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. 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/nfs4xdr.c | 6 +++-
fs/nfs/pnfs.c | 50 ++++++++++++++++-------------------------------
fs/nfs/pnfs.h | 4 +--
4 files changed, 26 insertions(+), 42 deletions(-)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 4dabc62..74a6d6b 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -121,12 +121,11 @@ 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,
@@ -144,7 +143,8 @@ 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/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 238eeb2..550e457 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1915,8 +1915,10 @@ 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);
- pnfs_get_layout_stateid(&stateid, NFS_I(args->inode)->layout,
- NULL);
+ spin_lock(&args->inode->i_lock);
+ memcpy(stateid.data, NFS_I(args->inode)->layout->stateid.data,
+ NFS4_STATEID_SIZE);
+ 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 ec291d3..519055d 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -437,7 +437,7 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
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;
@@ -451,43 +451,27 @@ 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__);
}
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__);
}
@@ -761,7 +745,6 @@ 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;
}
@@ -1182,7 +1165,8 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
nfsi->layout->write_end_pos = 0;
nfsi->layout->cred = NULL;
__clear_bit(NFS_LAYOUT_NEED_LCOMMIT, &nfsi->layout->state);
- pnfs_get_layout_stateid(&data->args.stateid, nfsi->layout, NULL);
+ memcpy(data->args.stateid.data, nfsi->layout->stateid.data,
+ NFS4_STATEID_SIZE);
/* Reference for layoutcommit matched in pnfs_layoutcommit_release */
get_layout_hdr_locked(NFS_I(inode)->layout);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 7e06437..fdcfb9b 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 */
@@ -223,9 +222,8 @@ 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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