bcachefs: Reflink now respects quotas

This adds a new helper, quota_reserve_range(), which takes a quota
reservation for unallocated blocks in a given file range, and uses it in
bch2_remap_file_range().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c
index 3cb542f0d8c7f90aeaf3e10ef39c9d086510aadb..f5517c31f120ca624cb3b5643e4e3393e78f98bc 100644 (file)
--- a/fs/bcachefs/fs-io.c
+++ b/fs/bcachefs/fs-io.c
@@ -150,7 +150,7 @@ static void bch2_quota_reservation_put(struct bch_fs *c,
 static int bch2_quota_reservation_add(struct bch_fs *c,
                                      struct bch_inode_info *inode,
                                      struct quota_res *res,
-                                     unsigned sectors,
+                                     u64 sectors,
                                      bool check_enospc)
 {
        int ret;
@@ -3132,6 +3132,55 @@ long bch2_fallocate_dispatch(struct file *file, int mode,
        return bch2_err_class(ret);
 }
 
+static int quota_reserve_range(struct bch_inode_info *inode,
+                              struct quota_res *res,
+                              u64 start, u64 end)
+{
+       struct bch_fs *c = inode->v.i_sb->s_fs_info;
+       struct btree_trans trans;
+       struct btree_iter iter;
+       struct bkey_s_c k;
+       u32 snapshot;
+       u64 sectors = end - start;
+       u64 pos = start;
+       int ret;
+
+       bch2_trans_init(&trans, c, 0, 0);
+retry:
+       bch2_trans_begin(&trans);
+
+       ret = bch2_subvolume_get_snapshot(&trans, inode->ei_subvol, &snapshot);
+       if (ret)
+               goto err;
+
+       bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+                            SPOS(inode->v.i_ino, pos, snapshot), 0);
+
+       while (!(ret = btree_trans_too_many_iters(&trans)) &&
+              (k = bch2_btree_iter_peek_upto(&iter, POS(inode->v.i_ino, end - 1))).k &&
+              !(ret = bkey_err(k))) {
+               if (bkey_extent_is_allocation(k.k)) {
+                       u64 s = min(end, k.k->p.offset) -
+                               max(start, bkey_start_offset(k.k));
+                       BUG_ON(s > sectors);
+                       sectors -= s;
+               }
+               bch2_btree_iter_advance(&iter);
+       }
+       pos = iter.pos.offset;
+       bch2_trans_iter_exit(&trans, &iter);
+err:
+       if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+               goto retry;
+
+       bch2_trans_exit(&trans);
+
+       if (ret)
+               return ret;
+
+       return bch2_quota_reservation_add(c, inode, res, sectors, true);
+}
+
 loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
                             struct file *file_dst, loff_t pos_dst,
                             loff_t len, unsigned remap_flags)
@@ -3139,6 +3188,7 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
        struct bch_inode_info *src = file_bch_inode(file_src);
        struct bch_inode_info *dst = file_bch_inode(file_dst);
        struct bch_fs *c = src->v.i_sb->s_fs_info;
+       struct quota_res quota_res = { 0 };
        s64 i_sectors_delta = 0;
        u64 aligned_len;
        loff_t ret = 0;
@@ -3159,8 +3209,6 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
 
        bch2_lock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
 
-       file_update_time(file_dst);
-
        inode_dio_wait(&src->v);
        inode_dio_wait(&dst->v);
 
@@ -3177,6 +3225,13 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
        if (ret)
                goto err;
 
+       ret = quota_reserve_range(dst, &quota_res, pos_dst >> 9,
+                                 (pos_dst + aligned_len) >> 9);
+       if (ret)
+               goto err;
+
+       file_update_time(file_dst);
+
        mark_pagecache_unallocated(src, pos_src >> 9,
                                   (pos_src + aligned_len) >> 9);
 
@@ -3193,8 +3248,7 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
         */
        ret = min((u64) ret << 9, (u64) len);
 
-       /* XXX get a quota reservation */
-       i_sectors_acct(c, dst, NULL, i_sectors_delta);
+       i_sectors_acct(c, dst, &quota_res, i_sectors_delta);
 
        spin_lock(&dst->v.i_lock);
        if (pos_dst + ret > dst->v.i_size)
@@ -3205,6 +3259,7 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
            IS_SYNC(file_inode(file_dst)))
                ret = bch2_flush_inode(c, inode_inum(dst));
 err:
+       bch2_quota_reservation_put(c, dst, &quota_res);
        bch2_unlock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
 
        return bch2_err_class(ret);