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mvfs_linux_sops.c
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mvfs_linux_sops.c
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/*
* Copyright (C) 1999, 2014 IBM Corporation.
*
* This program 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, 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
*
* Author: IBM Corporation
* This module is part of the IBM (R) Rational (R) ClearCase (R)
* Multi-version file system (MVFS).
* For support, please visit http://www.ibm.com/software/support
*/
/*
* superblock operations (plus some utilities) for MVFS
*/
#include "vnode_linux.h"
#include "mvfs_linux_shadow.h"
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,38)
/* for noop_backing_dev_info */
#include <linux/backing-dev.h>
#endif
void
vnlayer_put_super(SUPER_T *super_p);
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0)
void
vnlayer_write_super(SUPER_T *super_p);
#else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0) */
int
vnlayer_sync_super(
struct super_block *super_p,
int wait
);
#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0) */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) && !defined(SLES10SP2)
int
vnlayer_linux_statfs(
SUPER_T *super_p,
LINUX_STATFS_T *stat_p
);
#else
int
vnlayer_linux_statfs(
DENT_T *dent_p,
LINUX_STATFS_T *stat_p
);
#endif
int
vnlayer_remount_fs(
SUPER_T *super_p,
int *flags,
char *data
);
void
mvfs_clear_inode(
INODE_T *inode_p
);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
void
mvfs_evict_inode(struct inode *inode_p);
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) || \
LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
void
mvfs_linux_umount_begin(SUPER_T *super_p);
#else
void
mvfs_linux_umount_begin(
struct vfsmount *mnt,
int flags);
#endif
int
vnlayer_fill_super(
SUPER_T *super_p,
void *data_p,
int silent
);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
int
vnlayer_inode_to_fh(
struct inode *inode,
__u32 *fh,
int *lenp,
struct inode *parent
);
#else
int
vnlayer_dentry_to_fh(
struct dentry *dent,
__u32 *fh,
int *lenp,
int need_parent
);
#endif
struct dentry *
vnlayer_get_dentry(
SUPER_T *sb,
void *fhbits
);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
struct dentry *
vnlayer_decode_fh(
SUPER_T *sb,
__u32 *fh,
int len, /* counted in units of 4-bytes */
int fhtype,
int (*acceptable)(void *context, struct dentry *de),
void *context
);
#else /* LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24) */
struct dentry * vnlayer_fh_to_dentry(
SUPER_T *sb,
struct fid *fh,
int len, /* counted in units of 4-bytes */
int fhtype
);
struct dentry * vnlayer_fh_to_parent(
SUPER_T *sb,
struct fid *fh,
int len, /* counted in units of 4-bytes */
int fhtype
);
#endif /* else LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24) */
struct dentry *
vnlayer_get_parent(struct dentry *child);
static struct export_operations vnlayer_export_ops = {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
.encode_fh = &vnlayer_inode_to_fh,
#else
.encode_fh = &vnlayer_dentry_to_fh,
#endif
.get_parent = &vnlayer_get_parent,
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,24)
.decode_fh = &vnlayer_decode_fh,
.get_dentry = &vnlayer_get_dentry,
#else
.fh_to_dentry = vnlayer_fh_to_dentry,
.fh_to_parent = vnlayer_fh_to_parent,
#endif
};
# if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
SUPER_T *
vnlayer_get_sb(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *raw_data
);
#elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
int
vnlayer_get_sb(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *raw_data,
struct vfsmount *mnt
);
#else
struct dentry *
vnlayer_mount(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *data
);
#endif
void
vnlayer_kill_sb(SUPER_T *sbp);
INODE_T *
vnlayer_alloc_inode(SUPER_T *sbp);
void
vnlayer_destroy_inode(INODE_T *inode);
STATIC struct dentry *
vnlayer_find_dentry(VNODE_T *vp);
SB_OPS_T mvfs_super_ops = {
/* no read_inode */
/* no write_inode */
/* No put_inode. The work is done now in clear_inode */
/* no delete_inode (even before 2.6.36) */
.put_super = &vnlayer_put_super,
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0)
.write_super = &vnlayer_write_super,
#else
.sync_fs = &vnlayer_sync_super,
#endif
.statfs = &vnlayer_linux_statfs,
.remount_fs = &vnlayer_remount_fs,
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
.clear_inode = &mvfs_clear_inode,
#else
.evict_inode = mvfs_evict_inode,
#endif
/* inodes no longer have space for fs data (e.g. our vnode). */
.alloc_inode = &vnlayer_alloc_inode,
.destroy_inode = &vnlayer_destroy_inode,
.umount_begin = &mvfs_linux_umount_begin,
};
/* Define the filesytem type for loading
* Note that the flag is set to require a device for loading. Our
* module initialization routine will register /dev/mvfs for us to
* use. This is done so that we can control our own minor numbers.
*/
struct file_system_type mvfs_file_system =
{
.name = "mvfs",
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,9,0)
/* weak_revalidate is not implemented */
.fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
#else
.fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_REVAL_DOT,
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
.get_sb = &vnlayer_get_sb,
#else
.mount = vnlayer_mount,
#endif
.kill_sb = &vnlayer_kill_sb,
.owner = THIS_MODULE,
};
void
vnlayer_put_super(struct super_block *super_p)
{
int err;
CALL_DATA_T cd;
ASSERT_KERNEL_LOCKED();
ASSERT_SB_LOCKED(super_p);
mdki_linux_init_call_data(&cd);
err = VFS_UNMOUNT(SBTOVFS(super_p), &cd);
mdki_linux_destroy_call_data(&cd);
if (err != 0) {
VFS_LOG(SBTOVFS(super_p), VFS_LOG_ERR,
"Linux file system interface doesn't let vnode/vfs reject unmounts: error %d\n", err);
}
return /* mdki_errno_unix_to_linux(err)*/;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0)
void
vnlayer_write_super(struct super_block *super_p)
{
CALL_DATA_T cd;
int err;
ASSERT_SB_LOCKED(super_p);
mdki_linux_init_call_data(&cd);
err = VFS_SYNC(SBTOVFS(super_p), SBTOVFS(super_p), 0, &cd);
mdki_linux_destroy_call_data(&cd);
/* They rewrote sync_supers so that it won't proceed through their loop
* until the dirty bit is cleared.
*/
super_p->s_dirt = 0;
if (err != 0)
VFS_LOG(SBTOVFS(super_p), VFS_LOG_ERR, "%s: error %d syncing\n",
__func__, err);
return /* mdki_errno_unix_to_linux(err) */;
}
#else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0) */
int
vnlayer_sync_super(
struct super_block *super_p,
int wait
)
{
CALL_DATA_T cd;
int err;
/* if wait is not allowed, do nothing */
if (wait == 0) {
return 0;
}
ASSERT_SB_LOCKED(super_p);
mdki_linux_init_call_data(&cd);
err = VFS_SYNC(SBTOVFS(super_p), SBTOVFS(super_p), 0, &cd);
mdki_linux_destroy_call_data(&cd);
if (err != 0) {
VFS_LOG(SBTOVFS(super_p), VFS_LOG_ERR, "%s: error %d syncing\n",
__func__, err);
}
return mdki_errno_unix_to_linux(err);
}
#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0) */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) && !defined(SLES10SP2)
int
vnlayer_linux_statfs(
SUPER_T *super_p,
LINUX_STATFS_T *stat_p
)
#else
int
vnlayer_linux_statfs(
DENT_T *dent_p,
LINUX_STATFS_T *stat_p
)
#endif
{
int error;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) && !defined(SLES10SP2)
error = VFS_STATVFS(SBTOVFS(super_p), stat_p);
#else
error = VFS_STATVFS(SBTOVFS(dent_p->d_sb), stat_p);
#endif
return (-error);
}
int
vnlayer_remount_fs(
struct super_block *super_p,
int *flags,
char *data
)
{
VFS_T *vfsp = SBTOVFS(super_p);
VFS_LOG(vfsp, VFS_LOG_ERR,
"Vnode/VFS does not support remounting of file systems (sb=%p)\n",
super_p);
return -EINVAL;
}
void
mvfs_clear_inode(struct inode *inode_p)
{
CALL_DATA_T cd;
ASSERT(MDKI_INOISOURS(inode_p));
if (MDKI_INOISMVFS(inode_p)) {
/* If we're an mnode-base vnode, do all this stuff ... */
VNODE_T *vp = ITOV(inode_p);
int error;
ASSERT(I_COUNT(inode_p) == 0);
ASSERT(inode_p->i_state & I_FREEING);
mdki_linux_init_call_data(&cd);
/*
* Do actual deactivation of the vnode/mnode
*/
error = VOP_INACTIVE(vp, &cd);
mdki_linux_destroy_call_data(&cd);
if (error)
MDKI_VFS_LOG(VFS_LOG_ERR, "mvfs_clear_inode: inactive error %d\n",
error);
} else if (MDKI_INOISCLRVN(inode_p)) {
/* cleartext vnode */
vnlayer_linux_free_clrvnode(ITOV(inode_p));
} else {
MDKI_TRACE(TRACE_INACTIVE,"no work: inode_p=%p vp=%p cnt=%d\n", inode_p,
ITOV(inode_p), I_COUNT(inode_p));
}
MDKI_TRACE(TRACE_INACTIVE,"inode_p=%p vp=%p cnt=%d\n", inode_p,
ITOV(inode_p), I_COUNT(inode_p));
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
void
mvfs_evict_inode(struct inode *inode_p)
{
mvfs_clear_inode(inode_p);
truncate_inode_pages(&inode_p->i_data, 0);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
clear_inode(inode_p);
#else
end_writeback(inode_p);
#endif
}
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
# define MDKI_READ_MNT_COUNT(mnt) atomic_read(&(mnt)->mnt_count);
#elif LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
# include <linux/lglock.h>
DECLARE_LGLOCK(vfsmount_lock);
# ifdef CONFIG_SMP
# define MDKI_READ_MNT_COUNT(mnt) ({\
int cpu;\
int count = 0;\
br_read_lock(vfsmount_lock);\
for_each_possible_cpu(cpu) {\
count += per_cpu_ptr((mnt)->mnt_pcp, cpu)->mnt_count;\
}\
br_read_unlock(vfsmount_lock);\
count;})
# else /* CONFIG_SMP */
# define MDKI_READ_MNT_COUNT(mnt) ((mnt)->mnt_count)
# endif /* else CONFIG_SMP */
#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0) */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) || \
LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
extern void
mvfs_linux_umount_begin(SUPER_T *super_p)
#else
extern void
mvfs_linux_umount_begin(
struct vfsmount * mnt,
int flags
)
#endif
{
VNODE_T *vp;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) || \
LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
struct vfsmount *mnt;
#else
/*
* Since 2.6.18 and before 2.6.27 we have mnt as a parameter.
* But we still need super_p.
*/
SUPER_T *super_p = mnt->mnt_sb;
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
int mount_count = 0;
#endif
ASSERT(super_p != NULL);
ASSERT(super_p->s_root != NULL);
vp = ITOV(super_p->s_root->d_inode);
ASSERT(vp != NULL);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18) || \
LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
mnt = VTOVFSMNT(vp);
#else
/* Check that the mountpoint passed in matches the one
* from the vp that we are going to clear. Skip it otherwise.
* We know from experience that this can happen when unmounting
* loopback (bind) mounts.
*/
if (mnt != VTOVFSMNT(vp))
return;
#endif
/* Note that there is no mechanism for restoring the mount pointer
* in the vnode if an error happens later on in the umount. This is
* the only callback into the mvfs during umount. So far this has not
* been a problem and if we don't do this here, the umount will never
* succeed because the Linux code expects the mnt_count to be 2.
* The count is 3 at this point from the initial allocation of the
* vfsmnt structure, the path_lookup call in this umount call and
* from when we placed the pointer in the vp.
*/
if (mnt == NULL) {
MDKI_VFS_LOG(VFS_LOG_ERR, "%s: mnt is NULL\n", __FUNCTION__);
return;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
mount_count = MDKI_READ_MNT_COUNT(mnt);
if (mount_count == 3) {
MDKI_MNTPUT(mnt);
SET_VTOVFSMNT(vp, NULL);
}
#else
/*
* may_umount returns !0 when the ref counter is 2 (and other conditions).
* We took an extra ref, I'll drop it to test may_umount. If it is not
* ready to be unmounted, the put is reverted.
*/
MDKI_MNTPUT(mnt);
if (may_umount(mnt)) {
SET_VTOVFSMNT(vp, NULL);
} else {
/* not ready yet */
MDKI_MNTGET(mnt);
}
#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0) */
}
/* vnlayer_linux_mount
* This is a wrapper function to take the data passed in by the linux
* mount and massage it into a form that is usable by our common routines
*
* IN SUPER_T *super_p
* void *data_p
*
*/
extern int
vnlayer_linux_mount(
VFS_T *vfsp,
void *data_p
)
{
int err;
CALL_DATA_T cd;
MVFS_CALLER_INFO_STRUCT ctx;
mdki_linux_init_call_data(&cd);
BZERO(&ctx, sizeof(ctx));
/* VFS_MOUNT method must detect 32- or 64-bit caller, if necessary */
err = VFS_MOUNT(vfsp, NULL, NULL, vfsp->vfs_flag,
data_p, 0, &cd, &ctx);
err = mdki_errno_unix_to_linux(err);
mdki_linux_destroy_call_data(&cd);
return(err);
}
int
vnlayer_fill_super(
SUPER_T *super_p,
void *data_p,
int silent
)
{
INODE_T *ino_p;
VNODE_T *rootvp;
VATTR_T va;
VFS_T *vfsp;
int err = 0;
CALL_DATA_T cd;
ASSERT_KERNEL_LOCKED(); /* sys_mount() */
ASSERT_SB_MOUNT_LOCKED_W(super_p);
/* can't assert on mount_sem, we don't have access to it. */
if (vnlayer_vfs_opvec == NULL) {
MDKI_VFS_LOG(VFS_LOG_ERR,
"%s: VFS operation not set yet "
"(no file system module loaded?)\n", __func__);
err = -ENODATA;
goto return_NULL;
}
if (MDKI_INOISOURS(vnlayer_get_urdir_inode())) {
/* can't handle this case */
MDKI_VFS_LOG(VFS_LOG_ERR,
"%s: can't handle mounts inside setview.\n", __func__);
err = -EINVAL;
goto return_NULL;
}
/*
* The only fields we have coming in are s_type and s_flags.
*/
/* Verify this */
super_p->s_blocksize = MVFS_DEF_BLKSIZE;
super_p->s_blocksize_bits = MVFS_DEF_BLKSIZE_BITS;
super_p->s_maxbytes = MVFS_DEF_MAX_FILESIZE;
super_p->s_op = &mvfs_super_ops;
super_p->s_export_op = &vnlayer_export_ops;
super_p->dq_op = NULL;
super_p->s_magic = MVFS_SUPER_MAGIC;
/*
* XXX This module is currently restricted to one client file system
* type at a time, as registered via the vnlayer_vfs_opvec.
*/
vfsp = KMEM_ALLOC(sizeof(*vfsp), KM_SLEEP);
if (vfsp == NULL) {
MDKI_VFS_LOG(VFS_LOG_ERR, "%s failed: no memory\n", __func__);
SET_SBTOVFS(super_p, NULL);
err = -ENOMEM;
goto return_NULL;
}
BZERO(vfsp, sizeof(*vfsp));
SET_VFSTOSB(vfsp, super_p);
SET_SBTOVFS(super_p, vfsp);
vfsp->vfs_op = vnlayer_vfs_opvec;
/* XXX fill in more of vfsp (flag?) */
if (super_p->s_flags & MS_RDONLY)
vfsp->vfs_flag |= VFS_RDONLY;
if (super_p->s_flags & MS_NOSUID)
vfsp->vfs_flag |= VFS_NOSUID;
err = vnlayer_linux_mount(vfsp, data_p);
if (err) {
goto bailout;
}
/*
* Now create our dentry and set that up in the superblock. Get
* the inode from the vnode at the root of the file system, and
* attach it to a new dentry.
*/
mdki_linux_init_call_data(&cd);
err = VFS_ROOT(SBTOVFS(super_p), &rootvp);
if (err) {
err = mdki_errno_unix_to_linux(err);
(void) VFS_UNMOUNT(vfsp,&cd);
mdki_linux_destroy_call_data(&cd);
goto bailout;
}
ino_p = VTOI(rootvp);
#ifdef CONFIG_FS_POSIX_ACL
/* If the system supports ACLs, we set the flag in the superblock
* depending on the ability of the underlying filesystem
*/
if (vfsp->vfs_flag & VFS_POSIXACL) {
super_p->s_flags |= MS_POSIXACL;
}
#endif
/*
* Call getattr() to prime this inode with real attributes via the
* callback to mdki_linux_vattr_pullup()
*/
VATTR_NULL(&va);
/* ignore error code, we're committed */
(void) VOP_GETATTR(rootvp, &va, 0, &cd);
/* This will allocate a dentry with a name of /, which is
* what Linux uses in all filesystem roots. The dentry is
* also not put on the hash chains because Linux does not
* hash file system roots. It finds them through the super
* blocks.
*/
super_p->s_root = VNODE_D_ALLOC_ROOT(ino_p);
if (super_p->s_root) {
if (VFSTOSB(vnlayer_looproot_vp->v_vfsp) == super_p) {
/* loopback names are done with regular dentry ops */
MDKI_SET_DOPS(super_p->s_root, &vnode_dentry_ops);
} else {
/*
* setview names come in via VOB mounts, they're marked
* with setview dentry ops
*/
MDKI_SET_DOPS(super_p->s_root, &vnode_setview_dentry_ops);
}
super_p->s_root->d_fsdata = NULL;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
atomic_set(&super_p->s_root->d_count, 1);
#endif
/* d_alloc_root assumes that the caller will take care of
* bumping the inode count for the dentry. So we will oblige
*/
igrab(ino_p);
} else {
VN_RELE(rootvp);
(void) VFS_UNMOUNT(vfsp,&cd);
mdki_linux_destroy_call_data(&cd);
err = -ENOMEM;
goto bailout;
}
mdki_linux_destroy_call_data(&cd);
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0)
super_p->s_dirt = 1; /* we want to be called on
write_super/sync() */
#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,6,0) */
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,38)
/* write back is delegated to the undelying fs */
super_p->s_bdi = &noop_backing_dev_info;
#endif
/*
* release reference on rootvp--super block holds appropriate
* references now
*/
VN_RELE(rootvp);
return(0);
bailout:
MDKI_VFS_LOG(VFS_LOG_ERR,
"%s failed: error %d\n", __func__,
vnlayer_errno_linux_to_unix(err));
SET_SBTOVFS(super_p, NULL);
KMEM_FREE(vfsp, sizeof(*vfsp));
return_NULL:
return(err);
}
/* This function is a callback from sget. We will setup the device number
* to be our default major and minor = 0. We will set the real device number
* later in vnlayer_fill_super when it calls into the mvfs proper. The
* reason for not just making this the call to fill_super is that we are
* called with the sb_lock spinlock held so we can't pend and vnlayer_fill_super
* allocates memory.
*/
int vnlayer_set_sb(
struct super_block *sb,
void *data
)
{
sb->s_dev = MKDEV(mvfs_major, 0);
return 0;
}
/* The regular block device interface would try to obtain partition information
* for the block device in question. The mvfs registers a block device
* merely to establish a set of major device numbers. We have no physical
* device and no partitions so the get_sb_bdev() interface does not work
* for us. Get_sb_nodev() explicitly uses major device 0 so that is not
* an option for us. Instead we use the sget() interface which gives us the
* ability to get a superblock and handle the device issues ourselves while the
* kernel handles getting it placed on the appropriate lists.
*
* Since 2.6.18 they added vfsmount to the parameters and changed the
* return type to int, but then since 2.6.39 the .get_sb callback was replaced
* by .mount and the interface changed substantially. So, for the sake of
* clarity, the function has been rewritten.
*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
SUPER_T *
vnlayer_get_sb(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *raw_data
)
#else
int
vnlayer_get_sb(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *raw_data,
struct vfsmount *mnt
)
#endif
{
SUPER_T *sb;
int err;
sb = sget(fs_type, NULL, vnlayer_set_sb, raw_data);
if (IS_ERR(sb)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
return sb;
#else
return PTR_ERR(sb);
#endif
}
err = vnlayer_fill_super(sb, raw_data, 0);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
if (err != 0) {
generic_shutdown_super(sb);
sb = ERR_PTR(err);
}
return sb;
#else
if (err != 0) {
generic_shutdown_super(sb);
}
else {
/* We need to fill the mnt struct */
simple_set_mnt(mnt, sb);
}
return err;
#endif
}
#else
struct dentry *
vnlayer_mount(
struct file_system_type *fs_type,
int flags,
const char *dev_name,
void *data
)
{
SUPER_T *sb;
int err;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0)
sb = sget(fs_type, NULL, vnlayer_set_sb, flags, data);
#else
sb = sget(fs_type, NULL, vnlayer_set_sb, data);
#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0) */
if (IS_ERR(sb)) {
return (struct dentry *)(sb);
}
sb->s_flags = flags;
if (sb->s_root == NULL) {
err = vnlayer_fill_super(sb, data, 0);
if (err != 0) {
deactivate_locked_super(sb);
return ERR_PTR(err);
}
sb->s_flags |= MS_ACTIVE;
}
/* return a dget dentry */
return dget(sb->s_root);
}
#endif
/* generic_shutdown_super() will call our put_super function which
* will handle all of our specific cleanup.
*/
void
vnlayer_kill_sb(SUPER_T *sbp)
{
generic_shutdown_super(sbp);
}
INODE_T *
vnlayer_alloc_inode(SUPER_T *sbp)
{
vnlayer_vnode_t *vnlvp;
vnlvp = (vnlayer_vnode_t *)kmem_cache_alloc(vnlayer_vnode_cache, GFP_KERNEL);
if (vnlvp != NULL) {
/* The inode used to be initialized by the kernel slab allocator
** because we used it to allocate an inode directly (see init_once() in
** fs/inode.c). However, now we allocate our vnode with an inode
** inside of it so we have to do the initialization ourselves.
**
** The caller must fully initialize the associated vnode.
*/
inode_init_once(&vnlvp->vnl_inode);
return(&vnlvp->vnl_inode);
} else {
return(NULL);
}
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,38)
static void
vnlayer_destroy_inode_callback(struct rcu_head *head)
{
struct inode *inode_p = container_of(head, struct inode, i_rcu);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0)
INIT_HLIST_HEAD(&inode_p->i_dentry);
#else
INIT_LIST_HEAD(&inode_p->i_dentry);
#endif
ASSERT(I_COUNT(inode_p) == 0);
ASSERT(inode_p->i_state & I_FREEING);
kmem_cache_free(vnlayer_vnode_cache, (vnlayer_vnode_t *) ITOV(inode_p));
}
#endif
void
vnlayer_destroy_inode(INODE_T *inode)
{
ASSERT(I_COUNT(inode) == 0);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
kmem_cache_free(vnlayer_vnode_cache, (vnlayer_vnode_t *)ITOV(inode));
#else
call_rcu(&inode->i_rcu, vnlayer_destroy_inode_callback);
#endif
}
#ifndef roundup
#define roundup(val, upto) (( ((val) + (upto) - 1) / (upto)) * (upto))
#endif
/*
* NFS access to vnode file systems.
*
* We provide dentry/inode_to_fh() and fh_to_dentry() methods so that the
* vnode-based file system can hook up its VOP_FID() and VFS_VGET()
* methods. The Linux NFS server calls these methods when encoding an
* object into a file handle to be passed to the client for future
* use, and when decoding a file handle and looking for the file
* system object it describes.
*
* VOP_FID() takes a vnode and provides a file ID (fid) that can later
* be presented (in a pair with a VFS pointer) to VFS_VGET() to
* reconstitute that vnode. In a Sun ONC-NFS style kernel, VOP_FID()
* is used twice per file handle, once for the exported directory and
* once for the object itself. In Linux, the NFS layer itself handles
* the export tree checking (depending on the status of
* NFSEXP_NOSUBTREECHECK), so the file system only needs to fill in
* the file handle with details for the object itself. We always
* provide both object and parent in the file handle to be sure that
* we don't end up short on file handle space in a future call that
* requires both.
*
* On a call from the NFS client, the Linux NFS layer finds a
* superblock pointer from the file handle passed by the NFS client,
* then calls the fh_to_dentry() method to get a dentry. Sun ONC-NFS
* kernels call VFS_VGET() on a vfsp, passing the FID portion of the
* file handle. In this layer, we unpack the file handle, determine
* whether the parent or the object is needed, and pass the info along
* to a VFS_VGET() call. Once that returns, we look for an attached
* dentry and use it, or fabricate a new one which NFS will attempt to
* reconnect to the namespace.
*/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
int
vnlayer_inode_to_fh(
struct inode *inode,
__u32 *fh,
int *lenp,
struct inode *parent
)
#else /* LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0) */
int
vnlayer_dentry_to_fh(
struct dentry *dent,
__u32 *fh,
int *lenp,
int need_parent
)
#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0) */
{
int error;
int type;
int mylen;
MDKI_FID_T *lfidp = NULL;
MDKI_FID_T *parent_fidp = NULL;
mdki_boolean_t bailout_needed = TRUE; /* Assume we'll fail. */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
SUPER_T *sbp;
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,5,0)
struct inode *inode = dent->d_inode;
struct inode *parent = dent->d_parent->d_inode;
#endif
/*
* We use the type byte (return value) to encode the FH length. Since we
* always include two FIDs of the same size, the type must be even, so
* that's how we "encode" the length of each FID (i.e. it is half the total
* length).
*
* Always include parent entry; this makes sure that we only work with NFS
* protocols that have enough room for our file handles. (Without this, we
* may return a directory file handle OK yet be unable to return a plain
* file handle.) Currently, we can just barely squeeze two standard
* 10-byte vnode FIDs into the NFS v2 file handle. The NFS v3 handle has
* plenty of room.
*/
ASSERT(ITOV(inode));
error = VOP_FID(ITOV(inode), &lfidp);
if (error != 0) {
ASSERT(lfidp == NULL);
goto bailout;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
/* we may be called with a NULL parent */
if (parent == NULL) {
/* in this case, fabricate a fake parent */
parent_fidp = (MDKI_FID_T *) KMEM_ALLOC(MDKI_FID_LEN(lfidp),
KM_SLEEP);
if (parent_fidp == NULL) {
MDKI_VFS_LOG(VFS_LOG_ERR, "%s: can't allocate %d bytes\n",
__func__,
(int) MDKI_FID_LEN(lfidp));
goto bailout;
}
memset(parent_fidp, 0xff, MDKI_FID_LEN(lfidp));
parent_fidp->fid_len = lfidp->fid_len;
} else
#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0) */
{
error = VOP_FID(ITOV(parent), &parent_fidp);
if (error != 0) {
ASSERT(parent_fidp == NULL);
goto bailout;
}
}
/*
* Our encoding scheme can't tolerate different length FIDs
* (because otherwise the type wouldn't be guaranteed to be even).
*/
if (parent_fidp->fid_len != lfidp->fid_len) {
MDKI_VFS_LOG(VFS_LOG_ERR,
"%s: unbalanced parent/child fid lengths: %d, %d\n",
__func__, parent_fidp->fid_len, lfidp->fid_len);
goto bailout;
}
/*
* vnode layer needs to release the storage for a fid on
* Linux. The VOP_FID() function allocates its own fid in
* non-error cases. Other UNIX systems release this storage
* in the caller of VOP_FID, so we have to do it here. We
* copy the vnode-style fid into the caller-allocated space,
* then free our allocated version here.