 a695f16729
			
		
	
	
	a695f16729
	
	
	
		
			
			If user space opens a unit record device node then vmur is leaving the kernel with lock open_mutex still held to prevent other processes from opening the device simultaneously. This causes lockdep to complain about a lock held when returning to user space. Now the mutex is replaced by a wait queue to serialize device open. Signed-off-by: Frank Munzert <munzert@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
		
			
				
	
	
		
			110 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Linux driver for System z and s390 unit record devices
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|  * (z/VM virtual punch, reader, printer)
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|  *
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|  * Copyright IBM Corp. 2001, 2007
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|  * Authors: Malcolm Beattie <beattiem@uk.ibm.com>
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|  *	    Michael Holzheu <holzheu@de.ibm.com>
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|  *	    Frank Munzert <munzert@de.ibm.com>
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|  */
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| 
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| #ifndef _VMUR_H_
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| #define _VMUR_H_
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| 
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| #define DEV_CLASS_UR_I 0x20 /* diag210 unit record input device class */
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| #define DEV_CLASS_UR_O 0x10 /* diag210 unit record output device class */
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| /*
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|  * we only support z/VM's default unit record devices:
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|  * both in SPOOL directory control statement and in CP DEFINE statement
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|  *	RDR defaults to 2540 reader
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|  *	PUN defaults to 2540 punch
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|  *	PRT defaults to 1403 printer
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|  */
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| #define READER_PUNCH_DEVTYPE	0x2540
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| #define PRINTER_DEVTYPE		0x1403
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| 
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| /* z/VM spool file control block SFBLOK */
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| struct file_control_block {
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| 	char reserved_1[8];
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| 	char user_owner[8];
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| 	char user_orig[8];
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| 	__s32 data_recs;
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| 	__s16 rec_len;
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| 	__s16 file_num;
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| 	__u8  file_stat;
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| 	__u8  dev_type;
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| 	char  reserved_2[6];
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| 	char  file_name[12];
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| 	char  file_type[12];
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| 	char  create_date[8];
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| 	char  create_time[8];
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| 	char  reserved_3[6];
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| 	__u8  file_class;
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| 	__u8  sfb_lok;
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| 	__u64 distr_code;
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| 	__u32 reserved_4;
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| 	__u8  current_starting_copy_number;
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| 	__u8  sfblock_cntrl_flags;
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| 	__u8  reserved_5;
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| 	__u8  more_status_flags;
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| 	char  rest[200];
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| } __attribute__ ((packed));
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| 
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| #define FLG_SYSTEM_HOLD	0x04
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| #define FLG_CP_DUMP	0x10
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| #define FLG_USER_HOLD	0x20
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| #define FLG_IN_USE	0x80
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| 
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| /*
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|  * A struct urdev is created for each ur device that is made available
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|  * via the ccw_device driver model.
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|  */
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| struct urdev {
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| 	struct ccw_device *cdev;	/* Backpointer to ccw device */
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| 	struct mutex io_mutex;		/* Serialises device IO */
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| 	struct completion *io_done;	/* do_ur_io waits; irq completes */
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| 	struct device *device;
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| 	struct cdev *char_device;
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| 	struct ccw_dev_id dev_id;	/* device id */
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| 	size_t reclen;			/* Record length for *write* CCWs */
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| 	int class;			/* VM device class */
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| 	int io_request_rc;		/* return code from I/O request */
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| 	atomic_t ref_count;		/* reference counter */
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| 	wait_queue_head_t wait;		/* wait queue to serialize open */
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| 	int open_flag;			/* "urdev is open" flag */
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| 	spinlock_t open_lock;		/* serialize critical sections */
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| };
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| 
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| /*
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|  * A struct urfile is allocated at open() time for each device and
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|  * freed on release().
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|  */
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| struct urfile {
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| 	struct urdev *urd;
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| 	unsigned int flags;
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| 	size_t dev_reclen;
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| 	__u16 file_reclen;
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| };
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| 
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| /*
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|  * Device major/minor definitions.
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|  */
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| 
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| #define UR_MAJOR 0	/* get dynamic major */
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| /*
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|  * We map minor numbers directly to device numbers (0-FFFF) for simplicity.
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|  * This avoids having to allocate (and manage) slot numbers.
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|  */
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| #define NUM_MINORS 65536
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| 
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| /* Limiting each I/O to 511 records limits chan prog to 4KB (511 r/w + 1 NOP) */
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| #define MAX_RECS_PER_IO		511
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| #define WRITE_CCW_CMD		0x01
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| 
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| #define TRACE(x...) debug_sprintf_event(vmur_dbf, 1, x)
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| #define CCWDEV_CU_DI(cutype, di) \
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| 		CCW_DEVICE(cutype, 0x00), .driver_info = (di)
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| 
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| #define FILE_RECLEN_OFFSET	4064 /* reclen offset in spool data block */
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| 
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| #endif /* _VMUR_H_ */
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