[PATCH v2] qnx4: do not interpret -EIO as a correct address

[Tong Zhang]

qnx4_block_map() may return -EIO on funny qnx4 fs image, in this case do
not interpret -EIO as a correct address

Signed-off-by: Tong Zhang <ztong0...@gmail.com>
---
v2: also check other callers according to Anders Larsen's<a...@alarsen.net> 
comment
 fs/qnx4/dir.c   | 2 ++
 fs/qnx4/inode.c | 2 ++
 fs/qnx4/namei.c | 3 +++
 3 files changed, 7 insertions(+)

diff --git a/fs/qnx4/dir.c b/fs/qnx4/dir.c
index a6ee23aadd28..11aaf59f0411 100644
--- a/fs/qnx4/dir.c
+++ b/fs/qnx4/dir.c
@@ -31,6 +31,8 @@ static int qnx4_readdir(struct file *file, struct dir_context 
*ctx)
 
        while (ctx->pos < inode->i_size) {
                blknum = qnx4_block_map(inode, ctx->pos >> 
QNX4_BLOCK_SIZE_BITS);
+               if (blknum == -EIO)
+                       return -EIO;
                bh = sb_bread(inode->i_sb, blknum);
                if (bh == NULL) {
                        printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", 
blknum);
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index e8da1cde87b9..d3a40c5b1a9a 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -59,6 +59,8 @@ static int qnx4_get_block( struct inode *inode, sector_t 
iblock, struct buffer_h
        QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] 
iblock=[%ld]\n",inode->i_ino,iblock));
 
        phys = qnx4_block_map( inode, iblock );
+       if (phys == -EIO)
+               return -EIO;
        if ( phys ) {
                // logical block is before EOF
                map_bh(bh, inode->i_sb, phys);
diff --git a/fs/qnx4/namei.c b/fs/qnx4/namei.c
index 8d72221735d7..164e0c07e3ff 100644
--- a/fs/qnx4/namei.c
+++ b/fs/qnx4/namei.c
@@ -66,6 +66,8 @@ static struct buffer_head *qnx4_find_entry(int len, struct 
inode *dir,
        while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
                if (!bh) {
                        block = qnx4_block_map(dir, blkofs);
+                       if (block == -EIO)
+                               goto out;
                        if (block)
                                bh = sb_bread(dir->i_sb, block);
                        if (!bh) {
@@ -88,6 +90,7 @@ static struct buffer_head *qnx4_find_entry(int len, struct 
inode *dir,
                blkofs++;
        }
        brelse(bh);
+out:
        *res_dir = NULL;
        return NULL;
 }
-- 
2.25.1