[PATCH 39/39] vfs: remove open_flags from d_real()
From: Miklos Szeredi
Date: Tue May 29 2018 - 11:04:13 EST
Opening regular files on overlayfs is now handled via ovl_open(). Remove
the now unused "open_flags" argument from d_op->d_real() and the d_real()
helper.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
Documentation/filesystems/Locking | 3 +--
Documentation/filesystems/vfs.txt | 16 ++++------------
fs/overlayfs/super.c | 36 +++---------------------------------
include/linux/dcache.h | 11 ++++-------
include/linux/fs.h | 2 +-
5 files changed, 13 insertions(+), 55 deletions(-)
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index a4afe96f0112..e1d7e43d302c 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -21,8 +21,7 @@ prototypes:
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
struct vfsmount *(*d_automount)(struct path *path);
int (*d_manage)(const struct path *, bool);
- struct dentry *(*d_real)(struct dentry *, const struct inode *,
- unsigned int);
+ struct dentry *(*d_real)(struct dentry *, const struct inode *);
locking rules:
rename_lock ->d_lock may block rcu-walk
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index af54d3651ff8..8b03c5e675bf 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -990,8 +990,7 @@ struct dentry_operations {
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
int (*d_manage)(const struct path *, bool);
- struct dentry *(*d_real)(struct dentry *, const struct inode *,
- unsigned int);
+ struct dentry *(*d_real)(struct dentry *, const struct inode *);
};
d_revalidate: called when the VFS needs to revalidate a dentry. This
@@ -1125,22 +1124,15 @@ struct dentry_operations {
dentry being transited from.
d_real: overlay/union type filesystems implement this method to return one of
- the underlying dentries hidden by the overlay. It is used in three
+ the underlying dentries hidden by the overlay. It is used in two
different modes:
- Called from open it may need to copy-up the file depending on the
- supplied open flags. This mode is selected with a non-zero flags
- argument. In this mode the d_real method can return an error.
-
Called from file_dentry() it returns the real dentry matching the inode
argument. The real dentry may be from a lower layer already copied up,
but still referenced from the file. This mode is selected with a
- non-NULL inode argument. This will always succeed.
-
- With NULL inode and zero flags the topmost real underlying dentry is
- returned. This will always succeed.
+ non-NULL inode argument.
- This method is never called with both non-NULL inode and non-zero flags.
+ With NULL inode the topmost real underlying dentry is returned.
Each dentry has a pointer to its parent dentry, as well as a hash list
of child dentries. Child dentries are basically like files in a
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index d7df69e5b674..cd5c82f105d6 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -80,28 +80,10 @@ static void ovl_dentry_release(struct dentry *dentry)
}
}
-static int ovl_check_append_only(struct inode *inode, int flag)
-{
- /*
- * This test was moot in vfs may_open() because overlay inode does
- * not have the S_APPEND flag, so re-check on real upper inode
- */
- if (IS_APPEND(inode)) {
- if ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND))
- return -EPERM;
- if (flag & O_TRUNC)
- return -EPERM;
- }
-
- return 0;
-}
-
static struct dentry *ovl_d_real(struct dentry *dentry,
- const struct inode *inode,
- unsigned int open_flags)
+ const struct inode *inode)
{
struct dentry *real;
- int err;
/* It's an overlay file */
if (inode && d_inode(dentry) == inode)
@@ -113,28 +95,16 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
goto bug;
}
- if (open_flags) {
- err = ovl_open_maybe_copy_up(dentry, open_flags);
- if (err)
- return ERR_PTR(err);
- }
-
real = ovl_dentry_upper(dentry);
- if (real && (!inode || inode == d_inode(real))) {
- if (!inode) {
- err = ovl_check_append_only(d_inode(real), open_flags);
- if (err)
- return ERR_PTR(err);
- }
+ if (real && (!inode || inode == d_inode(real)))
return real;
- }
real = ovl_dentry_lower(dentry);
if (!real)
goto bug;
/* Handle recursion */
- real = d_real(real, inode, open_flags);
+ real = d_real(real, inode);
if (!inode || inode == d_inode(real))
return real;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 8fe4efa94af6..78cea80423a3 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -145,8 +145,7 @@ struct dentry_operations {
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
int (*d_manage)(const struct path *, bool);
- struct dentry *(*d_real)(struct dentry *, const struct inode *,
- unsigned int);
+ struct dentry *(*d_real)(struct dentry *, const struct inode *);
} ____cacheline_aligned;
/*
@@ -568,7 +567,6 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
* d_real - Return the real dentry
* @dentry: the dentry to query
* @inode: inode to select the dentry from multiple layers (can be NULL)
- * @flags: open flags to control copy-up behavior
*
* If dentry is on a union/overlay, then return the underlying, real dentry.
* Otherwise return the dentry itself.
@@ -576,11 +574,10 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
* See also: Documentation/filesystems/vfs.txt
*/
static inline struct dentry *d_real(struct dentry *dentry,
- const struct inode *inode,
- unsigned int flags)
+ const struct inode *inode)
{
if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
- return dentry->d_op->d_real(dentry, inode, flags);
+ return dentry->d_op->d_real(dentry, inode);
else
return dentry;
}
@@ -595,7 +592,7 @@ static inline struct dentry *d_real(struct dentry *dentry,
static inline struct inode *d_real_inode(const struct dentry *dentry)
{
/* This usage of d_real() results in const dentry */
- return d_backing_inode(d_real((struct dentry *) dentry, NULL, 0));
+ return d_backing_inode(d_real((struct dentry *) dentry, NULL));
}
struct name_snapshot {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7471a4208fdc..eb4c189d34ba 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1234,7 +1234,7 @@ static inline struct inode *file_inode(const struct file *f)
static inline struct dentry *file_dentry(const struct file *file)
{
- return d_real(file->f_path.dentry, file_inode(file), 0);
+ return d_real(file->f_path.dentry, file_inode(file));
}
static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
--
2.14.3