diff options
| author | Oleg Drokin <green@linuxhacker.ru> | 2016-06-14 23:28:05 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2016-06-15 22:03:41 -0400 |
| commit | 5cc1fb2a093e254b656c64ff24b0b76bed1d34d9 (patch) | |
| tree | f37829299f97a6ab668ec0ec77bf00af101ae5be /fs/nfsd/nfs4state.c | |
| parent | feb9dad5209280085d5b0c094fa67e7a8d75c81a (diff) | |
| download | linux-exynos-5cc1fb2a093e254b656c64ff24b0b76bed1d34d9.tar.gz linux-exynos-5cc1fb2a093e254b656c64ff24b0b76bed1d34d9.tar.bz2 linux-exynos-5cc1fb2a093e254b656c64ff24b0b76bed1d34d9.zip | |
nfsd: Extend the mutex holding region around in nfsd4_process_open2()
To avoid racing entry into nfs4_get_vfs_file().
Make init_open_stateid() return with locked stateid to be unlocked
by the caller.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd/nfs4state.c')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index c927d36d8ac6..94854a06c9ad 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3487,6 +3487,10 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, struct nfs4_openowner *oo = open->op_openowner; struct nfs4_ol_stateid *retstp = NULL; + /* We are moving these outside of the spinlocks to avoid the warnings */ + mutex_init(&stp->st_mutex); + mutex_lock(&stp->st_mutex); + spin_lock(&oo->oo_owner.so_client->cl_lock); spin_lock(&fp->fi_lock); @@ -3502,13 +3506,17 @@ init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, stp->st_access_bmap = 0; stp->st_deny_bmap = 0; stp->st_openstp = NULL; - mutex_init(&stp->st_mutex); list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids); list_add(&stp->st_perfile, &fp->fi_stateids); out_unlock: spin_unlock(&fp->fi_lock); spin_unlock(&oo->oo_owner.so_client->cl_lock); + if (retstp) { + mutex_lock(&retstp->st_mutex); + /* Not that we need to, just for neatness */ + mutex_unlock(&stp->st_mutex); + } return retstp; } @@ -4344,11 +4352,14 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf } else { stp = open->op_stp; open->op_stp = NULL; + /* + * init_open_stateid() either returns a locked stateid + * it found, or initializes and locks the new one we passed in + */ swapstp = init_open_stateid(stp, fp, open); if (swapstp) { nfs4_put_stid(&stp->st_stid); stp = swapstp; - mutex_lock(&stp->st_mutex); status = nfs4_upgrade_open(rqstp, fp, current_fh, stp, open); if (status) { @@ -4357,7 +4368,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf } goto upgrade_out; } - mutex_lock(&stp->st_mutex); status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open); if (status) { mutex_unlock(&stp->st_mutex); |