From ea7c38fef0b774a5dc16fb0ca5935f0ae8568176 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 5 Feb 2015 15:13:24 -0500 Subject: [PATCH] NFSv4: Ensure we reference the inode for return-on-close in delegreturn If we have to do a return-on-close in the delegreturn code, then we must ensure that the inode and super block remain referenced. Cc: Peng Tao Cc: stable@vger.kernel.org # 3.17.x Signed-off-by: Trond Myklebust Reviewed-by: Peng Tao --- fs/nfs/internal.h | 22 +++++++++++++++++++++- fs/nfs/nfs4proc.c | 14 +++++++++----- fs/nfs/super.c | 9 ++++++--- 3 files changed, 36 insertions(+), 9 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index a98cf2006179..21469e6e3834 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -391,7 +391,7 @@ extern struct rpc_stat nfs_rpcstat; extern int __init register_nfs_fs(void); extern void __exit unregister_nfs_fs(void); -extern void nfs_sb_active(struct super_block *sb); +extern bool nfs_sb_active(struct super_block *sb); extern void nfs_sb_deactive(struct super_block *sb); /* namespace.c */ @@ -514,6 +514,26 @@ extern int nfs41_walk_client_list(struct nfs_client *clp, struct nfs_client **result, struct rpc_cred *cred); +static inline struct inode *nfs_igrab_and_active(struct inode *inode) +{ + inode = igrab(inode); + if (inode != NULL && !nfs_sb_active(inode->i_sb)) { + iput(inode); + inode = NULL; + } + return inode; +} + +static inline void nfs_iput_and_deactive(struct inode *inode) +{ + if (inode != NULL) { + struct super_block *sb = inode->i_sb; + + iput(inode); + nfs_sb_deactive(sb); + } +} + /* * Determine the device name as a string */ diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index cd4295d84d54..dd892a4e7eb3 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5175,9 +5175,13 @@ static void nfs4_delegreturn_done(struct rpc_task *task, void *calldata) static void nfs4_delegreturn_release(void *calldata) { struct nfs4_delegreturndata *data = calldata; + struct inode *inode = data->inode; - if (data->roc) - pnfs_roc_release(data->inode); + if (inode) { + if (data->roc) + pnfs_roc_release(inode); + nfs_iput_and_deactive(inode); + } kfree(calldata); } @@ -5234,9 +5238,9 @@ static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, co nfs_fattr_init(data->res.fattr); data->timestamp = jiffies; data->rpc_status = 0; - data->inode = inode; - data->roc = list_empty(&NFS_I(inode)->open_files) ? - pnfs_roc(inode) : false; + data->inode = nfs_igrab_and_active(inode); + if (data->inode) + data->roc = nfs4_roc(inode); task_setup_data.callback_data = data; msg.rpc_argp = &data->args; diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 31a11b0e885d..368d9395d2e7 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -405,12 +405,15 @@ void __exit unregister_nfs_fs(void) unregister_filesystem(&nfs_fs_type); } -void nfs_sb_active(struct super_block *sb) +bool nfs_sb_active(struct super_block *sb) { struct nfs_server *server = NFS_SB(sb); - if (atomic_inc_return(&server->active) == 1) - atomic_inc(&sb->s_active); + if (!atomic_inc_not_zero(&sb->s_active)) + return false; + if (atomic_inc_return(&server->active) != 1) + atomic_dec(&sb->s_active); + return true; } EXPORT_SYMBOL_GPL(nfs_sb_active);