[RFC][PATCH v2 10/34] handle_mounts(): pass dentry in, turn path into a pure out argument

Al Viro
2020-02-23T01:19:20Z

All callers are equivalent to
path->dentry = dentry;
path->mnt = nd->path.mnt;
err = handle_mounts(path, ...)
Pass dentry as an explicit argument, fill *path in handle_mounts()
itself.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 37 ++++++++++++++++++-------------------
1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index f26af0559abf..033f91a72bb5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1385,11 +1385,15 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
!(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT);
}

-static inline int handle_mounts(struct path *path, struct nameidata *nd,
- struct inode **inode, unsigned int *seqp)
+static inline int handle_mounts(struct nameidata *nd, struct dentry *dentry,
+ struct path *path, struct inode **inode,
+ unsigned int *seqp)
{
- int ret = follow_managed(path, nd);
+ int ret;

+ path->mnt = nd->path.mnt;
+ path->dentry = dentry;
+ ret = follow_managed(path, nd);
if (likely(ret >= 0)) {
*inode = d_backing_inode(path->dentry);
*seqp = 0; /* out of RCU mode, so the value doesn't matter */
@@ -1685,10 +1689,7 @@ static int lookup_fast(struct nameidata *nd,
dput(dentry);
return status;
}
-
- path->mnt = mnt;
- path->dentry = dentry;
- return handle_mounts(path, nd, inode, seqp);
+ return handle_mounts(nd, dentry, path, inode, seqp);
}

/* Fast lookup failed, do it the slow way */
@@ -1859,6 +1860,7 @@ static inline int step_into(struct nameidata *nd, struct path *path,
static int walk_component(struct nameidata *nd, int flags)
{
struct path path;
+ struct dentry *dentry;
struct inode *inode;
unsigned seq;
int err;
@@ -1877,13 +1879,11 @@ static int walk_component(struct nameidata *nd, int flags)
if (unlikely(err <= 0)) {
if (err < 0)
return err;
- path.dentry = lookup_slow(&nd->last, nd->path.dentry,
- nd->flags);
- if (IS_ERR(path.dentry))
- return PTR_ERR(path.dentry);
+ dentry = lookup_slow(&nd->last, nd->path.dentry, nd->flags);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);

- path.mnt = nd->path.mnt;
- err = handle_mounts(&path, nd, &inode, &seq);
+ err = handle_mounts(nd, dentry, &path, &inode, &seq);
if (unlikely(err < 0))
return err;
}
@@ -2355,7 +2355,7 @@ static inline int lookup_last(struct nameidata *nd)

static int handle_lookup_down(struct nameidata *nd)
{
- struct path path = nd->path;
+ struct path path;
struct inode *inode = nd->inode;
unsigned seq = nd->seq;
int err;
@@ -2366,11 +2366,12 @@ static int handle_lookup_down(struct nameidata *nd)
* at the very beginning of walk, so we lose nothing
* if we simply redo everything in non-RCU mode
*/
+ path = nd->path;
if (unlikely(!__follow_mount_rcu(nd, &path, &inode, &seq)))
return -ECHILD;
} else {
- dget(path.dentry);
- err = handle_mounts(&path, nd, &inode, &seq);
+ dget(nd->path.dentry);
+ err = handle_mounts(nd, nd->path.dentry, &path, &inode, &seq);
if (unlikely(err < 0))
return err;
}
@@ -3395,9 +3396,7 @@ static int do_last(struct nameidata *nd,
got_write = false;
}

- path.mnt = nd->path.mnt;
- path.dentry = dentry;
- error = handle_mounts(&path, nd, &inode, &seq);
+ error = handle_mounts(nd, dentry, &path, &inode, &seq);
if (unlikely(error < 0))
return error;
finish_lookup:
--
2.11.0