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nfs/flexfiles: send layoutreturn before freeing lseg 

Otherwise we'll lose error tracking information when
encoding layoutreturn.

pnfs_put_lseg may be called from rpc callbacks. So we should not
call pnfs_send_layoutreturn directly because it can deadlock in
the rpc layer.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <loghyr@primarydata.com>
This commit is contained in:
Peng Tao 2014-10-20 14:44:38 +08:00 committed by Tom Haynes
parent 193e3aa2cc
commit 27b6f53987
1 changed files with 56 additions and 25 deletions
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81
fs/nfs/pnfs.c
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@ -346,8 +346,7 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
/* Return true if layoutreturn is needed */
static bool
pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
struct pnfs_layout_segment *lseg,
nfs4_stateid *stateid, enum pnfs_iomode *iomode)
struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_segment *s;
@ -355,17 +354,54 @@ pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
return false;
list_for_each_entry(s, &lo->plh_segs, pls_list)
if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
if (s != lseg && test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
return false;
*stateid = lo->plh_stateid;
*iomode = lo->plh_return_iomode;
/* decreased in pnfs_send_layoutreturn() */
lo->plh_block_lgets++;
lo->plh_return_iomode = 0;
return true;
}
static void pnfs_layoutreturn_free_lseg(struct work_struct *work)
{
struct pnfs_layout_segment *lseg;
struct pnfs_layout_hdr *lo;
struct inode *inode;
lseg = container_of(work, struct pnfs_layout_segment, pls_work);
WARN_ON(atomic_read(&lseg->pls_refcount));
lo = lseg->pls_layout;
inode = lo->plh_inode;
spin_lock(&inode->i_lock);
if (pnfs_layout_need_return(lo, lseg)) {
nfs4_stateid stateid;
enum pnfs_iomode iomode;
stateid = lo->plh_stateid;
iomode = lo->plh_return_iomode;
/* decreased in pnfs_send_layoutreturn() */
lo->plh_block_lgets++;
lo->plh_return_iomode = 0;
spin_unlock(&inode->i_lock);
pnfs_send_layoutreturn(lo, stateid, iomode, true);
spin_lock(&inode->i_lock);
} else
/* match pnfs_get_layout_hdr #2 in pnfs_put_lseg */
pnfs_put_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
spin_unlock(&inode->i_lock);
pnfs_free_lseg(lseg);
/* match pnfs_get_layout_hdr #1 in pnfs_put_lseg */
pnfs_put_layout_hdr(lo);
}
static void
pnfs_layoutreturn_free_lseg_async(struct pnfs_layout_segment *lseg)
{
INIT_WORK(&lseg->pls_work, pnfs_layoutreturn_free_lseg);
queue_work(nfsiod_workqueue, &lseg->pls_work);
}
void
pnfs_put_lseg(struct pnfs_layout_segment *lseg)
{
@ -381,21 +417,18 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
lo = lseg->pls_layout;
inode = lo->plh_inode;
if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
bool need_return;
nfs4_stateid stateid;
enum pnfs_iomode iomode;
pnfs_get_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
need_return = pnfs_layout_need_return(lo, lseg,
&stateid, &iomode);
spin_unlock(&inode->i_lock);
pnfs_free_lseg(lseg);
if (need_return)
pnfs_send_layoutreturn(lo, stateid, iomode,
true);
else
if (pnfs_layout_need_return(lo, lseg)) {
spin_unlock(&inode->i_lock);
/* hdr reference dropped in nfs4_layoutreturn_release */
pnfs_get_layout_hdr(lo);
pnfs_layoutreturn_free_lseg_async(lseg);
} else {
pnfs_layout_remove_lseg(lo, lseg);
spin_unlock(&inode->i_lock);
pnfs_free_lseg(lseg);
pnfs_put_layout_hdr(lo);
}
}
}
EXPORT_SYMBOL_GPL(pnfs_put_lseg);
@ -1059,8 +1092,7 @@ bool pnfs_roc(struct inode *ino)
}
spin_unlock(&ino->i_lock);
if (layoutreturn)
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, 0,
NFS4_MAX_UINT64, true);
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
return false;
}
@ -1127,8 +1159,7 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
spin_unlock(&ino->i_lock);
if (layoutreturn) {
rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, 0,
NFS4_MAX_UINT64, false);
pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false);
}
return found;
}