Pull from: http://gkernel.bkbits.net/vm-2.5
---------------------------------------------------------------------------
ChangeSet@1.230, 2002-02-08 18:11:31-05:00, jgarzik@rum.normnet.org
After Al Viro's recent swapfile cleanup, the swap_device member of
swap_info_struct became pretty much superfluous. As we are minimizing
kdev_t usage anyway, I took the opportunity to remove swap_device
member, and replace the remaining usages with SWP_BLOCKDEV bit flag.
Adding SWP_BLOCKDEV in turn motivated a small cleanup of the
SWP_xxx bit flags and their usage.
Patch has been in light testing for a couple weeks, and
has been glanced at by Al. "looks sane"
include/linux/swap.h | 9 ++++++---
mm/swapfile.c | 33 ++++++++++++++++++---------------
2 files changed, 24 insertions(+), 18 deletions(-)
---------------------------------------------------------------------------
diff -Nru a/include/linux/swap.h b/include/linux/swap.h
--- a/include/linux/swap.h Fri Feb 8 19:10:16 2002
+++ b/include/linux/swap.h Fri Feb 8 19:10:16 2002
@@ -50,8 +50,12 @@
#include <asm/atomic.h>
-#define SWP_USED 1
-#define SWP_WRITEOK 3
+enum {
+ SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
+ SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
+ SWP_BLOCKDEV = (1 << 2), /* is this swap a block device? */
+ SWP_ACTIVE = (SWP_USED | SWP_WRITEOK),
+};
#define SWAP_CLUSTER_MAX 32
@@ -63,7 +67,6 @@
*/
struct swap_info_struct {
unsigned int flags;
- kdev_t swap_device;
spinlock_t sdev_lock;
struct file *swap_file;
unsigned short * swap_map;
diff -Nru a/mm/swapfile.c b/mm/swapfile.c
--- a/mm/swapfile.c Fri Feb 8 19:10:16 2002
+++ b/mm/swapfile.c Fri Feb 8 19:10:16 2002
@@ -114,7 +114,7 @@
while (1) {
p = &swap_info[type];
- if ((p->flags & SWP_WRITEOK) == SWP_WRITEOK) {
+ if ((p->flags & SWP_ACTIVE) == SWP_ACTIVE) {
swap_device_lock(p);
offset = scan_swap_map(p);
swap_device_unlock(p);
@@ -729,7 +729,7 @@
swap_list_lock();
for (type = swap_list.head; type >= 0; type = swap_info[type].next) {
p = swap_info + type;
- if ((p->flags & SWP_WRITEOK) == SWP_WRITEOK) {
+ if ((p->flags & SWP_ACTIVE) == SWP_ACTIVE) {
if (p->swap_file->f_dentry == nd.dentry)
break;
}
@@ -752,7 +752,7 @@
}
nr_swap_pages -= p->pages;
total_swap_pages -= p->pages;
- p->flags = SWP_USED;
+ p->flags &= ~SWP_WRITEOK;
swap_list_unlock();
unlock_kernel();
err = try_to_unuse(type);
@@ -770,7 +770,7 @@
swap_info[prev].next = p - swap_info;
nr_swap_pages += p->pages;
total_swap_pages += p->pages;
- p->flags = SWP_WRITEOK;
+ p->flags |= SWP_WRITEOK;
swap_list_unlock();
goto out_dput;
}
@@ -778,7 +778,6 @@
swap_device_lock(p);
swap_file = p->swap_file;
p->swap_file = NULL;
- p->swap_device = NODEV;
p->max = 0;
swap_map = p->swap_map;
p->swap_map = NULL;
@@ -822,7 +821,8 @@
}
len += sprintf(buf + len, "%-39s %s\t%d\t%d\t%d\n",
path,
- !kdev_none(ptr->swap_device) ? "partition" : "file\t",
+ (ptr->flags & SWP_BLOCKDEV) ?
+ "partition" : "file\t",
ptr->pages << (PAGE_SHIFT - 10),
usedswap << (PAGE_SHIFT - 10),
ptr->prio);
@@ -837,9 +837,10 @@
int i;
for (i = 0 ; i < nr_swapfiles ; i++, ptr++) {
- if (ptr->flags & SWP_USED)
- if (kdev_same(ptr->swap_device, dev))
- return 1;
+ if ((ptr->flags & SWP_USED) &&
+ (ptr->flags & SWP_BLOCKDEV) &&
+ (kdev_same(ptr->swap_file->f_dentry->d_inode->i_rdev, dev)))
+ return 1;
}
return 0;
}
@@ -883,7 +884,6 @@
nr_swapfiles = type+1;
p->flags = SWP_USED;
p->swap_file = NULL;
- p->swap_device = NODEV;
p->swap_map = NULL;
p->lowest_bit = 0;
p->highest_bit = 0;
@@ -911,8 +911,10 @@
error = -EINVAL;
if (S_ISBLK(swap_file->f_dentry->d_inode->i_mode)) {
- p->swap_device = swap_file->f_dentry->d_inode->i_rdev;
- set_blocksize(p->swap_device, PAGE_SIZE);
+ error = set_blocksize(swap_file->f_dentry->d_inode->i_rdev,
+ PAGE_SIZE);
+ if (error < 0)
+ goto bad_swap;
} else if (!S_ISREG(swap_file->f_dentry->d_inode->i_mode))
goto bad_swap;
@@ -1035,7 +1037,9 @@
swap_list_lock();
swap_device_lock(p);
p->max = maxpages;
- p->flags = SWP_WRITEOK;
+ p->flags = SWP_ACTIVE;
+ if (S_ISBLK(swap_file->f_dentry->d_inode->i_mode))
+ p->flags |= SWP_BLOCKDEV;
p->pages = nr_good_pages;
nr_swap_pages += nr_good_pages;
total_swap_pages += nr_good_pages;
@@ -1064,7 +1068,6 @@
bad_swap_2:
swap_list_lock();
swap_map = p->swap_map;
- p->swap_device = NODEV;
p->swap_file = NULL;
p->swap_map = NULL;
p->flags = 0;
@@ -1090,7 +1093,7 @@
swap_list_lock();
for (i = 0; i < nr_swapfiles; i++) {
unsigned int j;
- if (swap_info[i].flags != SWP_USED)
+ if (!(swap_info[i].flags & SWP_USED))
continue;
for (j = 0; j < swap_info[i].max; ++j) {
switch (swap_info[i].swap_map[j]) {
-
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This archive was generated by hypermail 2b29 : Fri Feb 15 2002 - 21:00:24 EST