[069/107] NFSv4.1: allow nfs_fhget to succeed with mounted on fileid

From: Greg KH
Date: Fri Jul 08 2011 - 01:04:16 EST


2.6.39-stable review patch. If anyone has any objections, please let us know.

------------------

From: Andy Adamson <andros@xxxxxxxxxx>

commit 533eb4611c9eea53072eb6a61d5a6393b6a77ed7 upstream.

Commit 28331a46d88459788c8fca72dbb0415cd7f514c9 "Ensure we request the
ordinary fileid when doing readdirplus"
changed the meaning of NFS_ATTR_FATTR_FILEID which used to be set when
FATTR4_WORD1_MOUNTED_ON_FILED was requested.

Allow nfs_fhget to succeed with only a mounted on fileid when crossing
a mountpoint or a referral.

Ask for the fileid of the absent file system if mounted_on_fileid is not
supported.

Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/nfs/inode.c | 3 ++-
fs/nfs/internal.h | 11 +++++++++++
fs/nfs/nfs4proc.c | 33 +++++++++++++++++++++++----------
3 files changed, 36 insertions(+), 11 deletions(-)

--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -256,7 +256,8 @@ nfs_fhget(struct super_block *sb, struct

nfs_attr_check_mountpoint(sb, fattr);

- if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0 && (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0)
+ if (((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0) &&
+ !nfs_attr_use_mounted_on_fileid(fattr))
goto out_no_inode;
if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
goto out_no_inode;
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -45,6 +45,17 @@ static inline void nfs_attr_check_mountp
fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
}

+static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
+{
+ if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
+ (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
+ ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
+ return 0;
+
+ fattr->fileid = fattr->mounted_on_fileid;
+ return 1;
+}
+
struct nfs_clone_mount {
const struct super_block *sb;
const struct dentry *dentry;
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2265,12 +2265,14 @@ static int nfs4_proc_get_root(struct nfs
return nfs4_map_errors(status);
}

+static void nfs_fixup_referral_attributes(struct nfs_fattr *fattr);
/*
* Get locations and (maybe) other attributes of a referral.
* Note that we'll actually follow the referral later when
* we detect fsid mismatch in inode revalidation
*/
-static int nfs4_get_referral(struct inode *dir, const struct qstr *name, struct nfs_fattr *fattr, struct nfs_fh *fhandle)
+static int nfs4_get_referral(struct inode *dir, const struct qstr *name,
+ struct nfs_fattr *fattr, struct nfs_fh *fhandle)
{
int status = -ENOMEM;
struct page *page = NULL;
@@ -2288,15 +2290,16 @@ static int nfs4_get_referral(struct inod
goto out;
/* Make sure server returned a different fsid for the referral */
if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &locations->fattr.fsid)) {
- dprintk("%s: server did not return a different fsid for a referral at %s\n", __func__, name->name);
+ dprintk("%s: server did not return a different fsid for"
+ " a referral at %s\n", __func__, name->name);
status = -EIO;
goto out;
}
+ /* Fixup attributes for the nfs_lookup() call to nfs_fhget() */
+ nfs_fixup_referral_attributes(&locations->fattr);

+ /* replace the lookup nfs_fattr with the locations nfs_fattr */
memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr));
- fattr->valid |= NFS_ATTR_FATTR_V4_REFERRAL;
- if (!fattr->mode)
- fattr->mode = S_IFDIR;
memset(fhandle, 0, sizeof(struct nfs_fh));
out:
if (page)
@@ -4657,11 +4660,15 @@ static size_t nfs4_xattr_list_nfs4_acl(s
return len;
}

+/*
+ * nfs_fhget will use either the mounted_on_fileid or the fileid
+ */
static void nfs_fixup_referral_attributes(struct nfs_fattr *fattr)
{
- if (!((fattr->valid & NFS_ATTR_FATTR_FILEID) &&
- (fattr->valid & NFS_ATTR_FATTR_FSID) &&
- (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)))
+ if (!(((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) ||
+ (fattr->valid & NFS_ATTR_FATTR_FILEID)) &&
+ (fattr->valid & NFS_ATTR_FATTR_FSID) &&
+ (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)))
return;

fattr->valid |= NFS_ATTR_FATTR_TYPE | NFS_ATTR_FATTR_MODE |
@@ -4676,7 +4683,6 @@ int nfs4_proc_fs_locations(struct inode
struct nfs_server *server = NFS_SERVER(dir);
u32 bitmask[2] = {
[0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
- [1] = FATTR4_WORD1_MOUNTED_ON_FILEID,
};
struct nfs4_fs_locations_arg args = {
.dir_fh = NFS_FH(dir),
@@ -4695,11 +4701,18 @@ int nfs4_proc_fs_locations(struct inode
int status;

dprintk("%s: start\n", __func__);
+
+ /* Ask for the fileid of the absent filesystem if mounted_on_fileid
+ * is not supported */
+ if (NFS_SERVER(dir)->attr_bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)
+ bitmask[1] |= FATTR4_WORD1_MOUNTED_ON_FILEID;
+ else
+ bitmask[0] |= FATTR4_WORD0_FILEID;
+
nfs_fattr_init(&fs_locations->fattr);
fs_locations->server = server;
fs_locations->nlocations = 0;
status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
- nfs_fixup_referral_attributes(&fs_locations->fattr);
dprintk("%s: returned status = %d\n", __func__, status);
return status;
}


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