[mirror_ubuntu-bionic-kernel.git] / fs / afs / inode.c

/*
 * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
 *
 * This software may be freely redistributed under the terms of the
 * GNU General Public License.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Authors: David Woodhouse <dwmw2@cambridge.redhat.com>
 *          David Howells <dhowells@redhat.com>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include "internal.h"

struct afs_iget_data {
	struct afs_fid		fid;
	struct afs_volume	*volume;	/* volume on which resides */
};

/*
 * map the AFS file status to the inode member variables
 */
static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
{
	struct inode *inode = AFS_VNODE_TO_I(vnode);

	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
	       vnode->status.type,
	       vnode->status.nlink,
	       (unsigned long long) vnode->status.size,
	       vnode->status.data_version,
	       vnode->status.mode);

	switch (vnode->status.type) {
	case AFS_FTYPE_FILE:
		inode->i_mode	= S_IFREG | vnode->status.mode;
		inode->i_op	= &afs_file_inode_operations;
		inode->i_fop	= &afs_file_operations;
		break;
	case AFS_FTYPE_DIR:
		inode->i_mode	= S_IFDIR | vnode->status.mode;
		inode->i_op	= &afs_dir_inode_operations;
		inode->i_fop	= &afs_dir_file_operations;
		break;
	case AFS_FTYPE_SYMLINK:
		inode->i_mode	= S_IFLNK | vnode->status.mode;
		inode->i_op	= &page_symlink_inode_operations;
		break;
	default:
		printk("kAFS: AFS vnode with undefined type\n");
		return -EBADMSG;
	}

	inode->i_nlink		= vnode->status.nlink;
	inode->i_uid		= vnode->status.owner;
	inode->i_gid		= 0;
	inode->i_size		= vnode->status.size;
	inode->i_ctime.tv_sec	= vnode->status.mtime_server;
	inode->i_ctime.tv_nsec	= 0;
	inode->i_atime		= inode->i_mtime = inode->i_ctime;
	inode->i_blocks		= 0;
	inode->i_version	= vnode->fid.unique;
	inode->i_mapping->a_ops	= &afs_fs_aops;

	/* check to see whether a symbolic link is really a mountpoint */
	if (vnode->status.type == AFS_FTYPE_SYMLINK) {
		afs_mntpt_check_symlink(vnode, key);

		if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) {
			inode->i_mode	= S_IFDIR | vnode->status.mode;
			inode->i_op	= &afs_mntpt_inode_operations;
			inode->i_fop	= &afs_mntpt_file_operations;
		}
	}

	return 0;
}

/*
 * iget5() comparator
 */
static int afs_iget5_test(struct inode *inode, void *opaque)
{
	struct afs_iget_data *data = opaque;

	return inode->i_ino == data->fid.vnode &&
		inode->i_version == data->fid.unique;
}

/*
 * iget5() inode initialiser
 */
static int afs_iget5_set(struct inode *inode, void *opaque)
{
	struct afs_iget_data *data = opaque;
	struct afs_vnode *vnode = AFS_FS_I(inode);

	inode->i_ino = data->fid.vnode;
	inode->i_version = data->fid.unique;
	vnode->fid = data->fid;
	vnode->volume = data->volume;

	return 0;
}

/*
 * inode retrieval
 */
struct inode *afs_iget(struct super_block *sb, struct key *key,
		       struct afs_fid *fid, struct afs_file_status *status,
		       struct afs_callback *cb)
{
	struct afs_iget_data data = { .fid = *fid };
	struct afs_super_info *as;
	struct afs_vnode *vnode;
	struct inode *inode;
	int ret;

	_enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique);

	as = sb->s_fs_info;
	data.volume = as->volume;

	inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
			     &data);
	if (!inode) {
		_leave(" = -ENOMEM");
		return ERR_PTR(-ENOMEM);
	}

	_debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
	       inode, fid->vid, fid->vnode, fid->unique);

	vnode = AFS_FS_I(inode);

	/* deal with an existing inode */
	if (!(inode->i_state & I_NEW)) {
		_leave(" = %p", inode);
		return inode;
	}

#ifdef AFS_CACHING_SUPPORT
	/* set up caching before reading the status, as fetch-status reads the
	 * first page of symlinks to see if they're really mntpts */
	cachefs_acquire_cookie(vnode->volume->cache,
			       NULL,
			       vnode,
			       &vnode->cache);
#endif

	if (!status) {
		/* it's a remotely extant inode */
		set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
		ret = afs_vnode_fetch_status(vnode, NULL, key);
		if (ret < 0)
			goto bad_inode;
	} else {
		/* it's an inode we just created */
		memcpy(&vnode->status, status, sizeof(vnode->status));

		if (!cb) {
			/* it's a symlink we just created (the fileserver
			 * didn't give us a callback) */
			vnode->cb_version = 0;
			vnode->cb_expiry = 0;
			vnode->cb_type = 0;
			vnode->cb_expires = get_seconds();
		} else {
			vnode->cb_version = cb->version;
			vnode->cb_expiry = cb->expiry;
			vnode->cb_type = cb->type;
			vnode->cb_expires = vnode->cb_expiry + get_seconds();
		}
	}

	ret = afs_inode_map_status(vnode, key);
	if (ret < 0)
		goto bad_inode;

	/* success */
	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
	inode->i_flags |= S_NOATIME;
	unlock_new_inode(inode);
	_leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
	return inode;

	/* failure */
bad_inode:
	make_bad_inode(inode);
	unlock_new_inode(inode);
	iput(inode);

	_leave(" = %d [bad]", ret);
	return ERR_PTR(ret);
}

/*
 * validate a vnode/inode
 * - there are several things we need to check
 *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
 *     symlink)
 *   - parent dir metadata changed (security changes)
 *   - dentry data changed (write, truncate)
 *   - dentry metadata changed (security changes)
 */
int afs_validate(struct afs_vnode *vnode, struct key *key)
{
	int ret;

	_enter("{v={%x:%u} fl=%lx},%x",
	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
	       key_serial(key));

	if (vnode->cb_promised &&
	    !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
	    !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
	    !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
		if (vnode->cb_expires < get_seconds() + 10) {
			_debug("callback expired");
			set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
		} else {
			goto valid;
		}
	}

	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
		goto valid;

	mutex_lock(&vnode->validate_lock);

	/* if the promise has expired, we need to check the server again to get
	 * a new promise - note that if the (parent) directory's metadata was
	 * changed then the security may be different and we may no longer have
	 * access */
	if (!vnode->cb_promised ||
	    test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
		_debug("not promised");
		ret = afs_vnode_fetch_status(vnode, NULL, key);
		if (ret < 0)
			goto error_unlock;
		_debug("new promise [fl=%lx]", vnode->flags);
	}

	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
		_debug("file already deleted");
		ret = -ESTALE;
		goto error_unlock;
	}

	/* if the vnode's data version number changed then its contents are
	 * different */
	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
		_debug("zap data {%x:%d}", vnode->fid.vid, vnode->fid.vnode);
		invalidate_remote_inode(&vnode->vfs_inode);
	}

	clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
	mutex_unlock(&vnode->validate_lock);
valid:
	_leave(" = 0");
	return 0;

error_unlock:
	mutex_unlock(&vnode->validate_lock);
	_leave(" = %d", ret);
	return ret;
}

/*
 * read the attributes of an inode
 */
int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
		      struct kstat *stat)
{
	struct inode *inode;

	inode = dentry->d_inode;

	_enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);

	generic_fillattr(inode, stat);
	return 0;
}

/*
 * clear an AFS inode
 */
void afs_clear_inode(struct inode *inode)
{
	struct afs_permits *permits;
	struct afs_vnode *vnode;

	vnode = AFS_FS_I(inode);

	_enter("{%x:%d.%d} v=%u x=%u t=%u }",
	       vnode->fid.vid,
	       vnode->fid.vnode,
	       vnode->fid.unique,
	       vnode->cb_version,
	       vnode->cb_expiry,
	       vnode->cb_type);

	_debug("CLEAR INODE %p", inode);

	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);

	afs_give_up_callback(vnode);

	if (vnode->server) {
		spin_lock(&vnode->server->fs_lock);
		rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
		spin_unlock(&vnode->server->fs_lock);
		afs_put_server(vnode->server);
		vnode->server = NULL;
	}

	ASSERT(!vnode->cb_promised);

#ifdef AFS_CACHING_SUPPORT
	cachefs_relinquish_cookie(vnode->cache, 0);
	vnode->cache = NULL;
#endif

	mutex_lock(&vnode->permits_lock);
	permits = vnode->permits;
	rcu_assign_pointer(vnode->permits, NULL);
	mutex_unlock(&vnode->permits_lock);
	if (permits)
		call_rcu(&permits->rcu, afs_zap_permits);

	_leave("");
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (c) 2002 Red Hat, Inc. All rights reserved.
	3	*
	4	* This software may be freely redistributed under the terms of the
	5	* GNU General Public License.
	6	*
	7	* You should have received a copy of the GNU General Public License
	8	* along with this program; if not, write to the Free Software
	9	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	10	*
	11	* Authors: David Woodhouse <dwmw2@cambridge.redhat.com>
	12	* David Howells <dhowells@redhat.com>
	13	*
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/init.h>
1da177e4 LT	19	#include <linux/slab.h>
	20	#include <linux/fs.h>
	21	#include <linux/pagemap.h>
1da177e4 LT	22	#include "internal.h"
	23
	24	struct afs_iget_data {
	25	struct afs_fid fid;
	26	struct afs_volume volume; / volume on which resides */
	27	};
	28
1da177e4 LT	29	/*
	30	* map the AFS file status to the inode member variables
	31	*/
00d3b7a4	32	static int afs_inode_map_status(struct afs_vnode vnode, struct key key)
1da177e4 LT	33	{
	34	struct inode *inode = AFS_VNODE_TO_I(vnode);
	35
260a9803	36	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
1da177e4 LT	37	vnode->status.type,
1da177e4 LT	38	vnode->status.nlink,
ba3e0e1a	39	(unsigned long long) vnode->status.size,
08e0e7c8	40	vnode->status.data_version,
1da177e4 LT	41	vnode->status.mode);
	42
	43	switch (vnode->status.type) {
	44	case AFS_FTYPE_FILE:
	45	inode->i_mode = S_IFREG \| vnode->status.mode;
	46	inode->i_op = &afs_file_inode_operations;
00d3b7a4	47	inode->i_fop = &afs_file_operations;
1da177e4 LT	48	break;
	49	case AFS_FTYPE_DIR:
	50	inode->i_mode = S_IFDIR \| vnode->status.mode;
	51	inode->i_op = &afs_dir_inode_operations;
	52	inode->i_fop = &afs_dir_file_operations;
	53	break;
	54	case AFS_FTYPE_SYMLINK:
	55	inode->i_mode = S_IFLNK \| vnode->status.mode;
	56	inode->i_op = &page_symlink_inode_operations;
	57	break;
	58	default:
	59	printk("kAFS: AFS vnode with undefined type\n");
	60	return -EBADMSG;
	61	}
	62
	63	inode->i_nlink = vnode->status.nlink;
	64	inode->i_uid = vnode->status.owner;
	65	inode->i_gid = 0;
	66	inode->i_size = vnode->status.size;
	67	inode->i_ctime.tv_sec = vnode->status.mtime_server;
	68	inode->i_ctime.tv_nsec = 0;
	69	inode->i_atime = inode->i_mtime = inode->i_ctime;
1da177e4 LT	70	inode->i_blocks = 0;
	71	inode->i_version = vnode->fid.unique;
	72	inode->i_mapping->a_ops = &afs_fs_aops;
	73
	74	/* check to see whether a symbolic link is really a mountpoint */
	75	if (vnode->status.type == AFS_FTYPE_SYMLINK) {
00d3b7a4	76	afs_mntpt_check_symlink(vnode, key);
1da177e4	77
08e0e7c8	78	if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) {
1da177e4 LT	79	inode->i_mode = S_IFDIR \| vnode->status.mode;
	80	inode->i_op = &afs_mntpt_inode_operations;
	81	inode->i_fop = &afs_mntpt_file_operations;
	82	}
	83	}
	84
	85	return 0;
ec26815a	86	}
1da177e4	87
1da177e4 LT	88	/*
	89	* iget5() comparator
	90	*/
	91	static int afs_iget5_test(struct inode inode, void opaque)
	92	{
	93	struct afs_iget_data *data = opaque;
	94
	95	return inode->i_ino == data->fid.vnode &&
	96	inode->i_version == data->fid.unique;
ec26815a	97	}
1da177e4	98
1da177e4 LT	99	/*
	100	* iget5() inode initialiser
	101	*/
	102	static int afs_iget5_set(struct inode inode, void opaque)
	103	{
	104	struct afs_iget_data *data = opaque;
	105	struct afs_vnode *vnode = AFS_FS_I(inode);
	106
	107	inode->i_ino = data->fid.vnode;
	108	inode->i_version = data->fid.unique;
	109	vnode->fid = data->fid;
	110	vnode->volume = data->volume;
	111
	112	return 0;
ec26815a	113	}
1da177e4	114
1da177e4 LT	115	/*
	116	* inode retrieval
	117	*/
260a9803 DH	118	struct inode afs_iget(struct super_block sb, struct key *key,
	119	struct afs_fid fid, struct afs_file_status status,
	120	struct afs_callback *cb)
1da177e4 LT	121	{
	122	struct afs_iget_data data = { .fid = *fid };
	123	struct afs_super_info *as;
	124	struct afs_vnode *vnode;
	125	struct inode *inode;
	126	int ret;
	127
	128	_enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique);
	129
	130	as = sb->s_fs_info;
	131	data.volume = as->volume;
	132
	133	inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
	134	&data);
	135	if (!inode) {
	136	_leave(" = -ENOMEM");
08e0e7c8	137	return ERR_PTR(-ENOMEM);
1da177e4 LT	138	}
1da177e4 LT	139
08e0e7c8 DH	140	_debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
	141	inode, fid->vid, fid->vnode, fid->unique);
	142
1da177e4 LT	143	vnode = AFS_FS_I(inode);
	144
	145	/* deal with an existing inode */
	146	if (!(inode->i_state & I_NEW)) {
08e0e7c8 DH	147	_leave(" = %p", inode);
08e0e7c8 DH	148	return inode;
1da177e4 LT	149	}
	150
	151	#ifdef AFS_CACHING_SUPPORT
	152	/* set up caching before reading the status, as fetch-status reads the
	153	* first page of symlinks to see if they're really mntpts */
	154	cachefs_acquire_cookie(vnode->volume->cache,
	155	NULL,
	156	vnode,
	157	&vnode->cache);
	158	#endif
	159
260a9803 DH	160	if (!status) {
	161	/* it's a remotely extant inode */
	162	set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
	163	ret = afs_vnode_fetch_status(vnode, NULL, key);
	164	if (ret < 0)
	165	goto bad_inode;
	166	} else {
	167	/* it's an inode we just created */
	168	memcpy(&vnode->status, status, sizeof(vnode->status));
	169
	170	if (!cb) {
	171	/* it's a symlink we just created (the fileserver
	172	* didn't give us a callback) */
	173	vnode->cb_version = 0;
	174	vnode->cb_expiry = 0;
	175	vnode->cb_type = 0;
	176	vnode->cb_expires = get_seconds();
	177	} else {
	178	vnode->cb_version = cb->version;
	179	vnode->cb_expiry = cb->expiry;
	180	vnode->cb_type = cb->type;
	181	vnode->cb_expires = vnode->cb_expiry + get_seconds();
	182	}
	183	}
	184
00d3b7a4	185	ret = afs_inode_map_status(vnode, key);
08e0e7c8	186	if (ret < 0)
1da177e4 LT	187	goto bad_inode;
	188
	189	/* success */
260a9803	190	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
08e0e7c8	191	inode->i_flags \|= S_NOATIME;
1da177e4	192	unlock_new_inode(inode);
08e0e7c8 DH	193	_leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
08e0e7c8 DH	194	return inode;
1da177e4 LT	195
1da177e4 LT	196	/* failure */
ec26815a	197	bad_inode:
1da177e4 LT	198	make_bad_inode(inode);
	199	unlock_new_inode(inode);
	200	iput(inode);
	201
	202	_leave(" = %d [bad]", ret);
08e0e7c8	203	return ERR_PTR(ret);
ec26815a	204	}
1da177e4	205
260a9803 DH	206	/*
	207	* validate a vnode/inode
	208	* - there are several things we need to check
	209	* - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
	210	* symlink)
	211	* - parent dir metadata changed (security changes)
	212	* - dentry data changed (write, truncate)
	213	* - dentry metadata changed (security changes)
	214	*/
	215	int afs_validate(struct afs_vnode vnode, struct key key)
	216	{
	217	int ret;
	218
	219	_enter("{v={%x:%u} fl=%lx},%x",
	220	vnode->fid.vid, vnode->fid.vnode, vnode->flags,
	221	key_serial(key));
	222
	223	if (vnode->cb_promised &&
	224	!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
	225	!test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
	226	!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
	227	if (vnode->cb_expires < get_seconds() + 10) {
	228	_debug("callback expired");
	229	set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
	230	} else {
	231	goto valid;
	232	}
	233	}
	234
	235	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
	236	goto valid;
	237
	238	mutex_lock(&vnode->validate_lock);
	239
	240	/* if the promise has expired, we need to check the server again to get
	241	* a new promise - note that if the (parent) directory's metadata was
	242	* changed then the security may be different and we may no longer have
	243	* access */
	244	if (!vnode->cb_promised \|\|
	245	test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
	246	_debug("not promised");
	247	ret = afs_vnode_fetch_status(vnode, NULL, key);
	248	if (ret < 0)
	249	goto error_unlock;
	250	_debug("new promise [fl=%lx]", vnode->flags);
	251	}
	252
	253	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
	254	_debug("file already deleted");
	255	ret = -ESTALE;
	256	goto error_unlock;
	257	}
	258
	259	/* if the vnode's data version number changed then its contents are
	260	* different */
	261	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
	262	_debug("zap data {%x:%d}", vnode->fid.vid, vnode->fid.vnode);
	263	invalidate_remote_inode(&vnode->vfs_inode);
	264	}
	265
	266	clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
	267	mutex_unlock(&vnode->validate_lock);
	268	valid:
	269	_leave(" = 0");
270	return 0;
271
272	error_unlock:
273	mutex_unlock(&vnode->validate_lock);
274	_leave(" = %d", ret);
275	return ret;
276	}
277
1da177e4 LT	278	/*
	279	* read the attributes of an inode
	280	*/
	281	int afs_inode_getattr(struct vfsmount mnt, struct dentry dentry,
	282	struct kstat *stat)
	283	{
1da177e4	284	struct inode *inode;
1da177e4 LT	285
	286	inode = dentry->d_inode;
	287
	288	_enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);
	289
1da177e4	290	generic_fillattr(inode, stat);
1da177e4	291	return 0;
ec26815a	292	}
1da177e4	293
1da177e4 LT	294	/*
	295	* clear an AFS inode
	296	*/
	297	void afs_clear_inode(struct inode *inode)
	298	{
00d3b7a4	299	struct afs_permits *permits;
1da177e4 LT	300	struct afs_vnode *vnode;
	301
	302	vnode = AFS_FS_I(inode);
	303
260a9803 DH	304	_enter("{%x:%d.%d} v=%u x=%u t=%u }",
260a9803 DH	305	vnode->fid.vid,
1da177e4	306	vnode->fid.vnode,
260a9803	307	vnode->fid.unique,
1da177e4 LT	308	vnode->cb_version,
1da177e4 LT	309	vnode->cb_expiry,
08e0e7c8	310	vnode->cb_type);
1da177e4	311
08e0e7c8 DH	312	_debug("CLEAR INODE %p", inode);
	313
	314	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
	315
	316	afs_give_up_callback(vnode);
	317
	318	if (vnode->server) {
	319	spin_lock(&vnode->server->fs_lock);
	320	rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
	321	spin_unlock(&vnode->server->fs_lock);
	322	afs_put_server(vnode->server);
	323	vnode->server = NULL;
	324	}
1da177e4	325
08e0e7c8	326	ASSERT(!vnode->cb_promised);
1da177e4 LT	327
	328	#ifdef AFS_CACHING_SUPPORT
	329	cachefs_relinquish_cookie(vnode->cache, 0);
	330	vnode->cache = NULL;
	331	#endif
	332
00d3b7a4 DH	333	mutex_lock(&vnode->permits_lock);
	334	permits = vnode->permits;
	335	rcu_assign_pointer(vnode->permits, NULL);
	336	mutex_unlock(&vnode->permits_lock);
	337	if (permits)
	338	call_rcu(&permits->rcu, afs_zap_permits);
	339
1da177e4	340	_leave("");
ec26815a	341	}