[PATCH 10/12] ext4: add symlink block I/O fault injection

[Zhang Yi <yi.zhang@xxxxxxxxxx>]

Add I/O fault injection when reading symlink block, user could specify
which inode to inject error. It will return -EIO immediately instead of
submitting I/O.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/ext4/ext4.h    | 2 ++
 fs/ext4/symlink.c | 4 ++++
 fs/ext4/sysfs.c   | 1 +
 3 files changed, 7 insertions(+)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 94894daef595..813127cfd3c0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1525,6 +1525,7 @@ enum ext4_fault_bits {
 	EXT4_FAULT_EXTENT_EIO,		/* extent block */
 	EXT4_FAULT_DIRBLOCK_EIO,	/* directory block */
 	EXT4_FAULT_XATTR_EIO,		/* xattr block */
+	EXT4_FAULT_SYMLINK_EIO,		/* symlink block */
 	EXT4_FAULT_MAX
 };
 
@@ -1630,6 +1631,7 @@ EXT4_FAULT_INODE_FN(INODE_EIO, inode_io, -EIO)
 EXT4_FAULT_INODE_PBLOCK_FN(EXTENT_EIO, extent_io, -EIO)
 EXT4_FAULT_INODE_LBLOCK_FN(DIRBLOCK_EIO, dirblock_io, -EIO)
 EXT4_FAULT_INODE_FN(XATTR_EIO, xattr_io, -EIO)
+EXT4_FAULT_INODE_FN(SYMLINK_EIO, symlink_io, -EIO)
 
 /*
  * fourth extended-fs super-block data in memory
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 3d3ed3c38f56..5392e707418e 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -39,6 +39,8 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
 		caddr = EXT4_I(inode)->i_data;
 		max_size = sizeof(EXT4_I(inode)->i_data);
 	} else {
+		if (ext4_fault_symlink_io(inode->i_sb, inode->i_ino))
+			return ERR_PTR(-EIO);
 		bh = ext4_bread(NULL, inode, 0, 0);
 		if (IS_ERR(bh))
 			return ERR_CAST(bh);
@@ -97,6 +99,8 @@ static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
 		if (!bh || !ext4_buffer_uptodate(bh))
 			return ERR_PTR(-ECHILD);
 	} else {
+		if (ext4_fault_symlink_io(inode->i_sb, inode->i_ino))
+			return ERR_PTR(-EIO);
 		bh = ext4_bread(NULL, inode, 0, 0);
 		if (IS_ERR(bh))
 			return ERR_CAST(bh);
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index f7f8882037a5..aca91ab5b506 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -584,6 +584,7 @@ char *ext4_fault_names[EXT4_FAULT_MAX] = {
 	"extent_block_eio",		/* EXT4_FAULT_EXTENT_EIO */
 	"dir_block_eio",		/* EXT4_FAULT_DIRBLOCK_EIO */
 	"xattr_block_eio",		/* EXT4_FAULT_XATTR_EIO */
+	"symlink_block_eio",		/* EXT4_FAULT_SYMLINK_EIO */
 };
 
 static int ext4_fault_available_show(struct seq_file *m, void *v)
-- 
2.31.1