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path: root/drivers/scsi/sg.c
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Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r--drivers/scsi/sg.c239
1 files changed, 121 insertions, 118 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index dbe5b4b95df0..184c7db1e0ca 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -122,7 +122,7 @@ struct sg_device; /* forward declarations */
struct sg_fd;
typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
- struct sg_request *nextrp; /* NULL -> tail request (slist) */
+ struct list_head entry; /* list entry */
struct sg_fd *parentfp; /* NULL -> not in use */
Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
@@ -142,11 +142,11 @@ typedef struct sg_fd { /* holds the state of a file descriptor */
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
rwlock_t rq_list_lock; /* protect access to list in req_arr */
+ struct mutex f_mutex; /* protect against changes in this fd */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
Sg_scatter_hold reserve; /* buffer held for this file descriptor */
- unsigned save_scat_len; /* original length of trunc. scat. element */
- Sg_request *headrp; /* head of request slist, NULL->empty */
+ struct list_head rq_list; /* head of request list */
struct fasync_struct *async_qp; /* used by asynchronous notification */
Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
char low_dma; /* as in parent but possibly overridden to 1 */
@@ -155,6 +155,7 @@ typedef struct sg_fd { /* holds the state of a file descriptor */
unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
char mmap_called; /* 0 -> mmap() never called on this fd */
+ char res_in_use; /* 1 -> 'reserve' array in use */
struct kref f_ref;
struct execute_work ew;
} Sg_fd;
@@ -198,7 +199,6 @@ static void sg_remove_sfp(struct kref *);
static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
static Sg_request *sg_add_request(Sg_fd * sfp);
static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
-static int sg_res_in_use(Sg_fd * sfp);
static Sg_device *sg_get_dev(int dev);
static void sg_device_destroy(struct kref *kref);
@@ -614,6 +614,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
}
buf += SZ_SG_HEADER;
__get_user(opcode, buf);
+ mutex_lock(&sfp->f_mutex);
if (sfp->next_cmd_len > 0) {
cmd_size = sfp->next_cmd_len;
sfp->next_cmd_len = 0; /* reset so only this write() effected */
@@ -622,6 +623,7 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
if ((opcode >= 0xc0) && old_hdr.twelve_byte)
cmd_size = 12;
}
+ mutex_unlock(&sfp->f_mutex);
SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
"sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
/* Determine buffer size. */
@@ -721,7 +723,7 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
sg_remove_request(sfp, srp);
return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
}
- if (sg_res_in_use(sfp)) {
+ if (sfp->res_in_use) {
sg_remove_request(sfp, srp);
return -EBUSY; /* reserve buffer already being used */
}
@@ -826,6 +828,39 @@ static int max_sectors_bytes(struct request_queue *q)
return max_sectors << 9;
}
+static void
+sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
+{
+ Sg_request *srp;
+ int val;
+ unsigned int ms;
+
+ val = 0;
+ list_for_each_entry(srp, &sfp->rq_list, entry) {
+ if (val >= SG_MAX_QUEUE)
+ break;
+ rinfo[val].req_state = srp->done + 1;
+ rinfo[val].problem =
+ srp->header.masked_status &
+ srp->header.host_status &
+ srp->header.driver_status;
+ 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;
+ val++;
+ }
+}
+
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
@@ -892,7 +927,7 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return result;
if (val) {
sfp->low_dma = 1;
- if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
+ if ((0 == sfp->low_dma) && !sfp->res_in_use) {
val = (int) sfp->reserve.bufflen;
sg_remove_scat(sfp, &sfp->reserve);
sg_build_reserve(sfp, val);
@@ -938,7 +973,7 @@ 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);
- for (srp = sfp->headrp; srp; srp = srp->nextrp) {
+ 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);
@@ -951,7 +986,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return 0;
case SG_GET_NUM_WAITING:
read_lock_irqsave(&sfp->rq_list_lock, iflags);
- for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
+ val = 0;
+ list_for_each_entry(srp, &sfp->rq_list, entry) {
if ((1 == srp->done) && (!srp->sg_io_owned))
++val;
}
@@ -967,12 +1003,18 @@ 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.bufflen) {
- if (sg_res_in_use(sfp) || sfp->mmap_called)
+ if (sfp->mmap_called ||
+ sfp->res_in_use) {
+ mutex_unlock(&sfp->f_mutex);
return -EBUSY;
+ }
+
sg_remove_scat(sfp, &sfp->reserve);
sg_build_reserve(sfp, val);
}
+ mutex_unlock(&sfp->f_mutex);
return 0;
case SG_GET_RESERVED_SIZE:
val = min_t(int, sfp->reserve.bufflen,
@@ -998,6 +1040,8 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
result = get_user(val, ip);
if (result)
return result;
+ if (val > SG_MAX_CDB_SIZE)
+ return -ENOMEM;
sfp->next_cmd_len = (val > 0) ? val : 0;
return 0;
case SG_GET_VERSION_NUM:
@@ -1011,42 +1055,15 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
return -EFAULT;
else {
sg_req_info_t *rinfo;
- unsigned int ms;
- rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
- GFP_KERNEL);
+ rinfo = kzalloc(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) {
- memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
- if (srp) {
- rinfo[val].req_state = srp->done + 1;
- rinfo[val].problem =
- srp->header.masked_status &
- srp->header.host_status &
- srp->header.driver_status;
- 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;
- }
- }
+ sg_fill_request_table(sfp, rinfo);
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- result = __copy_to_user(p, rinfo,
+ result = __copy_to_user(p, rinfo,
SZ_SG_REQ_INFO * SG_MAX_QUEUE);
result = result ? -EFAULT : 0;
kfree(rinfo);
@@ -1152,7 +1169,7 @@ sg_poll(struct file *filp, poll_table * wait)
return POLLERR;
poll_wait(filp, &sfp->read_wait, wait);
read_lock_irqsave(&sfp->rq_list_lock, iflags);
- for (srp = sfp->headrp; srp; srp = srp->nextrp) {
+ list_for_each_entry(srp, &sfp->rq_list, entry) {
/* if any read waiting, flag it */
if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
res = POLLIN | POLLRDNORM;
@@ -1233,6 +1250,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
unsigned long req_sz, len, sa;
Sg_scatter_hold *rsv_schp;
int k, length;
+ int ret = 0;
if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
return -ENXIO;
@@ -1243,8 +1261,11 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
if (vma->vm_pgoff)
return -EINVAL; /* want no offset */
rsv_schp = &sfp->reserve;
- if (req_sz > rsv_schp->bufflen)
- return -ENOMEM; /* cannot map more than reserved buffer */
+ mutex_lock(&sfp->f_mutex);
+ if (req_sz > rsv_schp->bufflen) {
+ ret = -ENOMEM; /* cannot map more than reserved buffer */
+ goto out;
+ }
sa = vma->vm_start;
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
@@ -1258,7 +1279,9 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_private_data = sfp;
vma->vm_ops = &sg_mmap_vm_ops;
- return 0;
+out:
+ mutex_unlock(&sfp->f_mutex);
+ return ret;
}
static void
@@ -1725,13 +1748,25 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
md = &map_data;
if (md) {
- if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
+ mutex_lock(&sfp->f_mutex);
+ if (dxfer_len <= rsv_schp->bufflen &&
+ !sfp->res_in_use) {
+ sfp->res_in_use = 1;
sg_link_reserve(sfp, srp, dxfer_len);
- else {
+ } else if (hp->flags & SG_FLAG_MMAP_IO) {
+ res = -EBUSY; /* sfp->res_in_use == 1 */
+ if (dxfer_len > rsv_schp->bufflen)
+ res = -ENOMEM;
+ mutex_unlock(&sfp->f_mutex);
+ return res;
+ } else {
res = sg_build_indirect(req_schp, sfp, dxfer_len);
- if (res)
+ if (res) {
+ mutex_unlock(&sfp->f_mutex);
return res;
+ }
}
+ mutex_unlock(&sfp->f_mutex);
md->pages = req_schp->pages;
md->page_order = req_schp->page_order;
@@ -1753,6 +1788,10 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
return res;
iov_iter_truncate(&i, hp->dxfer_len);
+ if (!iov_iter_count(&i)) {
+ kfree(iov);
+ return -EINVAL;
+ }
res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
kfree(iov);
@@ -2016,8 +2055,9 @@ sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
req_schp->pages = NULL;
req_schp->page_order = 0;
req_schp->sglist_len = 0;
- sfp->save_scat_len = 0;
srp->res_used = 0;
+ /* Called without mutex lock to avoid deadlock */
+ sfp->res_in_use = 0;
}
static Sg_request *
@@ -2027,7 +2067,7 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id)
unsigned long iflags;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
- for (resp = sfp->headrp; resp; resp = resp->nextrp) {
+ list_for_each_entry(resp, &sfp->rq_list, entry) {
/* look for requests that are ready + not SG_IO owned */
if ((1 == resp->done) && (!resp->sg_io_owned) &&
((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
@@ -2045,70 +2085,45 @@ sg_add_request(Sg_fd * sfp)
{
int k;
unsigned long iflags;
- Sg_request *resp;
Sg_request *rp = sfp->req_arr;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
- resp = sfp->headrp;
- if (!resp) {
- memset(rp, 0, sizeof (Sg_request));
- rp->parentfp = sfp;
- resp = rp;
- sfp->headrp = resp;
- } else {
- if (0 == sfp->cmd_q)
- resp = NULL; /* command queuing disallowed */
- else {
- for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
- if (!rp->parentfp)
- break;
- }
- if (k < SG_MAX_QUEUE) {
- memset(rp, 0, sizeof (Sg_request));
- rp->parentfp = sfp;
- while (resp->nextrp)
- resp = resp->nextrp;
- resp->nextrp = rp;
- resp = rp;
- } else
- resp = NULL;
+ if (!list_empty(&sfp->rq_list)) {
+ if (!sfp->cmd_q)
+ goto out_unlock;
+
+ for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
+ if (!rp->parentfp)
+ break;
}
+ if (k >= SG_MAX_QUEUE)
+ goto out_unlock;
}
- if (resp) {
- resp->nextrp = NULL;
- resp->header.duration = jiffies_to_msecs(jiffies);
- }
+ memset(rp, 0, sizeof (Sg_request));
+ rp->parentfp = sfp;
+ rp->header.duration = jiffies_to_msecs(jiffies);
+ list_add_tail(&rp->entry, &sfp->rq_list);
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return resp;
+ return rp;
+out_unlock:
+ write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return NULL;
}
/* Return of 1 for found; 0 for not found */
static int
sg_remove_request(Sg_fd * sfp, Sg_request * srp)
{
- Sg_request *prev_rp;
- Sg_request *rp;
unsigned long iflags;
int res = 0;
- if ((!sfp) || (!srp) || (!sfp->headrp))
+ if (!sfp || !srp || list_empty(&sfp->rq_list))
return res;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
- prev_rp = sfp->headrp;
- if (srp == prev_rp) {
- sfp->headrp = prev_rp->nextrp;
- prev_rp->parentfp = NULL;
+ if (!list_empty(&srp->entry)) {
+ list_del(&srp->entry);
+ srp->parentfp = NULL;
res = 1;
- } else {
- while ((rp = prev_rp->nextrp)) {
- if (srp == rp) {
- prev_rp->nextrp = rp->nextrp;
- rp->parentfp = NULL;
- res = 1;
- break;
- }
- prev_rp = rp;
- }
}
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
return res;
@@ -2127,8 +2142,9 @@ sg_add_sfp(Sg_device * sdp)
init_waitqueue_head(&sfp->read_wait);
rwlock_init(&sfp->rq_list_lock);
-
+ INIT_LIST_HEAD(&sfp->rq_list);
kref_init(&sfp->f_ref);
+ mutex_init(&sfp->f_mutex);
sfp->timeout = SG_DEFAULT_TIMEOUT;
sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
sfp->force_packid = SG_DEF_FORCE_PACK_ID;
@@ -2167,10 +2183,13 @@ sg_remove_sfp_usercontext(struct work_struct *work)
{
struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
struct sg_device *sdp = sfp->parentdp;
+ Sg_request *srp;
/* Cleanup any responses which were never read(). */
- while (sfp->headrp)
- sg_finish_rem_req(sfp->headrp);
+ while (!list_empty(&sfp->rq_list)) {
+ srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
+ sg_finish_rem_req(srp);
+ }
if (sfp->reserve.bufflen > 0) {
SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
@@ -2204,20 +2223,6 @@ sg_remove_sfp(struct kref *kref)
schedule_work(&sfp->ew.work);
}
-static int
-sg_res_in_use(Sg_fd * sfp)
-{
- const Sg_request *srp;
- unsigned long iflags;
-
- read_lock_irqsave(&sfp->rq_list_lock, iflags);
- for (srp = sfp->headrp; srp; srp = srp->nextrp)
- if (srp->res_used)
- break;
- read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return srp ? 1 : 0;
-}
-
#ifdef CONFIG_SCSI_PROC_FS
static int
sg_idr_max_id(int id, void *p, void *data)
@@ -2587,7 +2592,7 @@ static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
/* must be called while holding sg_index_lock */
static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
{
- int k, m, new_interface, blen, usg;
+ int k, new_interface, blen, usg;
Sg_request *srp;
Sg_fd *fp;
const sg_io_hdr_t *hp;
@@ -2607,13 +2612,11 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
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);
- for (m = 0, srp = fp->headrp;
- srp != NULL;
- ++m, srp = srp->nextrp) {
+ list_for_each_entry(srp, &fp->rq_list, entry) {
hp = &srp->header;
new_interface = (hp->interface_id == '\0') ? 0 : 1;
if (srp->res_used) {
- if (new_interface &&
+ if (new_interface &&
(SG_FLAG_MMAP_IO & hp->flags))
cp = " mmap>> ";
else
@@ -2644,7 +2647,7 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
(int) srp->data.cmd_opcode);
}
- if (0 == m)
+ if (list_empty(&fp->rq_list))
seq_puts(s, " No requests active\n");
read_unlock(&fp->rq_list_lock);
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-05 03:12:21 +0000