Commit 98310e58 authored by David VomLehn's avatar David VomLehn Committed by Linus Torvalds
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cramfs: propagate uncompression errors 



Decompression errors can arise due to corruption of compressed blocks on
flash or in memory.  This patch propagates errors detected during
decompression back to the block layer.

Signed-off-by: default avatarDavid VomLehn <dvomlehn@cisco.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6e873ec7

fs/cramfs/inode.c

+26 −10
Original line number Diff line number Diff line
@@ -459,11 +459,14 @@ static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, s 
static int cramfs_readpage(struct file *file, struct page * page)

{

	struct inode *inode = page->mapping->host;

	u32 maxblock, bytes_filled;

	u32 maxblock;

	int bytes_filled;

	void *pgdata;



	maxblock = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;

	bytes_filled = 0;

	pgdata = kmap(page);



	if (page->index < maxblock) {

		struct super_block *sb = inode->i_sb;

		u32 blkptr_offset = OFFSET(inode) + page->index*4;
@@ -472,30 +475,43 @@ static int cramfs_readpage(struct file *file, struct page * page) 
		start_offset = OFFSET(inode) + maxblock*4;

		mutex_lock(&read_mutex);

		if (page->index)

			start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4, 4);

		compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) - start_offset);

			start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4,

				4);

		compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) -

			start_offset);

		mutex_unlock(&read_mutex);

		pgdata = kmap(page);



		if (compr_len == 0)

			; /* hole */

		else if (compr_len > (PAGE_CACHE_SIZE << 1))

			printk(KERN_ERR "cramfs: bad compressed blocksize %u\n", compr_len);

		else {

		else if (unlikely(compr_len > (PAGE_CACHE_SIZE << 1))) {

			pr_err("cramfs: bad compressed blocksize %u\n",

				compr_len);

			goto err;

		} else {

			mutex_lock(&read_mutex);

			bytes_filled = cramfs_uncompress_block(pgdata,

				 PAGE_CACHE_SIZE,

				 cramfs_read(sb, start_offset, compr_len),

				 compr_len);

			mutex_unlock(&read_mutex);

			if (unlikely(bytes_filled < 0))

				goto err;

		}

	} else

		pgdata = kmap(page);

	}



	memset(pgdata + bytes_filled, 0, PAGE_CACHE_SIZE - bytes_filled);

	kunmap(page);

	flush_dcache_page(page);

	kunmap(page);

	SetPageUptodate(page);

	unlock_page(page);

	return 0;



err:

	kunmap(page);

	ClearPageUptodate(page);

	SetPageError(page);

	unlock_page(page);

	return 0;

}



static const struct address_space_operations cramfs_aops = {

fs/cramfs/uncompress.c

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) 
err:

	printk("Error %d while decompressing!\n", err);

	printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);

	return 0;

	return -EIO;

}



int cramfs_uncompress_init(void)