static void sg_remove(struct device *, struct class_interface *);
static DEFINE_MUTEX(sg_mutex);
+static DEFINE_SPINLOCK(sg_open_exclusive_lock);
static DEFINE_IDR(sg_index_idr);
static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
char orphan; /* 1 -> drop on sight, 0 -> normal */
char sg_io_owned; /* 1 -> packet belongs to SG_IO */
- volatile char done; /* 0->before bh, 1->before read, 2->read */
+ /* done protected by rq_list_lock */
+ char done; /* 0->before bh, 1->before read, 2->read */
struct request *rq;
struct bio *bio;
struct execute_work ew;
} Sg_request;
typedef struct sg_fd { /* holds the state of a file descriptor */
+ /* sfd_siblings is protected by sg_index_lock */
struct list_head sfd_siblings;
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
char low_dma; /* as in parent but possibly overridden to 1 */
char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
- volatile char closed; /* 1 -> fd closed but request(s) outstanding */
char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
char next_cmd_len; /* 0 -> automatic (def), >0 -> use on next write() */
char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */
int sg_tablesize; /* adapter's max scatter-gather table size */
u32 index; /* device index number */
+ /* sfds is protected by sg_index_lock */
struct list_head sfds;
volatile char detached; /* 0->attached, 1->detached pending removal */
- volatile char exclude; /* opened for exclusive access */
+ /* exclude protected by sg_open_exclusive_lock */
+ char exclude; /* opened for exclusive access */
char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
struct gendisk *disk;
struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
}
+static int get_exclude(Sg_device *sdp)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&sg_open_exclusive_lock, flags);
+ ret = sdp->exclude;
+ spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
+ return ret;
+}
+
+static int set_exclude(Sg_device *sdp, char val)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sg_open_exclusive_lock, flags);
+ sdp->exclude = val;
+ spin_unlock_irqrestore(&sg_open_exclusive_lock, flags);
+ return val;
+}
+
+static int sfds_list_empty(Sg_device *sdp)
+{
+ unsigned long flags;
+ int ret;
+
+ read_lock_irqsave(&sg_index_lock, flags);
+ ret = list_empty(&sdp->sfds);
+ read_unlock_irqrestore(&sg_index_lock, flags);
+ return ret;
+}
+
static int
sg_open(struct inode *inode, struct file *filp)
{
retval = -EPERM; /* Can't lock it with read only access */
goto error_out;
}
- if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
+ if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) {
retval = -EBUSY;
goto error_out;
}
- res = 0;
- __wait_event_interruptible(sdp->o_excl_wait,
- ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
+ res = wait_event_interruptible(sdp->o_excl_wait,
+ ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1)));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
}
- } else if (sdp->exclude) { /* some other fd has an exclusive lock on dev */
+ } else if (get_exclude(sdp)) { /* some other fd has an exclusive lock on dev */
if (flags & O_NONBLOCK) {
retval = -EBUSY;
goto error_out;
}
- res = 0;
- __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
- res);
+ res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp));
if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out;
retval = -ENODEV;
goto error_out;
}
- if (list_empty(&sdp->sfds)) { /* no existing opens on this device */
+ if (sfds_list_empty(sdp)) { /* no existing opens on this device */
sdp->sgdebug = 0;
q = sdp->device->request_queue;
sdp->sg_tablesize = queue_max_segments(q);
filp->private_data = sfp;
else {
if (flags & O_EXCL) {
- sdp->exclude = 0; /* undo if error */
+ set_exclude(sdp, 0); /* undo if error */
wake_up_interruptible(&sdp->o_excl_wait);
}
retval = -ENOMEM;
return -ENXIO;
SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
- sfp->closed = 1;
-
- sdp->exclude = 0;
+ set_exclude(sdp, 0);
wake_up_interruptible(&sdp->o_excl_wait);
scsi_autopm_put_device(sdp->device);
retval = -EAGAIN;
goto free_old_hdr;
}
- while (1) {
- retval = 0; /* following macro beats race condition */
- __wait_event_interruptible(sfp->read_wait,
- (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;
-
+ retval = wait_event_interruptible(sfp->read_wait,
+ (sdp->detached ||
+ (srp = sg_get_rq_mark(sfp, req_pack_id))));
+ if (sdp->detached) {
+ retval = -ENODEV;
+ goto free_old_hdr;
+ }
+ if (retval) {
/* -ERESTARTSYS as signal hit process */
goto free_old_hdr;
}
return 0;
}
+static int srp_done(Sg_fd *sfp, Sg_request *srp)
+{
+ unsigned long flags;
+ int ret;
+
+ read_lock_irqsave(&sfp->rq_list_lock, flags);
+ ret = srp->done;
+ read_unlock_irqrestore(&sfp->rq_list_lock, flags);
+ return ret;
+}
+
static int
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
switch (cmd_in) {
case SG_IO:
- {
- int blocking = 1; /* ignore O_NONBLOCK flag */
-
- if (sdp->detached)
- return -ENODEV;
- if (!scsi_block_when_processing_errors(sdp->device))
- 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,
- blocking, read_only, 1, &srp);
- if (result < 0)
- return result;
- while (1) {
- result = 0; /* following macro to beat race condition */
- __wait_event_interruptible(sfp->read_wait,
- (srp->done || sdp->detached),
- result);
- if (sdp->detached)
- return -ENODEV;
- write_lock_irq(&sfp->rq_list_lock);
- if (srp->done) {
- srp->done = 2;
- write_unlock_irq(&sfp->rq_list_lock);
- break;
- }
- srp->orphan = 1;
- write_unlock_irq(&sfp->rq_list_lock);
- return result; /* -ERESTARTSYS because signal hit process */
- }
+ if (sdp->detached)
+ return -ENODEV;
+ if (!scsi_block_when_processing_errors(sdp->device))
+ 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);
+ if (result < 0)
+ return result;
+ result = wait_event_interruptible(sfp->read_wait,
+ (srp_done(sfp, srp) || sdp->detached));
+ if (sdp->detached)
+ return -ENODEV;
+ write_lock_irq(&sfp->rq_list_lock);
+ if (srp->done) {
+ srp->done = 2;
+ write_unlock_irq(&sfp->rq_list_lock);
result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
return (result < 0) ? result : 0;
}
+ srp->orphan = 1;
+ write_unlock_irq(&sfp->rq_list_lock);
+ return result; /* -ERESTARTSYS because signal hit process */
case SG_SET_TIMEOUT:
result = get_user(val, ip);
if (result)
int count = 0;
unsigned long iflags;
- if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
- || sfp->closed)
+ sfp = filp->private_data;
+ if (!sfp)
+ return POLLERR;
+ sdp = sfp->parentdp;
+ if (!sdp)
return POLLERR;
poll_wait(filp, &sfp->read_wait, wait);
read_lock_irqsave(&sfp->rq_list_lock, iflags);
fp->reserve.bufflen,
(int) fp->reserve.k_use_sg,
(int) fp->low_dma);
- seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
+ 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, (int) fp->closed);
+ (int) fp->keep_orphan);
for (m = 0, srp = fp->headrp;
srp != NULL;
++m, srp = srp->nextrp) {
scsidp->lun,
scsidp->host->hostt->emulated);
seq_printf(s, " sg_tablesize=%d excl=%d\n",
- sdp->sg_tablesize, sdp->exclude);
+ sdp->sg_tablesize, get_exclude(sdp));
sg_proc_debug_helper(s, sdp);
}
read_unlock_irqrestore(&sg_index_lock, iflags);
projects / ~andy / linux / blobdiff