On Mon, Aug 08, 2011 at 05:38:13PM +0200, Bernd Schubert wrote:
> Use 32-bit or 64-bit llseek() hashes for directory offsets depending on
> the NFS version. NFSv2 gets 32-bit hashes only.
>
> NOTE: This patch got rather complex as Christoph asked to set the
> filp->f_mode flag in the open call or immediatly after dentry_open()
> in nfsd_open() to avoid races.
> Personally I still do not see a reason for that and in my opinion
> FMODE_32BITHASH/FMODE_64BITHASH flags could be set nfsd_readdir(), as it
> follows directly after nfsd_open() without a chance of races.
The bulk of the patch seems to be just an access->may_flags rename.
Could you please split that into a separate patch?
--b.
>
>
> Signed-off-by: Bernd Schubert <bernd.schubert@xxxxxxxxxxxxxxxxxx>
> ---
> fs/nfsd/vfs.c | 33 +++++++++++++++++++++++----------
> fs/nfsd/vfs.h | 2 ++
> 2 files changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index fd0acca..4bb517f 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -708,12 +708,13 @@ static int nfsd_open_break_lease(struct inode *inode, int access)
>
> /*
> * Open an existing file or directory.
> - * The access argument indicates the type of open (read/write/lock)
> + * The may_flags argument indicates the type of open (read/write/lock)
> + * and additional flags.
> * N.B. After this call fhp needs an fh_put
> */
> __be32
> nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> - int access, struct file **filp)
> + int may_flags, struct file **filp)
> {
> struct dentry *dentry;
> struct inode *inode;
> @@ -728,7 +729,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> * and (hopefully) checked permission - so allow OWNER_OVERRIDE
> * in case a chmod has now revoked permission.
> */
> - err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE);
> + err = fh_verify(rqstp, fhp, type, may_flags | NFSD_MAY_OWNER_OVERRIDE);
> if (err)
> goto out;
>
> @@ -739,7 +740,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> * or any access when mandatory locking enabled
> */
> err = nfserr_perm;
> - if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE))
> + if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
> goto out;
> /*
> * We must ignore files (but only files) which might have mandatory
> @@ -752,12 +753,12 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> if (!inode->i_fop)
> goto out;
>
> - host_err = nfsd_open_break_lease(inode, access);
> + host_err = nfsd_open_break_lease(inode, may_flags);
> if (host_err) /* NOMEM or WOULDBLOCK */
> goto out_nfserr;
>
> - if (access & NFSD_MAY_WRITE) {
> - if (access & NFSD_MAY_READ)
> + if (may_flags & NFSD_MAY_WRITE) {
> + if (may_flags & NFSD_MAY_READ)
> flags = O_RDWR|O_LARGEFILE;
> else
> flags = O_WRONLY|O_LARGEFILE;
> @@ -766,8 +767,15 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> flags, current_cred());
> if (IS_ERR(*filp))
> host_err = PTR_ERR(*filp);
> - else
> - host_err = ima_file_check(*filp, access);
> + else {
> + host_err = ima_file_check(*filp, may_flags);
> +
> + if (may_flags & NFSD_MAY_64BIT_COOKIE)
> + (*filp)->f_mode |= FMODE_64BITHASH;
> + else
> + (*filp)->f_mode |= FMODE_32BITHASH;
> + }
> +
> out_nfserr:
> err = nfserrno(host_err);
> out:
> @@ -1989,8 +1997,13 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
> __be32 err;
> struct file *file;
> loff_t offset = *offsetp;
> + int flags = NFSD_MAY_READ;
> +
> + /* NFSv2 only supports 32 bit cookies */
> + if (rqstp->rq_vers > 2)
> + flags |= NFSD_MAY_64BIT_COOKIE;
>
> - err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
> + err = nfsd_open(rqstp, fhp, S_IFDIR, flags, &file);
> if (err)
> goto out;
>
> diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
> index e0bbac0..ecd00e1 100644
> --- a/fs/nfsd/vfs.h
> +++ b/fs/nfsd/vfs.h
> @@ -26,6 +26,8 @@
> #define NFSD_MAY_NOT_BREAK_LEASE 512
> #define NFSD_MAY_BYPASS_GSS 1024
>
> +#define NFSD_MAY_64BIT_COOKIE 2048 /* 64 bit readdir cookies for >= NFSv3 */
> +
> #define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE)
> #define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
>
>
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