diff mbox

[v2,04/15] initramfs: remove unnecessary symlinks processing shortcut

Message ID 1516850875-25066-5-git-send-email-takondra@cisco.com (mailing list archive)
State New, archived
Headers show

Commit Message

Taras Kondratiuk Jan. 25, 2018, 3:27 a.m. UTC
Special handling of symlinks in do_header() assumes that name and body
entries are sequential and reads them together. This shortcut has no
real performance benefits, but it complicates changes to the state
machine.

Make handling of symlinks more similar to a regular files. Store name
in name_buf and destination in symlink_buf.

Signed-off-by: Taras Kondratiuk <takondra@cisco.com>
---
 init/initramfs.c | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)
diff mbox

Patch

diff --git a/init/initramfs.c b/init/initramfs.c
index b6ee675e5cdb..d0ab7ad6ac05 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -266,16 +266,7 @@  static int __init do_header(void)
 	state = do_skip;
 	if (name_len <= 0 || name_len > PATH_MAX)
 		return 0;
-	if (S_ISLNK(mode)) {
-		if (body_len > PATH_MAX)
-			return 0;
-		collect = collected = symlink_buf;
-		remains = N_ALIGN(name_len) + body_len;
-		next_state = do_symlink;
-		state = do_collect;
-		return 0;
-	}
-	if (S_ISREG(mode) || !body_len)
+	if (S_ISREG(mode) || S_ISLNK(mode) || !body_len)
 		read_into(name_buf, N_ALIGN(name_len), do_name);
 	return 0;
 }
@@ -372,6 +363,11 @@  static int __init do_name(void)
 			sys_chmod(collected, mode);
 			do_utime(collected, mtime);
 		}
+	} else if (S_ISLNK(mode)) {
+		if (body_len > PATH_MAX)
+			return 0;
+		memcpy_optional(name_buf, collected, N_ALIGN(name_len));
+		read_into(symlink_buf, body_len, do_symlink);
 	}
 	return 0;
 }
@@ -397,11 +393,12 @@  static int __init do_copy(void)
 
 static int __init do_symlink(void)
 {
-	collected[N_ALIGN(name_len) + body_len] = '\0';
-	clean_path(collected, 0);
-	sys_symlink(collected + N_ALIGN(name_len), collected);
-	sys_lchown(collected, uid, gid);
-	do_utime(collected, mtime);
+	memcpy_optional(symlink_buf, collected, body_len);
+	symlink_buf[body_len] = '\0';
+	clean_path(name_buf, 0);
+	sys_symlink(symlink_buf, name_buf);
+	sys_lchown(name_buf, uid, gid);
+	do_utime(name_buf, mtime);
 	state = do_skip;
 	next_state = do_reset;
 	return 0;
@@ -453,7 +450,7 @@  static char * __init unpack_to_rootfs(char *buf, unsigned long len)
 	static __initdata char msg_buf[64];
 
 	header_buf = kmalloc(110, GFP_KERNEL);
-	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
+	symlink_buf = kmalloc(PATH_MAX + 1, GFP_KERNEL);
 	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
 
 	if (!header_buf || !symlink_buf || !name_buf)