Add a structured fid type so that we don't have to pass an array
of u32 values around everywhere. It's a union of possible layouts.
As a start there's only the u32 array and the traditional 32bit
inode format, but there will be more in one of my next patchset
when I start to document the various filehandle formats we have
in lowlevel filesystems better.
Also add an enum that gives the various filehandle types human-
readable names.
Note: Some people might think the struct containing an anonymous
union is ugly, but I didn't want to pass around a raw union type.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6/include/linux/exportfs.h
===================================================================
--- linux-2.6.orig/include/linux/exportfs.h 2007-07-19 15:56:47.000000000 +0200
+++ linux-2.6/include/linux/exportfs.h 2007-07-20 19:50:34.000000000 +0200
@@ -7,6 +7,44 @@ struct dentry;
struct super_block;
struct vfsmount;
+/*
+ * The fileid_type identifies how the file within the filesystem is encoded.
+ * In theory this is freely set and parsed by the filesystem, but we try to
+ * stick to conventions so we can share some generic code and don't confuse
+ * sniffers like ethereal/wireshark.
+ *
+ * The filesystem must not use the value '0' or '0xff'.
+ */
+enum fid_type {
+ /*
+ * The root, or export point, of the filesystem.
+ * (Never actually passed down to the filesystem.
+ */
+ FILEID_ROOT = 0,
+
+ /*
+ * 32bit inode number, 32 bit generation number.
+ */
+ FILEID_INO32_GEN = 1,
+
+ /*
+ * 32bit inode number, 32 bit generation number,
+ * 32 bit parent directory inode number.
+ */
+ FILEID_INO32_GEN_PARENT = 2,
+};
+
+struct fid {
+ union {
+ struct {
+ u32 ino;
+ u32 gen;
+ u32 parent_ino;
+ u32 parent_gen;
+ } i32;
+ __u32 raw[6];
+ };
+};
/**
* struct export_operations - for nfsd to communicate with file systems
@@ -117,9 +155,9 @@ extern struct dentry *find_exported_dent
void *parent, int (*acceptable)(void *context, struct dentry *de),
void *context);
-extern int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
- int connectable);
-extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh,
+extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
+ int *max_len, int connectable);
+extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
int fh_len, int fileid_type, int (*acceptable)(void *, struct dentry *),
void *context);
Index: linux-2.6/fs/nfsd/nfsfh.c
===================================================================
--- linux-2.6.orig/fs/nfsd/nfsfh.c 2007-07-19 15:56:46.000000000 +0200
+++ linux-2.6/fs/nfsd/nfsfh.c 2007-07-20 19:51:49.000000000 +0200
@@ -115,8 +115,7 @@ fh_verify(struct svc_rqst *rqstp, struct
dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
if (!fhp->fh_dentry) {
- __u32 *datap=NULL;
- __u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
+ struct fid *fid = NULL, sfid;
int fileid_type;
int data_left = fh->fh_size/4;
@@ -128,7 +127,6 @@ fh_verify(struct svc_rqst *rqstp, struct
if (fh->fh_version == 1) {
int len;
- datap = fh->fh_auth;
if (--data_left<0) goto out;
switch (fh->fh_auth_type) {
case 0: break;
@@ -144,9 +142,10 @@ fh_verify(struct svc_rqst *rqstp, struct
fh->fh_fsid[1] = fh->fh_fsid[2];
}
if ((data_left -= len)<0) goto out;
- exp = rqst_exp_find(rqstp, fh->fh_fsid_type, datap);
- datap += len;
+ exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
+ fid = (struct fid *)(fh->fh_auth + len);
} else {
+ __u32 tfh[2];
dev_t xdev;
ino_t xino;
if (fh->fh_size != NFS_FHSIZE)
@@ -190,22 +189,22 @@ fh_verify(struct svc_rqst *rqstp, struct
error = nfserr_badhandle;
if (fh->fh_version != 1) {
- tfh[0] = fh->ofh_ino;
- tfh[1] = fh->ofh_generation;
- tfh[2] = fh->ofh_dirino;
- datap = tfh;
+ sfid.i32.ino = fh->ofh_ino;
+ sfid.i32.gen = fh->ofh_generation;
+ sfid.i32.parent_ino = fh->ofh_dirino;
+ fid = &sfid;
data_left = 3;
if (fh->ofh_dirino == 0)
- fileid_type = 1;
+ fileid_type = FILEID_INO32_GEN;
else
- fileid_type = 2;
+ fileid_type = FILEID_INO32_GEN_PARENT;
} else
fileid_type = fh->fh_fileid_type;
- if (fileid_type == 0)
+ if (fileid_type == FILEID_ROOT)
dentry = dget(exp->ex_dentry);
else {
- dentry = exportfs_decode_fh(exp->ex_mnt, datap,
+ dentry = exportfs_decode_fh(exp->ex_mnt, fid,
data_left, fileid_type,
nfsd_acceptable, exp);
}
@@ -286,16 +285,21 @@ out:
* an inode. In this case a call to fh_update should be made
* before the fh goes out on the wire ...
*/
-static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
- __u32 *datap, int *maxsize)
+static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
+ struct dentry *dentry)
{
- if (dentry == exp->ex_dentry) {
- *maxsize = 0;
- return 0;
- }
+ if (dentry != exp->ex_dentry) {
+ struct fid *fid = (struct fid *)
+ (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
+ int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
+ int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
- return exportfs_encode_fh(dentry, datap, maxsize,
- !(exp->ex_flags & NFSEXP_NOSUBTREECHECK));
+ fhp->fh_handle.fh_fileid_type =
+ exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
+ fhp->fh_handle.fh_size += maxsize * 4;
+ } else {
+ fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
+ }
}
/*
@@ -457,12 +461,8 @@ fh_compose(struct svc_fh *fhp, struct sv
datap += len/4;
fhp->fh_handle.fh_size = 4 + len;
- if (inode) {
- int size = (fhp->fh_maxsize-len-4)/4;
- fhp->fh_handle.fh_fileid_type =
- _fh_update(dentry, exp, datap, &size);
- fhp->fh_handle.fh_size += size*4;
- }
+ if (inode)
+ _fh_update(fhp, exp, dentry);
if (fhp->fh_handle.fh_fileid_type == 255)
return nfserr_opnotsupp;
}
@@ -479,7 +479,6 @@ __be32
fh_update(struct svc_fh *fhp)
{
struct dentry *dentry;
- __u32 *datap;
if (!fhp->fh_dentry)
goto out_bad;
@@ -490,15 +489,10 @@ fh_update(struct svc_fh *fhp)
if (fhp->fh_handle.fh_version != 1) {
_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
} else {
- int size;
- if (fhp->fh_handle.fh_fileid_type != 0)
+ if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
goto out;
- datap = fhp->fh_handle.fh_auth+
- fhp->fh_handle.fh_size/4 -1;
- size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
- fhp->fh_handle.fh_fileid_type =
- _fh_update(dentry, fhp->fh_export, datap, &size);
- fhp->fh_handle.fh_size += size*4;
+
+ _fh_update(fhp, fhp->fh_export, dentry);
if (fhp->fh_handle.fh_fileid_type == 255)
return nfserr_opnotsupp;
}
Index: linux-2.6/fs/exportfs/expfs.c
===================================================================
--- linux-2.6.orig/fs/exportfs/expfs.c 2007-07-19 15:56:46.000000000 +0200
+++ linux-2.6/fs/exportfs/expfs.c 2007-07-20 19:50:34.000000000 +0200
@@ -434,29 +434,29 @@ out:
* can be used to check that it is still valid. It places them in the
* filehandle fragment where export_decode_fh expects to find them.
*/
-static int export_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
- int connectable)
+static int export_encode_fh(struct dentry *dentry, struct fid *fid,
+ int *max_len, int connectable)
{
struct inode * inode = dentry->d_inode;
int len = *max_len;
- int type = 1;
+ int type = FILEID_INO32_GEN;
if (len < 2 || (connectable && len < 4))
return 255;
len = 2;
- fh[0] = inode->i_ino;
- fh[1] = inode->i_generation;
+ fid->i32.ino = inode->i_ino;
+ fid->i32.gen = inode->i_generation;
if (connectable && !S_ISDIR(inode->i_mode)) {
struct inode *parent;
spin_lock(&dentry->d_lock);
parent = dentry->d_parent->d_inode;
- fh[2] = parent->i_ino;
- fh[3] = parent->i_generation;
+ fid->i32.parent_ino = parent->i_ino;
+ fid->i32.parent_gen = parent->i_generation;
spin_unlock(&dentry->d_lock);
len = 4;
- type = 2;
+ type = FILEID_INO32_GEN_PARENT;
}
*max_len = len;
return type;
@@ -494,33 +494,33 @@ static struct dentry *export_decode_fh(s
acceptable, context);
}
-int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
+int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
int connectable)
{
struct export_operations *nop = dentry->d_sb->s_export_op;
int error;
if (nop->encode_fh)
- error = nop->encode_fh(dentry, fh, max_len, connectable);
+ error = nop->encode_fh(dentry, fid->raw, max_len, connectable);
else
- error = export_encode_fh(dentry, fh, max_len, connectable);
+ error = export_encode_fh(dentry, fid, max_len, connectable);
return error;
}
EXPORT_SYMBOL_GPL(exportfs_encode_fh);
-struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh, int fh_len,
- int fileid_type, int (*acceptable)(void *, struct dentry *),
- void *context)
+struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
+ int fh_len, int fileid_type,
+ int (*acceptable)(void *, struct dentry *), void *context)
{
struct export_operations *nop = mnt->mnt_sb->s_export_op;
struct dentry *result;
if (nop->decode_fh) {
- result = nop->decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
+ result = nop->decode_fh(mnt->mnt_sb, fid->raw, fh_len, fileid_type,
acceptable, context);
} else {
- result = export_decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
+ result = export_decode_fh(mnt->mnt_sb, fid->raw, fh_len, fileid_type,
acceptable, context);
}
--
-
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