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| author | Peng Tao <tao.peng@primarydata.com> | 2015-01-20 07:44:29 +0800 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-02-08 20:01:58 +0100 |
| commit | 88bc02271ea706c54abf4237744436c5982d09bf (patch) | |
| tree | b693ec90ca4286c4ecbcd19bbadb9c8e8e7983ec /fs | |
| parent | 6633edfec196ef3a3f0a5cd4bbcdb1c65c532694 (diff) | |
| download | lwn-88bc02271ea706c54abf4237744436c5982d09bf.tar.gz lwn-88bc02271ea706c54abf4237744436c5982d09bf.zip | |
nfs: fix dio deadlock when O_DIRECT flag is flipped
commit ee8a1a8b160a87dc3a9c81a86796aa4db85ea815 upstream.
We only support swap file calling nfs_direct_IO. However, application
might be able to get to nfs_direct_IO if it toggles O_DIRECT flag
during IO and it can deadlock because we grab inode->i_mutex in
nfs_file_direct_write(). So return 0 for such case. Then the generic
layer will fall back to buffer IO.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/direct.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index d751a2383c24..db6245c1cd33 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -123,6 +123,12 @@ static inline int put_dreq(struct nfs_direct_req *dreq) */ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) { + struct inode *inode = iocb->ki_filp->f_mapping->host; + + /* we only support swap file calling nfs_direct_IO */ + if (!IS_SWAPFILE(inode)) + return 0; + #ifndef CONFIG_NFS_SWAP dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", iocb->ki_filp->f_path.dentry->d_name.name, |