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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-01-25 00:14:34 +0100 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-01-30 08:06:12 +0100 |
commit | e6f810759505bc86c009854b82cc495ffd8eb020 (patch) | |
tree | 1590631fe3b222d49015dd53b421a5547e13e4dc /fs/nfs/delegation.c | |
parent | nfs: convert NFS_*(inode) helpers to static inline (diff) | |
download | linux-e6f810759505bc86c009854b82cc495ffd8eb020.tar.xz linux-e6f810759505bc86c009854b82cc495ffd8eb020.zip |
NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/delegation.c')
-rw-r--r-- | fs/nfs/delegation.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index b03dcd8403f1..2dead8d1dd55 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -174,11 +174,11 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct return status; } -static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation) +static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) { int res = 0; - res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid); + res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync); nfs_free_delegation(delegation); return res; } @@ -208,7 +208,7 @@ static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegat up_read(&clp->cl_sem); nfs_msync_inode(inode); - return nfs_do_return_delegation(inode, delegation); + return nfs_do_return_delegation(inode, delegation, 1); } static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid) @@ -228,6 +228,27 @@ nomatch: return NULL; } +/* + * This function returns the delegation without reclaiming opens + * or protecting against delegation reclaims. + * It is therefore really only safe to be called from + * nfs4_clear_inode() + */ +void nfs_inode_return_delegation_noreclaim(struct inode *inode) +{ + struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_delegation *delegation; + + if (rcu_dereference(nfsi->delegation) != NULL) { + spin_lock(&clp->cl_lock); + delegation = nfs_detach_delegation_locked(nfsi, NULL); + spin_unlock(&clp->cl_lock); + if (delegation != NULL) + nfs_do_return_delegation(inode, delegation, 0); + } +} + int nfs_inode_return_delegation(struct inode *inode) { struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; @@ -388,7 +409,7 @@ static int recall_thread(void *data) nfs_msync_inode(inode); if (delegation != NULL) - nfs_do_return_delegation(inode, delegation); + nfs_do_return_delegation(inode, delegation, 1); iput(inode); module_put_and_exit(0); } |