bcachefs: Reserve 8 bits in bch_reflink_p

Better repair for reflink pointers, as well as propagating new inode
options to indirect extents, are going to require a few extra bits
bch_reflink_p: so claim a few from the high end of the destination
index.

Also add some missing bounds checking.

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

diff --git a/fs/bcachefs/extent_update.c b/fs/bcachefs/extent_update.c
index 45c87c019f6b752fee0a82d250f8df74b1aeb520..6aac579a692aef0af66601786f65d98a02ad8a04 100644 (file)
--- a/fs/bcachefs/extent_update.c
+++ b/fs/bcachefs/extent_update.c
@@ -64,7 +64,7 @@ static int count_iters_for_insert(struct btree_trans *trans,
                break;
        case KEY_TYPE_reflink_p: {
                struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
-               u64 idx = le64_to_cpu(p.v->idx);
+               u64 idx = REFLINK_P_IDX(p.v);
                unsigned sectors = bpos_min(*end, p.k->p).offset -
                        bkey_start_offset(p.k);
                struct btree_iter iter;

diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index bc7cfdb6668742fb240c6eef1831e8367410eab3..98bb680b3860b0fef85941c5eab1e07370857e7c 100644 (file)
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -1495,7 +1495,7 @@ int bch2_cut_front_s(struct bpos where, struct bkey_s k)
        case KEY_TYPE_reflink_p: {
                struct bkey_s_reflink_p p = bkey_s_to_reflink_p(k);
 
-               le64_add_cpu(&p.v->idx, sub);
+               SET_REFLINK_P_IDX(p.v, REFLINK_P_IDX(p.v) + sub);
                break;
        }
        case KEY_TYPE_inline_data:

diff --git a/fs/bcachefs/io_read.c b/fs/bcachefs/io_read.c
index cbc3cc1f6d0334e0b22b733d618c32bf58afee8d..c700a95df89e3c8263ab689093358c5cd9f9d29e 100644 (file)
--- a/fs/bcachefs/io_read.c
+++ b/fs/bcachefs/io_read.c
@@ -754,17 +754,13 @@ int __bch2_read_indirect_extent(struct btree_trans *trans,
                                unsigned *offset_into_extent,
                                struct bkey_buf *orig_k)
 {
-       struct btree_iter iter;
-       struct bkey_s_c k;
-       u64 reflink_offset;
-       int ret;
+       struct bkey_i_reflink_p *p = bkey_i_to_reflink_p(orig_k->k);
+       u64 reflink_offset = REFLINK_P_IDX(&p->v) + *offset_into_extent;
 
-       reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) +
-               *offset_into_extent;
-
-       k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink,
+       struct btree_iter iter;
+       struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink,
                               POS(0, reflink_offset), 0);
-       ret = bkey_err(k);
+       int ret = bkey_err(k);
        if (ret)
                goto err;
 

diff --git a/fs/bcachefs/reflink.c b/fs/bcachefs/reflink.c
index 96cf50f4705d294f1e73676cd21917df25708a69..addaf5f746249d1baad248a229ad15429d48ff18 100644 (file)
--- a/fs/bcachefs/reflink.c
+++ b/fs/bcachefs/reflink.c
@@ -35,10 +35,10 @@ int bch2_reflink_p_validate(struct bch_fs *c, struct bkey_s_c k,
        struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
        int ret = 0;
 
-       bkey_fsck_err_on(le64_to_cpu(p.v->idx) < le32_to_cpu(p.v->front_pad),
+       bkey_fsck_err_on(REFLINK_P_IDX(p.v) < le32_to_cpu(p.v->front_pad),
                         c, reflink_p_front_pad_bad,
                         "idx < front_pad (%llu < %u)",
-                        le64_to_cpu(p.v->idx), le32_to_cpu(p.v->front_pad));
+                        REFLINK_P_IDX(p.v), le32_to_cpu(p.v->front_pad));
 fsck_err:
        return ret;
 }
@@ -49,7 +49,7 @@ void bch2_reflink_p_to_text(struct printbuf *out, struct bch_fs *c,
        struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
 
        prt_printf(out, "idx %llu front_pad %u back_pad %u",
-              le64_to_cpu(p.v->idx),
+              REFLINK_P_IDX(p.v),
               le32_to_cpu(p.v->front_pad),
               le32_to_cpu(p.v->back_pad));
 }
@@ -65,7 +65,7 @@ bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r
         */
        return false;
 
-       if (le64_to_cpu(l.v->idx) + l.k->size != le64_to_cpu(r.v->idx))
+       if (REFLINK_P_IDX(l.v) + l.k->size != REFLINK_P_IDX(r.v))
                return false;
 
        bch2_key_resize(l.k, l.k->size + r.k->size);
@@ -115,12 +115,12 @@ static int trans_trigger_reflink_p_segment(struct btree_trans *trans,
                u64 pad;
 
                pad = max_t(s64, le32_to_cpu(v->front_pad),
-                           le64_to_cpu(v->idx) - bkey_start_offset(&k->k));
+                           REFLINK_P_IDX(v) - bkey_start_offset(&k->k));
                BUG_ON(pad > U32_MAX);
                v->front_pad = cpu_to_le32(pad);
 
                pad = max_t(s64, le32_to_cpu(v->back_pad),
-                           k->k.p.offset - p.k->size - le64_to_cpu(v->idx));
+                           k->k.p.offset - p.k->size - REFLINK_P_IDX(v));
                BUG_ON(pad > U32_MAX);
                v->back_pad = cpu_to_le32(pad);
        }
@@ -147,8 +147,8 @@ static s64 gc_trigger_reflink_p_segment(struct btree_trans *trans,
        struct bch_fs *c = trans->c;
        struct reflink_gc *r;
        int add = !(flags & BTREE_TRIGGER_overwrite) ? 1 : -1;
-       u64 start = le64_to_cpu(p.v->idx);
-       u64 end = le64_to_cpu(p.v->idx) + p.k->size;
+       u64 start = REFLINK_P_IDX(p.v);
+       u64 end = start + p.k->size;
        u64 next_idx = end + le32_to_cpu(p.v->back_pad);
        s64 ret = 0;
        struct printbuf buf = PRINTBUF;
@@ -210,8 +210,8 @@ static int __trigger_reflink_p(struct btree_trans *trans,
        struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
        int ret = 0;
 
-       u64 idx = le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
-       u64 end = le64_to_cpu(p.v->idx) + p.k->size + le32_to_cpu(p.v->back_pad);
+       u64 idx = REFLINK_P_IDX(p.v) - le32_to_cpu(p.v->front_pad);
+       u64 end = REFLINK_P_IDX(p.v) + p.k->size + le32_to_cpu(p.v->back_pad);
 
        if (flags & BTREE_TRIGGER_transactional) {
                while (idx < end && !ret)
@@ -258,7 +258,16 @@ int bch2_trigger_reflink_p(struct btree_trans *trans,
 int bch2_reflink_v_validate(struct bch_fs *c, struct bkey_s_c k,
                            enum bch_validate_flags flags)
 {
-       return bch2_bkey_ptrs_validate(c, k, flags);
+       int ret = 0;
+
+       bkey_fsck_err_on(bkey_gt(k.k->p, POS(0, REFLINK_P_IDX_MAX)),
+                        c, reflink_v_pos_bad,
+                        "indirect extent above maximum position 0:%llu",
+                        REFLINK_P_IDX_MAX);
+
+       ret = bch2_bkey_ptrs_validate(c, k, flags);
+fsck_err:
+       return ret;
 }
 
 void bch2_reflink_v_to_text(struct printbuf *out, struct bch_fs *c,
@@ -358,6 +367,14 @@ static int bch2_make_extent_indirect(struct btree_trans *trans,
        if (ret)
                goto err;
 
+       /*
+        * XXX: we're assuming that 56 bits will be enough for the life of the
+        * filesystem: we need to implement wraparound, with a cursor in the
+        * logged ops btree:
+        */
+       if (bkey_ge(reflink_iter.pos, POS(0, REFLINK_P_IDX_MAX - orig->k.size)))
+               return -ENOSPC;
+
        r_v = bch2_trans_kmalloc(trans, sizeof(__le64) + bkey_bytes(&orig->k));
        ret = PTR_ERR_OR_ZERO(r_v);
        if (ret)
@@ -394,7 +411,7 @@ static int bch2_make_extent_indirect(struct btree_trans *trans,
        memset(&r_p->v, 0, sizeof(r_p->v));
 #endif
 
-       r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
+       SET_REFLINK_P_IDX(&r_p->v, bkey_start_offset(&r_v->k));
 
        ret = bch2_trans_update(trans, extent_iter, &r_p->k_i,
                                BTREE_UPDATE_internal_snapshot_node);
@@ -533,11 +550,11 @@ s64 bch2_remap_range(struct bch_fs *c,
                        struct bkey_i_reflink_p *dst_p =
                                bkey_reflink_p_init(new_dst.k);
 
-                       u64 offset = le64_to_cpu(src_p.v->idx) +
+                       u64 offset = REFLINK_P_IDX(src_p.v) +
                                (src_want.offset -
                                 bkey_start_offset(src_k.k));
 
-                       dst_p->v.idx = cpu_to_le64(offset);
+                       SET_REFLINK_P_IDX(&dst_p->v, offset);
                } else {
                        BUG();
                }

diff --git a/fs/bcachefs/reflink_format.h b/fs/bcachefs/reflink_format.h
index 6772eebb1fc6685faf4729ebbd1b726e1b4d922e..0d8de13b9ddf7335c0d4b0bcb98d438e59c1536a 100644 (file)
--- a/fs/bcachefs/reflink_format.h
+++ b/fs/bcachefs/reflink_format.h
@@ -4,7 +4,7 @@
 
 struct bch_reflink_p {
        struct bch_val          v;
-       __le64                  idx;
+       __le64                  idx_flags;
        /*
         * A reflink pointer might point to an indirect extent which is then
         * later split (by copygc or rebalance). If we only pointed to part of
@@ -17,6 +17,8 @@ struct bch_reflink_p {
        __le32                  back_pad;
 } __packed __aligned(8);
 
+LE64_BITMASK(REFLINK_P_IDX,    struct bch_reflink_p, idx_flags,  0, 56);
+
 struct bch_reflink_v {
        struct bch_val          v;
        __le64                  refcount;