Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6ee412689027dc7954453aed392ab5c7599c0f73
Commit: 6ee412689027dc7954453aed392ab5c7599c0f73
Parent: aac00a8d0a53097063da532cbdf0b8775a4dcd53
Author: Trond Myklebust <[EMAIL PROTECTED]>
AuthorDate: Sun Jul 8 14:11:36 2007 -0400
Committer: Trond Myklebust <[EMAIL PROTECTED]>
CommitDate: Tue Jul 10 23:40:43 2007 -0400
NFSv4: Don't call OPEN if we already have an open stateid for a file
If we already have a stateid with the correct open mode for a given file,
then we can reuse that stateid instead of re-issuing an OPEN call without
violating the close-to-open caching semantics.
Signed-off-by: Trond Myklebust <[EMAIL PROTECTED]>
---
fs/nfs/nfs4proc.c | 49 +++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 41 insertions(+), 8 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index ea332e8..1de0766 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -324,6 +324,24 @@ static int nfs4_wait_for_completion_rpc_task(struct
rpc_task *task)
return ret;
}
+static int can_open_cached(struct nfs4_state *state, int mode)
+{
+ int ret = 0;
+ switch (mode & (FMODE_READ|FMODE_WRITE|O_EXCL)) {
+ case FMODE_READ:
+ ret |= test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0;
+ ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0;
+ break;
+ case FMODE_WRITE:
+ ret |= test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0;
+ ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0;
+ break;
+ case FMODE_READ|FMODE_WRITE:
+ ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0;
+ }
+ return ret;
+}
+
static int can_open_delegated(struct nfs_delegation *delegation, mode_t
open_flags)
{
if ((delegation->type & open_flags) != open_flags)
@@ -407,7 +425,7 @@ static void nfs4_return_incompatible_delegation(struct
inode *inode, mode_t open
nfs_inode_return_delegation(inode);
}
-static struct nfs4_state *nfs4_try_open_delegated(struct nfs4_opendata
*opendata)
+static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
{
struct nfs4_state *state = opendata->state;
struct nfs_inode *nfsi = NFS_I(state->inode);
@@ -418,9 +436,19 @@ static struct nfs4_state *nfs4_try_open_delegated(struct
nfs4_opendata *opendata
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
- if (delegation == NULL)
- goto out_unlock;
for (;;) {
+ if (can_open_cached(state, open_mode)) {
+ spin_lock(&state->owner->so_lock);
+ if (can_open_cached(state, open_mode)) {
+ update_open_stateflags(state, open_mode);
+ spin_unlock(&state->owner->so_lock);
+ rcu_read_unlock();
+ goto out_return_state;
+ }
+ spin_unlock(&state->owner->so_lock);
+ }
+ if (delegation == NULL)
+ break;
if (!can_open_delegated(delegation, open_mode))
break;
/* Save the delegation */
@@ -434,8 +462,9 @@ static struct nfs4_state *nfs4_try_open_delegated(struct
nfs4_opendata *opendata
ret = -EAGAIN;
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
+ /* If no delegation, try a cached open */
if (delegation == NULL)
- break;
+ continue;
/* Is the delegation still valid? */
if (memcmp(stateid.data, delegation->stateid.data,
sizeof(stateid.data)) != 0)
continue;
@@ -443,7 +472,6 @@ static struct nfs4_state *nfs4_try_open_delegated(struct
nfs4_opendata *opendata
update_open_stateid(state, NULL, &stateid, open_mode);
goto out_return_state;
}
-out_unlock:
rcu_read_unlock();
out:
return ERR_PTR(ret);
@@ -461,7 +489,7 @@ static struct nfs4_state
*nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data
int ret;
if (!data->rpc_done) {
- state = nfs4_try_open_delegated(data);
+ state = nfs4_try_open_cached(data);
goto out;
}
@@ -775,13 +803,14 @@ static void nfs4_open_prepare(struct rpc_task *task, void
*calldata)
if (data->state != NULL) {
struct nfs_delegation *delegation;
+ if (can_open_cached(data->state, data->o_arg.open_flags &
(FMODE_READ|FMODE_WRITE|O_EXCL)))
+ goto out_no_action;
rcu_read_lock();
delegation =
rcu_dereference(NFS_I(data->state->inode)->delegation);
if (delegation != NULL &&
(delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0) {
rcu_read_unlock();
- task->tk_action = NULL;
- return;
+ goto out_no_action;
}
rcu_read_unlock();
}
@@ -792,6 +821,10 @@ static void nfs4_open_prepare(struct rpc_task *task, void
*calldata)
msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR];
data->timestamp = jiffies;
rpc_call_setup(task, &msg, 0);
+ return;
+out_no_action:
+ task->tk_action = NULL;
+
}
static void nfs4_open_done(struct rpc_task *task, void *calldata)
-
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