btrfs: Convert name_cache to XArray

This is a very straightforward conversion.  The handling of collisions
in the namecache could be better handled with an hlist, but that's a
patch for another day.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index c3c0c064c25dadd317841e1d2761e2629b6ec9f3..b243e649e9309ea203f76a729da2f6d95fa46c70 100644 (file)
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -10,7 +10,7 @@
 #include <linux/mount.h>
 #include <linux/xattr.h>
 #include <linux/posix_acl_xattr.h>
-#include <linux/radix-tree.h>
+#include <linux/xarray.h>
 #include <linux/vmalloc.h>
 #include <linux/string.h>
 #include <linux/compat.h>
@@ -107,7 +107,7 @@ struct send_ctx {
        struct list_head new_refs;
        struct list_head deleted_refs;
 
-       struct radix_tree_root name_cache;
+       struct xarray name_cache;
        struct list_head name_cache_list;
        int name_cache_size;
 
@@ -242,12 +242,12 @@ struct orphan_dir_info {
 struct name_cache_entry {
        struct list_head list;
        /*
-        * radix_tree has only 32bit entries but we need to handle 64bit inums.
-        * We use the lower 32bit of the 64bit inum to store it in the tree. If
-        * more then one inum would fall into the same entry, we use radix_list
-        * to store the additional entries. radix_list is also used to store
-        * entries where two entries have the same inum but different
-        * generations.
+        * xarray has only 32bit indices but we need to handle 64bit inums.
+        * We use the lower 32bit of the 64bit inum to store it in the array.
+        * If more then one inum would fall into the same entry, we use
+        * radix_list to store the additional entries. radix_list is also
+        * used to store entries where two entries have the same inum but
+        * different generations.
         */
        struct list_head radix_list;
        u64 ino;
@@ -1984,8 +1984,7 @@ static int name_cache_insert(struct send_ctx *sctx,
        int ret = 0;
        struct list_head *nce_head;
 
-       nce_head = radix_tree_lookup(&sctx->name_cache,
-                       (unsigned long)nce->ino);
+       nce_head = xa_load(&sctx->name_cache, (unsigned long)nce->ino);
        if (!nce_head) {
                nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL);
                if (!nce_head) {
@@ -1994,7 +1993,8 @@ static int name_cache_insert(struct send_ctx *sctx,
                }
                INIT_LIST_HEAD(nce_head);
 
-               ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
+               ret = xa_insert(&sctx->name_cache, nce->ino, nce_head,
+                                                               GFP_KERNEL);
                if (ret < 0) {
                        kfree(nce_head);
                        kfree(nce);
@@ -2013,8 +2013,7 @@ static void name_cache_delete(struct send_ctx *sctx,
 {
        struct list_head *nce_head;
 
-       nce_head = radix_tree_lookup(&sctx->name_cache,
-                       (unsigned long)nce->ino);
+       nce_head = xa_load(&sctx->name_cache, (unsigned long)nce->ino);
        if (!nce_head) {
                btrfs_err(sctx->send_root->fs_info,
              "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
@@ -2029,7 +2028,7 @@ static void name_cache_delete(struct send_ctx *sctx,
         * We may not get to the final release of nce_head if the lookup fails
         */
        if (nce_head && list_empty(nce_head)) {
-               radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
+               xa_erase(&sctx->name_cache, (unsigned long)nce->ino);
                kfree(nce_head);
        }
 }
@@ -2040,7 +2039,7 @@ static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
        struct list_head *nce_head;
        struct name_cache_entry *cur;
 
-       nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
+       nce_head = xa_load(&sctx->name_cache, (unsigned long)ino);
        if (!nce_head)
                return NULL;
 
@@ -6723,7 +6722,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 
        INIT_LIST_HEAD(&sctx->new_refs);
        INIT_LIST_HEAD(&sctx->deleted_refs);
-       INIT_RADIX_TREE(&sctx->name_cache, GFP_KERNEL);
+       xa_init(&sctx->name_cache);
        INIT_LIST_HEAD(&sctx->name_cache_list);
 
        sctx->flags = arg->flags;