Complete the locking and structure changes of ioctl and debug
('cat /proc/scsi/sg/debug') handling.
Signed-off-by: Douglas Gilbert <dgilb...@interlog.com>
---
This was the code that was "#if 0'-ed out 2 patches ago. It
also shuts checkpatch.pl up as it doesn't like that technique
but offers no viable substitute.
drivers/scsi/sg.c | 217 +++++++++++++++++++++++++++++-----------------
1 file changed, 136 insertions(+), 81 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 5fbdb0f40739..8b4a65340971 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -239,6 +239,7 @@ static struct sg_request *sg_add_request(struct sg_fd *sfp,
int dxfr_len,
static void sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
static struct sg_device *sg_get_dev(int min_dev);
static void sg_device_destroy(struct kref *kref);
+static const char *sg_rq_state_str(u8 rq_state, bool long_str);
#define SZ_SG_HEADER sizeof(struct sg_header) /* v1 and v2 header */
#define SZ_SG_IO_HDR sizeof(struct sg_io_hdr) /* v3 header */
@@ -359,7 +360,7 @@ sg_open(struct inode *inode, struct file *filp)
nonseekable_open(inode, filp);
if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
- return -EPERM; /* Can't lock it with read only access */
+ return -EPERM;/* not permitted, need write access for O_EXCL */
sdp = sg_get_dev(min_dev);
if (IS_ERR(sdp))
return PTR_ERR(sdp);
@@ -931,11 +932,6 @@ sg_ktime_sub_trunc(ktime_t now_ts, ktime_t ts0)
return 0;
}
-/*
- * Annotation under function arguments (i.e. '__must_hold...') states that
- * this function expects that lock to be held, a read lock is sufficient in
- * this case.
- */
static void
sg_fill_request_element(struct sg_fd *sfp, struct sg_request *srp,
struct sg_req_info *rip)
@@ -982,7 +978,6 @@ sg_fill_request_element(struct sg_fd *sfp, struct
sg_request *srp,
* Populate up to max_num struct sg_req_info objects, first from the active
* list then, if there is still room, from the free list. All elements in
* the free list should have SG_RQ_INACTIVE status.
- * See sg_fill_request_element() for note about __must_hold annotation.
*/
static void
sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo,
@@ -1031,7 +1026,6 @@ srp_state_or_detaching(struct sg_device *sdp, struct
sg_request *srp)
return ret;
}
-#if 0 /* temporary to shorten big patch */
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
@@ -1063,24 +1057,37 @@ sg_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
return -ENXIO;
if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
return -EFAULT;
- result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
- 1, read_only, 1, &srp);
+ result = sg_v3_write(sfp, filp, p, SZ_SG_IO_HDR, read_only,
+ true, &srp);
if (result < 0)
return result;
result = wait_event_interruptible(sfp->read_wait,
- (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
- if (atomic_read(&sdp->detaching))
+ srp_state_or_detaching(sdp, srp));
+
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
+ if (unlikely(result)) { /* -ERESTARTSYS because signal hit */
+ srp->orphan = true;
+ srp->rq_state = SG_RQ_INFLIGHT;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
+ SG_LOG(1, sdp, "%s: wait_event_interruptible-->%d\n",
+ __func__, result);
+ return result;
+ }
+ if (unlikely(atomic_read(&sdp->detaching))) {
+ srp->rq_state = SG_RQ_INACTIVE;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
return -ENODEV;
- write_lock_irq(&sfp->rq_list_lock);
- if (srp->done) {
- srp->done = 2;
- write_unlock_irq(&sfp->rq_list_lock);
+ } else if (likely(srp->rq_state == SG_RQ_AWAIT_READ)) {
+ srp->rq_state = SG_RQ_DONE_READ;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
return (result < 0) ? result : 0;
}
- srp->orphan = true;
- write_unlock_irq(&sfp->rq_list_lock);
- return result; /* -ERESTARTSYS because signal hit process */
+ cp = sg_rq_state_str(srp->rq_state, true);
+ SG_LOG(1, sdp, "%s: unexpected srp=0x%p state: %s\n", __func__,
+ srp, cp);
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
+ return -EPROTO; /* Logic error */
case SG_SET_TIMEOUT:
result = get_user(val, ip);
if (result)
@@ -1139,25 +1146,36 @@ 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);
- 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);
- __put_user(srp->header.pack_id, ip);
- return 0;
+ leave = false;
+ val = -1;
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
+ spin_lock(&srp->rq_entry_lck);
+ if (srp->rq_state == SG_RQ_AWAIT_READ &&
+ !srp->sync_invoc) {
+ val = srp->header.pack_id;
+ leave = true;
}
+ spin_unlock(&srp->rq_entry_lck);
+ if (leave)
+ break;
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- __put_user(-1, ip);
+ __put_user(val, ip);
+ SG_LOG(3, sdp, "%s: SG_GET_PACK_ID=%d\n", __func__, val);
return 0;
case SG_GET_NUM_WAITING:
read_lock_irqsave(&sfp->rq_list_lock, iflags);
val = 0;
- list_for_each_entry(srp, &sfp->rq_list, entry) {
- if ((1 == srp->done) && (!srp->sg_io_owned))
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
+ spin_lock(&srp->rq_entry_lck);
+ if (srp->rq_state == SG_RQ_AWAIT_READ &&
+ !srp->sync_invoc)
++val;
+ spin_unlock(&srp->rq_entry_lck);
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ SG_LOG(3, sdp, "%s: SG_GET_NUM_WAITING=%d\n", __func__,
+ val);
return put_user(val, ip);
case SG_GET_SG_TABLESIZE:
return put_user(sdp->sg_tablesize, ip);
@@ -1169,21 +1187,32 @@ 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.dlen) {
- if (sfp->mmap_called ||
- sfp->res_in_use) {
- mutex_unlock(&sfp->f_mutex);
- return -EBUSY;
+ srp = sfp->reserve_srp;
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
+ if (srp->rq_state != SG_RQ_INACTIVE) {
+ result = -EBUSY;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
+ return result;
+ } else if (val != srp->data.dlen) {
+ if (sfp->mmap_called) {
+ result = -EBUSY;
+ spin_unlock_irqrestore(&srp->rq_entry_lck,
+ iflags);
+ return result;
}
-
- sg_remove_scat(sfp, &sfp->reserve);
- sg_build_reserve(sfp, val);
- }
- mutex_unlock(&sfp->f_mutex);
- return 0;
+ srp->rq_state = SG_RQ_BUSY;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
+ sg_remove_sgat(srp);
+ if (val > 0)
+ result = sg_mk_sgat_dlen(srp, sfp, val);
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
+ srp->rq_state = SG_RQ_INACTIVE;
+ } else
+ result = 0; /* nothing needs to change */
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
+ return result;
case SG_GET_RESERVED_SIZE:
- val = min_t(int, sfp->reserve.dlen,
+ val = min_t(int, sfp->reserve_srp->data.dlen,
max_sectors_bytes(sdp->device->request_queue));
return put_user(val, ip);
case SG_SET_COMMAND_Q:
@@ -1227,7 +1256,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
if (!rinfo)
return -ENOMEM;
read_lock_irqsave(&sfp->rq_list_lock, iflags);
- sg_fill_request_table(sfp, rinfo);
+ sg_fill_request_table(sfp, rinfo, SG_MAX_QUEUE);
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
result = __copy_to_user(p, rinfo,
SZ_SG_REQ_INFO * SG_MAX_QUEUE);
@@ -1311,7 +1340,6 @@ sg_compat_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
return -ENOIOCTLCMD;
}
#endif
-#endif /* temporary to shorten big patch */
static __poll_t
sg_poll(struct file *filp, poll_table * wait)
@@ -1519,6 +1547,8 @@ sg_rq_end_io_usercontext(struct work_struct *work)
WARN_ONCE(1, "%s: sfp unexpectedly NULL\n", __func__);
return;
}
+ SG_LOG(3, sfp->parentdp, "%s: clean srp=0x%p, rq_state: %s\n",
+ __func__, srp, sg_rq_state_str(srp->rq_state, true));
sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
@@ -1644,12 +1674,10 @@ static const struct file_operations sg_fops = {
.read = sg_read,
.write = sg_write,
.poll = sg_poll,
-#if 0 /* temporary to shorten big patch */
.unlocked_ioctl = sg_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = sg_compat_ioctl,
#endif
-#endif /* temporary to shorten big patch */
.open = sg_open,
.mmap = sg_mmap,
.release = sg_release,
@@ -2748,16 +2776,12 @@ static const struct seq_operations devstrs_seq_ops = {
.show = sg_proc_seq_show_devstrs,
};
-#if 0 /* temporary to shorten big patch */
static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
-#endif /* temporary to shorten big patch */
static const struct seq_operations debug_seq_ops = {
.start = dev_seq_start,
.next = dev_seq_next,
.stop = dev_seq_stop,
-#if 0 /* temporary to shorten big patch */
.show = sg_proc_seq_show_debug,
-#endif /* temporary to shorten big patch */
};
static int
@@ -2932,37 +2956,64 @@ sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
return 0;
}
-#if 0 /* temporary to shorten big patch */
+static const char *
+sg_rq_state_str(u8 rq_state, bool long_str)
+{
+ switch (rq_state) {
+ case SG_RQ_INACTIVE:
+ return long_str ? "inactive" : "ina";
+ case SG_RQ_INFLIGHT:
+ return long_str ? "inflight" : "act";
+ case SG_RQ_AWAIT_READ:
+ return long_str ? "await_read" : "rcv";
+ case SG_RQ_DONE_READ:
+ return long_str ? "read_done" : "fin";
+ case SG_RQ_BUSY:
+ return long_str ? "busy" : "bsy";
+ default:
+ return long_str ? "unknown" : "unk";
+ }
+}
/* must be called while holding sg_index_lock */
static void
sg_proc_debug_helper(struct seq_file *s, struct sg_device *sdp)
+ __must_hold(&sg_index_lock)
+ __must_hold(&sdp->sfd_lock)
{
- int k, new_interface, blen, usg;
+ int k, dlen, usg, dur, to;
+ u32 pack_id;
+ unsigned int ms;
+ u8 rq_st, opcode;
+ bool new_ifc;
+ bool dur_valid;
struct sg_request *srp;
struct sg_fd *fp;
const struct sg_io_hdr *hp;
- const char * cp;
- unsigned int ms;
+ const char *cp;
+ const char *csp;
k = 0;
- list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
- k++;
+ list_for_each_entry(fp, &sdp->sfds, sfd_entry) {
+ ++k;
read_lock(&fp->rq_list_lock); /* irqs already disabled */
- seq_printf(s, " FD(%d): timeout=%dms dlen=%d "
- "(res)sgat=%d low_dma=%d\n", k,
- jiffies_to_msecs(fp->timeout),
- fp->reserve.dlen,
- (int)fp->reserve.num_sgat,
+ /* sgat=-1 means unavailable */
+ seq_printf(s, " FD(%d): timeout=%dms dlen=%d%slow_dma=%d\n",
+ k, jiffies_to_msecs(fp->timeout),
+ fp->reserve_srp->data.dlen, " (res)sgat=-1 ",
(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);
- list_for_each_entry(srp, &fp->rq_list, entry) {
+ seq_printf(s, " sse_seen=%d mmap_called=%d sum_fd_dlens=%u\n",
+ (int)fp->sse_seen, (int)fp->mmap_called,
+ atomic_read(&fp->sum_fd_dlens));
+ list_for_each_entry(srp, &fp->rq_list, rq_entry) {
+ spin_lock(&srp->rq_entry_lck);
hp = &srp->header;
- new_interface = (hp->interface_id == '\0') ? 0 : 1;
- if (srp->res_used) {
- if (new_interface &&
+ new_ifc = !(hp->interface_id == '\0');
+ if (srp->parentfp->reserve_srp == srp) {
+ if (new_ifc &&
(SG_FLAG_MMAP_IO & hp->flags))
cp = " mmap>> ";
else
@@ -2973,25 +3024,31 @@ sg_proc_debug_helper(struct seq_file *s, struct
sg_device *sdp)
else
cp = " ";
}
- seq_puts(s, cp);
- blen = srp->data.dlen;
+ dlen = srp->data.dlen;
usg = srp->data.num_sgat;
- seq_puts(s, srp->done ?
- ((1 == srp->done) ? "rcv:" : "fin:")
- : "act:");
- seq_printf(s, " id=%d blen=%d",
- srp->header.pack_id, blen);
- if (srp->done)
- seq_printf(s, " dur=%d", hp->duration);
- else {
+ rq_st = srp->rq_state;
+ dur = hp->duration;
+ to = fp->timeout;
+ pack_id = (u32)srp->header.pack_id;
+ opcode = srp->data.cmd_opcode;
+ spin_unlock(&srp->rq_entry_lck);
+ csp = sg_rq_state_str(rq_st, false);
+ dur_valid = (rq_st == SG_RQ_AWAIT_READ ||
+ rq_st == SG_RQ_DONE_READ);
+ seq_printf(s, "%s%s: id=%u dlen=%d", cp, csp, pack_id,
+ dlen);
+ if (dur_valid)
+ seq_printf(s, " dur=%d", dur);
+ else if (rq_st == SG_RQ_INFLIGHT) {
ms = jiffies_to_msecs(jiffies);
+ if (dur == 0) /* hp->duration may not set */
+ dur = ms; /* causes elap=0 */
seq_printf(s, " t_o/elap=%d/%d",
- (new_interface ? hp->timeout :
-
jiffies_to_msecs(fp->timeout)),
- (ms > hp->duration ? ms - hp->duration
: 0));
+ (new_ifc ? to : jiffies_to_msecs(to)),
+ (ms > dur ? ms - dur : 0));
}
- seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
- (int)srp->data.cmd_opcode);
+ seq_printf(s, "%ss sgat=%d op=0x%02x\n",
+ (fp->time_in_ns ? "n" : "m"), usg, opcode);
}
if (list_empty(&fp->rq_list))
seq_puts(s, " No requests active\n");
@@ -3037,8 +3094,6 @@ sg_proc_seq_show_debug(struct seq_file *s, void *v)
read_unlock_irqrestore(&sg_index_lock, iflags);
return 0;
}
-#endif /* temporary to shorten big patch */
-
#endif /* CONFIG_SCSI_PROC_FS */
module_init(init_sg);
--
2.17.1
