1 files changed, 0 insertions, 440 deletions
diff --git a/ANDROID_3.4.5/fs/squashfs/cache.c b/ANDROID_3.4.5/fs/squashfs/cache.c
deleted file mode 100644
index af0b7380..00000000
--- a/ANDROID_3.4.5/fs/squashfs/cache.c
+++ /dev/null
@@ -1,440 +0,0 @@
-/*
- * Squashfs - a compressed read only filesystem for Linux
- *
- * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
- * 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
- * as published by the Free Software Foundation; either version 2,
- * or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- * cache.c
- */
-
-/*
- * Blocks in Squashfs are compressed.  To avoid repeatedly decompressing
- * recently accessed data Squashfs uses two small metadata and fragment caches.
- *
- * This file implements a generic cache implementation used for both caches,
- * plus functions layered ontop of the generic cache implementation to
- * access the metadata and fragment caches.
- *
- * To avoid out of memory and fragmentation issues with vmalloc the cache
- * uses sequences of kmalloced PAGE_CACHE_SIZE buffers.
- *
- * It should be noted that the cache is not used for file datablocks, these
- * are decompressed and cached in the page-cache in the normal way.  The
- * cache is only used to temporarily cache fragment and metadata blocks
- * which have been read as as a result of a metadata (i.e. inode or
- * directory) or fragment access.  Because metadata and fragments are packed
- * together into blocks (to gain greater compression) the read of a particular
- * piece of metadata or fragment will retrieve other metadata/fragments which
- * have been packed with it, these because of locality-of-reference may be read
- * in the near future. Temporarily caching them ensures they are available for
- * near future access without requiring an additional read and decompress.
- */
-
-#include <linux/fs.h>
-#include <linux/vfs.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/wait.h>
-#include <linux/pagemap.h>
-
-#include "squashfs_fs.h"
-#include "squashfs_fs_sb.h"
-#include "squashfs.h"
-
-/*
- * Look-up block in cache, and increment usage count.  If not in cache, read
- * and decompress it from disk.
- */
-struct squashfs_cache_entry *squashfs_cache_get(struct super_block *sb,
-	struct squashfs_cache *cache, u64 block, int length)
-{
-	int i, n;
-	struct squashfs_cache_entry *entry;
-
-	spin_lock(&cache->lock);
-
-	while (1) {
-		for (i = cache->curr_blk, n = 0; n < cache->entries; n++) {
-			if (cache->entry[i].block == block) {
-				cache->curr_blk = i;
-				break;
-			}
-			i = (i + 1) % cache->entries;
-		}
-
-		if (n == cache->entries) {
-			/*
-			 * Block not in cache, if all cache entries are used
-			 * go to sleep waiting for one to become available.
-			 */
-			if (cache->unused == 0) {
-				cache->num_waiters++;
-				spin_unlock(&cache->lock);
-				wait_event(cache->wait_queue, cache->unused);
-				spin_lock(&cache->lock);
-				cache->num_waiters--;
-				continue;
-			}
-
-			/*
-			 * At least one unused cache entry.  A simple
-			 * round-robin strategy is used to choose the entry to
-			 * be evicted from the cache.
-			 */
-			i = cache->next_blk;
-			for (n = 0; n < cache->entries; n++) {
-				if (cache->entry[i].refcount == 0)
-					break;
-				i = (i + 1) % cache->entries;
-			}
-
-			cache->next_blk = (i + 1) % cache->entries;
-			entry = &cache->entry[i];
-
-			/*
-			 * Initialise chosen cache entry, and fill it in from
-			 * disk.
-			 */
-			cache->unused--;
-			entry->block = block;
-			entry->refcount = 1;
-			entry->pending = 1;
-			entry->num_waiters = 0;
-			entry->error = 0;
-			spin_unlock(&cache->lock);
-
-			entry->length = squashfs_read_data(sb, entry->data,
-				block, length, &entry->next_index,
-				cache->block_size, cache->pages);
-
-			spin_lock(&cache->lock);
-
-			if (entry->length < 0)
-				entry->error = entry->length;
-
-			entry->pending = 0;
-
-			/*
-			 * While filling this entry one or more other processes
-			 * have looked it up in the cache, and have slept
-			 * waiting for it to become available.
-			 */
-			if (entry->num_waiters) {
-				spin_unlock(&cache->lock);
-				wake_up_all(&entry->wait_queue);
-			} else
-				spin_unlock(&cache->lock);
-
-			goto out;
-		}
-
-		/*
-		 * Block already in cache.  Increment refcount so it doesn't
-		 * get reused until we're finished with it, if it was
-		 * previously unused there's one less cache entry available
-		 * for reuse.
-		 */
-		entry = &cache->entry[i];
-		if (entry->refcount == 0)
-			cache->unused--;
-		entry->refcount++;
-
-		/*
-		 * If the entry is currently being filled in by another process
-		 * go to sleep waiting for it to become available.
-		 */
-		if (entry->pending) {
-			entry->num_waiters++;
-			spin_unlock(&cache->lock);
-			wait_event(entry->wait_queue, !entry->pending);
-		} else
-			spin_unlock(&cache->lock);
-
-		goto out;
-	}
-
-out:
-	TRACE("Got %s %d, start block %lld, refcount %d, error %d\n",
-		cache->name, i, entry->block, entry->refcount, entry->error);
-
-	if (entry->error)
-		ERROR("Unable to read %s cache entry [%llx]\n", cache->name,
-							block);
-	return entry;
-}
-
-
-/*
- * Release cache entry, once usage count is zero it can be reused.
- */
-void squashfs_cache_put(struct squashfs_cache_entry *entry)
-{
-	struct squashfs_cache *cache = entry->cache;
-
-	spin_lock(&cache->lock);
-	entry->refcount--;
-	if (entry->refcount == 0) {
-		cache->unused++;
-		/*
-		 * If there's any processes waiting for a block to become
-		 * available, wake one up.
-		 */
-		if (cache->num_waiters) {
-			spin_unlock(&cache->lock);
-			wake_up(&cache->wait_queue);
-			return;
-		}
-	}
-	spin_unlock(&cache->lock);
-}
-
-/*
- * Delete cache reclaiming all kmalloced buffers.
- */
-void squashfs_cache_delete(struct squashfs_cache *cache)
-{
-	int i, j;
-
-	if (cache == NULL)
-		return;
-
-	for (i = 0; i < cache->entries; i++) {
-		if (cache->entry[i].data) {
-			for (j = 0; j < cache->pages; j++)
-				kfree(cache->entry[i].data[j]);
-			kfree(cache->entry[i].data);
-		}
-	}
-
-	kfree(cache->entry);
-	kfree(cache);
-}
-
-
-/*
- * Initialise cache allocating the specified number of entries, each of
- * size block_size.  To avoid vmalloc fragmentation issues each entry
- * is allocated as a sequence of kmalloced PAGE_CACHE_SIZE buffers.
- */
-struct squashfs_cache *squashfs_cache_init(char *name, int entries,
-	int block_size)
-{
-	int i, j;
-	struct squashfs_cache *cache = kzalloc(sizeof(*cache), GFP_KERNEL);
-
-	if (cache == NULL) {
-		ERROR("Failed to allocate %s cache\n", name);
-		return NULL;
-	}
-
-	cache->entry = kcalloc(entries, sizeof(*(cache->entry)), GFP_KERNEL);
-	if (cache->entry == NULL) {
-		ERROR("Failed to allocate %s cache\n", name);
-		goto cleanup;
-	}
-
-	cache->curr_blk = 0;
-	cache->next_blk = 0;
-	cache->unused = entries;
-	cache->entries = entries;
-	cache->block_size = block_size;
-	cache->pages = block_size >> PAGE_CACHE_SHIFT;
-	cache->pages = cache->pages ? cache->pages : 1;
-	cache->name = name;
-	cache->num_waiters = 0;
-	spin_lock_init(&cache->lock);
-	init_waitqueue_head(&cache->wait_queue);
-
-	for (i = 0; i < entries; i++) {
-		struct squashfs_cache_entry *entry = &cache->entry[i];
-
-		init_waitqueue_head(&cache->entry[i].wait_queue);
-		entry->cache = cache;
-		entry->block = SQUASHFS_INVALID_BLK;
-		entry->data = kcalloc(cache->pages, sizeof(void *), GFP_KERNEL);
-		if (entry->data == NULL) {
-			ERROR("Failed to allocate %s cache entry\n", name);
-			goto cleanup;
-		}
-
-		for (j = 0; j < cache->pages; j++) {
-			entry->data[j] = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
-			if (entry->data[j] == NULL) {
-				ERROR("Failed to allocate %s buffer\n", name);
-				goto cleanup;
-			}
-		}
-	}
-
-	return cache;
-
-cleanup:
-	squashfs_cache_delete(cache);
-	return NULL;
-}
-
-
-/*
- * Copy up to length bytes from cache entry to buffer starting at offset bytes
- * into the cache entry.  If there's not length bytes then copy the number of
- * bytes available.  In all cases return the number of bytes copied.
- */
-int squashfs_copy_data(void *buffer, struct squashfs_cache_entry *entry,
-		int offset, int length)
-{
-	int remaining = length;
-
-	if (length == 0)
-		return 0;
-	else if (buffer == NULL)
-		return min(length, entry->length - offset);
-
-	while (offset < entry->length) {
-		void *buff = entry->data[offset / PAGE_CACHE_SIZE]
-				+ (offset % PAGE_CACHE_SIZE);
-		int bytes = min_t(int, entry->length - offset,
-				PAGE_CACHE_SIZE - (offset % PAGE_CACHE_SIZE));
-
-		if (bytes >= remaining) {
-			memcpy(buffer, buff, remaining);
-			remaining = 0;
-			break;
-		}
-
-		memcpy(buffer, buff, bytes);
-		buffer += bytes;
-		remaining -= bytes;
-		offset += bytes;
-	}
-
-	return length - remaining;
-}
-
-
-/*
- * Read length bytes from metadata position <block, offset> (block is the
- * start of the compressed block on disk, and offset is the offset into
- * the block once decompressed).  Data is packed into consecutive blocks,
- * and length bytes may require reading more than one block.
- */
-int squashfs_read_metadata(struct super_block *sb, void *buffer,
-		u64 *block, int *offset, int length)
-{
-	struct squashfs_sb_info *msblk = sb->s_fs_info;
-	int bytes, res = length;
-	struct squashfs_cache_entry *entry;
-
-	TRACE("Entered squashfs_read_metadata [%llx:%x]\n", *block, *offset);
-
-	while (length) {
-		entry = squashfs_cache_get(sb, msblk->block_cache, *block, 0);
-		if (entry->error) {
-			res = entry->error;
-			goto error;
-		} else if (*offset >= entry->length) {
-			res = -EIO;
-			goto error;
-		}
-
-		bytes = squashfs_copy_data(buffer, entry, *offset, length);
-		if (buffer)
-			buffer += bytes;
-		length -= bytes;
-		*offset += bytes;
-
-		if (*offset == entry->length) {
-			*block = entry->next_index;
-			*offset = 0;
-		}
-
-		squashfs_cache_put(entry);
-	}
-
-	return res;
-
-error:
-	squashfs_cache_put(entry);
-	return res;
-}
-
-
-/*
- * Look-up in the fragmment cache the fragment located at <start_block> in the
- * filesystem.  If necessary read and decompress it from disk.
- */
-struct squashfs_cache_entry *squashfs_get_fragment(struct super_block *sb,
-				u64 start_block, int length)
-{
-	struct squashfs_sb_info *msblk = sb->s_fs_info;
-
-	return squashfs_cache_get(sb, msblk->fragment_cache, start_block,
-		length);
-}
-
-
-/*
- * Read and decompress the datablock located at <start_block> in the
- * filesystem.  The cache is used here to avoid duplicating locking and
- * read/decompress code.
- */
-struct squashfs_cache_entry *squashfs_get_datablock(struct super_block *sb,
-				u64 start_block, int length)
-{
-	struct squashfs_sb_info *msblk = sb->s_fs_info;
-
-	return squashfs_cache_get(sb, msblk->read_page, start_block, length);
-}
-
-
-/*
- * Read a filesystem table (uncompressed sequence of bytes) from disk
- */
-void *squashfs_read_table(struct super_block *sb, u64 block, int length)
-{
-	int pages = (length + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	int i, res;
-	void *table, *buffer, **data;
-
-	table = buffer = kmalloc(length, GFP_KERNEL);
-	if (table == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	data = kcalloc(pages, sizeof(void *), GFP_KERNEL);
-	if (data == NULL) {
-		res = -ENOMEM;
-		goto failed;
-	}
-
-	for (i = 0; i < pages; i++, buffer += PAGE_CACHE_SIZE)
-		data[i] = buffer;
-
-	res = squashfs_read_data(sb, data, block, length |
-		SQUASHFS_COMPRESSED_BIT_BLOCK, NULL, length, pages);
-
-	kfree(data);
-
-	if (res < 0)
-		goto failed;
-
-	return table;
-
-failed:
-	kfree(table);
-	return ERR_PTR(res);
-}