From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
Historically, when generic percpu counters were introduced in xfs for
free block counters by commit 0d485ada404b ("xfs: use generic percpu
counters for free block counter"), the counters used a custom batch
size. In xfs_mod_freecounter(), originally named xfs_mod_fdblocks(),
this patch attempted to serialize the program using a smaller batch size
as parameter to the addition function as the counter approaches 0.
Commit 8c1903d3081a ("xfs: inode and free block counters need to use
__percpu_counter_compare") pointed out the error in commit 0d485ada404b
("xfs: use generic percpu counters for free block counter") mentioned
above and said that "Because the counters use a custom batch size, the
comparison functions need to be aware of that batch size otherwise the
comparison does not work correctly". Then percpu_counter_compare() was
replaced with __percpu_counter_compare() with parameter
XFS_FDBLOCKS_BATCH.
After commit 8c1903d3081a ("xfs: inode and free block counters need to
use __percpu_counter_compare"), the existence of the batch variable is
no longer necessary, so this patch is proposed to simplify the code by
removing it.
Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
---
Changelog:
v3: Resend for the second time
v2: https://lore.kernel.org/linux-xfs/20230918043344.890817-1-alexjlzheng@xxxxxxxxxxx/
v1: https://lore.kernel.org/linux-xfs/20230908235713.GP28202@frogsfrogsfrogs/T/#t
---
fs/xfs/xfs_mount.c | 17 +----------------
1 file changed, 1 insertion(+), 16 deletions(-)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index aed5be5508fe..8e47a3040893 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1144,7 +1144,6 @@ xfs_mod_freecounter(
int64_t lcounter;
long long res_used;
uint64_t set_aside = 0;
- s32 batch;
bool has_resv_pool;
ASSERT(counter == &mp->m_fdblocks || counter == &mp->m_frextents);
@@ -1177,20 +1176,6 @@ xfs_mod_freecounter(
return 0;
}
- /*
- * Taking blocks away, need to be more accurate the closer we
- * are to zero.
- *
- * If the counter has a value of less than 2 * max batch size,
- * then make everything serialise as we are real close to
- * ENOSPC.
- */
- if (__percpu_counter_compare(counter, 2 * XFS_FDBLOCKS_BATCH,
- XFS_FDBLOCKS_BATCH) < 0)
- batch = 1;
- else
- batch = XFS_FDBLOCKS_BATCH;
-
/*
* Set aside allocbt blocks because these blocks are tracked as free
* space but not available for allocation. Technically this means that a
@@ -1204,7 +1189,7 @@ xfs_mod_freecounter(
*/
if (has_resv_pool)
set_aside = xfs_fdblocks_unavailable(mp);
- percpu_counter_add_batch(counter, delta, batch);
+ percpu_counter_add_batch(counter, delta, XFS_FDBLOCKS_BATCH);
if (__percpu_counter_compare(counter, set_aside,
XFS_FDBLOCKS_BATCH) >= 0) {
/* we had space! */
--
2.39.3
