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authorMiklos Szeredi <mszeredi@redhat.com>2016-06-30 08:53:27 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2016-06-30 08:53:27 +0200
commit2d902671ce1cd98cdc88d78c481889a1b2996101 (patch)
tree48c4bc8f90ee3209b7fba9b70169e8528b781eaa /fs/overlayfs
parent4c2e07c6a29e0129e975727b9f57eede813eea85 (diff)
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>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/inode.c31
-rw-r--r--fs/overlayfs/overlayfs.h2
-rw-r--r--fs/overlayfs/super.c20
3 files changed, 25 insertions, 28 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 1dbeab6cf96e..e08cd94d7b26 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -325,36 +325,25 @@ static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
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 4bd9b5ba8f42..6b9fd25c5ad4 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -179,7 +179,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
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 ce02f46029da..035c176edf00 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -304,7 +304,9 @@ static void ovl_dentry_release(struct dentry *dentry)
}
}
-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 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
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 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
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 int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
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,