[PATCH v2 25/30] fuse: Maintain a list of busy elements

Vivek Goyal
2019-05-15T19:28:58Z

This list will be used selecting fuse_dax_mapping to free when number of
free mappings drops below a threshold.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
fs/fuse/file.c | 8 ++++++++
fs/fuse/fuse_i.h | 7 +++++++
fs/fuse/inode.c | 4 ++++
3 files changed, 19 insertions(+)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index e536a04aaa06..3f0f7a387341 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -273,6 +273,10 @@ static int fuse_setup_one_mapping(struct inode *inode,
/* Protected by fi->i_dmap_sem */
fuse_dax_interval_tree_insert(dmap, &fi->dmap_tree);
fi->nr_dmaps++;
+ spin_lock(&fc->lock);
+ list_add_tail(&dmap->busy_list, &fc->busy_ranges);
+ fc->nr_busy_ranges++;
+ spin_unlock(&fc->lock);
return 0;
}

@@ -317,6 +321,10 @@ void fuse_removemapping(struct inode *inode)
if (dmap) {
fuse_dax_interval_tree_remove(dmap, &fi->dmap_tree);
fi->nr_dmaps--;
+ spin_lock(&fc->lock);
+ list_del_init(&dmap->busy_list);
+ fc->nr_busy_ranges--;
+ spin_unlock(&fc->lock);
}

if (!dmap)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index a234cf30538d..c93e9155b723 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -114,6 +114,9 @@ struct fuse_dax_mapping {
__u64 end;
__u64 __subtree_last;

+ /* Will connect in fc->busy_ranges to keep track busy memory */
+ struct list_head busy_list;
+
/** Position in DAX window */
u64 window_offset;

@@ -873,6 +876,10 @@ struct fuse_conn {
/** DAX device, non-NULL if DAX is supported */
struct dax_device *dax_dev;

+ /* List of memory ranges which are busy */
+ unsigned long nr_busy_ranges;
+ struct list_head busy_ranges;
+
/*
* DAX Window Free Ranges. TODO: This might not be best place to store
* this free list
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 713c5f32ab35..f57f7ce02acc 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -626,6 +626,8 @@ static void fuse_free_dax_mem_ranges(struct list_head *mem_list)
/* Free All allocated elements */
list_for_each_entry_safe(range, temp, mem_list, list) {
list_del(&range->list);
+ if (!list_empty(&range->busy_list))
+ list_del(&range->busy_list);
kfree(range);
}
}
@@ -670,6 +672,7 @@ static int fuse_dax_mem_range_init(struct fuse_conn *fc,
*/
range->window_offset = i * FUSE_DAX_MEM_RANGE_SZ;
range->length = FUSE_DAX_MEM_RANGE_SZ;
+ INIT_LIST_HEAD(&range->busy_list);
list_add_tail(&range->list, &mem_ranges);
}

@@ -720,6 +723,7 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
fc->user_ns = get_user_ns(user_ns);
fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
INIT_LIST_HEAD(&fc->free_ranges);
+ INIT_LIST_HEAD(&fc->busy_ranges);
}
EXPORT_SYMBOL_GPL(fuse_conn_init);

--
2.20.1