| Message ID | 20200206104214.400857-10-naohiro.aota@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: refactor and generalize chunk/dev_extent/extent allocation | expand |
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@wdc.com> > --- > 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, Josef
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@wdc.com> >>--- >> 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.
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) continue; ret = find_free_dev_extent(device, dev_extent_want, &dev_offset, @@ -4942,12 +4943,12 @@ static int gather_device_info(struct btrfs_fs_devices *fs_devices, if (ret == 0) max_avail = dev_extent_want; - if (max_avail < dev_extent_min) { + if (max_avail < ctl->dev_extent_min) { if (btrfs_test_opt(info, ENOSPC_DEBUG)) btrfs_debug(info, "%s: devid %llu has no free space, have=%llu want=%llu", __func__, device->devid, max_avail, - dev_extent_min); + ctl->dev_extent_min); continue; }
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@wdc.com> --- fs/btrfs/volumes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)