[PATCH v3] qnx4: qnx4_block_map error handling

From: Tong Zhang
Date: Mon Nov 02 2020 - 18:16:27 EST


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

Signed-off-by: Tong Zhang <ztong0001@xxxxxxxxx>
---
v2: also check other callers according to Anders Larsen's<al@xxxxxxxxxxx> comment
v3: change error code from EIO to ~0ull to avoid potential compiler
warning on signed/unsigned comparison
fs/qnx4/dir.c | 2 ++
fs/qnx4/inode.c | 6 ++++--
fs/qnx4/namei.c | 3 +++
3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/qnx4/dir.c b/fs/qnx4/dir.c
index a6ee23aadd28..0ff7b9f6a887 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 == ~0ull)
+ 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..b4fff2db6c7e 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 == ~0ull)
+ return -EIO;
if ( phys ) {
// logical block is before EOF
map_bh(bh, inode->i_sb, phys);
@@ -98,12 +100,12 @@ unsigned long qnx4_block_map( struct inode *inode, long iblock )
bh = sb_bread(inode->i_sb, i_xblk - 1);
if ( !bh ) {
QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1));
- return -EIO;
+ return ~0ull;
}
xblk = (struct qnx4_xblk*)bh->b_data;
if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) {
QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk));
- return -EIO;
+ return ~0ull;
}
}
block = try_extent(&xblk->xblk_xtnts[ix], &offset);
diff --git a/fs/qnx4/namei.c b/fs/qnx4/namei.c
index 8d72221735d7..c665ba730c11 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 == ~0ull)
+ 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