[PATCH] sg.c: update
The attachment combines the most recent patch from
Yum Rayan <yum.rayan@gmail.com> (to reduce sg stack
usage), Adrian Bunk <bunk@stusta.de> (to fix check
after use) and me (fix elapsed time calculation
(duration) on ia64 machines).
I have modified the patch from Yum Rayan so kmalloc()
in sg_read() is only called for the (rare) code paths
that need them.
Changelog:
- reduce stack usage in sg_ioctl() and sg_read()
- fix check after use in sg_mmap()
- hold duration internally in milliseconds and
check current time later than held time
Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index fd72d73..32de9aa 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -18,8 +18,8 @@
*
*/
-static int sg_version_num = 30532; /* 2 digits for each component */
-#define SG_VERSION_STR "3.5.32"
+static int sg_version_num = 30533; /* 2 digits for each component */
+#define SG_VERSION_STR "3.5.33"
/*
* D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
@@ -60,7 +60,7 @@
#ifdef CONFIG_SCSI_PROC_FS
#include <linux/proc_fs.h>
-static char *sg_version_date = "20050117";
+static char *sg_version_date = "20050328";
static int sg_proc_init(void);
static void sg_proc_cleanup(void);
@@ -330,14 +330,13 @@
static ssize_t
sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
{
- int res;
Sg_device *sdp;
Sg_fd *sfp;
Sg_request *srp;
int req_pack_id = -1;
- struct sg_header old_hdr;
- sg_io_hdr_t new_hdr;
sg_io_hdr_t *hp;
+ struct sg_header *old_hdr = NULL;
+ int retval = 0;
if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
return -ENXIO;
@@ -346,98 +345,138 @@
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
- if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
- return -EFAULT;
- if (old_hdr.reply_len < 0) {
+ old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+ if (!old_hdr)
+ return -ENOMEM;
+ if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
+ if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
- if (__copy_from_user
- (&new_hdr, buf, SZ_SG_IO_HDR))
- return -EFAULT;
- req_pack_id = new_hdr.pack_id;
+ sg_io_hdr_t *new_hdr;
+ new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
+ if (!new_hdr) {
+ retval = -ENOMEM;
+ goto free_old_hdr;
+ }
+ retval =__copy_from_user
+ (new_hdr, buf, SZ_SG_IO_HDR);
+ req_pack_id = new_hdr->pack_id;
+ kfree(new_hdr);
+ if (retval) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
}
} else
- req_pack_id = old_hdr.pack_id;
+ req_pack_id = old_hdr->pack_id;
}
srp = sg_get_rq_mark(sfp, req_pack_id);
if (!srp) { /* now wait on packet to arrive */
- if (sdp->detached)
- return -ENODEV;
- if (filp->f_flags & O_NONBLOCK)
- return -EAGAIN;
+ if (sdp->detached) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (filp->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto free_old_hdr;
+ }
while (1) {
- res = 0; /* following is a macro that beats race condition */
+ retval = 0; /* following macro beats race condition */
__wait_event_interruptible(sfp->read_wait,
- (sdp->detached || (srp = sg_get_rq_mark(sfp, req_pack_id))),
- res);
- if (sdp->detached)
- return -ENODEV;
- if (0 == res)
+ (sdp->detached ||
+ (srp = sg_get_rq_mark(sfp, req_pack_id))),
+ retval);
+ if (sdp->detached) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (0 == retval)
break;
- return res; /* -ERESTARTSYS because signal hit process */
+
+ /* -ERESTARTSYS as signal hit process */
+ goto free_old_hdr;
}
}
- if (srp->header.interface_id != '\0')
- return sg_new_read(sfp, buf, count, srp);
+ if (srp->header.interface_id != '\0') {
+ retval = sg_new_read(sfp, buf, count, srp);
+ goto free_old_hdr;
+ }
hp = &srp->header;
- memset(&old_hdr, 0, SZ_SG_HEADER);
- old_hdr.reply_len = (int) hp->timeout;
- old_hdr.pack_len = old_hdr.reply_len; /* very old, strange behaviour */
- old_hdr.pack_id = hp->pack_id;
- old_hdr.twelve_byte =
+ if (old_hdr == NULL) {
+ old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
+ if (! old_hdr) {
+ retval = -ENOMEM;
+ goto free_old_hdr;
+ }
+ }
+ memset(old_hdr, 0, SZ_SG_HEADER);
+ old_hdr->reply_len = (int) hp->timeout;
+ old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
+ old_hdr->pack_id = hp->pack_id;
+ old_hdr->twelve_byte =
((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
- old_hdr.target_status = hp->masked_status;
- old_hdr.host_status = hp->host_status;
- old_hdr.driver_status = hp->driver_status;
+ old_hdr->target_status = hp->masked_status;
+ old_hdr->host_status = hp->host_status;
+ old_hdr->driver_status = hp->driver_status;
if ((CHECK_CONDITION & hp->masked_status) ||
(DRIVER_SENSE & hp->driver_status))
- memcpy(old_hdr.sense_buffer, srp->sense_b,
- sizeof (old_hdr.sense_buffer));
+ memcpy(old_hdr->sense_buffer, srp->sense_b,
+ sizeof (old_hdr->sense_buffer));
switch (hp->host_status) {
/* This setup of 'result' is for backward compatibility and is best
ignored by the user who should use target, host + driver status */
case DID_OK:
case DID_PASSTHROUGH:
case DID_SOFT_ERROR:
- old_hdr.result = 0;
+ old_hdr->result = 0;
break;
case DID_NO_CONNECT:
case DID_BUS_BUSY:
case DID_TIME_OUT:
- old_hdr.result = EBUSY;
+ old_hdr->result = EBUSY;
break;
case DID_BAD_TARGET:
case DID_ABORT:
case DID_PARITY:
case DID_RESET:
case DID_BAD_INTR:
- old_hdr.result = EIO;
+ old_hdr->result = EIO;
break;
case DID_ERROR:
- old_hdr.result = (srp->sense_b[0] == 0 &&
+ old_hdr->result = (srp->sense_b[0] == 0 &&
hp->masked_status == GOOD) ? 0 : EIO;
break;
default:
- old_hdr.result = EIO;
+ old_hdr->result = EIO;
break;
}
/* Now copy the result back to the user buffer. */
if (count >= SZ_SG_HEADER) {
- if (__copy_to_user(buf, &old_hdr, SZ_SG_HEADER))
- return -EFAULT;
+ if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
buf += SZ_SG_HEADER;
- if (count > old_hdr.reply_len)
- count = old_hdr.reply_len;
+ if (count > old_hdr->reply_len)
+ count = old_hdr->reply_len;
if (count > SZ_SG_HEADER) {
- if ((res =
- sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)))
- return -EFAULT;
+ if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
+ retval = -EFAULT;
+ goto free_old_hdr;
+ }
}
} else
- count = (old_hdr.result == 0) ? 0 : -EIO;
+ count = (old_hdr->result == 0) ? 0 : -EIO;
sg_finish_rem_req(srp);
- return count;
+ retval = count;
+free_old_hdr:
+ if (old_hdr)
+ kfree(old_hdr);
+ return retval;
}
static ssize_t
@@ -724,7 +763,7 @@
srp->data.sglist_len = 0;
srp->data.bufflen = 0;
srp->data.buffer = NULL;
- hp->duration = jiffies; /* unit jiffies now, millisecs after done */
+ hp->duration = jiffies_to_msecs(jiffies);
/* Now send everything of to mid-level. The next time we hear about this
packet is when sg_cmd_done() is called (i.e. a callback). */
scsi_do_req(SRpnt, (void *) cmnd,
@@ -937,8 +976,13 @@
if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
return -EFAULT;
else {
- sg_req_info_t rinfo[SG_MAX_QUEUE];
- Sg_request *srp;
+ sg_req_info_t *rinfo;
+ unsigned int ms;
+
+ rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
+ GFP_KERNEL);
+ 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) {
@@ -949,19 +993,30 @@
srp->header.masked_status &
srp->header.host_status &
srp->header.driver_status;
- rinfo[val].duration =
- srp->done ? srp->header.duration :
- jiffies_to_msecs(
- jiffies - srp->header.duration);
+ 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].sg_io_owned =
+ srp->sg_io_owned;
+ rinfo[val].pack_id =
+ srp->header.pack_id;
+ rinfo[val].usr_ptr =
+ srp->header.usr_ptr;
}
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return (__copy_to_user(p, rinfo,
- SZ_SG_REQ_INFO * SG_MAX_QUEUE) ? -EFAULT : 0);
+ result = __copy_to_user(p, rinfo,
+ SZ_SG_REQ_INFO * SG_MAX_QUEUE);
+ result = result ? -EFAULT : 0;
+ kfree(rinfo);
+ return result;
}
case SG_EMULATED_HOST:
if (sdp->detached)
@@ -1208,11 +1263,12 @@
sg_mmap(struct file *filp, struct vm_area_struct *vma)
{
Sg_fd *sfp;
- unsigned long req_sz = vma->vm_end - vma->vm_start;
+ unsigned long req_sz;
Sg_scatter_hold *rsv_schp;
if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
return -ENXIO;
+ req_sz = vma->vm_end - vma->vm_start;
SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
(void *) vma->vm_start, (int) req_sz));
if (vma->vm_pgoff)
@@ -1259,6 +1315,7 @@
Sg_fd *sfp;
Sg_request *srp = NULL;
unsigned long iflags;
+ unsigned int ms;
if (SCpnt && (SRpnt = SCpnt->sc_request))
srp = (Sg_request *) SRpnt->upper_private_data;
@@ -1295,9 +1352,9 @@
SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
srp->header.resid = SCpnt->resid;
- /* N.B. unit of duration changes here from jiffies to millisecs */
- srp->header.duration =
- jiffies_to_msecs(jiffies - srp->header.duration);
+ ms = jiffies_to_msecs(jiffies);
+ srp->header.duration = (ms > srp->header.duration) ?
+ (ms - srp->header.duration) : 0;
if (0 != SRpnt->sr_result) {
struct scsi_sense_hdr sshdr;
@@ -2395,7 +2452,7 @@
}
if (resp) {
resp->nextrp = NULL;
- resp->header.duration = jiffies;
+ resp->header.duration = jiffies_to_msecs(jiffies);
resp->my_cmdp = NULL;
}
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
@@ -2990,6 +3047,7 @@
Sg_fd *fp;
const sg_io_hdr_t *hp;
const char * cp;
+ unsigned int ms;
for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
@@ -3028,10 +3086,13 @@
srp->header.pack_id, blen);
if (srp->done)
seq_printf(s, " dur=%d", hp->duration);
- else
+ else {
+ ms = jiffies_to_msecs(jiffies);
seq_printf(s, " t_o/elap=%d/%d",
- new_interface ? hp->timeout : jiffies_to_msecs(fp->timeout),
- jiffies_to_msecs(hp->duration ? (jiffies - hp->duration) : 0));
+ (new_interface ? hp->timeout :
+ jiffies_to_msecs(fp->timeout)),
+ (ms > hp->duration ? ms - hp->duration : 0));
+ }
seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
(int) srp->data.cmd_opcode);
}
