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;
ino_t ino, dir_ino;
aufs_bindex_t bindex;
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 */
bindex = si_nfsd_read_lock(sb, &nsi_lock);
if (unlikely(bindex < 0))
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? */
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, bindex, 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 (dentry->d_inode->i_generation == fh[Fh_igen])
goto out_unlock; /* success */
dput(dentry);
dentry = ERR_PTR(-ESTALE);
out_unlock:
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;
}
err = -EIO;
h_parent = NULL;
sb = dentry->d_sb;
aufs_read_lock(dentry, AuLock_FLUSH | AuLock_IR);
parent = dget_parent(dentry);
di_read_lock_parent(parent, !AuLock_IR);
inode = dentry->d_inode;
AuDebugOn(!inode);
#ifdef CONFIG_AUFS_DEBUG
if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
AuWarn1("NFS-exporting requires xino\n");
#endif
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
struct dentry *decode_by_path(struct super_block *sb, aufs_bindex_t bindex,
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, bindex);
/* au_br_get(br); */
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, 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:
/* au_br_put(br); */
AuTraceErrPtr(dentry);
return dentry;
}
static struct dentry *
aufs_decode_fh(struct super_block *sb, __u32 *fh, int fh_len, int fh_type,
int (*acceptable)(void *context, struct dentry *de),
void *context)
{
struct dentry *dentry;
ino_t ino, dir_ino;
aufs_bindex_t bindex;
struct au_nfsd_si_lock nsi_lock = {
.sigen = fh[Fh_sigen],
.br_id = fh[Fh_br_id],
.force_lock = 0
};
LKTRTrace("%d, fh{br_id %u, sigen %u, i%u, diri%u, g%u}\n",
fh_type, fh[Fh_br_id], fh[Fh_sigen], fh[Fh_ino],
fh[Fh_dir_ino], fh[Fh_igen]);
AuDebugOn(fh_len < Fh_tail);
dentry = ERR_PTR(-ESTALE);
/* branch id may be wrapped around */
bindex = si_nfsd_read_lock(sb, &nsi_lock);
if (unlikely(bindex < 0))
goto out;
nsi_lock.force_lock = 1;
/* is this inode still cached? */
ino = decode_ino(fh + Fh_ino);
AuDebugOn(ino == AUFS_ROOT_INO);
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? */
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, bindex, ino, fh, fh_len, &nsi_lock);
if (IS_ERR(dentry))
goto out_unlock;
if (unlikely(!dentry))
goto out_unlock;
accept:
LKTRLabel(accept);
if (dentry->d_inode->i_generation == fh[Fh_igen]
&& acceptable(context, dentry))
goto out_unlock; /* success */
LKTRLabel(stale);
dput(dentry);
dentry = ERR_PTR(-ESTALE);
out_unlock:
LKTRLabel(out_unlock);
si_read_unlock(sb);
out:
LKTRLabel(out);
if (0 && IS_ERR(dentry))
dentry = ERR_PTR(-ESTALE);
AuTraceErrPtr(dentry);
return dentry;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
static struct dentry *
aufs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
int fh_type)
{
return aufs_decode_fh(sb, fid->raw, fh_len, fh_type, h_acceptable,
/*context*/NULL);
}
#endif /* KERNEL_VERSION */
/* ---------------------------------------------------------------------- */
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;
LKTRTrace("%.*s, max %d, conn %d\n",
AuDLNPair(dentry), *max_len, connectable);
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 = 0; //FILEID_ROOT;
if (IS_ROOT(dentry)) {
AuDebugOn(dentry->d_inode->i_ino != AUFS_ROOT_INO);
goto out;
}
err = -EIO;
h_parent = NULL;
sb = dentry->d_sb;
aufs_read_lock(dentry, AuLock_FLUSH | AuLock_IR);
parent = dget_parent(dentry);
di_read_lock_parent(parent, !AuLock_IR);
inode = dentry->d_inode;
AuDebugOn(!inode);
#ifdef CONFIG_AUFS_DEBUG
{
unsigned int mnt_flags = au_mntflags(sb);
if (unlikely(!au_opt_test_xino(mnt_flags)))
AuWarn1("NFS-exporting requires xino\n");
if (unlikely(0 && !au_opt_test(mnt_flags, UDBA_INOTIFY)))
AuWarn1("udba=inotify is recommended "
"for NFS-exporting\n");
}
#endif
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;
LKTRTrace("b%d\n", bindex);
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;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
/* it should be set at exporting time */
if (unlikely(!h_sb->s_export_op->find_exported_dentry)) {
AuWarn("set default find_exported_dentry for %s\n",
au_sbtype(h_sb));
h_sb->s_export_op->find_exported_dentry = find_exported_dentry;
}
#endif
*max_len -= Fh_tail;
fh[Fh_h_type] = au_call_encode_fh(h_parent, 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:
AuTraceErr(err);
if (unlikely(err < 0))
err = 255;
return err;
}
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 *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;
LKTRTrace("%.*s, i%lu\n", AuDLNPair(parent), (unsigned long)ino);
if (nsi_lock)
si_read_unlock(parent->d_sb);
path_get(path);
file = dentry_open(parent, path->mnt, au_dir_roflags);
dentry = (void *)file;
if (IS_ERR(file))
goto out;
dentry = ERR_PTR(-ENOMEM);
arg.name = __getname();
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, /*dlgt*/0);
} 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(), nor dlgt */
dir = parent->d_inode;
vfsub_i_lock(dir);
dentry = vfsub_lookup_one_len(arg.name, parent, arg.namelen);
vfsub_i_unlock(dir);
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;
}