[PATCH v2 12/14] namei: clean up do_linkat retry logic
From: Dmitry Kadashev <hidden>
Date: 2021-07-15 10:46:08
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
No functional changes, just move the main logic to a helper function to make the whole thing easier to follow. 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-=wiE_JVny73KRZ6wuhL_5U0RRSmAw678_Cnkh3OHM8C7Jg@mail.gmail.com/ (local) Signed-off-by: Dmitry Kadashev <redacted> --- fs/namei.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 82cb6421b6df..b93e9623eb5d 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -4381,37 +4381,32 @@ EXPORT_SYMBOL(vfs_link); * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -int do_linkat(int olddfd, struct filename *old, int newdfd, - struct filename *new, int flags) +static int try_linkat(int olddfd, struct filename *old, int newdfd, + struct filename *new, int flags, unsigned int how) { struct user_namespace *mnt_userns; struct dentry *new_dentry; struct path old_path, new_path; struct inode *delegated_inode = NULL; - int how = 0; int error; retry: - if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) { - error = -EINVAL; - goto out_putnames; - } + if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; /* * To use null names we require CAP_DAC_READ_SEARCH * This ensures that not everyone will be able to create * handlink using the passed filedescriptor. */ - if (flags & AT_EMPTY_PATH && !capable(CAP_DAC_READ_SEARCH)) { - error = -ENOENT; - goto out_putnames; - } + if (flags & AT_EMPTY_PATH && !capable(CAP_DAC_READ_SEARCH)) + return -ENOENT; if (flags & AT_SYMLINK_FOLLOW) how |= LOOKUP_FOLLOW; error = __filename_lookup(olddfd, old, how, &old_path, NULL); if (error) - goto out_putnames; + return error; new_dentry = __filename_create(newdfd, new, &new_path, (how & LOOKUP_REVAL));
@@ -4442,14 +4437,20 @@ int do_linkat(int olddfd, struct filename *old, int newdfd, } out_putpath: path_put(&old_path); -out_putnames: - if (unlikely(retry_estale(error, how))) { - how |= LOOKUP_REVAL; - goto retry; - } + return error; +} + +int do_linkat(int olddfd, struct filename *old, int newdfd, + struct filename *new, int flags) +{ + int error; + + error = try_linkat(olddfd, old, newdfd, new, flags, 0); + if (unlikely(retry_estale(error, 0))) + error = try_linkat(olddfd, old, newdfd, new, flags, LOOKUP_REVAL); + putname(old); putname(new); - return error; }
--
2.30.2