* PATCH [2.4.0test10]: Kiobuf#00, moving code
@ 2000-11-02 12:32 Stephen C. Tweedie
0 siblings, 0 replies; only message in thread
From: Stephen C. Tweedie @ 2000-11-02 12:32 UTC (permalink / raw)
To: Linus Torvalds; +Cc: Rik van Riel, Ingo Molnar, Stephen Tweedie, linux-mm
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Hi,
Patch 00 for kiobufs: moves a chunk of code from mm/memory.c to
fs/iobuf.c. The code concerned touches physical pages but has
absolutely nothing to do with virtual memory, so doesn't deserve to be
lumped with the map_user_kiobuf code.
--Stephen
[-- Attachment #2: 00-movecode.diff --]
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diff -ru linux-2.4.0-test10.orig/fs/iobuf.c linux-2.4.0-test10.kio.00/fs/iobuf.c
--- linux-2.4.0-test10.orig/fs/iobuf.c Mon Mar 13 13:26:09 2000
+++ linux-2.4.0-test10.kio.00/fs/iobuf.c Thu Nov 2 12:02:21 2000
@@ -9,6 +9,7 @@
#include <linux/iobuf.h>
#include <linux/malloc.h>
#include <linux/slab.h>
+#include <linux/pagemap.h>
static kmem_cache_t *kiobuf_cachep;
@@ -126,5 +127,131 @@
remove_wait_queue(&kiobuf->wait_queue, &wait);
}
+
+/*
+ * Unmap all of the pages referenced by a kiobuf. We release the pages,
+ * and unlock them if they were locked.
+ */
+
+void unmap_kiobuf (struct kiobuf *iobuf)
+{
+ int i;
+ struct page *map;
+
+ for (i = 0; i < iobuf->nr_pages; i++) {
+ map = iobuf->maplist[i];
+ if (map) {
+ if (iobuf->locked)
+ UnlockPage(map);
+ __free_page(map);
+ }
+ }
+
+ iobuf->nr_pages = 0;
+ iobuf->locked = 0;
+}
+
+
+/*
+ * Lock down all of the pages of a kiovec for IO.
+ *
+ * If any page is mapped twice in the kiovec, we return the error -EINVAL.
+ *
+ * The optional wait parameter causes the lock call to block until all
+ * pages can be locked if set. If wait==0, the lock operation is
+ * aborted if any locked pages are found and -EAGAIN is returned.
+ */
+
+int lock_kiovec(int nr, struct kiobuf *iovec[], int wait)
+{
+ struct kiobuf *iobuf;
+ int i, j;
+ struct page *page, **ppage;
+ int doublepage = 0;
+ int repeat = 0;
+
+ repeat:
+
+ for (i = 0; i < nr; i++) {
+ iobuf = iovec[i];
+
+ if (iobuf->locked)
+ continue;
+ iobuf->locked = 1;
+
+ ppage = iobuf->maplist;
+ for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
+ page = *ppage;
+ if (!page)
+ continue;
+
+ if (TryLockPage(page))
+ goto retry;
+ }
+ }
+
+ return 0;
+
+ retry:
+
+ /*
+ * We couldn't lock one of the pages. Undo the locking so far,
+ * wait on the page we got to, and try again.
+ */
+
+ unlock_kiovec(nr, iovec);
+ if (!wait)
+ return -EAGAIN;
+
+ /*
+ * Did the release also unlock the page we got stuck on?
+ */
+ if (!PageLocked(page)) {
+ /*
+ * If so, we may well have the page mapped twice
+ * in the IO address range. Bad news. Of
+ * course, it _might_ just be a coincidence,
+ * but if it happens more than once, chances
+ * are we have a double-mapped page.
+ */
+ if (++doublepage >= 3)
+ return -EINVAL;
+
+ /* Try again... */
+ wait_on_page(page);
+ }
+
+ if (++repeat < 16)
+ goto repeat;
+ return -EAGAIN;
+}
+
+/*
+ * Unlock all of the pages of a kiovec after IO.
+ */
+
+int unlock_kiovec(int nr, struct kiobuf *iovec[])
+{
+ struct kiobuf *iobuf;
+ int i, j;
+ struct page *page, **ppage;
+
+ for (i = 0; i < nr; i++) {
+ iobuf = iovec[i];
+
+ if (!iobuf->locked)
+ continue;
+ iobuf->locked = 0;
+
+ ppage = iobuf->maplist;
+ for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
+ page = *ppage;
+ if (!page)
+ continue;
+ UnlockPage(page);
+ }
+ }
+ return 0;
+}
diff -ru linux-2.4.0-test10.orig/include/linux/iobuf.h linux-2.4.0-test10.kio.00/include/linux/iobuf.h
--- linux-2.4.0-test10.orig/include/linux/iobuf.h Mon Mar 13 13:26:09 2000
+++ linux-2.4.0-test10.kio.00/include/linux/iobuf.h Thu Nov 2 12:02:43 2000
@@ -61,9 +61,6 @@
/* mm/memory.c */
int map_user_kiobuf(int rw, struct kiobuf *, unsigned long va, size_t len);
-void unmap_kiobuf(struct kiobuf *iobuf);
-int lock_kiovec(int nr, struct kiobuf *iovec[], int wait);
-int unlock_kiovec(int nr, struct kiobuf *iovec[]);
/* fs/iobuf.c */
@@ -75,6 +72,9 @@
void free_kiovec(int nr, struct kiobuf **);
int expand_kiobuf(struct kiobuf *, int);
void kiobuf_wait_for_io(struct kiobuf *);
+void unmap_kiobuf(struct kiobuf *iobuf);
+int lock_kiovec(int nr, struct kiobuf *iovec[], int wait);
+int unlock_kiovec(int nr, struct kiobuf *iovec[]);
/* fs/buffer.c */
diff -ru linux-2.4.0-test10.orig/mm/memory.c linux-2.4.0-test10.kio.00/mm/memory.c
--- linux-2.4.0-test10.orig/mm/memory.c Wed Nov 1 22:25:48 2000
+++ linux-2.4.0-test10.kio.00/mm/memory.c Thu Nov 2 11:51:41 2000
@@ -504,132 +504,6 @@
}
-/*
- * Unmap all of the pages referenced by a kiobuf. We release the pages,
- * and unlock them if they were locked.
- */
-
-void unmap_kiobuf (struct kiobuf *iobuf)
-{
- int i;
- struct page *map;
-
- for (i = 0; i < iobuf->nr_pages; i++) {
- map = iobuf->maplist[i];
- if (map) {
- if (iobuf->locked)
- UnlockPage(map);
- __free_page(map);
- }
- }
-
- iobuf->nr_pages = 0;
- iobuf->locked = 0;
-}
-
-
-/*
- * Lock down all of the pages of a kiovec for IO.
- *
- * If any page is mapped twice in the kiovec, we return the error -EINVAL.
- *
- * The optional wait parameter causes the lock call to block until all
- * pages can be locked if set. If wait==0, the lock operation is
- * aborted if any locked pages are found and -EAGAIN is returned.
- */
-
-int lock_kiovec(int nr, struct kiobuf *iovec[], int wait)
-{
- struct kiobuf *iobuf;
- int i, j;
- struct page *page, **ppage;
- int doublepage = 0;
- int repeat = 0;
-
- repeat:
-
- for (i = 0; i < nr; i++) {
- iobuf = iovec[i];
-
- if (iobuf->locked)
- continue;
- iobuf->locked = 1;
-
- ppage = iobuf->maplist;
- for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
- page = *ppage;
- if (!page)
- continue;
-
- if (TryLockPage(page))
- goto retry;
- }
- }
-
- return 0;
-
- retry:
-
- /*
- * We couldn't lock one of the pages. Undo the locking so far,
- * wait on the page we got to, and try again.
- */
-
- unlock_kiovec(nr, iovec);
- if (!wait)
- return -EAGAIN;
-
- /*
- * Did the release also unlock the page we got stuck on?
- */
- if (!PageLocked(page)) {
- /*
- * If so, we may well have the page mapped twice
- * in the IO address range. Bad news. Of
- * course, it _might_ just be a coincidence,
- * but if it happens more than once, chances
- * are we have a double-mapped page.
- */
- if (++doublepage >= 3)
- return -EINVAL;
-
- /* Try again... */
- wait_on_page(page);
- }
-
- if (++repeat < 16)
- goto repeat;
- return -EAGAIN;
-}
-
-/*
- * Unlock all of the pages of a kiovec after IO.
- */
-
-int unlock_kiovec(int nr, struct kiobuf *iovec[])
-{
- struct kiobuf *iobuf;
- int i, j;
- struct page *page, **ppage;
-
- for (i = 0; i < nr; i++) {
- iobuf = iovec[i];
-
- if (!iobuf->locked)
- continue;
- iobuf->locked = 0;
-
- ppage = iobuf->maplist;
- for (j = 0; j < iobuf->nr_pages; ppage++, j++) {
- page = *ppage;
- if (!page)
- continue;
- UnlockPage(page);
- }
- }
- return 0;
-}
-
static inline void zeromap_pte_range(pte_t * pte, unsigned long address,
unsigned long size, pgprot_t prot)
{
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2000-11-02 12:32 PATCH [2.4.0test10]: Kiobuf#00, moving code Stephen C. Tweedie
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