From 98310e581e098514867573031b2bfa4ba89c0d93 Mon Sep 17 00:00:00 2001 From: David VomLehn Date: Thu, 2 Apr 2009 16:59:15 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/cramfs/inode.c | 36 ++++++++++++++++++++++++++---------- fs/cramfs/uncompress.c | 2 +- 2 files changed, 27 insertions(+), 11 deletions(-) diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index a07338d2d14..46e52980b98 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -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 = { diff --git a/fs/cramfs/uncompress.c b/fs/cramfs/uncompress.c index fc3ccb74626..023329800d2 100644 --- a/fs/cramfs/uncompress.c +++ b/fs/cramfs/uncompress.c @@ -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)