[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@infradead.org>
 *          David Howells <dhowells@redhat.com>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include "internal.h"

static const struct inode_operations afs_symlink_inode_operations = {
	.get_link	= page_get_link,
	.listxattr	= afs_listxattr,
};

/*
 * 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);
	bool changed;

	_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);

	read_seqlock_excl(&vnode->cb_lock);

	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:
		/* Symlinks with a mode of 0644 are actually mountpoints. */
		if ((vnode->status.mode & 0777) == 0644) {
			inode->i_flags |= S_AUTOMOUNT;

			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);

			inode->i_mode	= S_IFDIR | 0555;
			inode->i_op	= &afs_mntpt_inode_operations;
			inode->i_fop	= &afs_mntpt_file_operations;
		} else {
			inode->i_mode	= S_IFLNK | vnode->status.mode;
			inode->i_op	= &afs_symlink_inode_operations;
		}
		inode_nohighmem(inode);
		break;
	default:
		printk("kAFS: AFS vnode with undefined type\n");
		read_sequnlock_excl(&vnode->cb_lock);
		return -EBADMSG;
	}

	changed = (vnode->status.size != inode->i_size);

	set_nlink(inode, vnode->status.nlink);
	inode->i_uid		= vnode->status.owner;
	inode->i_gid            = vnode->status.group;
	inode->i_size		= vnode->status.size;
	inode->i_ctime.tv_sec	= vnode->status.mtime_client;
	inode->i_ctime.tv_nsec	= 0;
	inode->i_atime		= inode->i_mtime = inode->i_ctime;
	inode->i_blocks		= 0;
	inode->i_generation	= vnode->fid.unique;
	inode->i_version	= vnode->status.data_version;
	inode->i_mapping->a_ops	= &afs_fs_aops;

	read_sequnlock_excl(&vnode->cb_lock);

#ifdef CONFIG_AFS_FSCACHE
	if (changed)
		fscache_attr_changed(vnode->cache);
#endif
	return 0;
}

/*
 * Fetch file status from the volume.
 */
int afs_fetch_status(struct afs_vnode *vnode, struct key *key)
{
	struct afs_fs_cursor fc;
	int ret;

	_enter("%s,{%x:%u.%u,S=%lx}",
	       vnode->volume->name,
	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
	       vnode->flags);

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key)) {
		while (afs_select_fileserver(&fc)) {
			fc.cb_break = vnode->cb_break + vnode->cb_s_break;
			afs_fs_fetch_file_status(&fc, NULL);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break);
		ret = afs_end_vnode_operation(&fc);
	}

	_leave(" = %d", ret);
	return ret;
}

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

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

/*
 * iget5() comparator for inode created by autocell operations
 *
 * These pseudo inodes don't match anything.
 */
static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
{
	return 0;
}

/*
 * 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_generation = data->fid.unique;
	vnode->fid = data->fid;
	vnode->volume = data->volume;

	return 0;
}

/*
 * inode retrieval for autocell
 */
struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
				int namesz, struct key *key)
{
	struct afs_iget_data data;
	struct afs_super_info *as;
	struct afs_vnode *vnode;
	struct super_block *sb;
	struct inode *inode;
	static atomic_t afs_autocell_ino;

	_enter("{%x:%u},%*.*s,",
	       AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
	       namesz, namesz, dev_name ?: "");

	sb = dir->i_sb;
	as = sb->s_fs_info;
	data.volume = as->volume;
	data.fid.vid = as->volume->vid;
	data.fid.unique = 0;
	data.fid.vnode = 0;

	inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
			     afs_iget5_autocell_test, afs_iget5_set,
			     &data);
	if (!inode) {
		_leave(" = -ENOMEM");
		return ERR_PTR(-ENOMEM);
	}

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

	vnode = AFS_FS_I(inode);

	/* there shouldn't be an existing inode */
	BUG_ON(!(inode->i_state & I_NEW));

	inode->i_size		= 0;
	inode->i_mode		= S_IFDIR | S_IRUGO | S_IXUGO;
	inode->i_op		= &afs_autocell_inode_operations;
	set_nlink(inode, 2);
	inode->i_uid		= GLOBAL_ROOT_UID;
	inode->i_gid		= GLOBAL_ROOT_GID;
	inode->i_ctime.tv_sec	= get_seconds();
	inode->i_ctime.tv_nsec	= 0;
	inode->i_atime		= inode->i_mtime = inode->i_ctime;
	inode->i_blocks		= 0;
	inode->i_version	= 0;
	inode->i_generation	= 0;

	set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
	set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
	inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
	unlock_new_inode(inode);
	_leave(" = %p", inode);
	return inode;
}

/*
 * 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_cb_interest *cbi)
{
	struct afs_iget_data data = { .fid = *fid };
	struct afs_super_info *as;
	struct afs_vnode *vnode;
	struct inode *inode;
	int ret;

	_enter(",{%x:%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;
	}

	if (!status) {
		/* it's a remotely extant inode */
		ret = afs_fetch_status(vnode, 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_type = 0;
			vnode->cb_expires_at = 0;
		} else {
			vnode->cb_version = cb->version;
			vnode->cb_type = cb->type;
			vnode->cb_expires_at = cb->expiry;
			vnode->cb_interest = afs_get_cb_interest(cbi);
			set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
		}

		vnode->cb_expires_at += ktime_get_real_seconds();
	}

	/* set up caching before mapping the status, as map-status reads the
	 * first page of symlinks to see if they're really mountpoints */
	inode->i_size = vnode->status.size;
#ifdef CONFIG_AFS_FSCACHE
	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
					      &afs_vnode_cache_index_def,
					      vnode, true);
#endif

	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:
#ifdef CONFIG_AFS_FSCACHE
	fscache_relinquish_cookie(vnode->cache, 0);
	vnode->cache = NULL;
#endif
	iget_failed(inode);
	_leave(" = %d [bad]", ret);
	return ERR_PTR(ret);
}

/*
 * mark the data attached to an inode as obsolete due to a write on the server
 * - might also want to ditch all the outstanding writes and dirty pages
 */
void afs_zap_data(struct afs_vnode *vnode)
{
	_enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);

	/* nuke all the non-dirty pages that aren't locked, mapped or being
	 * written back in a regular file and completely discard the pages in a
	 * directory or symlink */
	if (S_ISREG(vnode->vfs_inode.i_mode))
		invalidate_remote_inode(&vnode->vfs_inode);
	else
		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
}

/*
 * 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)
{
	time64_t now = ktime_get_real_seconds();
	bool valid = false;
	int ret;

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

	/* Quickly check the callback state.  Ideally, we'd use read_seqbegin
	 * here, but we have no way to pass the net namespace to the RCU
	 * cleanup for the server record.
	 */
	read_seqlock_excl(&vnode->cb_lock);

	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
		if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) {
			vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
		} else if (!test_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags) &&
			   !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
			   vnode->cb_expires_at - 10 > now) {
				valid = true;
		}
	} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
		valid = true;
	}

	read_sequnlock_excl(&vnode->cb_lock);

	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
		clear_nlink(&vnode->vfs_inode);

	if (valid)
		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 (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
		_debug("not promised");
		ret = afs_fetch_status(vnode, key);
		if (ret < 0) {
			if (ret == -ENOENT) {
				set_bit(AFS_VNODE_DELETED, &vnode->flags);
				ret = -ESTALE;
			}
			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))
		afs_zap_data(vnode);

	clear_bit(AFS_VNODE_DIR_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_getattr(const struct path *path, struct kstat *stat,
		u32 request_mask, unsigned int query_flags)
{
	struct inode *inode = d_inode(path->dentry);
	struct afs_vnode *vnode = AFS_FS_I(inode);
	int seq = 0;

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

	do {
		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
		generic_fillattr(inode, stat);
	} while (need_seqretry(&vnode->cb_lock, seq));

	done_seqretry(&vnode->cb_lock, seq);
	return 0;
}

/*
 * discard an AFS inode
 */
int afs_drop_inode(struct inode *inode)
{
	_enter("");

	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
		return generic_delete_inode(inode);
	else
		return generic_drop_inode(inode);
}

/*
 * clear an AFS inode
 */
void afs_evict_inode(struct inode *inode)
{
	struct afs_vnode *vnode;

	vnode = AFS_FS_I(inode);

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

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

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

	truncate_inode_pages_final(&inode->i_data);
	clear_inode(inode);

	if (vnode->cb_interest) {
		afs_put_cb_interest(afs_i2net(inode), vnode->cb_interest);
		vnode->cb_interest = NULL;
	}

	while (!list_empty(&vnode->wb_keys)) {
		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
						    struct afs_wb_key, vnode_link);
		list_del(&wbk->vnode_link);
		afs_put_wb_key(wbk);
	}

#ifdef CONFIG_AFS_FSCACHE
	fscache_relinquish_cookie(vnode->cache, 0);
	vnode->cache = NULL;
#endif

	afs_put_permits(vnode->permit_cache);
	_leave("");
}

/*
 * set the attributes of an inode
 */
int afs_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct afs_fs_cursor fc;
	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
	struct key *key;
	int ret;

	_enter("{%x:%u},{n=%pd},%x",
	       vnode->fid.vid, vnode->fid.vnode, dentry,
	       attr->ia_valid);

	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
				ATTR_MTIME))) {
		_leave(" = 0 [unsupported]");
		return 0;
	}

	/* flush any dirty data outstanding on a regular file */
	if (S_ISREG(vnode->vfs_inode.i_mode))
		filemap_write_and_wait(vnode->vfs_inode.i_mapping);

	if (attr->ia_valid & ATTR_FILE) {
		key = afs_file_key(attr->ia_file);
	} else {
		key = afs_request_key(vnode->volume->cell);
		if (IS_ERR(key)) {
			ret = PTR_ERR(key);
			goto error;
		}
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key)) {
		while (afs_select_fileserver(&fc)) {
			fc.cb_break = vnode->cb_break + vnode->cb_s_break;
			afs_fs_setattr(&fc, attr);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break);
		ret = afs_end_vnode_operation(&fc);
	}

	if (!(attr->ia_valid & ATTR_FILE))
		key_put(key);

error:
	_leave(" = %d", ret);
	return ret;
}
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	*
44d1b980	11	* Authors: David Woodhouse <dwmw2@infradead.org>
1da177e4 LT	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/fs.h>
1da177e4 LT	20	#include <linux/pagemap.h>
e8edc6e0	21	#include <linux/sched.h>
bec5eb61	22	#include <linux/mount.h>
bec5eb61	23	#include <linux/namei.h>
1da177e4 LT	24	#include "internal.h"
1da177e4 LT	25
d3e3b7ea DH	26	static const struct inode_operations afs_symlink_inode_operations = {
	27	.get_link = page_get_link,
	28	.listxattr = afs_listxattr,
	29	};
	30
1da177e4 LT	31	/*
	32	* map the AFS file status to the inode member variables
	33	*/
00d3b7a4	34	static int afs_inode_map_status(struct afs_vnode vnode, struct key key)
1da177e4 LT	35	{
1da177e4 LT	36	struct inode *inode = AFS_VNODE_TO_I(vnode);
c435ee34	37	bool changed;
1da177e4	38
260a9803	39	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
1da177e4 LT	40	vnode->status.type,
1da177e4 LT	41	vnode->status.nlink,
ba3e0e1a	42	(unsigned long long) vnode->status.size,
08e0e7c8	43	vnode->status.data_version,
1da177e4 LT	44	vnode->status.mode);
1da177e4 LT	45
c435ee34 DH	46	read_seqlock_excl(&vnode->cb_lock);
c435ee34 DH	47
1da177e4 LT	48	switch (vnode->status.type) {
	49	case AFS_FTYPE_FILE:
	50	inode->i_mode = S_IFREG \| vnode->status.mode;
	51	inode->i_op = &afs_file_inode_operations;
00d3b7a4	52	inode->i_fop = &afs_file_operations;
1da177e4 LT	53	break;
	54	case AFS_FTYPE_DIR:
	55	inode->i_mode = S_IFDIR \| vnode->status.mode;
	56	inode->i_op = &afs_dir_inode_operations;
	57	inode->i_fop = &afs_dir_file_operations;
	58	break;
	59	case AFS_FTYPE_SYMLINK:
944c74f4 DH	60	/* Symlinks with a mode of 0644 are actually mountpoints. */
	61	if ((vnode->status.mode & 0777) == 0644) {
	62	inode->i_flags \|= S_AUTOMOUNT;
	63
944c74f4	64	set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
944c74f4 DH	65
	66	inode->i_mode = S_IFDIR \| 0555;
	67	inode->i_op = &afs_mntpt_inode_operations;
	68	inode->i_fop = &afs_mntpt_file_operations;
	69	} else {
	70	inode->i_mode = S_IFLNK \| vnode->status.mode;
d3e3b7ea	71	inode->i_op = &afs_symlink_inode_operations;
944c74f4	72	}
21fc61c7	73	inode_nohighmem(inode);
1da177e4 LT	74	break;
	75	default:
	76	printk("kAFS: AFS vnode with undefined type\n");
c435ee34	77	read_sequnlock_excl(&vnode->cb_lock);
1da177e4 LT	78	return -EBADMSG;
	79	}
	80
c435ee34	81	changed = (vnode->status.size != inode->i_size);
9b3f26c9	82
bfe86848	83	set_nlink(inode, vnode->status.nlink);
1da177e4	84	inode->i_uid = vnode->status.owner;
6186f078	85	inode->i_gid = vnode->status.group;
1da177e4	86	inode->i_size = vnode->status.size;
ab94f5d0	87	inode->i_ctime.tv_sec = vnode->status.mtime_client;
1da177e4 LT	88	inode->i_ctime.tv_nsec = 0;
1da177e4 LT	89	inode->i_atime = inode->i_mtime = inode->i_ctime;
1da177e4	90	inode->i_blocks = 0;
d6e43f75 DH	91	inode->i_generation = vnode->fid.unique;
d6e43f75 DH	92	inode->i_version = vnode->status.data_version;
1da177e4	93	inode->i_mapping->a_ops = &afs_fs_aops;
c435ee34 DH	94
	95	read_sequnlock_excl(&vnode->cb_lock);
	96
	97	#ifdef CONFIG_AFS_FSCACHE
	98	if (changed)
	99	fscache_attr_changed(vnode->cache);
	100	#endif
1da177e4	101	return 0;
ec26815a	102	}
1da177e4	103
d2ddc776 DH	104	/*
	105	* Fetch file status from the volume.
	106	*/
	107	int afs_fetch_status(struct afs_vnode vnode, struct key key)
	108	{
	109	struct afs_fs_cursor fc;
	110	int ret;
	111
	112	_enter("%s,{%x:%u.%u,S=%lx}",
	113	vnode->volume->name,
	114	vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
	115	vnode->flags);
	116
	117	ret = -ERESTARTSYS;
	118	if (afs_begin_vnode_operation(&fc, vnode, key)) {
	119	while (afs_select_fileserver(&fc)) {
	120	fc.cb_break = vnode->cb_break + vnode->cb_s_break;
	121	afs_fs_fetch_file_status(&fc, NULL);
	122	}
	123
	124	afs_check_for_remote_deletion(&fc, fc.vnode);
	125	afs_vnode_commit_status(&fc, vnode, fc.cb_break);
	126	ret = afs_end_vnode_operation(&fc);
	127	}
	128
	129	_leave(" = %d", ret);
	130	return ret;
	131	}
	132
1da177e4 LT	133	/*
	134	* iget5() comparator
	135	*/
c435ee34	136	int afs_iget5_test(struct inode inode, void opaque)
1da177e4 LT	137	{
	138	struct afs_iget_data *data = opaque;
	139
	140	return inode->i_ino == data->fid.vnode &&
d6e43f75	141	inode->i_generation == data->fid.unique;
ec26815a	142	}
1da177e4	143
bec5eb61	144	/*
	145	* iget5() comparator for inode created by autocell operations
	146	*
	147	* These pseudo inodes don't match anything.
	148	*/
	149	static int afs_iget5_autocell_test(struct inode inode, void opaque)
	150	{
	151	return 0;
	152	}
	153
1da177e4 LT	154	/*
	155	* iget5() inode initialiser
	156	*/
	157	static int afs_iget5_set(struct inode inode, void opaque)
	158	{
	159	struct afs_iget_data *data = opaque;
	160	struct afs_vnode *vnode = AFS_FS_I(inode);
	161
	162	inode->i_ino = data->fid.vnode;
d6e43f75	163	inode->i_generation = data->fid.unique;
1da177e4 LT	164	vnode->fid = data->fid;
	165	vnode->volume = data->volume;
	166
	167	return 0;
ec26815a	168	}
1da177e4	169
bec5eb61	170	/*
	171	* inode retrieval for autocell
	172	*/
	173	struct inode afs_iget_autocell(struct inode dir, const char *dev_name,
	174	int namesz, struct key *key)
	175	{
	176	struct afs_iget_data data;
	177	struct afs_super_info *as;
	178	struct afs_vnode *vnode;
	179	struct super_block *sb;
	180	struct inode *inode;
	181	static atomic_t afs_autocell_ino;
	182
	183	_enter("{%x:%u},%.s,",
	184	AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
	185	namesz, namesz, dev_name ?: "");
	186
	187	sb = dir->i_sb;
	188	as = sb->s_fs_info;
	189	data.volume = as->volume;
	190	data.fid.vid = as->volume->vid;
	191	data.fid.unique = 0;
	192	data.fid.vnode = 0;
	193
	194	inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
	195	afs_iget5_autocell_test, afs_iget5_set,
	196	&data);
	197	if (!inode) {
	198	_leave(" = -ENOMEM");
	199	return ERR_PTR(-ENOMEM);
	200	}
	201
	202	_debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }",
	203	inode, inode->i_ino, data.fid.vid, data.fid.vnode,
	204	data.fid.unique);
	205
	206	vnode = AFS_FS_I(inode);
	207
	208	/* there shouldn't be an existing inode */
	209	BUG_ON(!(inode->i_state & I_NEW));
	210
	211	inode->i_size = 0;
	212	inode->i_mode = S_IFDIR \| S_IRUGO \| S_IXUGO;
	213	inode->i_op = &afs_autocell_inode_operations;
bfe86848	214	set_nlink(inode, 2);
a0a5386a EB	215	inode->i_uid = GLOBAL_ROOT_UID;
a0a5386a EB	216	inode->i_gid = GLOBAL_ROOT_GID;
bec5eb61	217	inode->i_ctime.tv_sec = get_seconds();
	218	inode->i_ctime.tv_nsec = 0;
	219	inode->i_atime = inode->i_mtime = inode->i_ctime;
	220	inode->i_blocks = 0;
	221	inode->i_version = 0;
	222	inode->i_generation = 0;
	223
	224	set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
d18610b0 DH	225	set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
d18610b0 DH	226	inode->i_flags \|= S_AUTOMOUNT \| S_NOATIME;
bec5eb61	227	unlock_new_inode(inode);
	228	_leave(" = %p", inode);
	229	return inode;
	230	}
	231
1da177e4 LT	232	/*
	233	* inode retrieval
	234	*/
260a9803 DH	235	struct inode afs_iget(struct super_block sb, struct key *key,
260a9803 DH	236	struct afs_fid fid, struct afs_file_status status,
d2ddc776	237	struct afs_callback cb, struct afs_cb_interest cbi)
1da177e4 LT	238	{
	239	struct afs_iget_data data = { .fid = *fid };
	240	struct afs_super_info *as;
	241	struct afs_vnode *vnode;
	242	struct inode *inode;
	243	int ret;
	244
416351f2	245	_enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique);
1da177e4 LT	246
	247	as = sb->s_fs_info;
	248	data.volume = as->volume;
	249
	250	inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
	251	&data);
	252	if (!inode) {
	253	_leave(" = -ENOMEM");
08e0e7c8	254	return ERR_PTR(-ENOMEM);
1da177e4 LT	255	}
1da177e4 LT	256
08e0e7c8 DH	257	_debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
	258	inode, fid->vid, fid->vnode, fid->unique);
	259
1da177e4 LT	260	vnode = AFS_FS_I(inode);
	261
	262	/* deal with an existing inode */
	263	if (!(inode->i_state & I_NEW)) {
08e0e7c8 DH	264	_leave(" = %p", inode);
08e0e7c8 DH	265	return inode;
1da177e4 LT	266	}
1da177e4 LT	267
260a9803 DH	268	if (!status) {
260a9803 DH	269	/* it's a remotely extant inode */
d2ddc776	270	ret = afs_fetch_status(vnode, key);
260a9803 DH	271	if (ret < 0)
	272	goto bad_inode;
	273	} else {
	274	/* it's an inode we just created */
	275	memcpy(&vnode->status, status, sizeof(vnode->status));
	276
	277	if (!cb) {
	278	/* it's a symlink we just created (the fileserver
	279	* didn't give us a callback) */
	280	vnode->cb_version = 0;
260a9803	281	vnode->cb_type = 0;
c435ee34	282	vnode->cb_expires_at = 0;
260a9803 DH	283	} else {
260a9803 DH	284	vnode->cb_version = cb->version;
260a9803	285	vnode->cb_type = cb->type;
c435ee34	286	vnode->cb_expires_at = cb->expiry;
d2ddc776	287	vnode->cb_interest = afs_get_cb_interest(cbi);
c435ee34	288	set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
260a9803	289	}
c435ee34 DH	290
c435ee34 DH	291	vnode->cb_expires_at += ktime_get_real_seconds();
260a9803 DH	292	}
260a9803 DH	293
9b3f26c9 DH	294	/* set up caching before mapping the status, as map-status reads the
	295	* first page of symlinks to see if they're really mountpoints */
	296	inode->i_size = vnode->status.size;
	297	#ifdef CONFIG_AFS_FSCACHE
	298	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
	299	&afs_vnode_cache_index_def,
94d30ae9	300	vnode, true);
9b3f26c9 DH	301	#endif
9b3f26c9 DH	302
00d3b7a4	303	ret = afs_inode_map_status(vnode, key);
08e0e7c8	304	if (ret < 0)
1da177e4 LT	305	goto bad_inode;
	306
	307	/* success */
260a9803	308	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
08e0e7c8	309	inode->i_flags \|= S_NOATIME;
1da177e4	310	unlock_new_inode(inode);
08e0e7c8 DH	311	_leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
08e0e7c8 DH	312	return inode;
1da177e4 LT	313
1da177e4 LT	314	/* failure */
ec26815a	315	bad_inode:
9b3f26c9 DH	316	#ifdef CONFIG_AFS_FSCACHE
	317	fscache_relinquish_cookie(vnode->cache, 0);
	318	vnode->cache = NULL;
	319	#endif
aa7fa240	320	iget_failed(inode);
1da177e4	321	_leave(" = %d [bad]", ret);
08e0e7c8	322	return ERR_PTR(ret);
ec26815a	323	}
1da177e4	324
416351f2 DH	325	/*
	326	* mark the data attached to an inode as obsolete due to a write on the server
	327	* - might also want to ditch all the outstanding writes and dirty pages
	328	*/
	329	void afs_zap_data(struct afs_vnode *vnode)
	330	{
0f300ca9	331	_enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
416351f2 DH	332
416351f2 DH	333	/* nuke all the non-dirty pages that aren't locked, mapped or being
0f300ca9 DH	334	* written back in a regular file and completely discard the pages in a
	335	* directory or symlink */
	336	if (S_ISREG(vnode->vfs_inode.i_mode))
	337	invalidate_remote_inode(&vnode->vfs_inode);
	338	else
	339	invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
416351f2 DH	340	}
416351f2 DH	341
260a9803 DH	342	/*
	343	* validate a vnode/inode
	344	* - there are several things we need to check
	345	* - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
	346	* symlink)
	347	* - parent dir metadata changed (security changes)
	348	* - dentry data changed (write, truncate)
	349	* - dentry metadata changed (security changes)
	350	*/
	351	int afs_validate(struct afs_vnode vnode, struct key key)
	352	{
c435ee34 DH	353	time64_t now = ktime_get_real_seconds();
c435ee34 DH	354	bool valid = false;
260a9803 DH	355	int ret;
	356
	357	_enter("{v={%x:%u} fl=%lx},%x",
	358	vnode->fid.vid, vnode->fid.vnode, vnode->flags,
	359	key_serial(key));
	360
c435ee34 DH	361	/* Quickly check the callback state. Ideally, we'd use read_seqbegin
	362	* here, but we have no way to pass the net namespace to the RCU
	363	* cleanup for the server record.
	364	*/
	365	read_seqlock_excl(&vnode->cb_lock);
	366
	367	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
	368	if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) {
	369	vnode->cb_s_break = vnode->cb_interest->server->cb_s_break;
	370	} else if (!test_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags) &&
	371	!test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
	372	vnode->cb_expires_at - 10 > now) {
	373	valid = true;
260a9803	374	}
c435ee34 DH	375	} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
c435ee34 DH	376	valid = true;
260a9803 DH	377	}
260a9803 DH	378
c435ee34	379	read_sequnlock_excl(&vnode->cb_lock);
440fbc3a DH	380
	381	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
	382	clear_nlink(&vnode->vfs_inode);
	383
c435ee34	384	if (valid)
260a9803 DH	385	goto valid;
	386
	387	mutex_lock(&vnode->validate_lock);
	388
	389	/* if the promise has expired, we need to check the server again to get
	390	* a new promise - note that if the (parent) directory's metadata was
	391	* changed then the security may be different and we may no longer have
	392	* access */
c435ee34	393	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
260a9803	394	_debug("not promised");
d2ddc776	395	ret = afs_fetch_status(vnode, key);
c435ee34 DH	396	if (ret < 0) {
	397	if (ret == -ENOENT) {
	398	set_bit(AFS_VNODE_DELETED, &vnode->flags);
	399	ret = -ESTALE;
	400	}
260a9803	401	goto error_unlock;
c435ee34	402	}
260a9803 DH	403	_debug("new promise [fl=%lx]", vnode->flags);
	404	}
	405
	406	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
	407	_debug("file already deleted");
	408	ret = -ESTALE;
	409	goto error_unlock;
	410	}
	411
	412	/* if the vnode's data version number changed then its contents are
	413	* different */
416351f2 DH	414	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
416351f2 DH	415	afs_zap_data(vnode);
260a9803	416
c435ee34	417	clear_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags);
260a9803 DH	418	mutex_unlock(&vnode->validate_lock);
	419	valid:
	420	_leave(" = 0");
	421	return 0;
	422
	423	error_unlock:
	424	mutex_unlock(&vnode->validate_lock);
	425	_leave(" = %d", ret);
	426	return ret;
	427	}
	428
1da177e4 LT	429	/*
	430	* read the attributes of an inode
	431	*/
a528d35e DH	432	int afs_getattr(const struct path path, struct kstat stat,
a528d35e DH	433	u32 request_mask, unsigned int query_flags)
1da177e4	434	{
a528d35e	435	struct inode *inode = d_inode(path->dentry);
c435ee34 DH	436	struct afs_vnode *vnode = AFS_FS_I(inode);
c435ee34 DH	437	int seq = 0;
1da177e4	438
d6e43f75	439	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
1da177e4	440
c435ee34 DH	441	do {
	442	read_seqbegin_or_lock(&vnode->cb_lock, &seq);
	443	generic_fillattr(inode, stat);
	444	} while (need_seqretry(&vnode->cb_lock, seq));
	445
	446	done_seqretry(&vnode->cb_lock, seq);
1da177e4	447	return 0;
ec26815a	448	}
1da177e4	449
bec5eb61	450	/*
	451	* discard an AFS inode
	452	*/
	453	int afs_drop_inode(struct inode *inode)
	454	{
	455	_enter("");
	456
	457	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
	458	return generic_delete_inode(inode);
	459	else
	460	return generic_drop_inode(inode);
	461	}
	462
1da177e4 LT	463	/*
	464	* clear an AFS inode
	465	*/
b57922d9	466	void afs_evict_inode(struct inode *inode)
1da177e4 LT	467	{
	468	struct afs_vnode *vnode;
	469
	470	vnode = AFS_FS_I(inode);
	471
c435ee34	472	_enter("{%x:%u.%d}",
260a9803	473	vnode->fid.vid,
1da177e4	474	vnode->fid.vnode,
c435ee34	475	vnode->fid.unique);
1da177e4	476
08e0e7c8 DH	477	_debug("CLEAR INODE %p", inode);
	478
	479	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
	480
91b0abe3	481	truncate_inode_pages_final(&inode->i_data);
dbd5768f	482	clear_inode(inode);
b57922d9	483
c435ee34 DH	484	if (vnode->cb_interest) {
	485	afs_put_cb_interest(afs_i2net(inode), vnode->cb_interest);
	486	vnode->cb_interest = NULL;
08e0e7c8	487	}
1da177e4	488
4343d008 DH	489	while (!list_empty(&vnode->wb_keys)) {
	490	struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
	491	struct afs_wb_key, vnode_link);
	492	list_del(&wbk->vnode_link);
	493	afs_put_wb_key(wbk);
	494	}
1da177e4	495
9b3f26c9 DH	496	#ifdef CONFIG_AFS_FSCACHE
9b3f26c9 DH	497	fscache_relinquish_cookie(vnode->cache, 0);
1da177e4 LT	498	vnode->cache = NULL;
	499	#endif
	500
be080a6f	501	afs_put_permits(vnode->permit_cache);
1da177e4	502	_leave("");
ec26815a	503	}
31143d5d DH	504
	505	/*
	506	* set the attributes of an inode
	507	*/
	508	int afs_setattr(struct dentry dentry, struct iattr attr)
	509	{
d2ddc776	510	struct afs_fs_cursor fc;
2b0143b5	511	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
31143d5d DH	512	struct key *key;
	513	int ret;
	514
a455589f AV	515	_enter("{%x:%u},{n=%pd},%x",
a455589f AV	516	vnode->fid.vid, vnode->fid.vnode, dentry,
31143d5d DH	517	attr->ia_valid);
	518
	519	if (!(attr->ia_valid & (ATTR_SIZE \| ATTR_MODE \| ATTR_UID \| ATTR_GID \|
	520	ATTR_MTIME))) {
	521	_leave(" = 0 [unsupported]");
	522	return 0;
	523	}
	524
	525	/* flush any dirty data outstanding on a regular file */
4343d008	526	if (S_ISREG(vnode->vfs_inode.i_mode))
31143d5d	527	filemap_write_and_wait(vnode->vfs_inode.i_mapping);
31143d5d DH	528
31143d5d DH	529	if (attr->ia_valid & ATTR_FILE) {
215804a9	530	key = afs_file_key(attr->ia_file);
31143d5d DH	531	} else {
	532	key = afs_request_key(vnode->volume->cell);
	533	if (IS_ERR(key)) {
	534	ret = PTR_ERR(key);
	535	goto error;
	536	}
	537	}
	538
d2ddc776 DH	539	ret = -ERESTARTSYS;
	540	if (afs_begin_vnode_operation(&fc, vnode, key)) {
	541	while (afs_select_fileserver(&fc)) {
	542	fc.cb_break = vnode->cb_break + vnode->cb_s_break;
	543	afs_fs_setattr(&fc, attr);
	544	}
	545
	546	afs_check_for_remote_deletion(&fc, fc.vnode);
	547	afs_vnode_commit_status(&fc, vnode, fc.cb_break);
	548	ret = afs_end_vnode_operation(&fc);
	549	}
	550
31143d5d DH	551	if (!(attr->ia_valid & ATTR_FILE))
	552	key_put(key);
	553
	554	error:
	555	_leave(" = %d", ret);
	556	return ret;
	557	}