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.
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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