lkml.org 
[lkml]   [2009]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    Subject[PATCH] nfsd: Ensure nfsv4 calls the underlying filesystem on LOCKT
    From
    From: J. Bruce Fields <bfields@citi.umich.edu>

    Since nfsv4 allows LOCKT without an open, but the ->lock() method is a
    file method, we fake up a struct file in the nfsv4 code with just the
    fields we need initialized. But we forgot to initialize the file
    operations, with the result that LOCKT never results in a call to the
    filesystem's ->lock() method (if it exists).

    We could just add that one more initialization. But this hack of faking
    up a struct file with only some fields initialized seems the kind of
    thing that might cause more problems in the future. We should either do
    an open and get a real struct file, or make lock-testing an inode (not a
    file) method.

    This patch does the former.

    Reported-by: Marc Eshel <eshel@almaden.ibm.com>
    Tested-by: Marc Eshel <eshel@almaden.ibm.com>
    Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
    ---
    fs/nfsd/nfs4state.c | 30 ++++++++++++++++++++----------
    1 files changed, 20 insertions(+), 10 deletions(-)

    diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
    index 06b89df..e62d0e3 100644
    --- a/fs/nfsd/nfs4state.c
    +++ b/fs/nfsd/nfs4state.c
    @@ -2782,6 +2782,25 @@ out:
    }

    /*
    + * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
    + * so we do a temporary open here just to get an open file to pass to
    + * vfs_test_lock. (Arguably perhaps test_lock should be done with an
    + * inode operation.)
    + */
    +static int nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
    +{
    + struct file *file;
    + int err;
    +
    + err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
    + if (err)
    + return err;
    + err = vfs_test_lock(file, lock);
    + nfsd_close(file);
    + return err;
    +}
    +
    +/*
    * LOCKT operation
    */
    __be32
    @@ -2789,7 +2808,6 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
    struct nfsd4_lockt *lockt)
    {
    struct inode *inode;
    - struct file file;
    struct file_lock file_lock;
    int error;
    __be32 status;
    @@ -2847,16 +2865,8 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,

    nfs4_transform_lock_offset(&file_lock);

    - /* vfs_test_lock uses the struct file _only_ to resolve the inode.
    - * since LOCKT doesn't require an OPEN, and therefore a struct
    - * file may not exist, pass vfs_test_lock a struct file with
    - * only the dentry:inode set.
    - */
    - memset(&file, 0, sizeof (struct file));
    - file.f_path.dentry = cstate->current_fh.fh_dentry;
    -
    status = nfs_ok;
    - error = vfs_test_lock(&file, &file_lock);
    + error = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock);
    if (error) {
    status = nfserrno(error);
    goto out;
    --
    1.5.6.3


    \
     
     \ /
      Last update: 2009-01-28 00:27    [W:0.024 / U:32.664 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site