linux-stable/fs/isofs/compress.c
Yinghai Lu d97b07c54f initramfs: support initramfs that is bigger than 2GiB
Now with 64bit bzImage and kexec tools, we support ramdisk that size is
bigger than 2g, as we could put it above 4G.

Found compressed initramfs image could not be decompressed properly.  It
turns out that image length is int during decompress detection, and it
will become < 0 when length is more than 2G.  Furthermore, during
decompressing len as int is used for inbuf count, that has problem too.

Change len to long, that should be ok as on 32 bit platform long is
32bits.

Tested with following compressed initramfs image as root with kexec.
	gzip, bzip2, xz, lzma, lzop, lz4.
run time for populate_rootfs():
   size        name       Nehalem-EX  Westmere-EX  Ivybridge-EX
 9034400256 root_img     :   26s           24s          30s
 3561095057 root_img.lz4 :   28s           27s          27s
 3459554629 root_img.lzo :   29s           29s          28s
 3219399480 root_img.gz  :   64s           62s          49s
 2251594592 root_img.xz  :  262s          260s         183s
 2226366598 root_img.lzma:  386s          376s         277s
 2901482513 root_img.bz2 :  635s          599s

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rashika Kheria <rashika.kheria@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: P J P <ppandit@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: "Daniel M. Weeks" <dan@danweeks.net>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:26 -07:00

380 lines
10 KiB
C

/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright 2001 H. Peter Anvin - All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
* USA; either version 2 of the License, or (at your option) any later
* version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* linux/fs/isofs/compress.c
*
* Transparent decompression of files on an iso9660 filesystem
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/zlib.h>
#include "isofs.h"
#include "zisofs.h"
/* This should probably be global. */
static char zisofs_sink_page[PAGE_CACHE_SIZE];
/*
* This contains the zlib memory allocation and the mutex for the
* allocation; this avoids failures at block-decompression time.
*/
static void *zisofs_zlib_workspace;
static DEFINE_MUTEX(zisofs_zlib_lock);
/*
* Read data of @inode from @block_start to @block_end and uncompress
* to one zisofs block. Store the data in the @pages array with @pcount
* entries. Start storing at offset @poffset of the first page.
*/
static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
loff_t block_end, int pcount,
struct page **pages, unsigned poffset,
int *errp)
{
unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
unsigned int bufsize = ISOFS_BUFFER_SIZE(inode);
unsigned int bufshift = ISOFS_BUFFER_BITS(inode);
unsigned int bufmask = bufsize - 1;
int i, block_size = block_end - block_start;
z_stream stream = { .total_out = 0,
.avail_in = 0,
.avail_out = 0, };
int zerr;
int needblocks = (block_size + (block_start & bufmask) + bufmask)
>> bufshift;
int haveblocks;
blkcnt_t blocknum;
struct buffer_head *bhs[needblocks + 1];
int curbh, curpage;
if (block_size > deflateBound(1UL << zisofs_block_shift)) {
*errp = -EIO;
return 0;
}
/* Empty block? */
if (block_size == 0) {
for ( i = 0 ; i < pcount ; i++ ) {
if (!pages[i])
continue;
memset(page_address(pages[i]), 0, PAGE_CACHE_SIZE);
flush_dcache_page(pages[i]);
SetPageUptodate(pages[i]);
}
return ((loff_t)pcount) << PAGE_CACHE_SHIFT;
}
/* Because zlib is not thread-safe, do all the I/O at the top. */
blocknum = block_start >> bufshift;
memset(bhs, 0, (needblocks + 1) * sizeof(struct buffer_head *));
haveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks);
ll_rw_block(READ, haveblocks, bhs);
curbh = 0;
curpage = 0;
/*
* First block is special since it may be fractional. We also wait for
* it before grabbing the zlib mutex; odds are that the subsequent
* blocks are going to come in in short order so we don't hold the zlib
* mutex longer than necessary.
*/
if (!bhs[0])
goto b_eio;
wait_on_buffer(bhs[0]);
if (!buffer_uptodate(bhs[0])) {
*errp = -EIO;
goto b_eio;
}
stream.workspace = zisofs_zlib_workspace;
mutex_lock(&zisofs_zlib_lock);
zerr = zlib_inflateInit(&stream);
if (zerr != Z_OK) {
if (zerr == Z_MEM_ERROR)
*errp = -ENOMEM;
else
*errp = -EIO;
printk(KERN_DEBUG "zisofs: zisofs_inflateInit returned %d\n",
zerr);
goto z_eio;
}
while (curpage < pcount && curbh < haveblocks &&
zerr != Z_STREAM_END) {
if (!stream.avail_out) {
if (pages[curpage]) {
stream.next_out = page_address(pages[curpage])
+ poffset;
stream.avail_out = PAGE_CACHE_SIZE - poffset;
poffset = 0;
} else {
stream.next_out = (void *)&zisofs_sink_page;
stream.avail_out = PAGE_CACHE_SIZE;
}
}
if (!stream.avail_in) {
wait_on_buffer(bhs[curbh]);
if (!buffer_uptodate(bhs[curbh])) {
*errp = -EIO;
break;
}
stream.next_in = bhs[curbh]->b_data +
(block_start & bufmask);
stream.avail_in = min_t(unsigned, bufsize -
(block_start & bufmask),
block_size);
block_size -= stream.avail_in;
block_start = 0;
}
while (stream.avail_out && stream.avail_in) {
zerr = zlib_inflate(&stream, Z_SYNC_FLUSH);
if (zerr == Z_BUF_ERROR && stream.avail_in == 0)
break;
if (zerr == Z_STREAM_END)
break;
if (zerr != Z_OK) {
/* EOF, error, or trying to read beyond end of input */
if (zerr == Z_MEM_ERROR)
*errp = -ENOMEM;
else {
printk(KERN_DEBUG
"zisofs: zisofs_inflate returned"
" %d, inode = %lu,"
" page idx = %d, bh idx = %d,"
" avail_in = %ld,"
" avail_out = %ld\n",
zerr, inode->i_ino, curpage,
curbh, stream.avail_in,
stream.avail_out);
*errp = -EIO;
}
goto inflate_out;
}
}
if (!stream.avail_out) {
/* This page completed */
if (pages[curpage]) {
flush_dcache_page(pages[curpage]);
SetPageUptodate(pages[curpage]);
}
curpage++;
}
if (!stream.avail_in)
curbh++;
}
inflate_out:
zlib_inflateEnd(&stream);
z_eio:
mutex_unlock(&zisofs_zlib_lock);
b_eio:
for (i = 0; i < haveblocks; i++)
brelse(bhs[i]);
return stream.total_out;
}
/*
* Uncompress data so that pages[full_page] is fully uptodate and possibly
* fills in other pages if we have data for them.
*/
static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
struct page **pages)
{
loff_t start_off, end_off;
loff_t block_start, block_end;
unsigned int header_size = ISOFS_I(inode)->i_format_parm[0];
unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
unsigned int blockptr;
loff_t poffset = 0;
blkcnt_t cstart_block, cend_block;
struct buffer_head *bh;
unsigned int blkbits = ISOFS_BUFFER_BITS(inode);
unsigned int blksize = 1 << blkbits;
int err;
loff_t ret;
BUG_ON(!pages[full_page]);
/*
* We want to read at least 'full_page' page. Because we have to
* uncompress the whole compression block anyway, fill the surrounding
* pages with the data we have anyway...
*/
start_off = page_offset(pages[full_page]);
end_off = min_t(loff_t, start_off + PAGE_CACHE_SIZE, inode->i_size);
cstart_block = start_off >> zisofs_block_shift;
cend_block = (end_off + (1 << zisofs_block_shift) - 1)
>> zisofs_block_shift;
WARN_ON(start_off - (full_page << PAGE_CACHE_SHIFT) !=
((cstart_block << zisofs_block_shift) & PAGE_CACHE_MASK));
/* Find the pointer to this specific chunk */
/* Note: we're not using isonum_731() here because the data is known aligned */
/* Note: header_size is in 32-bit words (4 bytes) */
blockptr = (header_size + cstart_block) << 2;
bh = isofs_bread(inode, blockptr >> blkbits);
if (!bh)
return -EIO;
block_start = le32_to_cpu(*(__le32 *)
(bh->b_data + (blockptr & (blksize - 1))));
while (cstart_block < cend_block && pcount > 0) {
/* Load end of the compressed block in the file */
blockptr += 4;
/* Traversed to next block? */
if (!(blockptr & (blksize - 1))) {
brelse(bh);
bh = isofs_bread(inode, blockptr >> blkbits);
if (!bh)
return -EIO;
}
block_end = le32_to_cpu(*(__le32 *)
(bh->b_data + (blockptr & (blksize - 1))));
if (block_start > block_end) {
brelse(bh);
return -EIO;
}
err = 0;
ret = zisofs_uncompress_block(inode, block_start, block_end,
pcount, pages, poffset, &err);
poffset += ret;
pages += poffset >> PAGE_CACHE_SHIFT;
pcount -= poffset >> PAGE_CACHE_SHIFT;
full_page -= poffset >> PAGE_CACHE_SHIFT;
poffset &= ~PAGE_CACHE_MASK;
if (err) {
brelse(bh);
/*
* Did we finish reading the page we really wanted
* to read?
*/
if (full_page < 0)
return 0;
return err;
}
block_start = block_end;
cstart_block++;
}
if (poffset && *pages) {
memset(page_address(*pages) + poffset, 0,
PAGE_CACHE_SIZE - poffset);
flush_dcache_page(*pages);
SetPageUptodate(*pages);
}
return 0;
}
/*
* When decompressing, we typically obtain more than one page
* per reference. We inject the additional pages into the page
* cache as a form of readahead.
*/
static int zisofs_readpage(struct file *file, struct page *page)
{
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
int err;
int i, pcount, full_page;
unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
unsigned int zisofs_pages_per_cblock =
PAGE_CACHE_SHIFT <= zisofs_block_shift ?
(1 << (zisofs_block_shift - PAGE_CACHE_SHIFT)) : 0;
struct page *pages[max_t(unsigned, zisofs_pages_per_cblock, 1)];
pgoff_t index = page->index, end_index;
end_index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
/*
* If this page is wholly outside i_size we just return zero;
* do_generic_file_read() will handle this for us
*/
if (index >= end_index) {
SetPageUptodate(page);
unlock_page(page);
return 0;
}
if (PAGE_CACHE_SHIFT <= zisofs_block_shift) {
/* We have already been given one page, this is the one
we must do. */
full_page = index & (zisofs_pages_per_cblock - 1);
pcount = min_t(int, zisofs_pages_per_cblock,
end_index - (index & ~(zisofs_pages_per_cblock - 1)));
index -= full_page;
} else {
full_page = 0;
pcount = 1;
}
pages[full_page] = page;
for (i = 0; i < pcount; i++, index++) {
if (i != full_page)
pages[i] = grab_cache_page_nowait(mapping, index);
if (pages[i]) {
ClearPageError(pages[i]);
kmap(pages[i]);
}
}
err = zisofs_fill_pages(inode, full_page, pcount, pages);
/* Release any residual pages, do not SetPageUptodate */
for (i = 0; i < pcount; i++) {
if (pages[i]) {
flush_dcache_page(pages[i]);
if (i == full_page && err)
SetPageError(pages[i]);
kunmap(pages[i]);
unlock_page(pages[i]);
if (i != full_page)
page_cache_release(pages[i]);
}
}
/* At this point, err contains 0 or -EIO depending on the "critical" page */
return err;
}
const struct address_space_operations zisofs_aops = {
.readpage = zisofs_readpage,
/* No sync_page operation supported? */
/* No bmap operation supported */
};
int __init zisofs_init(void)
{
zisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());
if ( !zisofs_zlib_workspace )
return -ENOMEM;
return 0;
}
void zisofs_cleanup(void)
{
vfree(zisofs_zlib_workspace);
}