[PATCH] vfs_btrfs: add qgroup-aware disk free support
Justin Maggard
jmaggard10 at gmail.com
Thu Jan 14 02:35:37 UTC 2016
On Wed, Jan 13, 2016 at 4:37 PM, Jeremy Allison <jra at samba.org> wrote:
> 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).
>
I pulled Uri's patchset into my local tree, and this patch still
applies and everything still builds without errors. Or was that not
the point? :-)
-Justin
> 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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