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From:   Zhang Yi <yi.zhang@huawei.com>
To:     <linux-ext4@vger.kernel.org>
CC:     <tytso@mit.edu>, <adilger.kernel@dilger.ca>, <jack@suse.cz>,
        <yi.zhang@huawei.com>, <yukuai3@huawei.com>
Subject: [PATCH 06/12] ext4: add extent block I/O fault injection
Date:   Tue, 8 Nov 2022 22:46:11 +0800
Message-ID: <20221108144617.4159381-7-yi.zhang@huawei.com>
In-Reply-To: <20221108144617.4159381-1-yi.zhang@huawei.com>
References: <20221108144617.4159381-1-yi.zhang@huawei.com>
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Add inode extent block reading I/O fault injection, we can specify the
inode and physical metadata block to inject, it will return -EIO
immediately instead of submitting I/O.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/ext4.h    | 2 ++
 fs/ext4/extents.c | 5 +++++
 fs/ext4/sysfs.c   | 1 +
 3 files changed, 8 insertions(+)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 29a819a186f7..9c1dcbed59e6 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1522,6 +1522,7 @@ enum ext4_fault_bits {
 	EXT4_FAULT_IBITMAP_EIO,		/* inode bitmap block */
 	EXT4_FAULT_BBITMAP_EIO,		/* block bitmap block */
 	EXT4_FAULT_INODE_EIO,		/* inode */
+	EXT4_FAULT_EXTENT_EIO,		/* extent block */
 	EXT4_FAULT_MAX
 };
 
@@ -1624,6 +1625,7 @@ EXT4_FAULT_INODE_FN(XATTR_CSUM, xattr_csum, 1)
 EXT4_FAULT_GRP_FN(IBITMAP_EIO, inode_bitmap_io, -EIO)
 EXT4_FAULT_GRP_FN(BBITMAP_EIO, block_bitmap_io, -EIO)
 EXT4_FAULT_INODE_FN(INODE_EIO, inode_io, -EIO)
+EXT4_FAULT_INODE_PBLOCK_FN(EXTENT_EIO, extent_io, -EIO)
 
 /*
  * fourth extended-fs super-block data in memory
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 0d07e5cf4dab..504ed35ffeaf 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -566,6 +566,11 @@ __read_extent_tree_block(const char *function, unsigned int line,
 
 	if (!bh_uptodate_or_lock(bh)) {
 		trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
+		err = ext4_fault_extent_io(inode->i_sb, inode->i_ino, pblk);
+		if (err) {
+			unlock_buffer(bh);
+			goto errout;
+		}
 		err = ext4_read_bh(bh, 0, NULL);
 		if (err < 0)
 			goto errout;
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 9c6d9a212d47..bad4885399dd 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -581,6 +581,7 @@ char *ext4_fault_names[EXT4_FAULT_MAX] = {
 	"inode_bitmap_eio",		/* EXT4_FAULT_IBITMAP_EIO */
 	"block_bitmap_eio",		/* EXT4_FAULT_BBITMAP_EIO */
 	"inode_eio",			/* EXT4_FAULT_INODE_EIO */
+	"extent_block_eio",		/* EXT4_FAULT_EXTENT_EIO */
 };
 
 static int ext4_fault_available_show(struct seq_file *m, void *v)
-- 
2.31.1