[SCSI] sg: remove the own list management for struct sg_fd

This replaces the own list management for struct sg_fd with the
standard list_head structure.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
FUJITA Tomonori 2009-02-16 13:26:53 +09:00 committed by James Bottomley
parent b2ed6c69aa
commit 3442f802a8
1 changed files with 14 additions and 36 deletions

View File

@ -140,7 +140,7 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
} Sg_request; } Sg_request;
typedef struct sg_fd { /* holds the state of a file descriptor */ typedef struct sg_fd { /* holds the state of a file descriptor */
struct sg_fd *nextfp; /* NULL when last opened fd on this device */ struct list_head sfd_siblings;
struct sg_device *parentdp; /* owning device */ struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */ wait_queue_head_t read_wait; /* queue read until command done */
rwlock_t rq_list_lock; /* protect access to list in req_arr */ rwlock_t rq_list_lock; /* protect access to list in req_arr */
@ -167,7 +167,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */ wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */
int sg_tablesize; /* adapter's max scatter-gather table size */ int sg_tablesize; /* adapter's max scatter-gather table size */
u32 index; /* device index number */ u32 index; /* device index number */
Sg_fd *headfp; /* first open fd belonging to this device */ struct list_head sfds;
volatile char detached; /* 0->attached, 1->detached pending removal */ volatile char detached; /* 0->attached, 1->detached pending removal */
volatile char exclude; /* opened for exclusive access */ volatile char exclude; /* opened for exclusive access */
char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */ char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
@ -258,13 +258,13 @@ sg_open(struct inode *inode, struct file *filp)
retval = -EPERM; /* Can't lock it with read only access */ retval = -EPERM; /* Can't lock it with read only access */
goto error_out; goto error_out;
} }
if (sdp->headfp && (flags & O_NONBLOCK)) { if (!list_empty(&sdp->sfds) && (flags & O_NONBLOCK)) {
retval = -EBUSY; retval = -EBUSY;
goto error_out; goto error_out;
} }
res = 0; res = 0;
__wait_event_interruptible(sdp->o_excl_wait, __wait_event_interruptible(sdp->o_excl_wait,
((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res); ((!list_empty(&sdp->sfds) || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
if (res) { if (res) {
retval = res; /* -ERESTARTSYS because signal hit process */ retval = res; /* -ERESTARTSYS because signal hit process */
goto error_out; goto error_out;
@ -286,7 +286,7 @@ sg_open(struct inode *inode, struct file *filp)
retval = -ENODEV; retval = -ENODEV;
goto error_out; goto error_out;
} }
if (!sdp->headfp) { /* no existing opens on this device */ if (list_empty(&sdp->sfds)) { /* no existing opens on this device */
sdp->sgdebug = 0; sdp->sgdebug = 0;
q = sdp->device->request_queue; q = sdp->device->request_queue;
sdp->sg_tablesize = min(q->max_hw_segments, sdp->sg_tablesize = min(q->max_hw_segments,
@ -1375,6 +1375,7 @@ static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
disk->first_minor = k; disk->first_minor = k;
sdp->disk = disk; sdp->disk = disk;
sdp->device = scsidp; sdp->device = scsidp;
INIT_LIST_HEAD(&sdp->sfds);
init_waitqueue_head(&sdp->o_excl_wait); init_waitqueue_head(&sdp->o_excl_wait);
sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments); sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
sdp->index = k; sdp->index = k;
@ -1517,7 +1518,7 @@ static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
/* Need a write lock to set sdp->detached. */ /* Need a write lock to set sdp->detached. */
write_lock_irqsave(&sg_index_lock, iflags); write_lock_irqsave(&sg_index_lock, iflags);
sdp->detached = 1; sdp->detached = 1;
for (sfp = sdp->headfp; sfp; sfp = sfp->nextfp) { list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
wake_up_interruptible(&sfp->read_wait); wake_up_interruptible(&sfp->read_wait);
kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP); kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
} }
@ -2024,14 +2025,7 @@ sg_add_sfp(Sg_device * sdp, int dev)
sfp->keep_orphan = SG_DEF_KEEP_ORPHAN; sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
sfp->parentdp = sdp; sfp->parentdp = sdp;
write_lock_irqsave(&sg_index_lock, iflags); write_lock_irqsave(&sg_index_lock, iflags);
if (!sdp->headfp) list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
sdp->headfp = sfp;
else { /* add to tail of existing list */
Sg_fd *pfp = sdp->headfp;
while (pfp->nextfp)
pfp = pfp->nextfp;
pfp->nextfp = sfp;
}
write_unlock_irqrestore(&sg_index_lock, iflags); write_unlock_irqrestore(&sg_index_lock, iflags);
SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp)); SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
if (unlikely(sg_big_buff != def_reserved_size)) if (unlikely(sg_big_buff != def_reserved_size))
@ -2080,28 +2074,10 @@ static void sg_remove_sfp(struct kref *kref)
{ {
struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref); struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
struct sg_device *sdp = sfp->parentdp; struct sg_device *sdp = sfp->parentdp;
Sg_fd *fp;
Sg_fd *prev_fp;
unsigned long iflags; unsigned long iflags;
/* CAUTION! Note that sfp can still be found by walking sdp->headfp
* even though the refcount is now 0. Therefore, unlink sfp from
* sdp->headfp BEFORE doing any other cleanup.
*/
write_lock_irqsave(&sg_index_lock, iflags); write_lock_irqsave(&sg_index_lock, iflags);
prev_fp = sdp->headfp; list_del(&sfp->sfd_siblings);
if (sfp == prev_fp)
sdp->headfp = prev_fp->nextfp;
else {
while ((fp = prev_fp->nextfp)) {
if (sfp == fp) {
prev_fp->nextfp = fp->nextfp;
break;
}
prev_fp = fp;
}
}
write_unlock_irqrestore(&sg_index_lock, iflags); write_unlock_irqrestore(&sg_index_lock, iflags);
wake_up_interruptible(&sdp->o_excl_wait); wake_up_interruptible(&sdp->o_excl_wait);
@ -2486,10 +2462,12 @@ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
const char * cp; const char * cp;
unsigned int ms; unsigned int ms;
for (k = 0, fp = sdp->headfp; fp != NULL; ++k, fp = fp->nextfp) { k = 0;
list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
k++;
read_lock(&fp->rq_list_lock); /* irqs already disabled */ read_lock(&fp->rq_list_lock); /* irqs already disabled */
seq_printf(s, " FD(%d): timeout=%dms bufflen=%d " seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
"(res)sgat=%d low_dma=%d\n", k + 1, "(res)sgat=%d low_dma=%d\n", k,
jiffies_to_msecs(fp->timeout), jiffies_to_msecs(fp->timeout),
fp->reserve.bufflen, fp->reserve.bufflen,
(int) fp->reserve.k_use_sg, (int) fp->reserve.k_use_sg,
@ -2559,7 +2537,7 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
read_lock_irqsave(&sg_index_lock, iflags); read_lock_irqsave(&sg_index_lock, iflags);
sdp = it ? sg_lookup_dev(it->index) : NULL; sdp = it ? sg_lookup_dev(it->index) : NULL;
if (sdp && sdp->headfp) { if (sdp && !list_empty(&sdp->sfds)) {
struct scsi_device *scsidp = sdp->device; struct scsi_device *scsidp = sdp->device;
seq_printf(s, " >>> device=%s ", sdp->disk->disk_name); seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);