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authorPeng Tao <tao.peng@primarydata.com>2014-10-20 10:44:38 +0400
committerTom Haynes <loghyr@primarydata.com>2015-02-03 22:06:50 +0300
commit27b6f53987d61822a858b4680c3727bfb19e620a (patch)
tree78412c8a81e1a51f3fc3ab3b1361ab460f187c9d /fs/nfs
parent193e3aa2ccfb5a53acf7a690b80a1e415b74dbd7 (diff)
downloadlinux-27b6f53987d61822a858b4680c3727bfb19e620a.tar.xz
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>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/pnfs.c81
1 files changed, 56 insertions, 25 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index d3c2ca71a76d..108a619861e5 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -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 @@ out_nolayout:
}
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 @@ out:
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;
}