ext4: save all error info in save_error_info() and drop ext4_set_errno()

Using a separate function, ext4_set_errno() to set the errno is
problematic because it doesn't do the right thing once
s_last_error_errorcode is non-zero.  It's also less racy to set all of
the error information all at once.  (Also, as a bonus, it shrinks code
size slightly.)

Link: https://lore.kernel.org/r/20200329020404.686965-1-tytso@mit.edu
Fixes: 878520ac45f9 ("ext4: save the error code which triggered...")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5f0a7589..a8aca47 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -160,9 +160,9 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 			set_buffer_verified(bh);
 		else {
-			ext4_set_errno(inode->i_sb, EFSBADCRC);
-			ext4_error_inode(inode, func, line, block,
-					 "Directory index failed checksum");
+			ext4_error_inode_err(inode, func, line, block,
+					     EFSBADCRC,
+					     "Directory index failed checksum");
 			brelse(bh);
 			return ERR_PTR(-EFSBADCRC);
 		}
@@ -172,9 +172,9 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
 		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
 			set_buffer_verified(bh);
 		else {
-			ext4_set_errno(inode->i_sb, EFSBADCRC);
-			ext4_error_inode(inode, func, line, block,
-					 "Directory block failed checksum");
+			ext4_error_inode_err(inode, func, line, block,
+					     EFSBADCRC,
+					     "Directory block failed checksum");
 			brelse(bh);
 			return ERR_PTR(-EFSBADCRC);
 		}
@@ -1532,9 +1532,9 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 			goto next;
 		wait_on_buffer(bh);
 		if (!buffer_uptodate(bh)) {
-			ext4_set_errno(sb, EIO);
-			EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
-					 (unsigned long) block);
+			EXT4_ERROR_INODE_ERR(dir, EIO,
+					     "reading directory lblock %lu",
+					     (unsigned long) block);
 			brelse(bh);
 			ret = ERR_PTR(-EIO);
 			goto cleanup_and_exit;
@@ -1543,9 +1543,9 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 		    !is_dx_internal_node(dir, block,
 					 (struct ext4_dir_entry *)bh->b_data) &&
 		    !ext4_dirblock_csum_verify(dir, bh)) {
-			ext4_set_errno(sb, EFSBADCRC);
-			EXT4_ERROR_INODE(dir, "checksumming directory "
-					 "block %lu", (unsigned long)block);
+			EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
+					     "checksumming directory "
+					     "block %lu", (unsigned long)block);
 			brelse(bh);
 			ret = ERR_PTR(-EFSBADCRC);
 			goto cleanup_and_exit;