* [PATCH v2 1/2] nbd: add support for feature negotiation
2011-09-08 7:44 [PATCH v2 0/2] nbd: add support for DISCARD Paolo Bonzini
@ 2011-09-08 7:44 ` Paolo Bonzini
2011-09-08 7:44 ` [PATCH v2 2/2] nbd: map DISCARD requests to a new nbd request type Paolo Bonzini
1 sibling, 0 replies; 5+ messages in thread
From: Paolo Bonzini @ 2011-09-08 7:44 UTC (permalink / raw)
To: linux-kernel; +Cc: Paul Clements, nbd-general
Add a IOCTL to negotiate features between the server and the kernel
module, with mediation from the userspace client. Features are stored
in the pre-existing (but so far never written to) flags field; bits for
the flags field are adjusted to actually match the network protocol.
Also, zero out the flags when NBD_DO_IT completes.
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: <nbd-general@lists.sf.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
drivers/block/nbd.c | 10 +++++++++-
include/linux/nbd.h | 28 ++++++++++++++--------------
2 files changed, 23 insertions(+), 15 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index be23aec..c4fe9c8 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -85,6 +85,7 @@ static const char *ioctl_cmd_to_ascii(int cmd)
case NBD_PRINT_DEBUG: return "print-debug";
case NBD_SET_SIZE_BLOCKS: return "set-size-blocks";
case NBD_DISCONNECT: return "disconnect";
+ case NBD_SET_FLAGS: return "set-flags";
case BLKROSET: return "set-read-only";
case BLKFLSBUF: return "flush-buffer-cache";
}
@@ -453,7 +453,7 @@ static void nbd_handle_req(struct nbd_device *lo, struct request *req)
nbd_cmd(req) = NBD_CMD_READ;
if (rq_data_dir(req) == WRITE) {
nbd_cmd(req) = NBD_CMD_WRITE;
- if (lo->flags & NBD_READ_ONLY) {
+ if (lo->flags & NBD_FLAG_READ_ONLY) {
printk(KERN_ERR "%s: Write on read-only\n",
lo->disk->disk_name);
goto error_out;
@@ -634,6 +635,12 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
lo->xmit_timeout = arg * HZ;
return 0;
+ case NBD_SET_FLAGS:
+ if (((u64) arg) & (-1ULL << 32))
+ return -EINVAL;
+ lo->flags = arg;
+ return 0;
+
case NBD_SET_SIZE_BLOCKS:
lo->bytesize = ((u64) arg) * lo->blksize;
bdev->bd_inode->i_size = lo->bytesize;
@@ -672,6 +679,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
if (file)
fput(file);
+ lo->flags = 0;
lo->bytesize = 0;
bdev->bd_inode->i_size = 0;
set_capacity(lo->disk, 0);
diff --git a/include/linux/nbd.h b/include/linux/nbd.h
index 0582054..926f19d 100644
--- a/include/linux/nbd.h
+++ b/include/linux/nbd.h
@@ -17,16 +17,20 @@
#include <linux/types.h>
-#define NBD_SET_SOCK _IO( 0xab, 0 )
-#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
-#define NBD_SET_SIZE _IO( 0xab, 2 )
-#define NBD_DO_IT _IO( 0xab, 3 )
-#define NBD_CLEAR_SOCK _IO( 0xab, 4 )
-#define NBD_CLEAR_QUE _IO( 0xab, 5 )
-#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
-#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
-#define NBD_DISCONNECT _IO( 0xab, 8 )
-#define NBD_SET_TIMEOUT _IO( 0xab, 9 )
+#define NBD_SET_SOCK _IO(0xab, 0)
+#define NBD_SET_BLKSIZE _IO(0xab, 1)
+#define NBD_SET_SIZE _IO(0xab, 2)
+#define NBD_DO_IT _IO(0xab, 3)
+#define NBD_CLEAR_SOCK _IO(0xab, 4)
+#define NBD_CLEAR_QUE _IO(0xab, 5)
+#define NBD_PRINT_DEBUG _IO(0xab, 6)
+#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
+#define NBD_DISCONNECT _IO(0xab, 8)
+#define NBD_SET_TIMEOUT _IO(0xab, 9)
+#define NBD_SET_FLAGS _IO(0xab, 10)
+
+/* values for flags field */
+#define NBD_FLAG_READ_ONLY (1 << 1)
enum {
NBD_CMD_READ = 0,
@@ -42,10 +46,6 @@ enum {
#include <linux/wait.h>
#include <linux/mutex.h>
-/* values for flags field */
-#define NBD_READ_ONLY 0x0001
-#define NBD_WRITE_NOCHK 0x0002
-
struct request;
struct nbd_device {
--
1.7.6
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2 2/2] nbd: map DISCARD requests to a new nbd request type
2011-09-08 7:44 [PATCH v2 0/2] nbd: add support for DISCARD Paolo Bonzini
2011-09-08 7:44 ` [PATCH v2 1/2] nbd: add support for feature negotiation Paolo Bonzini
@ 2011-09-08 7:44 ` Paolo Bonzini
2011-09-08 8:42 ` [Nbd] " Alex Bligh
1 sibling, 1 reply; 5+ messages in thread
From: Paolo Bonzini @ 2011-09-08 7:44 UTC (permalink / raw)
To: linux-kernel; +Cc: Paul Clements, nbd-general
When the feature is enabled, set QUEUE_FLAG_DISCARD and transmit those as
NBD_CMD_TRIM requests.
I used "trim" instead of "discard" to avoid confusion with the existing
NBD_CMD_DISC that is used for disconnect.
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: <nbd-general@lists.sf.net>
Reviewed-by: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
This patch is the same as in v1.
drivers/block/nbd.c | 14 +++++++++++++-
include/linux/nbd.h | 4 +++-
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index c4fe9c8..71ebaab 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -98,6 +98,7 @@ static const char *nbdcmd_to_ascii(int cmd)
case NBD_CMD_READ: return "read";
case NBD_CMD_WRITE: return "write";
case NBD_CMD_DISC: return "disconnect";
+ case NBD_CMD_TRIM: return "trim (discard)";
}
return "invalid";
}
@@ -453,12 +453,16 @@ static void nbd_handle_req(struct nbd_device *lo, struct request *req)
nbd_cmd(req) = NBD_CMD_READ;
if (rq_data_dir(req) == WRITE) {
- nbd_cmd(req) = NBD_CMD_WRITE;
if (lo->flags & NBD_FLAG_READ_ONLY) {
printk(KERN_ERR "%s: Write on read-only\n",
lo->disk->disk_name);
goto error_out;
}
+ if ((req->cmd_flags & REQ_DISCARD)) {
+ WARN_ON(!(lo->flags & NBD_FLAG_HAS_TRIM));
+ nbd_cmd(req) = NBD_CMD_TRIM;
+ } else
+ nbd_cmd(req) = NBD_CMD_WRITE;
}
req->errors = 0;
@@ -659,6 +664,9 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
return -EINVAL;
mutex_unlock(&lo->tx_lock);
+ if (lo->flags & NBD_FLAG_HAS_TRIM)
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
+ lo->disk->queue);
thread = kthread_create(nbd_thread, lo, lo->disk->disk_name);
if (IS_ERR(thread)) {
@@ -677,6 +685,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
lo->file = NULL;
nbd_clear_que(lo);
printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
+ queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, lo->disk->queue);
if (file)
fput(file);
lo->flags = 0;
@@ -796,6 +805,9 @@ static int __init nbd_init(void)
* Tell the block layer that we are not a rotational device
*/
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
+ disk->queue->limits.discard_granularity = 512;
+ disk->queue->limits.max_discard_sectors = UINT_MAX;
+ disk->queue->limits.discard_zeroes_data = 0;
}
if (register_blkdev(NBD_MAJOR, "nbd")) {
diff --git a/include/linux/nbd.h b/include/linux/nbd.h
index 926f19d..7048463 100644
--- a/include/linux/nbd.h
+++ b/include/linux/nbd.h
@@ -33,11 +33,13 @@
/* values for flags field */
#define NBD_FLAG_READ_ONLY (1 << 1)
+#define NBD_FLAG_HAS_TRIM (1 << 2)
enum {
NBD_CMD_READ = 0,
NBD_CMD_WRITE = 1,
- NBD_CMD_DISC = 2
+ NBD_CMD_DISC = 2,
+ NBD_CMD_TRIM = 3
};
#define nbd_cmd(req) ((req)->cmd[0])
--
1.7.6
^ permalink raw reply [flat|nested] 5+ messages in thread