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>
Acked-by: J. Bruce Fields<bfields@xxxxxxxxxx>
---
fs/nfsd/vfs.c | 15 +++++++++++++--
fs/nfsd/vfs.h | 2 ++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 20fa252..f162dc3 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -785,9 +785,15 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
flags, current_cred());
if (IS_ERR(*filp))
host_err = PTR_ERR(*filp);
- else
+ 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:
@@ -2011,8 +2017,13 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
__be32 err;
struct file *file;
loff_t offset = *offsetp;
+ int may_flags = NFSD_MAY_READ;
+
+ /* NFSv2 only supports 32 bit cookies */
+ if (rqstp->rq_vers > 2)
+ may_flags |= NFSD_MAY_64BIT_COOKIE;
- err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
+ err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
if (err)
goto out;
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 1dcd238..2ac2f3e 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -27,6 +27,8 @@
#define NFSD_MAY_BYPASS_GSS 0x400
#define NFSD_MAY_READ_IF_EXEC 0x800
+#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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