[PATCH 2/7] namei: clean up do_unlinkat retry logic
From: Dmitry Kadashev <hidden>
Date: 2021-07-12 12:37:16
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Moving the main logic to a helper function makes the whole thing much 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-=wh=cpt_tQCirzFZRPawRpbuFTZ2MxNpXiyUF+eBXF=+sw@mail.gmail.com/ (local) Signed-off-by: Dmitry Kadashev <redacted> --- fs/namei.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index ae6cde7dc91e..bb18b1adfea5 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -4091,7 +4091,8 @@ EXPORT_SYMBOL(vfs_unlink); * writeout happening, and we don't want to prevent access to the directory * while waiting on the I/O. */ -int do_unlinkat(int dfd, struct filename *name) +static int unlinkat_helper(int dfd, struct filename *name, + unsigned int lookup_flags) { int error; struct dentry *dentry;
@@ -4100,19 +4101,18 @@ int do_unlinkat(int dfd, struct filename *name) int type; struct inode *inode = NULL; struct inode *delegated_inode = NULL; - unsigned int lookup_flags = 0; -retry: + error = __filename_parentat(dfd, name, lookup_flags, &path, &last, &type); if (error) - goto exit1; + return error; error = -EISDIR; if (type != LAST_NORM) - goto exit2; + goto exit1; error = mnt_want_write(path.mnt); if (error) - goto exit2; + goto exit1; retry_deleg: inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT); dentry = __lookup_hash(&last, path.dentry, lookup_flags);
@@ -4129,11 +4129,11 @@ int do_unlinkat(int dfd, struct filename *name) ihold(inode); error = security_path_unlink(&path, dentry); if (error) - goto exit3; + goto exit2; mnt_userns = mnt_user_ns(path.mnt); error = vfs_unlink(mnt_userns, path.dentry->d_inode, dentry, &delegated_inode); -exit3: +exit2: dput(dentry); } inode_unlock(path.dentry->d_inode);
@@ -4146,15 +4146,8 @@ int do_unlinkat(int dfd, struct filename *name) goto retry_deleg; } mnt_drop_write(path.mnt); -exit2: - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - inode = NULL; - goto retry; - } exit1: - putname(name); + path_put(&path); return error; slashes:
@@ -4164,7 +4157,19 @@ int do_unlinkat(int dfd, struct filename *name) error = -EISDIR; else error = -ENOTDIR; - goto exit3; + goto exit2; +} + +int do_unlinkat(int dfd, struct filename *name) +{ + int error; + + error = unlinkat_helper(dfd, name, 0); + if (retry_estale(error, 0)) + error = unlinkat_helper(dfd, name, LOOKUP_REVAL); + + putname(name); + return error; } SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag)
--
2.30.2