This prepares for future changes, where the layout state needs
to change atomically with several other variables. In particular,
it will need to know if lo->segs is empty. One possible future
alternative is to have a statelock that also covers lo->segs, but
this method is less intrusive. Moreover, the layoutstateid is not really
a read-mostly structure, as it is written on each LAYOUTGET.
Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxx>
---
fs/nfs/callback_proc.c | 8 +++---
fs/nfs/nfs4proc.c | 2 +
fs/nfs/nfs4xdr.c | 2 +
fs/nfs/pnfs.c | 57 +++++++++++++++--------------------------------
fs/nfs/pnfs.h | 6 ++--
5 files changed, 29 insertions(+), 46 deletions(-)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 84c5a1b..3e022a8 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -135,12 +135,11 @@ static bool
pnfs_is_next_layout_stateid(const struct pnfs_layout_hdr *lo,
const nfs4_stateid stateid)
{
- int seqlock;
bool res;
u32 oldseqid, newseqid;
- do {
- seqlock = read_seqbegin(&lo->seqlock);
+ spin_lock(&lo->inode->i_lock);
+ {
oldseqid = be32_to_cpu(lo->stateid.stateid.seqid);
newseqid = be32_to_cpu(stateid.stateid.seqid);
res = !memcmp(lo->stateid.stateid.other,
@@ -158,7 +157,8 @@ pnfs_is_next_layout_stateid(const struct pnfs_layout_hdr *lo,
if (res)
res = (newseqid == 1);
}
- } while (read_seqretry(&lo->seqlock, seqlock));
+ }
+ spin_unlock(&lo->inode->i_lock);
return res;
}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c854814..4705ea6 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5675,8 +5675,10 @@ static void nfs4_layoutreturn_release(void *calldata)
lrp->args.return_type, lo);
if (lrp->args.return_type == RETURN_FILE) {
+ spin_lock(&lo->inode->i_lock);
if (!lrp->res.lrs_present)
pnfs_invalidate_layout_stateid(lo);
+ spin_unlock(&lo->inode->i_lock);
pnfs_layoutreturn_release(lo, &lrp->args.range);
}
kfree(calldata);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index c178946..b146b48 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1904,7 +1904,9 @@ encode_layoutreturn(struct xdr_stream *xdr,
p = reserve_space(xdr, 16 + NFS4_STATEID_SIZE);
p = xdr_encode_hyper(p, args->range.offset);
p = xdr_encode_hyper(p, args->range.length);
+ spin_lock(&args->inode->i_lock);
pnfs_copy_layout_stateid(&stateid, NFS_I(args->inode)->layout);
+ spin_unlock(&args->inode->i_lock);
p = xdr_encode_opaque_fixed(p, &stateid.data,
NFS4_STATEID_SIZE);
p = reserve_space(xdr, 4);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c088cd4..7a6b24c 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -480,14 +480,14 @@ pnfs_destroy_all_layouts(struct nfs_client *clp)
*
* lo->stateid could be the open stateid, in which case we just use what given.
*/
-static void
+void
pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
const nfs4_stateid *new)
{
nfs4_stateid *old = &lo->stateid;
bool overwrite = false;
- write_seqlock(&lo->seqlock);
+ assert_spin_locked(&lo->inode->i_lock);
if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->state) ||
memcmp(old->stateid.other, new->stateid.other, sizeof(new->stateid.other)))
overwrite = true;
@@ -501,54 +501,34 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
}
if (overwrite)
memcpy(&old->stateid, &new->stateid, sizeof(new->stateid));
- write_sequnlock(&lo->seqlock);
-}
-
-static void
-pnfs_layout_from_open_stateid(struct pnfs_layout_hdr *lo,
- struct nfs4_state *state)
-{
- int seq;
-
- dprintk("--> %s\n", __func__);
- write_seqlock(&lo->seqlock);
- do {
- seq = read_seqbegin(&state->seqlock);
- memcpy(lo->stateid.data, state->stateid.data,
- sizeof(state->stateid.data));
- } while (read_seqretry(&state->seqlock, seq));
- set_bit(NFS_LAYOUT_STATEID_SET, &lo->state);
- write_sequnlock(&lo->seqlock);
- dprintk("<-- %s\n", __func__);
}
/* Layoutreturn may use an invalid stateid, just copy what is there */
void pnfs_copy_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo)
{
- int seq;
-
- do {
- seq = read_seqbegin(&lo->seqlock);
- memcpy(dst->data, lo->stateid.data, sizeof(lo->stateid.data));
- } while (read_seqretry(&lo->seqlock, seq));
+ assert_spin_locked(&lo->inode->i_lock);
+ memcpy(dst->data, lo->stateid.data, sizeof(lo->stateid.data));
}
void
pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state)
{
- int seq;
-
dprintk("--> %s\n", __func__);
- do {
- seq = read_seqbegin(&lo->seqlock);
- if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->state)) {
- /* This will trigger retry of the read */
- pnfs_layout_from_open_stateid(lo, open_state);
- } else
- memcpy(dst->data, lo->stateid.data,
- sizeof(lo->stateid.data));
- } while (read_seqretry(&lo->seqlock, seq));
+ spin_lock(&lo->inode->i_lock);
+ if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->state)) {
+ int seq;
+
+ do {
+ seq = read_seqbegin(&open_state->seqlock);
+ memcpy(dst->data, open_state->stateid.data,
+ sizeof(open_state->stateid.data));
+ } while (read_seqretry(&open_state->seqlock, seq));
+ set_bit(NFS_LAYOUT_STATEID_SET, &lo->state);
+ } else
+ memcpy(dst->data, lo->stateid.data,
+ sizeof(lo->stateid.data));
+ spin_unlock(&lo->inode->i_lock);
dprintk("<-- %s\n", __func__);
}
@@ -807,7 +787,6 @@ alloc_init_layout_hdr(struct inode *ino)
lo->refcount = 1;
INIT_LIST_HEAD(&lo->layouts);
INIT_LIST_HEAD(&lo->segs);
- seqlock_init(&lo->seqlock);
lo->inode = ino;
return lo;
}
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index c06b510..6e73fbe 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -96,7 +96,6 @@ struct pnfs_layout_hdr {
struct list_head layouts; /* other client layouts */
struct list_head segs; /* layout segments list */
int roc_iomode;/* return on close iomode, 0=none */
- seqlock_t seqlock; /* Protects the stateid */
nfs4_stateid stateid;
unsigned long state;
struct rpc_cred *cred; /* layoutcommit credential */
@@ -208,6 +207,8 @@ void pnfs_layoutreturn_release(struct pnfs_layout_hdr *,
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
void put_layout_hdr(struct inode *inode);
+void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
+ const nfs4_stateid *new);
void pnfs_copy_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo);
void pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state);
@@ -227,9 +228,8 @@ static inline int lo_fail_bit(u32 iomode)
static inline void pnfs_invalidate_layout_stateid(struct pnfs_layout_hdr *lo)
{
- write_seqlock(&lo->seqlock);
+ assert_spin_locked(&lo->inode->i_lock);
clear_bit(NFS_LAYOUT_STATEID_SET, &lo->state);
- write_sequnlock(&lo->seqlock);
}
static inline void get_lseg(struct pnfs_layout_segment *lseg)
--
1.7.2.1
--
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