The internal struct sg_comm_wr_t was added when the number of
arguments to sg_common_write() became excessive. Expand this idea
so multiple calls to sg_fetch_cmnd() can be deferred until a
scsi_request object is ready to receive the command. This saves
a 252 byte stack allocation on every submit path. Prior to this
and a few other changes, the kernel infrastructure was warning
about excessive stack usage.
Also make open_cnt (count of active open()s on this device) an
atomic. Add more unlikely() and likely() hints on conditionals
Signed-off-by: Douglas Gilbert <dgilb...@interlog.com>
---
drivers/scsi/sg.c | 348 ++++++++++++++++++++++++----------------------
1 file changed, 183 insertions(+), 165 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 454abfdd4f74..638368ed9e11 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -244,7 +244,7 @@ struct sg_device { /* holds the state of each scsi generic
device */
atomic_t detaching; /* 0->device usable, 1->device detaching */
bool exclude; /* 1->open(O_EXCL) succeeded and is active */
u8 sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
- int open_cnt; /* count of opens (perhaps < num(sfds) ) */
+ atomic_t open_cnt; /* count of opens (perhaps < num(sfds) ) */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
struct kref d_ref;
@@ -252,36 +252,39 @@ struct sg_device { /* holds the state of each scsi
generic device */
struct sg_comm_wr_t { /* arguments to sg_common_write() */
int timeout;
+ int cmd_len;
unsigned long frq_bm[1]; /* see SG_FRQ_* defines above */
union { /* selector is frq_bm.SG_FRQ_IS_V4I */
struct sg_io_hdr *h3p;
struct sg_io_v4 *h4p;
};
- u8 *cmnd;
+ struct sg_fd *sfp;
+ struct file *filp;
+ const u8 __user *u_cmdp;
+ const u8 *cmdp;
};
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
/* Declarations of other static functions used before they are defined */
static int sg_proc_init(void);
-static int sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
- struct sg_io_v4 *h4p, int dxfer_dir);
+static int sg_start_req(struct sg_request *srp, struct sg_comm_wr_t *cwrp,
+ int dxfer_dir);
// static int sg_finish_rem_req(struct sg_request *srp);
static void sg_finish_scsi_blk_rq(struct sg_request *srp);
static int sg_mk_sgat(struct sg_request *srp, struct sg_fd *sfp, int minlen);
static int sg_v3_submit(struct file *filp, struct sg_fd *sfp,
struct sg_io_hdr *hp, bool sync,
struct sg_request **o_srp);
-static struct sg_request *sg_common_write(struct sg_fd *sfp,
- struct sg_comm_wr_t *cwp);
+static struct sg_request *sg_common_write(struct sg_comm_wr_t *cwp);
static int sg_rd_append(struct sg_request *srp, void __user *outp,
int num_xfer);
static void sg_remove_sgat(struct sg_request *srp);
static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
static struct sg_request *sg_find_srp_by_id(struct sg_fd *sfp, int id);
-static struct sg_request *sg_add_request(struct sg_fd *sfp, int dxfr_len,
- struct sg_comm_wr_t *cwrp);
+static struct sg_request *sg_add_request(struct sg_comm_wr_t *cwrp,
+ int dxfr_len);
static void sg_deact_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);
@@ -322,7 +325,7 @@ static void sg_rep_rq_state_fail(struct sg_device *sdp,
char _b[160]; \
int _tid = (current ? current->pid : -1); \
\
- if ((sdp) && (sdp)->disk) { \
+ if (likely((sdp) && (sdp)->disk)) { \
snprintf(_b, sizeof(_b), "%s: tid=%d", \
(sdp)->disk->disk_name, _tid); \
SCSI_LOG_TIMEOUT(depth, \
@@ -372,37 +375,38 @@ static int
sg_wait_open_event(struct sg_device *sdp, bool o_excl)
__must_hold(&sdp->open_rel_lock)
{
- int retval = 0;
+ int res = 0;
if (unlikely(o_excl)) {
- while (sdp->open_cnt > 0) {
+ while (atomic_read(&sdp->open_cnt) > 0) {
mutex_unlock(&sdp->open_rel_lock);
- retval = wait_event_interruptible(sdp->open_wait,
- (unlikely(atomic_read(&sdp->detaching)) ||
- !sdp->open_cnt));
+ res = wait_event_interruptible
+ (sdp->open_wait,
+ (unlikely(atomic_read(&sdp->detaching)) ||
+ !atomic_read(&sdp->open_cnt)));
mutex_lock(&sdp->open_rel_lock);
- if (retval) /* -ERESTARTSYS */
- return retval;
+ if (unlikely(res)) /* -ERESTARTSYS */
+ return res;
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
}
} else {
while (unlikely(sdp->exclude)) {
mutex_unlock(&sdp->open_rel_lock);
- retval = wait_event_interruptible(sdp->open_wait,
- unlikely((atomic_read(&sdp->detaching)) ||
- !sdp->exclude));
+ res = wait_event_interruptible
+ (sdp->open_wait,
+ unlikely((atomic_read(&sdp->detaching)) ||
+ !sdp->exclude));
mutex_lock(&sdp->open_rel_lock);
- if (retval) /* -ERESTARTSYS */
- return retval;
+ if (unlikely(res)) /* -ERESTARTSYS */
+ return res;
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
}
}
-
- return retval;
+ return res;
}
/*
@@ -415,7 +419,7 @@ sg_wait_open_event(struct sg_device *sdp, bool o_excl)
static inline int
sg_allow_if_err_recovery(struct sg_device *sdp, bool non_block)
{
- if (!sdp)
+ if (unlikely(!sdp))
return -EPROTO;
if (non_block)
return 0;
@@ -439,7 +443,7 @@ sg_open(struct inode *inode, struct file *filp)
int op_flags = filp->f_flags;
struct sg_device *sdp;
struct sg_fd *sfp;
- int retval;
+ int res;
nonseekable_open(inode, filp);
o_excl = !!(op_flags & O_EXCL);
@@ -450,69 +454,70 @@ sg_open(struct inode *inode, struct file *filp)
if (IS_ERR(sdp))
return PTR_ERR(sdp);
SG_LOG(3, sdp, "%s: minor=%d, op_flags=0x%x; %s count prior=%d%s\n",
- __func__, min_dev, op_flags, "device open", sdp->open_cnt,
- (non_block ? " O_NONBLOCK" : ""));
+ __func__, min_dev, op_flags, "device open",
+ atomic_read(&sdp->open_cnt), (non_block ? " O_NONBLOCK" : ""));
/* This driver's module count bumped by fops_get in <linux/fs.h> */
/* Prevent the device driver from vanishing while we sleep */
- retval = scsi_device_get(sdp->device);
- if (retval)
+ res = scsi_device_get(sdp->device);
+ if (unlikely(res))
goto sg_put;
- retval = scsi_autopm_get_device(sdp->device);
- if (retval)
+ res = scsi_autopm_get_device(sdp->device);
+ if (unlikely(res))
goto sdp_put;
- retval = sg_allow_if_err_recovery(sdp, non_block);
- if (retval)
+ res = sg_allow_if_err_recovery(sdp, non_block);
+ if (unlikely(res))
goto error_out;
mutex_lock(&sdp->open_rel_lock);
if (op_flags & O_NONBLOCK) {
- if (o_excl) {
- if (sdp->open_cnt > 0) {
- retval = -EBUSY;
+ if (unlikely(o_excl)) {
+ if (atomic_read(&sdp->open_cnt) > 0) {
+ res = -EBUSY;
goto error_mutex_locked;
}
} else {
- if (sdp->exclude) {
- retval = -EBUSY;
+ if (unlikely(sdp->exclude)) {
+ res = -EBUSY;
goto error_mutex_locked;
}
}
} else {
- retval = sg_wait_open_event(sdp, o_excl);
- if (retval) /* -ERESTARTSYS or -ENODEV */
+ res = sg_wait_open_event(sdp, o_excl);
+ if (unlikely(res)) /* -ERESTARTSYS or -ENODEV */
goto error_mutex_locked;
}
/* N.B. at this point we are holding the open_rel_lock */
- if (o_excl)
+ if (unlikely(o_excl))
sdp->exclude = true;
- if (sdp->open_cnt < 1) { /* no existing opens */
+ if (atomic_read(&sdp->open_cnt) < 1) { /* no existing opens */
sdp->sgdebug = 0;
/* Next done in sg_alloc(), repeat here to pick up change? */
sg_calc_sgat_param(sdp);
}
sfp = sg_add_sfp(sdp);
if (IS_ERR(sfp)) {
- retval = PTR_ERR(sfp);
+ res = PTR_ERR(sfp);
goto out_undo;
}
filp->private_data = sfp;
sfp->tid = (current ? current->pid : -1);
- sdp->open_cnt++;
+ sfp->tid = (current ? current->pid : -1);
+ atomic_inc(&sdp->open_cnt);
mutex_unlock(&sdp->open_rel_lock);
- retval = 0;
+ res = 0;
sg_put:
kref_put(&sdp->d_ref, sg_device_destroy);
- return retval;
+ return res;
out_undo:
- if (o_excl) {
+ if (unlikely(o_excl)) {
sdp->exclude = false; /* undo if error */
wake_up_interruptible(&sdp->open_wait);
}
@@ -541,21 +546,21 @@ sg_release(struct inode *inode, struct file *filp)
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sdp, "%s: device open count prior=%d\n", __func__,
- sdp->open_cnt);
- if (!sdp)
+ atomic_read(&sdp->open_cnt));
+ if (unlikely(!sdp))
return -ENXIO;
mutex_lock(&sdp->open_rel_lock);
scsi_autopm_put_device(sdp->device);
kref_put(&sfp->f_ref, sg_remove_sfp);
- sdp->open_cnt--;
+ atomic_dec(&sdp->open_cnt);
/* possibly many open()s waiting on exlude clearing, start many;
* only open(O_EXCL)s wait on 0==open_cnt so only start one */
- if (sdp->exclude) {
+ if (unlikely(sdp->exclude)) {
sdp->exclude = false;
wake_up_interruptible_all(&sdp->open_wait);
- } else if (0 == sdp->open_cnt) {
+ } else if (atomic_read(&sdp->open_cnt) == 0) {
wake_up_interruptible(&sdp->open_wait);
}
mutex_unlock(&sdp->open_rel_lock);
@@ -577,7 +582,6 @@ sg_write(struct file *filp, const char __user *p, size_t
count, loff_t *ppos)
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
- u8 cmnd[SG_MAX_CDB_SIZE];
struct sg_header ov2hdr;
struct sg_io_hdr v3hdr;
struct sg_header *ohp = &ov2hdr;
@@ -585,14 +589,14 @@ sg_write(struct file *filp, const char __user *p, size_t
count, loff_t *ppos)
struct sg_comm_wr_t cwr;
res = sg_check_file_access(filp, __func__);
- if (res)
+ if (unlikely(res))
return res;
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sdp, "%s: write(3rd arg) count=%d\n", __func__, (int)count);
res = sg_allow_if_err_recovery(sdp, !!(filp->f_flags & O_NONBLOCK));
- if (res)
+ if (unlikely(res))
return res;
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
@@ -664,9 +668,6 @@ sg_write(struct file *filp, const char __user *p, size_t
count, loff_t *ppos)
h3p->flags = input_size; /* structure abuse ... */
h3p->pack_id = ohp->pack_id;
h3p->usr_ptr = NULL;
- cmnd[0] = opcode;
- if (__copy_from_user(cmnd + 1, p + 1, cmd_size - 1))
- return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
* but it is possible that the app intended SG_DXFER_TO_DEV, because
@@ -677,13 +678,17 @@ sg_write(struct file *filp, const char __user *p, size_t
count, loff_t *ppos)
"%s: 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",
__func__, ohp->reply_len - (int)SZ_SG_HEADER,
- input_size, (unsigned int)cmnd[0], current->comm);
+ input_size, (unsigned int)opcode, current->comm);
}
cwr.frq_bm[0] = 0; /* initial state clear for all req flags */
cwr.h3p = h3p;
cwr.timeout = sfp->timeout;
- cwr.cmnd = cmnd;
- srp = sg_common_write(sfp, &cwr);
+ cwr.cmd_len = cmd_size;
+ cwr.filp = filp;
+ cwr.sfp = sfp;
+ cwr.u_cmdp = p;
+ cwr.cmdp = NULL;
+ srp = sg_common_write(&cwr);
return (IS_ERR(srp)) ? PTR_ERR(srp) : (int)count;
}
@@ -712,11 +717,9 @@ static int
sg_v3_submit(struct file *filp, struct sg_fd *sfp, struct sg_io_hdr *hp,
bool sync, struct sg_request **o_srp)
{
- int res, timeout;
unsigned long ul_timeout;
struct sg_request *srp;
struct sg_comm_wr_t cwr;
- u8 cmnd[SG_MAX_CDB_SIZE];
/* now doing v3 blocking (sync) or non-blocking submission */
if (hp->flags & SG_FLAG_MMAP_IO) {
@@ -730,16 +733,16 @@ sg_v3_submit(struct file *filp, struct sg_fd *sfp, struct
sg_io_hdr *hp,
/* when v3 seen, allow cmd_q on this fd (def: no cmd_q) */
set_bit(SG_FFD_CMD_Q, sfp->ffd_bm);
ul_timeout = msecs_to_jiffies(hp->timeout);
- timeout = min_t(unsigned long, ul_timeout, INT_MAX);
- res = sg_fetch_cmnd(filp, sfp, hp->cmdp, hp->cmd_len, cmnd);
- if (res)
- return res;
cwr.frq_bm[0] = 0;
assign_bit(SG_FRQ_SYNC_INVOC, cwr.frq_bm, (int)sync);
cwr.h3p = hp;
- cwr.timeout = timeout;
- cwr.cmnd = cmnd;
- srp = sg_common_write(sfp, &cwr);
+ cwr.timeout = min_t(unsigned long, ul_timeout, INT_MAX);
+ cwr.cmd_len = hp->cmd_len;
+ cwr.filp = filp;
+ cwr.sfp = sfp;
+ cwr.u_cmdp = hp->cmdp;
+ cwr.cmdp = NULL;
+ srp = sg_common_write(&cwr);
if (IS_ERR(srp))
return PTR_ERR(srp);
if (o_srp)
@@ -751,12 +754,15 @@ static int
sg_v4_submit(struct file *filp, struct sg_fd *sfp, void __user *p,
struct sg_io_v4 *h4p, bool sync, struct sg_request **o_srp)
{
- int timeout, res;
+ int res = 0;
unsigned long ul_timeout;
struct sg_request *srp;
struct sg_comm_wr_t cwr;
- u8 cmnd[SG_MAX_CDB_SIZE];
+ memset(&cwr, 0, sizeof(cwr));
+ cwr.filp = filp;
+ cwr.sfp = sfp;
+ cwr.h4p = h4p;
if (h4p->flags & SG_FLAG_MMAP_IO) {
int len = 0;
@@ -774,18 +780,15 @@ sg_v4_submit(struct file *filp, struct sg_fd *sfp, void
__user *p,
/* once v4 (or v3) seen, allow cmd_q on this fd (def: no cmd_q) */
set_bit(SG_FFD_CMD_Q, sfp->ffd_bm);
ul_timeout = msecs_to_jiffies(h4p->timeout);
- timeout = min_t(unsigned long, ul_timeout, INT_MAX);
- res = sg_fetch_cmnd(filp, sfp, cuptr64(h4p->request), h4p->request_len,
- cmnd);
- if (res)
- return res;
cwr.frq_bm[0] = 0;
assign_bit(SG_FRQ_SYNC_INVOC, cwr.frq_bm, (int)sync);
set_bit(SG_FRQ_IS_V4I, cwr.frq_bm);
cwr.h4p = h4p;
- cwr.timeout = timeout;
- cwr.cmnd = cmnd;
- srp = sg_common_write(sfp, &cwr);
+ cwr.timeout = min_t(unsigned long, ul_timeout, INT_MAX);
+ cwr.cmd_len = h4p->request_len;
+ cwr.u_cmdp = cuptr64(h4p->request);
+ cwr.cmdp = NULL;
+ srp = sg_common_write(&cwr);
if (IS_ERR(srp))
return PTR_ERR(srp);
if (o_srp)
@@ -802,7 +805,7 @@ sg_ctl_iosubmit(struct file *filp, struct sg_fd *sfp, void
__user *p)
struct sg_device *sdp = sfp->parentdp;
res = sg_allow_if_err_recovery(sdp, (filp->f_flags & O_NONBLOCK));
- if (res)
+ if (unlikely(res))
return res;
if (copy_from_user(hdr_store, p, SZ_SG_IO_V4))
return -EFAULT;
@@ -863,13 +866,14 @@ sg_rstate_chg(struct sg_request *srp, enum sg_rq_state
old_st,
* N.B. pack_id placed in sg_io_v4::request_extra field.
*/
static struct sg_request *
-sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t *cwrp)
+sg_common_write(struct sg_comm_wr_t *cwrp)
{
int res = 0;
- int dxfr_len, dir, cmd_len;
+ int dxfr_len, dir;
int pack_id = SG_PACK_ID_WILDCARD;
u32 rq_flags;
- struct sg_device *sdp = sfp->parentdp;
+ struct sg_fd *fp = cwrp->sfp;
+ struct sg_device *sdp = fp->parentdp;
struct sg_request *srp;
struct sg_io_hdr *hi_p;
struct sg_io_v4 *h4p;
@@ -901,7 +905,7 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t
*cwrp)
if (dxfr_len >= SZ_256M)
return ERR_PTR(-EINVAL);
- srp = sg_add_request(sfp, dxfr_len, cwrp);
+ srp = sg_add_request(cwrp, dxfr_len);
if (IS_ERR(srp))
return srp;
srp->rq_flags = rq_flags;
@@ -914,18 +918,16 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t
*cwrp)
srp->s_hdr4.max_sb_len = h4p->max_response_len;
srp->s_hdr4.cmd_len = h4p->request_len;
srp->s_hdr4.dir = dir;
- cmd_len = h4p->request_len;
} else { /* v3 interface active */
- cmd_len = hi_p->cmd_len;
memcpy(&srp->s_hdr3, hi_p, sizeof(srp->s_hdr3));
}
- srp->cmd_opcode = cwrp->cmnd[0];/* hold opcode of command for debug */
- SG_LOG(4, sdp, "%s: opcode=0x%02x, cdb_sz=%d, pack_id=%d\n", __func__,
- (int)cwrp->cmnd[0], cmd_len, pack_id);
- res = sg_start_req(srp, cwrp->cmnd, cmd_len, h4p, dir);
- if (res < 0) /* probably out of space --> -ENOMEM */
+ res = sg_start_req(srp, cwrp, dir);
+ if (unlikely(res < 0)) /* probably out of space --> -ENOMEM */
goto err_out;
+ SG_LOG(4, sdp, "%s: opcode=0x%02x, cdb_sz=%d, pack_id=%d\n", __func__,
+ srp->cmd_opcode, cwrp->cmd_len, pack_id);
+
if (unlikely(atomic_read(&sdp->detaching))) {
res = -ENODEV;
goto err_out;
@@ -936,11 +938,11 @@ sg_common_write(struct sg_fd *sfp, struct sg_comm_wr_t
*cwrp)
}
srp->rq->timeout = cwrp->timeout;
- sg_execute_cmd(sfp, srp);
+ sg_execute_cmd(fp, srp);
return srp;
err_out:
sg_finish_scsi_blk_rq(srp);
- sg_deact_request(sfp, srp);
+ sg_deact_request(fp, srp);
return ERR_PTR(res);
}
@@ -1155,7 +1157,7 @@ sg_ctl_ioreceive(struct file *filp, struct sg_fd *sfp,
void __user *p)
struct sg_request *srp;
res = sg_allow_if_err_recovery(sdp, non_block);
- if (res)
+ if (unlikely(res))
return res;
/* Get first three 32 bit integers: guard, proto+subproto */
if (copy_from_user(h4p, p, SZ_SG_IO_V4))
@@ -1179,8 +1181,8 @@ sg_ctl_ioreceive(struct file *filp, struct sg_fd *sfp,
void __user *p)
id));
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
- if (res) /* -ERESTARTSYS as signal hit process */
- return res;
+ if (unlikely(res))
+ return res; /* signal --> -ERESTARTSYS */
} /* now srp should be valid */
return sg_v4_receive(sfp, srp, p, h4p);
}
@@ -1531,7 +1533,7 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp,
struct sg_fd *sfp,
SG_LOG(3, sdp, "%s: SG_IO%s\n", __func__,
((filp->f_flags & O_NONBLOCK) ? " O_NONBLOCK ignored" : ""));
res = sg_allow_if_err_recovery(sdp, false);
- if (res)
+ if (unlikely(res))
return res;
if (atomic_read(&sdp->detaching))
return -ENODEV;
@@ -1556,7 +1558,7 @@ sg_ctl_sg_io(struct file *filp, struct sg_device *sdp,
struct sg_fd *sfp,
if (!srp) /* mrq case: already processed all responses */
return res;
res = sg_wait_event_srp(filp, sfp, p, h4p, srp);
- if (res) {
+ if (unlikely(res)) {
SG_LOG(1, sdp, "%s: %s=0x%p state: %s\n", __func__,
"unexpected srp", srp,
sg_rq_st_str(atomic_read(&srp->rq_st), false));
@@ -1605,7 +1607,7 @@ sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz)
/* new sg_request object, sized correctly is now available */
spin_lock_irqsave(&sfp->rq_list_lock, iflags);
o_srp = sfp->rsv_srp;
- if (!o_srp) {
+ if (unlikely(!o_srp)) {
res = -EPROTO;
goto wr_unlock;
}
@@ -1736,7 +1738,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
sdp = sfp->parentdp;
SG_LOG(6, sdp, "%s: cmd=0x%x, O_NONBLOCK=%d\n", __func__, cmd_in,
!!(filp->f_flags & O_NONBLOCK));
- if (!sdp)
+ if (unlikely(!sdp))
return -ENXIO;
if (unlikely(atomic_read(&sdp->detaching)))
return -ENODEV;
@@ -1756,7 +1758,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_FORCE_PACK_ID:
SG_LOG(3, sdp, "%s: SG_SET_FORCE_PACK_ID\n", __func__);
result = get_user(val, ip);
- if (result)
+ if (unlikely(result))
return result;
assign_bit(SG_FFD_FORCE_PACKID, sfp->ffd_bm, !!val);
return 0;
@@ -1786,7 +1788,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_RESERVED_SIZE:
mutex_lock(&sfp->f_mutex);
result = get_user(val, ip);
- if (!result) {
+ if (likely(!result)) {
if (val >= 0 && val <= (1024 * 1024 * 1024)) {
result = sg_set_reserved_sz(sfp, val);
} else {
@@ -1808,7 +1810,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_COMMAND_Q:
SG_LOG(3, sdp, "%s: SG_SET_COMMAND_Q\n", __func__);
result = get_user(val, ip);
- if (result)
+ if (unlikely(result))
return result;
assign_bit(SG_FFD_CMD_Q, sfp->ffd_bm, !!val);
return 0;
@@ -1818,7 +1820,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_KEEP_ORPHAN:
SG_LOG(3, sdp, "%s: SG_SET_KEEP_ORPHAN\n", __func__);
result = get_user(val, ip);
- if (result)
+ if (unlikely(result))
return result;
assign_bit(SG_FFD_KEEP_ORPHAN, sfp->ffd_bm, !!val);
return 0;
@@ -1838,7 +1840,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_TIMEOUT:
SG_LOG(3, sdp, "%s: SG_SET_TIMEOUT\n", __func__);
result = get_user(val, ip);
- if (result)
+ if (unlikely(result))
return result;
if (val < 0)
return -EIO;
@@ -1866,7 +1868,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
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 (result)
+ if (unlikely(result))
return result;
if (val > SG_MAX_CDB_SIZE)
return -ENOMEM;
@@ -1893,7 +1895,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
case SG_SET_DEBUG:
SG_LOG(3, sdp, "%s: SG_SET_DEBUG\n", __func__);
result = get_user(val, ip);
- if (result)
+ if (unlikely(result))
return result;
sdp->sgdebug = (u8)val;
return 0;
@@ -1951,7 +1953,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
return -ENODEV;
}
result = sg_allow_if_err_recovery(sdp, (filp->f_flags & O_NDELAY));
- if (result)
+ if (unlikely(result))
return result;
/* ioctl that reach here are forwarded to the mid-level */
return scsi_ioctl(sdev, cmd_in, p);
@@ -1967,7 +1969,7 @@ sg_compat_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
sfp = filp->private_data;
sdp = sfp->parentdp;
- if (!sdp)
+ if (unlikely(!sdp))
return -ENXIO;
sdev = sdp->device;
@@ -1996,7 +1998,7 @@ sg_poll(struct file *filp, poll_table * wait)
sfp = filp->private_data;
sdp = sfp->parentdp;
- if (!sdp)
+ if (unlikely(!sdp))
return EPOLLERR;
poll_wait(filp, &sfp->read_wait, wait);
if (atomic_read(&sfp->waiting) > 0)
@@ -2022,7 +2024,7 @@ sg_fasync(int fd, struct file *filp, int mode)
sfp = filp->private_data;
sdp = sfp->parentdp;
SG_LOG(3, sdp, "%s: mode(%s)\n", __func__, (mode ? "add" : "remove"));
- if (!sdp)
+ if (unlikely(!sdp))
return -ENXIO;
return fasync_helper(fd, filp, mode, &sfp->async_qp);
}
@@ -2040,12 +2042,12 @@ sg_vma_fault(struct vm_fault *vmf)
struct sg_fd *sfp;
const char *nbp = "==NULL, bad";
- if (!vma) {
+ if (unlikely(!vma)) {
pr_warn("%s: vma%s\n", __func__, nbp);
goto out_err;
}
sfp = vma->vm_private_data;
- if (!sfp) {
+ if (unlikely(!sfp)) {
pr_warn("%s: sfp%s\n", __func__, nbp);
goto out_err;
}
@@ -2055,14 +2057,14 @@ sg_vma_fault(struct vm_fault *vmf)
goto out_err;
}
srp = sfp->rsv_srp;
- if (!srp) {
+ if (unlikely(!srp)) {
SG_LOG(1, sdp, "%s: srp%s\n", __func__, nbp);
goto out_err;
}
spin_lock_irqsave(&srp->req_lck, iflags);
rsv_schp = &srp->sgat_h;
offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= (unsigned int)rsv_schp->buflen) {
+ if (unlikely(offset >= (unsigned int)rsv_schp->buflen)) {
SG_LOG(1, sdp, "%s: offset[%lu] >= rsv.buflen\n", __func__,
offset);
goto out_err_unlock;
@@ -2108,28 +2110,28 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
struct sg_fd *sfp;
struct sg_request *srp;
- if (!filp || !vma)
+ if (unlikely(!filp || !vma))
return -ENXIO;
sfp = filp->private_data;
- if (!sfp) {
+ if (unlikely(!sfp)) {
pr_warn("sg: %s: sfp is NULL\n", __func__);
return -ENXIO;
}
req_sz = vma->vm_end - vma->vm_start;
SG_LOG(3, sfp->parentdp, "%s: vm_start=%p, len=%d\n", __func__,
(void *)vma->vm_start, (int)req_sz);
- if (vma->vm_pgoff)
+ if (unlikely(vma->vm_pgoff))
return -EINVAL; /* only an offset of 0 accepted */
/* Check reserve request is inactive and has large enough buffer */
mutex_lock(&sfp->f_mutex);
srp = sfp->rsv_srp;
spin_lock_irqsave(&srp->req_lck, iflags);
- if (SG_RS_ACTIVE(srp)) {
+ if (unlikely(SG_RS_ACTIVE(srp))) {
ret = -EBUSY;
goto out;
}
rsv_schp = &srp->sgat_h;
- if (req_sz > (unsigned long)rsv_schp->buflen) {
+ if (unlikely(req_sz > (unsigned long)rsv_schp->buflen)) {
ret = -ENOMEM;
goto out;
}
@@ -2165,12 +2167,12 @@ sg_rq_end_io_usercontext(struct work_struct *work)
ew_orph.work);
struct sg_fd *sfp;
- if (!srp) {
+ if (unlikely(!srp)) {
WARN_ONCE("%s: srp unexpectedly NULL\n", __func__);
return;
}
sfp = srp->parentfp;
- if (!sfp) {
+ if (unlikely(!sfp)) {
WARN_ONCE(1, "%s: sfp unexpectedly NULL\n", __func__);
return;
}
@@ -2190,7 +2192,7 @@ sg_check_sense(struct sg_device *sdp, struct sg_request
*srp, int sense_len)
struct scsi_request *scsi_rp = scsi_req(srp->rq);
u8 *sbp = scsi_rp ? scsi_rp->sense : NULL;
- if (!sbp)
+ if (unlikely(!sbp))
return;
driver_stat = driver_byte(rq_res);
if (driver_stat & DRIVER_SENSE) {
@@ -2205,7 +2207,7 @@ sg_check_sense(struct sg_device *sdp, struct sg_request
*srp, int sense_len)
}
}
}
- if (sdp->sgdebug > 0) {
+ if (unlikely(sdp->sgdebug > 0)) {
int scsi_stat = rq_res & 0xff;
if (scsi_stat == SAM_STAT_CHECK_CONDITION ||
@@ -2231,11 +2233,11 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
struct sg_device *sdp;
struct sg_fd *sfp;
- if (!scsi_rp) {
+ if (unlikely(!scsi_rp)) {
WARN_ONCE("%s: scsi_req(rq) unexpectedly NULL\n", __func__);
return;
}
- if (!srp) {
+ if (unlikely(!srp)) {
WARN_ONCE("%s: srp unexpectedly NULL\n", __func__);
return;
}
@@ -2360,14 +2362,14 @@ sg_alloc(struct gendisk *disk, struct scsi_device
*scsidp)
unsigned long iflags;
sdp = kzalloc(sizeof(struct sg_device), GFP_KERNEL);
- if (!sdp)
+ if (unlikely(!sdp))
return ERR_PTR(-ENOMEM);
idr_preload(GFP_KERNEL);
write_lock_irqsave(&sg_index_lock, iflags);
error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
- if (error < 0) {
+ if (unlikely(error < 0)) {
if (error == -ENOSPC) {
sdev_printk(KERN_WARNING, scsidp,
"Unable to attach sg device type=%d, minor
number exceeds %d\n",
@@ -2392,6 +2394,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
INIT_LIST_HEAD(&sdp->sfds);
init_waitqueue_head(&sdp->open_wait);
atomic_set(&sdp->detaching, 0);
+ atomic_set(&sdp->open_cnt, 0);
rwlock_init(&sdp->sfd_llock);
sg_calc_sgat_param(sdp);
sdp->index = k;
@@ -2402,7 +2405,7 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
write_unlock_irqrestore(&sg_index_lock, iflags);
idr_preload_end();
- if (error) {
+ if (unlikely(error)) {
kfree(sdp);
return ERR_PTR(error);
}
@@ -2420,7 +2423,7 @@ sg_add_device(struct device *cl_dev, struct
class_interface *cl_intf)
unsigned long iflags;
disk = alloc_disk(1);
- if (!disk) {
+ if (unlikely(!disk)) {
pr_warn("%s: alloc_disk failed\n", __func__);
return -ENOMEM;
}
@@ -2428,7 +2431,7 @@ sg_add_device(struct device *cl_dev, struct
class_interface *cl_intf)
error = -ENOMEM;
cdev = cdev_alloc();
- if (!cdev) {
+ if (unlikely(!cdev)) {
pr_warn("%s: cdev_alloc failed\n", __func__);
goto out;
}
@@ -2443,7 +2446,7 @@ sg_add_device(struct device *cl_dev, struct
class_interface *cl_intf)
}
error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
- if (error)
+ if (unlikely(error))
goto cdev_add_err;
sdp->cdev = cdev;
@@ -2517,7 +2520,7 @@ sg_remove_device(struct device *cl_dev, struct
class_interface *cl_intf)
struct sg_fd *sfp;
int val;
- if (!sdp)
+ if (unlikely(!sdp))
return;
/* want sdp->detaching non-zero as soon as possible */
val = atomic_inc_return(&sdp->detaching);
@@ -2576,7 +2579,7 @@ init_sg(void)
rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
SG_MAX_DEVS, "sg");
- if (rc)
+ if (unlikely(rc))
return rc;
pr_info("Registered %s[char major=0x%x], version: %s, date: %s\n",
@@ -2589,7 +2592,7 @@ init_sg(void)
}
sg_sysfs_valid = true;
rc = scsi_register_interface(&sg_interface);
- if (0 == rc) {
+ if (likely(rc == 0)) {
sg_proc_init();
return 0;
}
@@ -2647,8 +2650,7 @@ sg_set_map_data(const struct sg_scatter_hold *schp, bool
up_valid,
}
static int
-sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
- struct sg_io_v4 *h4p, int dxfer_dir)
+sg_start_req(struct sg_request *srp, struct sg_comm_wr_t *cwrp, int dxfer_dir)
{
bool reserved, us_xfer;
int res = 0;
@@ -2658,7 +2660,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
void __user *up;
struct request *rq;
struct scsi_request *scsi_rp;
- struct sg_fd *sfp = srp->parentfp;
+ struct sg_fd *sfp = cwrp->sfp;
struct sg_device *sdp;
struct sg_scatter_hold *req_schp;
struct request_queue *q;
@@ -2668,20 +2670,22 @@ sg_start_req(struct sg_request *srp, u8 *cmd, int
cmd_len,
struct rq_map_data map_data;
sdp = sfp->parentdp;
- if (cmd_len > BLK_MAX_CDB) { /* for longer SCSI cdb_s */
- long_cmdp = kzalloc(cmd_len, GFP_KERNEL);
+ if (cwrp->cmd_len > BLK_MAX_CDB) { /* for longer SCSI cdb_s */
+ long_cmdp = kzalloc(cwrp->cmd_len, GFP_KERNEL);
if (!long_cmdp)
return -ENOMEM;
SG_LOG(5, sdp, "%s: long_cmdp=0x%p ++\n", __func__, long_cmdp);
}
- if (h4p) {
+ if (test_bit(SG_FRQ_IS_V4I, srp->frq_bm)) {
+ struct sg_io_v4 *h4p = cwrp->h4p;
+
if (dxfer_dir == SG_DXFER_TO_DEV) {
r0w = WRITE;
up = uptr64(h4p->dout_xferp);
dxfer_len = (int)h4p->dout_xfer_len;
iov_count = h4p->dout_iovec_count;
} else if (dxfer_dir == SG_DXFER_FROM_DEV) {
- r0w = READ;
+ /* r0w = READ; */
up = uptr64(h4p->din_xferp);
dxfer_len = (int)h4p->din_xfer_len;
iov_count = h4p->din_iovec_count;
@@ -2720,10 +2724,21 @@ sg_start_req(struct sg_request *srp, u8 *cmd, int
cmd_len,
scsi_rp = scsi_req(rq);
srp->rq = rq;
- if (cmd_len > BLK_MAX_CDB)
+ if (cwrp->cmd_len > BLK_MAX_CDB)
scsi_rp->cmd = long_cmdp;
- memcpy(scsi_rp->cmd, cmd, cmd_len);
- scsi_rp->cmd_len = cmd_len;
+ if (cwrp->u_cmdp)
+ res = sg_fetch_cmnd(cwrp->filp, sfp, cwrp->u_cmdp,
+ cwrp->cmd_len, scsi_rp->cmd);
+ else if (cwrp->cmdp)
+ memcpy(scsi_rp->cmd, cwrp->cmdp, cwrp->cmd_len);
+ else
+ res = -EPROTO;
+ if (unlikely(res)) {
+ kfree(long_cmdp);
+ return res;
+ }
+ scsi_rp->cmd_len = cwrp->cmd_len;
+ srp->cmd_opcode = scsi_rp->cmd[0];
us_xfer = !(srp->rq_flags & SG_FLAG_NO_DXFER);
assign_bit(SG_FRQ_NO_US_XFER, srp->frq_bm, !us_xfer);
reserved = (sfp->rsv_srp == srp);
@@ -2756,7 +2771,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
res = sg_mk_sgat(srp, sfp, up_sz);
}
- if (res)
+ if (unlikely(res))
goto fini;
sg_set_map_data(req_schp, !!up, md);
@@ -2768,7 +2783,7 @@ sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
struct iov_iter i;
res = import_iovec(r0w, up, iov_count, 0, &iov, &i);
- if (res < 0)
+ if (unlikely(res < 0))
goto fini;
iov_iter_truncate(&i, dxfer_len);
@@ -3117,7 +3132,7 @@ sg_mk_srp_sgat(struct sg_fd *sfp, bool first, int db_len)
return n_srp;
if (db_len > 0) {
res = sg_mk_sgat(n_srp, sfp, db_len);
- if (res) {
+ if (unlikely(res)) {
kfree(n_srp);
return ERR_PTR(res);
}
@@ -3151,7 +3166,7 @@ sg_build_reserve(struct sg_fd *sfp, int buflen)
go_out = true;
}
res = sg_mk_sgat(srp, sfp, buflen);
- if (res == 0) {
+ if (likely(res == 0)) {
SG_LOG(4, sfp ? sfp->parentdp : NULL,
"%s: final buflen=%d, srp=0x%p ++\n", __func__,
buflen, srp);
@@ -3172,29 +3187,30 @@ sg_build_reserve(struct sg_fd *sfp, int buflen)
* failure returns a negated errno value twisted by ERR_PTR() macro.
*/
static struct sg_request *
-sg_add_request(struct sg_fd *sfp, int dxfr_len, struct sg_comm_wr_t *cwrp)
+sg_add_request(struct sg_comm_wr_t *cwrp, int dxfr_len)
{
bool act_empty = false;
bool mk_new_srp = true;
unsigned long iflags;
enum sg_rq_state sr_st;
+ struct sg_fd *fp = cwrp->sfp;
struct sg_request *r_srp = NULL; /* request to return */
struct sg_request *rsv_srp; /* current fd's reserve request */
__maybe_unused struct sg_device *sdp;
__maybe_unused const char *cp;
- spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- sdp = sfp->parentdp;
- rsv_srp = sfp->rsv_srp;
+ spin_lock_irqsave(&fp->rq_list_lock, iflags);
+ sdp = fp->parentdp;
+ rsv_srp = fp->rsv_srp;
cp = "";
/*
* Check the free list (fl) for candidates. Pick zero data length
* requests from the back of the fl, the rest from the front.
*/
- if (list_empty(&sfp->rq_fl)) {
+ if (list_empty(&fp->rq_fl)) {
act_empty = true;
} else if (dxfr_len < 1) { /* 0 data length requests at back of fl */
- list_for_each_entry_reverse(r_srp, &sfp->rq_fl, fl_entry) {
+ list_for_each_entry_reverse(r_srp, &fp->rq_fl, fl_entry) {
sr_st = atomic_read(&r_srp->rq_st);
if (sr_st == SG_RS_INACTIVE) {
if (likely(sg_rstate_chg(r_srp, sr_st,
@@ -3206,7 +3222,7 @@ sg_add_request(struct sg_fd *sfp, int dxfr_len, struct
sg_comm_wr_t *cwrp)
}
}
} else { /* find request with large enough dlen */
- list_for_each_entry(r_srp, &sfp->rq_fl, fl_entry) {
+ list_for_each_entry(r_srp, &fp->rq_fl, fl_entry) {
sr_st = atomic_read(&r_srp->rq_st);
if (sr_st == SG_RS_INACTIVE &&
r_srp->sgat_h.buflen >= dxfr_len) {
@@ -3221,19 +3237,19 @@ sg_add_request(struct sg_fd *sfp, int dxfr_len, struct
sg_comm_wr_t *cwrp)
}
if (mk_new_srp) { /* Need new sg_request object */
- bool allow_cmd_q = test_bit(SG_FFD_CMD_Q, sfp->ffd_bm);
+ bool allow_cmd_q = test_bit(SG_FFD_CMD_Q, fp->ffd_bm);
r_srp = NULL;
- if (!allow_cmd_q && !list_empty(&sfp->rq_list)) {
+ if (!allow_cmd_q && !list_empty(&fp->rq_list)) {
r_srp = ERR_PTR(-EDOM);
SG_LOG(6, sdp, "%s: trying 2nd req but cmd_q=false\n",
__func__);
}
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&fp->rq_list_lock, iflags);
if (IS_ERR(r_srp)) /* NULL is not an ERR here */
goto err_no_lock;
/* releasing rq_list_lock because next line could take time */
- r_srp = sg_mk_srp_sgat(sfp, act_empty, dxfr_len);
+ r_srp = sg_mk_srp_sgat(fp, act_empty, dxfr_len);
if (IS_ERR(r_srp))
goto err_no_lock;
cp = "new";
@@ -3251,11 +3267,11 @@ sg_add_request(struct sg_fd *sfp, int dxfr_len, struct
sg_comm_wr_t *cwrp)
r_srp->sgat_h.dlen = dxfr_len;/* must be <= r_srp->sgat_h.buflen */
r_srp->cmd_opcode = 0xff; /* set invalid opcode (VS), 0x0 is TUR */
if (mk_new_srp)
- spin_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_add_tail_rcu(&r_srp->rq_entry, &sfp->rq_list);
+ spin_lock_irqsave(&fp->rq_list_lock, iflags);
+ list_add_tail_rcu(&r_srp->rq_entry, &fp->rq_list);
if (!mk_new_srp)
spin_unlock(&r_srp->req_lck);
- spin_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ spin_unlock_irqrestore(&fp->rq_list_lock, iflags);
err_no_lock:
if (IS_ERR(r_srp))
SG_LOG(1, sdp, "%s: err=%ld\n", __func__, PTR_ERR(r_srp));
@@ -3353,6 +3369,8 @@ sg_add_sfp(struct sg_device *sdp)
assign_bit(SG_FFD_CMD_Q, sfp->ffd_bm, SG_DEF_COMMAND_Q);
assign_bit(SG_FFD_KEEP_ORPHAN, sfp->ffd_bm, SG_DEF_KEEP_ORPHAN);
assign_bit(SG_FFD_Q_AT_TAIL, sfp->ffd_bm, SG_DEFAULT_Q_AT);
+ atomic_set(&sfp->submitted, 0);
+ atomic_set(&sfp->waiting, 0);
/*
* SG_SCATTER_SZ initializes scatter_elem_sz but different value may
* be given as driver/module parameter (e.g. 'scatter_elem_sz=8192').
@@ -3890,7 +3908,7 @@ sg_proc_dbg_sdev(struct sg_device *sdp, char *obp, int
len, int *fd_counterp)
n += scnprintf(obp + n, len - n,
" max_sgat_sz,elems=2^%d,%d excl=%d open_cnt=%d\n",
ilog2(sdp->max_sgat_sz), sdp->max_sgat_elems,
- sdp->exclude, sdp->open_cnt);
+ sdp->exclude, atomic_read(&sdp->open_cnt));
list_for_each_entry(fp, &sdp->sfds, sfd_entry) {
++*countp;
rcu_read_lock(); /* assume irqs disabled */
--
2.17.1
