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authorMatthew Wilcox <willy@infradead.org>2018-12-06 00:37:03 +0300
committerMatthew Wilcox <willy@infradead.org>2019-01-07 05:24:43 +0300
commit02669b17a433c242a40f01f14b691c9c9d1f8a13 (patch)
tree8795a3a5f799d8a6482929bce982da7818d8e3c4 /include/linux/xarray.h
parent490fd30f859572ac97a51faa31860869744ba97b (diff)
downloadlinux-02669b17a433c242a40f01f14b691c9c9d1f8a13.tar.xz
XArray: Turn xa_init_flags into a static inline
A regular xa_init_flags() put all dynamically-initialised XArrays into the same locking class. That leads to lockdep believing that taking one XArray lock while holding another is a deadlock. It's possible to work around some of these situations with separate locking classes for irq/bh/regular XArrays, and SINGLE_DEPTH_NESTING, but that's ugly, and it doesn't work for all situations (where we have completely unrelated XArrays). Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'include/linux/xarray.h')
-rw-r--r--include/linux/xarray.h19
1 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index f492e21c4aa2..4cf3cd128689 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -286,7 +286,6 @@ struct xarray {
*/
#define DEFINE_XARRAY_ALLOC(name) DEFINE_XARRAY_FLAGS(name, XA_FLAGS_ALLOC)
-void xa_init_flags(struct xarray *, gfp_t flags);
void *xa_load(struct xarray *, unsigned long index);
void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t);
void *xa_erase(struct xarray *, unsigned long index);
@@ -304,6 +303,24 @@ unsigned int xa_extract(struct xarray *, void **dst, unsigned long start,
void xa_destroy(struct xarray *);
/**
+ * xa_init_flags() - Initialise an empty XArray with flags.
+ * @xa: XArray.
+ * @flags: XA_FLAG values.
+ *
+ * If you need to initialise an XArray with special flags (eg you need
+ * to take the lock from interrupt context), use this function instead
+ * of xa_init().
+ *
+ * Context: Any context.
+ */
+static inline void xa_init_flags(struct xarray *xa, gfp_t flags)
+{
+ spin_lock_init(&xa->xa_lock);
+ xa->xa_flags = flags;
+ xa->xa_head = NULL;
+}
+
+/**
* xa_init() - Initialise an empty XArray.
* @xa: XArray.
*