NFSv4.1: Optimise layout return-on-close

Optimise the layout return on close code by ensuring that

1) Add a check for whether we hold a layout before taking any spinlocks
2) Only take the spin lock once
3) Use nfs_state->state to speed up open file checks

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2015-01-24 13:54:37 -05:00
parent b4019c0e21
commit 40dd4b7aee
3 changed files with 31 additions and 40 deletions

View File

@ -2714,45 +2714,10 @@ static const struct rpc_call_ops nfs4_close_ops = {
.rpc_release = nfs4_free_closedata,
};
static bool nfs4_state_has_opener(struct nfs4_state *state)
{
/* first check existing openers */
if (test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0 &&
state->n_rdonly != 0)
return true;
if (test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0 &&
state->n_wronly != 0)
return true;
if (test_bit(NFS_O_RDWR_STATE, &state->flags) != 0 &&
state->n_rdwr != 0)
return true;
return false;
}
static bool nfs4_roc(struct inode *inode)
{
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_open_context *ctx;
struct nfs4_state *state;
spin_lock(&inode->i_lock);
list_for_each_entry(ctx, &nfsi->open_files, list) {
state = ctx->state;
if (state == NULL)
continue;
if (nfs4_state_has_opener(state)) {
spin_unlock(&inode->i_lock);
return false;
}
}
spin_unlock(&inode->i_lock);
if (nfs4_check_delegation(inode, FMODE_READ))
if (!nfs_have_layout(inode))
return false;
return pnfs_roc(inode);
}

View File

@ -34,6 +34,7 @@
#include "pnfs.h"
#include "iostat.h"
#include "nfs4trace.h"
#include "delegation.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
@ -954,30 +955,45 @@ pnfs_commit_and_return_layout(struct inode *inode)
bool pnfs_roc(struct inode *ino)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct nfs_open_context *ctx;
struct nfs4_state *state;
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg, *tmp;
LIST_HEAD(tmp_list);
bool found = false;
spin_lock(&ino->i_lock);
lo = NFS_I(ino)->layout;
lo = nfsi->layout;
if (!lo || !test_and_clear_bit(NFS_LAYOUT_ROC, &lo->plh_flags) ||
test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
goto out_nolayout;
goto out_noroc;
/* Don't return layout if we hold a delegation */
if (nfs4_check_delegation(ino, FMODE_READ))
goto out_noroc;
list_for_each_entry(ctx, &nfsi->open_files, list) {
state = ctx->state;
/* Don't return layout if there is open file state */
if (state != NULL && state->state != 0)
goto out_noroc;
}
list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
mark_lseg_invalid(lseg, &tmp_list);
found = true;
}
if (!found)
goto out_nolayout;
goto out_noroc;
lo->plh_block_lgets++;
pnfs_get_layout_hdr(lo); /* matched in pnfs_roc_release */
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&tmp_list);
return true;
out_nolayout:
out_noroc:
spin_unlock(&ino->i_lock);
return false;
}

View File

@ -275,6 +275,11 @@ void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
void nfs4_deviceid_purge_client(const struct nfs_client *);
static inline bool nfs_have_layout(struct inode *inode)
{
return NFS_I(inode)->layout != NULL;
}
static inline struct nfs4_deviceid_node *
nfs4_get_deviceid(struct nfs4_deviceid_node *d)
{
@ -427,6 +432,11 @@ static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
#endif /* NFS_DEBUG */
#else /* CONFIG_NFS_V4_1 */
static inline bool nfs_have_layout(struct inode *inode)
{
return false;
}
static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
{
}