diff options
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r-- | drivers/scsi/sg.c | 284 |
1 files changed, 141 insertions, 143 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 0b60245bd740..0a38ba01b7b4 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -122,7 +122,7 @@ struct sg_device; /* forward declarations */ struct sg_fd; typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */ - struct sg_request *nextrp; /* NULL -> tail request (slist) */ + struct list_head entry; /* list entry */ struct sg_fd *parentfp; /* NULL -> not in use */ Sg_scatter_hold data; /* hold buffer, perhaps scatter list */ sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */ @@ -142,19 +142,19 @@ typedef struct sg_fd { /* holds the state of a file descriptor */ struct sg_device *parentdp; /* owning device */ wait_queue_head_t read_wait; /* queue read until command done */ rwlock_t rq_list_lock; /* protect access to list in req_arr */ + struct mutex f_mutex; /* protect against changes in this fd */ int timeout; /* defaults to SG_DEFAULT_TIMEOUT */ int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */ Sg_scatter_hold reserve; /* buffer held for this file descriptor */ - unsigned save_scat_len; /* original length of trunc. scat. element */ - Sg_request *headrp; /* head of request slist, NULL->empty */ + struct list_head rq_list; /* head of request list */ struct fasync_struct *async_qp; /* used by asynchronous notification */ Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */ - char low_dma; /* as in parent but possibly overridden to 1 */ char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */ char cmd_q; /* 1 -> allow command queuing, 0 -> don't */ unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */ char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */ char mmap_called; /* 0 -> mmap() never called on this fd */ + char res_in_use; /* 1 -> 'reserve' array in use */ struct kref f_ref; struct execute_work ew; } Sg_fd; @@ -198,7 +198,6 @@ static void sg_remove_sfp(struct kref *); static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id); static Sg_request *sg_add_request(Sg_fd * sfp); static int sg_remove_request(Sg_fd * sfp, Sg_request * srp); -static int sg_res_in_use(Sg_fd * sfp); static Sg_device *sg_get_dev(int dev); static void sg_device_destroy(struct kref *kref); @@ -525,6 +524,7 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) } else count = (old_hdr->result == 0) ? 0 : -EIO; sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); retval = count; free_old_hdr: kfree(old_hdr); @@ -565,6 +565,7 @@ sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp) } err_out: err2 = sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return err ? : err2 ? : count; } @@ -614,6 +615,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) } buf += SZ_SG_HEADER; __get_user(opcode, buf); + mutex_lock(&sfp->f_mutex); if (sfp->next_cmd_len > 0) { cmd_size = sfp->next_cmd_len; sfp->next_cmd_len = 0; /* reset so only this write() effected */ @@ -622,6 +624,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) if ((opcode >= 0xc0) && old_hdr.twelve_byte) cmd_size = 12; } + mutex_unlock(&sfp->f_mutex); SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp, "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size)); /* Determine buffer size. */ @@ -662,18 +665,14 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) * is a non-zero input_size, so emit a warning. */ if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) { - static char cmd[TASK_COMM_LEN]; - if (strcmp(current->comm, cmd)) { - printk_ratelimited(KERN_WARNING - "sg_write: data in/out %d/%d bytes " - "for SCSI command 0x%x-- guessing " - "data in;\n program %s not setting " - "count and/or reply_len properly\n", - old_hdr.reply_len - (int)SZ_SG_HEADER, - input_size, (unsigned int) cmnd[0], - current->comm); - strcpy(cmd, current->comm); - } + printk_ratelimited(KERN_WARNING + "sg_write: data in/out %d/%d bytes " + "for SCSI command 0x%x-- guessing " + "data in;\n program %s not setting " + "count and/or reply_len properly\n", + old_hdr.reply_len - (int)SZ_SG_HEADER, + input_size, (unsigned int) cmnd[0], + current->comm); } k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking); return (k < 0) ? k : count; @@ -721,7 +720,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, sg_remove_request(sfp, srp); return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */ } - if (sg_res_in_use(sfp)) { + if (sfp->res_in_use) { sg_remove_request(sfp, srp); return -EBUSY; /* reserve buffer already being used */ } @@ -752,6 +751,29 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, return count; } +static bool sg_is_valid_dxfer(sg_io_hdr_t *hp) +{ + switch (hp->dxfer_direction) { + case SG_DXFER_NONE: + if (hp->dxferp || hp->dxfer_len > 0) + return false; + return true; + case SG_DXFER_TO_DEV: + case SG_DXFER_FROM_DEV: + case SG_DXFER_TO_FROM_DEV: + if (!hp->dxferp || hp->dxfer_len == 0) + return false; + return true; + case SG_DXFER_UNKNOWN: + if ((!hp->dxferp && hp->dxfer_len) || + (hp->dxferp && hp->dxfer_len == 0)) + return false; + return true; + default: + return false; + } +} + static int sg_common_write(Sg_fd * sfp, Sg_request * srp, unsigned char *cmnd, int timeout, int blocking) @@ -772,11 +794,15 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) cmnd[0], (int) hp->cmd_len)); + if (!sg_is_valid_dxfer(hp)) + return -EINVAL; + k = sg_start_req(srp, cmnd); if (k) { SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp, "sg_common_write: start_req err=%d\n", k)); sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return k; /* probably out of space --> ENOMEM */ } if (atomic_read(&sdp->detaching)) { @@ -787,6 +813,7 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, } sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); return -ENODEV; } @@ -885,24 +912,14 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) /* strange ..., for backward compatibility */ return sfp->timeout_user; case SG_SET_FORCE_LOW_DMA: - result = get_user(val, ip); - if (result) - return result; - if (val) { - sfp->low_dma = 1; - if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) { - val = (int) sfp->reserve.bufflen; - sg_remove_scat(sfp, &sfp->reserve); - sg_build_reserve(sfp, val); - } - } else { - if (atomic_read(&sdp->detaching)) - return -ENODEV; - sfp->low_dma = sdp->device->host->unchecked_isa_dma; - } + /* + * N.B. This ioctl never worked properly, but failed to + * return an error value. So returning '0' to keep compability + * with legacy applications. + */ return 0; case SG_GET_LOW_DMA: - return put_user((int) sfp->low_dma, ip); + return put_user((int) sdp->device->host->unchecked_isa_dma, ip); case SG_GET_SCSI_ID: if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t))) return -EFAULT; @@ -936,7 +953,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) if (!access_ok(VERIFY_WRITE, ip, sizeof (int))) return -EFAULT; read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) { + list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) { read_unlock_irqrestore(&sfp->rq_list_lock, iflags); @@ -949,7 +966,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return 0; case SG_GET_NUM_WAITING: read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) { + val = 0; + list_for_each_entry(srp, &sfp->rq_list, entry) { if ((1 == srp->done) && (!srp->sg_io_owned)) ++val; } @@ -965,12 +983,18 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) return -EINVAL; val = min_t(int, val, max_sectors_bytes(sdp->device->request_queue)); + mutex_lock(&sfp->f_mutex); if (val != sfp->reserve.bufflen) { - if (sg_res_in_use(sfp) || sfp->mmap_called) + if (sfp->mmap_called || + sfp->res_in_use) { + mutex_unlock(&sfp->f_mutex); return -EBUSY; + } + sg_remove_scat(sfp, &sfp->reserve); sg_build_reserve(sfp, val); } + mutex_unlock(&sfp->f_mutex); return 0; case SG_GET_RESERVED_SIZE: val = min_t(int, sfp->reserve.bufflen, @@ -1018,35 +1042,33 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg) if (!rinfo) return -ENOMEM; read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE; - ++val, srp = srp ? srp->nextrp : srp) { + val = 0; + list_for_each_entry(srp, &sfp->rq_list, entry) { + if (val > SG_MAX_QUEUE) + break; memset(&rinfo[val], 0, SZ_SG_REQ_INFO); - if (srp) { - rinfo[val].req_state = srp->done + 1; - rinfo[val].problem = - srp->header.masked_status & - srp->header.host_status & - srp->header.driver_status; - if (srp->done) - rinfo[val].duration = - srp->header.duration; - else { - ms = jiffies_to_msecs(jiffies); - rinfo[val].duration = - (ms > srp->header.duration) ? - (ms - srp->header.duration) : 0; - } - rinfo[val].orphan = srp->orphan; - rinfo[val].sg_io_owned = - srp->sg_io_owned; - rinfo[val].pack_id = - srp->header.pack_id; - rinfo[val].usr_ptr = - srp->header.usr_ptr; + rinfo[val].req_state = srp->done + 1; + rinfo[val].problem = + srp->header.masked_status & + srp->header.host_status & + srp->header.driver_status; + if (srp->done) + rinfo[val].duration = + srp->header.duration; + else { + ms = jiffies_to_msecs(jiffies); + rinfo[val].duration = + (ms > srp->header.duration) ? + (ms - srp->header.duration) : 0; } + rinfo[val].orphan = srp->orphan; + rinfo[val].sg_io_owned = srp->sg_io_owned; + rinfo[val].pack_id = srp->header.pack_id; + rinfo[val].usr_ptr = srp->header.usr_ptr; + val++; } read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - result = __copy_to_user(p, rinfo, + result = __copy_to_user(p, rinfo, SZ_SG_REQ_INFO * SG_MAX_QUEUE); result = result ? -EFAULT : 0; kfree(rinfo); @@ -1152,7 +1174,7 @@ sg_poll(struct file *filp, poll_table * wait) return POLLERR; poll_wait(filp, &sfp->read_wait, wait); read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) { + list_for_each_entry(srp, &sfp->rq_list, entry) { /* if any read waiting, flag it */ if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned)) res = POLLIN | POLLRDNORM; @@ -1269,6 +1291,7 @@ sg_rq_end_io_usercontext(struct work_struct *work) struct sg_fd *sfp = srp->parentfp; sg_finish_rem_req(srp); + sg_remove_request(sfp, srp); kref_put(&sfp->f_ref, sg_remove_sfp); } @@ -1732,13 +1755,22 @@ sg_start_req(Sg_request *srp, unsigned char *cmd) md = &map_data; if (md) { - if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen) + mutex_lock(&sfp->f_mutex); + if (dxfer_len <= rsv_schp->bufflen && + !sfp->res_in_use) { + sfp->res_in_use = 1; sg_link_reserve(sfp, srp, dxfer_len); - else { + } else if ((hp->flags & SG_FLAG_MMAP_IO) && sfp->res_in_use) { + mutex_unlock(&sfp->f_mutex); + return -EBUSY; + } else { res = sg_build_indirect(req_schp, sfp, dxfer_len); - if (res) + if (res) { + mutex_unlock(&sfp->f_mutex); return res; + } } + mutex_unlock(&sfp->f_mutex); md->pages = req_schp->pages; md->page_order = req_schp->page_order; @@ -1806,8 +1838,6 @@ sg_finish_rem_req(Sg_request *srp) else sg_remove_scat(sfp, req_schp); - sg_remove_request(sfp, srp); - return ret; } @@ -1831,6 +1861,7 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size) int sg_tablesize = sfp->parentdp->sg_tablesize; int blk_size = buff_size, order; gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN; + struct sg_device *sdp = sfp->parentdp; if (blk_size < 0) return -EFAULT; @@ -1856,7 +1887,7 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size) scatter_elem_sz_prev = num; } - if (sfp->low_dma) + if (sdp->device->host->unchecked_isa_dma) gfp_mask |= GFP_DMA; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) @@ -2026,8 +2057,9 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp) req_schp->pages = NULL; req_schp->page_order = 0; req_schp->sglist_len = 0; - sfp->save_scat_len = 0; srp->res_used = 0; + /* Called without mutex lock to avoid deadlock */ + sfp->res_in_use = 0; } static Sg_request * @@ -2037,7 +2069,7 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) unsigned long iflags; write_lock_irqsave(&sfp->rq_list_lock, iflags); - for (resp = sfp->headrp; resp; resp = resp->nextrp) { + list_for_each_entry(resp, &sfp->rq_list, entry) { /* look for requests that are ready + not SG_IO owned */ if ((1 == resp->done) && (!resp->sg_io_owned) && ((-1 == pack_id) || (resp->header.pack_id == pack_id))) { @@ -2055,70 +2087,45 @@ sg_add_request(Sg_fd * sfp) { int k; unsigned long iflags; - Sg_request *resp; Sg_request *rp = sfp->req_arr; write_lock_irqsave(&sfp->rq_list_lock, iflags); - resp = sfp->headrp; - if (!resp) { - memset(rp, 0, sizeof (Sg_request)); - rp->parentfp = sfp; - resp = rp; - sfp->headrp = resp; - } else { - if (0 == sfp->cmd_q) - resp = NULL; /* command queuing disallowed */ - else { - for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) { - if (!rp->parentfp) - break; - } - if (k < SG_MAX_QUEUE) { - memset(rp, 0, sizeof (Sg_request)); - rp->parentfp = sfp; - while (resp->nextrp) - resp = resp->nextrp; - resp->nextrp = rp; - resp = rp; - } else - resp = NULL; + if (!list_empty(&sfp->rq_list)) { + if (!sfp->cmd_q) + goto out_unlock; + + for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) { + if (!rp->parentfp) + break; } + if (k >= SG_MAX_QUEUE) + goto out_unlock; } - if (resp) { - resp->nextrp = NULL; - resp->header.duration = jiffies_to_msecs(jiffies); - } + memset(rp, 0, sizeof (Sg_request)); + rp->parentfp = sfp; + rp->header.duration = jiffies_to_msecs(jiffies); + list_add_tail(&rp->entry, &sfp->rq_list); write_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return resp; + return rp; +out_unlock: + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); + return NULL; } /* Return of 1 for found; 0 for not found */ static int sg_remove_request(Sg_fd * sfp, Sg_request * srp) { - Sg_request *prev_rp; - Sg_request *rp; unsigned long iflags; int res = 0; - if ((!sfp) || (!srp) || (!sfp->headrp)) + if (!sfp || !srp || list_empty(&sfp->rq_list)) return res; write_lock_irqsave(&sfp->rq_list_lock, iflags); - prev_rp = sfp->headrp; - if (srp == prev_rp) { - sfp->headrp = prev_rp->nextrp; - prev_rp->parentfp = NULL; + if (!list_empty(&srp->entry)) { + list_del(&srp->entry); + srp->parentfp = NULL; res = 1; - } else { - while ((rp = prev_rp->nextrp)) { - if (srp == rp) { - prev_rp->nextrp = rp->nextrp; - rp->parentfp = NULL; - res = 1; - break; - } - prev_rp = rp; - } } write_unlock_irqrestore(&sfp->rq_list_lock, iflags); return res; @@ -2137,13 +2144,12 @@ sg_add_sfp(Sg_device * sdp) init_waitqueue_head(&sfp->read_wait); rwlock_init(&sfp->rq_list_lock); - + INIT_LIST_HEAD(&sfp->rq_list); kref_init(&sfp->f_ref); + mutex_init(&sfp->f_mutex); sfp->timeout = SG_DEFAULT_TIMEOUT; sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER; sfp->force_packid = SG_DEF_FORCE_PACK_ID; - sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ? - sdp->device->host->unchecked_isa_dma : 1; sfp->cmd_q = SG_DEF_COMMAND_Q; sfp->keep_orphan = SG_DEF_KEEP_ORPHAN; sfp->parentdp = sdp; @@ -2177,10 +2183,18 @@ sg_remove_sfp_usercontext(struct work_struct *work) { struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work); struct sg_device *sdp = sfp->parentdp; + Sg_request *srp; + unsigned long iflags; /* Cleanup any responses which were never read(). */ - while (sfp->headrp) - sg_finish_rem_req(sfp->headrp); + write_lock_irqsave(&sfp->rq_list_lock, iflags); + while (!list_empty(&sfp->rq_list)) { + srp = list_first_entry(&sfp->rq_list, Sg_request, entry); + sg_finish_rem_req(srp); + list_del(&srp->entry); + srp->parentfp = NULL; + } + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); if (sfp->reserve.bufflen > 0) { SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp, @@ -2214,20 +2228,6 @@ sg_remove_sfp(struct kref *kref) schedule_work(&sfp->ew.work); } -static int -sg_res_in_use(Sg_fd * sfp) -{ - const Sg_request *srp; - unsigned long iflags; - - read_lock_irqsave(&sfp->rq_list_lock, iflags); - for (srp = sfp->headrp; srp; srp = srp->nextrp) - if (srp->res_used) - break; - read_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return srp ? 1 : 0; -} - #ifdef CONFIG_SCSI_PROC_FS static int sg_idr_max_id(int id, void *p, void *data) @@ -2597,7 +2597,7 @@ static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v) /* must be called while holding sg_index_lock */ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) { - int k, m, new_interface, blen, usg; + int k, new_interface, blen, usg; Sg_request *srp; Sg_fd *fp; const sg_io_hdr_t *hp; @@ -2613,17 +2613,15 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) jiffies_to_msecs(fp->timeout), fp->reserve.bufflen, (int) fp->reserve.k_use_sg, - (int) fp->low_dma); + (int) sdp->device->host->unchecked_isa_dma); seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n", (int) fp->cmd_q, (int) fp->force_packid, (int) fp->keep_orphan); - for (m = 0, srp = fp->headrp; - srp != NULL; - ++m, srp = srp->nextrp) { + list_for_each_entry(srp, &fp->rq_list, entry) { hp = &srp->header; new_interface = (hp->interface_id == '\0') ? 0 : 1; if (srp->res_used) { - if (new_interface && + if (new_interface && (SG_FLAG_MMAP_IO & hp->flags)) cp = " mmap>> "; else @@ -2654,7 +2652,7 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) seq_printf(s, "ms sgat=%d op=0x%02x\n", usg, (int) srp->data.cmd_opcode); } - if (0 == m) + if (list_empty(&fp->rq_list)) seq_puts(s, " No requests active\n"); read_unlock(&fp->rq_list_lock); } |