Add ioctl(SG_IOABORT) that acts as a front-end to
blk_abort_request() which is only called if the request
is "inflight". The request to abort is matched via its
pack_id and the scope of the search is the current
device.
That scope will be fine tuned in a later patch to being
either all file descriptors belonging to the current
device, or just the current file descriptor.
Signed-off-by: Douglas Gilbert <dgilb...@interlog.com>
---
drivers/scsi/sg.c | 158 +++++++++++++++++++++++++++++++++--------
include/uapi/scsi/sg.h | 3 +
2 files changed, 132 insertions(+), 29 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 638368ed9e11..7575dd66dbef 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -111,6 +111,7 @@ enum sg_rq_state {
#define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking) invocation */
#define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
#define SG_FRQ_NO_US_XFER 4 /* no user space transfer of data */
+#define SG_FRQ_ABORTING 5 /* in process of aborting this
cmd */
#define SG_FRQ_DEACT_ORPHAN 7 /* not keeping orphan so de-activate */
#define SG_FRQ_BLK_PUT_REQ 9 /* set when blk_put_request() called */
@@ -1566,6 +1567,97 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp,
struct sg_fd *sfp,
return res;
}
+static struct sg_request *
+sg_match_request(struct sg_fd *sfp, int id)
+{
+ bool found = false;
+ struct sg_request *srp;
+
+ if (list_empty(&sfp->rq_list))
+ return NULL;
+ if (id == SG_PACK_ID_WILDCARD) /* both wildcards same value: -1 */
+ return list_first_entry_or_null(&sfp->rq_list,
+ struct sg_request, rq_entry);
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
+ if (id == srp->pack_id) {
+ found = true;
+ break;
+ }
+ }
+ return found ? srp : NULL;
+}
+
+static int
+sg_ctl_abort(struct sg_device *sdp, struct sg_fd *sfp, void __user *p)
+{
+ int res, pack_id, id;
+ unsigned long iflags;
+ struct sg_fd *o_sfp;
+ struct sg_request *srp;
+ struct sg_io_v4 io_v4;
+ struct sg_io_v4 *h4p = &io_v4;
+
+ if (copy_from_user(h4p, p, SZ_SG_IO_V4))
+ return -EFAULT;
+ if (h4p->guard != 'Q' || h4p->protocol != 0 || h4p->subprotocol != 0)
+ return -EPERM;
+ pack_id = h4p->request_extra;
+ id = pack_id;
+
+ spin_lock(&sfp->rq_list_lock);
+ srp = sg_match_request(sfp, id);
+ if (srp) {
+ spin_lock_irqsave(&srp->req_lck, iflags);
+ spin_unlock(&sfp->rq_list_lock);
+ } else { /* assume device (not just fd) scope */
+ spin_unlock(&sfp->rq_list_lock);
+ read_lock(&sdp->sfd_llock);
+ list_for_each_entry(o_sfp, &sdp->sfds, sfd_entry) {
+ if (o_sfp == sfp)
+ continue; /* already checked */
+ spin_lock(&o_sfp->rq_list_lock);
+ srp = sg_match_request(o_sfp, id);
+ if (srp) {
+ spin_lock_irqsave(&srp->req_lck, iflags);
+ spin_unlock(&o_sfp->rq_list_lock);
+ sfp = o_sfp;
+ break;
+ }
+ spin_unlock(&o_sfp->rq_list_lock);
+ }
+ read_unlock(&sdp->sfd_llock);
+ }
+ if (!srp)
+ return -ENODATA;
+
+ set_bit(SG_FRQ_ABORTING, srp->frq_bm);
+ res = 0;
+ switch (atomic_read(&srp->rq_st)) {
+ case SG_RS_BUSY:
+ clear_bit(SG_FRQ_ABORTING, srp->frq_bm);
+ res = -EBUSY; /* shouldn't occur often */
+ break;
+ case SG_RS_INACTIVE: /* inactive on rq_list not good */
+ clear_bit(SG_FRQ_ABORTING, srp->frq_bm);
+ res = -EPROTO;
+ break;
+ case SG_RS_AWAIT_RD: /* user should still do completion */
+ case SG_RS_DONE_RD:
+ clear_bit(SG_FRQ_ABORTING, srp->frq_bm);
+ break; /* nothing to do here, return 0 */
+ case SG_RS_INFLIGHT: /* only attempt abort if inflight */
+ srp->rq_result |= (DRIVER_SOFT << 24);
+ if (srp->rq)
+ blk_abort_request(srp->rq);
+ break;
+ default:
+ clear_bit(SG_FRQ_ABORTING, srp->frq_bm);
+ break;
+ }
+ spin_unlock_irqrestore(&srp->req_lck, iflags);
+ return res;
+}
+
/*
* First normalize want_rsv_sz to be >= sfp->sgat_elem_sz and
* <= max_segment_size. Exit if that is the same as old size; otherwise
@@ -1725,7 +1817,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
bool read_only = O_RDWR != (filp->f_flags & O_ACCMODE);
bool check_detach = false;
int val;
- int result = 0;
+ int res = 0;
void __user *p = uptr64(arg);
int __user *ip = p;
struct sg_device *sdp;
@@ -1753,13 +1845,21 @@ sg_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
case SG_IORECEIVE:
SG_LOG(3, sdp, "%s: SG_IORECEIVE\n", __func__);
return sg_ctl_ioreceive(filp, sfp, p);
+ case SG_IOABORT:
+ SG_LOG(3, sdp, "%s: SG_IOABORT\n", __func__);
+ if (read_only)
+ return -EPERM;
+ mutex_lock(&sfp->f_mutex);
+ res = sg_ctl_abort(sdp, sfp, p);
+ mutex_unlock(&sfp->f_mutex);
+ return res;
case SG_GET_SCSI_ID:
return sg_ctl_scsi_id(sdev, sdp, p);
case SG_SET_FORCE_PACK_ID:
SG_LOG(3, sdp, "%s: SG_SET_FORCE_PACK_ID\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
assign_bit(SG_FFD_FORCE_PACKID, sfp->ffd_bm, !!val);
return 0;
case SG_GET_PACK_ID: /* or tag of oldest "read"-able, -1 if none */
@@ -1787,31 +1887,31 @@ sg_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
return put_user(sdp->max_sgat_elems, ip);
case SG_SET_RESERVED_SIZE:
mutex_lock(&sfp->f_mutex);
- result = get_user(val, ip);
- if (likely(!result)) {
+ res = get_user(val, ip);
+ if (likely(!res)) {
if (val >= 0 && val <= (1024 * 1024 * 1024)) {
- result = sg_set_reserved_sz(sfp, val);
+ res = sg_set_reserved_sz(sfp, val);
} else {
SG_LOG(3, sdp, "%s: invalid size\n", __func__);
- result = -EINVAL;
+ res = -EINVAL;
}
}
mutex_unlock(&sfp->f_mutex);
- return result;
+ return res;
case SG_GET_RESERVED_SIZE:
mutex_lock(&sfp->f_mutex);
val = min_t(int, sfp->rsv_srp->sgat_h.buflen,
sdp->max_sgat_sz);
SG_LOG(3, sdp, "%s: SG_GET_RESERVED_SIZE=%d\n",
__func__, val);
- result = put_user(val, ip);
+ res = put_user(val, ip);
mutex_unlock(&sfp->f_mutex);
- return result;
+ return res;
case SG_SET_COMMAND_Q:
SG_LOG(3, sdp, "%s: SG_SET_COMMAND_Q\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
assign_bit(SG_FFD_CMD_Q, sfp->ffd_bm, !!val);
return 0;
case SG_GET_COMMAND_Q:
@@ -1819,9 +1919,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
return put_user(test_bit(SG_FFD_CMD_Q, sfp->ffd_bm), ip);
case SG_SET_KEEP_ORPHAN:
SG_LOG(3, sdp, "%s: SG_SET_KEEP_ORPHAN\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
assign_bit(SG_FFD_KEEP_ORPHAN, sfp->ffd_bm, !!val);
return 0;
case SG_GET_KEEP_ORPHAN:
@@ -1839,9 +1939,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
break;
case SG_SET_TIMEOUT:
SG_LOG(3, sdp, "%s: SG_SET_TIMEOUT\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
if (val < 0)
return -EIO;
if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
@@ -1867,9 +1967,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
return put_user((int)sdev->host->unchecked_isa_dma, ip);
case SG_NEXT_CMD_LEN: /* active only in v2 interface */
SG_LOG(3, sdp, "%s: SG_NEXT_CMD_LEN\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
if (val > SG_MAX_CDB_SIZE)
return -ENOMEM;
mutex_lock(&sfp->f_mutex);
@@ -1894,9 +1994,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
filp->f_mode, p);
case SG_SET_DEBUG:
SG_LOG(3, sdp, "%s: SG_SET_DEBUG\n", __func__);
- result = get_user(val, ip);
- if (unlikely(result))
- return result;
+ res = get_user(val, ip);
+ if (unlikely(res))
+ return res;
sdp->sgdebug = (u8)val;
return 0;
case BLKSECTGET:
@@ -1952,9 +2052,9 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
}
- result = sg_allow_if_err_recovery(sdp, (filp->f_flags & O_NDELAY));
- if (unlikely(result))
- return result;
+ res = sg_allow_if_err_recovery(sdp, (filp->f_flags & O_NDELAY));
+ if (unlikely(res))
+ return res;
/* ioctl that reach here are forwarded to the mid-level */
return scsi_ioctl(sdev, cmd_in, p);
}
diff --git a/include/uapi/scsi/sg.h b/include/uapi/scsi/sg.h
index db86d1ae7e29..cd58f918a784 100644
--- a/include/uapi/scsi/sg.h
+++ b/include/uapi/scsi/sg.h
@@ -356,6 +356,9 @@ struct sg_header {
/* Gives some v4 identifying info to driver, receives associated response */
#define SG_IORECEIVE _IOWR(SG_IOCTL_MAGIC_NUM, 0x42, struct sg_io_v4)
+/* Provides identifying info about a prior submission (e.g. a tag) */
+#define SG_IOABORT _IOW(SG_IOCTL_MAGIC_NUM, 0x43, struct sg_io_v4)
+
/* command queuing is always on when the v3 or v4 interface is used */
#define SG_DEF_COMMAND_Q 0
--
2.17.1
