) > (y) ? (x) : (y))
#endif
/* Use experimental major for now */
#define MAJOR_NR 240
/* #define DEVICE_NAME CLOOP_NAME */
/* #define DEVICE_NR(device) (MINOR(device)) */
/* #define DEVICE_ON(device) */
/* #define DEVICE_OFF(device) */
/* #define DEVICE_NO_RANDOM */
/* #define TIMEOUT_VALUE (6 * HZ) */
#include <linux/blkdev.h>
#include <linux/buffer_head.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, x...)
#endif
/* One file can be opened at module insertion time */
/* insmod cloop file=/path/to/file */
static char *file=NULL;
static unsigned int preload=0;
static unsigned int cloop_max=CLOOP_MAX;
module_param(file, charp, 0);
module_param(preload, uint, 0);
module_param(cloop_max, uint, 0);
MODULE_PARM_DESC(file, "Initial cloop image file (full path) for /dev/cloop");
MODULE_PARM_DESC(preload, "Preload n blocks of cloop data into memory");
MODULE_PARM_DESC(cloop_max, "Maximum number of cloop devices (default 8)");
static struct file *initial_file=NULL;
static int cloop_major=MAJOR_NR;
/* Number of buffered decompressed blocks */
#define BUFFERED_BLOCKS 8
struct cloop_device
{
/* Copied straight from the file */
struct cloop_head head;
/* An array of offsets of compressed blocks within the file */
loff_t *offsets;
/* We buffer some uncompressed blocks for performance */
int buffered_blocknum[BUFFERED_BLOCKS];
int current_bufnum;
void *buffer[BUFFERED_BLOCKS];
void *compressed_buffer;
size_t preload_array_size; /* Size of pointer array in blocks */
size_t preload_size; /* Number of successfully allocated blocks */
char **preload_cache; /* Pointers to preloaded blocks */
z_stream zstream;
struct file *backing_file; /* associated file */
struct inode *backing_inode; /* for bmap */
unsigned long largest_block;
unsigned int underlying_blksize;
int clo_number;
int refcnt;
struct block_device *bdev;
int isblkdev;
/* Lock for kernel block device queue */
spinlock_t queue_lock;
/* mutex for ioctl() */
struct mutex clo_ctl_mutex;
struct list_head clo_list;
struct task_struct *clo_thread;
wait_queue_head_t clo_event;
struct request_queue *clo_queue;
struct gendisk *clo_disk;
int suspended;
char clo_file_name[LO_NAME_SIZE];
};
/* Changed in 2.639: cloop_dev is now a an array of cloop_dev pointers,
so we can specify how many devices we need via parameters. */
static struct cloop_device **cloop_dev;
static const char *cloop_name=CLOOP_NAME;
static int cloop_count = 0;
#if (!(defined(CONFIG_ZLIB_INFLATE) || defined(CONFIG_ZLIB_INFLATE_MODULE))) /* Must be compiled into kernel. */
#error "Invalid Kernel configuration. CONFIG_ZLIB_INFLATE support is needed for cloop."
#endif
/* Use __get_free_pages instead of vmalloc, allows up to 32 pages,
* 2MB in one piece */
static void *cloop_malloc(size_t size)
{
/* kmalloc will fail after the system is running for a while, */
/* when large orders can't return contiguous memory. */
/* Let's just use vmalloc for now. :-/ */
/* int order = get_order(size); */
/* if(order <= KMALLOC_MAX_ORDER) */
/* return (void *)kmalloc(size, GFP_KERNEL); */
/* else if(order < MAX_ORDER) */
/* return (void *)__get_free_pages(GFP_KERNEL, order); */
return (void *)vmalloc(size);
}
static void cloop_free(void *mem, size_t size)
{
/* int order = get_order(size); */
/* if(order <= KMALLOC_MAX_ORDER) */
/* kfree(mem); */
/* else if(order < MAX_ORDER) */
/* free_pages((unsigned long)mem, order); */
/* else */
vfree(mem);
}
static int uncompress(struct cloop_device *clo,
unsigned char *dest, unsigned long *destLen,
unsigned char *source, unsigned long sourceLen)
{
/* Most of this code can be found in fs/cramfs/uncompress.c */
int err;
clo->zstream.next_in = source;
clo->zstream.avail_in = sourceLen;
clo->zstream.next_out = dest;
clo->zstream.avail_out = *destLen;
err = zlib_inflateReset(&clo->zstream);
if (err != Z_OK)
{
printk(KERN_ERR "%s: zlib_inflateReset error %d\n", cloop_name, err);
zlib_inflateEnd(&clo->zstream); zlib_inflateInit(&clo->zstream);
}
err = zlib_inflate(&clo->zstream, Z_FINISH);
*destLen = clo->zstream.total_out;
if (err != Z_STREAM_END) return err;
return Z_OK;
}
static ssize_t cloop_read_from_file(struct cloop_device *clo, struct file *f, char *buf,
loff_t pos, size_t buf_len)
{
size_t buf_done=0;
while (buf_done < buf_len)
{
size_t size = buf_len - buf_done, size_read;
/* kernel_read() only supports 32 bit offsets, so we use vfs_read() instead. */
/* int size_read = kernel_read(f, pos, buf + buf_done, size); */
mm_segment_t old_fs = get_fs();
set_fs(get_ds());
size_read = vfs_read(f, (void __user *)(buf + buf_done), size, &pos);
set_fs(old_fs);
if(size_read <= 0)
{
printk(KERN_ERR "%s: Read error %d at pos %Lu in file %s, "
"%d bytes lost.\n", cloop_name, (int)size_read, pos,
file, (int)size);
memset(buf + buf_len - size, 0, size);
break;
}
buf_done += size_read;
}
return buf_done;
}
/* This looks more complicated than it is */
/* Returns number of block buffer to use for this request */
static int cloop_load_buffer(struct cloop_device *clo, int blocknum)
{
unsigned int buf_done = 0;
unsigned long buflen;
unsigned int buf_length;
int ret;
int i;
if(blocknum > ntohl(clo->head.num_blocks) || blocknum < 0)
{
printk(KERN_WARNING "%s: Invalid block number %d requested.\n",
cloop_name, blocknum);
return -1;
}
/* Quick return if the block we seek is already in one of the buffers. */
/* Return number of buffer */
for(i=0; i<BUFFERED_BLOCKS; i++)
if (blocknum == clo->buffered_blocknum[i])
{
DEBUGP(KERN_INFO "cloop_load_buffer: Found buffered block %d\n", i);
return i;
}
buf_length = be64_to_cpu(clo->offsets[blocknum+1]) - be64_to_cpu(clo->offsets[blocknum]);
/* Load one compressed block from the file. */
cloop_read_from_file(clo, clo->backing_file, (char *)clo->compressed_buffer,
be64_to_cpu(clo->offsets[blocknum]), buf_length);
buflen = ntohl(clo->head.block_size);
/* Go to next position in the block ring buffer */
clo->current_bufnum++;
if(clo->current_bufnum >= BUFFERED_BLOCKS) clo->current_bufnum = 0;
/* Do the uncompression */
ret = uncompress(clo, clo->buffer[clo->current_bufnum], &buflen, clo->compressed_buffer,
buf_length);
/* DEBUGP("cloop: buflen after uncompress: %ld\n",buflen); */
if (ret != 0)
{
printk(KERN_ERR "%s: zlib decompression error %i uncompressing block %u %u/%lu/%u/%u "
"%Lu-%Lu\n", cloop_name, ret, blocknum,
ntohl(clo->head.block_size), buflen, buf_length, buf_done,
be64_to_cpu(clo->offsets[blocknum]), be64_to_cpu(clo->offsets[blocknum+1]));
clo->buffered_blocknum[clo->current_bufnum] = -1;
return -1;
}
clo->buffered_blocknum[clo->current_bufnum] = blocknum;
return clo->current_bufnum;
}
/* This function does all the real work. */
/* returns "uptodate" */
static int cloop_handle_request(struct cloop_device *clo, struct request *req)
{
int buffered_blocknum = -1;
int preloaded = 0;
loff_t offset = (loff_t) blk_rq_pos(req)<<9; /* req->sector<<9 */
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
struct bio_vec *bvec;
#else
struct bio_vec bvec;
#endif
struct req_iterator iter;
rq_for_each_segment(bvec, req, iter)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
unsigned long len = bvec->bv_len;
char *to_ptr = kmap(bvec->bv_page) + bvec->bv_offset;
#else
unsigned long len = bvec.bv_len;
char *to_ptr = kmap(bvec.bv_page) + bvec.bv_offset;
#endif
while(len > 0)
{
u_int32_t length_in_buffer;
loff_t block_offset = offset;
u_int32_t offset_in_buffer;
char *from_ptr;
/* do_div (div64.h) returns the 64bit division remainder and */
/* puts the result in the first argument, i.e. block_offset */
/* becomes the blocknumber to load, and offset_in_buffer the */
/* position in the buffer */
offset_in_buffer = do_div(block_offset, ntohl(clo->head.block_size));
/* Lookup preload cache */
if(block_offset < clo->preload_size && clo->preload_cache != NULL &&
clo->preload_cache[block_offset] != NULL)
{ /* Copy from cache */
preloaded = 1;
from_ptr = clo->preload_cache[block_offset];
}
else
{
preloaded = 0;
buffered_blocknum = cloop_load_buffer(clo,block_offset);
if(buffered_blocknum == -1) break; /* invalid data, leave inner loop */
/* Copy from buffer */
from_ptr = clo->buffer[buffered_blocknum];
}
/* Now, at least part of what we want will be in the buffer. */
length_in_buffer = ntohl(clo->head.block_size) - offset_in_buffer;
if(length_in_buffer > len)
{
/* DEBUGP("Warning: length_in_buffer=%u > len=%u\n",
length_in_buffer,len); */
length_in_buffer = len;
}
memcpy(to_ptr, from_ptr + offset_in_buffer, length_in_buffer);
to_ptr += length_in_buffer;
len -= length_in_buffer;
offset += length_in_buffer;
} /* while inner loop */
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
kunmap(bvec->bv_page);
#else
kunmap(bvec.bv_page);
#endif
} /* end rq_for_each_segment*/
return ((buffered_blocknum!=-1) || preloaded);
}
/* Adopted from loop.c, a kernel thread to handle physical reads and
* decompression. */
static int cloop_thread(void *data)
{
struct cloop_device *clo = data;
current->flags |= PF_NOFREEZE;
set_user_nice(current, -15);
while (!kthread_should_stop()||!list_empty(&clo->clo_list))
{
int err;
err = wait_event_interruptible(clo->clo_event, !list_empty(&clo->clo_list) ||
kthread_should_stop());
if(unlikely(err))
{
DEBUGP(KERN_ERR "cloop thread activated on error!? Continuing.\n");
continue;
}
if(!list_empty(&clo->clo_list))
{
struct request *req;
unsigned long flags;
int uptodate;
spin_lock_irq(&clo->queue_lock);
req = list_entry(clo->clo_list.next, struct request, queuelist);
list_del_init(&req->queuelist);
spin_unlock_irq(&clo->queue_lock);
uptodate = cloop_handle_request(clo, req);
spin_lock_irqsave(&clo->queue_lock, flags);
__blk_end_request_all(req, uptodate ? 0 : -EIO);
spin_unlock_irqrestore(&clo->queue_lock, flags);
}
}
DEBUGP(KERN_ERR "cloop_thread exited.\n");
return 0;
}
/* This is called by the kernel block queue management every now and then,
* with successive read requests qeued and sorted in a (hopefully)
* "most efficient way". spin_lock_irq() is being held by the kernel. */
static void cloop_do_request(struct request_queue *q)
{
struct request *req;
while((req = blk_fetch_request(q)) != NULL)
{
struct cloop_device *clo;
int rw;
/* quick sanity checks */
/* blk_fs_request() was removed in 2.6.36 */
if (unlikely(req == NULL || (req->cmd_type != REQ_TYPE_FS)))
goto error_continue;
rw = rq_data_dir(req);
if (unlikely(rw != READ && rw != READA))
{
DEBUGP("cloop_do_request: bad command\n");
goto error_continue;
}
clo = req->rq_disk->private_data;
if (unlikely(!clo->backing_file && !clo->suspended))
{
DEBUGP("cloop_do_request: not connected to a file\n");
goto error_continue;
}
list_add_tail(&req->queuelist, &clo->clo_list); /* Add to working list for thread */
wake_up(&clo->clo_event); /* Wake up cloop_thread */
continue; /* next request */
error_continue:
DEBUGP(KERN_ERR "cloop_do_request: Discarding request %p.\n", req);
req->errors++;
__blk_end_request_all(req, -EIO);
}
}
/* Read header and offsets from already opened file */
static int cloop_set_file(int cloop_num, struct file *file, char *filename)
{
struct cloop_device *clo = cloop_dev[cloop_num];
struct inode *inode;
char *bbuf=NULL;
unsigned int i, offsets_read, total_offsets;
int isblkdev;
int error = 0;
inode = file->f_path.dentry->d_inode;
isblkdev=S_ISBLK(inode->i_mode)?1:0;
if(!isblkdev&&!S_ISREG(inode->i_mode))
{
printk(KERN_ERR "%s: %s not a regular file or block device\n",
cloop_name, filename);
error=-EBADF; goto error_release;
}
clo->backing_file = file;
clo->backing_inode= inode ;
if(!isblkdev&&inode->i_size<sizeof(struct cloop_head))
{
printk(KERN_ERR "%s: %lu bytes (must be >= %u bytes)\n",
cloop_name, (unsigned long)inode->i_size,
(unsigned)sizeof(struct cloop_head));
error=-EBADF; goto error_release;
}
/* In suspended mode, we have done all checks necessary - FF */
if (clo->suspended)
return error;
if(isblkdev)
{
struct request_queue *q = bdev_get_queue(inode->i_bdev);
blk_queue_max_hw_sectors(clo->clo_queue, queue_max_hw_sectors(q)); /* Renamed in 2.6.34 */
blk_queue_max_segments(clo->clo_queue, queue_max_segments(q)); /* Renamed in 2.6.34 */
/* blk_queue_max_hw_segments(clo->clo_queue, queue_max_hw_segments(q)); */ /* Removed in 2.6.34 */
blk_queue_max_segment_size(clo->clo_queue, queue_max_segment_size(q));
blk_queue_segment_boundary(clo->clo_queue, queue_segment_boundary(q));
blk_queue_merge_bvec(clo->clo_queue, q->merge_bvec_fn);
clo->underlying_blksize = block_size(inode->i_bdev);
}
else
clo->underlying_blksize = PAGE_SIZE;
DEBUGP("Underlying blocksize is %u\n", clo->underlying_blksize);
bbuf = cloop_malloc(clo->underlying_blksize);
if(!bbuf)
{
printk(KERN_ERR "%s: out of kernel mem for block buffer (%lu bytes)\n",
cloop_name, (unsigned long)clo->underlying_blksize);
error=-ENOMEM; goto error_release;
}
total_offsets = 1; /* Dummy total_offsets: will be filled in first time around */
for (i = 0, offsets_read = 0; offsets_read < total_offsets; i++)
{
unsigned int offset = 0, num_readable;
size_t bytes_read = cloop_read_from_file(clo, file, bbuf,
i*clo->underlying_blksize,
clo->underlying_blksize);
if(bytes_read != clo->underlying_blksize)
{
printk(KERN_ERR "%s: Bad file, read() of first %lu bytes returned %d.\n",
cloop_name, (unsigned long)clo->underlying_blksize, (int)bytes_read);
error=-EBADF;
goto error_release;
}
/* Header will be in block zero */
if(i==0)
{
memcpy(&clo->head, bbuf, sizeof(struct cloop_head));
offset = sizeof(struct cloop_head);
if (ntohl(clo->head.block_size) % 512 != 0)
{
printk(KERN_ERR "%s: blocksize %u not multiple of 512\n",
cloop_name, ntohl(clo->head.block_size));
error=-EBADF; goto error_release;
}
if (clo->head.preamble[0x0B]!='V'||clo->head.preamble[0x0C]<'1')
{
printk(KERN_ERR "%s: Cannot read old 32-bit (version 0.68) images, "
"please use an older version of %s for this file.\n",
cloop_name, cloop_name);
error=-EBADF; goto error_release;
}
if (clo->head.preamble[0x0C]<'2')
{
printk(KERN_ERR "%s: Cannot read old architecture-dependent "
"(format <= 1.0) images, please use an older "
"version of %s for this file.\n",
cloop_name, cloop_name);
error=-EBADF; goto error_release;
}
total_offsets=ntohl(clo->head.num_blocks)+1;
if (!isblkdev && (sizeof(struct cloop_head)+sizeof(loff_t)*
total_offsets > inode->i_size))
{
printk(KERN_ERR "%s: file too small for %u blocks\n",
cloop_name, ntohl(clo->head.num_blocks));
error=-EBADF; goto error_release;
}
clo->offsets = cloop_malloc(sizeof(loff_t) * total_offsets);
if (!clo->offsets)
{
printk(KERN_ERR "%s: out of kernel mem for offsets\n", cloop_name);
error=-ENOMEM; goto error_release;
}
}
num_readable = MIN(total_offsets - offsets_read,
(clo->underlying_blksize - offset)
/ sizeof(loff_t));
memcpy(&clo->offsets[offsets_read], bbuf+offset, num_readable * sizeof(loff_t));
offsets_read += num_readable;
}
{ /* Search for largest block rather than estimate. KK. */
int i;
for(i=0;i<total_offsets-1;i++)
{
loff_t d=be64_to_cpu(clo->offsets[i+1]) - be64_to_cpu(clo->offsets[i]);
clo->largest_block=MAX(clo->largest_block,d);
}
printk(KERN_INFO "%s: %s: %u blocks, %u bytes/block, largest block is %lu bytes.\n",
cloop_name, filename, ntohl(clo->head.num_blocks),
ntohl(clo->head.block_size), clo->largest_block);
}
/* Combo kmalloc used too large chunks (>130000). */
{
int i;
for(i=0;i<BUFFERED_BLOCKS;i++)
{
clo->buffer[i] = cloop_malloc(ntohl(clo->head.block_size));
if(!clo->buffer[i])
{
printk(KERN_ERR "%s: out of memory for buffer %lu\n",
cloop_name, (unsigned long) ntohl(clo->head.block_size));
error=-ENOMEM; goto error_release_free;
}
}
}
clo->compressed_buffer = cloop_malloc(clo->largest_block);
if(!clo->compressed_buffer)
{
printk(KERN_ERR "%s: out of memory for compressed buffer %lu\n",
cloop_name, clo->largest_block);
error=-ENOMEM; goto error_release_free_buffer;
}
clo->zstream.workspace = cloop_malloc(zlib_inflate_workspacesize());
if(!clo->zstream.workspace)
{
printk(KERN_ERR "%s: out of mem for zlib working area %u\n",
cloop_name, zlib_inflate_workspacesize());
error=-ENOMEM; goto error_release_free_all;
}
zlib_inflateInit(&clo->zstream);
if(!isblkdev &&
be64_to_cpu(clo->offsets[ntohl(clo->head.num_blocks)]) != inode->i_size)
{
printk(KERN_ERR "%s: final offset wrong (%Lu not %Lu)\n",
cloop_name,
be64_to_cpu(clo->offsets[ntohl(clo->head.num_blocks)]),
inode->i_size);
cloop_free(clo->zstream.workspace, zlib_inflate_workspacesize()); clo->zstream.workspace=NULL;
goto error_release_free_all;
}
{
int i;
for(i=0; i<BUFFERED_BLOCKS; i++) clo->buffered_blocknum[i] = -1;
clo->current_bufnum=0;
}
set_capacity(clo->clo_disk, (sector_t)(ntohl(clo->head.num_blocks)*
(ntohl(clo->head.block_size)>>9)));
clo->clo_thread = kthread_create(cloop_thread, clo, "cloop%d", cloop_num);
if(IS_ERR(clo->clo_thread))
{
error = PTR_ERR(clo->clo_thread);
clo->clo_thread=NULL;
goto error_release_free_all;
}
if(preload > 0)
{
clo->preload_array_size = ((preload<=ntohl(clo->head.num_blocks))?preload:ntohl(clo->head.num_blocks));
clo->preload_size = 0;
if((clo->preload_cache = cloop_malloc(clo->preload_array_size * sizeof(char *))) != NULL)
{
int i;
for(i=0; i<clo->preload_array_size; i++)
{
if((clo->preload_cache[i] = cloop_malloc(ntohl(clo->head.block_size))) == NULL)
{ /* Out of memory */
printk(KERN_WARNING "%s: cloop_malloc(%d) failed for preload_cache[%d] (ignored).\n",
cloop_name, ntohl(clo->head.block_size), i);
break;
}
}
clo->preload_size = i;
for(i=0; i<clo->preload_size; i++)
{
int buffered_blocknum = cloop_load_buffer(clo,i);
if(buffered_blocknum >= 0)
{
memcpy(clo->preload_cache[i], clo->buffer[buffered_blocknum],
ntohl(clo->head.block_size));
}
else
{
printk(KERN_WARNING "%s: can't read block %d into preload cache, set to zero.\n",
cloop_name, i);
memset(clo->preload_cache[i], 0, ntohl(clo->head.block_size));
}
}
printk(KERN_INFO "%s: preloaded %d blocks into cache.\n", cloop_name,
(int)clo->preload_size);
}
else
{
/* It is not a fatal error if cloop_malloc(clo->preload_size)
* fails, then we just go without cache, but we should at least
* let the user know. */
printk(KERN_WARNING "%s: cloop_malloc(%d) failed, continuing without preloaded buffers.\n",
cloop_name, (int)(clo->preload_size * sizeof(char *)));
clo->preload_array_size = clo->preload_size = 0;
}
}
wake_up_process(clo->clo_thread);
/* Uncheck */
return error;
error_release_free_all:
cloop_free(clo->compressed_buffer, clo->largest_block);
clo->compressed_buffer=NULL;
error_release_free_buffer:
{
int i;
for(i=0; i<BUFFERED_BLOCKS; i++)
{
if(clo->buffer[i])
{
cloop_free(clo->buffer[i], ntohl(clo->head.block_size));
clo->buffer[i]=NULL;
}
}
}
error_release_free:
cloop_free(clo->offsets, sizeof(loff_t) * total_offsets);
clo->offsets=NULL;
error_release:
if(bbuf) cloop_free(bbuf, clo->underlying_blksize);
clo->backing_file=NULL;
return error;
}
/* Get file from ioctl arg (only losetup) */
static int cloop_set_fd(int cloop_num, struct file *clo_file,
struct block_device *bdev, unsigned int arg)
{
struct cloop_device *clo = cloop_dev[cloop_num];
struct file *file=NULL;
int error = 0;
/* Already an allocated file present */
if(clo->backing_file) return -EBUSY;
file = fget(arg); /* get filp struct from ioctl arg fd */
if(!file) return -EBADF;
error=cloop_set_file(cloop_num,file,"losetup_file");
set_device_ro(bdev, 1);
if(error) fput(file);
return error;
}
/* Drop file and free buffers, both ioctl and initial_file */
static int cloop_clr_fd(int cloop_num, struct block_device *bdev)
{
struct cloop_device *clo = cloop_dev[cloop_num];
struct file *filp = clo->backing_file;
int i;
if(clo->refcnt > 1) /* we needed one fd for the ioctl */
return -EBUSY;
if(filp==NULL) return -EINVAL;
if(clo->clo_thread) { kthread_stop(clo->clo_thread); clo->clo_thread=NULL; }
if(filp!=initial_file) fput(filp);
else { filp_close(initial_file,0); initial_file=NULL; }
clo->backing_file = NULL;
clo->backing_inode = NULL;
if(clo->offsets) { cloop_free(clo->offsets, clo->underlying_blksize); clo->offsets = NULL; }
if(clo->preload_cache)
{
for(i=0; i < clo->preload_size; i++)
cloop_free(clo->preload_cache[i], ntohl(clo->head.block_size));
cloop_free(clo->preload_cache, clo->preload_array_size * sizeof(char *));
clo->preload_cache = NULL;
clo->preload_size = clo->preload_array_size = 0;
}
for(i=0; i<BUFFERED_BLOCKS; i++)
if(clo->buffer[i]) { cloop_free(clo->buffer[i], ntohl(clo->head.block_size)); clo->buffer[i]=NULL; }
if(clo->compressed_buffer) { cloop_free(clo->compressed_buffer, clo->largest_block); clo->compressed_buffer = NULL; }
zlib_inflateEnd(&clo->zstream);
if(clo->zstream.workspace) { cloop_free(clo->zstream.workspace, zlib_inflate_workspacesize()); clo->zstream.workspace = NULL; }
if(bdev) invalidate_bdev(bdev);
if(clo->clo_disk) set_capacity(clo->clo_disk, 0);
return 0;
}
static int clo_suspend_fd(int cloop_num)
{
struct cloop_device *clo = cloop_dev[cloop_num];
struct file *filp = clo->backing_file;
if(filp==NULL || clo->suspended) return -EINVAL;
/* Suspend all running requests - FF */
clo->suspended=1;
if(filp!=initial_file) fput(filp);
else { filp_close(initial_file,0); initial_file=NULL; }
clo->backing_file = NULL;
clo->backing_inode = NULL;
return 0;
}
/* Copied from loop.c, stripped down to the really necessary */
static int cloop_set_status(struct cloop_device *clo,
const struct loop_info64 *info)
{
if (!clo->backing_file) return -ENXIO;
memcpy(clo->clo_file_name, info->lo_file_name, LO_NAME_SIZE);
clo->clo_file_name[LO_NAME_SIZE-1] = 0;
return 0;
}
static int cloop_get_status(struct cloop_device *clo,
struct loop_info64 *info)
{
struct file *file = clo->backing_file;
struct kstat stat;
int err;
if (!file) return -ENXIO;
err = vfs_getattr(&file->f_path, &stat);
if (err) return err;
memset(info, 0, sizeof(*info));
info->lo_number = clo->clo_number;
info->lo_device = huge_encode_dev(stat.dev);
info->lo_inode = stat.ino;
info->lo_rdevice = huge_encode_dev(clo->isblkdev ? stat.rdev : stat.dev);
info->lo_offset = 0;
info->lo_sizelimit = 0;
info->lo_flags = 0;
memcpy(info->lo_file_name, clo->clo_file_name, LO_NAME_SIZE);
return 0;
}
static void cloop_info64_from_old(const struct loop_info *info,
struct loop_info64 *info64)
{
memset(info64, 0, sizeof(*info64));
info64->lo_number = info->lo_number;
info64->lo_device = info->lo_device;
info64->lo_inode = info->lo_inode;
info64->lo_rdevice = info->lo_rdevice;
info64->lo_offset = info->lo_offset;
info64->lo_sizelimit = 0;
info64->lo_flags = info->lo_flags;
info64->lo_init[0] = info->lo_init[0];
info64->lo_init[1] = info->lo_init[1];
memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE);
}
static int cloop_info64_to_old(const struct loop_info64 *info64,
struct loop_info *info)
{
memset(info, 0, sizeof(*info));
info->lo_number = info64->lo_number;
info->lo_device = info64->lo_device;
info->lo_inode = info64->lo_inode;
info->lo_rdevice = info64->lo_rdevice;
info->lo_offset = info64->lo_offset;
info->lo_flags = info64->lo_flags;
info->lo_init[0] = info64->lo_init[0];
info->lo_init[1] = info64->lo_init[1];
memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE);
return 0;
}
static int cloop_set_status_old(struct cloop_device *clo,
const struct loop_info __user *arg)
{
struct loop_info info;
struct loop_info64 info64;
if (copy_from_user(&info, arg, sizeof (struct loop_info))) return -EFAULT;
cloop_info64_from_old(&info, &info64);
return cloop_set_status(clo, &info64);
}
static int cloop_set_status64(struct cloop_device *clo,
const struct loop_info64 __user *arg)
{
struct loop_info64 info64;
if (copy_from_user(&info64, arg, sizeof (struct loop_info64)))
return -EFAULT;
return cloop_set_status(clo, &info64);
}
static int cloop_get_status_old(struct cloop_device *clo,
struct loop_info __user *arg)
{
struct loop_info info;
struct loop_info64 info64;
int err = 0;
if (!arg) err = -EINVAL;
if (!err) err = cloop_get_status(clo, &info64);
if (!err) err = cloop_info64_to_old(&info64, &info);
if (!err && copy_to_user(arg, &info, sizeof(info))) err = -EFAULT;
return err;
}
static int cloop_get_status64(struct cloop_device *clo,
struct loop_info64 __user *arg)
{
struct loop_info64 info64;
int err = 0;
if (!arg) err = -EINVAL;
if (!err) err = cloop_get_status(clo, &info64);
if (!err && copy_to_user(arg, &info64, sizeof(info64))) err = -EFAULT;
return err;
}
/* EOF get/set_status */
static int cloop_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
struct cloop_device *clo;
int cloop_num, err=0;
if (!bdev) return -EINVAL;
cloop_num = MINOR(bdev->bd_dev);
if (cloop_num < 0 || cloop_num > cloop_count-1) return -ENODEV;
clo = cloop_dev[cloop_num];
mutex_lock(&clo->clo_ctl_mutex);
switch (cmd)
{ /* We use the same ioctls that loop does */
case LOOP_CHANGE_FD:
case LOOP_SET_FD:
err = cloop_set_fd(cloop_num, NULL, bdev, arg);
if (err == 0 && clo->suspended)
{
/* Okay, we have again a backing file - get reqs again - FF */
clo->suspended=0;
}
break;
case LOOP_CLR_FD:
err = cloop_clr_fd(cloop_num, bdev);
break;
case LOOP_SET_STATUS:
err = cloop_set_status_old(clo, (struct loop_info __user *) arg);
break;
case LOOP_GET_STATUS:
err = cloop_get_status_old(clo, (struct loop_info __user *) arg);
break;
case LOOP_SET_STATUS64:
err = cloop_set_status64(clo, (struct loop_info64 __user *) arg);
break;
case LOOP_GET_STATUS64:
err = cloop_get_status64(clo, (struct loop_info64 __user *) arg);
break;
case CLOOP_SUSPEND:
err = clo_suspend_fd(cloop_num);
break;
default:
err = -EINVAL;
}
mutex_unlock(&clo->clo_ctl_mutex);
return err;
}
#ifdef CONFIG_COMPAT
static int cloop_compat_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
switch(cmd) {
case LOOP_SET_CAPACITY: /* Change arg */
case LOOP_CLR_FD: /* Change arg */
case LOOP_GET_STATUS64: /* Change arg */
case LOOP_SET_STATUS64: /* Change arg */
arg = (unsigned long) compat_ptr(arg);
case LOOP_SET_STATUS: /* unchanged */
case LOOP_GET_STATUS: /* unchanged */
case LOOP_SET_FD: /* unchanged */
case LOOP_CHANGE_FD: /* unchanged */
return cloop_ioctl(bdev, mode, cmd, arg);
break;
}
return -ENOIOCTLCMD;
}
#endif
static int cloop_open(struct block_device *bdev, fmode_t mode)
{
int cloop_num;
if(!bdev) return -EINVAL;
cloop_num=MINOR(bdev->bd_dev);
if(cloop_num > cloop_count-1) return -ENODEV;
/* Allow write open for ioctl, but not for mount. */
/* losetup uses write-open and flags=0x8002 to set a new file */
if(mode & FMODE_WRITE)
{
printk(KERN_WARNING "%s: Can't open device read-write in mode 0x%x\n", cloop_name, mode);
return -EROFS;
}
cloop_dev[cloop_num]->refcnt+=1;
return 0;
}
static void cloop_close(struct gendisk *disk, fmode_t mode)
{
int cloop_num;
if(!disk) return;
cloop_num=((struct cloop_device *)disk->private_data)->clo_number;
if(cloop_num < 0 || cloop_num > (cloop_count-1)) return;
cloop_dev[cloop_num]->refcnt-=1;
}
static struct block_device_operations clo_fops =
{
owner: THIS_MODULE,
open: cloop_open,
release: cloop_close,
#ifdef CONFIG_COMPAT
compat_ioctl: cloop_compat_ioctl,
#endif
ioctl: cloop_ioctl
/* locked_ioctl ceased to exist in 2.6.36 */
};
static int cloop_register_blkdev(int major_nr)
{
return register_blkdev(major_nr, cloop_name);
}
static int cloop_unregister_blkdev(void)
{
unregister_blkdev(cloop_major, cloop_name);
return 0;
}
static int cloop_alloc(int cloop_num)
{
struct cloop_device *clo = (struct cloop_device *) cloop_malloc(sizeof(struct cloop_device));;
if(clo == NULL) goto error_out;
cloop_dev[cloop_num] = clo;
memset(clo, 0, sizeof(struct cloop_device));
clo->clo_number = cloop_num;
clo->clo_thread = NULL;
init_waitqueue_head(&clo->clo_event);
spin_lock_init(&clo->queue_lock);
mutex_init(&clo->clo_ctl_mutex);
INIT_LIST_HEAD(&clo->clo_list);
clo->clo_queue = blk_init_queue(cloop_do_request, &clo->queue_lock);
if(!clo->clo_queue)
{
printk(KERN_ERR "%s: Unable to alloc queue[%d]\n", cloop_name, cloop_num);
goto error_out;
}
clo->clo_queue->queuedata = clo;
clo->clo_disk = alloc_disk(1);
if(!clo->clo_disk)
{
printk(KERN_ERR "%s: Unable to alloc disk[%d]\n", cloop_name, cloop_num);
goto error_disk;
}
clo->clo_disk->major = cloop_major;
clo->clo_disk->first_minor = cloop_num;
clo->clo_disk->fops = &clo_fops;
clo->clo_disk->queue = clo->clo_queue;
clo->clo_disk->private_data = clo;
sprintf(clo->clo_disk->disk_name, "%s%d", cloop_name, cloop_num);
add_disk(clo->clo_disk);
return 0;
error_disk:
blk_cleanup_queue(clo->clo_queue);
error_out:
return -ENOMEM;
}
static void cloop_dealloc(int cloop_num)
{
struct cloop_device *clo = cloop_dev[cloop_num];
if(clo == NULL) return;
del_gendisk(clo->clo_disk);
blk_cleanup_queue(clo->clo_queue);
put_disk(clo->clo_disk);
cloop_free(clo, sizeof(struct cloop_device));
cloop_dev[cloop_num] = NULL;
}
static int __init cloop_init(void)
{
int error=0;
printk("%s: Initializing %s v"CLOOP_VERSION"\n", cloop_name, cloop_name);
cloop_dev = (struct cloop_device **)cloop_malloc(cloop_max * sizeof(struct cloop_device *));
if(cloop_dev == NULL) return -ENOMEM;
memset(cloop_dev, 0, cloop_max * sizeof(struct cloop_device *));
cloop_count=0;
cloop_major=MAJOR_NR;
if(cloop_register_blkdev(MAJOR_NR))
{
printk(KERN_WARNING "%s: Unable to get major device %d\n", cloop_name,
MAJOR_NR);
/* Try dynamic allocation */
if((cloop_major=cloop_register_blkdev(0))<0)
{
printk(KERN_ERR "%s: Unable to get dynamic major device\n", cloop_name);
error = -EIO;
goto init_out_cloop_free;
}
printk(KERN_INFO "%s: Got dynamic major device %d, "
"mknod /dev/%s b %d 0\n",
cloop_name, cloop_major, cloop_name, cloop_major);
}
while(cloop_count<cloop_max)
if((error=cloop_alloc(cloop_count))!=0) break; else ++cloop_count;
if(!cloop_count) goto init_out_dealloc;
printk(KERN_INFO "%s: loaded (max %d devices)\n", cloop_name, cloop_count);
if(file) /* global file name for first cloop-Device is a module option string. */
{
int namelen = strlen(file);
if(namelen<1 ||
(initial_file=filp_open(file,O_RDONLY|O_LARGEFILE,0x00))==NULL ||
IS_ERR(initial_file))
{
error=PTR_ERR(initial_file);
if(!error) error=-EINVAL;
initial_file=NULL; /* if IS_ERR, it's NOT open. */
}
else
error=cloop_set_file(0,initial_file,file);
if(error)
{
printk(KERN_ERR
"%s: Unable to get file %s for cloop device, error %d\n",
cloop_name, file, error);
goto init_out_dealloc;
}
if(namelen >= LO_NAME_SIZE) namelen = LO_NAME_SIZE-1;
memcpy(cloop_dev[0]->clo_file_name, file, namelen);
cloop_dev[0]->clo_file_name[namelen] = 0;
}
return 0;
init_out_dealloc:
while (cloop_count>0) cloop_dealloc(--cloop_count);
cloop_unregister_blkdev();
init_out_cloop_free:
cloop_free(cloop_dev, cloop_max * sizeof(struct cloop_device *));
cloop_dev = NULL;
return error;
}
static void __exit cloop_exit(void)
{
int error=0;
if((error=cloop_unregister_blkdev())!=0)
{
printk(KERN_ERR "%s: cannot unregister block device\n", cloop_name);
return;
}
while(cloop_count>0)
{
--cloop_count;
if(cloop_dev[cloop_count]->backing_file) cloop_clr_fd(cloop_count, NULL);
cloop_dealloc(cloop_count);
}
printk("%s: unloaded.\n", cloop_name);
}
/* The cloop init and exit function registration (especially needed for Kernel 2.6) */
module_init(cloop_init);
module_exit(cloop_exit);
#include <linux/vermagic.h>
#include <linux/compiler.h>
MODULE_INFO(vermagic, VERMAGIC_STRING);
|