Btrfs: add qgroup inheritance

When creating a subvolume or snapshot, it is necessary
to initialize the qgroup account with a copy of some
other (tracking) qgroup. This patch adds parameters
to the ioctls to pass the information from which qgroup
to inherit.

Signed-off-by: Arne Jansen <sensille@gmx.net>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 55a7283a9e186ad3f266751ab0cf41145cb1756f..1dffd0adf975fcd2aa3c54f3bd991928384ec245 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -336,7 +336,8 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 static noinline int create_subvol(struct btrfs_root *root,
                                  struct dentry *dentry,
                                  char *name, int namelen,
-                                 u64 *async_transid)
+                                 u64 *async_transid,
+                                 struct btrfs_qgroup_inherit **inherit)
 {
        struct btrfs_trans_handle *trans;
        struct btrfs_key key;
@@ -368,6 +369,11 @@ static noinline int create_subvol(struct btrfs_root *root,
        if (IS_ERR(trans))
                return PTR_ERR(trans);
 
+       ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
+                                  inherit ? *inherit : NULL);
+       if (ret)
+               goto fail;
+
        leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
                                      0, objectid, NULL, 0, 0, 0);
        if (IS_ERR(leaf)) {
@@ -484,7 +490,7 @@ fail:
 
 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
                           char *name, int namelen, u64 *async_transid,
-                          bool readonly)
+                          bool readonly, struct btrfs_qgroup_inherit **inherit)
 {
        struct inode *inode;
        struct btrfs_pending_snapshot *pending_snapshot;
@@ -502,6 +508,10 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
        pending_snapshot->dentry = dentry;
        pending_snapshot->root = root;
        pending_snapshot->readonly = readonly;
+       if (inherit) {
+               pending_snapshot->inherit = *inherit;
+               *inherit = NULL;        /* take responsibility to free it */
+       }
 
        trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
        if (IS_ERR(trans)) {
@@ -635,7 +645,8 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 static noinline int btrfs_mksubvol(struct path *parent,
                                   char *name, int namelen,
                                   struct btrfs_root *snap_src,
-                                  u64 *async_transid, bool readonly)
+                                  u64 *async_transid, bool readonly,
+                                  struct btrfs_qgroup_inherit **inherit)
 {
        struct inode *dir  = parent->dentry->d_inode;
        struct dentry *dentry;
@@ -666,11 +677,11 @@ static noinline int btrfs_mksubvol(struct path *parent,
                goto out_up_read;
 
        if (snap_src) {
-               error = create_snapshot(snap_src, dentry,
-                                       name, namelen, async_transid, readonly);
+               error = create_snapshot(snap_src, dentry, name, namelen,
+                                       async_transid, readonly, inherit);
        } else {
                error = create_subvol(BTRFS_I(dir)->root, dentry,
-                                     name, namelen, async_transid);
+                                     name, namelen, async_transid, inherit);
        }
        if (!error)
                fsnotify_mkdir(dir, dentry);
@@ -1379,11 +1390,9 @@ out:
 }
 
 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
-                                                   char *name,
-                                                   unsigned long fd,
-                                                   int subvol,
-                                                   u64 *transid,
-                                                   bool readonly)
+                               char *name, unsigned long fd, int subvol,
+                               u64 *transid, bool readonly,
+                               struct btrfs_qgroup_inherit **inherit)
 {
        struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
        struct file *src_file;
@@ -1407,7 +1416,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 
        if (subvol) {
                ret = btrfs_mksubvol(&file->f_path, name, namelen,
-                                    NULL, transid, readonly);
+                                    NULL, transid, readonly, inherit);
        } else {
                struct inode *src_inode;
                src_file = fget(fd);
@@ -1426,7 +1435,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
                }
                ret = btrfs_mksubvol(&file->f_path, name, namelen,
                                     BTRFS_I(src_inode)->root,
-                                    transid, readonly);
+                                    transid, readonly, inherit);
                fput(src_file);
        }
 out:
@@ -1446,7 +1455,7 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
 
        ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
                                              vol_args->fd, subvol,
-                                             NULL, false);
+                                             NULL, false, NULL);
 
        kfree(vol_args);
        return ret;
@@ -1460,6 +1469,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
        u64 transid = 0;
        u64 *ptr = NULL;
        bool readonly = false;
+       struct btrfs_qgroup_inherit *inherit = NULL;
 
        vol_args = memdup_user(arg, sizeof(*vol_args));
        if (IS_ERR(vol_args))
@@ -1467,7 +1477,8 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
        vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
 
        if (vol_args->flags &
-           ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
+           ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
+             BTRFS_SUBVOL_QGROUP_INHERIT)) {
                ret = -EOPNOTSUPP;
                goto out;
        }
@@ -1476,10 +1487,21 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
                ptr = &transid;
        if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
                readonly = true;
+       if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
+               if (vol_args->size > PAGE_CACHE_SIZE) {
+                       ret = -EINVAL;
+                       goto out;
+               }
+               inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
+               if (IS_ERR(inherit)) {
+                       ret = PTR_ERR(inherit);
+                       goto out;
+               }
+       }
 
        ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
-                                             vol_args->fd, subvol,
-                                             ptr, readonly);
+                                             vol_args->fd, subvol, ptr,
+                                             readonly, &inherit);
 
        if (ret == 0 && ptr &&
            copy_to_user(arg +
@@ -1488,6 +1510,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
                ret = -EFAULT;
 out:
        kfree(vol_args);
+       kfree(inherit);
        return ret;
 }
 
@@ -3588,6 +3611,8 @@ long btrfs_ioctl(struct file *file, unsigned int
                return btrfs_ioctl_snap_create_v2(file, argp, 0);
        case BTRFS_IOC_SUBVOL_CREATE:
                return btrfs_ioctl_snap_create(file, argp, 1);
+       case BTRFS_IOC_SUBVOL_CREATE_V2:
+               return btrfs_ioctl_snap_create_v2(file, argp, 1);
        case BTRFS_IOC_SNAP_DESTROY:
                return btrfs_ioctl_snap_destroy(file, argp);
        case BTRFS_IOC_SUBVOL_GETFLAGS:

diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 9dd50c4656b3ede2bc2f2fa1a5bc1897826f6bc8..cdda57f1c240cefd94422179d17856e0b1e0050a 100644 (file)
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -32,6 +32,7 @@ struct btrfs_ioctl_vol_args {
 
 #define BTRFS_SUBVOL_CREATE_ASYNC      (1ULL << 0)
 #define BTRFS_SUBVOL_RDONLY            (1ULL << 1)
+#define BTRFS_SUBVOL_QGROUP_INHERIT    (1ULL << 2)
 #define BTRFS_FSID_SIZE 16
 #define BTRFS_UUID_SIZE 16
 
@@ -64,7 +65,13 @@ struct btrfs_ioctl_vol_args_v2 {
        __s64 fd;
        __u64 transid;
        __u64 flags;
-       __u64 unused[4];
+       union {
+               struct {
+                       __u64 size;
+                       struct btrfs_qgroup_inherit __user *qgroup_inherit;
+               };
+               __u64 unused[4];
+       };
        char name[BTRFS_SUBVOL_NAME_MAX + 1];
 };
 
@@ -382,6 +389,8 @@ struct btrfs_ioctl_qgroup_create_args {
 #define BTRFS_IOC_WAIT_SYNC  _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
 #define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
                                   struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_SUBVOL_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 24, \
+                                  struct btrfs_ioctl_vol_args_v2)
 #define BTRFS_IOC_SUBVOL_GETFLAGS _IOR(BTRFS_IOCTL_MAGIC, 25, __u64)
 #define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64)
 #define BTRFS_IOC_SCRUB _IOWR(BTRFS_IOCTL_MAGIC, 27, \

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index f1e29fbd5317aeea51880645b4f7d6589f8b0c99..127283913a42907edad5e486b3025e7a942cd57c 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -990,6 +990,14 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                }
        }
 
+       ret = btrfs_qgroup_inherit(trans, fs_info, root->root_key.objectid,
+                                  objectid, pending->inherit);
+       kfree(pending->inherit);
+       if (ret) {
+               pending->error = ret;
+               goto fail;
+       }
+
        key.objectid = objectid;
        key.offset = (u64)-1;
        key.type = BTRFS_ROOT_ITEM_KEY;

diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 2759e0572c5c242c4e6ff6bc961331af95bff111..cca315dcdfcd0e7fd93499cf30a40c113777d729 100644 (file)
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -73,6 +73,7 @@ struct btrfs_pending_snapshot {
        struct dentry *dentry;
        struct btrfs_root *root;
        struct btrfs_root *snap;
+       struct btrfs_qgroup_inherit *inherit;
        /* block reservation for the operation */
        struct btrfs_block_rsv block_rsv;
        /* extra metadata reseration for relocation */