1 files changed, 285 insertions, 0 deletions

diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
new file mode 100644
index 000000000000..9200ef221716
--- /dev/null
+++ b/fs/gfs2/export.c
@@ -0,0 +1,285 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/exportfs.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/crc32.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "dir.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "super.h"
+#include "rgrp.h"
+#include "util.h"
+
+#define GFS2_SMALL_FH_SIZE 4
+#define GFS2_LARGE_FH_SIZE 8
+#define GFS2_OLD_FH_SIZE 10
+
+static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
+                          int connectable)
+{
+        __be32 *fh = (__force __be32 *)p;
+        struct inode *inode = dentry->d_inode;
+        struct super_block *sb = inode->i_sb;
+        struct gfs2_inode *ip = GFS2_I(inode);
+
+        if (*len < GFS2_SMALL_FH_SIZE ||
+            (connectable && *len < GFS2_LARGE_FH_SIZE))
+                return 255;
+
+        fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
+        fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
+        fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
+        fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
+        *len = GFS2_SMALL_FH_SIZE;
+
+        if (!connectable || inode == sb->s_root->d_inode)
+                return *len;
+
+        spin_lock(&dentry->d_lock);
+        inode = dentry->d_parent->d_inode;
+        ip = GFS2_I(inode);
+        igrab(inode);
+        spin_unlock(&dentry->d_lock);
+
+        fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
+        fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
+        fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
+        fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
+        *len = GFS2_LARGE_FH_SIZE;
+
+        iput(inode);
+
+        return *len;
+}
+
+struct get_name_filldir {
+        struct gfs2_inum_host inum;
+        char *name;
+};
+
+static int get_name_filldir(void *opaque, const char *name, int length,
+                            loff_t offset, u64 inum, unsigned int type)
+{
+        struct get_name_filldir *gnfd = opaque;
+
+        if (inum != gnfd->inum.no_addr)
+                return 0;
+
+        memcpy(gnfd->name, name, length);
+        gnfd->name[length] = 0;
+
+        return 1;
+}
+
+static int gfs2_get_name(struct dentry *parent, char *name,
+                         struct dentry *child)
+{
+        struct inode *dir = parent->d_inode;
+        struct inode *inode = child->d_inode;
+        struct gfs2_inode *dip, *ip;
+        struct get_name_filldir gnfd;
+        struct gfs2_holder gh;
+        u64 offset = 0;
+        int error;
+
+        if (!dir)
+                return -EINVAL;
+
+        if (!S_ISDIR(dir->i_mode) || !inode)
+                return -EINVAL;
+
+        dip = GFS2_I(dir);
+        ip = GFS2_I(inode);
+
+        *name = 0;
+        gnfd.inum.no_addr = ip->i_no_addr;
+        gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
+        gnfd.name = name;
+
+        error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
+        if (error)
+                return error;
+
+        error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
+
+        gfs2_glock_dq_uninit(&gh);
+
+        if (!error && !*name)
+                error = -ENOENT;
+
+        return error;
+}
+
+static struct dentry *gfs2_get_parent(struct dentry *child)
+{
+        struct qstr dotdot;
+        struct dentry *dentry;
+
+        /*
+         * XXX(hch): it would be a good idea to keep this around as a
+         *           static variable.
+         */
+        gfs2_str2qstr(&dotdot, "..");
+
+        dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
+        if (!IS_ERR(dentry))
+                dentry->d_op = &gfs2_dops;
+        return dentry;
+}
+
+static struct dentry *gfs2_get_dentry(struct super_block *sb,
+                struct gfs2_inum_host *inum)
+{
+        struct gfs2_sbd *sdp = sb->s_fs_info;
+        struct gfs2_holder i_gh, ri_gh, rgd_gh;
+        struct gfs2_rgrpd *rgd;
+        struct inode *inode;
+        struct dentry *dentry;
+        int error;
+
+        /* System files? */
+
+        inode = gfs2_ilookup(sb, inum->no_addr);
+        if (inode) {
+                if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
+                        iput(inode);
+                        return ERR_PTR(-ESTALE);
+                }
+                goto out_inode;
+        }
+
+        error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
+                                  LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
+        if (error)
+                return ERR_PTR(error);
+
+        error = gfs2_rindex_hold(sdp, &ri_gh);
+        if (error)
+                goto fail;
+
+        error = -EINVAL;
+        rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
+        if (!rgd)
+                goto fail_rindex;
+
+        error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
+        if (error)
+                goto fail_rindex;
+
+        error = -ESTALE;
+        if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
+                goto fail_rgd;
+
+        gfs2_glock_dq_uninit(&rgd_gh);
+        gfs2_glock_dq_uninit(&ri_gh);
+
+        inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
+                                        inum->no_addr,
+                                        0, 0);
+        if (IS_ERR(inode)) {
+                error = PTR_ERR(inode);
+                goto fail;
+        }
+
+        error = gfs2_inode_refresh(GFS2_I(inode));
+        if (error) {
+                iput(inode);
+                goto fail;
+        }
+
+        /* Pick up the works we bypass in gfs2_inode_lookup */
+        if (inode->i_state & I_NEW) 
+                gfs2_set_iop(inode);
+
+        if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
+                iput(inode);
+                goto fail;
+        }
+
+        error = -EIO;
+        if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
+                iput(inode);
+                goto fail;
+        }
+
+        gfs2_glock_dq_uninit(&i_gh);
+
+out_inode:
+        dentry = d_obtain_alias(inode);
+        if (!IS_ERR(dentry))
+                dentry->d_op = &gfs2_dops;
+        return dentry;
+
+fail_rgd:
+        gfs2_glock_dq_uninit(&rgd_gh);
+
+fail_rindex:
+        gfs2_glock_dq_uninit(&ri_gh);
+
+fail:
+        gfs2_glock_dq_uninit(&i_gh);
+        return ERR_PTR(error);
+}
+
+static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+                int fh_len, int fh_type)
+{
+        struct gfs2_inum_host this;
+        __be32 *fh = (__force __be32 *)fid->raw;
+
+        switch (fh_type) {
+        case GFS2_SMALL_FH_SIZE:
+        case GFS2_LARGE_FH_SIZE:
+        case GFS2_OLD_FH_SIZE:
+                this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
+                this.no_formal_ino |= be32_to_cpu(fh[1]);
+                this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
+                this.no_addr |= be32_to_cpu(fh[3]);
+                return gfs2_get_dentry(sb, &this);
+        default:
+                return NULL;
+        }
+}
+
+static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
+                int fh_len, int fh_type)
+{
+        struct gfs2_inum_host parent;
+        __be32 *fh = (__force __be32 *)fid->raw;
+
+        switch (fh_type) {
+        case GFS2_LARGE_FH_SIZE:
+        case GFS2_OLD_FH_SIZE:
+                parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
+                parent.no_formal_ino |= be32_to_cpu(fh[5]);
+                parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
+                parent.no_addr |= be32_to_cpu(fh[7]);
+                return gfs2_get_dentry(sb, &parent);
+        default:
+                return NULL;
+        }
+}
+
+const struct export_operations gfs2_export_ops = {
+        .encode_fh = gfs2_encode_fh,
+        .fh_to_dentry = gfs2_fh_to_dentry,
+        .fh_to_parent = gfs2_fh_to_parent,
+        .get_name = gfs2_get_name,
+        .get_parent = gfs2_get_parent,
+};
+