| Message ID | 1349974296-48449-1-git-send-email-Trond.Myklebust@netapp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Oct 11, 2012 at 12:51 PM, Trond Myklebust <Trond.Myklebust@netapp.com> wrote: > There is nothing to prevent another thread from dereferencing ds->ds_clp > during or after the call to nfs4_ds_disconnect(), and Oopsing due to the > resulting NULL pointer. Yes. > > Instead, we should just rely on filelayout_mark_devid_invalid() to keep > us out of trouble by avoiding that deviceid. Why do we want to keep the connection and the nfs_client? For connection retry? -->Andy > > Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> > --- > fs/nfs/nfs4filelayout.c | 1 - > fs/nfs/nfs4filelayout.h | 1 - > fs/nfs/nfs4filelayoutdev.c | 22 ---------------------- > 3 files changed, 24 deletions(-) > > diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c > index 52d8472..816c2d0 100644 > --- a/fs/nfs/nfs4filelayout.c > +++ b/fs/nfs/nfs4filelayout.c > @@ -207,7 +207,6 @@ static int filelayout_async_handle_error(struct rpc_task *task, > clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags); > _pnfs_return_layout(inode); > rpc_wake_up(&tbl->slot_tbl_waitq); > - nfs4_ds_disconnect(clp); > /* fall through */ > default: > reset: > diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h > index dca47d78..8c07241 100644 > --- a/fs/nfs/nfs4filelayout.h > +++ b/fs/nfs/nfs4filelayout.h > @@ -149,6 +149,5 @@ extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr); > extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr); > struct nfs4_file_layout_dsaddr * > filelayout_get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags); > -void nfs4_ds_disconnect(struct nfs_client *clp); > > #endif /* FS_NFS_NFS4FILELAYOUT_H */ > diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c > index 3336d5e..a8eaa9b 100644 > --- a/fs/nfs/nfs4filelayoutdev.c > +++ b/fs/nfs/nfs4filelayoutdev.c > @@ -149,28 +149,6 @@ _data_server_lookup_locked(const struct list_head *dsaddrs) > } > > /* > - * Lookup DS by nfs_client pointer. Zero data server client pointer > - */ > -void nfs4_ds_disconnect(struct nfs_client *clp) > -{ > - struct nfs4_pnfs_ds *ds; > - struct nfs_client *found = NULL; > - > - dprintk("%s clp %p\n", __func__, clp); > - spin_lock(&nfs4_ds_cache_lock); > - list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) > - if (ds->ds_clp && ds->ds_clp == clp) { > - found = ds->ds_clp; > - ds->ds_clp = NULL; > - } > - spin_unlock(&nfs4_ds_cache_lock); > - if (found) { > - set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state); > - nfs_put_client(clp); > - } > -} > - > -/* > * Create an rpc connection to the nfs4_pnfs_ds data server > * Currently only supports IPv4 and IPv6 addresses > */ > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: Andy Adamson [mailto:androsadamson@gmail.com] > Sent: Thursday, October 11, 2012 1:51 PM > To: Myklebust, Trond > Cc: linux-nfs@vger.kernel.org > Subject: Re: [PATCH] NFSv4.1: Kill nfs4_ds_disconnect() > > On Thu, Oct 11, 2012 at 12:51 PM, Trond Myklebust > <Trond.Myklebust@netapp.com> wrote: > > There is nothing to prevent another thread from dereferencing > > ds->ds_clp during or after the call to nfs4_ds_disconnect(), and > > Oopsing due to the resulting NULL pointer. > > Yes. > > > > > Instead, we should just rely on filelayout_mark_devid_invalid() to > > keep us out of trouble by avoiding that deviceid. > > Why do we want to keep the connection and the nfs_client? For connection > retry? > The deviceid doesn't really want to keep the nfs_client, but I don't see how you can remove it safely in the current code. There is too much that relies on being able to dereference ds->ds_clp without any locking. As for the TCP connection: that is a property of the nfs_client and its RPC client, and as such should not be manipulated by pNFS. If there are other users, then they may be waiting for it to reconnect... -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c index 52d8472..816c2d0 100644 --- a/fs/nfs/nfs4filelayout.c +++ b/fs/nfs/nfs4filelayout.c @@ -207,7 +207,6 @@ static int filelayout_async_handle_error(struct rpc_task *task, clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags); _pnfs_return_layout(inode); rpc_wake_up(&tbl->slot_tbl_waitq); - nfs4_ds_disconnect(clp); /* fall through */ default: reset: diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h index dca47d78..8c07241 100644 --- a/fs/nfs/nfs4filelayout.h +++ b/fs/nfs/nfs4filelayout.h @@ -149,6 +149,5 @@ extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr); extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr); struct nfs4_file_layout_dsaddr * filelayout_get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags); -void nfs4_ds_disconnect(struct nfs_client *clp); #endif /* FS_NFS_NFS4FILELAYOUT_H */ diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c index 3336d5e..a8eaa9b 100644 --- a/fs/nfs/nfs4filelayoutdev.c +++ b/fs/nfs/nfs4filelayoutdev.c @@ -149,28 +149,6 @@ _data_server_lookup_locked(const struct list_head *dsaddrs) } /* - * Lookup DS by nfs_client pointer. Zero data server client pointer - */ -void nfs4_ds_disconnect(struct nfs_client *clp) -{ - struct nfs4_pnfs_ds *ds; - struct nfs_client *found = NULL; - - dprintk("%s clp %p\n", __func__, clp); - spin_lock(&nfs4_ds_cache_lock); - list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) - if (ds->ds_clp && ds->ds_clp == clp) { - found = ds->ds_clp; - ds->ds_clp = NULL; - } - spin_unlock(&nfs4_ds_cache_lock); - if (found) { - set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state); - nfs_put_client(clp); - } -} - -/* * Create an rpc connection to the nfs4_pnfs_ds data server * Currently only supports IPv4 and IPv6 addresses */
There is nothing to prevent another thread from dereferencing ds->ds_clp during or after the call to nfs4_ds_disconnect(), and Oopsing due to the resulting NULL pointer. Instead, we should just rely on filelayout_mark_devid_invalid() to keep us out of trouble by avoiding that deviceid. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> --- fs/nfs/nfs4filelayout.c | 1 - fs/nfs/nfs4filelayout.h | 1 - fs/nfs/nfs4filelayoutdev.c | 22 ---------------------- 3 files changed, 24 deletions(-)