1 files changed, 784 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
new file mode 100644
index 00000000..d1819269
--- /dev/null
+++ b/fs/fuse/fuse_i.h
@@ -0,0 +1,784 @@
+/*
+  FUSE: Filesystem in Userspace
+  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
+
+  This program can be distributed under the terms of the GNU GPL.
+  See the file COPYING.
+*/
+
+#ifndef _FS_FUSE_I_H
+#define _FS_FUSE_I_H
+
+#include <linux/fuse.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/wait.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/backing-dev.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/rbtree.h>
+#include <linux/poll.h>
+#include <linux/workqueue.h>
+
+/** Max number of pages that can be used in a single read request */
+#define FUSE_MAX_PAGES_PER_REQ 32
+
+/** Bias for fi->writectr, meaning new writepages must not be sent */
+#define FUSE_NOWRITE INT_MIN
+
+/** It could be as large as PATH_MAX, but would that have any uses? */
+#define FUSE_NAME_MAX 1024
+
+/** Number of dentries for each connection in the control filesystem */
+#define FUSE_CTL_NUM_DENTRIES 5
+
+/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
+    module will check permissions based on the file mode.  Otherwise no
+    permission checking is done in the kernel */
+#define FUSE_DEFAULT_PERMISSIONS (1 << 0)
+
+/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
+    doing the mount will be allowed to access the filesystem */
+#define FUSE_ALLOW_OTHER         (1 << 1)
+
+/** List of active connections */
+extern struct list_head fuse_conn_list;
+
+/** Global mutex protecting fuse_conn_list and the control filesystem */
+extern struct mutex fuse_mutex;
+
+/** Module parameters */
+extern unsigned max_user_bgreq;
+extern unsigned max_user_congthresh;
+
+/* One forget request */
+struct fuse_forget_link {
+	struct fuse_forget_one forget_one;
+	struct fuse_forget_link *next;
+};
+
+/** FUSE inode */
+struct fuse_inode {
+	/** Inode data */
+	struct inode inode;
+
+	/** Unique ID, which identifies the inode between userspace
+	 * and kernel */
+	u64 nodeid;
+
+	/** Number of lookups on this inode */
+	u64 nlookup;
+
+	/** The request used for sending the FORGET message */
+	struct fuse_forget_link *forget;
+
+	/** Time in jiffies until the file attributes are valid */
+	u64 i_time;
+
+	/** The sticky bit in inode->i_mode may have been removed, so
+	    preserve the original mode */
+	umode_t orig_i_mode;
+
+	/** 64 bit inode number */
+	u64 orig_ino;
+
+	/** Version of last attribute change */
+	u64 attr_version;
+
+	/** Files usable in writepage.  Protected by fc->lock */
+	struct list_head write_files;
+
+	/** Writepages pending on truncate or fsync */
+	struct list_head queued_writes;
+
+	/** Number of sent writes, a negative bias (FUSE_NOWRITE)
+	 * means more writes are blocked */
+	int writectr;
+
+	/** Waitq for writepage completion */
+	wait_queue_head_t page_waitq;
+
+	/** List of writepage requestst (pending or sent) */
+	struct list_head writepages;
+};
+
+struct fuse_conn;
+
+/** FUSE specific file data */
+struct fuse_file {
+	/** Fuse connection for this file */
+	struct fuse_conn *fc;
+
+	/** Request reserved for flush and release */
+	struct fuse_req *reserved_req;
+
+	/** Kernel file handle guaranteed to be unique */
+	u64 kh;
+
+	/** File handle used by userspace */
+	u64 fh;
+
+	/** Node id of this file */
+	u64 nodeid;
+
+	/** Refcount */
+	atomic_t count;
+
+	/** FOPEN_* flags returned by open */
+	u32 open_flags;
+
+	/** Entry on inode's write_files list */
+	struct list_head write_entry;
+
+	/** RB node to be linked on fuse_conn->polled_files */
+	struct rb_node polled_node;
+
+	/** Wait queue head for poll */
+	wait_queue_head_t poll_wait;
+
+	/** Has flock been performed on this file? */
+	bool flock:1;
+};
+
+/** One input argument of a request */
+struct fuse_in_arg {
+	unsigned size;
+	const void *value;
+};
+
+/** The request input */
+struct fuse_in {
+	/** The request header */
+	struct fuse_in_header h;
+
+	/** True if the data for the last argument is in req->pages */
+	unsigned argpages:1;
+
+	/** Number of arguments */
+	unsigned numargs;
+
+	/** Array of arguments */
+	struct fuse_in_arg args[3];
+};
+
+/** One output argument of a request */
+struct fuse_arg {
+	unsigned size;
+	void *value;
+};
+
+/** The request output */
+struct fuse_out {
+	/** Header returned from userspace */
+	struct fuse_out_header h;
+
+	/*
+	 * The following bitfields are not changed during the request
+	 * processing
+	 */
+
+	/** Last argument is variable length (can be shorter than
+	    arg->size) */
+	unsigned argvar:1;
+
+	/** Last argument is a list of pages to copy data to */
+	unsigned argpages:1;
+
+	/** Zero partially or not copied pages */
+	unsigned page_zeroing:1;
+
+	/** Pages may be replaced with new ones */
+	unsigned page_replace:1;
+
+	/** Number or arguments */
+	unsigned numargs;
+
+	/** Array of arguments */
+	struct fuse_arg args[3];
+};
+
+/** The request state */
+enum fuse_req_state {
+	FUSE_REQ_INIT = 0,
+	FUSE_REQ_PENDING,
+	FUSE_REQ_READING,
+	FUSE_REQ_SENT,
+	FUSE_REQ_WRITING,
+	FUSE_REQ_FINISHED
+};
+
+/**
+ * A request to the client
+ */
+struct fuse_req {
+	/** This can be on either pending processing or io lists in
+	    fuse_conn */
+	struct list_head list;
+
+	/** Entry on the interrupts list  */
+	struct list_head intr_entry;
+
+	/** refcount */
+	atomic_t count;
+
+	/** Unique ID for the interrupt request */
+	u64 intr_unique;
+
+	/*
+	 * The following bitfields are either set once before the
+	 * request is queued or setting/clearing them is protected by
+	 * fuse_conn->lock
+	 */
+
+	/** True if the request has reply */
+	unsigned isreply:1;
+
+	/** Force sending of the request even if interrupted */
+	unsigned force:1;
+
+	/** The request was aborted */
+	unsigned aborted:1;
+
+	/** Request is sent in the background */
+	unsigned background:1;
+
+	/** The request has been interrupted */
+	unsigned interrupted:1;
+
+	/** Data is being copied to/from the request */
+	unsigned locked:1;
+
+	/** Request is counted as "waiting" */
+	unsigned waiting:1;
+
+	/** State of the request */
+	enum fuse_req_state state;
+
+	/** The request input */
+	struct fuse_in in;
+
+	/** The request output */
+	struct fuse_out out;
+
+	/** Used to wake up the task waiting for completion of request*/
+	wait_queue_head_t waitq;
+
+	/** Data for asynchronous requests */
+	union {
+		struct {
+			union {
+				struct fuse_release_in in;
+				struct work_struct work;
+			};
+			struct path path;
+		} release;
+		struct fuse_init_in init_in;
+		struct fuse_init_out init_out;
+		struct cuse_init_in cuse_init_in;
+		struct {
+			struct fuse_read_in in;
+			u64 attr_ver;
+		} read;
+		struct {
+			struct fuse_write_in in;
+			struct fuse_write_out out;
+		} write;
+		struct fuse_notify_retrieve_in retrieve_in;
+		struct fuse_lk_in lk_in;
+	} misc;
+
+	/** page vector */
+	struct page *pages[FUSE_MAX_PAGES_PER_REQ];
+
+	/** number of pages in vector */
+	unsigned num_pages;
+
+	/** offset of data on first page */
+	unsigned page_offset;
+
+	/** File used in the request (or NULL) */
+	struct fuse_file *ff;
+
+	/** Inode used in the request or NULL */
+	struct inode *inode;
+
+	/** Link on fi->writepages */
+	struct list_head writepages_entry;
+
+	/** Request completion callback */
+	void (*end)(struct fuse_conn *, struct fuse_req *);
+
+	/** Request is stolen from fuse_file->reserved_req */
+	struct file *stolen_file;
+};
+
+/**
+ * A Fuse connection.
+ *
+ * This structure is created, when the filesystem is mounted, and is
+ * destroyed, when the client device is closed and the filesystem is
+ * unmounted.
+ */
+struct fuse_conn {
+	/** Lock protecting accessess to  members of this structure */
+	spinlock_t lock;
+
+	/** Mutex protecting against directory alias creation */
+	struct mutex inst_mutex;
+
+	/** Refcount */
+	atomic_t count;
+
+	/** The user id for this mount */
+	uid_t user_id;
+
+	/** The group id for this mount */
+	gid_t group_id;
+
+	/** The fuse mount flags for this mount */
+	unsigned flags;
+
+	/** Maximum read size */
+	unsigned max_read;
+
+	/** Maximum write size */
+	unsigned max_write;
+
+	/** Readers of the connection are waiting on this */
+	wait_queue_head_t waitq;
+
+	/** The list of pending requests */
+	struct list_head pending;
+
+	/** The list of requests being processed */
+	struct list_head processing;
+
+	/** The list of requests under I/O */
+	struct list_head io;
+
+	/** The next unique kernel file handle */
+	u64 khctr;
+
+	/** rbtree of fuse_files waiting for poll events indexed by ph */
+	struct rb_root polled_files;
+
+	/** Maximum number of outstanding background requests */
+	unsigned max_background;
+
+	/** Number of background requests at which congestion starts */
+	unsigned congestion_threshold;
+
+	/** Number of requests currently in the background */
+	unsigned num_background;
+
+	/** Number of background requests currently queued for userspace */
+	unsigned active_background;
+
+	/** The list of background requests set aside for later queuing */
+	struct list_head bg_queue;
+
+	/** Pending interrupts */
+	struct list_head interrupts;
+
+	/** Queue of pending forgets */
+	struct fuse_forget_link forget_list_head;
+	struct fuse_forget_link *forget_list_tail;
+
+	/** Batching of FORGET requests (positive indicates FORGET batch) */
+	int forget_batch;
+
+	/** Flag indicating if connection is blocked.  This will be
+	    the case before the INIT reply is received, and if there
+	    are too many outstading backgrounds requests */
+	int blocked;
+
+	/** waitq for blocked connection */
+	wait_queue_head_t blocked_waitq;
+
+	/** waitq for reserved requests */
+	wait_queue_head_t reserved_req_waitq;
+
+	/** The next unique request id */
+	u64 reqctr;
+
+	/** Connection established, cleared on umount, connection
+	    abort and device release */
+	unsigned connected;
+
+	/** Connection failed (version mismatch).  Cannot race with
+	    setting other bitfields since it is only set once in INIT
+	    reply, before any other request, and never cleared */
+	unsigned conn_error:1;
+
+	/** Connection successful.  Only set in INIT */
+	unsigned conn_init:1;
+
+	/** Do readpages asynchronously?  Only set in INIT */
+	unsigned async_read:1;
+
+	/** Do not send separate SETATTR request before open(O_TRUNC)  */
+	unsigned atomic_o_trunc:1;
+
+	/** Filesystem supports NFS exporting.  Only set in INIT */
+	unsigned export_support:1;
+
+	/** Set if bdi is valid */
+	unsigned bdi_initialized:1;
+
+	/*
+	 * The following bitfields are only for optimization purposes
+	 * and hence races in setting them will not cause malfunction
+	 */
+
+	/** Is fsync not implemented by fs? */
+	unsigned no_fsync:1;
+
+	/** Is fsyncdir not implemented by fs? */
+	unsigned no_fsyncdir:1;
+
+	/** Is flush not implemented by fs? */
+	unsigned no_flush:1;
+
+	/** Is setxattr not implemented by fs? */
+	unsigned no_setxattr:1;
+
+	/** Is getxattr not implemented by fs? */
+	unsigned no_getxattr:1;
+
+	/** Is listxattr not implemented by fs? */
+	unsigned no_listxattr:1;
+
+	/** Is removexattr not implemented by fs? */
+	unsigned no_removexattr:1;
+
+	/** Are posix file locking primitives not implemented by fs? */
+	unsigned no_lock:1;
+
+	/** Is access not implemented by fs? */
+	unsigned no_access:1;
+
+	/** Is create not implemented by fs? */
+	unsigned no_create:1;
+
+	/** Is interrupt not implemented by fs? */
+	unsigned no_interrupt:1;
+
+	/** Is bmap not implemented by fs? */
+	unsigned no_bmap:1;
+
+	/** Is poll not implemented by fs? */
+	unsigned no_poll:1;
+
+	/** Do multi-page cached writes */
+	unsigned big_writes:1;
+
+	/** Don't apply umask to creation modes */
+	unsigned dont_mask:1;
+
+	/** Are BSD file locking primitives not implemented by fs? */
+	unsigned no_flock:1;
+
+	/** The number of requests waiting for completion */
+	atomic_t num_waiting;
+
+	/** Negotiated minor version */
+	unsigned minor;
+
+	/** Backing dev info */
+	struct backing_dev_info bdi;
+
+	/** Entry on the fuse_conn_list */
+	struct list_head entry;
+
+	/** Device ID from super block */
+	dev_t dev;
+
+	/** Dentries in the control filesystem */
+	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
+
+	/** number of dentries used in the above array */
+	int ctl_ndents;
+
+	/** O_ASYNC requests */
+	struct fasync_struct *fasync;
+
+	/** Key for lock owner ID scrambling */
+	u32 scramble_key[4];
+
+	/** Reserved request for the DESTROY message */
+	struct fuse_req *destroy_req;
+
+	/** Version counter for attribute changes */
+	u64 attr_version;
+
+	/** Called on final put */
+	void (*release)(struct fuse_conn *);
+
+	/** Super block for this connection. */
+	struct super_block *sb;
+
+	/** Read/write semaphore to hold when accessing sb. */
+	struct rw_semaphore killsb;
+};
+
+static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
+{
+	return get_fuse_conn_super(inode->i_sb);
+}
+
+static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
+{
+	return container_of(inode, struct fuse_inode, inode);
+}
+
+static inline u64 get_node_id(struct inode *inode)
+{
+	return get_fuse_inode(inode)->nodeid;
+}
+
+/** Device operations */
+extern const struct file_operations fuse_dev_operations;
+
+extern const struct dentry_operations fuse_dentry_operations;
+
+/**
+ * Inode to nodeid comparison.
+ */
+int fuse_inode_eq(struct inode *inode, void *_nodeidp);
+
+/**
+ * Get a filled in inode
+ */
+struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
+			int generation, struct fuse_attr *attr,
+			u64 attr_valid, u64 attr_version);
+
+int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
+		     struct fuse_entry_out *outarg, struct inode **inode);
+
+/**
+ * Send FORGET command
+ */
+void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
+		       u64 nodeid, u64 nlookup);
+
+struct fuse_forget_link *fuse_alloc_forget(void);
+
+/**
+ * Initialize READ or READDIR request
+ */
+void fuse_read_fill(struct fuse_req *req, struct file *file,
+		    loff_t pos, size_t count, int opcode);
+
+/**
+ * Send OPEN or OPENDIR request
+ */
+int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
+
+struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
+struct fuse_file *fuse_file_get(struct fuse_file *ff);
+void fuse_file_free(struct fuse_file *ff);
+void fuse_finish_open(struct inode *inode, struct file *file);
+
+void fuse_sync_release(struct fuse_file *ff, int flags);
+
+/**
+ * Send RELEASE or RELEASEDIR request
+ */
+void fuse_release_common(struct file *file, int opcode);
+
+/**
+ * Send FSYNC or FSYNCDIR request
+ */
+int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
+		      int datasync, int isdir);
+
+/**
+ * Notify poll wakeup
+ */
+int fuse_notify_poll_wakeup(struct fuse_conn *fc,
+			    struct fuse_notify_poll_wakeup_out *outarg);
+
+/**
+ * Initialize file operations on a regular file
+ */
+void fuse_init_file_inode(struct inode *inode);
+
+/**
+ * Initialize inode operations on regular files and special files
+ */
+void fuse_init_common(struct inode *inode);
+
+/**
+ * Initialize inode and file operations on a directory
+ */
+void fuse_init_dir(struct inode *inode);
+
+/**
+ * Initialize inode operations on a symlink
+ */
+void fuse_init_symlink(struct inode *inode);
+
+/**
+ * Change attributes of an inode
+ */
+void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			    u64 attr_valid, u64 attr_version);
+
+void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
+				   u64 attr_valid);
+
+/**
+ * Initialize the client device
+ */
+int fuse_dev_init(void);
+
+/**
+ * Cleanup the client device
+ */
+void fuse_dev_cleanup(void);
+
+int fuse_ctl_init(void);
+void fuse_ctl_cleanup(void);
+
+/**
+ * Allocate a request
+ */
+struct fuse_req *fuse_request_alloc(void);
+
+struct fuse_req *fuse_request_alloc_nofs(void);
+
+/**
+ * Free a request
+ */
+void fuse_request_free(struct fuse_req *req);
+
+/**
+ * Get a request, may fail with -ENOMEM
+ */
+struct fuse_req *fuse_get_req(struct fuse_conn *fc);
+
+/**
+ * Gets a requests for a file operation, always succeeds
+ */
+struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
+
+/**
+ * Decrement reference count of a request.  If count goes to zero free
+ * the request.
+ */
+void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Send a request (synchronous)
+ */
+void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
+
+/**
+ * Send a request in the background
+ */
+void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
+
+void fuse_request_send_background_locked(struct fuse_conn *fc,
+					 struct fuse_req *req);
+
+/* Abort all requests */
+void fuse_abort_conn(struct fuse_conn *fc);
+
+/**
+ * Invalidate inode attributes
+ */
+void fuse_invalidate_attr(struct inode *inode);
+
+void fuse_invalidate_entry_cache(struct dentry *entry);
+
+/**
+ * Acquire reference to fuse_conn
+ */
+struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
+
+void fuse_conn_kill(struct fuse_conn *fc);
+
+/**
+ * Initialize fuse_conn
+ */
+void fuse_conn_init(struct fuse_conn *fc);
+
+/**
+ * Release reference to fuse_conn
+ */
+void fuse_conn_put(struct fuse_conn *fc);
+
+/**
+ * Add connection to control filesystem
+ */
+int fuse_ctl_add_conn(struct fuse_conn *fc);
+
+/**
+ * Remove connection from control filesystem
+ */
+void fuse_ctl_remove_conn(struct fuse_conn *fc);
+
+/**
+ * Is file type valid?
+ */
+int fuse_valid_type(int m);
+
+/**
+ * Is task allowed to perform filesystem operation?
+ */
+int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
+
+u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
+
+int fuse_update_attributes(struct inode *inode, struct kstat *stat,
+			   struct file *file, bool *refreshed);
+
+void fuse_flush_writepages(struct inode *inode);
+
+void fuse_set_nowrite(struct inode *inode);
+void fuse_release_nowrite(struct inode *inode);
+
+u64 fuse_get_attr_version(struct fuse_conn *fc);
+
+/**
+ * File-system tells the kernel to invalidate cache for the given node id.
+ */
+int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
+			     loff_t offset, loff_t len);
+
+/**
+ * File-system tells the kernel to invalidate parent attributes and
+ * the dentry matching parent/name.
+ *
+ * If the child_nodeid is non-zero and:
+ *    - matches the inode number for the dentry matching parent/name,
+ *    - is not a mount point
+ *    - is a file or oan empty directory
+ * then the dentry is unhashed (d_delete()).
+ */
+int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
+			     u64 child_nodeid, struct qstr *name);
+
+int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
+		 bool isdir);
+ssize_t fuse_direct_io(struct file *file, const char __user *buf,
+		       size_t count, loff_t *ppos, int write);
+long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
+		   unsigned int flags);
+long fuse_ioctl_common(struct file *file, unsigned int cmd,
+		       unsigned long arg, unsigned int flags);
+unsigned fuse_file_poll(struct file *file, poll_table *wait);
+int fuse_dev_release(struct inode *inode, struct file *file);
+
+void fuse_write_update_size(struct inode *inode, loff_t pos);
+
+#endif /* _FS_FUSE_I_H */