[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/anon_inodes.c b/ap/os/linux/linux-3.4.x/fs/anon_inodes.c
new file mode 100644
index 0000000..28d39fb
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/anon_inodes.c
@@ -0,0 +1,247 @@
+/*
+ * fs/anon_inodes.c
+ *
+ * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
+ *
+ * Thanks to Arnd Bergmann for code review and suggestions.
+ * More changes for Thomas Gleixner suggestions.
+ *
+ */
+
+#include <linux/cred.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/magic.h>
+#include <linux/anon_inodes.h>
+
+#include <asm/uaccess.h>
+
+static struct vfsmount *anon_inode_mnt __read_mostly;
+static struct inode *anon_inode_inode;
+static const struct file_operations anon_inode_fops;
+
+/*
+ * anon_inodefs_dname() is called from d_path().
+ */
+static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+ return dynamic_dname(dentry, buffer, buflen, "anon_inode:%s",
+ dentry->d_name.name);
+}
+
+static const struct dentry_operations anon_inodefs_dentry_operations = {
+ .d_dname = anon_inodefs_dname,
+};
+
+/*
+ * nop .set_page_dirty method so that people can use .page_mkwrite on
+ * anon inodes.
+ */
+static int anon_set_page_dirty(struct page *page)
+{
+ return 0;
+};
+
+static const struct address_space_operations anon_aops = {
+ .set_page_dirty = anon_set_page_dirty,
+};
+
+/*
+ * A single inode exists for all anon_inode files. Contrary to pipes,
+ * anon_inode inodes have no associated per-instance data, so we need
+ * only allocate one of them.
+ */
+static struct inode *anon_inode_mkinode(struct super_block *s)
+{
+ struct inode *inode = new_inode_pseudo(s);
+
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ inode->i_ino = get_next_ino();
+ inode->i_fop = &anon_inode_fops;
+
+ inode->i_mapping->a_ops = &anon_aops;
+
+ /*
+ * Mark the inode dirty from the very beginning,
+ * that way it will never be moved to the dirty
+ * list because mark_inode_dirty() will think
+ * that it already _is_ on the dirty list.
+ */
+ inode->i_state = I_DIRTY;
+ inode->i_mode = S_IRUSR | S_IWUSR;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_flags |= S_PRIVATE;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ return inode;
+}
+
+static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ struct dentry *root;
+ root = mount_pseudo(fs_type, "anon_inode:", NULL,
+ &anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
+ if (!IS_ERR(root)) {
+ struct super_block *s = root->d_sb;
+ anon_inode_inode = anon_inode_mkinode(s);
+ if (IS_ERR(anon_inode_inode)) {
+ dput(root);
+ deactivate_locked_super(s);
+ root = ERR_CAST(anon_inode_inode);
+ }
+ }
+ return root;
+}
+
+static struct file_system_type anon_inode_fs_type = {
+ .name = "anon_inodefs",
+ .mount = anon_inodefs_mount,
+ .kill_sb = kill_anon_super,
+};
+
+/**
+ * anon_inode_getfile - creates a new file instance by hooking it up to an
+ * anonymous inode, and a dentry that describe the "class"
+ * of the file
+ *
+ * @name: [in] name of the "class" of the new file
+ * @fops: [in] file operations for the new file
+ * @priv: [in] private data for the new file (will be file's private_data)
+ * @flags: [in] flags
+ *
+ * Creates a new file by hooking it on a single inode. This is useful for files
+ * that do not need to have a full-fledged inode in order to operate correctly.
+ * All the files created with anon_inode_getfile() will share a single inode,
+ * hence saving memory and avoiding code duplication for the file/inode/dentry
+ * setup. Returns the newly created file* or an error pointer.
+ */
+struct file *anon_inode_getfile(const char *name,
+ const struct file_operations *fops,
+ void *priv, int flags)
+{
+ struct qstr this;
+ struct path path;
+ struct file *file;
+ int error;
+
+ if (IS_ERR(anon_inode_inode))
+ return ERR_PTR(-ENODEV);
+
+ if (fops->owner && !try_module_get(fops->owner))
+ return ERR_PTR(-ENOENT);
+
+ /*
+ * Link the inode to a directory entry by creating a unique name
+ * using the inode sequence number.
+ */
+ error = -ENOMEM;
+ this.name = name;
+ this.len = strlen(name);
+ this.hash = 0;
+ path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this);
+ if (!path.dentry)
+ goto err_module;
+
+ path.mnt = mntget(anon_inode_mnt);
+ /*
+ * We know the anon_inode inode count is always greater than zero,
+ * so ihold() is safe.
+ */
+ ihold(anon_inode_inode);
+
+ d_instantiate(path.dentry, anon_inode_inode);
+
+ error = -ENFILE;
+ file = alloc_file(&path, OPEN_FMODE(flags), fops);
+ if (!file)
+ goto err_dput;
+ file->f_mapping = anon_inode_inode->i_mapping;
+
+ file->f_pos = 0;
+ file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
+ file->f_version = 0;
+ file->private_data = priv;
+
+ return file;
+
+err_dput:
+ path_put(&path);
+err_module:
+ module_put(fops->owner);
+ return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(anon_inode_getfile);
+
+/**
+ * anon_inode_getfd - creates a new file instance by hooking it up to an
+ * anonymous inode, and a dentry that describe the "class"
+ * of the file
+ *
+ * @name: [in] name of the "class" of the new file
+ * @fops: [in] file operations for the new file
+ * @priv: [in] private data for the new file (will be file's private_data)
+ * @flags: [in] flags
+ *
+ * Creates a new file by hooking it on a single inode. This is useful for files
+ * that do not need to have a full-fledged inode in order to operate correctly.
+ * All the files created with anon_inode_getfd() will share a single inode,
+ * hence saving memory and avoiding code duplication for the file/inode/dentry
+ * setup. Returns new descriptor or an error code.
+ */
+int anon_inode_getfd(const char *name, const struct file_operations *fops,
+ void *priv, int flags)
+{
+ int error, fd;
+ struct file *file;
+
+ error = get_unused_fd_flags(flags);
+ if (error < 0)
+ return error;
+ fd = error;
+
+ file = anon_inode_getfile(name, fops, priv, flags);
+ if (IS_ERR(file)) {
+ error = PTR_ERR(file);
+ goto err_put_unused_fd;
+ }
+ fd_install(fd, file);
+
+ return fd;
+
+err_put_unused_fd:
+ put_unused_fd(fd);
+ return error;
+}
+EXPORT_SYMBOL_GPL(anon_inode_getfd);
+
+static int __init anon_inode_init(void)
+{
+ int error;
+
+ error = register_filesystem(&anon_inode_fs_type);
+ if (error)
+ goto err_exit;
+ anon_inode_mnt = kern_mount(&anon_inode_fs_type);
+ if (IS_ERR(anon_inode_mnt)) {
+ error = PTR_ERR(anon_inode_mnt);
+ goto err_unregister_filesystem;
+ }
+ return 0;
+
+err_unregister_filesystem:
+ unregister_filesystem(&anon_inode_fs_type);
+err_exit:
+ panic(KERN_ERR "anon_inode_init() failed (%d)\n", error);
+}
+
+fs_initcall(anon_inode_init);
+