Miklos Szeredi | d8a5ba4 | 2005-09-09 13:10:26 -0700 | [diff] [blame^] | 1 | /* |
| 2 | FUSE: Filesystem in Userspace |
| 3 | Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu> |
| 4 | |
| 5 | This program can be distributed under the terms of the GNU GPL. |
| 6 | See the file COPYING. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/fuse.h> |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/wait.h> |
| 12 | #include <linux/list.h> |
| 13 | #include <linux/spinlock.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/backing-dev.h> |
| 16 | #include <asm/semaphore.h> |
| 17 | |
| 18 | /** FUSE inode */ |
| 19 | struct fuse_inode { |
| 20 | /** Inode data */ |
| 21 | struct inode inode; |
| 22 | |
| 23 | /** Unique ID, which identifies the inode between userspace |
| 24 | * and kernel */ |
| 25 | u64 nodeid; |
| 26 | |
| 27 | /** Time in jiffies until the file attributes are valid */ |
| 28 | unsigned long i_time; |
| 29 | }; |
| 30 | |
| 31 | /** |
| 32 | * A Fuse connection. |
| 33 | * |
| 34 | * This structure is created, when the filesystem is mounted, and is |
| 35 | * destroyed, when the client device is closed and the filesystem is |
| 36 | * unmounted. |
| 37 | */ |
| 38 | struct fuse_conn { |
| 39 | /** The superblock of the mounted filesystem */ |
| 40 | struct super_block *sb; |
| 41 | |
| 42 | /** The user id for this mount */ |
| 43 | uid_t user_id; |
| 44 | |
| 45 | /** Backing dev info */ |
| 46 | struct backing_dev_info bdi; |
| 47 | }; |
| 48 | |
| 49 | static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb) |
| 50 | { |
| 51 | return (struct fuse_conn **) &sb->s_fs_info; |
| 52 | } |
| 53 | |
| 54 | static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) |
| 55 | { |
| 56 | return *get_fuse_conn_super_p(sb); |
| 57 | } |
| 58 | |
| 59 | static inline struct fuse_conn *get_fuse_conn(struct inode *inode) |
| 60 | { |
| 61 | return get_fuse_conn_super(inode->i_sb); |
| 62 | } |
| 63 | |
| 64 | static inline struct fuse_inode *get_fuse_inode(struct inode *inode) |
| 65 | { |
| 66 | return container_of(inode, struct fuse_inode, inode); |
| 67 | } |
| 68 | |
| 69 | static inline u64 get_node_id(struct inode *inode) |
| 70 | { |
| 71 | return get_fuse_inode(inode)->nodeid; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * This is the single global spinlock which protects FUSE's structures |
| 76 | * |
| 77 | * The following data is protected by this lock: |
| 78 | * |
| 79 | * - the s_fs_info field of the super block |
| 80 | * - the sb (super_block) field in fuse_conn |
| 81 | */ |
| 82 | extern spinlock_t fuse_lock; |
| 83 | |
| 84 | /** |
| 85 | * Check if the connection can be released, and if yes, then free the |
| 86 | * connection structure |
| 87 | */ |
| 88 | void fuse_release_conn(struct fuse_conn *fc); |
| 89 | |