On 11/29/2017 05:39 PM, Nikolay Borisov wrote:


On 29.11.2017 06:45, Anand Jain wrote:
Currently device state is being managed by each individual int
variable such as struct btrfs_device::can_discard. Instead of that
declare btrfs_device::dev_state BTRFS_DEV_STATE_CAN_DISCARD and use
the bit operations.

Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
  fs/btrfs/extent-tree.c | 3 ++-
  fs/btrfs/volumes.c     | 6 +++---
  fs/btrfs/volumes.h     | 2 +-
  3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f81d928754e1..ee79f7cdc543 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2155,7 +2155,8 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, 
u64 bytenr,
for (i = 0; i < bbio->num_stripes; i++, stripe++) {
                        u64 bytes;
-                       if (!stripe->dev->can_discard)
+                       if (!test_bit(BTRFS_DEV_STATE_CAN_DISCARD,
+                                               &stripe->dev->dev_state))
                                continue;

Given that we only check for discard support here I can't help but think
do we really need to duplicate the information. We already have struct
block_device in struct btrfs_device, why don't we query for discard
support directly the underlying device, rather than duplicating
information?

 I agree. bdev_get_queue(bdev) and blk_queue_discard(q) are light weight
 too.
 So I shall withdraw this patch and sent the following patch to
 remove can_discard altogether.
   [PATCH] btrfs: drop btrfs_device::can_discard to query directly

Thanks, Anand


ret = btrfs_issue_discard(stripe->dev->bdev,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 75839e07ce10..a9c6486f06f4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -647,7 +647,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices 
*fs_devices,
q = bdev_get_queue(bdev);
        if (blk_queue_discard(q))
-               device->can_discard = 1;
+               set_bit(BTRFS_DEV_STATE_CAN_DISCARD, &device->dev_state);
        if (!blk_queue_nonrot(q))
                fs_devices->rotating = 1;
@@ -2401,7 +2401,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path q = bdev_get_queue(bdev);
        if (blk_queue_discard(q))
-               device->can_discard = 1;
+               set_bit(BTRFS_DEV_STATE_CAN_DISCARD, &device->dev_state);
        set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
        device->generation = trans->transid;
        device->io_width = fs_info->sectorsize;
@@ -2601,7 +2601,7 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info 
*fs_info,
q = bdev_get_queue(bdev);
        if (blk_queue_discard(q))
-               device->can_discard = 1;
+               set_bit(BTRFS_DEV_STATE_CAN_DISCARD, &device->dev_state);
        mutex_lock(&fs_info->fs_devices->device_list_mutex);
        set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
        device->generation = 0;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2fbff6902c8d..85e4b2dcc071 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -50,6 +50,7 @@ struct btrfs_pending_bios {
  #define BTRFS_DEV_STATE_WRITEABLE     (1UL << 1)
  #define BTRFS_DEV_STATE_IN_FS_METADATA        (1UL << 2)
  #define BTRFS_DEV_STATE_MISSING               (1UL << 3)
+#define BTRFS_DEV_STATE_CAN_DISCARD    (1UL << 4)
struct btrfs_device {
        struct list_head dev_list;
@@ -74,7 +75,6 @@ struct btrfs_device {
        fmode_t mode;
unsigned long dev_state;
-       int can_discard;
        int is_tgtdev_for_dev_replace;
        blk_status_t last_flush_error;
        int flush_bio_sent;

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to