@@ -2386,18 +2386,103 @@ bool has_usable_swap(void)
return ret;
}
-SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
+static void release_swap_info_memory(struct swap_info_struct *p)
{
- struct swap_info_struct *p = NULL;
unsigned char *swap_map;
struct swap_cluster_info *cluster_info;
unsigned long *frontswap_map;
- struct file *swap_file, *victim;
+ struct file *swap_file;
struct address_space *mapping;
struct inode *inode;
+ unsigned int old_block_size;
+
+ mutex_lock(&swapon_mutex);
+ spin_lock(&swap_lock);
+ spin_lock(&p->lock);
+ drain_mmlist();
+
+ /* wait for anyone still in scan_swap_map */
+ p->highest_bit = 0; /* cuts scans short */
+ while (p->flags >= SWP_SCANNING) {
+ spin_unlock(&p->lock);
+ spin_unlock(&swap_lock);
+ schedule_timeout_uninterruptible(1);
+ spin_lock(&swap_lock);
+ spin_lock(&p->lock);
+ }
+
+ swap_file = p->swap_file;
+ mapping = p->swap_file->f_mapping;
+ old_block_size = p->old_block_size;
+ p->swap_file = NULL;
+ p->max = 0;
+ swap_map = p->swap_map;
+ p->swap_map = NULL;
+ cluster_info = p->cluster_info;
+ p->cluster_info = NULL;
+ frontswap_map = frontswap_map_get(p);
+ spin_unlock(&p->lock);
+ spin_unlock(&swap_lock);
+ arch_swap_invalidate_area(p->type);
+ frontswap_invalidate_area(p->type);
+ frontswap_map_set(p, NULL);
+ mutex_unlock(&swapon_mutex);
+ free_percpu(p->percpu_cluster);
+ p->percpu_cluster = NULL;
+ free_percpu(p->cluster_next_cpu);
+ p->cluster_next_cpu = NULL;
+ vfree(swap_map);
+ kvfree(cluster_info);
+ kvfree(frontswap_map);
+ /* Destroy swap account information */
+ swap_cgroup_swapoff(p->type);
+ exit_swap_address_space(p->type);
+
+ inode = mapping->host;
+ if (S_ISBLK(inode->i_mode)) {
+ struct block_device *bdev = I_BDEV(inode);
+
+ set_blocksize(bdev, old_block_size);
+ blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+ }
+
+ inode_lock(inode);
+ inode->i_flags &= ~S_SWAPFILE;
+ inode_unlock(inode);
+ filp_close(swap_file, NULL);
+}
+
+static void del_useless_swap_info(struct swap_info_struct *p)
+{
+ del_from_avail_list(p);
+ spin_lock(&p->lock);
+ if (p->prio < 0) {
+ struct swap_info_struct *si = p;
+ int nid;
+
+ plist_for_each_entry_continue(si, &swap_active_head, list) {
+ si->prio++;
+ si->list.prio--;
+ for_each_node(nid) {
+ if (si->avail_lists[nid].prio != 1)
+ si->avail_lists[nid].prio--;
+ }
+ }
+ least_priority++;
+ }
+ plist_del(&p->list, &swap_active_head);
+ atomic_long_sub(p->pages, &nr_swap_pages);
+ p->flags &= ~SWP_WRITEOK;
+ spin_unlock(&p->lock);
+}
+
+SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
+{
+ struct swap_info_struct *p = NULL;
+ struct file *victim;
+ struct address_space *mapping;
struct filename *pathname;
int err, found = 0;
- unsigned int old_block_size;
unsigned int inuse_pages;
if (!capable(CAP_SYS_ADMIN))
@@ -2440,26 +2525,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
spin_unlock(&swap_lock);
goto out_dput;
}
- del_from_avail_list(p);
- spin_lock(&p->lock);
- if (p->prio < 0) {
- struct swap_info_struct *si = p;
- int nid;
- plist_for_each_entry_continue(si, &swap_active_head, list) {
- si->prio++;
- si->list.prio--;
- for_each_node(nid) {
- if (si->avail_lists[nid].prio != 1)
- si->avail_lists[nid].prio--;
- }
- }
- least_priority++;
- }
- plist_del(&p->list, &swap_active_head);
- atomic_long_sub(p->pages, &nr_swap_pages);
- p->flags &= ~SWP_WRITEOK;
- spin_unlock(&p->lock);
+ del_useless_swap_info(p);
spin_unlock(&swap_lock);
disable_swap_slots_cache_lock();
@@ -2497,60 +2564,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
if (!p->bdev || !bdev_nonrot(p->bdev))
atomic_dec(&nr_rotate_swap);
- mutex_lock(&swapon_mutex);
- spin_lock(&swap_lock);
- spin_lock(&p->lock);
- drain_mmlist();
-
- /* wait for anyone still in scan_swap_map_slots */
- p->highest_bit = 0; /* cuts scans short */
- while (p->flags >= SWP_SCANNING) {
- spin_unlock(&p->lock);
- spin_unlock(&swap_lock);
- schedule_timeout_uninterruptible(1);
- spin_lock(&swap_lock);
- spin_lock(&p->lock);
- }
-
- swap_file = p->swap_file;
- old_block_size = p->old_block_size;
- p->swap_file = NULL;
- p->max = 0;
- swap_map = p->swap_map;
- p->swap_map = NULL;
- cluster_info = p->cluster_info;
- p->cluster_info = NULL;
- frontswap_map = frontswap_map_get(p);
- spin_unlock(&p->lock);
- spin_unlock(&swap_lock);
- arch_swap_invalidate_area(p->type);
- frontswap_invalidate_area(p->type);
- frontswap_map_set(p, NULL);
- mutex_unlock(&swapon_mutex);
- free_percpu(p->percpu_cluster);
- p->percpu_cluster = NULL;
- free_percpu(p->cluster_next_cpu);
- p->cluster_next_cpu = NULL;
- vfree(swap_map);
- kvfree(cluster_info);
- kvfree(frontswap_map);
- /* Destroy swap account information */
- swap_cgroup_swapoff(p->type);
- exit_swap_address_space(p->type);
-
- inode = mapping->host;
- if (S_ISBLK(inode->i_mode)) {
- struct block_device *bdev = I_BDEV(inode);
-
- set_blocksize(bdev, old_block_size);
- blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
- }
-
- inode_lock(inode);
- inode->i_flags &= ~S_SWAPFILE;
- inode_unlock(inode);
- filp_close(swap_file, NULL);
-
+ release_swap_info_memory(p);
/*
* Clear the SWP_USED flag after all resources are freed so that swapon
* can reuse this swap_info in alloc_swap_info() safely. It is ok to
In order to realize the interface reuse in the swapoff resource release process, some of the operations are abstracted into separate interfaces. Only code movement, no functional modifications and changes. del_useless_swap_info(): Remove specific swap_info_struct from swap_active_head and update total_swap_pages. release_swap_info_memory(): Clear the corresponding resources of swap_info_struct. Signed-off-by: liubo <liubo254@huawei.com> --- v2: Only code movement, no functional modifications and changes. Former: https://lore.kernel.org/linux-mm/20220528084941.28391-1-liubo254@huawei.com/ --- mm/swapfile.c | 168 +++++++++++++++++++++++++++----------------------- 1 file changed, 91 insertions(+), 77 deletions(-)