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NFSv4.1: Don't cache deviceids that have no notifications

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The spec says that once all layouts that reference a given deviceid
have been returned, then we are only allowed to continue to cache
the deviceid if the metadata server supports notifications.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2015-03-09 14:48:32 -04:00
parent 4e59080397
commit df52699e4f
3 changed files with 13 additions and 0 deletions
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2
fs/nfs/nfs4proc.c
View file

@ -7962,6 +7962,8 @@ _nfs4_proc_getdeviceinfo(struct nfs_server *server,
status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
if (res.notification & ~args.notify_types)
dprintk("%s: unsupported notification\n", __func__);
if (res.notification != args.notify_types)
pdev->nocache = 1;
dprintk("<-- %s status=%d\n", __func__, status);

2
fs/nfs/pnfs.h
View file

@ -203,6 +203,7 @@ struct pnfs_device {
struct page **pages;
unsigned int pgbase;
unsigned int pglen; /* reply buffer length */
unsigned char nocache : 1;/* May not be cached */
};
#define NFS4_PNFS_GETDEVLIST_MAXNUM 16
@ -291,6 +292,7 @@ void pnfs_error_mark_layout_for_return(struct inode *inode,
enum {
NFS_DEVICEID_INVALID = 0, /* set when MDS clientid recalled */
NFS_DEVICEID_UNAVAILABLE, /* device temporarily unavailable */
NFS_DEVICEID_NOCACHE, /* device may not be cached */
};
/* pnfs_dev.c */

9
fs/nfs/pnfs_dev.c
View file

@ -149,6 +149,8 @@ nfs4_get_device_info(struct nfs_server *server,
*/
d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
gfp_flags);
if (d && pdev->nocache)
set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
out_free_pages:
for (i = 0; i < max_pages; i++)
@ -235,6 +237,7 @@ nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
return;
}
hlist_del_init_rcu(&d->node);
clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
spin_unlock(&nfs4_deviceid_lock);
/* balance the initial ref set in pnfs_insert_deviceid */
@ -269,6 +272,11 @@ EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
bool
nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
{
if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
if (atomic_add_unless(&d->ref, -1, 2))
return false;
nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
}
if (!atomic_dec_and_test(&d->ref))
return false;
d->ld->free_deviceid_node(d);
@ -312,6 +320,7 @@ _deviceid_purge_client(const struct nfs_client *clp, long hash)
if (d->nfs_client == clp && atomic_read(&d->ref)) {
hlist_del_init_rcu(&d->node);
hlist_add_head(&d->tmpnode, &tmp);
clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
}
rcu_read_unlock();
spin_unlock(&nfs4_deviceid_lock);