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cramfs: propagate uncompression errors

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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
Download Patch File Download Diff File Expand all files Collapse all files

36
fs/cramfs/inode.c
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) static int cramfs_readpage(struct file *file, struct page * page)
{ {
struct inode *inode = page->mapping->host; struct inode *inode = page->mapping->host;
u32 maxblock, bytes_filled; u32 maxblock;
int bytes_filled;
void *pgdata; void *pgdata;
maxblock = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; maxblock = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
bytes_filled = 0; bytes_filled = 0;
pgdata = kmap(page);
if (page->index < maxblock) { if (page->index < maxblock) {
struct super_block *sb = inode->i_sb; struct super_block *sb = inode->i_sb;
u32 blkptr_offset = OFFSET(inode) + page->index*4; 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; start_offset = OFFSET(inode) + maxblock*4;
mutex_lock(&read_mutex); mutex_lock(&read_mutex);
if (page->index) if (page->index)
start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4, 4); start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4,
compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) - start_offset); 4);
compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) -
start_offset);
mutex_unlock(&read_mutex); mutex_unlock(&read_mutex);
pgdata = kmap(page);
if (compr_len == 0) if (compr_len == 0)
; /* hole */ ; /* hole */
else if (compr_len > (PAGE_CACHE_SIZE << 1)) else if (unlikely(compr_len > (PAGE_CACHE_SIZE << 1))) {
printk(KERN_ERR "cramfs: bad compressed blocksize %u\n", compr_len); pr_err("cramfs: bad compressed blocksize %u\n",
else { compr_len);
goto err;
} else {
mutex_lock(&read_mutex); mutex_lock(&read_mutex);
bytes_filled = cramfs_uncompress_block(pgdata, bytes_filled = cramfs_uncompress_block(pgdata,
PAGE_CACHE_SIZE, PAGE_CACHE_SIZE,
cramfs_read(sb, start_offset, compr_len), cramfs_read(sb, start_offset, compr_len),
compr_len); compr_len);
mutex_unlock(&read_mutex); 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); memset(pgdata + bytes_filled, 0, PAGE_CACHE_SIZE - bytes_filled);
kunmap(page);
flush_dcache_page(page); flush_dcache_page(page);
kunmap(page);
SetPageUptodate(page); SetPageUptodate(page);
unlock_page(page); unlock_page(page);
return 0; return 0;
err:
kunmap(page);
ClearPageUptodate(page);
SetPageError(page);
unlock_page(page);
return 0;
} }
static const struct address_space_operations cramfs_aops = { static const struct address_space_operations cramfs_aops = {

2
fs/cramfs/uncompress.c
View File

@@ -50,7 +50,7 @@ int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
err: err:
printk("Error %d while decompressing!\n", err); printk("Error %d while decompressing!\n", err);
printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
return 0; return -EIO;
} }
int cramfs_uncompress_init(void) int cramfs_uncompress_init(void)