cifs: implement recurring workqueue job to prune old tcons

Create a workqueue job that cleans out unused tlinks. For now, it uses
a hardcoded expire time of 10 minutes. When it's done, the work rearms
itself. On umount, the work is cancelled before tearing down the tlink
tree.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Jeff Layton 2010-10-06 19:51:12 -04:00 committed by Steve French
parent 3aa1c8c290
commit 2de970ff69
2 changed files with 58 additions and 1 deletions

View File

@ -59,5 +59,6 @@ struct cifs_sb_info {
char *mountdata; /* mount options received at mount time */
#endif
struct backing_dev_info bdi;
struct delayed_work prune_tlinks;
};
#endif /* _CIFS_FS_SB_H */

View File

@ -110,11 +110,13 @@ struct smb_vol {
struct nls_table *local_nls;
};
/* FIXME: should these be tunable? */
#define TLINK_ERROR_EXPIRE (1 * HZ)
#define TLINK_IDLE_EXPIRE (600 * HZ)
static int ipv4_connect(struct TCP_Server_Info *server);
static int ipv6_connect(struct TCP_Server_Info *server);
static void cifs_prune_tlinks(struct work_struct *work);
/*
* cifs tcp session reconnection
@ -2494,6 +2496,8 @@ convert_delimiter(char *path, char delim)
static void setup_cifs_sb(struct smb_vol *pvolume_info,
struct cifs_sb_info *cifs_sb)
{
INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
if (pvolume_info->rsize > CIFSMaxBufSize) {
cERROR(1, "rsize %d too large, using MaxBufSize",
pvolume_info->rsize);
@ -2899,6 +2903,9 @@ remote_path_check:
spin_unlock(&cifs_sb->tlink_tree_lock);
radix_tree_preload_end();
queue_delayed_work(system_nrt_wq, &cifs_sb->prune_tlinks,
TLINK_IDLE_EXPIRE);
mount_fail_check:
/* on error free sesinfo and tcon struct if needed */
if (rc) {
@ -3090,6 +3097,8 @@ cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb)
struct tcon_link *tlink[8];
unsigned long index = 0;
cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
do {
spin_lock(&cifs_sb->tlink_tree_lock);
ret = radix_tree_gang_lookup(&cifs_sb->tlink_tree,
@ -3363,3 +3372,50 @@ wait_for_construction:
return tlink;
}
/*
* periodic workqueue job that scans tcon_tree for a superblock and closes
* out tcons.
*/
static void
cifs_prune_tlinks(struct work_struct *work)
{
struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
prune_tlinks.work);
struct tcon_link *tlink[8];
unsigned long now = jiffies;
unsigned long index = 0;
int i, ret;
do {
spin_lock(&cifs_sb->tlink_tree_lock);
ret = radix_tree_gang_lookup(&cifs_sb->tlink_tree,
(void **)tlink, index,
ARRAY_SIZE(tlink));
/* increment index for next pass */
if (ret > 0)
index = tlink[ret - 1]->tl_index + 1;
for (i = 0; i < ret; i++) {
if (test_bit(TCON_LINK_MASTER, &tlink[i]->tl_flags) ||
atomic_read(&tlink[i]->tl_count) != 0 ||
time_after(tlink[i]->tl_time + TLINK_IDLE_EXPIRE,
now)) {
tlink[i] = NULL;
continue;
}
cifs_get_tlink(tlink[i]);
clear_bit(TCON_LINK_IN_TREE, &tlink[i]->tl_flags);
radix_tree_delete(&cifs_sb->tlink_tree,
tlink[i]->tl_index);
}
spin_unlock(&cifs_sb->tlink_tree_lock);
for (i = 0; i < ret; i++) {
if (tlink[i] != NULL)
cifs_put_tlink(tlink[i]);
}
} while (ret != 0);
queue_delayed_work(system_nrt_wq, &cifs_sb->prune_tlinks,
TLINK_IDLE_EXPIRE);
}