This one is a lot more complicated than the previous ones. XFS already
had a very clever scheme for supporting 64bit inode numbers in filehandles,
and I've reworked this to be some kind of a prototype for the generic
64bit inode filehandle support.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6/fs/xfs/linux-2.6/xfs_export.c
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_export.c 2007-09-13 15:17:07.000000000 +0200
+++ linux-2.6/fs/xfs/linux-2.6/xfs_export.c 2007-09-13 15:20:49.000000000 +0200
@@ -27,62 +27,25 @@
static struct dentry dotdot = { .d_name.name = "..", .d_name.len = 2, };
/*
- * XFS encodes and decodes the fileid portion of NFS filehandles
- * itself instead of letting the generic NFS code do it. This
- * allows filesystems with 64 bit inode numbers to be exported.
- *
- * Note that a side effect is that xfs_vget() won't be passed a
- * zero inode/generation pair under normal circumstances. As
- * however a malicious client could send us such data, the check
- * remains in that code.
+ * Note that we only accept fileids which are long enough rather than allow
+ * the parent generation number to default to zero. XFS considers zero a
+ * valid generation number not an invalid/wildcard value.
*/
-
-STATIC struct dentry *
-xfs_fs_decode_fh(
- struct super_block *sb,
- __u32 *fh,
- int fh_len,
- int fileid_type,
- int (*acceptable)(
- void *context,
- struct dentry *de),
- void *context)
-{
- xfs_fid_t ifid;
- xfs_fid_t pfid;
- void *parent = NULL;
- int is64 = 0;
- __u32 *p = fh;
-
-#if XFS_BIG_INUMS
- is64 = (fileid_type & XFS_FILEID_TYPE_64FLAG);
- fileid_type &= ~XFS_FILEID_TYPE_64FLAG;
-#endif
-
- /*
- * Note that we only accept fileids which are long enough
- * rather than allow the parent generation number to default
- * to zero. XFS considers zero a valid generation number not
- * an invalid/wildcard value. There's little point printk'ing
- * a warning here as we don't have the client information
- * which would make such a warning useful.
- */
- if (fileid_type > 2 ||
- fh_len < xfs_fileid_length((fileid_type == 2), is64))
- return NULL;
-
- p = xfs_fileid_decode_fid2(p, &ifid, is64);
-
- if (fileid_type == 2) {
- p = xfs_fileid_decode_fid2(p, &pfid, is64);
- parent = &pfid;
+static int xfs_fileid_length(int fileid_type)
+{
+ switch (fileid_type) {
+ case FILEID_INO32_GEN:
+ return 2;
+ case FILEID_INO32_GEN_PARENT:
+ return 4;
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ return 3;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ return 6;
}
-
- fh = (__u32 *)&ifid;
- return sb->s_export_op->find_exported_dentry(sb, fh, parent, acceptable, context);
+ return 255; /* invalid */
}
-
STATIC int
xfs_fs_encode_fh(
struct dentry *dentry,
@@ -90,23 +53,23 @@ xfs_fs_encode_fh(
int *max_len,
int connectable)
{
+ struct fid *fid = (struct fid *)fh;
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
struct inode *inode = dentry->d_inode;
- int type = 1;
- __u32 *p = fh;
+ int fileid_type;
int len;
- int is64 = 0;
-#if XFS_BIG_INUMS
bhv_vfs_t *vfs = vfs_from_sb(inode->i_sb);
- if (!(vfs->vfs_flag & VFS_32BITINODES)) {
- /* filesystem may contain 64bit inode numbers */
- is64 = XFS_FILEID_TYPE_64FLAG;
- }
-#endif
/* Directories don't need their parent encoded, they have ".." */
if (S_ISDIR(inode->i_mode))
- connectable = 0;
+ fileid_type = FILEID_INO32_GEN;
+ else
+ fileid_type = FILEID_INO32_GEN_PARENT;
+
+ /* filesystem may contain 64bit inode numbers */
+ if (!(vfs->vfs_flag & VFS_32BITINODES))
+ fileid_type |= XFS_FILEID_TYPE_64FLAG;
/*
* Only encode if there is enough space given. In practice
@@ -114,38 +77,116 @@ xfs_fs_encode_fh(
* over NFSv2 with the subtree_check export option; the other
* seven combinations work. The real answer is "don't use v2".
*/
- len = xfs_fileid_length(connectable, is64);
+ len = xfs_fileid_length(fileid_type);
if (*max_len < len)
return 255;
*max_len = len;
- p = xfs_fileid_encode_inode(p, inode, is64);
- if (connectable) {
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ spin_lock(&dentry->d_lock);
+ fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
+ fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
+ spin_unlock(&dentry->d_lock);
+ /*FALLTHRU*/
+ case FILEID_INO32_GEN:
+ fid->i32.ino = inode->i_ino;
+ fid->i32.gen = inode->i_generation;
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
spin_lock(&dentry->d_lock);
- p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64);
+ fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
+ fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
spin_unlock(&dentry->d_lock);
- type = 2;
+ /*FALLTHRU*/
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ fid64->ino = inode->i_ino;
+ fid64->gen = inode->i_generation;
+ break;
}
- BUG_ON((p - fh) != len);
- return type | is64;
+
+ return fileid_type;
}
-STATIC struct dentry *
-xfs_fs_get_dentry(
+STATIC struct inode *
+xfs_nfs_get_inode(
struct super_block *sb,
- void *data)
+ u64 ino,
+ u32 generation)
{
+ xfs_fid_t xfid;
bhv_vnode_t *vp;
- struct inode *inode;
- struct dentry *result;
- bhv_vfs_t *vfsp = vfs_from_sb(sb);
int error;
- error = bhv_vfs_vget(vfsp, &vp, data);
- if (error || vp == NULL)
- return ERR_PTR(-ESTALE) ;
+ xfid.fid_len = sizeof(xfs_fid_t) - sizeof(xfid.fid_len);
+ xfid.fid_pad = 0;
+ xfid.fid_ino = ino;
+ xfid.fid_gen = generation;
+
+ error = bhv_vfs_vget(vfs_from_sb(sb), &vp, &xfid);
+ if (error)
+ return ERR_PTR(-error);
+
+ return vp ? vn_to_inode(vp) : NULL;
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fileid_type)
+{
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
+ struct inode *inode = NULL;
+ struct dentry *result;
+
+ if (fh_len < xfs_fileid_length(fileid_type))
+ return NULL;
+
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ case FILEID_INO32_GEN:
+ inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
+ break;
+ }
- inode = vn_to_inode(vp);
+ if (!inode)
+ return NULL;
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
+ result = d_alloc_anon(inode);
+ if (!result) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+ return result;
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fileid_type)
+{
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
+ struct inode *inode = NULL;
+ struct dentry *result;
+
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
+ fid->i32.parent_gen);
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
+ fid64->parent_gen);
+ break;
+ }
+
+ if (!inode)
+ return NULL;
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
result = d_alloc_anon(inode);
if (!result) {
iput(inode);
@@ -177,8 +218,8 @@ xfs_fs_get_parent(
}
struct export_operations xfs_export_operations = {
- .decode_fh = xfs_fs_decode_fh,
.encode_fh = xfs_fs_encode_fh,
+ .fh_to_dentry = xfs_fs_fh_to_dentry,
+ .fh_to_parent = xfs_fs_fh_to_parent,
.get_parent = xfs_fs_get_parent,
- .get_dentry = xfs_fs_get_dentry,
};
Index: linux-2.6/fs/xfs/linux-2.6/xfs_export.h
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_export.h 2007-09-13 15:17:07.000000000 +0200
+++ linux-2.6/fs/xfs/linux-2.6/xfs_export.h 2007-09-13 15:20:19.000000000 +0200
@@ -59,50 +59,14 @@
* a subdirectory) or use the "fsid" export option.
*/
+struct xfs_fid64 {
+ u64 ino;
+ u32 gen;
+ u64 parent_ino;
+ u32 parent_gen;
+} __attribute__((packed));
+
/* This flag goes on the wire. Don't play with it. */
#define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */
-/* Calculate the length in u32 units of the fileid data */
-static inline int
-xfs_fileid_length(int hasparent, int is64)
-{
- return hasparent ? (is64 ? 6 : 4) : (is64 ? 3 : 2);
-}
-
-/*
- * Decode encoded inode information (either for the inode itself
- * or the parent) into an xfs_fid_t structure. Advances and
- * returns the new data pointer
- */
-static inline __u32 *
-xfs_fileid_decode_fid2(__u32 *p, xfs_fid_t *fid, int is64)
-{
- fid->fid_len = sizeof(xfs_fid_t) - sizeof(fid->fid_len);
- fid->fid_pad = 0;
- fid->fid_ino = *p++;
-#if XFS_BIG_INUMS
- if (is64)
- fid->fid_ino |= (((__u64)(*p++)) << 32);
-#endif
- fid->fid_gen = *p++;
- return p;
-}
-
-/*
- * Encode inode information (either for the inode itself or the
- * parent) into a fileid buffer. Advances and returns the new
- * data pointer.
- */
-static inline __u32 *
-xfs_fileid_encode_inode(__u32 *p, struct inode *inode, int is64)
-{
- *p++ = (__u32)inode->i_ino;
-#if XFS_BIG_INUMS
- if (is64)
- *p++ = (__u32)(inode->i_ino >> 32);
-#endif
- *p++ = inode->i_generation;
- return p;
-}
-
#endif /* __XFS_EXPORT_H__ */
--
-
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