bsg: address various review comments
This address most of the comments made by Andrew. The two remaining
are conversion to idr, and dynamic major.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/bsg.c b/block/bsg.c
index 576933f..26a9372 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -33,7 +33,7 @@
#include <scsi/scsi_driver.h>
#include <scsi/sg.h>
-static char bsg_version[] = "block layer sg (bsg) 0.4";
+const static char bsg_version[] = "block layer sg (bsg) 0.4";
struct bsg_device {
request_queue_t *queue;
@@ -68,8 +68,6 @@
#define dprintk(fmt, args...)
#endif
-#define list_entry_bc(entry) list_entry((entry), struct bsg_command, list)
-
/*
* just for testing
*/
@@ -78,9 +76,9 @@
static DEFINE_MUTEX(bsg_mutex);
static int bsg_device_nr, bsg_minor_idx;
-#define BSG_LIST_SIZE (8)
-#define bsg_list_idx(minor) ((minor) & (BSG_LIST_SIZE - 1))
-static struct hlist_head bsg_device_list[BSG_LIST_SIZE];
+#define BSG_LIST_ARRAY_SIZE 8
+#define bsg_list_idx(minor) ((minor) & (BSG_LIST_ARRAY_SIZE - 1))
+static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
static struct class *bsg_class;
static LIST_HEAD(bsg_class_list);
@@ -128,7 +126,7 @@
bd->queued_cmds++;
spin_unlock_irq(&bd->lock);
- bc = kmem_cache_alloc(bsg_cmd_cachep, GFP_USER);
+ bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
if (unlikely(!bc)) {
spin_lock_irq(&bd->lock);
bd->queued_cmds--;
@@ -136,7 +134,6 @@
goto out;
}
- memset(bc, 0, sizeof(*bc));
bc->bd = bd;
INIT_LIST_HEAD(&bc->list);
dprintk("%s: returning free cmd %p\n", bd->name, bc);
@@ -147,21 +144,11 @@
}
static inline void
-bsg_del_done_cmd(struct bsg_device *bd, struct bsg_command *bc)
-{
- bd->done_cmds--;
- list_del(&bc->list);
-}
-
-static inline void
bsg_add_done_cmd(struct bsg_device *bd, struct bsg_command *bc)
{
- bd->done_cmds++;
- list_add_tail(&bc->list, &bd->done_list);
- wake_up(&bd->wq_done);
}
-static inline int bsg_io_schedule(struct bsg_device *bd, int state)
+static int bsg_io_schedule(struct bsg_device *bd)
{
DEFINE_WAIT(wait);
int ret = 0;
@@ -186,14 +173,11 @@
goto unlock;
}
- prepare_to_wait(&bd->wq_done, &wait, state);
+ prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&bd->lock);
io_schedule();
finish_wait(&bd->wq_done, &wait);
- if ((state == TASK_INTERRUPTIBLE) && signal_pending(current))
- ret = -ERESTARTSYS;
-
return ret;
unlock:
spin_unlock_irq(&bd->lock);
@@ -272,7 +256,7 @@
{
request_queue_t *q = bd->queue;
struct request *rq, *next_rq = NULL;
- int ret, rw = 0; /* shut up gcc */
+ int ret, rw;
unsigned int dxfer_len;
void *dxferp = NULL;
@@ -354,9 +338,11 @@
bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
spin_lock_irqsave(&bd->lock, flags);
- list_del(&bc->list);
- bsg_add_done_cmd(bd, bc);
+ list_move_tail(&bc->list, &bd->done_list);
+ bd->done_cmds++;
spin_unlock_irqrestore(&bd->lock, flags);
+
+ wake_up(&bd->wq_done);
}
/*
@@ -387,14 +373,15 @@
blk_execute_rq_nowait(q, NULL, rq, 1, bsg_rq_end_io);
}
-static inline struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
+static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
{
struct bsg_command *bc = NULL;
spin_lock_irq(&bd->lock);
if (bd->done_cmds) {
- bc = list_entry_bc(bd->done_list.next);
- bsg_del_done_cmd(bd, bc);
+ bc = list_entry(bd->done_list.next, struct bsg_command, list);
+ list_del(&bc->list);
+ bd->done_cmds--;
}
spin_unlock_irq(&bd->lock);
@@ -450,8 +437,8 @@
hdr->response_len = 0;
if (rq->sense_len && hdr->response) {
- int len = min((unsigned int) hdr->max_response_len,
- rq->sense_len);
+ int len = min_t(unsigned int, hdr->max_response_len,
+ rq->sense_len);
ret = copy_to_user((void*)(unsigned long)hdr->response,
rq->sense, len);
@@ -486,7 +473,7 @@
*/
ret = 0;
do {
- ret = bsg_io_schedule(bd, TASK_UNINTERRUPTIBLE);
+ ret = bsg_io_schedule(bd);
/*
* look for -ENODATA specifically -- we'll sometimes get
* -ERESTARTSYS when we've taken a signal, but we can't
@@ -523,7 +510,7 @@
return ret;
}
-static ssize_t
+static int
__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
const struct iovec *iov, ssize_t *bytes_read)
{
@@ -550,7 +537,7 @@
ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
bc->bidi_bio);
- if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))
+ if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
ret = -EFAULT;
bsg_free_command(bc);
@@ -582,6 +569,9 @@
clear_bit(BSG_F_WRITE_PERM, &bd->flags);
}
+/*
+ * Check if the error is a "real" error that we should return.
+ */
static inline int err_block_err(int ret)
{
if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
@@ -610,8 +600,8 @@
return bytes_read;
}
-static ssize_t __bsg_write(struct bsg_device *bd, const char __user *buf,
- size_t count, ssize_t *bytes_read)
+static int __bsg_write(struct bsg_device *bd, const char __user *buf,
+ size_t count, ssize_t *bytes_written)
{
struct bsg_command *bc;
struct request *rq;
@@ -655,7 +645,7 @@
rq = NULL;
nr_commands--;
buf += sizeof(struct sg_io_v4);
- *bytes_read += sizeof(struct sg_io_v4);
+ *bytes_written += sizeof(struct sg_io_v4);
}
if (bc)
@@ -668,7 +658,7 @@
bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
struct bsg_device *bd = file->private_data;
- ssize_t bytes_read;
+ ssize_t bytes_written;
int ret;
dprintk("%s: write %Zd bytes\n", bd->name, count);
@@ -676,18 +666,18 @@
bsg_set_block(bd, file);
bsg_set_write_perm(bd, file);
- bytes_read = 0;
- ret = __bsg_write(bd, buf, count, &bytes_read);
- *ppos = bytes_read;
+ bytes_written = 0;
+ ret = __bsg_write(bd, buf, count, &bytes_written);
+ *ppos = bytes_written;
/*
* return bytes written on non-fatal errors
*/
- if (!bytes_read || (bytes_read && err_block_err(ret)))
- bytes_read = ret;
+ if (!bytes_written || (bytes_written && err_block_err(ret)))
+ bytes_written = ret;
- dprintk("%s: returning %Zd\n", bd->name, bytes_read);
- return bytes_read;
+ dprintk("%s: returning %Zd\n", bd->name, bytes_written);
+ return bytes_written;
}
static struct bsg_device *bsg_alloc_device(void)
@@ -746,7 +736,7 @@
struct request_queue *rq,
struct file *file)
{
- struct bsg_device *bd = NULL;
+ struct bsg_device *bd;
#ifdef BSG_DEBUG
unsigned char buf[32];
#endif
@@ -762,7 +752,8 @@
atomic_set(&bd->ref_count, 1);
bd->minor = iminor(inode);
mutex_lock(&bsg_mutex);
- hlist_add_head(&bd->dev_list, &bsg_device_list[bsg_list_idx(bd->minor)]);
+ hlist_add_head(&bd->dev_list,
+ &bsg_device_list[bd->minor & (BSG_LIST_ARRAY_SIZE - 1)]);
strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1);
dprintk("bound to <%s>, max queue %d\n",
@@ -774,12 +765,13 @@
static struct bsg_device *__bsg_get_device(int minor)
{
- struct hlist_head *list = &bsg_device_list[bsg_list_idx(minor)];
+ struct hlist_head *list;
struct bsg_device *bd = NULL;
struct hlist_node *entry;
mutex_lock(&bsg_mutex);
+ list = &bsg_device_list[minor & (BSG_LIST_ARRAY_SIZE - 1)];
hlist_for_each(entry, list) {
bd = hlist_entry(entry, struct bsg_device, dev_list);
if (bd->minor == minor) {
@@ -858,16 +850,11 @@
return mask;
}
-static int
-bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
- unsigned long arg)
+static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct bsg_device *bd = file->private_data;
int __user *uarg = (int __user *) arg;
- if (!bd)
- return -ENXIO;
-
switch (cmd) {
/*
* our own ioctls
@@ -944,7 +931,7 @@
.poll = bsg_poll,
.open = bsg_open,
.release = bsg_release,
- .ioctl = bsg_ioctl,
+ .unlocked_ioctl = bsg_ioctl,
.owner = THIS_MODULE,
};
@@ -952,8 +939,7 @@
{
struct bsg_class_device *bcd = &q->bsg_dev;
- if (!bcd->class_dev)
- return;
+ WARN_ON(!bcd->class_dev);
mutex_lock(&bsg_mutex);
sysfs_remove_link(&q->kobj, "bsg");
@@ -1069,7 +1055,7 @@
return -ENOMEM;
}
- for (i = 0; i < BSG_LIST_SIZE; i++)
+ for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
INIT_HLIST_HEAD(&bsg_device_list[i]);
bsg_class = class_create(THIS_MODULE, "bsg");