[PATCH] vfs_btrfs: add qgroup-aware disk free support
Jeremy Allison
jra at samba.org
Thu Jan 14 00:37:59 UTC 2016
On Wed, Jan 13, 2016 at 04:27:48PM -0800, Justin Maggard wrote:
> Add support for qgroup-aware representation of disk free statistics to
> vfs_btrfs. If max_rfer has been defined on the subvolume, use metrics
> from qgroups to represent disk free.
>
> This can be disabled by setting "btrfs:qgroup dfree" to false in smb.conf.
Justin, can you rebase this on top of the dfree/quota changes
that Uri has made recently (not in the tree yet, but the
patches are available on the list).
Cheers,
Jeremy.
> Signed-off-by: Justin Maggard <jmaggard at netgear.com>
> ---
> source3/modules/vfs_btrfs.c | 170 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 170 insertions(+)
>
> diff --git a/source3/modules/vfs_btrfs.c b/source3/modules/vfs_btrfs.c
> index bd95637..435f08f 100644
> --- a/source3/modules/vfs_btrfs.c
> +++ b/source3/modules/vfs_btrfs.c
> @@ -50,7 +50,13 @@ static uint32_t btrfs_fs_capabilities(struct vfs_handle_struct *handle,
>
> #define BTRFS_SUBVOL_RDONLY (1ULL << 1)
> #define BTRFS_SUBVOL_NAME_MAX 4039
> +#define BTRFS_INO_LOOKUP_PATH_MAX 4080
> #define BTRFS_PATH_NAME_MAX 4087
> +#define BTRFS_FIRST_FREE_OBJECTID 256ULL
> +#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
> +#define BTRFS_QGROUP_INFO_KEY 242
> +#define BTRFS_QGROUP_LIMIT_KEY 244
> +#define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key))
> struct btrfs_ioctl_vol_args_v2 {
> int64_t fd;
> uint64_t transid;
> @@ -70,11 +76,65 @@ struct btrfs_ioctl_clone_range_args {
> uint64_t dest_offset;
> };
>
> +struct btrfs_ioctl_search_key {
> + uint64_t tree_id;
> + uint64_t min_objectid;
> + uint64_t max_objectid;
> + uint64_t min_offset;
> + uint64_t max_offset;
> + uint64_t min_transid;
> + uint64_t max_transid;
> + uint32_t min_type;
> + uint32_t max_type;
> + uint32_t nr_items;
> + uint32_t unused;
> + uint64_t unused1[4];
> +};
> +
> +struct btrfs_ioctl_search_header {
> + uint64_t transid;
> + uint64_t objectid;
> + uint64_t offset;
> + uint32_t type;
> + uint32_t len;
> +} __attribute__((may_alias));
> +
> +struct btrfs_ioctl_search_args {
> + struct btrfs_ioctl_search_key key;
> + char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
> +};
> +
> +struct btrfs_ioctl_ino_lookup_args {
> + uint64_t treeid;
> + uint64_t objectid;
> + char name[BTRFS_INO_LOOKUP_PATH_MAX];
> +};
> +
> +struct btrfs_qgroup_info_item {
> + uint64_t generation;
> + uint64_t referenced;
> + uint64_t referenced_compressed;
> + uint64_t exclusive;
> + uint64_t exclusive_compressed;
> +} __attribute__ ((__packed__, may_alias));
> +
> +struct btrfs_qgroup_limit_item {
> + uint64_t flags;
> + uint64_t max_referenced;
> + uint64_t max_exclusive;
> + uint64_t rsv_referenced;
> + uint64_t rsv_exclusive;
> +} __attribute__ ((__packed__, may_alias));
> +
> #define BTRFS_IOCTL_MAGIC 0x94
> #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
> struct btrfs_ioctl_clone_range_args)
> #define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
> struct btrfs_ioctl_vol_args)
> +#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
> + struct btrfs_ioctl_search_args)
> +#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
> + struct btrfs_ioctl_ino_lookup_args)
> #define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
> struct btrfs_ioctl_vol_args_v2)
>
> @@ -665,6 +725,115 @@ static NTSTATUS btrfs_snap_delete(struct vfs_handle_struct *handle,
> return NT_STATUS_OK;
> }
>
> +static uint64_t btrfs_get_path_rootid(int fd)
> +{
> + int ret;
> + struct btrfs_ioctl_ino_lookup_args args;
> +
> + memset(&args, 0, sizeof(args));
> + args.objectid = BTRFS_FIRST_FREE_OBJECTID;
> +
> + ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
> + if (ret < 0) {
> + return (uint64_t)ret;
> + }
> + return args.treeid;
> +}
> +
> +static int qgroup_search(int fd, uint64_t *used, uint64_t *quota, uint64_t qgroupid)
> +{
> + struct btrfs_ioctl_search_args args;
> + struct btrfs_ioctl_search_key *sk = &args.key;
> + struct btrfs_ioctl_search_header *sh;
> + struct btrfs_qgroup_info_item *info;
> + struct btrfs_qgroup_limit_item *limit;
> + unsigned long off = 0;
> + unsigned int i;
> + int ret;
> +
> + memset(&args, 0, sizeof(args));
> + sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
> + sk->min_type = BTRFS_QGROUP_INFO_KEY;
> + sk->max_type = BTRFS_QGROUP_LIMIT_KEY;
> + sk->max_objectid = (uint64_t)-1;
> + sk->max_offset = (uint64_t)-1;
> + sk->max_transid = (uint64_t)-1;
> + sk->nr_items = 4096;
> +
> + while (true) {
> + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
> + if (ret < 0) {
> + return ret;
> + }
> + if (sk->nr_items == 0) {
> + break;
> + }
> + off = 0;
> + for (i = 0; i < sk->nr_items; i++) {
> + sh = (struct btrfs_ioctl_search_header *)(args.buf +
> + off);
> + off += sizeof(*sh);
> +
> + if (sh->type == BTRFS_QGROUP_INFO_KEY) {
> + info = (struct btrfs_qgroup_info_item *)
> + (args.buf + off);
> + if (sh->offset == qgroupid) {
> + *used = BVAL(&info->referenced, 0);
> + }
> + } else if (sh->type == BTRFS_QGROUP_LIMIT_KEY) {
> + limit = (struct btrfs_qgroup_limit_item *)
> + (args.buf + off);
> + if (sh->offset == qgroupid) {
> + *quota = BVAL(&limit->max_referenced, 0);
> + }
> + } else {
> + return 0;
> + }
> +
> + off += sh->len;
> + sk->min_type = sh->type;
> + sk->min_offset = sh->offset;
> + sk->min_objectid = sh->objectid;
> + }
> + sk->nr_items = 4096;
> + if (sk->min_offset < (uint64_t)-1) {
> + sk->min_offset++;
> + } else {
> + break;
> + }
> + }
> + return 0;
> +}
> +
> +static uint64_t btrfs_disk_free(vfs_handle_struct *handle,
> + const char *path, uint64_t *bsize,
> + uint64_t *dfree, uint64_t *dsize)
> +{
> + int ret = -1, fd;
> + uint64_t used = UINT64_MAX, quota = 0, id;
> +
> + if (lp_parm_bool(-1, "btrfs", "qgroup dfree", true)) {
> + become_root();
> + if ((fd = open(path, 0)) >= 0) {
> + id = btrfs_get_path_rootid(fd);
> + if (id != (uint64_t)-1) {
> + ret = qgroup_search(fd, &used, "a, id);
> + }
> + close(fd);
> + }
> + unbecome_root();
> + }
> + if (ret || used == UINT64_MAX || !quota) {
> + return SMB_VFS_NEXT_DISK_FREE(handle, path,
> + bsize, dfree, dsize);
> + }
> + *bsize = 4096;
> + *dfree = (quota - used)/4096;
> + *dsize = quota/4096;
> + return (quota - used)/1024;
> +}
> +
> +
> static struct vfs_fn_pointers btrfs_fns = {
> .fs_capabilities_fn = btrfs_fs_capabilities,
> .copy_chunk_send_fn = btrfs_copy_chunk_send,
> @@ -674,6 +843,7 @@ static struct vfs_fn_pointers btrfs_fns = {
> .snap_check_path_fn = btrfs_snap_check_path,
> .snap_create_fn = btrfs_snap_create,
> .snap_delete_fn = btrfs_snap_delete,
> + .disk_free_fn = btrfs_disk_free,
> };
>
> NTSTATUS vfs_btrfs_init(void);
> --
> 2.7.0
>
>
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