Commit c63e09ecccb5 "Make allocation of anon devices cheaper" made
a performance-driven change in 2009.
With commit 2c57a0e233d7 "lib: find_*_bit reimplementation" the
performance of the related functionality was much improved in 2015,
so I think we can remove this older extension.
However I didn't do any benchmarking.
As a result of this change we use the idr functionality the same way
as other parts of the kernel.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
fs/super.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)
diff --git a/fs/super.c b/fs/super.c
index c2ff475..362e765 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -881,10 +881,6 @@ void emergency_remount(void)
static DEFINE_IDA(unnamed_dev_ida);
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
-/* Many userspace utilities consider an FSID of 0 invalid.
- * Always return at least 1 from get_anon_bdev.
- */
-static int unnamed_dev_start = 1;
int get_anon_bdev(dev_t *p)
{
@@ -895,9 +891,10 @@ int get_anon_bdev(dev_t *p)
if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0)
return -ENOMEM;
spin_lock(&unnamed_dev_lock);
- error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev);
- if (!error)
- unnamed_dev_start = dev + 1;
+ /* Many userspace utilities consider an FSID of 0 invalid.
+ * Always return at least 1 from get_anon_bdev.
+ */
+ error = ida_get_new_above(&unnamed_dev_ida, 1, &dev);
spin_unlock(&unnamed_dev_lock);
if (error == -EAGAIN)
/* We raced and lost with another CPU. */
@@ -908,8 +905,6 @@ int get_anon_bdev(dev_t *p)
if (dev >= (1 << MINORBITS)) {
spin_lock(&unnamed_dev_lock);
ida_remove(&unnamed_dev_ida, dev);
- if (unnamed_dev_start > dev)
- unnamed_dev_start = dev;
spin_unlock(&unnamed_dev_lock);
return -EMFILE;
}
@@ -923,8 +918,6 @@ void free_anon_bdev(dev_t dev)
int slot = MINOR(dev);
spin_lock(&unnamed_dev_lock);
ida_remove(&unnamed_dev_ida, slot);
- if (slot < unnamed_dev_start)
- unnamed_dev_start = slot;
spin_unlock(&unnamed_dev_lock);
}
EXPORT_SYMBOL(free_anon_bdev);
--
2.9.0
--
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