Commit 01a05b33 authored by Al Viro's avatar Al Viro
Browse files

new helper: iterate_supers()



... and switch the simple "loop over superblocks and do something"
loops to it.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 35cf7ba0
......@@ -560,25 +560,17 @@ repeat:
return err;
}
static void do_thaw_all(struct work_struct *work)
static void do_thaw_one(struct super_block *sb, void *unused)
{
struct super_block *sb, *n;
char b[BDEVNAME_SIZE];
while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
printk(KERN_WARNING "Emergency Thaw on %s\n",
bdevname(sb->s_bdev, b));
}
spin_lock(&sb_lock);
list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
printk(KERN_WARNING "Emergency Thaw on %s\n",
bdevname(sb->s_bdev, b));
up_read(&sb->s_umount);
spin_lock(&sb_lock);
}
spin_unlock(&sb_lock);
static void do_thaw_all(struct work_struct *work)
{
iterate_supers(do_thaw_one, NULL);
kfree(work);
printk(KERN_WARNING "Emergency Thaw complete\n");
}
......
......@@ -8,12 +8,11 @@
#include <linux/writeback.h>
#include <linux/sysctl.h>
#include <linux/gfp.h>
#include "internal.h"
/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;
static void drop_pagecache_sb(struct super_block *sb)
static void drop_pagecache_sb(struct super_block *sb, void *unused)
{
struct inode *inode, *toput_inode = NULL;
......@@ -34,26 +33,6 @@ static void drop_pagecache_sb(struct super_block *sb)
iput(toput_inode);
}
static void drop_pagecache(void)
{
struct super_block *sb, *n;
spin_lock(&sb_lock);
list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
if (sb->s_root)
drop_pagecache_sb(sb);
up_read(&sb->s_umount);
spin_lock(&sb_lock);
__put_super(sb);
}
spin_unlock(&sb_lock);
}
static void drop_slab(void)
{
int nr_objects;
......@@ -69,7 +48,7 @@ int drop_caches_sysctl_handler(ctl_table *table, int write,
proc_dointvec_minmax(table, write, buffer, length, ppos);
if (write) {
if (sysctl_drop_caches & 1)
drop_pagecache();
iterate_supers(drop_pagecache_sb, NULL);
if (sysctl_drop_caches & 2)
drop_slab();
}
......
......@@ -18,7 +18,6 @@
#include <linux/quotaops.h>
#include <linux/types.h>
#include <linux/writeback.h>
#include "../internal.h"
static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
qid_t id)
......@@ -46,36 +45,22 @@ static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
return security_quotactl(cmd, type, id, sb);
}
static void quota_sync_one(struct super_block *sb, void *arg)
{
if (sb->s_qcop && sb->s_qcop->quota_sync)
sb->s_qcop->quota_sync(sb, *(int *)arg, 1);
}
static int quota_sync_all(int type)
{
struct super_block *sb, *n;
int ret;
if (type >= MAXQUOTAS)
return -EINVAL;
ret = security_quotactl(Q_SYNC, type, 0, NULL);
if (ret)
return ret;
spin_lock(&sb_lock);
list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
if (!sb->s_qcop || !sb->s_qcop->quota_sync)
continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
if (sb->s_root)
sb->s_qcop->quota_sync(sb, type, 1);
up_read(&sb->s_umount);
spin_lock(&sb_lock);
__put_super(sb);
}
spin_unlock(&sb_lock);
return 0;
if (!ret)
iterate_supers(quota_sync_one, &type);
return ret;
}
static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
......
......@@ -391,6 +391,36 @@ void sync_supers(void)
spin_unlock(&sb_lock);
}
/**
* iterate_supers - call function for all active superblocks
* @f: function to call
* @arg: argument to pass to it
*
* Scans the superblock list and calls given function, passing it
* locked superblock and given argument.
*/
void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
{
struct super_block *sb, *n;
spin_lock(&sb_lock);
list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
if (sb->s_root)
f(sb, arg);
up_read(&sb->s_umount);
spin_lock(&sb_lock);
__put_super(sb);
}
spin_unlock(&sb_lock);
}
/**
* get_super - get the superblock of a device
* @bdev: device to get the superblock for
......
......@@ -77,31 +77,18 @@ int sync_filesystem(struct super_block *sb)
}
EXPORT_SYMBOL_GPL(sync_filesystem);
static void sync_one_sb(struct super_block *sb, void *arg)
{
if (!(sb->s_flags & MS_RDONLY) && sb->s_bdi)
__sync_filesystem(sb, *(int *)arg);
}
/*
* Sync all the data for all the filesystems (called by sys_sync() and
* emergency sync)
*/
static void sync_filesystems(int wait)
{
struct super_block *sb, *n;
spin_lock(&sb_lock);
list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
sb->s_count++;
spin_unlock(&sb_lock);
down_read(&sb->s_umount);
if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi)
__sync_filesystem(sb, wait);
up_read(&sb->s_umount);
/* restart only when sb is no longer on the list */
spin_lock(&sb_lock);
__put_super(sb);
}
spin_unlock(&sb_lock);
iterate_supers(sync_one_sb, &wait);
}
/*
......
......@@ -2324,6 +2324,7 @@ extern struct super_block *get_super(struct block_device *);
extern struct super_block *get_active_super(struct block_device *bdev);
extern struct super_block *user_get_super(dev_t);
extern void drop_super(struct super_block *sb);
extern void iterate_supers(void (*)(struct super_block *, void *), void *);
extern int dcache_dir_open(struct inode *, struct file *);
extern int dcache_dir_close(struct inode *, struct file *);
......
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