commit 46f870d690fecc792a66730dcbbf0aa109f5f9ab
author Theodore Ts'o <tytso@mit.edu> Thu Nov 21 13:09:43 2019 -0500
committer Theodore Ts'o <tytso@mit.edu> Thu Dec 26 11:28:31 2019 -0500
tree 0e517f47ca1c5073481e0d8bfc8631f24388dbca
parent 878520ac45f9f698432d4276db3d9144b83931b6

ext4: simulate various I/O and checksum errors when reading metadata

This allows us to test various error handling code paths

Link: https://lore.kernel.org/r/20191209012317.59398-1-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/inode.c

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 23fa585..c3270aa 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4243,6 +4243,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
 	bh = sb_getblk(sb, block);
 	if (unlikely(!bh))
 		return -ENOMEM;
+	if (ext4_simulate_fail(sb, EXT4_SIM_INODE_EIO))
+		goto simulate_eio;
 	if (!buffer_uptodate(bh)) {
 		lock_buffer(bh);
 
@@ -4341,6 +4343,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 		blk_finish_plug(&plug);
 		wait_on_buffer(bh);
 		if (!buffer_uptodate(bh)) {
+		simulate_eio:
 			ext4_set_errno(inode->i_sb, EIO);
 			EXT4_ERROR_INODE_BLOCK(inode, block,
 					       "unable to read itable block");
@@ -4555,7 +4558,8 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
 					      sizeof(gen));
 	}
 
-	if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
+	if (!ext4_inode_csum_verify(inode, raw_inode, ei) ||
+	    ext4_simulate_fail(sb, EXT4_SIM_INODE_CRC)) {
 		ext4_set_errno(inode->i_sb, EFSBADCRC);
 		ext4_error_inode(inode, function, line, 0,
 				 "iget: checksum invalid");