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Diffstat (limited to 'fs/squashfs/block.c')
-rw-r--r--fs/squashfs/block.c130
1 files changed, 37 insertions, 93 deletions
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 2a796031034..0cea9b9236d 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -2,7 +2,7 @@
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
- * Phillip Lougher <phillip@lougher.demon.co.uk>
+ * Phillip Lougher <phillip@squashfs.org.uk>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -29,15 +29,14 @@
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/slab.h>
-#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
-#include <linux/zlib.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
/*
* Read the metadata block length, this is stored in the first two
@@ -65,6 +64,14 @@ static struct buffer_head *get_block_length(struct super_block *sb,
*length = (unsigned char) bh->b_data[*offset] |
(unsigned char) bh->b_data[*offset + 1] << 8;
*offset += 2;
+
+ if (*offset == msblk->devblksize) {
+ put_bh(bh);
+ bh = sb_bread(sb, ++(*cur_index));
+ if (bh == NULL)
+ return NULL;
+ *offset = 0;
+ }
}
return bh;
@@ -77,20 +84,20 @@ static struct buffer_head *get_block_length(struct super_block *sb,
* filesystem), otherwise the length is obtained from the first two bytes of
* the metadata block. A bit in the length field indicates if the block
* is stored uncompressed in the filesystem (usually because compression
- * generated a larger block - this does occasionally happen with zlib).
+ * generated a larger block - this does occasionally happen with compression
+ * algorithms).
*/
-int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
- int length, u64 *next_index, int srclength, int pages)
+int squashfs_read_data(struct super_block *sb, u64 index, int length,
+ u64 *next_index, struct squashfs_page_actor *output)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
struct buffer_head **bh;
int offset = index & ((1 << msblk->devblksize_log2) - 1);
u64 cur_index = index >> msblk->devblksize_log2;
- int bytes, compressed, b = 0, k = 0, page = 0, avail;
+ int bytes, compressed, b = 0, k = 0, avail, i;
-
- bh = kcalloc((msblk->block_size >> msblk->devblksize_log2) + 1,
- sizeof(*bh), GFP_KERNEL);
+ bh = kcalloc(((output->length + msblk->devblksize - 1)
+ >> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL);
if (bh == NULL)
return -ENOMEM;
@@ -105,9 +112,9 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
*next_index = index + length;
TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n",
- index, compressed ? "" : "un", length, srclength);
+ index, compressed ? "" : "un", length, output->length);
- if (length < 0 || length > srclength ||
+ if (length < 0 || length > output->length ||
(index + length) > msblk->bytes_used)
goto read_failure;
@@ -139,7 +146,7 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
TRACE("Block @ 0x%llx, %scompressed size %d\n", index,
compressed ? "" : "un", length);
- if (length < 0 || length > srclength ||
+ if (length < 0 || length > output->length ||
(index + length) > msblk->bytes_used)
goto block_release;
@@ -152,97 +159,36 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
ll_rw_block(READ, b - 1, bh + 1);
}
- if (compressed) {
- int zlib_err = 0, zlib_init = 0;
-
- /*
- * Uncompress block.
- */
-
- mutex_lock(&msblk->read_data_mutex);
-
- msblk->stream.avail_out = 0;
- msblk->stream.avail_in = 0;
-
- bytes = length;
- do {
- if (msblk->stream.avail_in == 0 && k < b) {
- avail = min(bytes, msblk->devblksize - offset);
- bytes -= avail;
- wait_on_buffer(bh[k]);
- if (!buffer_uptodate(bh[k]))
- goto release_mutex;
-
- if (avail == 0) {
- offset = 0;
- put_bh(bh[k++]);
- continue;
- }
-
- msblk->stream.next_in = bh[k]->b_data + offset;
- msblk->stream.avail_in = avail;
- offset = 0;
- }
-
- if (msblk->stream.avail_out == 0 && page < pages) {
- msblk->stream.next_out = buffer[page++];
- msblk->stream.avail_out = PAGE_CACHE_SIZE;
- }
-
- if (!zlib_init) {
- zlib_err = zlib_inflateInit(&msblk->stream);
- if (zlib_err != Z_OK) {
- ERROR("zlib_inflateInit returned"
- " unexpected result 0x%x,"
- " srclength %d\n", zlib_err,
- srclength);
- goto release_mutex;
- }
- zlib_init = 1;
- }
-
- zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
-
- if (msblk->stream.avail_in == 0 && k < b)
- put_bh(bh[k++]);
- } while (zlib_err == Z_OK);
-
- if (zlib_err != Z_STREAM_END) {
- ERROR("zlib_inflate error, data probably corrupt\n");
- goto release_mutex;
- }
+ for (i = 0; i < b; i++) {
+ wait_on_buffer(bh[i]);
+ if (!buffer_uptodate(bh[i]))
+ goto block_release;
+ }
- zlib_err = zlib_inflateEnd(&msblk->stream);
- if (zlib_err != Z_OK) {
- ERROR("zlib_inflate error, data probably corrupt\n");
- goto release_mutex;
- }
- length = msblk->stream.total_out;
- mutex_unlock(&msblk->read_data_mutex);
+ if (compressed) {
+ length = squashfs_decompress(msblk, bh, b, offset, length,
+ output);
+ if (length < 0)
+ goto read_failure;
} else {
/*
* Block is uncompressed.
*/
- int i, in, pg_offset = 0;
-
- for (i = 0; i < b; i++) {
- wait_on_buffer(bh[i]);
- if (!buffer_uptodate(bh[i]))
- goto block_release;
- }
+ int in, pg_offset = 0;
+ void *data = squashfs_first_page(output);
for (bytes = length; k < b; k++) {
in = min(bytes, msblk->devblksize - offset);
bytes -= in;
while (in) {
if (pg_offset == PAGE_CACHE_SIZE) {
- page++;
+ data = squashfs_next_page(output);
pg_offset = 0;
}
avail = min_t(int, in, PAGE_CACHE_SIZE -
pg_offset);
- memcpy(buffer[page] + pg_offset,
- bh[k]->b_data + offset, avail);
+ memcpy(data + pg_offset, bh[k]->b_data + offset,
+ avail);
in -= avail;
pg_offset += avail;
offset += avail;
@@ -250,14 +196,12 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index,
offset = 0;
put_bh(bh[k]);
}
+ squashfs_finish_page(output);
}
kfree(bh);
return length;
-release_mutex:
- mutex_unlock(&msblk->read_data_mutex);
-
block_release:
for (; k < b; k++)
put_bh(bh[k]);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 15:03:12 +0000