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| author | Matthew Wilcox <willy@infradead.org> | 2019-02-21 23:36:45 +0100 |
|---|---|---|
| committer | Matthew Wilcox <willy@infradead.org> | 2019-02-21 23:36:45 +0100 |
| commit | 2fbe967b3eb7466f679307b38564b8271c093241 (patch) | |
| tree | d5e97862217a0a89e538f073c7b66483438c2cca | |
| parent | XArray: Use xa_cmpxchg to implement xa_reserve (diff) | |
| download | linux-2fbe967b3eb7466f679307b38564b8271c093241.tar.xz linux-2fbe967b3eb7466f679307b38564b8271c093241.zip | |
XArray: Fix xa_erase of 2-byte aligned entries
xas_store() was interpreting the entry it found in the array as a node
entry if the bottom two bits had value 2. That's only true if either
the entry is in the root node or in a non-leaf node.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
| -rw-r--r-- | lib/test_xarray.c | 16 | ||||
| -rw-r--r-- | lib/xarray.c | 2 |
2 files changed, 16 insertions, 2 deletions
diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 52f8ecff8c0c..bc202d468a6b 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -1355,6 +1355,20 @@ static void check_align_1(struct xarray *xa, char *name) xa_destroy(xa); } +static void check_align_2(struct xarray *xa, char *name) +{ + int i; + + XA_BUG_ON(xa, !xa_empty(xa)); + + for (i = 0; i < 8; i++) { + XA_BUG_ON(xa, xa_store(xa, 0, name + i, GFP_KERNEL) != NULL); + xa_erase(xa, 0); + } + + XA_BUG_ON(xa, !xa_empty(xa)); +} + static noinline void check_align(struct xarray *xa) { char name[] = "Motorola 68000"; @@ -1363,7 +1377,7 @@ static noinline void check_align(struct xarray *xa) check_align_1(xa, name + 1); check_align_1(xa, name + 2); check_align_1(xa, name + 3); -// check_align_2(xa, name); + check_align_2(xa, name); } static LIST_HEAD(shadow_nodes); diff --git a/lib/xarray.c b/lib/xarray.c index 3f10198f00b7..2cc3798672f7 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -800,7 +800,7 @@ void *xas_store(struct xa_state *xas, void *entry) * entry is set to NULL. */ rcu_assign_pointer(*slot, entry); - if (xa_is_node(next)) + if (xa_is_node(next) && (!node || node->shift)) xas_free_nodes(xas, xa_to_node(next)); if (!node) break; |