On Thu, Feb 06, 2020 at 11:52:19AM -0500, Josef Bacik wrote:
On 2/6/20 5:42 AM, Naohiro Aota wrote:
Currently, we ignore a device whose available space is less than
"BTRFS_STRIPE_LEN * dev_stripes". This is a lower limit for current
allocation policy (to maximize the number of stripes). This commit
parameterizes dev_extent_min, so that other policies can set their own
lower limitation to ignore a device with an insufficient space.
Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
---
fs/btrfs/volumes.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 15837374db9c..4a6cc098ee3e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4836,6 +4836,7 @@ struct alloc_chunk_ctl {
store parity information */
u64 max_stripe_size;
u64 max_chunk_size;
+ u64 dev_extent_min;
u64 stripe_size;
u64 chunk_size;
int ndevs;
@@ -4868,6 +4869,7 @@ static void set_parameters_regular(struct btrfs_fs_devices *fs_devices,
/* We don't want a chunk larger than 10% of writable space */
ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
ctl->max_chunk_size);
+ ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
}
static void set_parameters(struct btrfs_fs_devices *fs_devices,
@@ -4903,7 +4905,6 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *device;
u64 total_avail;
u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes;
- u64 dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
int ret;
int ndevs = 0;
u64 max_avail;
@@ -4931,7 +4932,7 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices,
total_avail = 0;
/* If there is no space on this device, skip it. */
- if (total_avail == 0)
+ if (total_avail < ctl->dev_extent_min)
This isn't correct, dev_extent_min is the total size with all stripes
added up, not the size of a single stripe. Thanks,
Hm, I can revert here, but isn't it no use to search into a device
whose available bytes is less than dev_extent_min (= BTRFS_STRIPE_LEN
* ctl->dev_stripes)? Since max_avail can only be less than
dev_extent_min, we anyway skip such device with the below "if
(max_avail < dev_extent_min) { ... }" part.
