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authorLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 19:47:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 19:47:50 -0700
commit56847d857cb0c3ee78c22ce776a26f88d9ffd4d4 (patch)
treea85bcf204a53e45d26f6a3984f16ddd525eef3e7 /lib/idr.c
parent191a712090bb8a10e6f129360eeed2d68f3d4c9a (diff)
parent8d564368a9a3197f43e56dadf4a18c5738849f94 (diff)
Merge branch 'akpm' (incoming from Andrew)
Merge second batch of fixes from Andrew Morton: - various misc bits - some printk updates - a new "SRAM" driver. - MAINTAINERS updates - the backlight driver queue - checkpatch updates - a few init/ changes - a huge number of drivers/rtc changes - fatfs updates - some lib/idr.c work - some renaming of the random driver interfaces * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (285 commits) net: rename random32 to prandom net/core: remove duplicate statements by do-while loop net/core: rename random32() to prandom_u32() net/netfilter: rename random32() to prandom_u32() net/sched: rename random32() to prandom_u32() net/sunrpc: rename random32() to prandom_u32() scsi: rename random32() to prandom_u32() lguest: rename random32() to prandom_u32() uwb: rename random32() to prandom_u32() video/uvesafb: rename random32() to prandom_u32() mmc: rename random32() to prandom_u32() drbd: rename random32() to prandom_u32() kernel/: rename random32() to prandom_u32() mm/: rename random32() to prandom_u32() lib/: rename random32() to prandom_u32() x86: rename random32() to prandom_u32() x86: pageattr-test: remove srandom32 call uuid: use prandom_bytes() raid6test: use prandom_bytes() sctp: convert sctp_assoc_set_id() to use idr_alloc_cyclic() ...
Diffstat (limited to 'lib/idr.c')
-rw-r--r--lib/idr.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/lib/idr.c b/lib/idr.c
index 322e2816f2f..cca4b9302a7 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -495,6 +495,33 @@ int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask)
}
EXPORT_SYMBOL_GPL(idr_alloc);
+/**
+ * idr_alloc_cyclic - allocate new idr entry in a cyclical fashion
+ * @idr: the (initialized) idr
+ * @ptr: pointer to be associated with the new id
+ * @start: the minimum id (inclusive)
+ * @end: the maximum id (exclusive, <= 0 for max)
+ * @gfp_mask: memory allocation flags
+ *
+ * Essentially the same as idr_alloc, but prefers to allocate progressively
+ * higher ids if it can. If the "cur" counter wraps, then it will start again
+ * at the "start" end of the range and allocate one that has already been used.
+ */
+int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end,
+ gfp_t gfp_mask)
+{
+ int id;
+
+ id = idr_alloc(idr, ptr, max(start, idr->cur), end, gfp_mask);
+ if (id == -ENOSPC)
+ id = idr_alloc(idr, ptr, start, end, gfp_mask);
+
+ if (likely(id >= 0))
+ idr->cur = id + 1;
+ return id;
+}
+EXPORT_SYMBOL(idr_alloc_cyclic);
+
static void idr_remove_warning(int id)
{
printk(KERN_WARNING