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| author | Scott Mayhew <smayhew@redhat.com> | 2017-12-15 16:12:32 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2018-01-14 23:06:29 -0500 |
| commit | ba4a76f703ab7eb72941fdaac848502073d6e9ee (patch) | |
| tree | d2a7374a5b6e01c3f34f94230e8533c3a0a19616 /fs | |
| parent | b3dce6a2f0601be9b6781b394fdf6ceb63009a44 (diff) | |
| download | linux-ba4a76f703ab7eb72941fdaac848502073d6e9ee.tar.bz2 | |
nfs/pnfs: fix nfs_direct_req ref leak when i/o falls back to the mds
Currently when falling back to doing I/O through the MDS (via
pnfs_{read|write}_through_mds), the client frees the nfs_pgio_header
without releasing the reference taken on the dreq
via pnfs_generic_pg_{read|write}pages -> nfs_pgheader_init ->
nfs_direct_pgio_init. It then takes another reference on the dreq via
nfs_generic_pg_pgios -> nfs_pgheader_init -> nfs_direct_pgio_init and
as a result the requester will become stuck in inode_dio_wait. Once
that happens, other processes accessing the inode will become stuck as
well.
Ensure that pnfs_read_through_mds() and pnfs_write_through_mds() clean
up correctly by calling hdr->completion_ops->completion() instead of
calling hdr->release() directly.
This can be reproduced (sometimes) by performing "storage failover
takeover" commands on NetApp filer while doing direct I/O from a client.
This can also be reproduced using SystemTap to simulate a failure while
doing direct I/O from a client (from Dave Wysochanski
<dwysocha@redhat.com>):
stap -v -g -e 'probe module("nfs_layout_nfsv41_files").function("nfs4_fl_prepare_ds").return { $return=NULL; exit(); }'
Suggested-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Fixes: 1ca018d28d ("pNFS: Fix a memory leak when attempted pnfs fails")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/pnfs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index b3dae6ec2d39..c13e826614b5 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2255,7 +2255,7 @@ pnfs_write_through_mds(struct nfs_pageio_descriptor *desc, nfs_pageio_reset_write_mds(desc); mirror->pg_recoalesce = 1; } - hdr->release(hdr); + hdr->completion_ops->completion(hdr); } static enum pnfs_try_status @@ -2378,7 +2378,7 @@ pnfs_read_through_mds(struct nfs_pageio_descriptor *desc, nfs_pageio_reset_read_mds(desc); mirror->pg_recoalesce = 1; } - hdr->release(hdr); + hdr->completion_ops->completion(hdr); } /* |