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Message-Id: <20180117202203.19756-87-willy@infradead.org>
Date: Wed, 17 Jan 2018 12:21:50 -0800
From: Matthew Wilcox <willy@...radead.org>
To: linux-kernel@...r.kernel.org
Cc: Matthew Wilcox <mawilcox@...rosoft.com>, linux-mm@...ck.org,
linux-fsdevel@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net,
linux-nilfs@...r.kernel.org, linux-btrfs@...r.kernel.org,
linux-xfs@...r.kernel.org, linux-usb@...r.kernel.org,
Bjorn Andersson <bjorn.andersson@...aro.org>,
Stefano Stabellini <sstabellini@...nel.org>,
iommu@...ts.linux-foundation.org, linux-remoteproc@...r.kernel.org,
linux-s390@...r.kernel.org, intel-gfx@...ts.freedesktop.org,
cgroups@...r.kernel.org, linux-sh@...r.kernel.org,
David Howells <dhowells@...hat.com>
Subject: [PATCH v6 86/99] btrfs: Convert reada_zones to XArray
From: Matthew Wilcox <mawilcox@...rosoft.com>
The use of the reada_lock means we have to use the xa_reserve() API.
If we can avoid using reada_lock to protect this xarray, we can drop
the use of that function.
Signed-off-by: Matthew Wilcox <mawilcox@...rosoft.com>
---
fs/btrfs/reada.c | 54 +++++++++++++++++++-----------------------------------
fs/btrfs/volumes.c | 2 +-
fs/btrfs/volumes.h | 2 +-
3 files changed, 21 insertions(+), 37 deletions(-)
diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index ab852b8e3e37..ef8e84ff2012 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -239,17 +239,16 @@ static struct reada_zone *reada_find_zone(struct btrfs_device *dev, u64 logical,
{
struct btrfs_fs_info *fs_info = dev->fs_info;
int ret;
- struct reada_zone *zone;
+ struct reada_zone *curr, *zone;
struct btrfs_block_group_cache *cache = NULL;
u64 start;
u64 end;
+ unsigned long index = logical >> PAGE_SHIFT;
int i;
- zone = NULL;
spin_lock(&fs_info->reada_lock);
- ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,
- logical >> PAGE_SHIFT, 1);
- if (ret == 1 && logical >= zone->start && logical <= zone->end) {
+ zone = xa_find(&dev->reada_zones, &index, ULONG_MAX, XA_PRESENT);
+ if (zone && logical >= zone->start && logical <= zone->end) {
kref_get(&zone->refcnt);
spin_unlock(&fs_info->reada_lock);
return zone;
@@ -269,7 +268,8 @@ static struct reada_zone *reada_find_zone(struct btrfs_device *dev, u64 logical,
if (!zone)
return NULL;
- ret = radix_tree_preload(GFP_KERNEL);
+ ret = xa_reserve(&dev->reada_zones,
+ (unsigned long)(end >> PAGE_SHIFT), GFP_KERNEL);
if (ret) {
kfree(zone);
return NULL;
@@ -290,21 +290,18 @@ static struct reada_zone *reada_find_zone(struct btrfs_device *dev, u64 logical,
zone->ndevs = bbio->num_stripes;
spin_lock(&fs_info->reada_lock);
- ret = radix_tree_insert(&dev->reada_zones,
+ curr = xa_cmpxchg(&dev->reada_zones,
(unsigned long)(zone->end >> PAGE_SHIFT),
- zone);
-
- if (ret == -EEXIST) {
+ NULL, zone, GFP_NOWAIT | __GFP_NOWARN);
+ if (curr) {
kfree(zone);
- ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,
- logical >> PAGE_SHIFT, 1);
- if (ret == 1 && logical >= zone->start && logical <= zone->end)
+ zone = curr;
+ if (logical >= zone->start && logical <= zone->end)
kref_get(&zone->refcnt);
else
zone = NULL;
}
spin_unlock(&fs_info->reada_lock);
- radix_tree_preload_end();
return zone;
}
@@ -537,9 +534,7 @@ static void reada_zone_release(struct kref *kref)
{
struct reada_zone *zone = container_of(kref, struct reada_zone, refcnt);
- radix_tree_delete(&zone->device->reada_zones,
- zone->end >> PAGE_SHIFT);
-
+ xa_erase(&zone->device->reada_zones, zone->end >> PAGE_SHIFT);
kfree(zone);
}
@@ -592,7 +587,7 @@ static void reada_peer_zones_set_lock(struct reada_zone *zone, int lock)
for (i = 0; i < zone->ndevs; ++i) {
struct reada_zone *peer;
- peer = radix_tree_lookup(&zone->devs[i]->reada_zones, index);
+ peer = xa_load(&zone->devs[i]->reada_zones, index);
if (peer && peer->device != zone->device)
peer->locked = lock;
}
@@ -603,12 +598,11 @@ static void reada_peer_zones_set_lock(struct reada_zone *zone, int lock)
*/
static int reada_pick_zone(struct btrfs_device *dev)
{
- struct reada_zone *top_zone = NULL;
+ struct reada_zone *zone, *top_zone = NULL;
struct reada_zone *top_locked_zone = NULL;
u64 top_elems = 0;
u64 top_locked_elems = 0;
unsigned long index = 0;
- int ret;
if (dev->reada_curr_zone) {
reada_peer_zones_set_lock(dev->reada_curr_zone, 0);
@@ -616,14 +610,7 @@ static int reada_pick_zone(struct btrfs_device *dev)
dev->reada_curr_zone = NULL;
}
/* pick the zone with the most elements */
- while (1) {
- struct reada_zone *zone;
-
- ret = radix_tree_gang_lookup(&dev->reada_zones,
- (void **)&zone, index, 1);
- if (ret == 0)
- break;
- index = (zone->end >> PAGE_SHIFT) + 1;
+ xa_for_each(&dev->reada_zones, zone, index, ULONG_MAX, XA_PRESENT) {
if (zone->locked) {
if (zone->elems > top_locked_elems) {
top_locked_elems = zone->elems;
@@ -819,15 +806,13 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
spin_lock(&fs_info->reada_lock);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ struct reada_zone *zone;
+
btrfs_debug(fs_info, "dev %lld has %d in flight", device->devid,
atomic_read(&device->reada_in_flight));
index = 0;
- while (1) {
- struct reada_zone *zone;
- ret = radix_tree_gang_lookup(&device->reada_zones,
- (void **)&zone, index, 1);
- if (ret == 0)
- break;
+ xa_for_each(&dev->reada_zones, zone, index, ULONG_MAX,
+ XA_PRESENT) {
pr_debug(" zone %llu-%llu elems %llu locked %d devs",
zone->start, zone->end, zone->elems,
zone->locked);
@@ -839,7 +824,6 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
pr_cont(" curr off %llu",
device->reada_next - zone->start);
pr_cont("\n");
- index = (zone->end >> PAGE_SHIFT) + 1;
}
cnt = 0;
index = 0;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index cba286183ff9..8e683799b436 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -247,7 +247,7 @@ static struct btrfs_device *__alloc_device(void)
atomic_set(&dev->reada_in_flight, 0);
atomic_set(&dev->dev_stats_ccnt, 0);
btrfs_device_data_ordered_init(dev);
- INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+ xa_init(&dev->reada_zones);
INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
return dev;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 335fd1590458..aeabe03d3e44 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -139,7 +139,7 @@ struct btrfs_device {
atomic_t reada_in_flight;
u64 reada_next;
struct reada_zone *reada_curr_zone;
- struct radix_tree_root reada_zones;
+ struct xarray reada_zones;
struct radix_tree_root reada_extents;
/* disk I/O failure stats. For detailed description refer to
--
2.15.1
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