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NFSv4.1/pnfs: Fix a close/delegreturn hang when return-on-close is set

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The helper pnfs_roc() has already verified that we have no delegations,
and no further open files, hence no outstanding I/O and it has marked
all the return-on-close lsegs as being invalid.
Furthermore, it sets the NFS_LAYOUT_RETURN bit, thus serialising the
close/delegreturn with all future layoutget calls on this inode.

The checks in pnfs_roc_drain() for valid layout segments are therefore
redundant: those cannot exist until another layoutget completes.
The other check for whether or not NFS_LAYOUT_RETURN is set, actually
causes a hang, since we already know that we hold that flag.

To fix, we therefore strip out all the functionality in pnfs_roc_drain()
except the retrieval of the barrier state, and then rename the function
accordingly.

Reported-by: Christoph Hellwig <hch@infradead.org>
Fixes: 5c4a79fb2b ("Don't prevent layoutgets when doing return-on-close")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2015-08-18 23:23:21 -05:00
parent 7e94d6c4ab
commit 4ff376feaf
3 changed files with 8 additions and 35 deletions
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12
fs/nfs/nfs4proc.c
View file

@ -2737,11 +2737,8 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data)
if (calldata->arg.fmode == 0) {
task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE];
if (calldata->roc &&
pnfs_roc_drain(inode, &calldata->roc_barrier, task)) {
nfs_release_seqid(calldata->arg.seqid);
goto out_wait;
}
if (calldata->roc)
pnfs_roc_get_barrier(inode, &calldata->roc_barrier);
}
calldata->arg.share_access =
nfs4_map_atomic_open_share(NFS_SERVER(inode),
@ -5289,9 +5286,8 @@ static void nfs4_delegreturn_prepare(struct rpc_task *task, void *data)
d_data = (struct nfs4_delegreturndata *)data;
if (d_data->roc &&
pnfs_roc_drain(d_data->inode, &d_data->roc_barrier, task))
return;
if (d_data->roc)
pnfs_roc_get_barrier(d_data->inode, &d_data->roc_barrier);
nfs4_setup_sequence(d_data->res.server,
&d_data->args.seq_args,

24
fs/nfs/pnfs.c
View file

@ -1141,25 +1141,14 @@ void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
spin_unlock(&ino->i_lock);
}
bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg;
nfs4_stateid stateid;
u32 current_seqid;
bool layoutreturn = false;
spin_lock(&ino->i_lock);
list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list) {
if (!test_bit(NFS_LSEG_ROC, &lseg->pls_flags))
continue;
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
continue;
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
spin_unlock(&ino->i_lock);
return true;
}
lo = nfsi->layout;
current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
@ -1168,18 +1157,7 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
*/
*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
stateid = lo->plh_stateid;
if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
&lo->plh_flags))
layoutreturn = pnfs_prepare_layoutreturn(lo);
if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
spin_unlock(&ino->i_lock);
if (layoutreturn) {
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false);
return true;
}
return false;
}
/*

7
fs/nfs/pnfs.h
View file

@ -267,7 +267,7 @@ int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
bool pnfs_roc(struct inode *ino);
void pnfs_roc_release(struct inode *ino);
void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task);
void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier);
void pnfs_set_layoutcommit(struct inode *, struct pnfs_layout_segment *, loff_t);
void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data);
int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
@ -605,10 +605,9 @@ pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
{
}
static inline bool
pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
static inline void
pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
{
return false;
}
static inline void set_pnfs_layoutdriver(struct nfs_server *s,