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Diffstat (limited to 'drivers/scsi/st.c')
| -rw-r--r-- | drivers/scsi/st.c | 4438 |
1 files changed, 4438 insertions, 0 deletions
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c new file mode 100644 index 0000000..265d1ee --- /dev/null +++ b/drivers/scsi/st.c @@ -0,0 +1,4438 @@ +/* + SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying + file Documentation/scsi/st.txt for more information. + + History: + Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara. + Contribution and ideas from several people including (in alphabetical + order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk, + Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky, + Michael Schaefer, J"org Weule, and Eric Youngdale. + + Copyright 1992 - 2005 Kai Makisara + email Kai.Makisara@kolumbus.fi + + Some small formal changes - aeb, 950809 + + Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support + */ + +static char *verstr = "20050312"; + +#include <linux/module.h> + +#include <linux/fs.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/mtio.h> +#include <linux/ioctl.h> +#include <linux/fcntl.h> +#include <linux/spinlock.h> +#include <linux/blkdev.h> +#include <linux/moduleparam.h> +#include <linux/devfs_fs_kernel.h> +#include <linux/cdev.h> +#include <linux/delay.h> + +#include <asm/uaccess.h> +#include <asm/dma.h> +#include <asm/system.h> + +#include <scsi/scsi.h> +#include <scsi/scsi_dbg.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_driver.h> +#include <scsi/scsi_eh.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi_ioctl.h> +#include <scsi/scsi_request.h> + + +/* The driver prints some debugging information on the console if DEBUG + is defined and non-zero. */ +#define DEBUG 0 + +#if DEBUG +/* The message level for the debug messages is currently set to KERN_NOTICE + so that people can easily see the messages. Later when the debugging messages + in the drivers are more widely classified, this may be changed to KERN_DEBUG. */ +#define ST_DEB_MSG KERN_NOTICE +#define DEB(a) a +#define DEBC(a) if (debugging) { a ; } +#else +#define DEB(a) +#define DEBC(a) +#endif + +#define ST_KILOBYTE 1024 + +#include "st_options.h" +#include "st.h" + +static int buffer_kbs; +static int max_sg_segs; +static int try_direct_io = TRY_DIRECT_IO; +static int try_rdio = 1; +static int try_wdio = 1; + +static int st_dev_max; +static int st_nr_dev; + +static struct class_simple *st_sysfs_class; + +MODULE_AUTHOR("Kai Makisara"); +MODULE_DESCRIPTION("SCSI Tape Driver"); +MODULE_LICENSE("GPL"); + +/* Set 'perm' (4th argument) to 0 to disable module_param's definition + * of sysfs parameters (which module_param doesn't yet support). + * Sysfs parameters defined explicitly later. + */ +module_param_named(buffer_kbs, buffer_kbs, int, 0); +MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)"); +module_param_named(max_sg_segs, max_sg_segs, int, 0); +MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)"); +module_param_named(try_direct_io, try_direct_io, int, 0); +MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)"); + +/* Extra parameters for testing */ +module_param_named(try_rdio, try_rdio, int, 0); +MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible"); +module_param_named(try_wdio, try_wdio, int, 0); +MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible"); + +#ifndef MODULE +static int write_threshold_kbs; /* retained for compatibility */ +static struct st_dev_parm { + char *name; + int *val; +} parms[] __initdata = { + { + "buffer_kbs", &buffer_kbs + }, + { /* Retained for compatibility with 2.4 */ + "write_threshold_kbs", &write_threshold_kbs + }, + { + "max_sg_segs", NULL + }, + { + "try_direct_io", &try_direct_io + } +}; +#endif + +/* Restrict the number of modes so that names for all are assigned */ +#if ST_NBR_MODES > 16 +#error "Maximum number of modes is 16" +#endif +/* Bit reversed order to get same names for same minors with all + mode counts */ +static char *st_formats[] = { + "", "r", "k", "s", "l", "t", "o", "u", + "m", "v", "p", "x", "a", "y", "q", "z"}; + +/* The default definitions have been moved to st_options.h */ + +#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE) + +/* The buffer size should fit into the 24 bits for length in the + 6-byte SCSI read and write commands. */ +#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1) +#error "Buffer size should not exceed (2 << 24 - 1) bytes!" +#endif + +static int debugging = DEBUG; + +#define MAX_RETRIES 0 +#define MAX_WRITE_RETRIES 0 +#define MAX_READY_RETRIES 0 +#define NO_TAPE NOT_READY + +#define ST_TIMEOUT (900 * HZ) +#define ST_LONG_TIMEOUT (14000 * HZ) + +/* Remove mode bits and auto-rewind bit (7) */ +#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \ + (iminor(x) & ~(-1 << ST_MODE_SHIFT)) ) +#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT) + +/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */ +#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \ + (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) ) + +/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower + 24 bits) */ +#define SET_DENS_AND_BLK 0x10001 + +static DEFINE_RWLOCK(st_dev_arr_lock); + +static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE; +static int st_max_sg_segs = ST_MAX_SG; + +static struct scsi_tape **scsi_tapes = NULL; + +static int modes_defined; + +static struct st_buffer *new_tape_buffer(int, int, int); +static int enlarge_buffer(struct st_buffer *, int, int); +static void normalize_buffer(struct st_buffer *); +static int append_to_buffer(const char __user *, struct st_buffer *, int); +static int from_buffer(struct st_buffer *, char __user *, int); +static void move_buffer_data(struct st_buffer *, int); +static void buf_to_sg(struct st_buffer *, unsigned int); + +static int st_map_user_pages(struct scatterlist *, const unsigned int, + unsigned long, size_t, int, unsigned long); +static int sgl_map_user_pages(struct scatterlist *, const unsigned int, + unsigned long, size_t, int); +static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int); + +static int st_probe(struct device *); +static int st_remove(struct device *); +static int st_init_command(struct scsi_cmnd *); + +static void do_create_driverfs_files(void); +static void do_remove_driverfs_files(void); +static void do_create_class_files(struct scsi_tape *, int, int); + +static struct scsi_driver st_template = { + .owner = THIS_MODULE, + .gendrv = { + .name = "st", + .probe = st_probe, + .remove = st_remove, + }, + .init_command = st_init_command, +}; + +static int st_compression(struct scsi_tape *, int); + +static int find_partition(struct scsi_tape *); +static int switch_partition(struct scsi_tape *); + +static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long); + + +#include "osst_detect.h" +#ifndef SIGS_FROM_OSST +#define SIGS_FROM_OSST \ + {"OnStream", "SC-", "", "osst"}, \ + {"OnStream", "DI-", "", "osst"}, \ + {"OnStream", "DP-", "", "osst"}, \ + {"OnStream", "USB", "", "osst"}, \ + {"OnStream", "FW-", "", "osst"} +#endif + +struct st_reject_data { + char *vendor; + char *model; + char *rev; + char *driver_hint; /* Name of the correct driver, NULL if unknown */ +}; + +static struct st_reject_data reject_list[] = { + /* {"XXX", "Yy-", "", NULL}, example */ + SIGS_FROM_OSST, + {NULL, }}; + +/* If the device signature is on the list of incompatible drives, the + function returns a pointer to the name of the correct driver (if known) */ +static char * st_incompatible(struct scsi_device* SDp) +{ + struct st_reject_data *rp; + + for (rp=&(reject_list[0]); rp->vendor != NULL; rp++) + if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) && + !strncmp(rp->model, SDp->model, strlen(rp->model)) && + !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) { + if (rp->driver_hint) + return rp->driver_hint; + else + return "unknown"; + } + return NULL; +} + + +static inline char *tape_name(struct scsi_tape *tape) +{ + return tape->disk->disk_name; +} + + +static void st_analyze_sense(struct scsi_request *SRpnt, struct st_cmdstatus *s) +{ + const u8 *ucp; + const u8 *sense = SRpnt->sr_sense_buffer; + + s->have_sense = scsi_request_normalize_sense(SRpnt, &s->sense_hdr); + s->flags = 0; + + if (s->have_sense) { + s->deferred = 0; + s->remainder_valid = + scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64); + switch (sense[0] & 0x7f) { + case 0x71: + s->deferred = 1; + case 0x70: + s->fixed_format = 1; + s->flags = sense[2] & 0xe0; + break; + case 0x73: + s->deferred = 1; + case 0x72: + s->fixed_format = 0; + ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4); + s->flags = ucp ? (ucp[3] & 0xe0) : 0; + break; + } + } +} + + +/* Convert the result to success code */ +static int st_chk_result(struct scsi_tape *STp, struct scsi_request * SRpnt) +{ + int result = SRpnt->sr_result; + u8 scode; + DEB(const char *stp;) + char *name = tape_name(STp); + struct st_cmdstatus *cmdstatp; + + if (!result) + return 0; + + cmdstatp = &STp->buffer->cmdstat; + st_analyze_sense(STp->buffer->last_SRpnt, cmdstatp); + + if (cmdstatp->have_sense) + scode = STp->buffer->cmdstat.sense_hdr.sense_key; + else + scode = 0; + + DEB( + if (debugging) { + printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n", + name, result, + SRpnt->sr_cmnd[0], SRpnt->sr_cmnd[1], SRpnt->sr_cmnd[2], + SRpnt->sr_cmnd[3], SRpnt->sr_cmnd[4], SRpnt->sr_cmnd[5], + SRpnt->sr_bufflen); + if (cmdstatp->have_sense) + scsi_print_req_sense("st", SRpnt); + } ) /* end DEB */ + if (!debugging) { /* Abnormal conditions for tape */ + if (!cmdstatp->have_sense) + printk(KERN_WARNING + "%s: Error %x (sugg. bt 0x%x, driver bt 0x%x, host bt 0x%x).\n", + name, result, suggestion(result), + driver_byte(result) & DRIVER_MASK, host_byte(result)); + else if (cmdstatp->have_sense && + scode != NO_SENSE && + scode != RECOVERED_ERROR && + /* scode != UNIT_ATTENTION && */ + scode != BLANK_CHECK && + scode != VOLUME_OVERFLOW && + SRpnt->sr_cmnd[0] != MODE_SENSE && + SRpnt->sr_cmnd[0] != TEST_UNIT_READY) { + printk(KERN_WARNING "%s: Error with sense data: ", name); + scsi_print_req_sense("st", SRpnt); + } + } + + if (cmdstatp->fixed_format && + STp->cln_mode >= EXTENDED_SENSE_START) { /* Only fixed format sense */ + if (STp->cln_sense_value) + STp->cleaning_req |= ((SRpnt->sr_sense_buffer[STp->cln_mode] & + STp->cln_sense_mask) == STp->cln_sense_value); + else + STp->cleaning_req |= ((SRpnt->sr_sense_buffer[STp->cln_mode] & + STp->cln_sense_mask) != 0); + } + if (cmdstatp->have_sense && + cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17) + STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */ + + STp->pos_unknown |= STp->device->was_reset; + + if (cmdstatp->have_sense && + scode == RECOVERED_ERROR +#if ST_RECOVERED_WRITE_FATAL + && SRpnt->sr_cmnd[0] != WRITE_6 + && SRpnt->sr_cmnd[0] != WRITE_FILEMARKS +#endif + ) { + STp->recover_count++; + STp->recover_reg++; + + DEB( + if (debugging) { + if (SRpnt->sr_cmnd[0] == READ_6) + stp = "read"; + else if (SRpnt->sr_cmnd[0] == WRITE_6) + stp = "write"; + else + stp = "ioctl"; + printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp, + STp->recover_count); + } ) /* end DEB */ + + if (cmdstatp->flags == 0) + return 0; + } + return (-EIO); +} + + +/* Wakeup from interrupt */ +static void st_sleep_done(struct scsi_cmnd * SCpnt) +{ + struct scsi_tape *STp = container_of(SCpnt->request->rq_disk->private_data, + struct scsi_tape, driver); + + (STp->buffer)->cmdstat.midlevel_result = SCpnt->result; + SCpnt->request->rq_status = RQ_SCSI_DONE; + (STp->buffer)->last_SRpnt = SCpnt->sc_request; + DEB( STp->write_pending = 0; ) + + complete(SCpnt->request->waiting); +} + +/* Do the scsi command. Waits until command performed if do_wait is true. + Otherwise write_behind_check() is used to check that the command + has finished. */ +static struct scsi_request * +st_do_scsi(struct scsi_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd, + int bytes, int direction, int timeout, int retries, int do_wait) +{ + unsigned char *bp; + + if (SRpnt == NULL) { + SRpnt = scsi_allocate_request(STp->device, GFP_ATOMIC); + if (SRpnt == NULL) { + DEBC( printk(KERN_ERR "%s: Can't get SCSI request.\n", + tape_name(STp)); ); + if (signal_pending(current)) + (STp->buffer)->syscall_result = (-EINTR); + else + (STp->buffer)->syscall_result = (-EBUSY); + return NULL; + } + } + + init_completion(&STp->wait); + SRpnt->sr_use_sg = STp->buffer->do_dio || (bytes > (STp->buffer)->frp[0].length); + if (SRpnt->sr_use_sg) { + if (!STp->buffer->do_dio) + buf_to_sg(STp->buffer, bytes); + SRpnt->sr_use_sg = (STp->buffer)->sg_segs; + bp = (char *) &((STp->buffer)->sg[0]); + } else + bp = (STp->buffer)->b_data; + SRpnt->sr_data_direction = direction; + SRpnt->sr_cmd_len = 0; + SRpnt->sr_request->waiting = &(STp->wait); + SRpnt->sr_request->rq_status = RQ_SCSI_BUSY; + SRpnt->sr_request->rq_disk = STp->disk; + STp->buffer->cmdstat.have_sense = 0; + + scsi_do_req(SRpnt, (void *) cmd, bp, bytes, + st_sleep_done, timeout, retries); + + if (do_wait) { + wait_for_completion(SRpnt->sr_request->waiting); + SRpnt->sr_request->waiting = NULL; + (STp->buffer)->syscall_result = st_chk_result(STp, SRpnt); + } + return SRpnt; +} + + +/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if + write has been correct but EOM early warning reached, -EIO if write ended in + error or zero if write successful. Asynchronous writes are used only in + variable block mode. */ +static int write_behind_check(struct scsi_tape * STp) +{ + int retval = 0; + struct st_buffer *STbuffer; + struct st_partstat *STps; + struct st_cmdstatus *cmdstatp; + + STbuffer = STp->buffer; + if (!STbuffer->writing) + return 0; + + DEB( + if (STp->write_pending) + STp->nbr_waits++; + else + STp->nbr_finished++; + ) /* end DEB */ + + wait_for_completion(&(STp->wait)); + (STp->buffer)->last_SRpnt->sr_request->waiting = NULL; + + (STp->buffer)->syscall_result = st_chk_result(STp, (STp->buffer)->last_SRpnt); + scsi_release_request((STp->buffer)->last_SRpnt); + + STbuffer->buffer_bytes -= STbuffer->writing; + STps = &(STp->ps[STp->partition]); + if (STps->drv_block >= 0) { + if (STp->block_size == 0) + STps->drv_block++; + else + STps->drv_block += STbuffer->writing / STp->block_size; + } + + cmdstatp = &STbuffer->cmdstat; + if (STbuffer->syscall_result) { + retval = -EIO; + if (cmdstatp->have_sense && !cmdstatp->deferred && + (cmdstatp->flags & SENSE_EOM) && + (cmdstatp->sense_hdr.sense_key == NO_SENSE || + cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) { + /* EOM at write-behind, has all data been written? */ + if (!cmdstatp->remainder_valid || + cmdstatp->uremainder64 == 0) + retval = -ENOSPC; + } + if (retval == -EIO) + STps->drv_block = -1; + } + STbuffer->writing = 0; + + DEB(if (debugging && retval) + printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n", + tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */ + + return retval; +} + + +/* Step over EOF if it has been inadvertently crossed (ioctl not used because + it messes up the block number). */ +static int cross_eof(struct scsi_tape * STp, int forward) +{ + struct scsi_request *SRpnt; + unsigned char cmd[MAX_COMMAND_SIZE]; + + cmd[0] = SPACE; + cmd[1] = 0x01; /* Space FileMarks */ + if (forward) { + cmd[2] = cmd[3] = 0; + cmd[4] = 1; + } else + cmd[2] = cmd[3] = cmd[4] = 0xff; /* -1 filemarks */ + cmd[5] = 0; + + DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n", + tape_name(STp), forward ? "forward" : "backward")); + + SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE, + STp->device->timeout, MAX_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + scsi_release_request(SRpnt); + SRpnt = NULL; + + if ((STp->buffer)->cmdstat.midlevel_result != 0) + printk(KERN_ERR "%s: Stepping over filemark %s failed.\n", + tape_name(STp), forward ? "forward" : "backward"); + + return (STp->buffer)->syscall_result; +} + + +/* Flush the write buffer (never need to write if variable blocksize). */ +static int flush_write_buffer(struct scsi_tape * STp) +{ + int offset, transfer, blks; + int result; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + struct st_partstat *STps; + + result = write_behind_check(STp); + if (result) + return result; + + result = 0; + if (STp->dirty == 1) { + + offset = (STp->buffer)->buffer_bytes; + transfer = ((offset + STp->block_size - 1) / + STp->block_size) * STp->block_size; + DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n", + tape_name(STp), transfer)); + + memset((STp->buffer)->b_data + offset, 0, transfer - offset); + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = WRITE_6; + cmd[1] = 1; + blks = transfer / STp->block_size; + cmd[2] = blks >> 16; + cmd[3] = blks >> 8; + cmd[4] = blks; + + SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE, + STp->device->timeout, MAX_WRITE_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + STps = &(STp->ps[STp->partition]); + if ((STp->buffer)->syscall_result != 0) { + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + if (cmdstatp->have_sense && !cmdstatp->deferred && + (cmdstatp->flags & SENSE_EOM) && + (cmdstatp->sense_hdr.sense_key == NO_SENSE || + cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) && + (!cmdstatp->remainder_valid || + cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */ + STp->dirty = 0; + (STp->buffer)->buffer_bytes = 0; + if (STps->drv_block >= 0) + STps->drv_block += blks; + result = (-ENOSPC); + } else { + printk(KERN_ERR "%s: Error on flush.\n", + tape_name(STp)); + STps->drv_block = (-1); + result = (-EIO); + } + } else { + if (STps->drv_block >= 0) + STps->drv_block += blks; + STp->dirty = 0; + (STp->buffer)->buffer_bytes = 0; + } + scsi_release_request(SRpnt); + SRpnt = NULL; + } + return result; +} + + +/* Flush the tape buffer. The tape will be positioned correctly unless + seek_next is true. */ +static int flush_buffer(struct scsi_tape *STp, int seek_next) +{ + int backspace, result; + struct st_buffer *STbuffer; + struct st_partstat *STps; + + STbuffer = STp->buffer; + + /* + * If there was a bus reset, block further access + * to this device. + */ + if (STp->pos_unknown) + return (-EIO); + + if (STp->ready != ST_READY) + return 0; + STps = &(STp->ps[STp->partition]); + if (STps->rw == ST_WRITING) /* Writing */ + return flush_write_buffer(STp); + + if (STp->block_size == 0) + return 0; + + backspace = ((STp->buffer)->buffer_bytes + + (STp->buffer)->read_pointer) / STp->block_size - + ((STp->buffer)->read_pointer + STp->block_size - 1) / + STp->block_size; + (STp->buffer)->buffer_bytes = 0; + (STp->buffer)->read_pointer = 0; + result = 0; + if (!seek_next) { + if (STps->eof == ST_FM_HIT) { + result = cross_eof(STp, 0); /* Back over the EOF hit */ + if (!result) + STps->eof = ST_NOEOF; + else { + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + } + } + if (!result && backspace > 0) + result = st_int_ioctl(STp, MTBSR, backspace); + } else if (STps->eof == ST_FM_HIT) { + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + STps->eof = ST_NOEOF; + } + return result; + +} + +/* Set the mode parameters */ +static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm) +{ + int set_it = 0; + unsigned long arg; + char *name = tape_name(STp); + + if (!STp->density_changed && + STm->default_density >= 0 && + STm->default_density != STp->density) { + arg = STm->default_density; + set_it = 1; + } else + arg = STp->density; + arg <<= MT_ST_DENSITY_SHIFT; + if (!STp->blksize_changed && + STm->default_blksize >= 0 && + STm->default_blksize != STp->block_size) { + arg |= STm->default_blksize; + set_it = 1; + } else + arg |= STp->block_size; + if (set_it && + st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) { + printk(KERN_WARNING + "%s: Can't set default block size to %d bytes and density %x.\n", + name, STm->default_blksize, STm->default_density); + if (modes_defined) + return (-EINVAL); + } + return 0; +} + + +/* Lock or unlock the drive door. Don't use when scsi_request allocated. */ +static int do_door_lock(struct scsi_tape * STp, int do_lock) +{ + int retval, cmd; + DEB(char *name = tape_name(STp);) + + + cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK; + DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name, + do_lock ? "L" : "Unl")); + retval = scsi_ioctl(STp->device, cmd, NULL); + if (!retval) { + STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED; + } + else { + STp->door_locked = ST_LOCK_FAILS; + } + return retval; +} + + +/* Set the internal state after reset */ +static void reset_state(struct scsi_tape *STp) +{ + int i; + struct st_partstat *STps; + + STp->pos_unknown = 0; + for (i = 0; i < ST_NBR_PARTITIONS; i++) { + STps = &(STp->ps[i]); + STps->rw = ST_IDLE; + STps->eof = ST_NOEOF; + STps->at_sm = 0; + STps->last_block_valid = 0; + STps->drv_block = -1; + STps->drv_file = -1; + } + if (STp->can_partitions) { + STp->partition = find_partition(STp); + if (STp->partition < 0) + STp->partition = 0; + STp->new_partition = STp->partition; + } +} + +/* Test if the drive is ready. Returns either one of the codes below or a negative system + error code. */ +#define CHKRES_READY 0 +#define CHKRES_NEW_SESSION 1 +#define CHKRES_NOT_READY 2 +#define CHKRES_NO_TAPE 3 + +#define MAX_ATTENTIONS 10 + +static int test_ready(struct scsi_tape *STp, int do_wait) +{ + int attentions, waits, max_wait, scode; + int retval = CHKRES_READY, new_session = 0; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt = NULL; + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + max_wait = do_wait ? ST_BLOCK_SECONDS : 0; + + for (attentions=waits=0; ; ) { + memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE); + cmd[0] = TEST_UNIT_READY; + SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE, + STp->long_timeout, MAX_READY_RETRIES, 1); + + if (!SRpnt) { + retval = (STp->buffer)->syscall_result; + break; + } + + if (cmdstatp->have_sense) { + + scode = cmdstatp->sense_hdr.sense_key; + + if (scode == UNIT_ATTENTION) { /* New media? */ + new_session = 1; + if (attentions < MAX_ATTENTIONS) { + attentions++; + continue; + } + else { + retval = (-EIO); + break; + } + } + + if (scode == NOT_READY) { + if (waits < max_wait) { + if (msleep_interruptible(1000)) { + retval = (-EINTR); + break; + } + waits++; + continue; + } + else { + if ((STp->device)->scsi_level >= SCSI_2 && + cmdstatp->sense_hdr.asc == 0x3a) /* Check ASC */ + retval = CHKRES_NO_TAPE; + else + retval = CHKRES_NOT_READY; + break; + } + } + } + + retval = (STp->buffer)->syscall_result; + if (!retval) + retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY; + break; + } + + if (SRpnt != NULL) + scsi_release_request(SRpnt); + return retval; +} + + +/* See if the drive is ready and gather information about the tape. Return values: + < 0 negative error code from errno.h + 0 drive ready + 1 drive not ready (possibly no tape) +*/ +static int check_tape(struct scsi_tape *STp, struct file *filp) +{ + int i, retval, new_session = 0, do_wait; + unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning; + unsigned short st_flags = filp->f_flags; + struct scsi_request *SRpnt = NULL; + struct st_modedef *STm; + struct st_partstat *STps; + char *name = tape_name(STp); + struct inode *inode = filp->f_dentry->d_inode; + int mode = TAPE_MODE(inode); + + STp->ready = ST_READY; + + if (mode != STp->current_mode) { + DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n", + name, STp->current_mode, mode)); + new_session = 1; + STp->current_mode = mode; + } + STm = &(STp->modes[STp->current_mode]); + + saved_cleaning = STp->cleaning_req; + STp->cleaning_req = 0; + + do_wait = ((filp->f_flags & O_NONBLOCK) == 0); + retval = test_ready(STp, do_wait); + + if (retval < 0) + goto err_out; + + if (retval == CHKRES_NEW_SESSION) { + STp->pos_unknown = 0; + STp->partition = STp->new_partition = 0; + if (STp->can_partitions) + STp->nbr_partitions = 1; /* This guess will be updated later + if necessary */ + for (i = 0; i < ST_NBR_PARTITIONS; i++) { + STps = &(STp->ps[i]); + STps->rw = ST_IDLE; + STps->eof = ST_NOEOF; + STps->at_sm = 0; + STps->last_block_valid = 0; + STps->drv_block = 0; + STps->drv_file = 0; + } + new_session = 1; + } + else { + STp->cleaning_req |= saved_cleaning; + + if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) { + if (retval == CHKRES_NO_TAPE) + STp->ready = ST_NO_TAPE; + else + STp->ready = ST_NOT_READY; + + STp->density = 0; /* Clear the erroneous "residue" */ + STp->write_prot = 0; + STp->block_size = 0; + STp->ps[0].drv_file = STp->ps[0].drv_block = (-1); + STp->partition = STp->new_partition = 0; + STp->door_locked = ST_UNLOCKED; + return CHKRES_NOT_READY; + } + } + + if (STp->omit_blklims) + STp->min_block = STp->max_block = (-1); + else { + memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE); + cmd[0] = READ_BLOCK_LIMITS; + + SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE, + STp->device->timeout, MAX_READY_RETRIES, 1); + if (!SRpnt) { + retval = (STp->buffer)->syscall_result; + goto err_out; + } + + if (!SRpnt->sr_result && !STp->buffer->cmdstat.have_sense) { + STp->max_block = ((STp->buffer)->b_data[1] << 16) | + ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3]; + STp->min_block = ((STp->buffer)->b_data[4] << 8) | + (STp->buffer)->b_data[5]; + if ( DEB( debugging || ) !STp->inited) + printk(KERN_WARNING + "%s: Block limits %d - %d bytes.\n", name, + STp->min_block, STp->max_block); + } else { + STp->min_block = STp->max_block = (-1); + DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n", + name)); + } + } + + memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE); + cmd[0] = MODE_SENSE; + cmd[4] = 12; + + SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE, + STp->device->timeout, MAX_READY_RETRIES, 1); + if (!SRpnt) { + retval = (STp->buffer)->syscall_result; + goto err_out; + } + + if ((STp->buffer)->syscall_result != 0) { + DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name)); + STp->block_size = ST_DEFAULT_BLOCK; /* Educated guess (?) */ + (STp->buffer)->syscall_result = 0; /* Prevent error propagation */ + STp->drv_write_prot = 0; + } else { + DEBC(printk(ST_DEB_MSG + "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n", + name, + (STp->buffer)->b_data[0], (STp->buffer)->b_data[1], + (STp->buffer)->b_data[2], (STp->buffer)->b_data[3])); + + if ((STp->buffer)->b_data[3] >= 8) { + STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7; + STp->density = (STp->buffer)->b_data[4]; + STp->block_size = (STp->buffer)->b_data[9] * 65536 + + (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11]; + DEBC(printk(ST_DEB_MSG + "%s: Density %x, tape length: %x, drv buffer: %d\n", + name, STp->density, (STp->buffer)->b_data[5] * 65536 + + (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7], + STp->drv_buffer)); + } + STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0; + } + scsi_release_request(SRpnt); + SRpnt = NULL; + STp->inited = 1; + + if (STp->block_size > 0) + (STp->buffer)->buffer_blocks = + (STp->buffer)->buffer_size / STp->block_size; + else + (STp->buffer)->buffer_blocks = 1; + (STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0; + + DEBC(printk(ST_DEB_MSG + "%s: Block size: %d, buffer size: %d (%d blocks).\n", name, + STp->block_size, (STp->buffer)->buffer_size, + (STp->buffer)->buffer_blocks)); + + if (STp->drv_write_prot) { + STp->write_prot = 1; + + DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name)); + + if (do_wait && + ((st_flags & O_ACCMODE) == O_WRONLY || + (st_flags & O_ACCMODE) == O_RDWR)) { + retval = (-EROFS); + goto err_out; + } + } + + if (STp->can_partitions && STp->nbr_partitions < 1) { + /* This code is reached when the device is opened for the first time + after the driver has been initialized with tape in the drive and the + partition support has been enabled. */ + DEBC(printk(ST_DEB_MSG + "%s: Updating partition number in status.\n", name)); + if ((STp->partition = find_partition(STp)) < 0) { + retval = STp->partition; + goto err_out; + } + STp->new_partition = STp->partition; + STp->nbr_partitions = 1; /* This guess will be updated when necessary */ + } + + if (new_session) { /* Change the drive parameters for the new mode */ + STp->density_changed = STp->blksize_changed = 0; + STp->compression_changed = 0; + if (!(STm->defaults_for_writes) && + (retval = set_mode_densblk(STp, STm)) < 0) + goto err_out; + + if (STp->default_drvbuffer != 0xff) { + if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer)) + printk(KERN_WARNING + "%s: Can't set default drive buffering to %d.\n", + name, STp->default_drvbuffer); + } + } + + return CHKRES_READY; + + err_out: + return retval; +} + + + /* Open the device. Needs to be called with BKL only because of incrementing the SCSI host + module count. */ +static int st_open(struct inode *inode, struct file *filp) +{ + int i, retval = (-EIO); + struct scsi_tape *STp; + struct st_partstat *STps; + int dev = TAPE_NR(inode); + char *name; + + /* + * We really want to do nonseekable_open(inode, filp); here, but some + * versions of tar incorrectly call lseek on tapes and bail out if that + * fails. So we disallow pread() and pwrite(), but permit lseeks. + */ + filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); + + write_lock(&st_dev_arr_lock); + if (dev >= st_dev_max || scsi_tapes == NULL || + ((STp = scsi_tapes[dev]) == NULL)) { + write_unlock(&st_dev_arr_lock); + return (-ENXIO); + } + filp->private_data = STp; + name = tape_name(STp); + + if (STp->in_use) { + write_unlock(&st_dev_arr_lock); + DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); ) + return (-EBUSY); + } + + if(scsi_device_get(STp->device)) { + write_unlock(&st_dev_arr_lock); + return (-ENXIO); + } + STp->in_use = 1; + write_unlock(&st_dev_arr_lock); + STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0; + + if (!scsi_block_when_processing_errors(STp->device)) { + retval = (-ENXIO); + goto err_out; + } + + /* See that we have at least a one page buffer available */ + if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) { + printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n", + name); + retval = (-EOVERFLOW); + goto err_out; + } + + (STp->buffer)->writing = 0; + (STp->buffer)->syscall_result = 0; + + STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY); + + STp->dirty = 0; + for (i = 0; i < ST_NBR_PARTITIONS; i++) { + STps = &(STp->ps[i]); + STps->rw = ST_IDLE; + } + STp->recover_count = 0; + DEB( STp->nbr_waits = STp->nbr_finished = 0; + STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = STp->nbr_combinable = 0; ) + + retval = check_tape(STp, filp); + if (retval < 0) + goto err_out; + if ((filp->f_flags & O_NONBLOCK) == 0 && + retval != CHKRES_READY) { + retval = (-EIO); + goto err_out; + } + return 0; + + err_out: + normalize_buffer(STp->buffer); + STp->in_use = 0; + scsi_device_put(STp->device); + return retval; + +} + + +/* Flush the tape buffer before close */ +static int st_flush(struct file *filp) +{ + int result = 0, result2; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + struct scsi_tape *STp = filp->private_data; + struct st_modedef *STm = &(STp->modes[STp->current_mode]); + struct st_partstat *STps = &(STp->ps[STp->partition]); + char *name = tape_name(STp); + + if (file_count(filp) > 1) + return 0; + + if (STps->rw == ST_WRITING && !STp->pos_unknown) { + result = flush_write_buffer(STp); + if (result != 0 && result != (-ENOSPC)) + goto out; + } + + if (STp->can_partitions && + (result2 = switch_partition(STp)) < 0) { + DEBC(printk(ST_DEB_MSG + "%s: switch_partition at close failed.\n", name)); + if (result == 0) + result = result2; + goto out; + } + + DEBC( if (STp->nbr_requests) + printk(KERN_WARNING "%s: Number of r/w requests %d, dio used in %d, pages %d (%d).\n", + name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages, STp->nbr_combinable)); + + if (STps->rw == ST_WRITING && !STp->pos_unknown) { + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n", + name, STp->nbr_waits, STp->nbr_finished); + ) + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = WRITE_FILEMARKS; + cmd[4] = 1 + STp->two_fm; + + SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE, + STp->device->timeout, MAX_WRITE_RETRIES, 1); + if (!SRpnt) { + result = (STp->buffer)->syscall_result; + goto out; + } + + if (STp->buffer->syscall_result == 0 || + (cmdstatp->have_sense && !cmdstatp->deferred && + (cmdstatp->flags & SENSE_EOM) && + (cmdstatp->sense_hdr.sense_key == NO_SENSE || + cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) && + (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) { + /* Write successful at EOM */ + scsi_release_request(SRpnt); + SRpnt = NULL; + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + if (STp->two_fm) + cross_eof(STp, 0); + STps->eof = ST_FM; + } + else { /* Write error */ + scsi_release_request(SRpnt); + SRpnt = NULL; + printk(KERN_ERR "%s: Error on write filemark.\n", name); + if (result == 0) + result = (-EIO); + } + + DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n", + name, cmd[4])); + } else if (!STp->rew_at_close) { + STps = &(STp->ps[STp->partition]); + if (!STm->sysv || STps->rw != ST_READING) { + if (STp->can_bsr) + result = flush_buffer(STp, 0); + else if (STps->eof == ST_FM_HIT) { + result = cross_eof(STp, 0); + if (result) { + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + STps->eof = ST_FM; + } else + STps->eof = ST_NOEOF; + } + } else if ((STps->eof == ST_NOEOF && + !(result = cross_eof(STp, 1))) || + STps->eof == ST_FM_HIT) { + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + STps->eof = ST_FM; + } + } + + out: + if (STp->rew_at_close) { + result2 = st_int_ioctl(STp, MTREW, 1); + if (result == 0) + result = result2; + } + return result; +} + + +/* Close the device and release it. BKL is not needed: this is the only thread + accessing this tape. */ +static int st_release(struct inode *inode, struct file *filp) +{ + int result = 0; + struct scsi_tape *STp = filp->private_data; + + if (STp->door_locked == ST_LOCKED_AUTO) + do_door_lock(STp, 0); + + normalize_buffer(STp->buffer); + write_lock(&st_dev_arr_lock); + STp->in_use = 0; + write_unlock(&st_dev_arr_lock); + scsi_device_put(STp->device); + + return result; +} + +/* The checks common to both reading and writing */ +static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count) +{ + ssize_t retval = 0; + + /* + * If we are in the middle of error recovery, don't let anyone + * else try and use this device. Also, if error recovery fails, it + * may try and take the device offline, in which case all further + * access to the device is prohibited. + */ + if (!scsi_block_when_processing_errors(STp->device)) { + retval = (-ENXIO); + goto out; + } + + if (STp->ready != ST_READY) { + if (STp->ready == ST_NO_TAPE) + retval = (-ENOMEDIUM); + else + retval = (-EIO); + goto out; + } + + if (! STp->modes[STp->current_mode].defined) { + retval = (-ENXIO); + goto out; + } + + + /* + * If there was a bus reset, block further access + * to this device. + */ + if (STp->pos_unknown) { + retval = (-EIO); + goto out; + } + + if (count == 0) + goto out; + + DEB( + if (!STp->in_use) { + printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp)); + retval = (-EIO); + goto out; + } ) /* end DEB */ + + if (STp->can_partitions && + (retval = switch_partition(STp)) < 0) + goto out; + + if (STp->block_size == 0 && STp->max_block > 0 && + (count < STp->min_block || count > STp->max_block)) { + retval = (-EINVAL); + goto out; + } + + if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED && + !do_door_lock(STp, 1)) + STp->door_locked = ST_LOCKED_AUTO; + + out: + return retval; +} + + +static int setup_buffering(struct scsi_tape *STp, const char __user *buf, + size_t count, int is_read) +{ + int i, bufsize, retval = 0; + struct st_buffer *STbp = STp->buffer; + + if (is_read) + i = STp->try_dio && try_rdio; + else + i = STp->try_dio && try_wdio; + if (i && ((unsigned long)buf & queue_dma_alignment( + STp->device->request_queue)) == 0) { + i = st_map_user_pages(&(STbp->sg[0]), STbp->use_sg, + (unsigned long)buf, count, (is_read ? READ : WRITE), + STp->max_pfn); + if (i > 0) { + STbp->do_dio = i; + STbp->buffer_bytes = 0; /* can be used as transfer counter */ + } + else + STbp->do_dio = 0; /* fall back to buffering with any error */ + STbp->sg_segs = STbp->do_dio; + STbp->frp_sg_current = 0; + DEB( + if (STbp->do_dio) { + STp->nbr_dio++; + STp->nbr_pages += STbp->do_dio; + for (i=1; i < STbp->do_dio; i++) + if (page_to_pfn(STbp->sg[i].page) == page_to_pfn(STbp->sg[i-1].page) + 1) + STp->nbr_combinable++; + } + ) + } else + STbp->do_dio = 0; + DEB( STp->nbr_requests++; ) + + if (!STbp->do_dio) { + if (STp->block_size) + bufsize = STp->block_size > st_fixed_buffer_size ? + STp->block_size : st_fixed_buffer_size; + else + bufsize = count; + if (bufsize > STbp->buffer_size && + !enlarge_buffer(STbp, bufsize, STp->restr_dma)) { + printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n", + tape_name(STp), bufsize); + retval = (-EOVERFLOW); + goto out; + } + if (STp->block_size) + STbp->buffer_blocks = bufsize / STp->block_size; + } + + out: + return retval; +} + + +/* Can be called more than once after each setup_buffer() */ +static void release_buffering(struct scsi_tape *STp) +{ + struct st_buffer *STbp; + + STbp = STp->buffer; + if (STbp->do_dio) { + sgl_unmap_user_pages(&(STbp->sg[0]), STbp->do_dio, 0); + STbp->do_dio = 0; + } +} + + +/* Write command */ +static ssize_t +st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) +{ + ssize_t total; + ssize_t i, do_count, blks, transfer; + ssize_t retval; + int undone, retry_eot = 0, scode; + int async_write; + unsigned char cmd[MAX_COMMAND_SIZE]; + const char __user *b_point; + struct scsi_request *SRpnt = NULL; + struct scsi_tape *STp = filp->private_data; + struct st_modedef *STm; + struct st_partstat *STps; + struct st_buffer *STbp; + char *name = tape_name(STp); + + if (down_interruptible(&STp->lock)) + return -ERESTARTSYS; + + retval = rw_checks(STp, filp, count); + if (retval || count == 0) + goto out; + + /* Write must be integral number of blocks */ + if (STp->block_size != 0 && (count % STp->block_size) != 0) { + printk(KERN_WARNING "%s: Write not multiple of tape block size.\n", + name); + retval = (-EINVAL); + goto out; + } + + STm = &(STp->modes[STp->current_mode]); + STps = &(STp->ps[STp->partition]); + + if (STp->write_prot) { + retval = (-EACCES); + goto out; + } + + + if (STps->rw == ST_READING) { + retval = flush_buffer(STp, 0); + if (retval) + goto out; + STps->rw = ST_WRITING; + } else if (STps->rw != ST_WRITING && + STps->drv_file == 0 && STps->drv_block == 0) { + if ((retval = set_mode_densblk(STp, STm)) < 0) + goto out; + if (STm->default_compression != ST_DONT_TOUCH && + !(STp->compression_changed)) { + if (st_compression(STp, (STm->default_compression == ST_YES))) { + printk(KERN_WARNING "%s: Can't set default compression.\n", + name); + if (modes_defined) { + retval = (-EINVAL); + goto out; + } + } + } + } + + STbp = STp->buffer; + i = write_behind_check(STp); + if (i) { + if (i == -ENOSPC) + STps->eof = ST_EOM_OK; + else + STps->eof = ST_EOM_ERROR; + } + + if (STps->eof == ST_EOM_OK) { + STps->eof = ST_EOD_1; /* allow next write */ + retval = (-ENOSPC); + goto out; + } + else if (STps->eof == ST_EOM_ERROR) { + retval = (-EIO); + goto out; + } + + /* Check the buffer readability in cases where copy_user might catch + the problems after some tape movement. */ + if (STp->block_size != 0 && + !STbp->do_dio && + (copy_from_user(&i, buf, 1) != 0 || + copy_from_user(&i, buf + count - 1, 1) != 0)) { + retval = (-EFAULT); + goto out; + } + + retval = setup_buffering(STp, buf, count, 0); + if (retval) + goto out; + + total = count; + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = WRITE_6; + cmd[1] = (STp->block_size != 0); + + STps->rw = ST_WRITING; + + b_point = buf; + while (count > 0 && !retry_eot) { + + if (STbp->do_dio) { + do_count = count; + } + else { + if (STp->block_size == 0) + do_count = count; + else { + do_count = STbp->buffer_blocks * STp->block_size - + STbp->buffer_bytes; + if (do_count > count) + do_count = count; + } + + i = append_to_buffer(b_point, STbp, do_count); + if (i) { + retval = i; + goto out; + } + } + count -= do_count; + b_point += do_count; + + async_write = STp->block_size == 0 && !STbp->do_dio && + STm->do_async_writes && STps->eof < ST_EOM_OK; + + if (STp->block_size != 0 && STm->do_buffer_writes && + !(STp->try_dio && try_wdio) && STps->eof < ST_EOM_OK && + STbp->buffer_bytes < STbp->buffer_size) { + STp->dirty = 1; + /* Don't write a buffer that is not full enough. */ + if (!async_write && count == 0) + break; + } + + retry_write: + if (STp->block_size == 0) + blks = transfer = do_count; + else { + if (!STbp->do_dio) + blks = STbp->buffer_bytes; + else + blks = do_count; + blks /= STp->block_size; + transfer = blks * STp->block_size; + } + cmd[2] = blks >> 16; + cmd[3] = blks >> 8; + cmd[4] = blks; + + SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE, + STp->device->timeout, MAX_WRITE_RETRIES, !async_write); + if (!SRpnt) { + retval = STbp->syscall_result; + goto out; + } + if (async_write) { + STbp->writing = transfer; + STp->dirty = !(STbp->writing == + STbp->buffer_bytes); + SRpnt = NULL; /* Prevent releasing this request! */ + DEB( STp->write_pending = 1; ) + break; + } + + if (STbp->syscall_result != 0) { + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name)); + if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) { + scode = cmdstatp->sense_hdr.sense_key; + if (cmdstatp->remainder_valid) + undone = (int)cmdstatp->uremainder64; + else if (STp->block_size == 0 && + scode == VOLUME_OVERFLOW) + undone = transfer; + else + undone = 0; + if (STp->block_size != 0) + undone *= STp->block_size; + if (undone <= do_count) { + /* Only data from this write is not written */ + count += undone; + do_count -= undone; + if (STp->block_size) + blks = (transfer - undone) / STp->block_size; + STps->eof = ST_EOM_OK; + /* Continue in fixed block mode if all written + in this request but still something left to write + (retval left to zero) + */ + if (STp->block_size == 0 || + undone > 0 || count == 0) + retval = (-ENOSPC); /* EOM within current request */ + DEBC(printk(ST_DEB_MSG + "%s: EOM with %d bytes unwritten.\n", + name, (int)count)); + } else { + /* EOT within data buffered earlier (possible only + in fixed block mode without direct i/o) */ + if (!retry_eot && !cmdstatp->deferred && + (scode == NO_SENSE || scode == RECOVERED_ERROR)) { + move_buffer_data(STp->buffer, transfer - undone); + retry_eot = 1; + if (STps->drv_block >= 0) { + STps->drv_block += (transfer - undone) / + STp->block_size; + } + STps->eof = ST_EOM_OK; + DEBC(printk(ST_DEB_MSG + "%s: Retry write of %d bytes at EOM.\n", + name, STp->buffer->buffer_bytes)); + goto retry_write; + } + else { + /* Either error within data buffered by driver or + failed retry */ + count -= do_count; + blks = do_count = 0; + STps->eof = ST_EOM_ERROR; + STps->drv_block = (-1); /* Too cautious? */ + retval = (-EIO); /* EOM for old data */ + DEBC(printk(ST_DEB_MSG + "%s: EOM with lost data.\n", + name)); + } + } + } else { + count += do_count; + STps->drv_block = (-1); /* Too cautious? */ + retval = (-EIO); + } + + } + + if (STps->drv_block >= 0) { + if (STp->block_size == 0) + STps->drv_block += (do_count > 0); + else + STps->drv_block += blks; + } + + STbp->buffer_bytes = 0; + STp->dirty = 0; + + if (retval || retry_eot) { + if (count < total) + retval = total - count; + goto out; + } + } + + if (STps->eof == ST_EOD_1) + STps->eof = ST_EOM_OK; + else if (STps->eof != ST_EOM_OK) + STps->eof = ST_NOEOF; + retval = total - count; + + out: + if (SRpnt != NULL) + scsi_release_request(SRpnt); + release_buffering(STp); + up(&STp->lock); + + return retval; +} + +/* Read data from the tape. Returns zero in the normal case, one if the + eof status has changed, and the negative error code in case of a + fatal error. Otherwise updates the buffer and the eof state. + + Does release user buffer mapping if it is set. +*/ +static long read_tape(struct scsi_tape *STp, long count, + struct scsi_request ** aSRpnt) +{ + int transfer, blks, bytes; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + struct st_modedef *STm; + struct st_partstat *STps; + struct st_buffer *STbp; + int retval = 0; + char *name = tape_name(STp); + + if (count == 0) + return 0; + + STm = &(STp->modes[STp->current_mode]); + STps = &(STp->ps[STp->partition]); + if (STps->eof == ST_FM_HIT) + return 1; + STbp = STp->buffer; + + if (STp->block_size == 0) + blks = bytes = count; + else { + if (!(STp->try_dio && try_rdio) && STm->do_read_ahead) { + blks = (STp->buffer)->buffer_blocks; + bytes = blks * STp->block_size; + } else { + bytes = count; + if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size) + bytes = (STp->buffer)->buffer_size; + blks = bytes / STp->block_size; + bytes = blks * STp->block_size; + } + } + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = READ_6; + cmd[1] = (STp->block_size != 0); + cmd[2] = blks >> 16; + cmd[3] = blks >> 8; + cmd[4] = blks; + + SRpnt = *aSRpnt; + SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE, + STp->device->timeout, MAX_RETRIES, 1); + release_buffering(STp); + *aSRpnt = SRpnt; + if (!SRpnt) + return STbp->syscall_result; + + STbp->read_pointer = 0; + STps->at_sm = 0; + + /* Something to check */ + if (STbp->syscall_result) { + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + retval = 1; + DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n", + name, + SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[1], + SRpnt->sr_sense_buffer[2], SRpnt->sr_sense_buffer[3], + SRpnt->sr_sense_buffer[4], SRpnt->sr_sense_buffer[5], + SRpnt->sr_sense_buffer[6], SRpnt->sr_sense_buffer[7])); + if (cmdstatp->have_sense) { + + if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK) + cmdstatp->flags &= 0xcf; /* No need for EOM in this case */ + + if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */ + /* Compute the residual count */ + if (cmdstatp->remainder_valid) + transfer = (int)cmdstatp->uremainder64; + else + transfer = 0; + if (STp->block_size == 0 && + cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) + transfer = bytes; + + if (cmdstatp->flags & SENSE_ILI) { /* ILI */ + if (STp->block_size == 0) { + if (transfer <= 0) { + if (transfer < 0) + printk(KERN_NOTICE + "%s: Failed to read %d byte block with %d byte transfer.\n", + name, bytes - transfer, bytes); + if (STps->drv_block >= 0) + STps->drv_block += 1; + STbp->buffer_bytes = 0; + return (-ENOMEM); + } + STbp->buffer_bytes = bytes - transfer; + } else { + scsi_release_request(SRpnt); + SRpnt = *aSRpnt = NULL; + if (transfer == blks) { /* We did not get anything, error */ + printk(KERN_NOTICE "%s: Incorrect block size.\n", name); + if (STps->drv_block >= 0) + STps->drv_block += blks - transfer + 1; + st_int_ioctl(STp, MTBSR, 1); + return (-EIO); + } + /* We have some data, deliver it */ + STbp->buffer_bytes = (blks - transfer) * + STp->block_size; + DEBC(printk(ST_DEB_MSG + "%s: ILI but enough data received %ld %d.\n", + name, count, STbp->buffer_bytes)); + if (STps->drv_block >= 0) + STps->drv_block += 1; + if (st_int_ioctl(STp, MTBSR, 1)) + return (-EIO); + } + } else if (cmdstatp->flags & SENSE_FMK) { /* FM overrides EOM */ + if (STps->eof != ST_FM_HIT) + STps->eof = ST_FM_HIT; + else + STps->eof = ST_EOD_2; + if (STp->block_size == 0) + STbp->buffer_bytes = 0; + else + STbp->buffer_bytes = + bytes - transfer * STp->block_size; + DEBC(printk(ST_DEB_MSG + "%s: EOF detected (%d bytes read).\n", + name, STbp->buffer_bytes)); + } else if (cmdstatp->flags & SENSE_EOM) { + if (STps->eof == ST_FM) + STps->eof = ST_EOD_1; + else + STps->eof = ST_EOM_OK; + if (STp->block_size == 0) + STbp->buffer_bytes = bytes - transfer; + else + STbp->buffer_bytes = + bytes - transfer * STp->block_size; + + DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n", + name, STbp->buffer_bytes)); + } + } + /* end of EOF, EOM, ILI test */ + else { /* nonzero sense key */ + DEBC(printk(ST_DEB_MSG + "%s: Tape error while reading.\n", name)); + STps->drv_block = (-1); + if (STps->eof == ST_FM && + cmdstatp->sense_hdr.sense_key == BLANK_CHECK) { + DEBC(printk(ST_DEB_MSG + "%s: Zero returned for first BLANK CHECK after EOF.\n", + name)); + STps->eof = ST_EOD_2; /* First BLANK_CHECK after FM */ + } else /* Some other extended sense code */ + retval = (-EIO); + } + + if (STbp->buffer_bytes < 0) /* Caused by bogus sense data */ + STbp->buffer_bytes = 0; + } + /* End of extended sense test */ + else { /* Non-extended sense */ + retval = STbp->syscall_result; + } + + } + /* End of error handling */ + else /* Read successful */ + STbp->buffer_bytes = bytes; + + if (STps->drv_block >= 0) { + if (STp->block_size == 0) + STps->drv_block++; + else + STps->drv_block += STbp->buffer_bytes / STp->block_size; + } + return retval; +} + + +/* Read command */ +static ssize_t +st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) +{ + ssize_t total; + ssize_t retval = 0; + ssize_t i, transfer; + int special, do_dio = 0; + struct scsi_request *SRpnt = NULL; + struct scsi_tape *STp = filp->private_data; + struct st_modedef *STm; + struct st_partstat *STps; + struct st_buffer *STbp = STp->buffer; + DEB( char *name = tape_name(STp); ) + + if (down_interruptible(&STp->lock)) + return -ERESTARTSYS; + + retval = rw_checks(STp, filp, count); + if (retval || count == 0) + goto out; + + STm = &(STp->modes[STp->current_mode]); + if (!(STm->do_read_ahead) && STp->block_size != 0 && + (count % STp->block_size) != 0) { + retval = (-EINVAL); /* Read must be integral number of blocks */ + goto out; + } + + STps = &(STp->ps[STp->partition]); + if (STps->rw == ST_WRITING) { + retval = flush_buffer(STp, 0); + if (retval) + goto out; + STps->rw = ST_READING; + } + DEB( + if (debugging && STps->eof != ST_NOEOF) + printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name, + STps->eof, STbp->buffer_bytes); + ) /* end DEB */ + + retval = setup_buffering(STp, buf, count, 1); + if (retval) + goto out; + do_dio = STbp->do_dio; + + if (STbp->buffer_bytes == 0 && + STps->eof >= ST_EOD_1) { + if (STps->eof < ST_EOD) { + STps->eof += 1; + retval = 0; + goto out; + } + retval = (-EIO); /* EOM or Blank Check */ + goto out; + } + + if (do_dio) { + /* Check the buffer writability before any tape movement. Don't alter + buffer data. */ + if (copy_from_user(&i, buf, 1) != 0 || + copy_to_user(buf, &i, 1) != 0 || + copy_from_user(&i, buf + count - 1, 1) != 0 || + copy_to_user(buf + count - 1, &i, 1) != 0) { + retval = (-EFAULT); + goto out; + } + } + + STps->rw = ST_READING; + + + /* Loop until enough data in buffer or a special condition found */ + for (total = 0, special = 0; total < count && !special;) { + + /* Get new data if the buffer is empty */ + if (STbp->buffer_bytes == 0) { + special = read_tape(STp, count - total, &SRpnt); + if (special < 0) { /* No need to continue read */ + retval = special; + goto out; + } + } + + /* Move the data from driver buffer to user buffer */ + if (STbp->buffer_bytes > 0) { + DEB( + if (debugging && STps->eof != ST_NOEOF) + printk(ST_DEB_MSG + "%s: EOF up (%d). Left %d, needed %d.\n", name, + STps->eof, STbp->buffer_bytes, + (int)(count - total)); + ) /* end DEB */ + transfer = STbp->buffer_bytes < count - total ? + STbp->buffer_bytes : count - total; + if (!do_dio) { + i = from_buffer(STbp, buf, transfer); + if (i) { + retval = i; + goto out; + } + } + buf += transfer; + total += transfer; + } + + if (STp->block_size == 0) + break; /* Read only one variable length block */ + + } /* for (total = 0, special = 0; + total < count && !special; ) */ + + /* Change the eof state if no data from tape or buffer */ + if (total == 0) { + if (STps->eof == ST_FM_HIT) { + STps->eof = ST_FM; + STps->drv_block = 0; + if (STps->drv_file >= 0) + STps->drv_file++; + } else if (STps->eof == ST_EOD_1) { + STps->eof = ST_EOD_2; + STps->drv_block = 0; + if (STps->drv_file >= 0) + STps->drv_file++; + } else if (STps->eof == ST_EOD_2) + STps->eof = ST_EOD; + } else if (STps->eof == ST_FM) + STps->eof = ST_NOEOF; + retval = total; + + out: + if (SRpnt != NULL) { + scsi_release_request(SRpnt); + SRpnt = NULL; + } + if (do_dio) { + release_buffering(STp); + STbp->buffer_bytes = 0; + } + up(&STp->lock); + + return retval; +} + + + +DEB( +/* Set the driver options */ +static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name) +{ + if (debugging) { + printk(KERN_INFO + "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n", + name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes, + STm->do_read_ahead); + printk(KERN_INFO + "%s: can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n", + name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock); + printk(KERN_INFO + "%s: defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n", + name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions, + STp->scsi2_logical); + printk(KERN_INFO + "%s: sysv: %d nowait: %d\n", name, STm->sysv, STp->immediate); + printk(KERN_INFO "%s: debugging: %d\n", + name, debugging); + } +} + ) + + +static int st_set_options(struct scsi_tape *STp, long options) +{ + int value; + long code; + struct st_modedef *STm; + char *name = tape_name(STp); + struct cdev *cd0, *cd1; + + STm = &(STp->modes[STp->current_mode]); + if (!STm->defined) { + cd0 = STm->cdevs[0]; cd1 = STm->cdevs[1]; + memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef)); + STm->cdevs[0] = cd0; STm->cdevs[1] = cd1; + modes_defined = 1; + DEBC(printk(ST_DEB_MSG + "%s: Initialized mode %d definition from mode 0\n", + name, STp->current_mode)); + } + + code = options & MT_ST_OPTIONS; + if (code == MT_ST_BOOLEANS) { + STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0; + STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0; + STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0; + STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0; + STp->two_fm = (options & MT_ST_TWO_FM) != 0; + STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0; + STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0; + STp->can_bsr = (options & MT_ST_CAN_BSR) != 0; + STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0; + if ((STp->device)->scsi_level >= SCSI_2) + STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0; + STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0; + STp->immediate = (options & MT_ST_NOWAIT) != 0; + STm->sysv = (options & MT_ST_SYSV) != 0; + DEB( debugging = (options & MT_ST_DEBUGGING) != 0; + st_log_options(STp, STm, name); ) + } else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) { + value = (code == MT_ST_SETBOOLEANS); + if ((options & MT_ST_BUFFER_WRITES) != 0) + STm->do_buffer_writes = value; + if ((options & MT_ST_ASYNC_WRITES) != 0) + STm->do_async_writes = value; + if ((options & MT_ST_DEF_WRITES) != 0) + STm->defaults_for_writes = value; + if ((options & MT_ST_READ_AHEAD) != 0) + STm->do_read_ahead = value; + if ((options & MT_ST_TWO_FM) != 0) + STp->two_fm = value; + if ((options & MT_ST_FAST_MTEOM) != 0) + STp->fast_mteom = value; + if ((options & MT_ST_AUTO_LOCK) != 0) + STp->do_auto_lock = value; + if ((options & MT_ST_CAN_BSR) != 0) + STp->can_bsr = value; + if ((options & MT_ST_NO_BLKLIMS) != 0) + STp->omit_blklims = value; + if ((STp->device)->scsi_level >= SCSI_2 && + (options & MT_ST_CAN_PARTITIONS) != 0) + STp->can_partitions = value; + if ((options & MT_ST_SCSI2LOGICAL) != 0) + STp->scsi2_logical = value; + if ((options & MT_ST_NOWAIT) != 0) + STp->immediate = value; + if ((options & MT_ST_SYSV) != 0) + STm->sysv = value; + DEB( + if ((options & MT_ST_DEBUGGING) != 0) + debugging = value; + st_log_options(STp, STm, name); ) + } else if (code == MT_ST_WRITE_THRESHOLD) { + /* Retained for compatibility */ + } else if (code == MT_ST_DEF_BLKSIZE) { + value = (options & ~MT_ST_OPTIONS); + if (value == ~MT_ST_OPTIONS) { + STm->default_blksize = (-1); + DEBC( printk(KERN_INFO "%s: Default block size disabled.\n", name)); + } else { + STm->default_blksize = value; + DEBC( printk(KERN_INFO "%s: Default block size set to %d bytes.\n", + name, STm->default_blksize)); + if (STp->ready == ST_READY) { + STp->blksize_changed = 0; + set_mode_densblk(STp, STm); + } + } + } else if (code == MT_ST_TIMEOUTS) { + value = (options & ~MT_ST_OPTIONS); + if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) { + STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ; + DEBC( printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name, + (value & ~MT_ST_SET_LONG_TIMEOUT))); + } else { + STp->device->timeout = value * HZ; + DEBC( printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n", + name, value) ); + } + } else if (code == MT_ST_SET_CLN) { + value = (options & ~MT_ST_OPTIONS) & 0xff; + if (value != 0 && + value < EXTENDED_SENSE_START && value >= SCSI_SENSE_BUFFERSIZE) + return (-EINVAL); + STp->cln_mode = value; + STp->cln_sense_mask = (options >> 8) & 0xff; + STp->cln_sense_value = (options >> 16) & 0xff; + printk(KERN_INFO + "%s: Cleaning request mode %d, mask %02x, value %02x\n", + name, value, STp->cln_sense_mask, STp->cln_sense_value); + } else if (code == MT_ST_DEF_OPTIONS) { + code = (options & ~MT_ST_CLEAR_DEFAULT); + value = (options & MT_ST_CLEAR_DEFAULT); + if (code == MT_ST_DEF_DENSITY) { + if (value == MT_ST_CLEAR_DEFAULT) { + STm->default_density = (-1); + DEBC( printk(KERN_INFO "%s: Density default disabled.\n", + name)); + } else { + STm->default_density = value & 0xff; + DEBC( printk(KERN_INFO "%s: Density default set to %x\n", + name, STm->default_density)); + if (STp->ready == ST_READY) { + STp->density_changed = 0; + set_mode_densblk(STp, STm); + } + } + } else if (code == MT_ST_DEF_DRVBUFFER) { + if (value == MT_ST_CLEAR_DEFAULT) { + STp->default_drvbuffer = 0xff; + DEBC( printk(KERN_INFO + "%s: Drive buffer default disabled.\n", name)); + } else { + STp->default_drvbuffer = value & 7; + DEBC( printk(KERN_INFO + "%s: Drive buffer default set to %x\n", + name, STp->default_drvbuffer)); + if (STp->ready == ST_READY) + st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer); + } + } else if (code == MT_ST_DEF_COMPRESSION) { + if (value == MT_ST_CLEAR_DEFAULT) { + STm->default_compression = ST_DONT_TOUCH; + DEBC( printk(KERN_INFO + "%s: Compression default disabled.\n", name)); + } else { + if ((value & 0xff00) != 0) { + STp->c_algo = (value & 0xff00) >> 8; + DEBC( printk(KERN_INFO "%s: Compression algorithm set to 0x%x.\n", + name, STp->c_algo)); + } + if ((value & 0xff) != 0xff) { + STm->default_compression = (value & 1 ? ST_YES : ST_NO); + DEBC( printk(KERN_INFO "%s: Compression default set to %x\n", + name, (value & 1))); + if (STp->ready == ST_READY) { + STp->compression_changed = 0; + st_compression(STp, (STm->default_compression == ST_YES)); + } + } + } + } + } else + return (-EIO); + + return 0; +} + +#define MODE_HEADER_LENGTH 4 + +/* Mode header and page byte offsets */ +#define MH_OFF_DATA_LENGTH 0 +#define MH_OFF_MEDIUM_TYPE 1 +#define MH_OFF_DEV_SPECIFIC 2 +#define MH_OFF_BDESCS_LENGTH 3 +#define MP_OFF_PAGE_NBR 0 +#define MP_OFF_PAGE_LENGTH 1 + +/* Mode header and page bit masks */ +#define MH_BIT_WP 0x80 +#define MP_MSK_PAGE_NBR 0x3f + +/* Don't return block descriptors */ +#define MODE_SENSE_OMIT_BDESCS 0x08 + +#define MODE_SELECT_PAGE_FORMAT 0x10 + +/* Read a mode page into the tape buffer. The block descriptors are included + if incl_block_descs is true. The page control is ored to the page number + parameter, if necessary. */ +static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs) +{ + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt = NULL; + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = MODE_SENSE; + if (omit_block_descs) + cmd[1] = MODE_SENSE_OMIT_BDESCS; + cmd[2] = page; + cmd[4] = 255; + + SRpnt = st_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_FROM_DEVICE, + STp->device->timeout, 0, 1); + if (SRpnt == NULL) + return (STp->buffer)->syscall_result; + + scsi_release_request(SRpnt); + + return (STp->buffer)->syscall_result; +} + + +/* Send the mode page in the tape buffer to the drive. Assumes that the mode data + in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */ +static int write_mode_page(struct scsi_tape *STp, int page, int slow) +{ + int pgo; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt = NULL; + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = MODE_SELECT; + cmd[1] = MODE_SELECT_PAGE_FORMAT; + pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH]; + cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2; + + /* Clear reserved fields */ + (STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0; + (STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0; + (STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP; + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR; + + SRpnt = st_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_TO_DEVICE, + (slow ? STp->long_timeout : STp->device->timeout), 0, 1); + if (SRpnt == NULL) + return (STp->buffer)->syscall_result; + + scsi_release_request(SRpnt); + + return (STp->buffer)->syscall_result; +} + + +#define COMPRESSION_PAGE 0x0f +#define COMPRESSION_PAGE_LENGTH 16 + +#define CP_OFF_DCE_DCC 2 +#define CP_OFF_C_ALGO 7 + +#define DCE_MASK 0x80 +#define DCC_MASK 0x40 +#define RED_MASK 0x60 + + +/* Control the compression with mode page 15. Algorithm not changed if zero. + + The block descriptors are read and written because Sony SDT-7000 does not + work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>). + Including block descriptors should not cause any harm to other drives. */ + +static int st_compression(struct scsi_tape * STp, int state) +{ + int retval; + int mpoffs; /* Offset to mode page start */ + unsigned char *b_data = (STp->buffer)->b_data; + DEB( char *name = tape_name(STp); ) + + if (STp->ready != ST_READY) + return (-EIO); + + /* Read the current page contents */ + retval = read_mode_page(STp, COMPRESSION_PAGE, 0); + if (retval) { + DEBC(printk(ST_DEB_MSG "%s: Compression mode page not supported.\n", + name)); + return (-EIO); + } + + mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH]; + DEBC(printk(ST_DEB_MSG "%s: Compression state is %d.\n", name, + (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0))); + + /* Check if compression can be changed */ + if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) { + DEBC(printk(ST_DEB_MSG "%s: Compression not supported.\n", name)); + return (-EIO); + } + + /* Do the change */ + if (state) { + b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK; + if (STp->c_algo != 0) + b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo; + } + else { + b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK; + if (STp->c_algo != 0) + b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */ + } + + retval = write_mode_page(STp, COMPRESSION_PAGE, 0); + if (retval) { + DEBC(printk(ST_DEB_MSG "%s: Compression change failed.\n", name)); + return (-EIO); + } + DEBC(printk(ST_DEB_MSG "%s: Compression state changed to %d.\n", + name, state)); + + STp->compression_changed = 1; + return 0; +} + + +/* Process the load and unload commands (does unload if the load code is zero) */ +static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code) +{ + int retval = (-EIO), timeout; + DEB( char *name = tape_name(STp); ) + unsigned char cmd[MAX_COMMAND_SIZE]; + struct st_partstat *STps; + struct scsi_request *SRpnt; + + if (STp->ready != ST_READY && !load_code) { + if (STp->ready == ST_NO_TAPE) + return (-ENOMEDIUM); + else + return (-EIO); + } + + memset(cmd, 0, MAX_COMMAND_SIZE); + cmd[0] = START_STOP; + if (load_code) + cmd[4] |= 1; + /* + * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A + */ + if (load_code >= 1 + MT_ST_HPLOADER_OFFSET + && load_code <= 6 + MT_ST_HPLOADER_OFFSET) { + DEBC(printk(ST_DEB_MSG "%s: Enhanced %sload slot %2d.\n", + name, (cmd[4]) ? "" : "un", + load_code - MT_ST_HPLOADER_OFFSET)); + cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */ + } + if (STp->immediate) { + cmd[1] = 1; /* Don't wait for completion */ + timeout = STp->device->timeout; + } + else + timeout = STp->long_timeout; + + DEBC( + if (!load_code) + printk(ST_DEB_MSG "%s: Unloading tape.\n", name); + else + printk(ST_DEB_MSG "%s: Loading tape.\n", name); + ); + + SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE, + timeout, MAX_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + retval = (STp->buffer)->syscall_result; + scsi_release_request(SRpnt); + + if (!retval) { /* SCSI command successful */ + + if (!load_code) { + STp->rew_at_close = 0; + STp->ready = ST_NO_TAPE; + } + else { + STp->rew_at_close = STp->autorew_dev; + retval = check_tape(STp, filp); + if (retval > 0) + retval = 0; + } + } + else { + STps = &(STp->ps[STp->partition]); + STps->drv_file = STps->drv_block = (-1); + } + + return retval; +} + +#if DEBUG +#define ST_DEB_FORWARD 0 +#define ST_DEB_BACKWARD 1 +static void deb_space_print(char *name, int direction, char *units, unsigned char *cmd) +{ + s32 sc; + + sc = cmd[2] & 0x80 ? 0xff000000 : 0; + sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4]; + if (direction) + sc = -sc; + printk(ST_DEB_MSG "%s: Spacing tape %s over %d %s.\n", name, + direction ? "backward" : "forward", sc, units); +} +#endif + + +/* Internal ioctl function */ +static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg) +{ + int timeout; + long ltmp; + int ioctl_result; + int chg_eof = 1; + unsigned char cmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + struct st_partstat *STps; + int fileno, blkno, at_sm, undone; + int datalen = 0, direction = DMA_NONE; + char *name = tape_name(STp); + + WARN_ON(STp->buffer->do_dio != 0); + if (STp->ready != ST_READY) { + if (STp->ready == ST_NO_TAPE) + return (-ENOMEDIUM); + else + return (-EIO); + } + timeout = STp->long_timeout; + STps = &(STp->ps[STp->partition]); + fileno = STps->drv_file; + blkno = STps->drv_block; + at_sm = STps->at_sm; + + memset(cmd, 0, MAX_COMMAND_SIZE); + switch (cmd_in) { + case MTFSFM: + chg_eof = 0; /* Changed from the FSF after this */ + case MTFSF: + cmd[0] = SPACE; + cmd[1] = 0x01; /* Space FileMarks */ + cmd[2] = (arg >> 16); + cmd[3] = (arg >> 8); + cmd[4] = arg; + DEBC(deb_space_print(name, ST_DEB_FORWARD, "filemarks", cmd);) + if (fileno >= 0) + fileno += arg; + blkno = 0; + at_sm &= (arg == 0); + break; + case MTBSFM: + chg_eof = 0; /* Changed from the FSF after this */ + case MTBSF: + cmd[0] = SPACE; + cmd[1] = 0x01; /* Space FileMarks */ + ltmp = (-arg); + cmd[2] = (ltmp >> 16); + cmd[3] = (ltmp >> 8); + cmd[4] = ltmp; + DEBC(deb_space_print(name, ST_DEB_BACKWARD, "filemarks", cmd);) + if (fileno >= 0) + fileno -= arg; + blkno = (-1); /* We can't know the block number */ + at_sm &= (arg == 0); + break; + case MTFSR: + cmd[0] = SPACE; + cmd[1] = 0x00; /* Space Blocks */ + cmd[2] = (arg >> 16); + cmd[3] = (arg >> 8); + cmd[4] = arg; + DEBC(deb_space_print(name, ST_DEB_FORWARD, "blocks", cmd);) + if (blkno >= 0) + blkno += arg; + at_sm &= (arg == 0); + break; + case MTBSR: + cmd[0] = SPACE; + cmd[1] = 0x00; /* Space Blocks */ + ltmp = (-arg); + cmd[2] = (ltmp >> 16); + cmd[3] = (ltmp >> 8); + cmd[4] = ltmp; + DEBC(deb_space_print(name, ST_DEB_BACKWARD, "blocks", cmd);) + if (blkno >= 0) + blkno -= arg; + at_sm &= (arg == 0); + break; + case MTFSS: + cmd[0] = SPACE; + cmd[1] = 0x04; /* Space Setmarks */ + cmd[2] = (arg >> 16); + cmd[3] = (arg >> 8); + cmd[4] = arg; + DEBC(deb_space_print(name, ST_DEB_FORWARD, "setmarks", cmd);) + if (arg != 0) { + blkno = fileno = (-1); + at_sm = 1; + } + break; + case MTBSS: + cmd[0] = SPACE; + cmd[1] = 0x04; /* Space Setmarks */ + ltmp = (-arg); + cmd[2] = (ltmp >> 16); + cmd[3] = (ltmp >> 8); + cmd[4] = ltmp; + DEBC(deb_space_print(name, ST_DEB_BACKWARD, "setmarks", cmd);) + if (arg != 0) { + blkno = fileno = (-1); + at_sm = 1; + } + break; + case MTWEOF: + case MTWSM: + if (STp->write_prot) + return (-EACCES); + cmd[0] = WRITE_FILEMARKS; + if (cmd_in == MTWSM) + cmd[1] = 2; + cmd[2] = (arg >> 16); + cmd[3] = (arg >> 8); + cmd[4] = arg; + timeout = STp->device->timeout; + DEBC( + if (cmd_in == MTWEOF) + printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name, + cmd[2] * 65536 + cmd[3] * 256 + cmd[4]); + else + printk(ST_DEB_MSG "%s: Writing %d setmarks.\n", name, + cmd[2] * 65536 + cmd[3] * 256 + cmd[4]); + ) + if (fileno >= 0) + fileno += arg; + blkno = 0; + at_sm = (cmd_in == MTWSM); + break; + case MTREW: + cmd[0] = REZERO_UNIT; + if (STp->immediate) { + cmd[1] = 1; /* Don't wait for completion */ + timeout = STp->device->timeout; + } + DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name)); + fileno = blkno = at_sm = 0; + break; + case MTNOP: + DEBC(printk(ST_DEB_MSG "%s: No op on tape.\n", name)); + return 0; /* Should do something ? */ + break; + case MTRETEN: + cmd[0] = START_STOP; + if (STp->immediate) { + cmd[1] = 1; /* Don't wait for completion */ + timeout = STp->device->timeout; + } + cmd[4] = 3; + DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name)); + fileno = blkno = at_sm = 0; + break; + case MTEOM: + if (!STp->fast_mteom) { + /* space to the end of tape */ + ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff); + fileno = STps->drv_file; + if (STps->eof >= ST_EOD_1) + return 0; + /* The next lines would hide the number of spaced FileMarks + That's why I inserted the previous lines. I had no luck + with detecting EOM with FSF, so we go now to EOM. + Joerg Weule */ + } else + fileno = (-1); + cmd[0] = SPACE; + cmd[1] = 3; + DEBC(printk(ST_DEB_MSG "%s: Spacing to end of recorded medium.\n", + name)); + blkno = -1; + at_sm = 0; + break; + case MTERASE: + if (STp->write_prot) + return (-EACCES); + cmd[0] = ERASE; + cmd[1] = (arg ? 1 : 0); /* Long erase with non-zero argument */ + if (STp->immediate) { + cmd[1] |= 2; /* Don't wait for completion */ + timeout = STp->device->timeout; + } + else + timeout = STp->long_timeout * 8; + + DEBC(printk(ST_DEB_MSG "%s: Erasing tape.\n", name)); + fileno = blkno = at_sm = 0; + break; + case MTSETBLK: /* Set block length */ + case MTSETDENSITY: /* Set tape density */ + case MTSETDRVBUFFER: /* Set drive buffering */ + case SET_DENS_AND_BLK: /* Set density and block size */ + chg_eof = 0; + if (STp->dirty || (STp->buffer)->buffer_bytes != 0) + return (-EIO); /* Not allowed if data in buffer */ + if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) && + (arg & MT_ST_BLKSIZE_MASK) != 0 && + STp->max_block > 0 && + ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block || + (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) { + printk(KERN_WARNING "%s: Illegal block size.\n", name); + return (-EINVAL); + } + cmd[0] = MODE_SELECT; + if ((STp->use_pf & USE_PF)) + cmd[1] = MODE_SELECT_PAGE_FORMAT; + cmd[4] = datalen = 12; + direction = DMA_TO_DEVICE; + + memset((STp->buffer)->b_data, 0, 12); + if (cmd_in == MTSETDRVBUFFER) + (STp->buffer)->b_data[2] = (arg & 7) << 4; + else + (STp->buffer)->b_data[2] = + STp->drv_buffer << 4; + (STp->buffer)->b_data[3] = 8; /* block descriptor length */ + if (cmd_in == MTSETDENSITY) { + (STp->buffer)->b_data[4] = arg; + STp->density_changed = 1; /* At least we tried ;-) */ + } else if (cmd_in == SET_DENS_AND_BLK) + (STp->buffer)->b_data[4] = arg >> 24; + else + (STp->buffer)->b_data[4] = STp->density; + if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) { + ltmp = arg & MT_ST_BLKSIZE_MASK; + if (cmd_in == MTSETBLK) + STp->blksize_changed = 1; /* At least we tried ;-) */ + } else + ltmp = STp->block_size; + (STp->buffer)->b_data[9] = (ltmp >> 16); + (STp->buffer)->b_data[10] = (ltmp >> 8); + (STp->buffer)->b_data[11] = ltmp; + timeout = STp->device->timeout; + DEBC( + if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) + printk(ST_DEB_MSG + "%s: Setting block size to %d bytes.\n", name, + (STp->buffer)->b_data[9] * 65536 + + (STp->buffer)->b_data[10] * 256 + + (STp->buffer)->b_data[11]); + if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK) + printk(ST_DEB_MSG + "%s: Setting density code to %x.\n", name, + (STp->buffer)->b_data[4]); + if (cmd_in == MTSETDRVBUFFER) + printk(ST_DEB_MSG + "%s: Setting drive buffer code to %d.\n", name, + ((STp->buffer)->b_data[2] >> 4) & 7); + ) + break; + default: + return (-ENOSYS); + } + + SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction, + timeout, MAX_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + ioctl_result = (STp->buffer)->syscall_result; + + if (!ioctl_result) { /* SCSI command successful */ + scsi_release_request(SRpnt); + SRpnt = NULL; + STps->drv_block = blkno; + STps->drv_file = fileno; + STps->at_sm = at_sm; + + if (cmd_in == MTBSFM) + ioctl_result = st_int_ioctl(STp, MTFSF, 1); + else if (cmd_in == MTFSFM) + ioctl_result = st_int_ioctl(STp, MTBSF, 1); + + if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) { + int old_block_size = STp->block_size; + STp->block_size = arg & MT_ST_BLKSIZE_MASK; + if (STp->block_size != 0) { + if (old_block_size == 0) + normalize_buffer(STp->buffer); + (STp->buffer)->buffer_blocks = + (STp->buffer)->buffer_size / STp->block_size; + } + (STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0; + if (cmd_in == SET_DENS_AND_BLK) + STp->density = arg >> MT_ST_DENSITY_SHIFT; + } else if (cmd_in == MTSETDRVBUFFER) + STp->drv_buffer = (arg & 7); + else if (cmd_in == MTSETDENSITY) + STp->density = arg; + + if (cmd_in == MTEOM) + STps->eof = ST_EOD; + else if (cmd_in == MTFSF) + STps->eof = ST_FM; + else if (chg_eof) + STps->eof = ST_NOEOF; + + if (cmd_in == MTWEOF) + STps->rw = ST_IDLE; + } else { /* SCSI command was not completely successful. Don't return + from this block without releasing the SCSI command block! */ + struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat; + + if (cmdstatp->flags & SENSE_EOM) { + if (cmd_in != MTBSF && cmd_in != MTBSFM && + cmd_in != MTBSR && cmd_in != MTBSS) + STps->eof = ST_EOM_OK; + STps->drv_block = 0; + } + + if (cmdstatp->remainder_valid) + undone = (int)cmdstatp->uremainder64; + else + undone = 0; + + if (cmd_in == MTWEOF && + cmdstatp->have_sense && + (cmdstatp->flags & SENSE_EOM) && + (cmdstatp->sense_hdr.sense_key == NO_SENSE || + cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) && + undone == 0) { + ioctl_result = 0; /* EOF written succesfully at EOM */ + if (fileno >= 0) + fileno++; + STps->drv_file = fileno; + STps->eof = ST_NOEOF; + } else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) { + if (fileno >= 0) + STps->drv_file = fileno - undone; + else + STps->drv_file = fileno; + STps->drv_block = -1; + STps->eof = ST_NOEOF; + } else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) { + if (arg > 0 && undone < 0) /* Some drives get this wrong */ + undone = (-undone); + if (STps->drv_file >= 0) + STps->drv_file = fileno + undone; + STps->drv_block = 0; + STps->eof = ST_NOEOF; + } else if (cmd_in == MTFSR) { + if (cmdstatp->flags & SENSE_FMK) { /* Hit filemark */ + if (STps->drv_file >= 0) + STps->drv_file++; + STps->drv_block = 0; + STps->eof = ST_FM; + } else { + if (blkno >= undone) + STps->drv_block = blkno - undone; + else + STps->drv_block = (-1); + STps->eof = ST_NOEOF; + } + } else if (cmd_in == MTBSR) { + if (cmdstatp->flags & SENSE_FMK) { /* Hit filemark */ + STps->drv_file--; + STps->drv_block = (-1); + } else { + if (arg > 0 && undone < 0) /* Some drives get this wrong */ + undone = (-undone); + if (STps->drv_block >= 0) + STps->drv_block = blkno + undone; + } + STps->eof = ST_NOEOF; + } else if (cmd_in == MTEOM) { + STps->drv_file = (-1); + STps->drv_block = (-1); + STps->eof = ST_EOD; + } else if (cmd_in == MTSETBLK || + cmd_in == MTSETDENSITY || + cmd_in == MTSETDRVBUFFER || + cmd_in == SET_DENS_AND_BLK) { + if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST && + !(STp->use_pf & PF_TESTED)) { + /* Try the other possible state of Page Format if not + already tried */ + STp->use_pf = !STp->use_pf | PF_TESTED; + scsi_release_request(SRpnt); + SRpnt = NULL; + return st_int_ioctl(STp, cmd_in, arg); + } + } else if (chg_eof) + STps->eof = ST_NOEOF; + + if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK) + STps->eof = ST_EOD; + + scsi_release_request(SRpnt); + SRpnt = NULL; + } + + return ioctl_result; +} + + +/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc + structure. */ + +static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition, + int logical) +{ + int result; + unsigned char scmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + DEB( char *name = tape_name(STp); ) + + if (STp->ready != ST_READY) + return (-EIO); + + memset(scmd, 0, MAX_COMMAND_SIZE); + if ((STp->device)->scsi_level < SCSI_2) { + scmd[0] = QFA_REQUEST_BLOCK; + scmd[4] = 3; + } else { + scmd[0] = READ_POSITION; + if (!logical && !STp->scsi2_logical) + scmd[1] = 1; + } + SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE, + STp->device->timeout, MAX_READY_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + if ((STp->buffer)->syscall_result != 0 || + (STp->device->scsi_level >= SCSI_2 && + ((STp->buffer)->b_data[0] & 4) != 0)) { + *block = *partition = 0; + DEBC(printk(ST_DEB_MSG "%s: Can't read tape position.\n", name)); + result = (-EIO); + } else { + result = 0; + if ((STp->device)->scsi_level < SCSI_2) { + *block = ((STp->buffer)->b_data[0] << 16) + + ((STp->buffer)->b_data[1] << 8) + + (STp->buffer)->b_data[2]; + *partition = 0; + } else { + *block = ((STp->buffer)->b_data[4] << 24) + + ((STp->buffer)->b_data[5] << 16) + + ((STp->buffer)->b_data[6] << 8) + + (STp->buffer)->b_data[7]; + *partition = (STp->buffer)->b_data[1]; + if (((STp->buffer)->b_data[0] & 0x80) && + (STp->buffer)->b_data[1] == 0) /* BOP of partition 0 */ + STp->ps[0].drv_block = STp->ps[0].drv_file = 0; + } + DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name, + *block, *partition)); + } + scsi_release_request(SRpnt); + SRpnt = NULL; + + return result; +} + + +/* Set the tape block and partition. Negative partition means that only the + block should be set in vendor specific way. */ +static int set_location(struct scsi_tape *STp, unsigned int block, int partition, + int logical) +{ + struct st_partstat *STps; + int result, p; + unsigned int blk; + int timeout; + unsigned char scmd[MAX_COMMAND_SIZE]; + struct scsi_request *SRpnt; + DEB( char *name = tape_name(STp); ) + + if (STp->ready != ST_READY) + return (-EIO); + timeout = STp->long_timeout; + STps = &(STp->ps[STp->partition]); + + DEBC(printk(ST_DEB_MSG "%s: Setting block to %d and partition to %d.\n", + name, block, partition)); + DEB(if (partition < 0) + return (-EIO); ) + + /* Update the location at the partition we are leaving */ + if ((!STp->can_partitions && partition != 0) || + partition >= ST_NBR_PARTITIONS) + return (-EINVAL); + if (partition != STp->partition) { + if (get_location(STp, &blk, &p, 1)) + STps->last_block_valid = 0; + else { + STps->last_block_valid = 1; + STps->last_block_visited = blk; + DEBC(printk(ST_DEB_MSG + "%s: Visited block %d for partition %d saved.\n", + name, blk, STp->partition)); + } + } + + memset(scmd, 0, MAX_COMMAND_SIZE); + if ((STp->device)->scsi_level < SCSI_2) { + scmd[0] = QFA_SEEK_BLOCK; + scmd[2] = (block >> 16); + scmd[3] = (block >> 8); + scmd[4] = block; + scmd[5] = 0; + } else { + scmd[0] = SEEK_10; + scmd[3] = (block >> 24); + scmd[4] = (block >> 16); + scmd[5] = (block >> 8); + scmd[6] = block; + if (!logical && !STp->scsi2_logical) + scmd[1] = 4; + if (STp->partition != partition) { + scmd[1] |= 2; + scmd[8] = partition; + DEBC(printk(ST_DEB_MSG + "%s: Trying to change partition from %d to %d\n", + name, STp->partition, partition)); + } + } + if (STp->immediate) { + scmd[1] |= 1; /* Don't wait for completion */ + timeout = STp->device->timeout; + } + + SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE, + timeout, MAX_READY_RETRIES, 1); + if (!SRpnt) + return (STp->buffer)->syscall_result; + + STps->drv_block = STps->drv_file = (-1); + STps->eof = ST_NOEOF; + if ((STp->buffer)->syscall_result != 0) { + result = (-EIO); + if (STp->can_partitions && + (STp->device)->scsi_level >= SCSI_2 && + (p = find_partition(STp)) >= 0) + STp->partition = p; + } else { + if (STp->can_partitions) { + STp->partition = partition; + STps = &(STp->ps[partition]); + if (!STps->last_block_valid || + STps->last_block_visited != block) { + STps->at_sm = 0; + STps->rw = ST_IDLE; + } + } else + STps->at_sm = 0; + if (block == 0) + STps->drv_block = STps->drv_file = 0; + result = 0; + } + + scsi_release_request(SRpnt); + SRpnt = NULL; + + return result; +} + + +/* Find the current partition number for the drive status. Called from open and + returns either partition number of negative error code. */ +static int find_partition(struct scsi_tape *STp) +{ + int i, partition; + unsigned int block; + + if ((i = get_location(STp, &block, &partition, 1)) < 0) + return i; + if (partition >= ST_NBR_PARTITIONS) + return (-EIO); + return partition; +} + + +/* Change the partition if necessary */ +static int switch_partition(struct scsi_tape *STp) +{ + struct st_partstat *STps; + + if (STp->partition == STp->new_partition) + return 0; + STps = &(STp->ps[STp->new_partition]); + if (!STps->last_block_valid) + STps->last_block_visited = 0; + return set_location(STp, STps->last_block_visited, STp->new_partition, 1); +} + +/* Functions for reading and writing the medium partition mode page. */ + +#define PART_PAGE 0x11 +#define PART_PAGE_FIXED_LENGTH 8 + +#define PP_OFF_MAX_ADD_PARTS 2 +#define PP_OFF_NBR_ADD_PARTS 3 +#define PP_OFF_FLAGS 4 +#define PP_OFF_PART_UNITS 6 +#define PP_OFF_RESERVED 7 + +#define PP_BIT_IDP 0x20 +#define PP_MSK_PSUM_MB 0x10 + +/* Get the number of partitions on the tape. As a side effect reads the + mode page into the tape buffer. */ +static int nbr_partitions(struct scsi_tape *STp) +{ + int result; + DEB( char *name = tape_name(STp); ) + + if (STp->ready != ST_READY) + return (-EIO); + + result = read_mode_page(STp, PART_PAGE, 1); + + if (result) { + DEBC(printk(ST_DEB_MSG "%s: Can't read medium partition page.\n", + name)); + result = (-EIO); + } else { + result = (STp->buffer)->b_data[MODE_HEADER_LENGTH + + PP_OFF_NBR_ADD_PARTS] + 1; + DEBC(printk(ST_DEB_MSG "%s: Number of partitions %d.\n", name, result)); + } + + return result; +} + + +/* Partition the tape into two partitions if size > 0 or one partition if + size == 0. + + The block descriptors are read and written because Sony SDT-7000 does not + work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>). + + My HP C1533A drive returns only one partition size field. This is used to + set the size of partition 1. There is no size field for the default partition. + Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is + used to set the size of partition 1 (this is what the SCSI-3 standard specifies). + The following algorithm is used to accommodate both drives: if the number of + partition size fields is greater than the maximum number of additional partitions + in the mode page, the second field is used. Otherwise the first field is used. + + For Seagate DDS drives the page length must be 8 when no partitions is defined + and 10 when 1 partition is defined (information from Eric Lee Green). This is + is acceptable also to some other old drives and enforced if the first partition + size field is used for the first additional partition size. + */ +static int partition_tape(struct scsi_tape *STp, int size) +{ + char *name = tape_name(STp); + int result; + int pgo, psd_cnt, psdo; + unsigned char *bp; + + result = read_mode_page(STp, PART_PAGE, 0); + if (result) { + DEBC(printk(ST_DEB_MSG "%s: Can't read partition mode page.\n", name)); + return result; + } + /* The mode page is in the buffer. Let's modify it and write it. */ + bp = (STp->buffer)->b_data; + pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH]; + DEBC(printk(ST_DEB_MSG "%s: Partition page length is %d bytes.\n", + name, bp[pgo + MP_OFF_PAGE_LENGTH] + 2)); + + psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2; + psdo = pgo + PART_PAGE_FIXED_LENGTH; + if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) { + bp[psdo] = bp[psdo + 1] = 0xff; /* Rest of the tape */ + psdo += 2; + } + memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2); + + DEBC(printk("%s: psd_cnt %d, max.parts %d, nbr_parts %d\n", name, + psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS], + bp[pgo + PP_OFF_NBR_ADD_PARTS])); + + if (size <= 0) { + bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0; + if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS]) + bp[pgo + MP_OFF_PAGE_LENGTH] = 6; + DEBC(printk(ST_DEB_MSG "%s: Formatting tape with one partition.\n", + name)); + } else { + bp[psdo] = (size >> 8) & 0xff; + bp[psdo + 1] = size & 0xff; + bp[pgo + 3] = 1; + if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8) + bp[pgo + MP_OFF_PAGE_LENGTH] = 8; + DEBC(printk(ST_DEB_MSG + "%s: Formatting tape with two partitions (1 = %d MB).\n", + name, size)); + } + bp[pgo + PP_OFF_PART_UNITS] = 0; + bp[pgo + PP_OFF_RESERVED] = 0; + bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB; + + result = write_mode_page(STp, PART_PAGE, 1); + if (result) { + printk(KERN_INFO "%s: Partitioning of tape failed.\n", name); + result = (-EIO); + } + + return result; +} + + + +/* The ioctl command */ +static int st_ioctl(struct inode *inode, struct file *file, + unsigned int cmd_in, unsigned long arg) +{ + int i, cmd_nr, cmd_type, bt; + int retval = 0; + unsigned int blk; + struct scsi_tape *STp = file->private_data; + struct st_modedef *STm; + struct st_partstat *STps; + char *name = tape_name(STp); + void __user *p = (void __user *)arg; + + if (down_interruptible(&STp->lock)) + return -ERESTARTSYS; + + DEB( + if (debugging && !STp->in_use) { + printk(ST_DEB_MSG "%s: Incorrect device.\n", name); + retval = (-EIO); + goto out; + } ) /* end DEB */ + + STm = &(STp->modes[STp->current_mode]); + STps = &(STp->ps[STp->partition]); + + /* + * If we are in the middle of error recovery, don't let anyone + * else try and use this device. Also, if error recovery fails, it + * may try and take the device offline, in which case all further + * access to the device is prohibited. + */ + retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p, file); + if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV) + goto out; + retval = 0; + + cmd_type = _IOC_TYPE(cmd_in); + cmd_nr = _IOC_NR(cmd_in); + + if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) { + struct mtop mtc; + + if (_IOC_SIZE(cmd_in) != sizeof(mtc)) { + retval = (-EINVAL); + goto out; + } + + i = copy_from_user(&mtc, p, sizeof(struct mtop)); + if (i) { + retval = (-EFAULT); + goto out; + } + + if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) { + printk(KERN_WARNING + "%s: MTSETDRVBUFFER only allowed for root.\n", name); + retval = (-EPERM); + goto out; + } + if (!STm->defined && + (mtc.mt_op != MTSETDRVBUFFER && + (mtc.mt_count & MT_ST_OPTIONS) == 0)) { + retval = (-ENXIO); + goto out; + } + + if (!STp->pos_unknown) { + + if (STps->eof == ST_FM_HIT) { + if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM || + mtc.mt_op == MTEOM) { + mtc.mt_count -= 1; + if (STps->drv_file >= 0) + STps->drv_file += 1; + } else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) { + mtc.mt_count += 1; + if (STps->drv_file >= 0) + STps->drv_file += 1; + } + } + + if (mtc.mt_op == MTSEEK) { + /* Old position must be restored if partition will be + changed */ + i = !STp->can_partitions || + (STp->new_partition != STp->partition); + } else { + i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL || + mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM || + mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD || + mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM || + mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM || + mtc.mt_op == MTCOMPRESSION; + } + i = flush_buffer(STp, i); + if (i < 0) { + retval = i; + goto out; + } + if (STps->rw == ST_WRITING && + (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL || + mtc.mt_op == MTSEEK || + mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) { + i = st_int_ioctl(STp, MTWEOF, 1); + if (i < 0) { + retval = i; + goto out; + } + if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) + mtc.mt_count++; + STps->rw = ST_IDLE; + } + + } else { + /* + * If there was a bus reset, block further access + * to this device. If the user wants to rewind the tape, + * then reset the flag and allow access again. + */ + if (mtc.mt_op != MTREW && + mtc.mt_op != MTOFFL && + mtc.mt_op != MTRETEN && + mtc.mt_op != MTERASE && + mtc.mt_op != MTSEEK && + mtc.mt_op != MTEOM) { + retval = (-EIO); + goto out; + } + reset_state(STp); + /* remove this when the midlevel properly clears was_reset */ + STp->device->was_reset = 0; + } + + if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK && + mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM && + mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART) + STps->rw = ST_IDLE; /* Prevent automatic WEOF and fsf */ + + if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED) + do_door_lock(STp, 0); /* Ignore result! */ + + if (mtc.mt_op == MTSETDRVBUFFER && + (mtc.mt_count & MT_ST_OPTIONS) != 0) { + retval = st_set_options(STp, mtc.mt_count); + goto out; + } + + if (mtc.mt_op == MTSETPART) { + if (!STp->can_partitions || + mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) { + retval = (-EINVAL); + goto out; + } + if (mtc.mt_count >= STp->nbr_partitions && + (STp->nbr_partitions = nbr_partitions(STp)) < 0) { + retval = (-EIO); + goto out; + } + if (mtc.mt_count >= STp->nbr_partitions) { + retval = (-EINVAL); + goto out; + } + STp->new_partition = mtc.mt_count; + retval = 0; + goto out; + } + + if (mtc.mt_op == MTMKPART) { + if (!STp->can_partitions) { + retval = (-EINVAL); + goto out; + } + if ((i = st_int_ioctl(STp, MTREW, 0)) < 0 || + (i = partition_tape(STp, mtc.mt_count)) < 0) { + retval = i; + goto out; + } + for (i = 0; i < ST_NBR_PARTITIONS; i++) { + STp->ps[i].rw = ST_IDLE; + STp->ps[i].at_sm = 0; + STp->ps[i].last_block_valid = 0; + } + STp->partition = STp->new_partition = 0; + STp->nbr_partitions = 1; /* Bad guess ?-) */ + STps->drv_block = STps->drv_file = 0; + retval = 0; + goto out; + } + + if (mtc.mt_op == MTSEEK) { + i = set_location(STp, mtc.mt_count, STp->new_partition, 0); + if (!STp->can_partitions) + STp->ps[0].rw = ST_IDLE; + retval = i; + goto out; + } + + if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) { + retval = do_load_unload(STp, file, 0); + goto out; + } + + if (mtc.mt_op == MTLOAD) { + retval = do_load_unload(STp, file, max(1, mtc.mt_count)); + goto out; + } + + if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) { + retval = do_door_lock(STp, (mtc.mt_op == MTLOCK)); + goto out; + } + + if (STp->can_partitions && STp->ready == ST_READY && + (i = switch_partition(STp)) < 0) { + retval = i; + goto out; + } + + if (mtc.mt_op == MTCOMPRESSION) + retval = st_compression(STp, (mtc.mt_count & 1)); + else + retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count); + goto out; + } + if (!STm->defined) { + retval = (-ENXIO); + goto out; + } + + if ((i = flush_buffer(STp, 0)) < 0) { + retval = i; + goto out; + } + if (STp->can_partitions && + (i = switch_partition(STp)) < 0) { + retval = i; + goto out; + } + + if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) { + struct mtget mt_status; + + if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) { + retval = (-EINVAL); + goto out; + } + + mt_status.mt_type = STp->tape_type; + mt_status.mt_dsreg = + ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) | + ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK); + mt_status.mt_blkno = STps->drv_block; + mt_status.mt_fileno = STps->drv_file; + if (STp->block_size != 0) { + if (STps->rw == ST_WRITING) + mt_status.mt_blkno += + (STp->buffer)->buffer_bytes / STp->block_size; + else if (STps->rw == ST_READING) + mt_status.mt_blkno -= + ((STp->buffer)->buffer_bytes + + STp->block_size - 1) / STp->block_size; + } + + mt_status.mt_gstat = 0; + if (STp->drv_write_prot) + mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff); + if (mt_status.mt_blkno == 0) { + if (mt_status.mt_fileno == 0) + mt_status.mt_gstat |= GMT_BOT(0xffffffff); + else + mt_status.mt_gstat |= GMT_EOF(0xffffffff); + } + mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT); + mt_status.mt_resid = STp->partition; + if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR) + mt_status.mt_gstat |= GMT_EOT(0xffffffff); + else if (STps->eof >= ST_EOM_OK) + mt_status.mt_gstat |= GMT_EOD(0xffffffff); + if (STp->density == 1) + mt_status.mt_gstat |= GMT_D_800(0xffffffff); + else if (STp->density == 2) + mt_status.mt_gstat |= GMT_D_1600(0xffffffff); + else if (STp->density == 3) + mt_status.mt_gstat |= GMT_D_6250(0xffffffff); + if (STp->ready == ST_READY) + mt_status.mt_gstat |= GMT_ONLINE(0xffffffff); + if (STp->ready == ST_NO_TAPE) + mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff); + if (STps->at_sm) + mt_status.mt_gstat |= GMT_SM(0xffffffff); + if (STm->do_async_writes || + (STm->do_buffer_writes && STp->block_size != 0) || + STp->drv_buffer != 0) + mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff); + if (STp->cleaning_req) + mt_status.mt_gstat |= GMT_CLN(0xffffffff); + + i = copy_to_user(p, &mt_status, sizeof(struct mtget)); + if (i) { + retval = (-EFAULT); + goto out; + } + + STp->recover_reg = 0; /* Clear after read */ + retval = 0; + goto out; + } /* End of MTIOCGET */ + if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) { + struct mtpos mt_pos; + if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) { + retval = (-EINVAL); + goto out; + } + if ((i = get_location(STp, &blk, &bt, 0)) < 0) { + retval = i; + goto out; + } + mt_pos.mt_blkno = blk; + i = copy_to_user(p, &mt_pos, sizeof(struct mtpos)); + if (i) + retval = (-EFAULT); + goto out; + } + up(&STp->lock); + switch (cmd_in) { + case SCSI_IOCTL_GET_IDLUN: + case SCSI_IOCTL_GET_BUS_NUMBER: + break; + default: + if (!capable(CAP_SYS_ADMIN)) + i = -EPERM; + else + i = scsi_cmd_ioctl(file, STp->disk, cmd_in, p); + if (i != -ENOTTY) + return i; + break; + } + if (!capable(CAP_SYS_ADMIN) && + (cmd_in == SCSI_IOCTL_START_UNIT || cmd_in == SCSI_IOCTL_STOP_UNIT)) + return -EPERM; + return scsi_ioctl(STp->device, cmd_in, p); + + out: + up(&STp->lock); + return retval; +} + +#ifdef CONFIG_COMPAT +static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct scsi_tape *STp = file->private_data; + struct scsi_device *sdev = STp->device; + int ret = -ENOIOCTLCMD; + if (sdev->host->hostt->compat_ioctl) { + + ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg); + + } + return ret; +} +#endif + + + +/* Try to allocate a new tape buffer. Calling function must not hold + dev_arr_lock. */ +static struct st_buffer * + new_tape_buffer(int from_initialization, int need_dma, int max_sg) +{ + int i, priority, got = 0, segs = 0; + struct st_buffer *tb; + + if (from_initialization) + priority = GFP_ATOMIC; + else + priority = GFP_KERNEL; + + i = sizeof(struct st_buffer) + (max_sg - 1) * sizeof(struct scatterlist) + + max_sg * sizeof(struct st_buf_fragment); + tb = kmalloc(i, priority); + if (!tb) { + printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n"); + return NULL; + } + memset(tb, 0, i); + tb->frp_segs = tb->orig_frp_segs = segs; + tb->use_sg = max_sg; + if (segs > 0) + tb->b_data = page_address(tb->sg[0].page); + tb->frp = (struct st_buf_fragment *)(&(tb->sg[0]) + max_sg); + + tb->in_use = 1; + tb->dma = need_dma; + tb->buffer_size = got; + + return tb; +} + + +/* Try to allocate enough space in the tape buffer */ +static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma) +{ + int segs, nbr, max_segs, b_size, priority, order, got; + + if (new_size <= STbuffer->buffer_size) + return 1; + + if (STbuffer->buffer_size <= PAGE_SIZE) + normalize_buffer(STbuffer); /* Avoid extra segment */ + + max_segs = STbuffer->use_sg; + nbr = max_segs - STbuffer->frp_segs; + if (nbr <= 0) + return 0; + + priority = GFP_KERNEL | __GFP_NOWARN; + if (need_dma) + priority |= GFP_DMA; + for (b_size = PAGE_SIZE, order=0; + b_size < new_size - STbuffer->buffer_size; + order++, b_size *= 2) + ; /* empty */ + + for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size; + segs < max_segs && got < new_size;) { + STbuffer->frp[segs].page = alloc_pages(priority, order); + if (STbuffer->frp[segs].page == NULL) { + if (new_size - got <= (max_segs - segs) * b_size / 2) { + b_size /= 2; /* Large enough for the rest of the buffers */ + order--; + continue; + } + DEB(STbuffer->buffer_size = got); + normalize_buffer(STbuffer); + return 0; + } + STbuffer->frp[segs].length = b_size; + STbuffer->frp_segs += 1; + got += b_size; + STbuffer->buffer_size = got; + segs++; + } + STbuffer->b_data = page_address(STbuffer->frp[0].page); + + return 1; +} + + +/* Release the extra buffer */ +static void normalize_buffer(struct st_buffer * STbuffer) +{ + int i, order; + + for (i = STbuffer->orig_frp_segs; i < STbuffer->frp_segs; i++) { + order = get_order(STbuffer->frp[i].length); + __free_pages(STbuffer->frp[i].page, order); + STbuffer->buffer_size -= STbuffer->frp[i].length; + } + STbuffer->frp_segs = STbuffer->orig_frp_segs; + STbuffer->frp_sg_current = 0; +} + + +/* Move data from the user buffer to the tape buffer. Returns zero (success) or + negative error code. */ +static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count) +{ + int i, cnt, res, offset; + + for (i = 0, offset = st_bp->buffer_bytes; + i < st_bp->frp_segs && offset >= st_bp->frp[i].length; i++) + offset -= st_bp->frp[i].length; + if (i == st_bp->frp_segs) { /* Should never happen */ + printk(KERN_WARNING "st: append_to_buffer offset overflow.\n"); + return (-EIO); + } + for (; i < st_bp->frp_segs && do_count > 0; i++) { + cnt = st_bp->frp[i].length - offset < do_count ? + st_bp->frp[i].length - offset : do_count; + res = copy_from_user(page_address(st_bp->frp[i].page) + offset, ubp, cnt); + if (res) + return (-EFAULT); + do_count -= cnt; + st_bp->buffer_bytes += cnt; + ubp += cnt; + offset = 0; + } + if (do_count) /* Should never happen */ + return (-EIO); + + return 0; +} + + +/* Move data from the tape buffer to the user buffer. Returns zero (success) or + negative error code. */ +static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count) +{ + int i, cnt, res, offset; + + for (i = 0, offset = st_bp->read_pointer; + i < st_bp->frp_segs && offset >= st_bp->frp[i].length; i++) + offset -= st_bp->frp[i].length; + if (i == st_bp->frp_segs) { /* Should never happen */ + printk(KERN_WARNING "st: from_buffer offset overflow.\n"); + return (-EIO); + } + for (; i < st_bp->frp_segs && do_count > 0; i++) { + cnt = st_bp->frp[i].length - offset < do_count ? + st_bp->frp[i].length - offset : do_count; + res = copy_to_user(ubp, page_address(st_bp->frp[i].page) + offset, cnt); + if (res) + return (-EFAULT); + do_count -= cnt; + st_bp->buffer_bytes -= cnt; + st_bp->read_pointer += cnt; + ubp += cnt; + offset = 0; + } + if (do_count) /* Should never happen */ + return (-EIO); + + return 0; +} + + +/* Move data towards start of buffer */ +static void move_buffer_data(struct st_buffer * st_bp, int offset) +{ + int src_seg, dst_seg, src_offset = 0, dst_offset; + int count, total; + + if (offset == 0) + return; + + total=st_bp->buffer_bytes - offset; + for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) { + src_offset = offset; + if (src_offset < st_bp->frp[src_seg].length) + break; + offset -= st_bp->frp[src_seg].length; + } + + st_bp->buffer_bytes = st_bp->read_pointer = total; + for (dst_seg=dst_offset=0; total > 0; ) { + count = min(st_bp->frp[dst_seg].length - dst_offset, + st_bp->frp[src_seg].length - src_offset); + memmove(page_address(st_bp->frp[dst_seg].page) + dst_offset, + page_address(st_bp->frp[src_seg].page) + src_offset, count); + src_offset += count; + if (src_offset >= st_bp->frp[src_seg].length) { + src_seg++; + src_offset = 0; + } + dst_offset += count; + if (dst_offset >= st_bp->frp[dst_seg].length) { + dst_seg++; + dst_offset = 0; + } + total -= count; + } +} + + +/* Fill the s/g list up to the length required for this transfer */ +static void buf_to_sg(struct st_buffer *STbp, unsigned int length) +{ + int i; + unsigned int count; + struct scatterlist *sg; + struct st_buf_fragment *frp; + + if (length == STbp->frp_sg_current) + return; /* work already done */ + + sg = &(STbp->sg[0]); + frp = STbp->frp; + for (i=count=0; count < length; i++) { + sg[i].page = frp[i].page; + if (length - count > frp[i].length) + sg[i].length = frp[i].length; + else + sg[i].length = length - count; + count += sg[i].length; + sg[i].offset = 0; + } + STbp->sg_segs = i; + STbp->frp_sg_current = length; +} + + +/* Validate the options from command line or module parameters */ +static void validate_options(void) +{ + if (buffer_kbs > 0) + st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE; + if (max_sg_segs >= ST_FIRST_SG) + st_max_sg_segs = max_sg_segs; +} + +#ifndef MODULE +/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt. + */ +static int __init st_setup(char *str) +{ + int i, len, ints[5]; + char *stp; + + stp = get_options(str, ARRAY_SIZE(ints), ints); + + if (ints[0] > 0) { + for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++) + if (parms[i].val) + *parms[i].val = ints[i + 1]; + } else { + while (stp != NULL) { + for (i = 0; i < ARRAY_SIZE(parms); i++) { + len = strlen(parms[i].name); + if (!strncmp(stp, parms[i].name, len) && + (*(stp + len) == ':' || *(stp + len) == '=')) { + if (parms[i].val) + *parms[i].val = + simple_strtoul(stp + len + 1, NULL, 0); + else + printk(KERN_WARNING "st: Obsolete parameter %s\n", + parms[i].name); + break; + } + } + if (i >= sizeof(parms) / sizeof(struct st_dev_parm)) + printk(KERN_WARNING "st: invalid parameter in '%s'\n", + stp); + stp = strchr(stp, ','); + if (stp) + stp++; + } + } + + validate_options(); + + return 1; +} + +__setup("st=", st_setup); + +#endif + +static struct file_operations st_fops = +{ + .owner = THIS_MODULE, + .read = st_read, + .write = st_write, + .ioctl = st_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = st_compat_ioctl, +#endif + .open = st_open, + .flush = st_flush, + .release = st_release, +}; + +static int st_probe(struct device *dev) +{ + struct scsi_device *SDp = to_scsi_device(dev); + struct gendisk *disk = NULL; + struct cdev *cdev = NULL; + struct scsi_tape *tpnt = NULL; + struct st_modedef *STm; + struct st_partstat *STps; + struct st_buffer *buffer; + int i, j, mode, dev_num, error; + char *stp; + u64 bounce_limit; + + if (SDp->type != TYPE_TAPE) + return -ENODEV; + if ((stp = st_incompatible(SDp))) { + printk(KERN_INFO + "st: Found incompatible tape at scsi%d, channel %d, id %d, lun %d\n", + SDp->host->host_no, SDp->channel, SDp->id, SDp->lun); + printk(KERN_INFO "st: The suggested driver is %s.\n", stp); + return -ENODEV; + } + + i = SDp->host->sg_tablesize; + if (st_max_sg_segs < i) + i = st_max_sg_segs; + buffer = new_tape_buffer(1, (SDp->host)->unchecked_isa_dma, i); + if (buffer == NULL) { + printk(KERN_ERR + "st: Can't allocate new tape buffer. Device not attached.\n"); + goto out; + } + + disk = alloc_disk(1); + if (!disk) { + printk(KERN_ERR "st: out of memory. Device not attached.\n"); + goto out_buffer_free; + } + + write_lock(&st_dev_arr_lock); + if (st_nr_dev >= st_dev_max) { + struct scsi_tape **tmp_da; + int tmp_dev_max; + + tmp_dev_max = max(st_nr_dev * 2, 8); + if (tmp_dev_max > ST_MAX_TAPES) + tmp_dev_max = ST_MAX_TAPES; + if (tmp_dev_max <= st_nr_dev) { + write_unlock(&st_dev_arr_lock); + printk(KERN_ERR "st: Too many tape devices (max. %d).\n", + ST_MAX_TAPES); + goto out_put_disk; + } + + tmp_da = kmalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC); + if (tmp_da == NULL) { + write_unlock(&st_dev_arr_lock); + printk(KERN_ERR "st: Can't extend device array.\n"); + goto out_put_disk; + } + + memset(tmp_da, 0, tmp_dev_max * sizeof(struct scsi_tape *)); + if (scsi_tapes != NULL) { + memcpy(tmp_da, scsi_tapes, + st_dev_max * sizeof(struct scsi_tape *)); + kfree(scsi_tapes); + } + scsi_tapes = tmp_da; + + st_dev_max = tmp_dev_max; + } + + for (i = 0; i < st_dev_max; i++) + if (scsi_tapes[i] == NULL) + break; + if (i >= st_dev_max) + panic("scsi_devices corrupt (st)"); + + tpnt = kmalloc(sizeof(struct scsi_tape), GFP_ATOMIC); + if (tpnt == NULL) { + write_unlock(&st_dev_arr_lock); + printk(KERN_ERR "st: Can't allocate device descriptor.\n"); + goto out_put_disk; + } + memset(tpnt, 0, sizeof(struct scsi_tape)); + tpnt->disk = disk; + sprintf(disk->disk_name, "st%d", i); + disk->private_data = &tpnt->driver; + disk->queue = SDp->request_queue; + tpnt->driver = &st_template; + scsi_tapes[i] = tpnt; + dev_num = i; + + tpnt->device = SDp; + if (SDp->scsi_level <= 2) + tpnt->tape_type = MT_ISSCSI1; + else + tpnt->tape_type = MT_ISSCSI2; + + tpnt->buffer = buffer; + + tpnt->inited = 0; + tpnt->dirty = 0; + tpnt->in_use = 0; + tpnt->drv_buffer = 1; /* Try buffering if no mode sense */ + tpnt->restr_dma = (SDp->host)->unchecked_isa_dma; + tpnt->use_pf = (SDp->scsi_level >= SCSI_2); + tpnt->density = 0; + tpnt->do_auto_lock = ST_AUTO_LOCK; + tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */ + tpnt->can_partitions = 0; + tpnt->two_fm = ST_TWO_FM; + tpnt->fast_mteom = ST_FAST_MTEOM; + tpnt->scsi2_logical = ST_SCSI2LOGICAL; + tpnt->immediate = ST_NOWAIT; + tpnt->default_drvbuffer = 0xff; /* No forced buffering */ + tpnt->partition = 0; + tpnt->new_partition = 0; + tpnt->nbr_partitions = 0; + tpnt->device->timeout = ST_TIMEOUT; + tpnt->long_timeout = ST_LONG_TIMEOUT; + tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma; + + bounce_limit = scsi_calculate_bounce_limit(SDp->host) >> PAGE_SHIFT; + if (bounce_limit > ULONG_MAX) + bounce_limit = ULONG_MAX; + tpnt->max_pfn = bounce_limit; + + for (i = 0; i < ST_NBR_MODES; i++) { + STm = &(tpnt->modes[i]); + STm->defined = 0; + STm->sysv = ST_SYSV; + STm->defaults_for_writes = 0; + STm->do_async_writes = ST_ASYNC_WRITES; + STm->do_buffer_writes = ST_BUFFER_WRITES; + STm->do_read_ahead = ST_READ_AHEAD; + STm->default_compression = ST_DONT_TOUCH; + STm->default_blksize = (-1); /* No forced size */ + STm->default_density = (-1); /* No forced density */ + } + + for (i = 0; i < ST_NBR_PARTITIONS; i++) { + STps = &(tpnt->ps[i]); + STps->rw = ST_IDLE; + STps->eof = ST_NOEOF; + STps->at_sm = 0; + STps->last_block_valid = 0; + STps->drv_block = (-1); + STps->drv_file = (-1); + } + + tpnt->current_mode = 0; + tpnt->modes[0].defined = 1; + + tpnt->density_changed = tpnt->compression_changed = + tpnt->blksize_changed = 0; + init_MUTEX(&tpnt->lock); + + st_nr_dev++; + write_unlock(&st_dev_arr_lock); + + for (mode = 0; mode < ST_NBR_MODES; ++mode) { + STm = &(tpnt->modes[mode]); + for (j=0; j < 2; j++) { + cdev = cdev_alloc(); + if (!cdev) { + printk(KERN_ERR + "st%d: out of memory. Device not attached.\n", + dev_num); + goto out_free_tape; + } + cdev->owner = THIS_MODULE; + cdev->ops = &st_fops; + + error = cdev_add(cdev, + MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)), + 1); + if (error) { + printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n", + dev_num, j ? "non" : "auto", mode); + printk(KERN_ERR "st%d: Device not attached.\n", dev_num); + goto out_free_tape; + } + STm->cdevs[j] = cdev; + + } + do_create_class_files(tpnt, dev_num, mode); + } + + for (mode = 0; mode < ST_NBR_MODES; ++mode) { + /* Make sure that the minor numbers corresponding to the four + first modes always get the same names */ + i = mode << (4 - ST_NBR_MODE_BITS); + /* Rewind entry */ + devfs_mk_cdev(MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, 0)), + S_IFCHR | S_IRUGO | S_IWUGO, + "%s/mt%s", SDp->devfs_name, st_formats[i]); + /* No-rewind entry */ + devfs_mk_cdev(MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, 1)), + S_IFCHR | S_IRUGO | S_IWUGO, + "%s/mt%sn", SDp->devfs_name, st_formats[i]); + } + disk->number = devfs_register_tape(SDp->devfs_name); + + printk(KERN_WARNING + "Attached scsi tape %s at scsi%d, channel %d, id %d, lun %d\n", + tape_name(tpnt), SDp->host->host_no, SDp->channel, SDp->id, SDp->lun); + printk(KERN_WARNING "%s: try direct i/o: %s (alignment %d B), max page reachable by HBA %lu\n", + tape_name(tpnt), tpnt->try_dio ? "yes" : "no", + queue_dma_alignment(SDp->request_queue) + 1, tpnt->max_pfn); + + return 0; + +out_free_tape: + for (mode=0; mode < ST_NBR_MODES; mode++) { + STm = &(tpnt->modes[mode]); + sysfs_remove_link(&tpnt->device->sdev_gendev.kobj, + "tape"); + for (j=0; j < 2; j++) { + if (STm->cdevs[j]) { + if (cdev == STm->cdevs[j]) + cdev = NULL; + class_simple_device_remove(MKDEV(SCSI_TAPE_MAJOR, + TAPE_MINOR(i, mode, j))); + cdev_del(STm->cdevs[j]); + } + } + } + if (cdev) + cdev_del(cdev); + write_lock(&st_dev_arr_lock); + scsi_tapes[dev_num] = NULL; + st_nr_dev--; + write_unlock(&st_dev_arr_lock); +out_put_disk: + put_disk(disk); + if (tpnt) + kfree(tpnt); +out_buffer_free: + kfree(buffer); +out: + return -ENODEV; +}; + + +static int st_remove(struct device *dev) +{ + struct scsi_device *SDp = to_scsi_device(dev); + struct scsi_tape *tpnt; + int i, j, mode; + + write_lock(&st_dev_arr_lock); + for (i = 0; i < st_dev_max; i++) { + tpnt = scsi_tapes[i]; + if (tpnt != NULL && tpnt->device == SDp) { + scsi_tapes[i] = NULL; + st_nr_dev--; + write_unlock(&st_dev_arr_lock); + devfs_unregister_tape(tpnt->disk->number); + sysfs_remove_link(&tpnt->device->sdev_gendev.kobj, + "tape"); + for (mode = 0; mode < ST_NBR_MODES; ++mode) { + j = mode << (4 - ST_NBR_MODE_BITS); + devfs_remove("%s/mt%s", SDp->devfs_name, st_formats[j]); + devfs_remove("%s/mt%sn", SDp->devfs_name, st_formats[j]); + for (j=0; j < 2; j++) { + class_simple_device_remove(MKDEV(SCSI_TAPE_MAJOR, + TAPE_MINOR(i, mode, j))); + cdev_del(tpnt->modes[mode].cdevs[j]); + tpnt->modes[mode].cdevs[j] = NULL; + } + } + tpnt->device = NULL; + + if (tpnt->buffer) { + tpnt->buffer->orig_frp_segs = 0; + normalize_buffer(tpnt->buffer); + kfree(tpnt->buffer); + } + put_disk(tpnt->disk); + kfree(tpnt); + return 0; + } + } + + write_unlock(&st_dev_arr_lock); + return 0; +} + +static void st_intr(struct scsi_cmnd *SCpnt) +{ + scsi_io_completion(SCpnt, (SCpnt->result ? 0: SCpnt->bufflen), 1); +} + +/* + * st_init_command: only called via the scsi_cmd_ioctl (block SG_IO) + * interface for REQ_BLOCK_PC commands. + */ +static int st_init_command(struct scsi_cmnd *SCpnt) +{ + struct request *rq; + + if (!(SCpnt->request->flags & REQ_BLOCK_PC)) + return 0; + + rq = SCpnt->request; + if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd)) + return 0; + + memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd)); + + if (rq_data_dir(rq) == WRITE) + SCpnt->sc_data_direction = DMA_TO_DEVICE; + else if (rq->data_len) + SCpnt->sc_data_direction = DMA_FROM_DEVICE; + else + SCpnt->sc_data_direction = DMA_NONE; + + SCpnt->timeout_per_command = rq->timeout; + SCpnt->transfersize = rq->data_len; + SCpnt->done = st_intr; + return 1; +} + +static int __init init_st(void) +{ + validate_options(); + + printk(KERN_INFO + "st: Version %s, fixed bufsize %d, s/g segs %d\n", + verstr, st_fixed_buffer_size, st_max_sg_segs); + + st_sysfs_class = class_simple_create(THIS_MODULE, "scsi_tape"); + if (IS_ERR(st_sysfs_class)) { + st_sysfs_class = NULL; + printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n"); + return 1; + } + + if (!register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0), + ST_MAX_TAPE_ENTRIES, "st")) { + if (scsi_register_driver(&st_template.gendrv) == 0) { + do_create_driverfs_files(); + return 0; + } + if (st_sysfs_class) + class_simple_destroy(st_sysfs_class); + unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0), + + ST_MAX_TAPE_ENTRIES); + } + + printk(KERN_ERR "Unable to get major %d for SCSI tapes\n", SCSI_TAPE_MAJOR); + return 1; +} + +static void __exit exit_st(void) +{ + if (st_sysfs_class) + class_simple_destroy(st_sysfs_class); + st_sysfs_class = NULL; + do_remove_driverfs_files(); + scsi_unregister_driver(&st_template.gendrv); + unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0), + ST_MAX_TAPE_ENTRIES); + kfree(scsi_tapes); + printk(KERN_INFO "st: Unloaded.\n"); +} + +module_init(init_st); +module_exit(exit_st); + + +/* The sysfs driver interface. Read-only at the moment */ +static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io); +} +static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL); + +static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size); +} +static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL); + +static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs); +} +static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL); + +static ssize_t st_version_show(struct device_driver *ddd, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr); +} +static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL); + +static void do_create_driverfs_files(void) +{ + struct device_driver *driverfs = &st_template.gendrv; + + driver_create_file(driverfs, &driver_attr_try_direct_io); + driver_create_file(driverfs, &driver_attr_fixed_buffer_size); + driver_create_file(driverfs, &driver_attr_max_sg_segs); + driver_create_file(driverfs, &driver_attr_version); +} + +static void do_remove_driverfs_files(void) +{ + struct device_driver *driverfs = &st_template.gendrv; + + driver_remove_file(driverfs, &driver_attr_version); + driver_remove_file(driverfs, &driver_attr_max_sg_segs); + driver_remove_file(driverfs, &driver_attr_fixed_buffer_size); + driver_remove_file(driverfs, &driver_attr_try_direct_io); +} + + +/* The sysfs simple class interface */ +static ssize_t st_defined_show(struct class_device *class_dev, char *buf) +{ + struct st_modedef *STm = (struct st_modedef *)class_get_devdata(class_dev); + ssize_t l = 0; + + l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined); + return l; +} + +CLASS_DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL); + +static ssize_t st_defblk_show(struct class_device *class_dev, char *buf) +{ + struct st_modedef *STm = (struct st_modedef *)class_get_devdata(class_dev); + ssize_t l = 0; + + l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize); + return l; +} + +CLASS_DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL); + +static ssize_t st_defdensity_show(struct class_device *class_dev, char *buf) +{ + struct st_modedef *STm = (struct st_modedef *)class_get_devdata(class_dev); + ssize_t l = 0; + char *fmt; + + fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n"; + l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density); + return l; +} + +CLASS_DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL); + +static ssize_t st_defcompression_show(struct class_device *class_dev, char *buf) +{ + struct st_modedef *STm = (struct st_modedef *)class_get_devdata(class_dev); + ssize_t l = 0; + + l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1); + return l; +} + +CLASS_DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL); + +static void do_create_class_files(struct scsi_tape *STp, int dev_num, int mode) +{ + int i, rew, error; + char name[10]; + struct class_device *st_class_member; + + if (!st_sysfs_class) + return; + + for (rew=0; rew < 2; rew++) { + /* Make sure that the minor numbers corresponding to the four + first modes always get the same names */ + i = mode << (4 - ST_NBR_MODE_BITS); + snprintf(name, 10, "%s%s%s", rew ? "n" : "", + STp->disk->disk_name, st_formats[i]); + st_class_member = + class_simple_device_add(st_sysfs_class, + MKDEV(SCSI_TAPE_MAJOR, + TAPE_MINOR(dev_num, mode, rew)), + &STp->device->sdev_gendev, "%s", name); + if (IS_ERR(st_class_member)) { + printk(KERN_WARNING "st%d: class_simple_device_add failed\n", + dev_num); + goto out; + } + class_set_devdata(st_class_member, &STp->modes[mode]); + + class_device_create_file(st_class_member, + &class_device_attr_defined); + class_device_create_file(st_class_member, + &class_device_attr_default_blksize); + class_device_create_file(st_class_member, + &class_device_attr_default_density); + class_device_create_file(st_class_member, + &class_device_attr_default_compression); + if (mode == 0 && rew == 0) { + error = sysfs_create_link(&STp->device->sdev_gendev.kobj, + &st_class_member->kobj, + "tape"); + if (error) { + printk(KERN_ERR + "st%d: Can't create sysfs link from SCSI device.\n", + dev_num); + } + } + } + out: + return; +} + + +/* Pin down user pages and put them into a scatter gather list. Returns <= 0 if + - mapping of all pages not successful + - any page is above max_pfn + (i.e., either completely successful or fails) +*/ +static int st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, + unsigned long uaddr, size_t count, int rw, + unsigned long max_pfn) +{ + int i, nr_pages; + + nr_pages = sgl_map_user_pages(sgl, max_pages, uaddr, count, rw); + if (nr_pages <= 0) + return nr_pages; + + for (i=0; i < nr_pages; i++) { + if (page_to_pfn(sgl[i].page) > max_pfn) + goto out_unmap; + } + return nr_pages; + + out_unmap: + sgl_unmap_user_pages(sgl, nr_pages, 0); + return 0; +} + + +/* The following functions may be useful for a larger audience. */ +static int sgl_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, + unsigned long uaddr, size_t count, int rw) +{ + int res, i, j; + unsigned int nr_pages; + struct page **pages; + + nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT; + + /* User attempted Overflow! */ + if ((uaddr + count) < uaddr) + return -EINVAL; + + /* Too big */ + if (nr_pages > max_pages) + return -ENOMEM; + + /* Hmm? */ + if (count == 0) + return 0; + + if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL) + return -ENOMEM; + + /* Try to fault in all of the necessary pages */ + down_read(¤t->mm->mmap_sem); + /* rw==READ means read from drive, write into memory area */ + res = get_user_pages( + current, + current->mm, + uaddr, + nr_pages, + rw == READ, + 0, /* don't force */ + pages, + NULL); + up_read(¤t->mm->mmap_sem); + + /* Errors and no page mapped should return here */ + if (res < nr_pages) + goto out_unmap; + + for (i=0; i < nr_pages; i++) { + /* FIXME: flush superflous for rw==READ, + * probably wrong function for rw==WRITE + */ + flush_dcache_page(pages[i]); + } + + /* Populate the scatter/gather list */ + sgl[0].page = pages[0]; + sgl[0].offset = uaddr & ~PAGE_MASK; + if (nr_pages > 1) { + sgl[0].length = PAGE_SIZE - sgl[0].offset; + count -= sgl[0].length; + for (i=1; i < nr_pages ; i++) { + sgl[i].offset = 0; + sgl[i].page = pages[i]; + sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE; + count -= PAGE_SIZE; + } + } + else { + sgl[0].length = count; + } + + kfree(pages); + return nr_pages; + + out_unmap: + if (res > 0) { + for (j=0; j < res; j++) + page_cache_release(pages[j]); + } + kfree(pages); + return res; +} + + +/* And unmap them... */ +static int sgl_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages, + int dirtied) +{ + int i; + + for (i=0; i < nr_pages; i++) { + if (dirtied && !PageReserved(sgl[i].page)) + SetPageDirty(sgl[i].page); + /* FIXME: cache flush missing for rw==READ + * FIXME: call the correct reference counting function + */ + page_cache_release(sgl[i].page); + } + + return 0; +} |
