From: "Darrick J. Wong" <djwong@xxxxxxxxxx>
[ Upstream commit 9d720a5a658f5135861773f26e927449bef93d61 ]
Hoist these multiline conditionals into separate static inline helpers
to improve readability and set the stage for corruption fixes that will
be introduced in the next patch.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Xiao Yang <yangx.jy@xxxxxxxxxxx>
Signed-off-by: Leah Rumancik <leah.rumancik@xxxxxxxxx>
---
fs/xfs/libxfs/xfs_refcount.c | 129 ++++++++++++++++++++++++++++++-----
1 file changed, 113 insertions(+), 16 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
index 3f34bafe18dd..4408893333a6 100644
--- a/fs/xfs/libxfs/xfs_refcount.c
+++ b/fs/xfs/libxfs/xfs_refcount.c
@@ -815,11 +815,119 @@ xfs_refcount_find_right_extents(
/* Is this extent valid? */
static inline bool
xfs_refc_valid(
- struct xfs_refcount_irec *rc)
+ const struct xfs_refcount_irec *rc)
{
return rc->rc_startblock != NULLAGBLOCK;
}
+static inline bool
+xfs_refc_want_merge_center(
+ const struct xfs_refcount_irec *left,
+ const struct xfs_refcount_irec *cleft,
+ const struct xfs_refcount_irec *cright,
+ const struct xfs_refcount_irec *right,
+ bool cleft_is_cright,
+ enum xfs_refc_adjust_op adjust,
+ unsigned long long *ulenp)
+{
+ unsigned long long ulen = left->rc_blockcount;
+
+ /*
+ * To merge with a center record, both shoulder records must be
+ * adjacent to the record we want to adjust. This is only true if
+ * find_left and find_right made all four records valid.
+ */
+ if (!xfs_refc_valid(left) || !xfs_refc_valid(right) ||
+ !xfs_refc_valid(cleft) || !xfs_refc_valid(cright))
+ return false;
+
+ /* There must only be one record for the entire range. */
+ if (!cleft_is_cright)
+ return false;
+
+ /* The shoulder record refcounts must match the new refcount. */
+ if (left->rc_refcount != cleft->rc_refcount + adjust)
+ return false;
+ if (right->rc_refcount != cleft->rc_refcount + adjust)
+ return false;
+
+ /*
+ * The new record cannot exceed the max length. ulen is a ULL as the
+ * individual record block counts can be up to (u32 - 1) in length
+ * hence we need to catch u32 addition overflows here.
+ */
+ ulen += cleft->rc_blockcount + right->rc_blockcount;
+ if (ulen >= MAXREFCEXTLEN)
+ return false;
+
+ *ulenp = ulen;
+ return true;
+}
+
+static inline bool
+xfs_refc_want_merge_left(
+ const struct xfs_refcount_irec *left,
+ const struct xfs_refcount_irec *cleft,
+ enum xfs_refc_adjust_op adjust)
+{
+ unsigned long long ulen = left->rc_blockcount;
+
+ /*
+ * For a left merge, the left shoulder record must be adjacent to the
+ * start of the range. If this is true, find_left made left and cleft
+ * contain valid contents.
+ */
+ if (!xfs_refc_valid(left) || !xfs_refc_valid(cleft))
+ return false;
+
+ /* Left shoulder record refcount must match the new refcount. */
+ if (left->rc_refcount != cleft->rc_refcount + adjust)
+ return false;
+
+ /*
+ * The new record cannot exceed the max length. ulen is a ULL as the
+ * individual record block counts can be up to (u32 - 1) in length
+ * hence we need to catch u32 addition overflows here.
+ */
+ ulen += cleft->rc_blockcount;
+ if (ulen >= MAXREFCEXTLEN)
+ return false;
+
+ return true;
+}
+
+static inline bool
+xfs_refc_want_merge_right(
+ const struct xfs_refcount_irec *cright,
+ const struct xfs_refcount_irec *right,
+ enum xfs_refc_adjust_op adjust)
+{
+ unsigned long long ulen = right->rc_blockcount;
+
+ /*
+ * For a right merge, the right shoulder record must be adjacent to the
+ * end of the range. If this is true, find_right made cright and right
+ * contain valid contents.
+ */
+ if (!xfs_refc_valid(right) || !xfs_refc_valid(cright))
+ return false;
+
+ /* Right shoulder record refcount must match the new refcount. */
+ if (right->rc_refcount != cright->rc_refcount + adjust)
+ return false;
+
+ /*
+ * The new record cannot exceed the max length. ulen is a ULL as the
+ * individual record block counts can be up to (u32 - 1) in length
+ * hence we need to catch u32 addition overflows here.
+ */
+ ulen += cright->rc_blockcount;
+ if (ulen >= MAXREFCEXTLEN)
+ return false;
+
+ return true;
+}
+
/*
* Try to merge with any extents on the boundaries of the adjustment range.
*/
@@ -861,23 +969,15 @@ xfs_refcount_merge_extents(
(cleft.rc_blockcount == cright.rc_blockcount);
/* Try to merge left, cleft, and right. cleft must == cright. */
- ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount +
- right.rc_blockcount;
- if (xfs_refc_valid(&left) && xfs_refc_valid(&right) &&
- xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal &&
- left.rc_refcount == cleft.rc_refcount + adjust &&
- right.rc_refcount == cleft.rc_refcount + adjust &&
- ulen < MAXREFCEXTLEN) {
+ if (xfs_refc_want_merge_center(&left, &cleft, &cright, &right, cequal,
+ adjust, &ulen)) {
*shape_changed = true;
return xfs_refcount_merge_center_extents(cur, &left, &cleft,
&right, ulen, aglen);
}
/* Try to merge left and cleft. */
- ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount;
- if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) &&
- left.rc_refcount == cleft.rc_refcount + adjust &&
- ulen < MAXREFCEXTLEN) {
+ if (xfs_refc_want_merge_left(&left, &cleft, adjust)) {
*shape_changed = true;
error = xfs_refcount_merge_left_extent(cur, &left, &cleft,
agbno, aglen);
@@ -893,10 +993,7 @@ xfs_refcount_merge_extents(
}
/* Try to merge cright and right. */
- ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount;
- if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) &&
- right.rc_refcount == cright.rc_refcount + adjust &&
- ulen < MAXREFCEXTLEN) {
+ if (xfs_refc_want_merge_right(&cright, &right, adjust)) {
*shape_changed = true;
return xfs_refcount_merge_right_extent(cur, &right, &cright,
aglen);
--
2.44.0.769.g3c40516874-goog
