[PATCH 09/14] namei: prepare do_symlinkat for refactoring
From: Dmitry Kadashev <hidden>
Date: 2021-07-15 10:36:25
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
This is just a preparation for the move of the main symlinkat logic to a separate function to make the logic easier to follow. This change contains the flow changes so that the actual change to move the main logic to a separate function does no change the flow at all. There are 3 changes to the flow here: 1. IS_ERR(from) check is repeated on ESTALE retry now. It's OK to do since the call is trivial (and ESTALE retry is a slow path); 2. Just like the similar patches for rmdir and others a few commits before, previously on filename_create() error the function used to exit immediately, and now it will check the return code to see if ESTALE retry is appropriate. The filename_create() does its own retries on ESTALE (at least via filename_parentat() used inside), but this extra check should be completely fine. 3. The retry_estale() check is wrapped in unlikely(). Some other places already have that and overall it seems to make sense Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <redacted> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/io-uring/CAHk-=wiG+sN+2zSoAOggKCGue2kOJvw3rQySvQXsZstRQFTN+g@mail.gmail.com/ (local) Link: https://lore.kernel.org/io-uring/CAHk-=whH4msnFkj=iYZ9NDmZEAiZKM+vii803M8gnEwEsF1-Yg@mail.gmail.com/ (local) Signed-off-by: Dmitry Kadashev <redacted> --- fs/namei.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index f7cde1543b47..c4d75c94adce 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -4241,15 +4241,15 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to) struct path path; unsigned int lookup_flags = 0; +retry: if (IS_ERR(from)) { error = PTR_ERR(from); - goto out_putnames; + goto out; } -retry: dentry = __filename_create(newdfd, to, &path, lookup_flags); error = PTR_ERR(dentry); if (IS_ERR(dentry)) - goto out_putnames; + goto out; error = security_path_symlink(&path, dentry, from->name); if (!error) {
@@ -4260,11 +4260,11 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to) from->name); } done_path_create(&path, dentry); - if (retry_estale(error, lookup_flags)) { +out: + if (unlikely(retry_estale(error, lookup_flags))) { lookup_flags |= LOOKUP_REVAL; goto retry; } -out_putnames: putname(to); putname(from); return error;
--
2.30.2