[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>
This commit is contained in:
2005-04-02 13:51:23 -06:00 committed by James Bottomley
parent a757e64cfa
commit cb59e84083
1 changed files with 132 additions and 71 deletions

View File

@ -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 @@ static int sg_version_num = 30532; /* 2 digits for each component */
#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 @@ sg_release(struct inode *inode, struct file *filp)
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 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
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 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
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 @@ sg_ioctl(struct inode *inode, struct file *filp,
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 @@ sg_ioctl(struct inode *inode, struct file *filp,
srp->header.masked_status &
srp->header.host_status &
srp->header.driver_status;
if (srp->done)
rinfo[val].duration =
srp->done ? srp->header.duration :
jiffies_to_msecs(
jiffies - srp->header.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 @@ static int
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_cmd_done(Scsi_Cmnd * SCpnt)
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 @@ sg_cmd_done(Scsi_Cmnd * SCpnt)
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 @@ sg_add_request(Sg_fd * sfp)
}
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 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
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 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
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);
}