2015-07-13 05:20:31

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 1/5] pNFS: Layoutreturn must invalidate all existing layout segments.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4proc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 9f24238032f8..671498ca36d7 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7964,16 +7964,19 @@ static void nfs4_layoutreturn_release(void *calldata)
{
struct nfs4_layoutreturn *lrp = calldata;
struct pnfs_layout_hdr *lo = lrp->args.layout;
+ LIST_HEAD(freeme);

dprintk("--> %s\n", __func__);
spin_lock(&lo->plh_inode->i_lock);
if (lrp->res.lrs_present)
pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
+ pnfs_mark_matching_lsegs_invalid(lo, &freeme, &lrp->args.range);
pnfs_clear_layoutreturn_waitbit(lo);
clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &lo->plh_flags);
rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
lo->plh_block_lgets--;
spin_unlock(&lo->plh_inode->i_lock);
+ pnfs_free_lseg_list(&freeme);
pnfs_put_layout_hdr(lrp->args.layout);
nfs_iput_and_deactive(lrp->inode);
kfree(calldata);
--
2.4.3



2015-07-13 05:20:33

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 2/5] pNFS: pnfs_roc_drain should return 'true' when sleeping

Also clean up the case where we don't find a return-on-close layout segment.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pnfs.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0ba9a02c9566..8e9f467e409c 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1146,14 +1146,14 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
struct pnfs_layout_segment *lseg;
nfs4_stateid stateid;
u32 current_seqid;
- bool found = false, layoutreturn = false;
+ 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)) {
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
- found = true;
- goto out;
+ spin_unlock(&ino->i_lock);
+ return true;
}
lo = nfsi->layout;
current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
@@ -1162,23 +1162,21 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
* a barrier, we choose the worst-case barrier.
*/
*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
-out:
- if (!found) {
- stateid = lo->plh_stateid;
- layoutreturn =
- test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
+ stateid = lo->plh_stateid;
+ layoutreturn = test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
&lo->plh_flags);
- if (layoutreturn) {
- lo->plh_block_lgets++;
- pnfs_get_layout_hdr(lo);
- }
+ if (layoutreturn) {
+ lo->plh_block_lgets++;
+ pnfs_get_layout_hdr(lo);
}
+
spin_unlock(&ino->i_lock);
if (layoutreturn) {
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false);
+ return true;
}
- return found;
+ return false;
}

/*
--
2.4.3


2015-07-13 05:20:35

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 3/5] pNFS: Fix races between return-on-close and layoutreturn.

If one or more of the layout segments reports an error during I/O, then
we may have to send a layoutreturn to report the error back to the NFS
metadata server.
This patch ensures that the return-on-close code can detect the
outstanding layoutreturn, and not preempt it.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/nfs4proc.c | 2 --
fs/nfs/pnfs.c | 63 ++++++++++++++++++++++++++++++-------------------------
2 files changed, 35 insertions(+), 30 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 671498ca36d7..c5c9e0d070f8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7972,8 +7972,6 @@ static void nfs4_layoutreturn_release(void *calldata)
pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
pnfs_mark_matching_lsegs_invalid(lo, &freeme, &lrp->args.range);
pnfs_clear_layoutreturn_waitbit(lo);
- clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &lo->plh_flags);
- rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
lo->plh_block_lgets--;
spin_unlock(&lo->plh_inode->i_lock);
pnfs_free_lseg_list(&freeme);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 8e9f467e409c..27e2bcaa88da 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -352,7 +352,7 @@ pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
{
struct pnfs_layout_segment *s;

- if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+ if (!test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
return false;

list_for_each_entry(s, &lo->plh_segs, pls_list)
@@ -362,6 +362,18 @@ pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
return true;
}

+static bool
+pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo)
+{
+ if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
+ return false;
+ lo->plh_return_iomode = 0;
+ lo->plh_block_lgets++;
+ pnfs_get_layout_hdr(lo);
+ clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &lo->plh_flags);
+ return true;
+}
+
static void pnfs_layoutreturn_before_put_lseg(struct pnfs_layout_segment *lseg,
struct pnfs_layout_hdr *lo, struct inode *inode)
{
@@ -372,17 +384,16 @@ static void pnfs_layoutreturn_before_put_lseg(struct pnfs_layout_segment *lseg,
if (pnfs_layout_need_return(lo, lseg)) {
nfs4_stateid stateid;
enum pnfs_iomode iomode;
+ bool send;

stateid = lo->plh_stateid;
iomode = lo->plh_return_iomode;
- /* decreased in pnfs_send_layoutreturn() */
- lo->plh_block_lgets++;
- lo->plh_return_iomode = 0;
+ send = pnfs_prepare_layoutreturn(lo);
spin_unlock(&inode->i_lock);
- pnfs_get_layout_hdr(lo);
-
- /* Send an async layoutreturn so we dont deadlock */
- pnfs_send_layoutreturn(lo, stateid, iomode, false);
+ if (send) {
+ /* Send an async layoutreturn so we dont deadlock */
+ pnfs_send_layoutreturn(lo, stateid, iomode, false);
+ }
} else
spin_unlock(&inode->i_lock);
}
@@ -924,6 +935,7 @@ void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
smp_mb__after_atomic();
wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
+ rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
}

static int
@@ -978,6 +990,7 @@ _pnfs_return_layout(struct inode *ino)
LIST_HEAD(tmp_list);
nfs4_stateid stateid;
int status = 0, empty;
+ bool send;

dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);

@@ -1007,17 +1020,18 @@ _pnfs_return_layout(struct inode *ino)
/* Don't send a LAYOUTRETURN if list was initially empty */
if (empty) {
spin_unlock(&ino->i_lock);
- pnfs_put_layout_hdr(lo);
dprintk("NFS: %s no layout segments to return\n", __func__);
- goto out;
+ goto out_put_layout_hdr;
}

set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
- lo->plh_block_lgets++;
+ send = pnfs_prepare_layoutreturn(lo);
spin_unlock(&ino->i_lock);
pnfs_free_lseg_list(&tmp_list);
-
- status = pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
+ if (send)
+ status = pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
+out_put_layout_hdr:
+ pnfs_put_layout_hdr(lo);
out:
dprintk("<-- %s status: %d\n", __func__, status);
return status;
@@ -1097,13 +1111,9 @@ bool pnfs_roc(struct inode *ino)
out_noroc:
if (lo) {
stateid = lo->plh_stateid;
- layoutreturn =
- test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
- &lo->plh_flags);
- if (layoutreturn) {
- lo->plh_block_lgets++;
- pnfs_get_layout_hdr(lo);
- }
+ if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
+ &lo->plh_flags))
+ layoutreturn = pnfs_prepare_layoutreturn(lo);
}
spin_unlock(&ino->i_lock);
if (layoutreturn) {
@@ -1163,16 +1173,14 @@ 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;
- layoutreturn = test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
- &lo->plh_flags);
- if (layoutreturn) {
- lo->plh_block_lgets++;
- pnfs_get_layout_hdr(lo);
- }
+ 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) {
- rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false);
return true;
}
@@ -1693,7 +1701,6 @@ void pnfs_error_mark_layout_for_return(struct inode *inode,
spin_lock(&inode->i_lock);
/* set failure bit so that pnfs path will be retried later */
pnfs_layout_set_fail_bit(lo, iomode);
- set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
if (lo->plh_return_iomode == 0)
lo->plh_return_iomode = range.iomode;
else if (lo->plh_return_iomode != range.iomode)
--
2.4.3


2015-07-13 05:20:36

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 4/5] pNFS: pnfs_roc_drain() fix a race with open

If a process reopens the file before we can send off the CLOSE/DELEGRETURN,
then pnfs_roc_drain() may end up waiting for a new set of layout segments
that are marked as return-on-close, but haven't yet been returned.

Fix this by only waiting for those layout segments that were invalidated in
pnfs_roc().

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pnfs.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 27e2bcaa88da..b02e32e2abeb 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1159,12 +1159,15 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
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)) {
- rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
- spin_unlock(&ino->i_lock);
- return true;
- }
+ 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);

--
2.4.3


2015-07-13 05:20:38

by Trond Myklebust

[permalink] [raw]
Subject: [PATCH 5/5] pNFS: Don't throw out valid layout segments

It is OK for layout segments to remain hashed even if no-one holds any
references to them, provided that the segments are still valid.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/pnfs.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b02e32e2abeb..18aa3b7962eb 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -422,6 +422,10 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
pnfs_layoutreturn_before_put_lseg(lseg, lo, inode);

if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
+ if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
+ spin_unlock(&inode->i_lock);
+ return;
+ }
pnfs_get_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
spin_unlock(&inode->i_lock);
@@ -462,6 +466,8 @@ pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
if (atomic_dec_and_test(&lseg->pls_refcount)) {
struct pnfs_layout_hdr *lo = lseg->pls_layout;
+ if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
+ return;
pnfs_get_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
pnfs_free_lseg_async(lseg);
--
2.4.3