Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
new file mode 100644
index 0000000..e5c14e2
--- /dev/null
+++ b/include/linux/fs_context.h
@@ -0,0 +1,228 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Filesystem superblock creation and reconfiguration context.
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _LINUX_FS_CONTEXT_H
+#define _LINUX_FS_CONTEXT_H
+
+#include <linux/kernel.h>
+#include <linux/refcount.h>
+#include <linux/errno.h>
+#include <linux/security.h>
+#include <linux/mutex.h>
+
+struct cred;
+struct dentry;
+struct file_operations;
+struct file_system_type;
+struct mnt_namespace;
+struct net;
+struct pid_namespace;
+struct super_block;
+struct user_namespace;
+struct vfsmount;
+struct path;
+
+enum fs_context_purpose {
+ FS_CONTEXT_FOR_MOUNT, /* New superblock for explicit mount */
+ FS_CONTEXT_FOR_SUBMOUNT, /* New superblock for automatic submount */
+ FS_CONTEXT_FOR_RECONFIGURE, /* Superblock reconfiguration (remount) */
+};
+
+/*
+ * Userspace usage phase for fsopen/fspick.
+ */
+enum fs_context_phase {
+ FS_CONTEXT_CREATE_PARAMS, /* Loading params for sb creation */
+ FS_CONTEXT_CREATING, /* A superblock is being created */
+ FS_CONTEXT_AWAITING_MOUNT, /* Superblock created, awaiting fsmount() */
+ FS_CONTEXT_AWAITING_RECONF, /* Awaiting initialisation for reconfiguration */
+ FS_CONTEXT_RECONF_PARAMS, /* Loading params for reconfiguration */
+ FS_CONTEXT_RECONFIGURING, /* Reconfiguring the superblock */
+ FS_CONTEXT_FAILED, /* Failed to correctly transition a context */
+};
+
+/*
+ * Type of parameter value.
+ */
+enum fs_value_type {
+ fs_value_is_undefined,
+ fs_value_is_flag, /* Value not given a value */
+ fs_value_is_string, /* Value is a string */
+ fs_value_is_blob, /* Value is a binary blob */
+ fs_value_is_filename, /* Value is a filename* + dirfd */
+ fs_value_is_filename_empty, /* Value is a filename* + dirfd + AT_EMPTY_PATH */
+ fs_value_is_file, /* Value is a file* */
+};
+
+/*
+ * Configuration parameter.
+ */
+struct fs_parameter {
+ const char *key; /* Parameter name */
+ enum fs_value_type type:8; /* The type of value here */
+ union {
+ char *string;
+ void *blob;
+ struct filename *name;
+ struct file *file;
+ };
+ size_t size;
+ int dirfd;
+};
+
+/*
+ * Filesystem context for holding the parameters used in the creation or
+ * reconfiguration of a superblock.
+ *
+ * Superblock creation fills in ->root whereas reconfiguration begins with this
+ * already set.
+ *
+ * See Documentation/filesystems/mount_api.txt
+ */
+struct fs_context {
+ const struct fs_context_operations *ops;
+ struct mutex uapi_mutex; /* Userspace access mutex */
+ struct file_system_type *fs_type;
+ void *fs_private; /* The filesystem's context */
+ void *sget_key;
+ struct dentry *root; /* The root and superblock */
+ struct user_namespace *user_ns; /* The user namespace for this mount */
+ struct net *net_ns; /* The network namespace for this mount */
+ const struct cred *cred; /* The mounter's credentials */
+ struct fc_log *log; /* Logging buffer */
+ const char *source; /* The source name (eg. dev path) */
+ void *security; /* Linux S&M options */
+ void *s_fs_info; /* Proposed s_fs_info */
+ unsigned int sb_flags; /* Proposed superblock flags (SB_*) */
+ unsigned int sb_flags_mask; /* Superblock flags that were changed */
+ unsigned int s_iflags; /* OR'd with sb->s_iflags */
+ unsigned int lsm_flags; /* Information flags from the fs to the LSM */
+ enum fs_context_purpose purpose:8;
+ enum fs_context_phase phase:8; /* The phase the context is in */
+ bool need_free:1; /* Need to call ops->free() */
+ bool global:1; /* Goes into &init_user_ns */
+};
+
+struct fs_context_operations {
+ void (*free)(struct fs_context *fc);
+ int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
+ int (*parse_param)(struct fs_context *fc, struct fs_parameter *param);
+ int (*parse_monolithic)(struct fs_context *fc, void *data);
+ int (*get_tree)(struct fs_context *fc);
+ int (*reconfigure)(struct fs_context *fc);
+};
+
+/*
+ * fs_context manipulation functions.
+ */
+extern struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
+ unsigned int sb_flags);
+extern struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
+ unsigned int sb_flags,
+ unsigned int sb_flags_mask);
+extern struct fs_context *fs_context_for_submount(struct file_system_type *fs_type,
+ struct dentry *reference);
+
+extern struct fs_context *vfs_dup_fs_context(struct fs_context *fc);
+extern int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param);
+extern int vfs_parse_fs_string(struct fs_context *fc, const char *key,
+ const char *value, size_t v_size);
+extern int generic_parse_monolithic(struct fs_context *fc, void *data);
+extern int vfs_get_tree(struct fs_context *fc);
+extern void put_fs_context(struct fs_context *fc);
+
+/*
+ * sget() wrappers to be called from the ->get_tree() op.
+ */
+enum vfs_get_super_keying {
+ vfs_get_single_super, /* Only one such superblock may exist */
+ vfs_get_single_reconf_super, /* As above, but reconfigure if it exists */
+ vfs_get_keyed_super, /* Superblocks with different s_fs_info keys may exist */
+ vfs_get_independent_super, /* Multiple independent superblocks may exist */
+};
+extern int vfs_get_super(struct fs_context *fc,
+ enum vfs_get_super_keying keying,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
+
+extern int get_tree_nodev(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
+extern int get_tree_single(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
+extern int get_tree_single_reconf(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
+extern int get_tree_keyed(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc),
+ void *key);
+
+extern int get_tree_bdev(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
+
+extern const struct file_operations fscontext_fops;
+
+/*
+ * Mount error, warning and informational message logging. This structure is
+ * shareable between a mount and a subordinate mount.
+ */
+struct fc_log {
+ refcount_t usage;
+ u8 head; /* Insertion index in buffer[] */
+ u8 tail; /* Removal index in buffer[] */
+ u8 need_free; /* Mask of kfree'able items in buffer[] */
+ struct module *owner; /* Owner module for strings that don't then need freeing */
+ char *buffer[8];
+};
+
+extern __attribute__((format(printf, 2, 3)))
+void logfc(struct fs_context *fc, const char *fmt, ...);
+
+/**
+ * infof - Store supplementary informational message
+ * @fc: The context in which to log the informational message
+ * @fmt: The format string
+ *
+ * Store the supplementary informational message for the process if the process
+ * has enabled the facility.
+ */
+#define infof(fc, fmt, ...) ({ logfc(fc, "i "fmt, ## __VA_ARGS__); })
+
+/**
+ * warnf - Store supplementary warning message
+ * @fc: The context in which to log the error message
+ * @fmt: The format string
+ *
+ * Store the supplementary warning message for the process if the process has
+ * enabled the facility.
+ */
+#define warnf(fc, fmt, ...) ({ logfc(fc, "w "fmt, ## __VA_ARGS__); })
+
+/**
+ * errorf - Store supplementary error message
+ * @fc: The context in which to log the error message
+ * @fmt: The format string
+ *
+ * Store the supplementary error message for the process if the process has
+ * enabled the facility.
+ */
+#define errorf(fc, fmt, ...) ({ logfc(fc, "e "fmt, ## __VA_ARGS__); })
+
+/**
+ * invalf - Store supplementary invalid argument error message
+ * @fc: The context in which to log the error message
+ * @fmt: The format string
+ *
+ * Store the supplementary error message for the process if the process has
+ * enabled the facility and return -EINVAL.
+ */
+#define invalf(fc, fmt, ...) ({ errorf(fc, fmt, ## __VA_ARGS__); -EINVAL; })
+
+#endif /* _LINUX_FS_CONTEXT_H */