[PATCH v4 14/17] vfs: fix renameat to retry on ESTALE errors
From: Jeff Layton <hidden>
Date: 2012-07-26 11:55:17
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
...as always, rename is the messiest of the bunch. We have to track whether to retry or not via a separate flag since the error handling is already quite complex. Signed-off-by: Jeff Layton <redacted> --- fs/namei.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 65e5177..7cf5e91 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -3699,12 +3699,25 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, char *from; char *to; int error; + unsigned int try = 0; + bool should_retry = false; + unsigned int lookup_flags = LOOKUP_PARENT; - error = user_path_parent(olddfd, oldname, &oldnd, &from); - if (error) + from = getname(oldname); + if (IS_ERR(from)) + return PTR_ERR(from); + + to = getname(newname); + if (IS_ERR(to)) { + error = PTR_ERR(to); goto exit; + } +retry: + error = do_path_lookup(olddfd, from, lookup_flags, &oldnd); + if (error) + goto exit0; - error = user_path_parent(newdfd, newname, &newnd, &to); + error = do_path_lookup(newdfd, to, lookup_flags, &newnd); if (error) goto exit1;
@@ -3773,13 +3786,21 @@ exit4: dput(old_dentry); exit3: unlock_rename(new_dir, old_dir); + if (retry_estale(error, try++)) + should_retry = true; exit2: path_put(&newnd.path); - putname(to); exit1: path_put(&oldnd.path); - putname(from); + if (should_retry) { + should_retry = false; + lookup_flags |= LOOKUP_REVAL; + goto retry; + } +exit0: + putname(to); exit: + putname(from); return error; }
--
1.7.11.2