mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Dan Carpenter](/assets/img/avatar_default.png)
d_obtain_alias() doesn't return NULL, it returns an ERR_PTR(). Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Sage Weil <sage@newdream.net>
224 lines
5.4 KiB
C
224 lines
5.4 KiB
C
#include "ceph_debug.h"
|
|
|
|
#include <linux/exportfs.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/unaligned.h>
|
|
|
|
#include "super.h"
|
|
|
|
/*
|
|
* NFS export support
|
|
*
|
|
* NFS re-export of a ceph mount is, at present, only semireliable.
|
|
* The basic issue is that the Ceph architectures doesn't lend itself
|
|
* well to generating filehandles that will remain valid forever.
|
|
*
|
|
* So, we do our best. If you're lucky, your inode will be in the
|
|
* client's cache. If it's not, and you have a connectable fh, then
|
|
* the MDS server may be able to find it for you. Otherwise, you get
|
|
* ESTALE.
|
|
*
|
|
* There are ways to this more reliable, but in the non-connectable fh
|
|
* case, we won't every work perfectly, and in the connectable case,
|
|
* some changes are needed on the MDS side to work better.
|
|
*/
|
|
|
|
/*
|
|
* Basic fh
|
|
*/
|
|
struct ceph_nfs_fh {
|
|
u64 ino;
|
|
} __attribute__ ((packed));
|
|
|
|
/*
|
|
* Larger 'connectable' fh that includes parent ino and name hash.
|
|
* Use this whenever possible, as it works more reliably.
|
|
*/
|
|
struct ceph_nfs_confh {
|
|
u64 ino, parent_ino;
|
|
u32 parent_name_hash;
|
|
} __attribute__ ((packed));
|
|
|
|
static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
|
|
int connectable)
|
|
{
|
|
struct ceph_nfs_fh *fh = (void *)rawfh;
|
|
struct ceph_nfs_confh *cfh = (void *)rawfh;
|
|
struct dentry *parent = dentry->d_parent;
|
|
struct inode *inode = dentry->d_inode;
|
|
int type;
|
|
|
|
/* don't re-export snaps */
|
|
if (ceph_snap(inode) != CEPH_NOSNAP)
|
|
return -EINVAL;
|
|
|
|
if (*max_len >= sizeof(*cfh)) {
|
|
dout("encode_fh %p connectable\n", dentry);
|
|
cfh->ino = ceph_ino(dentry->d_inode);
|
|
cfh->parent_ino = ceph_ino(parent->d_inode);
|
|
cfh->parent_name_hash = parent->d_name.hash;
|
|
*max_len = sizeof(*cfh);
|
|
type = 2;
|
|
} else if (*max_len > sizeof(*fh)) {
|
|
if (connectable)
|
|
return -ENOSPC;
|
|
dout("encode_fh %p\n", dentry);
|
|
fh->ino = ceph_ino(dentry->d_inode);
|
|
*max_len = sizeof(*fh);
|
|
type = 1;
|
|
} else {
|
|
return -ENOSPC;
|
|
}
|
|
return type;
|
|
}
|
|
|
|
/*
|
|
* convert regular fh to dentry
|
|
*
|
|
* FIXME: we should try harder by querying the mds for the ino.
|
|
*/
|
|
static struct dentry *__fh_to_dentry(struct super_block *sb,
|
|
struct ceph_nfs_fh *fh)
|
|
{
|
|
struct inode *inode;
|
|
struct dentry *dentry;
|
|
struct ceph_vino vino;
|
|
int err;
|
|
|
|
dout("__fh_to_dentry %llx\n", fh->ino);
|
|
vino.ino = fh->ino;
|
|
vino.snap = CEPH_NOSNAP;
|
|
inode = ceph_find_inode(sb, vino);
|
|
if (!inode)
|
|
return ERR_PTR(-ESTALE);
|
|
|
|
dentry = d_obtain_alias(inode);
|
|
if (IS_ERR(dentry)) {
|
|
pr_err("fh_to_dentry %llx -- inode %p but ENOMEM\n",
|
|
fh->ino, inode);
|
|
iput(inode);
|
|
return dentry;
|
|
}
|
|
err = ceph_init_dentry(dentry);
|
|
|
|
if (err < 0) {
|
|
iput(inode);
|
|
return ERR_PTR(err);
|
|
}
|
|
dout("__fh_to_dentry %llx %p dentry %p\n", fh->ino, inode, dentry);
|
|
return dentry;
|
|
}
|
|
|
|
/*
|
|
* convert connectable fh to dentry
|
|
*/
|
|
static struct dentry *__cfh_to_dentry(struct super_block *sb,
|
|
struct ceph_nfs_confh *cfh)
|
|
{
|
|
struct ceph_mds_client *mdsc = &ceph_sb_to_client(sb)->mdsc;
|
|
struct inode *inode;
|
|
struct dentry *dentry;
|
|
struct ceph_vino vino;
|
|
int err;
|
|
|
|
dout("__cfh_to_dentry %llx (%llx/%x)\n",
|
|
cfh->ino, cfh->parent_ino, cfh->parent_name_hash);
|
|
|
|
vino.ino = cfh->ino;
|
|
vino.snap = CEPH_NOSNAP;
|
|
inode = ceph_find_inode(sb, vino);
|
|
if (!inode) {
|
|
struct ceph_mds_request *req;
|
|
|
|
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPHASH,
|
|
USE_ANY_MDS);
|
|
if (IS_ERR(req))
|
|
return ERR_PTR(PTR_ERR(req));
|
|
|
|
req->r_ino1 = vino;
|
|
req->r_ino2.ino = cfh->parent_ino;
|
|
req->r_ino2.snap = CEPH_NOSNAP;
|
|
req->r_path2 = kmalloc(16, GFP_NOFS);
|
|
snprintf(req->r_path2, 16, "%d", cfh->parent_name_hash);
|
|
req->r_num_caps = 1;
|
|
err = ceph_mdsc_do_request(mdsc, NULL, req);
|
|
ceph_mdsc_put_request(req);
|
|
inode = ceph_find_inode(sb, vino);
|
|
if (!inode)
|
|
return ERR_PTR(err ? err : -ESTALE);
|
|
}
|
|
|
|
dentry = d_obtain_alias(inode);
|
|
if (IS_ERR(dentry)) {
|
|
pr_err("cfh_to_dentry %llx -- inode %p but ENOMEM\n",
|
|
cfh->ino, inode);
|
|
iput(inode);
|
|
return dentry;
|
|
}
|
|
err = ceph_init_dentry(dentry);
|
|
if (err < 0) {
|
|
iput(inode);
|
|
return ERR_PTR(err);
|
|
}
|
|
dout("__cfh_to_dentry %llx %p dentry %p\n", cfh->ino, inode, dentry);
|
|
return dentry;
|
|
}
|
|
|
|
static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid,
|
|
int fh_len, int fh_type)
|
|
{
|
|
if (fh_type == 1)
|
|
return __fh_to_dentry(sb, (struct ceph_nfs_fh *)fid->raw);
|
|
else
|
|
return __cfh_to_dentry(sb, (struct ceph_nfs_confh *)fid->raw);
|
|
}
|
|
|
|
/*
|
|
* get parent, if possible.
|
|
*
|
|
* FIXME: we could do better by querying the mds to discover the
|
|
* parent.
|
|
*/
|
|
static struct dentry *ceph_fh_to_parent(struct super_block *sb,
|
|
struct fid *fid,
|
|
int fh_len, int fh_type)
|
|
{
|
|
struct ceph_nfs_confh *cfh = (void *)fid->raw;
|
|
struct ceph_vino vino;
|
|
struct inode *inode;
|
|
struct dentry *dentry;
|
|
int err;
|
|
|
|
if (fh_type == 1)
|
|
return ERR_PTR(-ESTALE);
|
|
|
|
pr_debug("fh_to_parent %llx/%d\n", cfh->parent_ino,
|
|
cfh->parent_name_hash);
|
|
|
|
vino.ino = cfh->ino;
|
|
vino.snap = CEPH_NOSNAP;
|
|
inode = ceph_find_inode(sb, vino);
|
|
if (!inode)
|
|
return ERR_PTR(-ESTALE);
|
|
|
|
dentry = d_obtain_alias(inode);
|
|
if (IS_ERR(dentry)) {
|
|
pr_err("fh_to_parent %llx -- inode %p but ENOMEM\n",
|
|
cfh->ino, inode);
|
|
iput(inode);
|
|
return dentry;
|
|
}
|
|
err = ceph_init_dentry(dentry);
|
|
if (err < 0) {
|
|
iput(inode);
|
|
return ERR_PTR(err);
|
|
}
|
|
dout("fh_to_parent %llx %p dentry %p\n", cfh->ino, inode, dentry);
|
|
return dentry;
|
|
}
|
|
|
|
const struct export_operations ceph_export_ops = {
|
|
.encode_fh = ceph_encode_fh,
|
|
.fh_to_dentry = ceph_fh_to_dentry,
|
|
.fh_to_parent = ceph_fh_to_parent,
|
|
};
|