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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 <trond.myklebust@primarydata.com>
hifive-unleashed-5.1
Trond Myklebust 2015-07-09 18:40:01 +02:00
parent df9cecc1a3
commit 7f27392cd4
2 changed files with 35 additions and 30 deletions
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2
fs/nfs/nfs4proc.c
View File

@ -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);

63
fs/nfs/pnfs.c
View File

@ -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)