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![Jens Axboe](/assets/img/avatar_default.png)
This reverts commit f40eb99897
.
There are apparently still users out there of this driver. While we'd
love to remove it to ease the maintenance burden, let's reinstate it
for now until better (userspace) solutions can be developed.
Link: https://lore.kernel.org/lkml/20230104190115.ceglfefco475ev6c@pali/
Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
197 lines
5.6 KiB
C
197 lines
5.6 KiB
C
/*
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* Copyright (C) 2000 Jens Axboe <axboe@suse.de>
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* Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
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*
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* May be copied or modified under the terms of the GNU General Public
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* License. See linux/COPYING for more information.
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*
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* Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
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* DVD-RW devices.
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*
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*/
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#ifndef __PKTCDVD_H
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#define __PKTCDVD_H
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#include <linux/blkdev.h>
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#include <linux/completion.h>
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#include <linux/cdrom.h>
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#include <linux/kobject.h>
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#include <linux/sysfs.h>
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#include <linux/mempool.h>
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#include <uapi/linux/pktcdvd.h>
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/* default bio write queue congestion marks */
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#define PKT_WRITE_CONGESTION_ON 10000
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#define PKT_WRITE_CONGESTION_OFF 9000
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struct packet_settings
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{
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__u32 size; /* packet size in (512 byte) sectors */
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__u8 fp; /* fixed packets */
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__u8 link_loss; /* the rest is specified
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* as per Mt Fuji */
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__u8 write_type;
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__u8 track_mode;
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__u8 block_mode;
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};
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/*
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* Very crude stats for now
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*/
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struct packet_stats
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{
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unsigned long pkt_started;
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unsigned long pkt_ended;
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unsigned long secs_w;
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unsigned long secs_rg;
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unsigned long secs_r;
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};
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struct packet_cdrw
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{
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struct list_head pkt_free_list;
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struct list_head pkt_active_list;
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spinlock_t active_list_lock; /* Serialize access to pkt_active_list */
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struct task_struct *thread;
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atomic_t pending_bios;
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};
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/*
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* Switch to high speed reading after reading this many kilobytes
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* with no interspersed writes.
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*/
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#define HI_SPEED_SWITCH 512
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struct packet_iosched
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{
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atomic_t attention; /* Set to non-zero when queue processing is needed */
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int writing; /* Non-zero when writing, zero when reading */
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spinlock_t lock; /* Protecting read/write queue manipulations */
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struct bio_list read_queue;
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struct bio_list write_queue;
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sector_t last_write; /* The sector where the last write ended */
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int successive_reads;
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};
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/*
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* 32 buffers of 2048 bytes
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*/
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#if (PAGE_SIZE % CD_FRAMESIZE) != 0
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#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
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#endif
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#define PACKET_MAX_SIZE 128
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#define FRAMES_PER_PAGE (PAGE_SIZE / CD_FRAMESIZE)
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#define PACKET_MAX_SECTORS (PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
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enum packet_data_state {
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PACKET_IDLE_STATE, /* Not used at the moment */
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PACKET_WAITING_STATE, /* Waiting for more bios to arrive, so */
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/* we don't have to do as much */
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/* data gathering */
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PACKET_READ_WAIT_STATE, /* Waiting for reads to fill in holes */
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PACKET_WRITE_WAIT_STATE, /* Waiting for the write to complete */
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PACKET_RECOVERY_STATE, /* Recover after read/write errors */
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PACKET_FINISHED_STATE, /* After write has finished */
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PACKET_NUM_STATES /* Number of possible states */
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};
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/*
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* Information needed for writing a single packet
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*/
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struct pktcdvd_device;
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struct packet_data
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{
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struct list_head list;
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spinlock_t lock; /* Lock protecting state transitions and */
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/* orig_bios list */
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struct bio_list orig_bios; /* Original bios passed to pkt_make_request */
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/* that will be handled by this packet */
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int write_size; /* Total size of all bios in the orig_bios */
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/* list, measured in number of frames */
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struct bio *w_bio; /* The bio we will send to the real CD */
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/* device once we have all data for the */
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/* packet we are going to write */
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sector_t sector; /* First sector in this packet */
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int frames; /* Number of frames in this packet */
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enum packet_data_state state; /* Current state */
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atomic_t run_sm; /* Incremented whenever the state */
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/* machine needs to be run */
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long sleep_time; /* Set this to non-zero to make the state */
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/* machine run after this many jiffies. */
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atomic_t io_wait; /* Number of pending IO operations */
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atomic_t io_errors; /* Number of read/write errors during IO */
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struct bio *r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
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struct page *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
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int cache_valid; /* If non-zero, the data for the zone defined */
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/* by the sector variable is completely cached */
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/* in the pages[] vector. */
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int id; /* ID number for debugging */
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struct pktcdvd_device *pd;
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};
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struct pkt_rb_node {
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struct rb_node rb_node;
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struct bio *bio;
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};
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struct packet_stacked_data
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{
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struct bio *bio; /* Original read request bio */
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struct pktcdvd_device *pd;
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};
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#define PSD_POOL_SIZE 64
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struct pktcdvd_device
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{
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struct block_device *bdev; /* dev attached */
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dev_t pkt_dev; /* our dev */
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char name[20];
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struct packet_settings settings;
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struct packet_stats stats;
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int refcnt; /* Open count */
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int write_speed; /* current write speed, kB/s */
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int read_speed; /* current read speed, kB/s */
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unsigned long offset; /* start offset */
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__u8 mode_offset; /* 0 / 8 */
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__u8 type;
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unsigned long flags;
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__u16 mmc3_profile;
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__u32 nwa; /* next writable address */
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__u32 lra; /* last recorded address */
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struct packet_cdrw cdrw;
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wait_queue_head_t wqueue;
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spinlock_t lock; /* Serialize access to bio_queue */
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struct rb_root bio_queue; /* Work queue of bios we need to handle */
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int bio_queue_size; /* Number of nodes in bio_queue */
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bool congested; /* Someone is waiting for bio_queue_size
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* to drop. */
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sector_t current_sector; /* Keep track of where the elevator is */
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atomic_t scan_queue; /* Set to non-zero when pkt_handle_queue */
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/* needs to be run. */
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mempool_t rb_pool; /* mempool for pkt_rb_node allocations */
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struct packet_iosched iosched;
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struct gendisk *disk;
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int write_congestion_off;
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int write_congestion_on;
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struct device *dev; /* sysfs pktcdvd[0-7] dev */
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struct dentry *dfs_d_root; /* debugfs: devname directory */
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struct dentry *dfs_f_info; /* debugfs: info file */
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};
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#endif /* __PKTCDVD_H */
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