From 2c761270d5520dd84ab0b4e47c24d99ff8503c38 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 12 Jan 2010 17:39:16 +1100 Subject: [PATCH] lib: Introduce generic list_sort function There are two copies of list_sort() in the tree already, one in the DRM code, another in ubifs. Now XFS needs this as well. Create a generic list_sort() function from the ubifs version and convert existing users to it so we don't end up with yet another copy in the tree. Signed-off-by: Dave Chinner Acked-by: Dave Airlie Acked-by: Artem Bityutskiy Signed-off-by: Linus Torvalds --- drivers/gpu/drm/drm_modes.c | 90 ++------------------------------------ fs/ubifs/gc.c | 96 +---------------------------------------- include/linux/list_sort.h | 11 +++++ lib/Makefile | 2 +- lib/list_sort.c | 102 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 119 insertions(+), 182 deletions(-) create mode 100644 include/linux/list_sort.h create mode 100644 lib/list_sort.c diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 6d81a02..76d6339 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -1,9 +1,4 @@ /* - * The list_sort function is (presumably) licensed under the GPL (see the - * top level "COPYING" file for details). - * - * The remainder of this file is: - * * Copyright © 1997-2003 by The XFree86 Project, Inc. * Copyright © 2007 Dave Airlie * Copyright © 2007-2008 Intel Corporation @@ -36,6 +31,7 @@ */ #include +#include #include "drmP.h" #include "drm.h" #include "drm_crtc.h" @@ -855,6 +851,7 @@ EXPORT_SYMBOL(drm_mode_prune_invalid); /** * drm_mode_compare - compare modes for favorability + * @priv: unused * @lh_a: list_head for first mode * @lh_b: list_head for second mode * @@ -868,7 +865,7 @@ EXPORT_SYMBOL(drm_mode_prune_invalid); * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or * positive if @lh_b is better than @lh_a. */ -static int drm_mode_compare(struct list_head *lh_a, struct list_head *lh_b) +static int drm_mode_compare(void *priv, struct list_head *lh_a, struct list_head *lh_b) { struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head); struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head); @@ -885,85 +882,6 @@ static int drm_mode_compare(struct list_head *lh_a, struct list_head *lh_b) return diff; } -/* FIXME: what we don't have a list sort function? */ -/* list sort from Mark J Roberts (mjr@znex.org) */ -void list_sort(struct list_head *head, - int (*cmp)(struct list_head *a, struct list_head *b)) -{ - struct list_head *p, *q, *e, *list, *tail, *oldhead; - int insize, nmerges, psize, qsize, i; - - list = head->next; - list_del(head); - insize = 1; - for (;;) { - p = oldhead = list; - list = tail = NULL; - nmerges = 0; - - while (p) { - nmerges++; - q = p; - psize = 0; - for (i = 0; i < insize; i++) { - psize++; - q = q->next == oldhead ? NULL : q->next; - if (!q) - break; - } - - qsize = insize; - while (psize > 0 || (qsize > 0 && q)) { - if (!psize) { - e = q; - q = q->next; - qsize--; - if (q == oldhead) - q = NULL; - } else if (!qsize || !q) { - e = p; - p = p->next; - psize--; - if (p == oldhead) - p = NULL; - } else if (cmp(p, q) <= 0) { - e = p; - p = p->next; - psize--; - if (p == oldhead) - p = NULL; - } else { - e = q; - q = q->next; - qsize--; - if (q == oldhead) - q = NULL; - } - if (tail) - tail->next = e; - else - list = e; - e->prev = tail; - tail = e; - } - p = q; - } - - tail->next = list; - list->prev = tail; - - if (nmerges <= 1) - break; - - insize *= 2; - } - - head->next = list; - head->prev = list->prev; - list->prev->next = head; - list->prev = head; -} - /** * drm_mode_sort - sort mode list * @mode_list: list to sort @@ -975,7 +893,7 @@ void list_sort(struct list_head *head, */ void drm_mode_sort(struct list_head *mode_list) { - list_sort(mode_list, drm_mode_compare); + list_sort(NULL, mode_list, drm_mode_compare); } EXPORT_SYMBOL(drm_mode_sort); diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c index 618c270..e5a3d8e 100644 --- a/fs/ubifs/gc.c +++ b/fs/ubifs/gc.c @@ -54,6 +54,7 @@ */ #include +#include #include "ubifs.h" /* @@ -108,101 +109,6 @@ static int switch_gc_head(struct ubifs_info *c) } /** - * list_sort - sort a list. - * @priv: private data, passed to @cmp - * @head: the list to sort - * @cmp: the elements comparison function - * - * This function has been implemented by Mark J Roberts . It - * implements "merge sort" which has O(nlog(n)) complexity. The list is sorted - * in ascending order. - * - * The comparison function @cmp is supposed to return a negative value if @a is - * than @b, and a positive value if @a is greater than @b. If @a and @b are - * equivalent, then it does not matter what this function returns. - */ -static void list_sort(void *priv, struct list_head *head, - int (*cmp)(void *priv, struct list_head *a, - struct list_head *b)) -{ - struct list_head *p, *q, *e, *list, *tail, *oldhead; - int insize, nmerges, psize, qsize, i; - - if (list_empty(head)) - return; - - list = head->next; - list_del(head); - insize = 1; - for (;;) { - p = oldhead = list; - list = tail = NULL; - nmerges = 0; - - while (p) { - nmerges++; - q = p; - psize = 0; - for (i = 0; i < insize; i++) { - psize++; - q = q->next == oldhead ? NULL : q->next; - if (!q) - break; - } - - qsize = insize; - while (psize > 0 || (qsize > 0 && q)) { - if (!psize) { - e = q; - q = q->next; - qsize--; - if (q == oldhead) - q = NULL; - } else if (!qsize || !q) { - e = p; - p = p->next; - psize--; - if (p == oldhead) - p = NULL; - } else if (cmp(priv, p, q) <= 0) { - e = p; - p = p->next; - psize--; - if (p == oldhead) - p = NULL; - } else { - e = q; - q = q->next; - qsize--; - if (q == oldhead) - q = NULL; - } - if (tail) - tail->next = e; - else - list = e; - e->prev = tail; - tail = e; - } - p = q; - } - - tail->next = list; - list->prev = tail; - - if (nmerges <= 1) - break; - - insize *= 2; - } - - head->next = list; - head->prev = list->prev; - list->prev->next = head; - list->prev = head; -} - -/** * data_nodes_cmp - compare 2 data nodes. * @priv: UBIFS file-system description object * @a: first data node diff --git a/include/linux/list_sort.h b/include/linux/list_sort.h new file mode 100644 index 0000000..1a2df2e --- /dev/null +++ b/include/linux/list_sort.h @@ -0,0 +1,11 @@ +#ifndef _LINUX_LIST_SORT_H +#define _LINUX_LIST_SORT_H + +#include + +struct list_head; + +void list_sort(void *priv, struct list_head *head, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b)); +#endif diff --git a/lib/Makefile b/lib/Makefile index 911b25a..3b0b4a6 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ - string_helpers.o gcd.o + string_helpers.o gcd.o list_sort.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/list_sort.c b/lib/list_sort.c new file mode 100644 index 0000000..19d11e0 --- /dev/null +++ b/lib/list_sort.c @@ -0,0 +1,102 @@ +#include +#include +#include +#include +#include + +/** + * list_sort - sort a list. + * @priv: private data, passed to @cmp + * @head: the list to sort + * @cmp: the elements comparison function + * + * This function has been implemented by Mark J Roberts . It + * implements "merge sort" which has O(nlog(n)) complexity. The list is sorted + * in ascending order. + * + * The comparison function @cmp is supposed to return a negative value if @a is + * less than @b, and a positive value if @a is greater than @b. If @a and @b + * are equivalent, then it does not matter what this function returns. + */ +void list_sort(void *priv, struct list_head *head, + int (*cmp)(void *priv, struct list_head *a, + struct list_head *b)) +{ + struct list_head *p, *q, *e, *list, *tail, *oldhead; + int insize, nmerges, psize, qsize, i; + + if (list_empty(head)) + return; + + list = head->next; + list_del(head); + insize = 1; + for (;;) { + p = oldhead = list; + list = tail = NULL; + nmerges = 0; + + while (p) { + nmerges++; + q = p; + psize = 0; + for (i = 0; i < insize; i++) { + psize++; + q = q->next == oldhead ? NULL : q->next; + if (!q) + break; + } + + qsize = insize; + while (psize > 0 || (qsize > 0 && q)) { + if (!psize) { + e = q; + q = q->next; + qsize--; + if (q == oldhead) + q = NULL; + } else if (!qsize || !q) { + e = p; + p = p->next; + psize--; + if (p == oldhead) + p = NULL; + } else if (cmp(priv, p, q) <= 0) { + e = p; + p = p->next; + psize--; + if (p == oldhead) + p = NULL; + } else { + e = q; + q = q->next; + qsize--; + if (q == oldhead) + q = NULL; + } + if (tail) + tail->next = e; + else + list = e; + e->prev = tail; + tail = e; + } + p = q; + } + + tail->next = list; + list->prev = tail; + + if (nmerges <= 1) + break; + + insize *= 2; + } + + head->next = list; + head->prev = list->prev; + list->prev->next = head; + list->prev = head; +} + +EXPORT_SYMBOL(list_sort); -- 2.7.4