btrfs: plumb level through the compression interface
[sfrench/cifs-2.6.git] / fs / btrfs / compression.c
index 548057630b69e9735d75eb1426869c85c0e521e9..ccd6bb2061f6ee6e3bccfff37c5ac186de8c5b6d 100644 (file)
@@ -730,6 +730,28 @@ struct heuristic_ws {
        struct list_head list;
 };
 
+static struct workspace_manager heuristic_wsm;
+
+static void heuristic_init_workspace_manager(void)
+{
+       btrfs_init_workspace_manager(&heuristic_wsm, &btrfs_heuristic_compress);
+}
+
+static void heuristic_cleanup_workspace_manager(void)
+{
+       btrfs_cleanup_workspace_manager(&heuristic_wsm);
+}
+
+static struct list_head *heuristic_get_workspace(unsigned int level)
+{
+       return btrfs_get_workspace(&heuristic_wsm, level);
+}
+
+static void heuristic_put_workspace(struct list_head *ws)
+{
+       btrfs_put_workspace(&heuristic_wsm, ws);
+}
+
 static void free_heuristic_ws(struct list_head *ws)
 {
        struct heuristic_ws *workspace;
@@ -742,7 +764,7 @@ static void free_heuristic_ws(struct list_head *ws)
        kfree(workspace);
 }
 
-static struct list_head *alloc_heuristic_ws(void)
+static struct list_head *alloc_heuristic_ws(unsigned int level)
 {
        struct heuristic_ws *ws;
 
@@ -769,65 +791,59 @@ fail:
        return ERR_PTR(-ENOMEM);
 }
 
-struct workspaces_list {
-       struct list_head idle_ws;
-       spinlock_t ws_lock;
-       /* Number of free workspaces */
-       int free_ws;
-       /* Total number of allocated workspaces */
-       atomic_t total_ws;
-       /* Waiters for a free workspace */
-       wait_queue_head_t ws_wait;
+const struct btrfs_compress_op btrfs_heuristic_compress = {
+       .init_workspace_manager = heuristic_init_workspace_manager,
+       .cleanup_workspace_manager = heuristic_cleanup_workspace_manager,
+       .get_workspace = heuristic_get_workspace,
+       .put_workspace = heuristic_put_workspace,
+       .alloc_workspace = alloc_heuristic_ws,
+       .free_workspace = free_heuristic_ws,
 };
 
-static struct workspaces_list btrfs_comp_ws[BTRFS_COMPRESS_TYPES];
-
-static struct workspaces_list btrfs_heuristic_ws;
-
 static const struct btrfs_compress_op * const btrfs_compress_op[] = {
+       /* The heuristic is represented as compression type 0 */
+       &btrfs_heuristic_compress,
        &btrfs_zlib_compress,
        &btrfs_lzo_compress,
        &btrfs_zstd_compress,
 };
 
-void __init btrfs_init_compress(void)
+void btrfs_init_workspace_manager(struct workspace_manager *wsm,
+                                 const struct btrfs_compress_op *ops)
 {
        struct list_head *workspace;
-       int i;
 
-       INIT_LIST_HEAD(&btrfs_heuristic_ws.idle_ws);
-       spin_lock_init(&btrfs_heuristic_ws.ws_lock);
-       atomic_set(&btrfs_heuristic_ws.total_ws, 0);
-       init_waitqueue_head(&btrfs_heuristic_ws.ws_wait);
+       wsm->ops = ops;
 
-       workspace = alloc_heuristic_ws();
+       INIT_LIST_HEAD(&wsm->idle_ws);
+       spin_lock_init(&wsm->ws_lock);
+       atomic_set(&wsm->total_ws, 0);
+       init_waitqueue_head(&wsm->ws_wait);
+
+       /*
+        * Preallocate one workspace for each compression type so we can
+        * guarantee forward progress in the worst case
+        */
+       workspace = wsm->ops->alloc_workspace(0);
        if (IS_ERR(workspace)) {
                pr_warn(
-       "BTRFS: cannot preallocate heuristic workspace, will try later\n");
+       "BTRFS: cannot preallocate compression workspace, will try later\n");
        } else {
-               atomic_set(&btrfs_heuristic_ws.total_ws, 1);
-               btrfs_heuristic_ws.free_ws = 1;
-               list_add(workspace, &btrfs_heuristic_ws.idle_ws);
+               atomic_set(&wsm->total_ws, 1);
+               wsm->free_ws = 1;
+               list_add(workspace, &wsm->idle_ws);
        }
+}
 
-       for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
-               INIT_LIST_HEAD(&btrfs_comp_ws[i].idle_ws);
-               spin_lock_init(&btrfs_comp_ws[i].ws_lock);
-               atomic_set(&btrfs_comp_ws[i].total_ws, 0);
-               init_waitqueue_head(&btrfs_comp_ws[i].ws_wait);
+void btrfs_cleanup_workspace_manager(struct workspace_manager *wsman)
+{
+       struct list_head *ws;
 
-               /*
-                * Preallocate one workspace for each compression type so
-                * we can guarantee forward progress in the worst case
-                */
-               workspace = btrfs_compress_op[i]->alloc_workspace();
-               if (IS_ERR(workspace)) {
-                       pr_warn("BTRFS: cannot preallocate compression workspace, will try later\n");
-               } else {
-                       atomic_set(&btrfs_comp_ws[i].total_ws, 1);
-                       btrfs_comp_ws[i].free_ws = 1;
-                       list_add(workspace, &btrfs_comp_ws[i].idle_ws);
-               }
+       while (!list_empty(&wsman->idle_ws)) {
+               ws = wsman->idle_ws.next;
+               list_del(ws);
+               wsman->ops->free_workspace(ws);
+               atomic_dec(&wsman->total_ws);
        }
 }
 
@@ -837,11 +853,11 @@ void __init btrfs_init_compress(void)
  * Preallocation makes a forward progress guarantees and we do not return
  * errors.
  */
-static struct list_head *__find_workspace(int type, bool heuristic)
+struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
+                                     unsigned int level)
 {
        struct list_head *workspace;
        int cpus = num_online_cpus();
-       int idx = type - 1;
        unsigned nofs_flag;
        struct list_head *idle_ws;
        spinlock_t *ws_lock;
@@ -849,19 +865,11 @@ static struct list_head *__find_workspace(int type, bool heuristic)
        wait_queue_head_t *ws_wait;
        int *free_ws;
 
-       if (heuristic) {
-               idle_ws  = &btrfs_heuristic_ws.idle_ws;
-               ws_lock  = &btrfs_heuristic_ws.ws_lock;
-               total_ws = &btrfs_heuristic_ws.total_ws;
-               ws_wait  = &btrfs_heuristic_ws.ws_wait;
-               free_ws  = &btrfs_heuristic_ws.free_ws;
-       } else {
-               idle_ws  = &btrfs_comp_ws[idx].idle_ws;
-               ws_lock  = &btrfs_comp_ws[idx].ws_lock;
-               total_ws = &btrfs_comp_ws[idx].total_ws;
-               ws_wait  = &btrfs_comp_ws[idx].ws_wait;
-               free_ws  = &btrfs_comp_ws[idx].free_ws;
-       }
+       idle_ws  = &wsm->idle_ws;
+       ws_lock  = &wsm->ws_lock;
+       total_ws = &wsm->total_ws;
+       ws_wait  = &wsm->ws_wait;
+       free_ws  = &wsm->free_ws;
 
 again:
        spin_lock(ws_lock);
@@ -892,10 +900,7 @@ again:
         * context of btrfs_compress_bio/btrfs_compress_pages
         */
        nofs_flag = memalloc_nofs_save();
-       if (heuristic)
-               workspace = alloc_heuristic_ws();
-       else
-               workspace = btrfs_compress_op[idx]->alloc_workspace();
+       workspace = wsm->ops->alloc_workspace(level);
        memalloc_nofs_restore(nofs_flag);
 
        if (IS_ERR(workspace)) {
@@ -926,85 +931,47 @@ again:
        return workspace;
 }
 
-static struct list_head *find_workspace(int type)
+static struct list_head *get_workspace(int type, int level)
 {
-       return __find_workspace(type, false);
+       return btrfs_compress_op[type]->get_workspace(level);
 }
 
 /*
  * put a workspace struct back on the list or free it if we have enough
  * idle ones sitting around
  */
-static void __free_workspace(int type, struct list_head *workspace,
-                            bool heuristic)
+void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws)
 {
-       int idx = type - 1;
        struct list_head *idle_ws;
        spinlock_t *ws_lock;
        atomic_t *total_ws;
        wait_queue_head_t *ws_wait;
        int *free_ws;
 
-       if (heuristic) {
-               idle_ws  = &btrfs_heuristic_ws.idle_ws;
-               ws_lock  = &btrfs_heuristic_ws.ws_lock;
-               total_ws = &btrfs_heuristic_ws.total_ws;
-               ws_wait  = &btrfs_heuristic_ws.ws_wait;
-               free_ws  = &btrfs_heuristic_ws.free_ws;
-       } else {
-               idle_ws  = &btrfs_comp_ws[idx].idle_ws;
-               ws_lock  = &btrfs_comp_ws[idx].ws_lock;
-               total_ws = &btrfs_comp_ws[idx].total_ws;
-               ws_wait  = &btrfs_comp_ws[idx].ws_wait;
-               free_ws  = &btrfs_comp_ws[idx].free_ws;
-       }
+       idle_ws  = &wsm->idle_ws;
+       ws_lock  = &wsm->ws_lock;
+       total_ws = &wsm->total_ws;
+       ws_wait  = &wsm->ws_wait;
+       free_ws  = &wsm->free_ws;
 
        spin_lock(ws_lock);
        if (*free_ws <= num_online_cpus()) {
-               list_add(workspace, idle_ws);
+               list_add(ws, idle_ws);
                (*free_ws)++;
                spin_unlock(ws_lock);
                goto wake;
        }
        spin_unlock(ws_lock);
 
-       if (heuristic)
-               free_heuristic_ws(workspace);
-       else
-               btrfs_compress_op[idx]->free_workspace(workspace);
+       wsm->ops->free_workspace(ws);
        atomic_dec(total_ws);
 wake:
        cond_wake_up(ws_wait);
 }
 
-static void free_workspace(int type, struct list_head *ws)
+static void put_workspace(int type, struct list_head *ws)
 {
-       return __free_workspace(type, ws, false);
-}
-
-/*
- * cleanup function for module exit
- */
-static void free_workspaces(void)
-{
-       struct list_head *workspace;
-       int i;
-
-       while (!list_empty(&btrfs_heuristic_ws.idle_ws)) {
-               workspace = btrfs_heuristic_ws.idle_ws.next;
-               list_del(workspace);
-               free_heuristic_ws(workspace);
-               atomic_dec(&btrfs_heuristic_ws.total_ws);
-       }
-
-       for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
-               while (!list_empty(&btrfs_comp_ws[i].idle_ws)) {
-                       workspace = btrfs_comp_ws[i].idle_ws.next;
-                       list_del(workspace);
-                       btrfs_compress_op[i]->free_workspace(workspace);
-                       atomic_dec(&btrfs_comp_ws[i].total_ws);
-               }
-       }
+       return btrfs_compress_op[type]->put_workspace(ws);
 }
 
 /*
@@ -1036,18 +1003,19 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
                         unsigned long *total_in,
                         unsigned long *total_out)
 {
+       int type = btrfs_compress_type(type_level);
+       int level = btrfs_compress_level(type_level);
        struct list_head *workspace;
        int ret;
-       int type = type_level & 0xF;
 
-       workspace = find_workspace(type);
+       workspace = get_workspace(type, level);
 
-       btrfs_compress_op[type - 1]->set_level(workspace, type_level);
-       ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping,
+       btrfs_compress_op[type]->set_level(workspace, level);
+       ret = btrfs_compress_op[type]->compress_pages(workspace, mapping,
                                                      start, pages,
                                                      out_pages,
                                                      total_in, total_out);
-       free_workspace(type, workspace);
+       put_workspace(type, workspace);
        return ret;
 }
 
@@ -1071,9 +1039,9 @@ static int btrfs_decompress_bio(struct compressed_bio *cb)
        int ret;
        int type = cb->compress_type;
 
-       workspace = find_workspace(type);
-       ret = btrfs_compress_op[type - 1]->decompress_bio(workspace, cb);
-       free_workspace(type, workspace);
+       workspace = get_workspace(type, 0);
+       ret = btrfs_compress_op[type]->decompress_bio(workspace, cb);
+       put_workspace(type, workspace);
 
        return ret;
 }
@@ -1089,19 +1057,29 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
        struct list_head *workspace;
        int ret;
 
-       workspace = find_workspace(type);
-
-       ret = btrfs_compress_op[type-1]->decompress(workspace, data_in,
+       workspace = get_workspace(type, 0);
+       ret = btrfs_compress_op[type]->decompress(workspace, data_in,
                                                  dest_page, start_byte,
                                                  srclen, destlen);
+       put_workspace(type, workspace);
 
-       free_workspace(type, workspace);
        return ret;
 }
 
+void __init btrfs_init_compress(void)
+{
+       int i;
+
+       for (i = 0; i < BTRFS_NR_WORKSPACE_MANAGERS; i++)
+               btrfs_compress_op[i]->init_workspace_manager();
+}
+
 void __cold btrfs_exit_compress(void)
 {
-       free_workspaces();
+       int i;
+
+       for (i = 0; i < BTRFS_NR_WORKSPACE_MANAGERS; i++)
+               btrfs_compress_op[i]->cleanup_workspace_manager();
 }
 
 /*
@@ -1512,7 +1490,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
  */
 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
 {
-       struct list_head *ws_list = __find_workspace(0, true);
+       struct list_head *ws_list = get_workspace(0, 0);
        struct heuristic_ws *ws;
        u32 i;
        u8 byte;
@@ -1581,7 +1559,7 @@ int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
        }
 
 out:
-       __free_workspace(0, ws_list, true);
+       put_workspace(0, ws_list);
        return ret;
 }