Btrfs: sysfs: move super_kobj and device_dir_kobj from fs_info to btrfs_fs_devices

This patch will provide a framework and help to create attributes
from the structure btrfs_fs_devices which are available even before
fs_info is created. So by moving the parent kobject super_kobj from
fs_info to btrfs_fs_devices, it will help to create attributes
from the btrfs_fs_devices as well.

Patches on top of this patch now will be able to create the
sys/fs/btrfs/fsid kobject and attributes from btrfs_fs_devices
when devices are scanned and registered to the kernel.

Just to note, this does not change any of the existing btrfs sysfs
external kobject names and its attributes and not even the life
cycle of them. Changes are internal only. And to ensure the same,
this path has been tested with various device operations and,
checking and comparing the sysfs kobjects and attributes with
sysfs kobject and attributes with out this patch, and they remain
same.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6f364e1d8d3d1e9c08e246dbc1df443be49c33fd..3335245f2636ea6a0bb801318390d2aca369e23c 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1619,10 +1619,7 @@ struct btrfs_fs_info {
        struct task_struct *cleaner_kthread;
        int thread_pool_size;
 
-       struct kobject super_kobj;
        struct kobject *space_info_kobj;
-       struct kobject *device_dir_kobj;
-       struct completion kobj_unregister;
        int do_barriers;
        int closing;
        int log_root_recovering;

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index e71da324104a05a2ad30cc939611c84c6fbabaf9..f045c568b3603f5b492a7adb1a7fad00d712ab58 100644 (file)
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -33,6 +33,7 @@
 #include "volumes.h"
 
 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
+static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 
 static u64 get_features(struct btrfs_fs_info *fs_info,
                        enum btrfs_feature_set set)
@@ -438,10 +439,10 @@ static const struct attribute *btrfs_attrs[] = {
 
 static void btrfs_release_super_kobj(struct kobject *kobj)
 {
-       struct btrfs_fs_info *fs_info = to_fs_info(kobj);
+       struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
 
-       memset(&fs_info->super_kobj, 0, sizeof(struct kobject));
-       complete(&fs_info->kobj_unregister);
+       memset(&fs_devs->super_kobj, 0, sizeof(struct kobject));
+       complete(&fs_devs->kobj_unregister);
 }
 
 static struct kobj_type btrfs_ktype = {
@@ -449,11 +450,18 @@ static struct kobj_type btrfs_ktype = {
        .release        = btrfs_release_super_kobj,
 };
 
+static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
+{
+       if (kobj->ktype != &btrfs_ktype)
+               return NULL;
+       return container_of(kobj, struct btrfs_fs_devices, super_kobj);
+}
+
 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 {
        if (kobj->ktype != &btrfs_ktype)
                return NULL;
-       return container_of(kobj, struct btrfs_fs_info, super_kobj);
+       return to_fs_devs(kobj)->fs_info;
 }
 
 #define NUM_FEATURE_BITS 64
@@ -494,12 +502,12 @@ static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
                        attrs[0] = &fa->kobj_attr.attr;
                        if (add) {
                                int ret;
-                               ret = sysfs_merge_group(&fs_info->super_kobj,
+                               ret = sysfs_merge_group(&fs_info->fs_devices->super_kobj,
                                                        &agroup);
                                if (ret)
                                        return ret;
                        } else
-                               sysfs_unmerge_group(&fs_info->super_kobj,
+                               sysfs_unmerge_group(&fs_info->fs_devices->super_kobj,
                                                    &agroup);
                }
 
@@ -507,18 +515,17 @@ static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
        return 0;
 }
 
-static void btrfs_sysfs_remove_fsid(struct btrfs_fs_info *fs_info)
+static void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
 {
-       if (fs_info->device_dir_kobj) {
-               btrfs_kobj_rm_device(fs_info, NULL);
-               kobject_del(fs_info->device_dir_kobj);
-               kobject_put(fs_info->device_dir_kobj);
-               fs_info->device_dir_kobj = NULL;
+       if (fs_devs->device_dir_kobj) {
+               kobject_del(fs_devs->device_dir_kobj);
+               kobject_put(fs_devs->device_dir_kobj);
+               fs_devs->device_dir_kobj = NULL;
        }
 
-       kobject_del(&fs_info->super_kobj);
-       kobject_put(&fs_info->super_kobj);
-       wait_for_completion(&fs_info->kobj_unregister);
+       kobject_del(&fs_devs->super_kobj);
+       kobject_put(&fs_devs->super_kobj);
+       wait_for_completion(&fs_devs->kobj_unregister);
 }
 
 void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
@@ -529,9 +536,10 @@ void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
                kobject_put(fs_info->space_info_kobj);
        }
        addrm_unknown_feature_attrs(fs_info, false);
-       sysfs_remove_group(&fs_info->super_kobj, &btrfs_feature_attr_group);
-       sysfs_remove_files(&fs_info->super_kobj, btrfs_attrs);
-       btrfs_sysfs_remove_fsid(fs_info);
+       sysfs_remove_group(&fs_info->fs_devices->super_kobj, &btrfs_feature_attr_group);
+       sysfs_remove_files(&fs_info->fs_devices->super_kobj, btrfs_attrs);
+       btrfs_kobj_rm_device(fs_info, NULL);
+       btrfs_sysfs_remove_fsid(fs_info->fs_devices);
 }
 
 const char * const btrfs_feature_set_names[3] = {
@@ -617,14 +625,14 @@ int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
        struct hd_struct *disk;
        struct kobject *disk_kobj;
 
-       if (!fs_info->device_dir_kobj)
+       if (!fs_info->fs_devices->device_dir_kobj)
                return -EINVAL;
 
        if (one_device && one_device->bdev) {
                disk = one_device->bdev->bd_part;
                disk_kobj = &part_to_dev(disk)->kobj;
 
-               sysfs_remove_link(fs_info->device_dir_kobj,
+               sysfs_remove_link(fs_info->fs_devices->device_dir_kobj,
                                                disk_kobj->name);
        }
 
@@ -638,20 +646,20 @@ int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info,
                disk = one_device->bdev->bd_part;
                disk_kobj = &part_to_dev(disk)->kobj;
 
-               sysfs_remove_link(fs_info->device_dir_kobj,
+               sysfs_remove_link(fs_info->fs_devices->device_dir_kobj,
                                                disk_kobj->name);
        }
 
        return 0;
 }
 
-int btrfs_sysfs_add_device(struct btrfs_fs_info *fs_info)
+int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs)
 {
-       if (!fs_info->device_dir_kobj)
-               fs_info->device_dir_kobj = kobject_create_and_add("devices",
-                                               &fs_info->super_kobj);
+       if (!fs_devs->device_dir_kobj)
+               fs_devs->device_dir_kobj = kobject_create_and_add("devices",
+                                               &fs_devs->super_kobj);
 
-       if (!fs_info->device_dir_kobj)
+       if (!fs_devs->device_dir_kobj)
                return -ENOMEM;
 
        return 0;
@@ -664,7 +672,7 @@ int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
        struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
        struct btrfs_device *dev;
 
-       error = btrfs_sysfs_add_device(fs_info);
+       error = btrfs_sysfs_add_device(fs_devices);
        if (error)
                return error;
 
@@ -681,7 +689,7 @@ int btrfs_kobj_add_device(struct btrfs_fs_info *fs_info,
                disk = dev->bdev->bd_part;
                disk_kobj = &part_to_dev(disk)->kobj;
 
-               error = sysfs_create_link(fs_info->device_dir_kobj,
+               error = sysfs_create_link(fs_devices->device_dir_kobj,
                                          disk_kobj, disk_kobj->name);
                if (error)
                        break;
@@ -703,39 +711,41 @@ u64 btrfs_debugfs_test;
  * Can be called by the device discovery thread.
  * And parent can be specified for seed device
  */
-int btrfs_sysfs_add_fsid(struct btrfs_fs_info *fs_info,
+static int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
                                struct kobject *parent)
 {
        int error;
 
-       init_completion(&fs_info->kobj_unregister);
-       fs_info->super_kobj.kset = btrfs_kset;
-       error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
-                                    "%pU", fs_info->fsid);
+       init_completion(&fs_devs->kobj_unregister);
+       fs_devs->super_kobj.kset = btrfs_kset;
+       error = kobject_init_and_add(&fs_devs->super_kobj, &btrfs_ktype, NULL,
+                                    "%pU", fs_devs->fsid);
        return error;
 }
 
 int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
 {
        int error;
+       struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
+       struct kobject *super_kobj = &fs_devs->super_kobj;
 
-       error = btrfs_sysfs_add_fsid(fs_info, NULL);
+       error = btrfs_sysfs_add_fsid(fs_devs, NULL);
        if (error)
                return error;
 
        error = btrfs_kobj_add_device(fs_info, NULL);
        if (error) {
-               btrfs_sysfs_remove_fsid(fs_info);
+               btrfs_sysfs_remove_fsid(fs_devs);
                return error;
        }
 
-       error = sysfs_create_files(&fs_info->super_kobj, btrfs_attrs);
+       error = sysfs_create_files(super_kobj, btrfs_attrs);
        if (error) {
-               btrfs_sysfs_remove_fsid(fs_info);
+               btrfs_sysfs_remove_fsid(fs_devs);
                return error;
        }
 
-       error = sysfs_create_group(&fs_info->super_kobj,
+       error = sysfs_create_group(super_kobj,
                                   &btrfs_feature_attr_group);
        if (error)
                goto failure;
@@ -745,7 +755,7 @@ int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
                goto failure;
 
        fs_info->space_info_kobj = kobject_create_and_add("allocation",
-                                                 &fs_info->super_kobj);
+                                                 super_kobj);
        if (!fs_info->space_info_kobj) {
                error = -ENOMEM;
                goto failure;

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 174f5e1e00abfa533b1cb7483e44aae0f550e63a..39ff99e4b5a6653df3e9ba606683ac95c831ee07 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2252,7 +2252,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                 */
                snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
                                                root->fs_info->fsid);
-               if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
+               if (kobject_rename(&root->fs_info->fs_devices->super_kobj,
+                                                               fsid_buf))
                        goto error_trans;
        }
 

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index ebc31331a83746b23b4e99ac146b25fc03b31cc3..e9780e9e6d97f6961558fc5c38b34c65d9ccc80b 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -253,6 +253,11 @@ struct btrfs_fs_devices {
         * nonrot flag set
         */
        int rotating;
+
+       /* sysfs kobjects */
+       struct kobject super_kobj;
+       struct kobject *device_dir_kobj;
+       struct completion kobj_unregister;
 };
 
 #define BTRFS_BIO_INLINE_CSUM_SIZE     64