diff options
author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-20 20:15:57 -0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-28 16:03:11 -0400 |
commit | 7fdab069b7172f2348cf3d87e19c6c24340292bf (patch) | |
tree | 487de5c39bb8be13be52091acc83139435943000 /fs/nfs/pnfs.c | |
parent | 115ce575cb10918514d053ef15f597a4e6ff60e9 (diff) |
NFSv4.1: Fix a race in the pNFS return-on-close code
If we sleep after dropping the inode->i_lock, then we are no longer
atomic with respect to the rpc_wake_up() call in pnfs_layout_remove_lseg().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/pnfs.c')
-rw-r--r-- | fs/nfs/pnfs.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 9ee3bd705b94..8b32f8745337 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -807,27 +807,29 @@ void pnfs_roc_set_barrier(struct inode *ino, u32 barrier) spin_unlock(&ino->i_lock); } -bool pnfs_roc_drain(struct inode *ino, u32 *barrier) +bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task) { struct nfs_inode *nfsi = NFS_I(ino); + struct pnfs_layout_hdr *lo; struct pnfs_layout_segment *lseg; + u32 current_seqid; bool found = 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; - break; + goto out; } - if (!found) { - struct pnfs_layout_hdr *lo = nfsi->layout; - u32 current_seqid = be32_to_cpu(lo->plh_stateid.seqid); + lo = nfsi->layout; + current_seqid = be32_to_cpu(lo->plh_stateid.seqid); - /* Since close does not return a layout stateid for use as - * a barrier, we choose the worst-case barrier. - */ - *barrier = current_seqid + atomic_read(&lo->plh_outstanding); - } + /* Since close does not return a layout stateid for use as + * a barrier, we choose the worst-case barrier. + */ + *barrier = current_seqid + atomic_read(&lo->plh_outstanding); +out: spin_unlock(&ino->i_lock); return found; } |