vfs: merge .d_select_inode() into .d_real()
The two methods essentially do the same: find the real dentry/inode
belonging to an overlay dentry. The difference is in the usage:
vfs_open() uses ->d_select_inode() and expects the function to perform
copy-up if necessary based on the open flags argument.
file_dentry() uses ->d_real() passing in the overlay dentry as well as the
underlying inode.
vfs_rename() uses ->d_select_inode() but passes zero flags. ->d_real()
with a zero inode would have worked just as well here.
This patch merges the functionality of ->d_select_inode() into ->d_real()
by adding an 'open_flags' argument to the latter.
[Al Viro] Make the signature of d_real() match that of ->d_real() again.
And constify the inode argument, while we are at it.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/dcache.c b/fs/dcache.c
index d6847d7..5405b89 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1729,7 +1729,6 @@
DCACHE_OP_REVALIDATE |
DCACHE_OP_WEAK_REVALIDATE |
DCACHE_OP_DELETE |
- DCACHE_OP_SELECT_INODE |
DCACHE_OP_REAL));
dentry->d_op = op;
if (!op)
@@ -1746,8 +1745,6 @@
dentry->d_flags |= DCACHE_OP_DELETE;
if (op->d_prune)
dentry->d_flags |= DCACHE_OP_PRUNE;
- if (op->d_select_inode)
- dentry->d_flags |= DCACHE_OP_SELECT_INODE;
if (op->d_real)
dentry->d_flags |= DCACHE_OP_REAL;
diff --git a/fs/namei.c b/fs/namei.c
index 70580ab..bb7a2e0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4328,7 +4328,7 @@
* Check source == target.
* On overlayfs need to look at underlying inodes.
*/
- if (vfs_select_inode(old_dentry, 0) == vfs_select_inode(new_dentry, 0))
+ if (d_real_inode(old_dentry) == d_real_inode(new_dentry))
return 0;
error = may_delete(old_dir, old_dentry, is_dir);
diff --git a/fs/open.c b/fs/open.c
index 93ae3cd..bf66cf1 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -840,13 +840,13 @@
int vfs_open(const struct path *path, struct file *file,
const struct cred *cred)
{
- struct inode *inode = vfs_select_inode(path->dentry, file->f_flags);
+ struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags);
- if (IS_ERR(inode))
- return PTR_ERR(inode);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
file->f_path = *path;
- return do_dentry_open(file, inode, NULL, cred);
+ return do_dentry_open(file, d_backing_inode(dentry), NULL, cred);
}
struct file *dentry_open(const struct path *path, int flags,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 1dbeab6..e08cd94 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -325,36 +325,25 @@
return true;
}
-struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
+int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
{
- int err;
+ int err = 0;
struct path realpath;
enum ovl_path_type type;
- if (d_is_dir(dentry))
- return d_backing_inode(dentry);
-
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
err = ovl_want_write(dentry);
- if (err)
- return ERR_PTR(err);
-
- if (file_flags & O_TRUNC)
- err = ovl_copy_up_truncate(dentry);
- else
- err = ovl_copy_up(dentry);
- ovl_drop_write(dentry);
- if (err)
- return ERR_PTR(err);
-
- ovl_path_upper(dentry, &realpath);
+ if (!err) {
+ if (file_flags & O_TRUNC)
+ err = ovl_copy_up_truncate(dentry);
+ else
+ err = ovl_copy_up(dentry);
+ ovl_drop_write(dentry);
+ }
}
- if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
- return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);
-
- return d_backing_inode(realpath.dentry);
+ return err;
}
static const struct inode_operations ovl_file_inode_operations = {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 4bd9b5b..6b9fd25 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -179,7 +179,7 @@
const char *name, void *value, size_t size);
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
int ovl_removexattr(struct dentry *dentry, const char *name);
-struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags);
+int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
struct ovl_entry *oe);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index ce02f46..035c176 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -304,7 +304,9 @@
}
}
-static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
+static struct dentry *ovl_d_real(struct dentry *dentry,
+ const struct inode *inode,
+ unsigned int open_flags)
{
struct dentry *real;
@@ -314,6 +316,16 @@
goto bug;
}
+ if (d_is_negative(dentry))
+ return dentry;
+
+ if (open_flags) {
+ int 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)))
return real;
@@ -326,9 +338,7 @@
return real;
/* Handle recursion */
- if (real->d_flags & DCACHE_OP_REAL)
- return real->d_op->d_real(real, inode);
-
+ return d_real(real, inode, open_flags);
bug:
WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry,
inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0);
@@ -378,13 +388,11 @@
static const struct dentry_operations ovl_dentry_operations = {
.d_release = ovl_dentry_release,
- .d_select_inode = ovl_d_select_inode,
.d_real = ovl_d_real,
};
static const struct dentry_operations ovl_reval_dentry_operations = {
.d_release = ovl_dentry_release,
- .d_select_inode = ovl_d_select_inode,
.d_real = ovl_d_real,
.d_revalidate = ovl_dentry_revalidate,
.d_weak_revalidate = ovl_dentry_weak_revalidate,
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index f53fa05..45b22de 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -139,8 +139,7 @@
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
int (*d_manage)(struct dentry *, bool);
- struct inode *(*d_select_inode)(struct dentry *, unsigned);
- struct dentry *(*d_real)(struct dentry *, struct inode *);
+ struct dentry *(*d_real)(struct dentry *, const struct inode *, unsigned int);
} ____cacheline_aligned;
/*
@@ -206,10 +205,8 @@
#define DCACHE_MAY_FREE 0x00800000
#define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
-#define DCACHE_OP_SELECT_INODE 0x02000000 /* Unioned entry: dcache op selects inode */
-
-#define DCACHE_ENCRYPTED_WITH_KEY 0x04000000 /* dir is encrypted with a valid key */
-#define DCACHE_OP_REAL 0x08000000
+#define DCACHE_ENCRYPTED_WITH_KEY 0x02000000 /* dir is encrypted with a valid key */
+#define DCACHE_OP_REAL 0x04000000
#define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */
#define DCACHE_DENTRY_CURSOR 0x20000000
@@ -557,25 +554,16 @@
return upper;
}
-static inline struct dentry *d_real(struct dentry *dentry)
+static inline struct dentry *d_real(struct dentry *dentry,
+ const struct inode *inode,
+ unsigned int flags)
{
if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
- return dentry->d_op->d_real(dentry, NULL);
+ return dentry->d_op->d_real(dentry, inode, flags);
else
return dentry;
}
-static inline struct inode *vfs_select_inode(struct dentry *dentry,
- unsigned open_flags)
-{
- struct inode *inode = d_inode(dentry);
-
- if (inode && unlikely(dentry->d_flags & DCACHE_OP_SELECT_INODE))
- inode = dentry->d_op->d_select_inode(dentry, open_flags);
-
- return inode;
-}
-
/**
* d_real_inode - Return the real inode
* @dentry: The dentry to query
@@ -585,7 +573,7 @@
*/
static inline struct inode *d_real_inode(struct dentry *dentry)
{
- return d_backing_inode(d_real(dentry));
+ return d_backing_inode(d_real(dentry, NULL, 0));
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index dd28814..bacc073 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1272,12 +1272,7 @@
static inline struct dentry *file_dentry(const struct file *file)
{
- struct dentry *dentry = file->f_path.dentry;
-
- if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
- return dentry->d_op->d_real(dentry, file_inode(file));
- else
- return dentry;
+ return d_real(file->f_path.dentry, file_inode(file), 0);
}
static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)