diff options
| author | Matthew Wilcox <willy@infradead.org> | 2018-11-05 16:15:56 -0500 |
|---|---|---|
| committer | Matthew Wilcox <willy@infradead.org> | 2018-11-05 16:38:09 -0500 |
| commit | d9c480435add8257f9069941f0e6196647f6d746 (patch) | |
| tree | 8e46a69188df371b24c83cf2181d42971336344b /lib | |
| parent | 611f318637daa5710a1d7a0e7dc6cda23914094a (diff) | |
| download | lwn-d9c480435add8257f9069941f0e6196647f6d746.tar.gz lwn-d9c480435add8257f9069941f0e6196647f6d746.zip | |
XArray: Handle NULL pointers differently for allocation
For allocating XArrays, it makes sense to distinguish beteen erasing an
entry and storing NULL. Storing NULL keeps the index allocated with a
NULL pointer associated with it while xa_erase() frees the index. Some
existing IDR users rely on this ability.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/xarray.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/lib/xarray.c b/lib/xarray.c index a9d28013f9dc..c3e2084aa313 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1382,10 +1382,12 @@ void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) if (WARN_ON_ONCE(xa_is_internal(entry))) return XA_ERROR(-EINVAL); + if (xa_track_free(xa) && !entry) + entry = XA_ZERO_ENTRY; do { curr = xas_store(&xas, entry); - if (xa_track_free(xa) && entry) + if (xa_track_free(xa)) xas_clear_mark(&xas, XA_FREE_MARK); } while (__xas_nomem(&xas, gfp)); @@ -1446,6 +1448,8 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index, if (WARN_ON_ONCE(xa_is_internal(entry))) return XA_ERROR(-EINVAL); + if (xa_track_free(xa) && !entry) + entry = XA_ZERO_ENTRY; do { curr = xas_load(&xas); @@ -1453,7 +1457,7 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index, curr = NULL; if (curr == old) { xas_store(&xas, entry); - if (xa_track_free(xa) && entry) + if (xa_track_free(xa)) xas_clear_mark(&xas, XA_FREE_MARK); } } while (__xas_nomem(&xas, gfp)); @@ -1487,8 +1491,11 @@ int __xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp) do { curr = xas_load(&xas); - if (!curr) + if (!curr) { xas_store(&xas, XA_ZERO_ENTRY); + if (xa_track_free(xa)) + xas_clear_mark(&xas, XA_FREE_MARK); + } } while (__xas_nomem(&xas, gfp)); return xas_error(&xas); |