xfs: new export ops
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@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c
index 3586c7a..7178d61 100644
--- a/fs/xfs/linux-2.6/xfs_export.c
+++ b/fs/xfs/linux-2.6/xfs_export.c
@@ -33,62 +33,25 @@
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)
+static int xfs_fileid_length(int fileid_type)
{
- 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;
+ 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,
@@ -96,21 +59,21 @@
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
- if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS)) {
- /* 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 (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
+ fileid_type |= XFS_FILEID_TYPE_64FLAG;
/*
* Only encode if there is enough space given. In practice
@@ -118,39 +81,118 @@
* 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);
- p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64);
+ 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);
- type = 2;
+ /*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);
+ 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);
+ /*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 inode *
+xfs_nfs_get_inode(
+ struct super_block *sb,
+ u64 ino,
+ u32 generation)
+ {
+ xfs_fid_t xfid;
+ bhv_vnode_t *vp;
+ int error;
+
+ xfid.fid_len = sizeof(xfs_fid_t) - sizeof(xfid.fid_len);
+ xfid.fid_pad = 0;
+ xfid.fid_ino = ino;
+ xfid.fid_gen = generation;
+
+ error = xfs_vget(XFS_M(sb), &vp, &xfid);
+ if (error)
+ return ERR_PTR(-error);
+
+ return vp ? vn_to_inode(vp) : NULL;
}
STATIC struct dentry *
-xfs_fs_get_dentry(
- struct super_block *sb,
- void *data)
+xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fileid_type)
{
- bhv_vnode_t *vp;
- struct inode *inode;
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
+ struct inode *inode = NULL;
struct dentry *result;
- int error;
- error = xfs_vget(XFS_M(sb), &vp, data);
- if (error || vp == NULL)
- return ERR_PTR(-ESTALE) ;
+ if (fh_len < xfs_fileid_length(fileid_type))
+ return NULL;
- inode = vn_to_inode(vp);
+ 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;
+ }
+
+ if (!inode)
+ return NULL;
+ if (IS_ERR(inode))
+ return ERR_PTR(PTR_ERR(inode));
result = d_alloc_anon(inode);
- if (!result) {
+ 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);
return ERR_PTR(-ENOMEM);
}
@@ -179,8 +221,8 @@
}
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,
};