[PATCH v2 2/5] 9p: Track the root fid with its own variable during lookups

From: Tyler Hicks
Date: Thu May 26 2022 - 20:00:39 EST


Improve readability by using a new variable when dealing with the root
fid. The root fid requires special handling in comparison to other fids
used during fid lookup.

Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
---
fs/9p/fid.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 5a469b79c1ee..dae276ca7f7a 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -152,7 +152,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
const unsigned char **wnames, *uname;
int i, n, l, clone, access;
struct v9fs_session_info *v9ses;
- struct p9_fid *fid, *old_fid;
+ struct p9_fid *fid, *root_fid, *old_fid;

v9ses = v9fs_dentry2v9ses(dentry);
access = v9ses->flags & V9FS_ACCESS_MASK;
@@ -178,8 +178,8 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
up_read(&v9ses->rename_sem);

/* start from the root and try to do a lookup */
- fid = v9fs_fid_find(dentry->d_sb->s_root, uid, any);
- if (!fid) {
+ root_fid = v9fs_fid_find(dentry->d_sb->s_root, uid, any);
+ if (!root_fid) {
/* the user is not attached to the fs yet */
if (access == V9FS_ACCESS_SINGLE)
return ERR_PTR(-EPERM);
@@ -189,17 +189,18 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
else
uname = v9ses->uname;

- fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
- v9ses->aname);
- if (IS_ERR(fid))
- return fid;
+ root_fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
+ v9ses->aname);
+ if (IS_ERR(root_fid))
+ return root_fid;

- refcount_inc(&fid->count);
- v9fs_fid_add(dentry->d_sb->s_root, fid);
+ refcount_inc(&root_fid->count);
+ v9fs_fid_add(dentry->d_sb->s_root, root_fid);
}
/* If we are root ourself just return that */
if (dentry->d_sb->s_root == dentry)
- return fid;
+ return root_fid;
+
/*
* Do a multipath walk with attached root.
* When walking parent we need to make sure we
@@ -211,7 +212,8 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
fid = ERR_PTR(n);
goto err_out;
}
- old_fid = fid;
+ fid = root_fid;
+ old_fid = root_fid;
clone = 1;
i = 0;
while (i < n) {
@@ -220,7 +222,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
* We need to hold rename lock when doing a multipath
* walk to ensure none of the patch component change
*/
- fid = p9_client_walk(fid, l, &wnames[i], clone);
+ fid = p9_client_walk(old_fid, l, &wnames[i], clone);
p9_client_clunk(old_fid);
if (IS_ERR(fid)) {
kfree(wnames);
--
2.25.1