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-rw-r--r--fs/gfs2/export.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
new file mode 100644
index 00000000000..9200ef22171
--- /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,
+};
+
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-14 16:04:38 +0000