diff options
| author | Matthew Wilcox <willy@infradead.org> | 2018-12-05 16:37:03 -0500 |
|---|---|---|
| committer | Matthew Wilcox <willy@infradead.org> | 2019-01-06 21:24:43 -0500 |
| commit | 02669b17a433c242a40f01f14b691c9c9d1f8a13 (patch) | |
| tree | 8795a3a5f799d8a6482929bce982da7818d8e3c4 /include/linux/xarray.h | |
| parent | 490fd30f859572ac97a51faa31860869744ba97b (diff) | |
| download | lwn-02669b17a433c242a40f01f14b691c9c9d1f8a13.tar.gz lwn-02669b17a433c242a40f01f14b691c9c9d1f8a13.zip | |
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.h | 19 |
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. * |