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author | Miklos Szeredi <miklos@szeredi.hu> | 2005-09-09 13:10:27 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-09 14:03:44 -0700 |
commit | 334f485df85ac7736ebe14940bf0a059c5f26d7d (patch) | |
tree | 754e5528289048a7104f4c1b431cebc1df16e2ce /fs/fuse/fuse_i.h | |
parent | d8a5ba45457e4a22aa39c939121efd7bb6c76672 (diff) | |
download | blackbird-op-linux-334f485df85ac7736ebe14940bf0a059c5f26d7d.tar.gz blackbird-op-linux-334f485df85ac7736ebe14940bf0a059c5f26d7d.zip |
[PATCH] FUSE - device functions
This adds the FUSE device handling functions.
This contains the following files:
o dev.c
- fuse device operations (read, write, release, poll)
- registers misc device
- support for sending requests to userspace
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/fuse/fuse_i.h')
-rw-r--r-- | fs/fuse/fuse_i.h | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index eed6e89ce01f..50ad6a0c39bf 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -15,6 +15,12 @@ #include <linux/backing-dev.h> #include <asm/semaphore.h> +/** Max number of pages that can be used in a single read request */ +#define FUSE_MAX_PAGES_PER_REQ 32 + +/** If more requests are outstanding, then the operation will block */ +#define FUSE_MAX_OUTSTANDING 10 + /** FUSE inode */ struct fuse_inode { /** Inode data */ @@ -28,6 +34,123 @@ struct fuse_inode { unsigned long i_time; }; +/** 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; + + /** 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; + + /** Number or arguments */ + unsigned numargs; + + /** Array of arguments */ + struct fuse_arg args[3]; +}; + +struct fuse_req; +struct fuse_conn; + +/** + * A request to the client + */ +struct fuse_req { + /** This can be on either unused_list, pending or processing + lists in fuse_conn */ + struct list_head list; + + /** refcount */ + atomic_t count; + + /** True if the request has reply */ + unsigned isreply:1; + + /** The request is preallocated */ + unsigned preallocated:1; + + /** The request was interrupted */ + unsigned interrupted:1; + + /** Request is sent in the background */ + unsigned background:1; + + /** Data is being copied to/from the request */ + unsigned locked:1; + + /** Request has been sent to userspace */ + unsigned sent:1; + + /** The request is finished */ + unsigned finished:1; + + /** 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 fuse_init_in_out init_in_out; + } 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; + + /** Inode used in the request */ + struct inode *inode; + + /** Second inode used in the request (or NULL) */ + struct inode *inode2; + + /** File used in the request (or NULL) */ + struct file *file; +}; + /** * A Fuse connection. * @@ -39,9 +162,37 @@ struct fuse_conn { /** The superblock of the mounted filesystem */ struct super_block *sb; + /** The opened client device */ + struct file *file; + /** The user id for this mount */ uid_t user_id; + /** 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; + + /** Controls the maximum number of outstanding requests */ + struct semaphore outstanding_sem; + + /** This counts the number of outstanding requests if + outstanding_sem would go negative */ + unsigned outstanding_debt; + + /** The list of unused requests */ + struct list_head unused_list; + + /** The next unique request id */ + u64 reqctr; + + /** Connection failed (version mismatch) */ + unsigned conn_error : 1; + /** Backing dev info */ struct backing_dev_info bdi; }; @@ -71,13 +222,20 @@ static inline u64 get_node_id(struct inode *inode) return get_fuse_inode(inode)->nodeid; } +/** Device operations */ +extern struct file_operations fuse_dev_operations; + /** * This is the single global spinlock which protects FUSE's structures * * The following data is protected by this lock: * + * - the private_data field of the device file * - the s_fs_info field of the super block + * - unused_list, pending, processing lists in fuse_conn + * - the unique request ID counter reqctr in fuse_conn * - the sb (super_block) field in fuse_conn + * - the file (device file) field in fuse_conn */ extern spinlock_t fuse_lock; @@ -87,3 +245,68 @@ extern spinlock_t fuse_lock; */ void fuse_release_conn(struct fuse_conn *fc); +/** + * Initialize the client device + */ +int fuse_dev_init(void); + +/** + * Cleanup the client device + */ +void fuse_dev_cleanup(void); + +/** + * Allocate a request + */ +struct fuse_req *fuse_request_alloc(void); + +/** + * Free a request + */ +void fuse_request_free(struct fuse_req *req); + +/** + * Reinitialize a request, the preallocated flag is left unmodified + */ +void fuse_reset_request(struct fuse_req *req); + +/** + * Reserve a preallocated request + */ +struct fuse_req *fuse_get_request(struct fuse_conn *fc); + +/** + * Reserve a preallocated request, only interruptible by SIGKILL + */ +struct fuse_req *fuse_get_request_nonint(struct fuse_conn *fc); + +/** + * Decrement reference count of a request. If count goes to zero put + * on unused list (preallocated) or free reqest (not preallocated). + */ +void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req); + +/** + * Send a request (synchronous, interruptible) + */ +void request_send(struct fuse_conn *fc, struct fuse_req *req); + +/** + * Send a request (synchronous, non-interruptible except by SIGKILL) + */ +void request_send_nonint(struct fuse_conn *fc, struct fuse_req *req); + +/** + * Send a request with no reply + */ +void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); + +/** + * Send a request in the background + */ +void request_send_background(struct fuse_conn *fc, struct fuse_req *req); + +/** + * Send the INIT message + */ +void fuse_send_init(struct fuse_conn *fc); |