diff options
| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2018-03-07 14:49:06 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2018-03-08 12:56:31 -0500 |
| commit | 9c6376ebddad585da4238532dd6d90ae23ffee67 (patch) | |
| tree | a69494f605f82c0cb19dc8dc63fc65832c6b60dd | |
| parent | d9ee65539d3eabd9ade46cca1780e3309ad0f907 (diff) | |
pNFS: Prevent the layout header refcount going to zero in pnfs_roc()
Ensure that we hold a reference to the layout header when processing
the pNFS return-on-close so that the refcount value does not inadvertently
go to zero.
Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.10+
Tested-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
| -rw-r--r-- | fs/nfs/pnfs.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index c13e826614b5..ee723aa153a3 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -292,8 +292,11 @@ pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo) void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) { - struct inode *inode = lo->plh_inode; + struct inode *inode; + if (!lo) + return; + inode = lo->plh_inode; pnfs_layoutreturn_before_put_layout_hdr(lo); if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) { @@ -1241,10 +1244,12 @@ retry: spin_lock(&ino->i_lock); lo = nfsi->layout; if (!lo || !pnfs_layout_is_valid(lo) || - test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) + test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) { + lo = NULL; goto out_noroc; + } + pnfs_get_layout_hdr(lo); if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) { - pnfs_get_layout_hdr(lo); spin_unlock(&ino->i_lock); wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE); @@ -1312,10 +1317,12 @@ out_noroc: struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld; if (ld->prepare_layoutreturn) ld->prepare_layoutreturn(args); + pnfs_put_layout_hdr(lo); return true; } if (layoutreturn) pnfs_send_layoutreturn(lo, &stateid, iomode, true); + pnfs_put_layout_hdr(lo); return false; } |