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| author | Weston Andros Adamson <dros@monkey.org> | 2016-06-17 22:48:24 +0200 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2016-06-24 18:01:00 +0200 |
| commit | 5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b (patch) | |
| tree | 71716567b64b5e73b59d7a96a480caac1061e5c6 /fs | |
| parent | nfs4: Fix potential use after free of state in nfs4_do_reclaim. (diff) | |
| download | linux-5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b.tar.xz linux-5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b.zip | |
pnfs_nfs: fix _cancel_empty_pagelist
pnfs_generic_commit_cancel_empty_pagelist calls nfs_commitdata_release,
but that is wrong: nfs_commitdata_release puts the open context, something
that isn't valid until nfs_init_commit is called, which is never the case
when pnfs_generic_commit_cancel_empty_pagelist is called.
This was introduced in "nfs: avoid race that crashes nfs_init_commit".
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/pnfs_nfs.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index 0dfc476da3e1..b38e3c0dc790 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -247,7 +247,11 @@ void pnfs_fetch_commit_bucket_list(struct list_head *pages, } /* Helper function for pnfs_generic_commit_pagelist to catch an empty - * page list. This can happen when two commits race. */ + * page list. This can happen when two commits race. + * + * This must be called instead of nfs_init_commit - call one or the other, but + * not both! + */ static bool pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages, struct nfs_commit_data *data, @@ -256,7 +260,11 @@ pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages, if (list_empty(pages)) { if (atomic_dec_and_test(&cinfo->mds->rpcs_out)) wake_up_atomic_t(&cinfo->mds->rpcs_out); - nfs_commitdata_release(data); + /* don't call nfs_commitdata_release - it tries to put + * the open_context which is not acquired until nfs_init_commit + * which has not been called on @data */ + WARN_ON_ONCE(data->context); + nfs_commit_free(data); return true; } |