Add backing_device_info per-filesystem

[zfs.git] / module / zfs / zfs_vfsops.c

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index e0987e9..31692f4 100644 (file)
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -600,6 +600,12 @@ zfs_sb_create(const char *osname, zfs_sb_t **zsbp)
        zsb->z_show_ctldir = ZFS_SNAPDIR_VISIBLE;
        zsb->z_os = os;
 
+       error = -bdi_init(&zsb->z_bdi);
+       if (error) {
+               kmem_free(zsb, sizeof (zfs_sb_t));
+               return (error);
+       }
+
        error = zfs_get_zplprop(os, ZFS_PROP_VERSION, &zsb->z_version);
        if (error) {
                goto out;
@@ -799,6 +805,7 @@ zfs_sb_free(zfs_sb_t *zsb)
 
        zfs_fuid_destroy(zsb);
 
+       bdi_destroy(&zsb->z_bdi);
        mutex_destroy(&zsb->z_znodes_lock);
        mutex_destroy(&zsb->z_lock);
        list_destroy(&zsb->z_all_znodes);
@@ -1077,6 +1084,10 @@ zfsvfs_teardown(zfs_sb_t *zsb, boolean_t unmounting)
        return (0);
 }
 
+#ifdef HAVE_BDI
+static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
+#endif /* HAVE_BDI */
+
 int
 zfs_domount(struct super_block *sb, void *data, int silent)
 {
@@ -1102,6 +1113,7 @@ zfs_domount(struct super_block *sb, void *data, int silent)
        sb->s_time_gran = 1;
        sb->s_blocksize = recordsize;
        sb->s_blocksize_bits = ilog2(recordsize);
+       bdi_put_sb(sb, NULL);
 
        /* Set callback operations for the file system. */
        sb->s_op = &zpl_super_operations;
@@ -1126,6 +1138,16 @@ zfs_domount(struct super_block *sb, void *data, int silent)
                dmu_objset_set_user(zsb->z_os, zsb);
                mutex_exit(&zsb->z_os->os_user_ptr_lock);
        } else {
+               /* Disable Linux read-ahead handled by lower layers */
+               zsb->z_bdi.ra_pages = 0;
+
+               error = -bdi_register(&zsb->z_bdi, NULL, "zfs-%d",
+                   atomic_long_inc_return(&bdi_seq));
+               if (error)
+                       goto out;
+
+               bdi_put_sb(sb, &zsb->z_bdi);
+
                error = zfs_sb_setup(zsb, B_TRUE);
 #ifdef HAVE_SNAPSHOT
                (void) zfs_snap_create(zsb);
@@ -1166,6 +1188,11 @@ zfs_umount(struct super_block *sb)
        VERIFY(zfsvfs_teardown(zsb, B_TRUE) == 0);
        os = zsb->z_os;
 
+       if (bdi_get_sb(sb)) {
+               bdi_unregister(bdi_get_sb(sb));
+               bdi_put_sb(sb, NULL);
+       }
+
        /*
         * z_os will be NULL if there was an error in
         * attempting to reopen zsb.