From d0cfb9dcbca6ebd21ec78ea719b451ea4c22cecf Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 19 Aug 2020 18:19:55 -0400 Subject: [PATCH] virtiofs: maintain a list of busy elements 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 Signed-off-by: Miklos Szeredi --- fs/fuse/dax.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c index efc1a8e..e640783 100644 --- a/fs/fuse/dax.c +++ b/fs/fuse/dax.c @@ -28,6 +28,9 @@ struct fuse_dax_mapping { /* For interval tree in file/inode */ struct interval_tree_node itn; + /* Will connect in fc->busy_ranges to keep track busy memory */ + struct list_head busy_list; + /** Position in DAX window */ u64 window_offset; @@ -55,6 +58,10 @@ struct fuse_conn_dax { /* Lock protecting accessess to members of this structure */ spinlock_t lock; + /* List of memory ranges which are busy */ + unsigned long nr_busy_ranges; + struct list_head busy_ranges; + /* DAX Window Free Ranges */ long nr_free_ranges; struct list_head free_ranges; @@ -86,6 +93,15 @@ static struct fuse_dax_mapping *alloc_dax_mapping(struct fuse_conn_dax *fcd) } /* This assumes fcd->lock is held */ +static void __dmap_remove_busy_list(struct fuse_conn_dax *fcd, + struct fuse_dax_mapping *dmap) +{ + list_del_init(&dmap->busy_list); + WARN_ON(fcd->nr_busy_ranges == 0); + fcd->nr_busy_ranges--; +} + +/* This assumes fcd->lock is held */ static void __dmap_add_to_free_pool(struct fuse_conn_dax *fcd, struct fuse_dax_mapping *dmap) { @@ -139,6 +155,10 @@ static int fuse_setup_one_mapping(struct inode *inode, unsigned long start_idx, /* Protected by fi->dax->sem */ interval_tree_insert(&dmap->itn, &fi->dax->tree); fi->dax->nr++; + spin_lock(&fcd->lock); + list_add_tail(&dmap->busy_list, &fcd->busy_ranges); + fcd->nr_busy_ranges++; + spin_unlock(&fcd->lock); } return 0; } @@ -207,6 +227,7 @@ static void dmap_reinit_add_to_free_pool(struct fuse_conn_dax *fcd, pr_debug("fuse: freeing memory range start_idx=0x%lx end_idx=0x%lx window_offset=0x%llx length=0x%llx\n", dmap->itn.start, dmap->itn.last, dmap->window_offset, dmap->length); + __dmap_remove_busy_list(fcd, dmap); dmap->itn.start = dmap->itn.last = 0; __dmap_add_to_free_pool(fcd, dmap); } @@ -700,6 +721,8 @@ 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); } } @@ -723,6 +746,7 @@ static int fuse_dax_mem_range_init(struct fuse_conn_dax *fcd) unsigned long i; INIT_LIST_HEAD(&fcd->free_ranges); + INIT_LIST_HEAD(&fcd->busy_ranges); id = dax_read_lock(); nr_pages = dax_direct_access(fcd->dev, 0, PHYS_PFN(dax_size), &kaddr, &pfn); @@ -748,6 +772,7 @@ static int fuse_dax_mem_range_init(struct fuse_conn_dax *fcd) */ range->window_offset = i * FUSE_DAX_SZ; range->length = FUSE_DAX_SZ; + INIT_LIST_HEAD(&range->busy_list); list_add_tail(&range->list, &fcd->free_ranges); } -- 2.7.4