--- /dev/null
+/*
+ * Copyright (C) 2005-2011 Junjiro R. Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * export via nfs
+ */
+
+#include <linux/exportfs.h>
+#include <linux/file.h>
+#include <linux/mnt_namespace.h>
+#include <linux/namei.h>
+#include <linux/nsproxy.h>
+#include <linux/random.h>
+#include <linux/writeback.h>
+#include "aufs.h"
+
+union conv {
+#ifdef CONFIG_AUFS_INO_T_64
+ __u32 a[2];
+#else
+ __u32 a[1];
+#endif
+ ino_t ino;
+};
+
+static ino_t decode_ino(__u32 *a)
+{
+ union conv u;
+
+ BUILD_BUG_ON(sizeof(u.ino) != sizeof(u.a));
+ u.a[0] = a[0];
+#ifdef CONFIG_AUFS_INO_T_64
+ u.a[1] = a[1];
+#endif
+ return u.ino;
+}
+
+static void encode_ino(__u32 *a, ino_t ino)
+{
+ union conv u;
+
+ u.ino = ino;
+ a[0] = u.a[0];
+#ifdef CONFIG_AUFS_INO_T_64
+ a[1] = u.a[1];
+#endif
+}
+
+/* NFS file handle */
+enum {
+ Fh_br_id,
+ Fh_sigen,
+#ifdef CONFIG_AUFS_INO_T_64
+ /* support 64bit inode number */
+ Fh_ino1,
+ Fh_ino2,
+ Fh_dir_ino1,
+ Fh_dir_ino2,
+#else
+ Fh_ino1,
+ Fh_dir_ino1,
+#endif
+ Fh_igen,
+ Fh_h_type,
+ Fh_tail,
+
+ Fh_ino = Fh_ino1,
+ Fh_dir_ino = Fh_dir_ino1
+};
+
+static int au_test_anon(struct dentry *dentry)
+{
+ /* note: read d_flags without d_lock */
+ return !!(dentry->d_flags & DCACHE_DISCONNECTED);
+}
+
+/* ---------------------------------------------------------------------- */
+/* inode generation external table */
+
+void au_xigen_inc(struct inode *inode)
+{
+ loff_t pos;
+ ssize_t sz;
+ __u32 igen;
+ struct super_block *sb;
+ struct au_sbinfo *sbinfo;
+
+ sb = inode->i_sb;
+ AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
+
+ sbinfo = au_sbi(sb);
+ pos = inode->i_ino;
+ pos *= sizeof(igen);
+ igen = inode->i_generation + 1;
+ sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
+ sizeof(igen), &pos);
+ if (sz == sizeof(igen))
+ return; /* success */
+
+ if (unlikely(sz >= 0))
+ AuIOErr("xigen error (%zd)\n", sz);
+}
+
+int au_xigen_new(struct inode *inode)
+{
+ int err;
+ loff_t pos;
+ ssize_t sz;
+ struct super_block *sb;
+ struct au_sbinfo *sbinfo;
+ struct file *file;
+
+ err = 0;
+ /* todo: dirty, at mount time */
+ if (inode->i_ino == AUFS_ROOT_INO)
+ goto out;
+ sb = inode->i_sb;
+ SiMustAnyLock(sb);
+ if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
+ goto out;
+
+ err = -EFBIG;
+ pos = inode->i_ino;
+ if (unlikely(au_loff_max / sizeof(inode->i_generation) - 1 < pos)) {
+ AuIOErr1("too large i%lld\n", pos);
+ goto out;
+ }
+ pos *= sizeof(inode->i_generation);
+
+ err = 0;
+ sbinfo = au_sbi(sb);
+ file = sbinfo->si_xigen;
+ BUG_ON(!file);
+
+ if (i_size_read(file->f_dentry->d_inode)
+ < pos + sizeof(inode->i_generation)) {
+ inode->i_generation = atomic_inc_return(&sbinfo->si_xigen_next);
+ sz = xino_fwrite(sbinfo->si_xwrite, file, &inode->i_generation,
+ sizeof(inode->i_generation), &pos);
+ } else
+ sz = xino_fread(sbinfo->si_xread, file, &inode->i_generation,
+ sizeof(inode->i_generation), &pos);
+ if (sz == sizeof(inode->i_generation))
+ goto out; /* success */
+
+ err = sz;
+ if (unlikely(sz >= 0)) {
+ err = -EIO;
+ AuIOErr("xigen error (%zd)\n", sz);
+ }
+
+out:
+ return err;
+}
+
+int au_xigen_set(struct super_block *sb, struct file *base)
+{
+ int err;
+ struct au_sbinfo *sbinfo;
+ struct file *file;
+
+ SiMustWriteLock(sb);
+
+ sbinfo = au_sbi(sb);
+ file = au_xino_create2(base, sbinfo->si_xigen);
+ err = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out;
+ err = 0;
+ if (sbinfo->si_xigen)
+ fput(sbinfo->si_xigen);
+ sbinfo->si_xigen = file;
+
+out:
+ return err;
+}
+
+void au_xigen_clr(struct super_block *sb)
+{
+ struct au_sbinfo *sbinfo;
+
+ SiMustWriteLock(sb);
+
+ sbinfo = au_sbi(sb);
+ if (sbinfo->si_xigen) {
+ fput(sbinfo->si_xigen);
+ sbinfo->si_xigen = NULL;
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+static struct dentry *decode_by_ino(struct super_block *sb, ino_t ino,
+ ino_t dir_ino)
+{
+ struct dentry *dentry, *d;
+ struct inode *inode;
+ unsigned int sigen;
+
+ dentry = NULL;
+ inode = ilookup(sb, ino);
+ if (!inode)
+ goto out;
+
+ dentry = ERR_PTR(-ESTALE);
+ sigen = au_sigen(sb);
+ if (unlikely(is_bad_inode(inode)
+ || IS_DEADDIR(inode)
+ || sigen != au_iigen(inode)))
+ goto out_iput;
+
+ dentry = NULL;
+ if (!dir_ino || S_ISDIR(inode->i_mode))
+ dentry = d_find_alias(inode);
+ else {
+ spin_lock(&inode->i_lock);
+ list_for_each_entry(d, &inode->i_dentry, d_alias) {
+ spin_lock(&d->d_lock);
+ if (!au_test_anon(d)
+ && d->d_parent->d_inode->i_ino == dir_ino) {
+ dentry = dget_dlock(d);
+ spin_unlock(&d->d_lock);
+ break;
+ }
+ spin_unlock(&d->d_lock);
+ }
+ spin_unlock(&inode->i_lock);
+ }
+ if (unlikely(dentry && au_digen_test(dentry, sigen))) {
+ /* need to refresh */
+ dput(dentry);
+ dentry = NULL;
+ }
+
+out_iput:
+ iput(inode);
+out:
+ AuTraceErrPtr(dentry);
+ return dentry;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* todo: dirty? */
+/* if exportfs_decode_fh() passed vfsmount*, we could be happy */
+
+struct au_compare_mnt_args {
+ /* input */
+ struct super_block *sb;
+
+ /* output */
+ struct vfsmount *mnt;
+};
+
+static int au_compare_mnt(struct vfsmount *mnt, void *arg)
+{
+ struct au_compare_mnt_args *a = arg;
+
+ if (mnt->mnt_sb != a->sb)
+ return 0;
+ a->mnt = mntget(mnt);
+ return 1;
+}
+
+static struct vfsmount *au_mnt_get(struct super_block *sb)
+{
+ int err;
+ struct au_compare_mnt_args args = {
+ .sb = sb
+ };
+ struct mnt_namespace *ns;
+
+ br_read_lock(vfsmount_lock);
+ /* no get/put ?? */
+ AuDebugOn(!current->nsproxy);
+ ns = current->nsproxy->mnt_ns;
+ AuDebugOn(!ns);
+ err = iterate_mounts(au_compare_mnt, &args, ns->root);
+ br_read_unlock(vfsmount_lock);
+ AuDebugOn(!err);
+ AuDebugOn(!args.mnt);
+ return args.mnt;
+}
+
+struct au_nfsd_si_lock {
+ unsigned int sigen;
+ aufs_bindex_t bindex, br_id;
+ unsigned char force_lock;
+};
+
+static int si_nfsd_read_lock(struct super_block *sb,
+ struct au_nfsd_si_lock *nsi_lock)
+{
+ int err;
+ aufs_bindex_t bindex;
+
+ si_read_lock(sb, AuLock_FLUSH);
+
+ /* branch id may be wrapped around */
+ err = 0;
+ bindex = au_br_index(sb, nsi_lock->br_id);
+ if (bindex >= 0 && nsi_lock->sigen + AUFS_BRANCH_MAX > au_sigen(sb))
+ goto out; /* success */
+
+ err = -ESTALE;
+ bindex = -1;
+ if (!nsi_lock->force_lock)
+ si_read_unlock(sb);
+
+out:
+ nsi_lock->bindex = bindex;
+ return err;
+}
+
+struct find_name_by_ino {
+ int called, found;
+ ino_t ino;
+ char *name;
+ int namelen;
+};
+
+static int
+find_name_by_ino(void *arg, const char *name, int namelen, loff_t offset,
+ u64 ino, unsigned int d_type)
+{
+ struct find_name_by_ino *a = arg;
+
+ a->called++;
+ if (a->ino != ino)
+ return 0;
+
+ memcpy(a->name, name, namelen);
+ a->namelen = namelen;
+ a->found = 1;
+ return 1;
+}
+
+static struct dentry *au_lkup_by_ino(struct path *path, ino_t ino,
+ struct au_nfsd_si_lock *nsi_lock)
+{
+ struct dentry *dentry, *parent;
+ struct file *file;
+ struct inode *dir;
+ struct find_name_by_ino arg;
+ int err;
+
+ parent = path->dentry;
+ if (nsi_lock)
+ si_read_unlock(parent->d_sb);
+ file = vfsub_dentry_open(path, au_dir_roflags);
+ dentry = (void *)file;
+ if (IS_ERR(file))
+ goto out;
+
+ dentry = ERR_PTR(-ENOMEM);
+ arg.name = __getname_gfp(GFP_NOFS);
+ if (unlikely(!arg.name))
+ goto out_file;
+ arg.ino = ino;
+ arg.found = 0;
+ do {
+ arg.called = 0;
+ /* smp_mb(); */
+ err = vfsub_readdir(file, find_name_by_ino, &arg);
+ } while (!err && !arg.found && arg.called);
+ dentry = ERR_PTR(err);
+ if (unlikely(err))
+ goto out_name;
+ dentry = ERR_PTR(-ENOENT);
+ if (!arg.found)
+ goto out_name;
+
+ /* do not call au_lkup_one() */
+ dir = parent->d_inode;
+ mutex_lock(&dir->i_mutex);
+ dentry = vfsub_lookup_one_len(arg.name, parent, arg.namelen);
+ mutex_unlock(&dir->i_mutex);
+ AuTraceErrPtr(dentry);
+ if (IS_ERR(dentry))
+ goto out_name;
+ AuDebugOn(au_test_anon(dentry));
+ if (unlikely(!dentry->d_inode)) {
+ dput(dentry);
+ dentry = ERR_PTR(-ENOENT);
+ }
+
+out_name:
+ __putname(arg.name);
+out_file:
+ fput(file);
+out:
+ if (unlikely(nsi_lock
+ && si_nfsd_read_lock(parent->d_sb, nsi_lock) < 0))
+ if (!IS_ERR(dentry)) {
+ dput(dentry);
+ dentry = ERR_PTR(-ESTALE);
+ }
+ AuTraceErrPtr(dentry);
+ return dentry;
+}
+
+static struct dentry *decode_by_dir_ino(struct super_block *sb, ino_t ino,
+ ino_t dir_ino,
+ struct au_nfsd_si_lock *nsi_lock)
+{
+ struct dentry *dentry;
+ struct path path;
+
+ if (dir_ino != AUFS_ROOT_INO) {
+ path.dentry = decode_by_ino(sb, dir_ino, 0);
+ dentry = path.dentry;
+ if (!path.dentry || IS_ERR(path.dentry))
+ goto out;
+ AuDebugOn(au_test_anon(path.dentry));
+ } else
+ path.dentry = dget(sb->s_root);
+
+ path.mnt = au_mnt_get(sb);
+ dentry = au_lkup_by_ino(&path, ino, nsi_lock);
+ path_put(&path);
+
+out:
+ AuTraceErrPtr(dentry);
+ return dentry;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int h_acceptable(void *expv, struct dentry *dentry)
+{
+ return 1;
+}
+
+static char *au_build_path(struct dentry *h_parent, struct path *h_rootpath,
+ char *buf, int len, struct super_block *sb)
+{
+ char *p;
+ int n;
+ struct path path;
+
+ p = d_path(h_rootpath, buf, len);
+ if (IS_ERR(p))
+ goto out;
+ n = strlen(p);
+
+ path.mnt = h_rootpath->mnt;
+ path.dentry = h_parent;
+ p = d_path(&path, buf, len);
+ if (IS_ERR(p))
+ goto out;
+ if (n != 1)
+ p += n;
+
+ path.mnt = au_mnt_get(sb);
+ path.dentry = sb->s_root;
+ p = d_path(&path, buf, len - strlen(p));
+ mntput(path.mnt);
+ if (IS_ERR(p))
+ goto out;
+ if (n != 1)
+ p[strlen(p)] = '/';
+
+out:
+ AuTraceErrPtr(p);
+ return p;
+}
+
+static
+struct dentry *decode_by_path(struct super_block *sb, ino_t ino, __u32 *fh,
+ int fh_len, struct au_nfsd_si_lock *nsi_lock)
+{
+ struct dentry *dentry, *h_parent, *root;
+ struct super_block *h_sb;
+ char *pathname, *p;
+ struct vfsmount *h_mnt;
+ struct au_branch *br;
+ int err;
+ struct path path;
+
+ br = au_sbr(sb, nsi_lock->bindex);
+ h_mnt = br->br_mnt;
+ h_sb = h_mnt->mnt_sb;
+ /* todo: call lower fh_to_dentry()? fh_to_parent()? */
+ h_parent = exportfs_decode_fh(h_mnt, (void *)(fh + Fh_tail),
+ fh_len - Fh_tail, fh[Fh_h_type],
+ h_acceptable, /*context*/NULL);
+ dentry = h_parent;
+ if (unlikely(!h_parent || IS_ERR(h_parent))) {
+ AuWarn1("%s decode_fh failed, %ld\n",
+ au_sbtype(h_sb), PTR_ERR(h_parent));
+ goto out;
+ }
+ dentry = NULL;
+ if (unlikely(au_test_anon(h_parent))) {
+ AuWarn1("%s decode_fh returned a disconnected dentry\n",
+ au_sbtype(h_sb));
+ goto out_h_parent;
+ }
+
+ dentry = ERR_PTR(-ENOMEM);
+ pathname = (void *)__get_free_page(GFP_NOFS);
+ if (unlikely(!pathname))
+ goto out_h_parent;
+
+ root = sb->s_root;
+ path.mnt = h_mnt;
+ di_read_lock_parent(root, !AuLock_IR);
+ path.dentry = au_h_dptr(root, nsi_lock->bindex);
+ di_read_unlock(root, !AuLock_IR);
+ p = au_build_path(h_parent, &path, pathname, PAGE_SIZE, sb);
+ dentry = (void *)p;
+ if (IS_ERR(p))
+ goto out_pathname;
+
+ si_read_unlock(sb);
+ err = vfsub_kern_path(p, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
+ dentry = ERR_PTR(err);
+ if (unlikely(err))
+ goto out_relock;
+
+ dentry = ERR_PTR(-ENOENT);
+ AuDebugOn(au_test_anon(path.dentry));
+ if (unlikely(!path.dentry->d_inode))
+ goto out_path;
+
+ if (ino != path.dentry->d_inode->i_ino)
+ dentry = au_lkup_by_ino(&path, ino, /*nsi_lock*/NULL);
+ else
+ dentry = dget(path.dentry);
+
+out_path:
+ path_put(&path);
+out_relock:
+ if (unlikely(si_nfsd_read_lock(sb, nsi_lock) < 0))
+ if (!IS_ERR(dentry)) {
+ dput(dentry);
+ dentry = ERR_PTR(-ESTALE);
+ }
+out_pathname:
+ free_page((unsigned long)pathname);
+out_h_parent:
+ dput(h_parent);
+out:
+ AuTraceErrPtr(dentry);
+ return dentry;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static struct dentry *
+aufs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
+ int fh_type)
+{
+ struct dentry *dentry;
+ __u32 *fh = fid->raw;
+ struct au_branch *br;
+ ino_t ino, dir_ino;
+ struct au_nfsd_si_lock nsi_lock = {
+ .force_lock = 0
+ };
+
+ dentry = ERR_PTR(-ESTALE);
+ /* it should never happen, but the file handle is unreliable */
+ if (unlikely(fh_len < Fh_tail))
+ goto out;
+ nsi_lock.sigen = fh[Fh_sigen];
+ nsi_lock.br_id = fh[Fh_br_id];
+
+ /* branch id may be wrapped around */
+ br = NULL;
+ if (unlikely(si_nfsd_read_lock(sb, &nsi_lock)))
+ goto out;
+ nsi_lock.force_lock = 1;
+
+ /* is this inode still cached? */
+ ino = decode_ino(fh + Fh_ino);
+ /* it should never happen */
+ if (unlikely(ino == AUFS_ROOT_INO))
+ goto out;
+
+ dir_ino = decode_ino(fh + Fh_dir_ino);
+ dentry = decode_by_ino(sb, ino, dir_ino);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+ if (dentry)
+ goto accept;
+
+ /* is the parent dir cached? */
+ br = au_sbr(sb, nsi_lock.bindex);
+ atomic_inc(&br->br_count);
+ dentry = decode_by_dir_ino(sb, ino, dir_ino, &nsi_lock);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+ if (dentry)
+ goto accept;
+
+ /* lookup path */
+ dentry = decode_by_path(sb, ino, fh, fh_len, &nsi_lock);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+ if (unlikely(!dentry))
+ /* todo?: make it ESTALE */
+ goto out_unlock;
+
+accept:
+ if (!au_digen_test(dentry, au_sigen(sb))
+ && dentry->d_inode->i_generation == fh[Fh_igen])
+ goto out_unlock; /* success */
+
+ dput(dentry);
+ dentry = ERR_PTR(-ESTALE);
+out_unlock:
+ if (br)
+ atomic_dec(&br->br_count);
+ si_read_unlock(sb);
+out:
+ AuTraceErrPtr(dentry);
+ return dentry;
+}
+
+#if 0 /* reserved for future use */
+/* support subtreecheck option */
+static struct dentry *aufs_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct dentry *parent;
+ __u32 *fh = fid->raw;
+ ino_t dir_ino;
+
+ dir_ino = decode_ino(fh + Fh_dir_ino);
+ parent = decode_by_ino(sb, dir_ino, 0);
+ if (IS_ERR(parent))
+ goto out;
+ if (!parent)
+ parent = decode_by_path(sb, au_br_index(sb, fh[Fh_br_id]),
+ dir_ino, fh, fh_len);
+
+out:
+ AuTraceErrPtr(parent);
+ return parent;
+}
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+static int aufs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
+ int connectable)
+{
+ int err;
+ aufs_bindex_t bindex, bend;
+ struct super_block *sb, *h_sb;
+ struct inode *inode;
+ struct dentry *parent, *h_parent;
+ struct au_branch *br;
+
+ AuDebugOn(au_test_anon(dentry));
+
+ parent = NULL;
+ err = -ENOSPC;
+ if (unlikely(*max_len <= Fh_tail)) {
+ AuWarn1("NFSv2 client (max_len %d)?\n", *max_len);
+ goto out;
+ }
+
+ err = FILEID_ROOT;
+ if (IS_ROOT(dentry)) {
+ AuDebugOn(dentry->d_inode->i_ino != AUFS_ROOT_INO);
+ goto out;
+ }
+
+ h_parent = NULL;
+ err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_IR | AuLock_GEN);
+ if (unlikely(err))
+ goto out;
+
+ inode = dentry->d_inode;
+ AuDebugOn(!inode);
+ sb = dentry->d_sb;
+#ifdef CONFIG_AUFS_DEBUG
+ if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
+ AuWarn1("NFS-exporting requires xino\n");
+#endif
+ err = -EIO;
+ parent = dget_parent(dentry);
+ di_read_lock_parent(parent, !AuLock_IR);
+ bend = au_dbtaildir(parent);
+ for (bindex = au_dbstart(parent); bindex <= bend; bindex++) {
+ h_parent = au_h_dptr(parent, bindex);
+ if (h_parent) {
+ dget(h_parent);
+ break;
+ }
+ }
+ if (unlikely(!h_parent))
+ goto out_unlock;
+
+ err = -EPERM;
+ br = au_sbr(sb, bindex);
+ h_sb = br->br_mnt->mnt_sb;
+ if (unlikely(!h_sb->s_export_op)) {
+ AuErr1("%s branch is not exportable\n", au_sbtype(h_sb));
+ goto out_dput;
+ }
+
+ fh[Fh_br_id] = br->br_id;
+ fh[Fh_sigen] = au_sigen(sb);
+ encode_ino(fh + Fh_ino, inode->i_ino);
+ encode_ino(fh + Fh_dir_ino, parent->d_inode->i_ino);
+ fh[Fh_igen] = inode->i_generation;
+
+ *max_len -= Fh_tail;
+ fh[Fh_h_type] = exportfs_encode_fh(h_parent, (void *)(fh + Fh_tail),
+ max_len,
+ /*connectable or subtreecheck*/0);
+ err = fh[Fh_h_type];
+ *max_len += Fh_tail;
+ /* todo: macros? */
+ if (err != 255)
+ err = 99;
+ else
+ AuWarn1("%s encode_fh failed\n", au_sbtype(h_sb));
+
+out_dput:
+ dput(h_parent);
+out_unlock:
+ di_read_unlock(parent, !AuLock_IR);
+ dput(parent);
+ aufs_read_unlock(dentry, AuLock_IR);
+out:
+ if (unlikely(err < 0))
+ err = 255;
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int aufs_commit_metadata(struct inode *inode)
+{
+ int err;
+ aufs_bindex_t bindex;
+ struct super_block *sb;
+ struct inode *h_inode;
+ int (*f)(struct inode *inode);
+
+ sb = inode->i_sb;
+ si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
+ ii_write_lock_child(inode);
+ bindex = au_ibstart(inode);
+ AuDebugOn(bindex < 0);
+ h_inode = au_h_iptr(inode, bindex);
+
+ f = h_inode->i_sb->s_export_op->commit_metadata;
+ if (f)
+ err = f(h_inode);
+ else {
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 0 /* metadata only */
+ };
+
+ err = sync_inode(h_inode, &wbc);
+ }
+
+ au_cpup_attr_timesizes(inode);
+ ii_write_unlock(inode);
+ si_read_unlock(sb);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static struct export_operations aufs_export_op = {
+ .fh_to_dentry = aufs_fh_to_dentry,
+ /* .fh_to_parent = aufs_fh_to_parent, */
+ .encode_fh = aufs_encode_fh,
+ .commit_metadata = aufs_commit_metadata
+};
+
+void au_export_init(struct super_block *sb)
+{
+ struct au_sbinfo *sbinfo;
+ __u32 u;
+
+ sb->s_export_op = &aufs_export_op;
+ sbinfo = au_sbi(sb);
+ sbinfo->si_xigen = NULL;
+ get_random_bytes(&u, sizeof(u));
+ BUILD_BUG_ON(sizeof(u) != sizeof(int));
+ atomic_set(&sbinfo->si_xigen_next, u);
+}
git.openpandora.org / pandora-kernel.git / blobdiff