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authorAl Viro <viro@zeniv.linux.org.uk>2018-06-09 16:40:05 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2018-07-12 17:04:23 +0300
commitd93aa9d82aea80b80f225dbf9c7986df444d8106 (patch)
tree887b5626f375e6745e034e227eb0c583fbefad99
parentdbae8f2ca2f0586f4b80201c78ff0aed2a012ab5 (diff)
downloadlinux-d93aa9d82aea80b80f225dbf9c7986df444d8106.tar.xz
new wrapper: alloc_file_pseudo()
takes inode, vfsmount, name, O_... flags and file_operations and either returns a new struct file (in which case inode reference we held is consumed) or returns ERR_PTR(), in which case no refcounts are altered. converted aio_private_file() and sock_alloc_file() to it Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/aio.c20
-rw-r--r--fs/file_table.c27
-rw-r--r--include/linux/file.h3
-rw-r--r--net/socket.c28
4 files changed, 39 insertions, 39 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 9eea53887d6c..c3a8bac16374 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -215,9 +215,7 @@ static const struct address_space_operations aio_ctx_aops;
static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
{
- struct qstr this = QSTR_INIT("[aio]", 5);
struct file *file;
- struct path path;
struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
if (IS_ERR(inode))
return ERR_CAST(inode);
@@ -226,27 +224,17 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
inode->i_mapping->private_data = ctx;
inode->i_size = PAGE_SIZE * nr_pages;
- path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
- if (!path.dentry) {
- iput(inode);
- return ERR_PTR(-ENOMEM);
- }
- path.mnt = mntget(aio_mnt);
-
- d_instantiate(path.dentry, inode);
- file = alloc_file(&path, O_RDWR, &aio_ring_fops);
+ file = alloc_file_pseudo(inode, aio_mnt, "[aio]",
+ O_RDWR, &aio_ring_fops);
if (IS_ERR(file))
- path_put(&path);
+ iput(inode);
return file;
}
static struct dentry *aio_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- static const struct dentry_operations ops = {
- .d_dname = simple_dname,
- };
- struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, &ops,
+ struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, NULL,
AIO_RING_MAGIC);
if (!IS_ERR(root))
diff --git a/fs/file_table.c b/fs/file_table.c
index 9b70ed2bbc4e..6b3723909342 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -184,6 +184,33 @@ struct file *alloc_file(const struct path *path, int flags,
}
EXPORT_SYMBOL(alloc_file);
+struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
+ const char *name, int flags,
+ const struct file_operations *fops)
+{
+ static const struct dentry_operations anon_ops = {
+ .d_dname = simple_dname
+ };
+ struct qstr this = QSTR_INIT(name, strlen(name));
+ struct path path;
+ struct file *file;
+
+ path.dentry = d_alloc_pseudo(mnt->mnt_sb, &this);
+ if (!path.dentry)
+ return ERR_PTR(-ENOMEM);
+ if (!mnt->mnt_sb->s_d_op)
+ d_set_d_op(path.dentry, &anon_ops);
+ path.mnt = mntget(mnt);
+ d_instantiate(path.dentry, inode);
+ file = alloc_file(&path, flags, fops);
+ if (IS_ERR(file)) {
+ ihold(inode);
+ path_put(&path);
+ }
+ return file;
+}
+EXPORT_SYMBOL(alloc_file_pseudo);
+
/* the real guts of fput() - releasing the last reference to file
*/
static void __fput(struct file *file)
diff --git a/include/linux/file.h b/include/linux/file.h
index aed45d69811e..5b25388f2f79 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -17,9 +17,12 @@ extern void fput(struct file *);
struct file_operations;
struct vfsmount;
struct dentry;
+struct inode;
struct path;
extern struct file *alloc_file(const struct path *, int flags,
const struct file_operations *fop);
+extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
+ const char *, int flags, const struct file_operations *);
static inline void fput_light(struct file *file, int fput_needed)
{
diff --git a/net/socket.c b/net/socket.c
index 2cdbe8f71b7f..4cf3568caf9f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -391,33 +391,15 @@ static struct file_system_type sock_fs_type = {
struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
{
- struct qstr name = { .name = "" };
- struct path path;
struct file *file;
- if (dname) {
- name.name = dname;
- name.len = strlen(name.name);
- } else if (sock->sk) {
- name.name = sock->sk->sk_prot_creator->name;
- name.len = strlen(name.name);
- }
- path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
- if (unlikely(!path.dentry)) {
- sock_release(sock);
- return ERR_PTR(-ENOMEM);
- }
- path.mnt = mntget(sock_mnt);
-
- d_instantiate(path.dentry, SOCK_INODE(sock));
+ if (!dname)
+ dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
- file = alloc_file(&path, O_RDWR | (flags & O_NONBLOCK),
- &socket_file_ops);
+ file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
+ O_RDWR | (flags & O_NONBLOCK),
+ &socket_file_ops);
if (IS_ERR(file)) {
- /* drop dentry, keep inode for a bit */
- ihold(d_inode(path.dentry));
- path_put(&path);
- /* ... and now kill it properly */
sock_release(sock);
return file;
}