From: Omar Sandoval <osan...@fb.com>
This driver likes to fetch requests from all over the place, so make
queue_rq put requests on a list so that the logic stays the same. Tested
with QEMU.
Signed-off-by: Omar Sandoval <osan...@fb.com>
---
drivers/block/floppy.c | 74 +++++++++++++++++++++++++-----------------
1 file changed, 44 insertions(+), 30 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index acbafd831ea3..eb19125beb90 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -252,13 +252,13 @@ static int allowed_drive_mask = 0x33;
static int irqdma_allocated;
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/blkpg.h>
#include <linux/cdrom.h> /* for the compatibility eject ioctl */
#include <linux/completion.h>
+static LIST_HEAD(floppy_reqs);
static struct request *current_req;
-static void do_fd_request(struct request_queue *q);
static int set_next_request(void);
#ifndef fd_get_dma_residue
@@ -414,10 +414,10 @@ static struct floppy_drive_struct drive_state[N_DRIVE];
static struct floppy_write_errors write_errors[N_DRIVE];
static struct timer_list motor_off_timer[N_DRIVE];
static struct gendisk *disks[N_DRIVE];
+static struct blk_mq_tag_set tag_sets[N_DRIVE];
static struct block_device *opened_bdev[N_DRIVE];
static DEFINE_MUTEX(open_lock);
static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;
-static int fdc_queue;
/*
* This struct defines the different floppy types.
@@ -2218,8 +2218,9 @@ static void floppy_end_request(struct request *req,
blk_status_t error)
nr_bytes = blk_rq_bytes(req);
else
nr_bytes = current_count_sectors << 9;
- if (__blk_end_request(req, error, nr_bytes))
+ if (blk_update_request(req, error, nr_bytes))
return;
+ __blk_mq_end_request(req, error);
/* We're done with the request */
floppy_off(drive);
@@ -2799,27 +2800,14 @@ static int make_raw_rw_request(void)
return 2;
}
-/*
- * Round-robin between our available drives, doing one request from each
- */
static int set_next_request(void)
{
- struct request_queue *q;
- int old_pos = fdc_queue;
-
- do {
- q = disks[fdc_queue]->queue;
- if (++fdc_queue == N_DRIVE)
- fdc_queue = 0;
- if (q) {
- current_req = blk_fetch_request(q);
- if (current_req) {
- current_req->error_count = 0;
- break;
- }
- }
- } while (fdc_queue != old_pos);
-
+ current_req = list_first_entry_or_null(&floppy_reqs, struct request,
+ queuelist);
+ if (current_req) {
+ current_req->error_count = 0;
+ list_del_init(¤t_req->queuelist);
+ }
return current_req != NULL;
}
@@ -2903,29 +2891,38 @@ static void process_fd_request(void)
schedule_bh(redo_fd_request);
}
-static void do_fd_request(struct request_queue *q)
+static blk_status_t floppy_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
{
+ blk_mq_start_request(bd->rq);
+
if (WARN(max_buffer_sectors == 0,
"VFS: %s called on non-open device\n", __func__))
- return;
+ return BLK_STS_IOERR;
if (WARN(atomic_read(&usage_count) == 0,
"warning: usage count=0, current_req=%p sect=%ld flags=%llx\n",
current_req, (long)blk_rq_pos(current_req),
(unsigned long long) current_req->cmd_flags))
- return;
+ return BLK_STS_IOERR;
+
+ spin_lock_irq(&floppy_lock);
+ list_add_tail(&bd->rq->queuelist, &floppy_reqs);
+ spin_unlock_irq(&floppy_lock);
if (test_and_set_bit(0, &fdc_busy)) {
/* fdc busy, this new request will be treated when the
current one is done */
is_alive(__func__, "old request running");
- return;
+ return BLK_STS_OK;
}
+
command_status = FD_COMMAND_NONE;
__reschedule_timeout(MAXTIMEOUT, "fd_request");
set_fdc(0);
process_fd_request();
is_alive(__func__, "");
+ return BLK_STS_OK;
}
static const struct cont_t poll_cont = {
@@ -4488,6 +4485,10 @@ static struct platform_driver floppy_driver = {
},
};
+static const struct blk_mq_ops floppy_mq_ops = {
+ .queue_rq = floppy_queue_rq,
+};
+
static struct platform_device floppy_device[N_DRIVE];
static bool floppy_available(int drive)
@@ -4529,15 +4530,28 @@ static int __init do_floppy_init(void)
return -ENOMEM;
for (drive = 0; drive < N_DRIVE; drive++) {
+ struct blk_mq_tag_set *set;
+
disks[drive] = alloc_disk(1);
if (!disks[drive]) {
err = -ENOMEM;
goto out_put_disk;
}
- disks[drive]->queue = blk_init_queue(do_fd_request,
&floppy_lock);
- if (!disks[drive]->queue) {
- err = -ENOMEM;
+ set = &tag_sets[drive];
+ set->ops = &floppy_mq_ops;
+ set->nr_hw_queues = 1;
+ set->queue_depth = 2;
+ set->numa_node = NUMA_NO_NODE;
+ set->flags = BLK_MQ_F_SHOULD_MERGE;
+ err = blk_mq_alloc_tag_set(set);
+ if (err)
+ goto out_put_disk;
+
+ disks[drive]->queue = blk_mq_init_queue(set);
+ if (IS_ERR(disks[drive]->queue)) {
+ err = PTR_ERR(disks[drive]->queue);
+ disks[drive]->queue = NULL;
goto out_put_disk;
}
--
2.19.1
