Commit 531d56ec authored by Jeff Garzik's avatar Jeff Garzik

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"
parent 0a67f33c
......@@ -50,8 +50,12 @@ union swap_header {
#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 @@ union swap_header {
*/
struct swap_info_struct {
unsigned int flags;
kdev_t swap_device;
spinlock_t sdev_lock;
struct file *swap_file;
unsigned short * swap_map;
......
......@@ -114,7 +114,7 @@ swp_entry_t get_swap_page(void)
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 @@ asmlinkage long sys_swapoff(const char * specialfile)
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 @@ asmlinkage long sys_swapoff(const char * specialfile)
}
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 @@ asmlinkage long sys_swapoff(const char * specialfile)
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 @@ asmlinkage long sys_swapoff(const char * specialfile)
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 @@ int get_swaparea_info(char *buf)
}
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 is_swap_partition(kdev_t dev) {
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 @@ asmlinkage long sys_swapon(const char * specialfile, int swap_flags)
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 @@ asmlinkage long sys_swapon(const char * specialfile, int swap_flags)
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 @@ asmlinkage long sys_swapon(const char * specialfile, int swap_flags)
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 @@ asmlinkage long sys_swapon(const char * specialfile, int swap_flags)
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 @@ void si_swapinfo(struct sysinfo *val)
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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