From a073dbff359f4741013ae4b8395f5364c5e00b48 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 20 Mar 2013 12:34:32 -0400 Subject: NFSv4.1: Fix a race in pNFS layoutcommit We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations where the two are out of sync. The first half of the problem is to ensure that pnfs_layoutcommit_inode clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg. We still need to keep the reference to those segments until the RPC call is finished, so in order to make it clear _where_ those references come from, we add a helper pnfs_list_write_lseg_done() that cleans up after pnfs_list_write_lseg. Signed-off-by: Trond Myklebust Acked-by: Benny Halevy Cc: stable@vger.kernel.org --- fs/nfs/nfs4proc.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'fs/nfs/nfs4proc.c') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index b2671cb0f901..6ccdd4fd9b59 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6416,22 +6416,8 @@ nfs4_layoutcommit_done(struct rpc_task *task, void *calldata) static void nfs4_layoutcommit_release(void *calldata) { struct nfs4_layoutcommit_data *data = calldata; - struct pnfs_layout_segment *lseg, *tmp; - unsigned long *bitlock = &NFS_I(data->args.inode)->flags; pnfs_cleanup_layoutcommit(data); - /* Matched by references in pnfs_set_layoutcommit */ - list_for_each_entry_safe(lseg, tmp, &data->lseg_list, pls_lc_list) { - list_del_init(&lseg->pls_lc_list); - if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, - &lseg->pls_flags)) - pnfs_put_lseg(lseg); - } - - clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock); - smp_mb__after_clear_bit(); - wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING); - put_rpccred(data->cred); kfree(data); } -- cgit v1.2.3 From 240286725d854331422cb15957f8d9bf2741d4e3 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 20 Mar 2013 13:23:33 -0400 Subject: NFSv4.1: Add a helper pnfs_commit_and_return_layout In order to be able to safely return the layout in nfs4_proc_setattr, we need to block new uses of the layout, wait for all outstanding users of the layout to complete, commit the layout and then return it. This patch adds a helper in order to do all this safely. Signed-off-by: Trond Myklebust Cc: Boaz Harrosh --- fs/nfs/nfs4proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/nfs4proc.c') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 6ccdd4fd9b59..26431cf62ddb 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2632,7 +2632,7 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr, int status; if (pnfs_ld_layoutret_on_setattr(inode)) - pnfs_return_layout(inode); + pnfs_commit_and_return_layout(inode); nfs_fattr_init(fattr); -- cgit v1.2.3