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: David VomLehn <dvomlehn@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David VomLehn 2009-04-02 16:59:15 -07:00 committed by Linus Torvalds
parent 6e873ec71d
commit 98310e581e
2 changed files with 27 additions and 11 deletions

View file

@ -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 = {

View file

@ -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)