[RFC][PATCH v3 08/55] lookup_open(): saner calling conventions (return dentry on success)

Al Viro
2020-03-01T21:56:00Z

same story as for atomic_open() in the previous commit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 44 +++++++++++++++++++-------------------------
1 file changed, 19 insertions(+), 25 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 5f8b791a6d6e..4946d006ba20 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3157,10 +3157,9 @@ static struct dentry *atomic_open(struct nameidata *nd, struct dentry *dentry,
*
* An error code is returned on failure.
*/
-static int lookup_open(struct nameidata *nd, struct path *path,
- struct file *file,
- const struct open_flags *op,
- bool got_write)
+static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
+ const struct open_flags *op,
+ bool got_write)
{
struct dentry *dir = nd->path.dentry;
struct inode *dir_inode = dir->d_inode;
@@ -3171,7 +3170,7 @@ static int lookup_open(struct nameidata *nd, struct path *path,
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);

if (unlikely(IS_DEADDIR(dir_inode)))
- return -ENOENT;
+ return ERR_PTR(-ENOENT);

file->f_mode &= ~FMODE_CREATED;
dentry = d_lookup(dir, &nd->last);
@@ -3179,7 +3178,7 @@ static int lookup_open(struct nameidata *nd, struct path *path,
if (!dentry) {
dentry = d_alloc_parallel(dir, &nd->last, &wq);
if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ return dentry;
}
if (d_in_lookup(dentry))
break;
@@ -3195,7 +3194,7 @@ static int lookup_open(struct nameidata *nd, struct path *path,
}
if (dentry->d_inode) {
/* Cached positive dentry: will open in f_op->open */
- goto out_no_open;
+ return dentry;
}

/*
@@ -3236,18 +3235,10 @@ static int lookup_open(struct nameidata *nd, struct path *path,
if (dir_inode->i_op->atomic_open) {
dentry = atomic_open(nd, dentry, file, op, open_flag, mode);
if (IS_ERR(dentry)) {
- error = PTR_ERR(dentry);
- if (unlikely(error == -ENOENT) && create_error)
- error = create_error;
- return error;
+ if (dentry == ERR_PTR(-ENOENT) && create_error)
+ dentry = ERR_PTR(create_error);
}
- if (file->f_mode & FMODE_OPENED) {
- dput(dentry);
- return 0;
- }
- path->mnt = nd->path.mnt;
- path->dentry = dentry;
- return 0;
+ return dentry;
}

no_open:
@@ -3283,14 +3274,11 @@ static int lookup_open(struct nameidata *nd, struct path *path,
error = create_error;
goto out_dput;
}
-out_no_open:
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 0;
+ return dentry;

out_dput:
dput(dentry);
- return error;
+ return ERR_PTR(error);
}

/*
@@ -3309,6 +3297,7 @@ static int do_last(struct nameidata *nd,
unsigned seq;
struct inode *inode;
struct path path;
+ struct dentry *dentry;
int error;

nd->flags &= ~LOOKUP_PARENT;
@@ -3365,14 +3354,18 @@ static int do_last(struct nameidata *nd,
inode_lock(dir->d_inode);
else
inode_lock_shared(dir->d_inode);
- error = lookup_open(nd, &path, file, op, got_write);
+ dentry = lookup_open(nd, file, op, got_write);
if (open_flag & O_CREAT)
inode_unlock(dir->d_inode);
else
inode_unlock_shared(dir->d_inode);

- if (error)
+ if (IS_ERR(dentry)) {
+ error = PTR_ERR(dentry);
goto out;
+ }
+ path.mnt = nd->path.mnt;
+ path.dentry = dentry;

if (file->f_mode & FMODE_OPENED) {
if ((file->f_mode & FMODE_CREATED) ||
@@ -3380,6 +3373,7 @@ static int do_last(struct nameidata *nd,
will_truncate = false;

audit_inode(nd->name, file->f_path.dentry, 0);
+ dput(dentry);
goto opened;
}

--
2.11.0