[linux.git] / fs / ceph / locks.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>

#include <linux/file.h>
#include <linux/namei.h>
#include <linux/random.h>

#include "super.h"
#include "mds_client.h"
#include <linux/ceph/pagelist.h>

static u64 lock_secret;
static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
                                         struct ceph_mds_request *req);

static inline u64 secure_addr(void *addr)
{
	u64 v = lock_secret ^ (u64)(unsigned long)addr;
	/*
	 * Set the most significant bit, so that MDS knows the 'owner'
	 * is sufficient to identify the owner of lock. (old code uses
	 * both 'owner' and 'pid')
	 */
	v |= (1ULL << 63);
	return v;
}

void __init ceph_flock_init(void)
{
	get_random_bytes(&lock_secret, sizeof(lock_secret));
}

static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
{
	struct inode *inode = file_inode(src->fl_file);
	atomic_inc(&ceph_inode(inode)->i_filelock_ref);
}

static void ceph_fl_release_lock(struct file_lock *fl)
{
	struct inode *inode = file_inode(fl->fl_file);
	struct ceph_inode_info *ci = ceph_inode(inode);
	if (atomic_dec_and_test(&ci->i_filelock_ref)) {
		/* clear error when all locks are released */
		spin_lock(&ci->i_ceph_lock);
		ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK;
		spin_unlock(&ci->i_ceph_lock);
	}
}

static const struct file_lock_operations ceph_fl_lock_ops = {
	.fl_copy_lock = ceph_fl_copy_lock,
	.fl_release_private = ceph_fl_release_lock,
};

/**
 * Implement fcntl and flock locking functions.
 */
static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode,
			     int cmd, u8 wait, struct file_lock *fl)
{
	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
	struct ceph_mds_request *req;
	int err;
	u64 length = 0;
	u64 owner;

	if (operation == CEPH_MDS_OP_SETFILELOCK) {
		/*
		 * increasing i_filelock_ref closes race window between
		 * handling request reply and adding file_lock struct to
		 * inode. Otherwise, auth caps may get trimmed in the
		 * window. Caller function will decrease the counter.
		 */
		fl->fl_ops = &ceph_fl_lock_ops;
		atomic_inc(&ceph_inode(inode)->i_filelock_ref);
	}

	if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK)
		wait = 0;

	req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS);
	if (IS_ERR(req))
		return PTR_ERR(req);
	req->r_inode = inode;
	ihold(inode);
	req->r_num_caps = 1;

	/* mds requires start and length rather than start and end */
	if (LLONG_MAX == fl->fl_end)
		length = 0;
	else
		length = fl->fl_end - fl->fl_start + 1;

	owner = secure_addr(fl->fl_owner);

	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
	     "start: %llu, length: %llu, wait: %d, type: %d\n", (int)lock_type,
	     (int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length,
	     wait, fl->fl_type);

	req->r_args.filelock_change.rule = lock_type;
	req->r_args.filelock_change.type = cmd;
	req->r_args.filelock_change.owner = cpu_to_le64(owner);
	req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid);
	req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start);
	req->r_args.filelock_change.length = cpu_to_le64(length);
	req->r_args.filelock_change.wait = wait;

	if (wait)
		req->r_wait_for_completion = ceph_lock_wait_for_completion;

	err = ceph_mdsc_do_request(mdsc, inode, req);

	if (operation == CEPH_MDS_OP_GETFILELOCK) {
		fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid);
		if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type)
			fl->fl_type = F_RDLCK;
		else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type)
			fl->fl_type = F_WRLCK;
		else
			fl->fl_type = F_UNLCK;

		fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start);
		length = le64_to_cpu(req->r_reply_info.filelock_reply->start) +
						 le64_to_cpu(req->r_reply_info.filelock_reply->length);
		if (length >= 1)
			fl->fl_end = length -1;
		else
			fl->fl_end = 0;

	}
	ceph_mdsc_put_request(req);
	dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
	     "length: %llu, wait: %d, type: %d, err code %d\n", (int)lock_type,
	     (int)operation, (u64)fl->fl_pid, fl->fl_start,
	     length, wait, fl->fl_type, err);
	return err;
}

static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
                                         struct ceph_mds_request *req)
{
	struct ceph_mds_request *intr_req;
	struct inode *inode = req->r_inode;
	int err, lock_type;

	BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK);
	if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL)
		lock_type = CEPH_LOCK_FCNTL_INTR;
	else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK)
		lock_type = CEPH_LOCK_FLOCK_INTR;
	else
		BUG_ON(1);
	BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK);

	err = wait_for_completion_interruptible(&req->r_completion);
	if (!err)
		return 0;

	dout("ceph_lock_wait_for_completion: request %llu was interrupted\n",
	     req->r_tid);

	mutex_lock(&mdsc->mutex);
	if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
		err = 0;
	} else {
		/*
		 * ensure we aren't running concurrently with
		 * ceph_fill_trace or ceph_readdir_prepopulate, which
		 * rely on locks (dir mutex) held by our caller.
		 */
		mutex_lock(&req->r_fill_mutex);
		req->r_err = err;
		set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
		mutex_unlock(&req->r_fill_mutex);

		if (!req->r_session) {
			// haven't sent the request
			err = 0;
		}
	}
	mutex_unlock(&mdsc->mutex);
	if (!err)
		return 0;

	intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK,
					    USE_AUTH_MDS);
	if (IS_ERR(intr_req))
		return PTR_ERR(intr_req);

	intr_req->r_inode = inode;
	ihold(inode);
	intr_req->r_num_caps = 1;

	intr_req->r_args.filelock_change = req->r_args.filelock_change;
	intr_req->r_args.filelock_change.rule = lock_type;
	intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK;

	err = ceph_mdsc_do_request(mdsc, inode, intr_req);
	ceph_mdsc_put_request(intr_req);

	if (err && err != -ERESTARTSYS)
		return err;

	wait_for_completion_killable(&req->r_safe_completion);
	return 0;
}

/**
 * Attempt to set an fcntl lock.
 * For now, this just goes away to the server. Later it may be more awesome.
 */
int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
{
	struct inode *inode = file_inode(file);
	struct ceph_inode_info *ci = ceph_inode(inode);
	int err = 0;
	u16 op = CEPH_MDS_OP_SETFILELOCK;
	u8 wait = 0;
	u8 lock_cmd;

	if (!(fl->fl_flags & FL_POSIX))
		return -ENOLCK;
	/* No mandatory locks */
	if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK)
		return -ENOLCK;

	dout("ceph_lock, fl_owner: %p\n", fl->fl_owner);

	/* set wait bit as appropriate, then make command as Ceph expects it*/
	if (IS_GETLK(cmd))
		op = CEPH_MDS_OP_GETFILELOCK;
	else if (IS_SETLKW(cmd))
		wait = 1;

	spin_lock(&ci->i_ceph_lock);
	if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) {
		err = -EIO;
	} else if (op == CEPH_MDS_OP_SETFILELOCK) {
		/*
		 * increasing i_filelock_ref closes race window between
		 * handling request reply and adding file_lock struct to
		 * inode. Otherwise, i_auth_cap may get trimmed in the
		 * window. Caller function will decrease the counter.
		 */
		fl->fl_ops = &ceph_fl_lock_ops;
		atomic_inc(&ci->i_filelock_ref);
	}
	spin_unlock(&ci->i_ceph_lock);
	if (err < 0) {
		if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type)
			posix_lock_file(file, fl, NULL);
		return err;
	}

	if (F_RDLCK == fl->fl_type)
		lock_cmd = CEPH_LOCK_SHARED;
	else if (F_WRLCK == fl->fl_type)
		lock_cmd = CEPH_LOCK_EXCL;
	else
		lock_cmd = CEPH_LOCK_UNLOCK;

	err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl);
	if (!err) {
		if (op == CEPH_MDS_OP_SETFILELOCK) {
			dout("mds locked, locking locally\n");
			err = posix_lock_file(file, fl, NULL);
			if (err) {
				/* undo! This should only happen if
				 * the kernel detects local
				 * deadlock. */
				ceph_lock_message(CEPH_LOCK_FCNTL, op, inode,
						  CEPH_LOCK_UNLOCK, 0, fl);
				dout("got %d on posix_lock_file, undid lock\n",
				     err);
			}
		}
	}
	return err;
}

int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
{
	struct inode *inode = file_inode(file);
	struct ceph_inode_info *ci = ceph_inode(inode);
	int err = 0;
	u8 wait = 0;
	u8 lock_cmd;

	if (!(fl->fl_flags & FL_FLOCK))
		return -ENOLCK;
	/* No mandatory locks */
	if (fl->fl_type & LOCK_MAND)
		return -EOPNOTSUPP;

	dout("ceph_flock, fl_file: %p\n", fl->fl_file);

	spin_lock(&ci->i_ceph_lock);
	if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) {
		err = -EIO;
	} else {
		/* see comment in ceph_lock */
		fl->fl_ops = &ceph_fl_lock_ops;
		atomic_inc(&ci->i_filelock_ref);
	}
	spin_unlock(&ci->i_ceph_lock);
	if (err < 0) {
		if (F_UNLCK == fl->fl_type)
			locks_lock_file_wait(file, fl);
		return err;
	}

	if (IS_SETLKW(cmd))
		wait = 1;

	if (F_RDLCK == fl->fl_type)
		lock_cmd = CEPH_LOCK_SHARED;
	else if (F_WRLCK == fl->fl_type)
		lock_cmd = CEPH_LOCK_EXCL;
	else
		lock_cmd = CEPH_LOCK_UNLOCK;

	err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
				inode, lock_cmd, wait, fl);
	if (!err) {
		err = locks_lock_file_wait(file, fl);
		if (err) {
			ceph_lock_message(CEPH_LOCK_FLOCK,
					  CEPH_MDS_OP_SETFILELOCK,
					  inode, CEPH_LOCK_UNLOCK, 0, fl);
			dout("got %d on locks_lock_file_wait, undid lock\n", err);
		}
	}
	return err;
}

/*
 * Fills in the passed counter variables, so you can prepare pagelist metadata
 * before calling ceph_encode_locks.
 */
void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count)
{
	struct file_lock *lock;
	struct file_lock_context *ctx;

	*fcntl_count = 0;
	*flock_count = 0;

	ctx = inode->i_flctx;
	if (ctx) {
		spin_lock(&ctx->flc_lock);
		list_for_each_entry(lock, &ctx->flc_posix, fl_list)
			++(*fcntl_count);
		list_for_each_entry(lock, &ctx->flc_flock, fl_list)
			++(*flock_count);
		spin_unlock(&ctx->flc_lock);
	}
	dout("counted %d flock locks and %d fcntl locks\n",
	     *flock_count, *fcntl_count);
}

/*
 * Given a pointer to a lock, convert it to a ceph filelock
 */
static int lock_to_ceph_filelock(struct file_lock *lock,
				 struct ceph_filelock *cephlock)
{
	int err = 0;
	cephlock->start = cpu_to_le64(lock->fl_start);
	cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
	cephlock->client = cpu_to_le64(0);
	cephlock->pid = cpu_to_le64((u64)lock->fl_pid);
	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));

	switch (lock->fl_type) {
	case F_RDLCK:
		cephlock->type = CEPH_LOCK_SHARED;
		break;
	case F_WRLCK:
		cephlock->type = CEPH_LOCK_EXCL;
		break;
	case F_UNLCK:
		cephlock->type = CEPH_LOCK_UNLOCK;
		break;
	default:
		dout("Have unknown lock type %d\n", lock->fl_type);
		err = -EINVAL;
	}

	return err;
}

/**
 * Encode the flock and fcntl locks for the given inode into the ceph_filelock
 * array. Must be called with inode->i_lock already held.
 * If we encounter more of a specific lock type than expected, return -ENOSPC.
 */
int ceph_encode_locks_to_buffer(struct inode *inode,
				struct ceph_filelock *flocks,
				int num_fcntl_locks, int num_flock_locks)
{
	struct file_lock *lock;
	struct file_lock_context *ctx = inode->i_flctx;
	int err = 0;
	int seen_fcntl = 0;
	int seen_flock = 0;
	int l = 0;

	dout("encoding %d flock and %d fcntl locks\n", num_flock_locks,
	     num_fcntl_locks);

	if (!ctx)
		return 0;

	spin_lock(&ctx->flc_lock);
	list_for_each_entry(lock, &ctx->flc_posix, fl_list) {
		++seen_fcntl;
		if (seen_fcntl > num_fcntl_locks) {
			err = -ENOSPC;
			goto fail;
		}
		err = lock_to_ceph_filelock(lock, &flocks[l]);
		if (err)
			goto fail;
		++l;
	}
	list_for_each_entry(lock, &ctx->flc_flock, fl_list) {
		++seen_flock;
		if (seen_flock > num_flock_locks) {
			err = -ENOSPC;
			goto fail;
		}
		err = lock_to_ceph_filelock(lock, &flocks[l]);
		if (err)
			goto fail;
		++l;
	}
fail:
	spin_unlock(&ctx->flc_lock);
	return err;
}

/**
 * Copy the encoded flock and fcntl locks into the pagelist.
 * Format is: #fcntl locks, sequential fcntl locks, #flock locks,
 * sequential flock locks.
 * Returns zero on success.
 */
int ceph_locks_to_pagelist(struct ceph_filelock *flocks,
			   struct ceph_pagelist *pagelist,
			   int num_fcntl_locks, int num_flock_locks)
{
	int err = 0;
	__le32 nlocks;

	nlocks = cpu_to_le32(num_fcntl_locks);
	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
	if (err)
		goto out_fail;

	if (num_fcntl_locks > 0) {
		err = ceph_pagelist_append(pagelist, flocks,
					   num_fcntl_locks * sizeof(*flocks));
		if (err)
			goto out_fail;
	}

	nlocks = cpu_to_le32(num_flock_locks);
	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
	if (err)
		goto out_fail;

	if (num_flock_locks > 0) {
		err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks],
					   num_flock_locks * sizeof(*flocks));
	}
out_fail:
	return err;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
3d14c5d2	2	#include <linux/ceph/ceph_debug.h>
40819f6f GF	3
	4	#include <linux/file.h>
	5	#include <linux/namei.h>
eb13e832	6	#include <linux/random.h>
40819f6f GF	7
	8	#include "super.h"
	9	#include "mds_client.h"
3d14c5d2	10	#include <linux/ceph/pagelist.h>
40819f6f	11
eb13e832	12	static u64 lock_secret;
9280be24 YZ	13	static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
9280be24 YZ	14	struct ceph_mds_request *req);
eb13e832 YZ	15
	16	static inline u64 secure_addr(void *addr)
	17	{
	18	u64 v = lock_secret ^ (u64)(unsigned long)addr;
	19	/*
	20	* Set the most significant bit, so that MDS knows the 'owner'
	21	* is sufficient to identify the owner of lock. (old code uses
	22	* both 'owner' and 'pid')
	23	*/
	24	v \|= (1ULL << 63);
	25	return v;
	26	}
	27
	28	void __init ceph_flock_init(void)
	29	{
	30	get_random_bytes(&lock_secret, sizeof(lock_secret));
	31	}
	32
89aa5930 YZ	33	static void ceph_fl_copy_lock(struct file_lock dst, struct file_lock src)
	34	{
	35	struct inode *inode = file_inode(src->fl_file);
	36	atomic_inc(&ceph_inode(inode)->i_filelock_ref);
	37	}
	38
	39	static void ceph_fl_release_lock(struct file_lock *fl)
	40	{
	41	struct inode *inode = file_inode(fl->fl_file);
b3f8d68f YZ	42	struct ceph_inode_info *ci = ceph_inode(inode);
	43	if (atomic_dec_and_test(&ci->i_filelock_ref)) {
	44	/* clear error when all locks are released */
	45	spin_lock(&ci->i_ceph_lock);
	46	ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK;
	47	spin_unlock(&ci->i_ceph_lock);
	48	}
89aa5930 YZ	49	}
	50
	51	static const struct file_lock_operations ceph_fl_lock_ops = {
	52	.fl_copy_lock = ceph_fl_copy_lock,
	53	.fl_release_private = ceph_fl_release_lock,
	54	};
	55
40819f6f GF	56	/**
	57	* Implement fcntl and flock locking functions.
	58	*/
89aa5930	59	static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode,
637ae8d5	60	int cmd, u8 wait, struct file_lock *fl)
40819f6f	61	{
eb13e832	62	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
40819f6f GF	63	struct ceph_mds_request *req;
40819f6f GF	64	int err;
637ae8d5	65	u64 length = 0;
eb13e832	66	u64 owner;
40819f6f	67
89aa5930 YZ	68	if (operation == CEPH_MDS_OP_SETFILELOCK) {
	69	/*
	70	* increasing i_filelock_ref closes race window between
	71	* handling request reply and adding file_lock struct to
	72	* inode. Otherwise, auth caps may get trimmed in the
	73	* window. Caller function will decrease the counter.
	74	*/
	75	fl->fl_ops = &ceph_fl_lock_ops;
	76	atomic_inc(&ceph_inode(inode)->i_filelock_ref);
	77	}
	78
9280be24 YZ	79	if (operation != CEPH_MDS_OP_SETFILELOCK \|\| cmd == CEPH_LOCK_UNLOCK)
	80	wait = 0;
	81
40819f6f GF	82	req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS);
	83	if (IS_ERR(req))
	84	return PTR_ERR(req);
70b666c3 SW	85	req->r_inode = inode;
70b666c3 SW	86	ihold(inode);
3bd58143	87	req->r_num_caps = 1;
40819f6f	88
637ae8d5 HS	89	/* mds requires start and length rather than start and end */
	90	if (LLONG_MAX == fl->fl_end)
	91	length = 0;
	92	else
	93	length = fl->fl_end - fl->fl_start + 1;
	94
130d1f95	95	owner = secure_addr(fl->fl_owner);
eb13e832 YZ	96
eb13e832 YZ	97	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
4c069a58	98	"start: %llu, length: %llu, wait: %d, type: %d\n", (int)lock_type,
eb13e832 YZ	99	(int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length,
eb13e832 YZ	100	wait, fl->fl_type);
637ae8d5	101
40819f6f GF	102	req->r_args.filelock_change.rule = lock_type;
40819f6f GF	103	req->r_args.filelock_change.type = cmd;
eb13e832	104	req->r_args.filelock_change.owner = cpu_to_le64(owner);
637ae8d5	105	req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid);
637ae8d5	106	req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start);
40819f6f GF	107	req->r_args.filelock_change.length = cpu_to_le64(length);
	108	req->r_args.filelock_change.wait = wait;
	109
9280be24 YZ	110	if (wait)
	111	req->r_wait_for_completion = ceph_lock_wait_for_completion;
	112
40819f6f	113	err = ceph_mdsc_do_request(mdsc, inode, req);
a5b10629	114
eb13e832	115	if (operation == CEPH_MDS_OP_GETFILELOCK) {
9d5b86ac	116	fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid);
a5b10629 HS	117	if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type)
	118	fl->fl_type = F_RDLCK;
	119	else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type)
	120	fl->fl_type = F_WRLCK;
	121	else
	122	fl->fl_type = F_UNLCK;
	123
	124	fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start);
	125	length = le64_to_cpu(req->r_reply_info.filelock_reply->start) +
	126	le64_to_cpu(req->r_reply_info.filelock_reply->length);
	127	if (length >= 1)
	128	fl->fl_end = length -1;
	129	else
	130	fl->fl_end = 0;
	131
	132	}
40819f6f GF	133	ceph_mdsc_put_request(req);
40819f6f GF	134	dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
4c069a58	135	"length: %llu, wait: %d, type: %d, err code %d\n", (int)lock_type,
637ae8d5 HS	136	(int)operation, (u64)fl->fl_pid, fl->fl_start,
637ae8d5 HS	137	length, wait, fl->fl_type, err);
40819f6f GF	138	return err;
	139	}
	140
9280be24 YZ	141	static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
	142	struct ceph_mds_request *req)
	143	{
	144	struct ceph_mds_request *intr_req;
	145	struct inode *inode = req->r_inode;
	146	int err, lock_type;
	147
	148	BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK);
	149	if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL)
	150	lock_type = CEPH_LOCK_FCNTL_INTR;
	151	else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK)
	152	lock_type = CEPH_LOCK_FLOCK_INTR;
	153	else
	154	BUG_ON(1);
	155	BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK);
	156
	157	err = wait_for_completion_interruptible(&req->r_completion);
	158	if (!err)
	159	return 0;
	160
	161	dout("ceph_lock_wait_for_completion: request %llu was interrupted\n",
	162	req->r_tid);
	163
92e57e62 YZ	164	mutex_lock(&mdsc->mutex);
	165	if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
	166	err = 0;
	167	} else {
	168	/*
	169	* ensure we aren't running concurrently with
	170	* ceph_fill_trace or ceph_readdir_prepopulate, which
	171	* rely on locks (dir mutex) held by our caller.
	172	*/
	173	mutex_lock(&req->r_fill_mutex);
	174	req->r_err = err;
	175	set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
	176	mutex_unlock(&req->r_fill_mutex);
	177
	178	if (!req->r_session) {
	179	// haven't sent the request
	180	err = 0;
	181	}
	182	}
	183	mutex_unlock(&mdsc->mutex);
	184	if (!err)
	185	return 0;
	186
9280be24 YZ	187	intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK,
	188	USE_AUTH_MDS);
	189	if (IS_ERR(intr_req))
	190	return PTR_ERR(intr_req);
	191
	192	intr_req->r_inode = inode;
	193	ihold(inode);
	194	intr_req->r_num_caps = 1;
	195
	196	intr_req->r_args.filelock_change = req->r_args.filelock_change;
	197	intr_req->r_args.filelock_change.rule = lock_type;
	198	intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK;
	199
	200	err = ceph_mdsc_do_request(mdsc, inode, intr_req);
	201	ceph_mdsc_put_request(intr_req);
	202
	203	if (err && err != -ERESTARTSYS)
	204	return err;
	205
92e57e62	206	wait_for_completion_killable(&req->r_safe_completion);
9280be24 YZ	207	return 0;
	208	}
	209
40819f6f GF	210	/**
	211	* Attempt to set an fcntl lock.
	212	* For now, this just goes away to the server. Later it may be more awesome.
	213	*/
	214	int ceph_lock(struct file file, int cmd, struct file_lock fl)
	215	{
89aa5930	216	struct inode *inode = file_inode(file);
b3f8d68f YZ	217	struct ceph_inode_info *ci = ceph_inode(inode);
b3f8d68f YZ	218	int err = 0;
40819f6f	219	u16 op = CEPH_MDS_OP_SETFILELOCK;
89aa5930	220	u8 wait = 0;
b3f8d68f	221	u8 lock_cmd;
40819f6f	222
eb70c0ce YZ	223	if (!(fl->fl_flags & FL_POSIX))
	224	return -ENOLCK;
	225	/* No mandatory locks */
	226	if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK)
	227	return -ENOLCK;
	228
4c069a58	229	dout("ceph_lock, fl_owner: %p\n", fl->fl_owner);
40819f6f GF	230
40819f6f GF	231	/* set wait bit as appropriate, then make command as Ceph expects it*/
0e8e95d6	232	if (IS_GETLK(cmd))
40819f6f	233	op = CEPH_MDS_OP_GETFILELOCK;
0e8e95d6 YZ	234	else if (IS_SETLKW(cmd))
0e8e95d6 YZ	235	wait = 1;
40819f6f	236
b3f8d68f YZ	237	spin_lock(&ci->i_ceph_lock);
	238	if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) {
	239	err = -EIO;
	240	} else if (op == CEPH_MDS_OP_SETFILELOCK) {
89aa5930 YZ	241	/*
	242	* increasing i_filelock_ref closes race window between
	243	* handling request reply and adding file_lock struct to
	244	* inode. Otherwise, i_auth_cap may get trimmed in the
	245	* window. Caller function will decrease the counter.
	246	*/
	247	fl->fl_ops = &ceph_fl_lock_ops;
b3f8d68f YZ	248	atomic_inc(&ci->i_filelock_ref);
	249	}
	250	spin_unlock(&ci->i_ceph_lock);
	251	if (err < 0) {
	252	if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type)
	253	posix_lock_file(file, fl, NULL);
	254	return err;
89aa5930 YZ	255	}
89aa5930 YZ	256
40819f6f GF	257	if (F_RDLCK == fl->fl_type)
	258	lock_cmd = CEPH_LOCK_SHARED;
	259	else if (F_WRLCK == fl->fl_type)
	260	lock_cmd = CEPH_LOCK_EXCL;
	261	else
	262	lock_cmd = CEPH_LOCK_UNLOCK;
	263
89aa5930	264	err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl);
40819f6f	265	if (!err) {
b3f8d68f	266	if (op == CEPH_MDS_OP_SETFILELOCK) {
4c069a58	267	dout("mds locked, locking locally\n");
a5b10629	268	err = posix_lock_file(file, fl, NULL);
b3f8d68f	269	if (err) {
0c1f91f2 SW	270	/* undo! This should only happen if
	271	* the kernel detects local
	272	* deadlock. */
89aa5930	273	ceph_lock_message(CEPH_LOCK_FCNTL, op, inode,
a5b10629	274	CEPH_LOCK_UNLOCK, 0, fl);
4c069a58	275	dout("got %d on posix_lock_file, undid lock\n",
0c1f91f2	276	err);
a5b10629	277	}
40819f6f	278	}
40819f6f GF	279	}
	280	return err;
	281	}
	282
	283	int ceph_flock(struct file file, int cmd, struct file_lock fl)
	284	{
89aa5930	285	struct inode *inode = file_inode(file);
b3f8d68f YZ	286	struct ceph_inode_info *ci = ceph_inode(inode);
b3f8d68f YZ	287	int err = 0;
0e8e95d6	288	u8 wait = 0;
b3f8d68f	289	u8 lock_cmd;
40819f6f	290
eb70c0ce YZ	291	if (!(fl->fl_flags & FL_FLOCK))
	292	return -ENOLCK;
	293	/* No mandatory locks */
db4a63aa YZ	294	if (fl->fl_type & LOCK_MAND)
db4a63aa YZ	295	return -EOPNOTSUPP;
eb70c0ce	296
4c069a58	297	dout("ceph_flock, fl_file: %p\n", fl->fl_file);
40819f6f	298
b3f8d68f YZ	299	spin_lock(&ci->i_ceph_lock);
	300	if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) {
	301	err = -EIO;
	302	} else {
	303	/* see comment in ceph_lock */
	304	fl->fl_ops = &ceph_fl_lock_ops;
	305	atomic_inc(&ci->i_filelock_ref);
	306	}
	307	spin_unlock(&ci->i_ceph_lock);
	308	if (err < 0) {
	309	if (F_UNLCK == fl->fl_type)
	310	locks_lock_file_wait(file, fl);
	311	return err;
	312	}
89aa5930	313
0e8e95d6 YZ	314	if (IS_SETLKW(cmd))
	315	wait = 1;
	316
	317	if (F_RDLCK == fl->fl_type)
40819f6f	318	lock_cmd = CEPH_LOCK_SHARED;
0e8e95d6	319	else if (F_WRLCK == fl->fl_type)
40819f6f GF	320	lock_cmd = CEPH_LOCK_EXCL;
	321	else
	322	lock_cmd = CEPH_LOCK_UNLOCK;
40819f6f GF	323
40819f6f GF	324	err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
89aa5930	325	inode, lock_cmd, wait, fl);
40819f6f	326	if (!err) {
4f656367	327	err = locks_lock_file_wait(file, fl);
40819f6f GF	328	if (err) {
	329	ceph_lock_message(CEPH_LOCK_FLOCK,
	330	CEPH_MDS_OP_SETFILELOCK,
89aa5930	331	inode, CEPH_LOCK_UNLOCK, 0, fl);
4c069a58	332	dout("got %d on locks_lock_file_wait, undid lock\n", err);
40819f6f	333	}
40819f6f GF	334	}
	335	return err;
	336	}
	337
5263e31e JL	338	/*
	339	* Fills in the passed counter variables, so you can prepare pagelist metadata
	340	* before calling ceph_encode_locks.
40819f6f GF	341	*/
	342	void ceph_count_locks(struct inode inode, int fcntl_count, int *flock_count)
	343	{
e084c1bd	344	struct file_lock *lock;
5263e31e	345	struct file_lock_context *ctx;
40819f6f GF	346
	347	*fcntl_count = 0;
	348	*flock_count = 0;
	349
5263e31e JL	350	ctx = inode->i_flctx;
5263e31e JL	351	if (ctx) {
e084c1bd JL	352	spin_lock(&ctx->flc_lock);
	353	list_for_each_entry(lock, &ctx->flc_posix, fl_list)
	354	++(*fcntl_count);
	355	list_for_each_entry(lock, &ctx->flc_flock, fl_list)
	356	++(*flock_count);
	357	spin_unlock(&ctx->flc_lock);
40819f6f	358	}
4c069a58	359	dout("counted %d flock locks and %d fcntl locks\n",
40819f6f GF	360	flock_count, fcntl_count);
	361	}
	362
c6db8472 YZ	363	/*
	364	* Given a pointer to a lock, convert it to a ceph filelock
	365	*/
	366	static int lock_to_ceph_filelock(struct file_lock *lock,
	367	struct ceph_filelock *cephlock)
	368	{
	369	int err = 0;
	370	cephlock->start = cpu_to_le64(lock->fl_start);
	371	cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
	372	cephlock->client = cpu_to_le64(0);
	373	cephlock->pid = cpu_to_le64((u64)lock->fl_pid);
	374	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
	375
	376	switch (lock->fl_type) {
	377	case F_RDLCK:
	378	cephlock->type = CEPH_LOCK_SHARED;
	379	break;
	380	case F_WRLCK:
	381	cephlock->type = CEPH_LOCK_EXCL;
	382	break;
	383	case F_UNLCK:
	384	cephlock->type = CEPH_LOCK_UNLOCK;
	385	break;
	386	default:
4c069a58	387	dout("Have unknown lock type %d\n", lock->fl_type);
c6db8472 YZ	388	err = -EINVAL;
	389	}
	390
	391	return err;
	392	}
	393
40819f6f	394	/**
39be95e9	395	* Encode the flock and fcntl locks for the given inode into the ceph_filelock
1c8c601a	396	* array. Must be called with inode->i_lock already held.
39be95e9	397	* If we encounter more of a specific lock type than expected, return -ENOSPC.
40819f6f	398	*/
39be95e9 JS	399	int ceph_encode_locks_to_buffer(struct inode *inode,
	400	struct ceph_filelock *flocks,
	401	int num_fcntl_locks, int num_flock_locks)
40819f6f GF	402	{
40819f6f GF	403	struct file_lock *lock;
bd61e0a9	404	struct file_lock_context *ctx = inode->i_flctx;
40819f6f	405	int err = 0;
fca4451a GF	406	int seen_fcntl = 0;
fca4451a GF	407	int seen_flock = 0;
39be95e9	408	int l = 0;
40819f6f	409
4c069a58	410	dout("encoding %d flock and %d fcntl locks\n", num_flock_locks,
40819f6f	411	num_fcntl_locks);
39be95e9	412
bd61e0a9 JL	413	if (!ctx)
	414	return 0;
	415
6109c850	416	spin_lock(&ctx->flc_lock);
f6762cb2	417	list_for_each_entry(lock, &ctx->flc_posix, fl_list) {
bd61e0a9 JL	418	++seen_fcntl;
	419	if (seen_fcntl > num_fcntl_locks) {
	420	err = -ENOSPC;
	421	goto fail;
40819f6f	422	}
bd61e0a9 JL	423	err = lock_to_ceph_filelock(lock, &flocks[l]);
	424	if (err)
	425	goto fail;
	426	++l;
40819f6f	427	}
bd61e0a9 JL	428	list_for_each_entry(lock, &ctx->flc_flock, fl_list) {
	429	++seen_flock;
	430	if (seen_flock > num_flock_locks) {
	431	err = -ENOSPC;
	432	goto fail;
40819f6f	433	}
bd61e0a9 JL	434	err = lock_to_ceph_filelock(lock, &flocks[l]);
	435	if (err)
	436	goto fail;
	437	++l;
40819f6f GF	438	}
40819f6f GF	439	fail:
6109c850	440	spin_unlock(&ctx->flc_lock);
40819f6f GF	441	return err;
	442	}
	443
39be95e9 JS	444	/**
	445	* Copy the encoded flock and fcntl locks into the pagelist.
	446	* Format is: #fcntl locks, sequential fcntl locks, #flock locks,
	447	* sequential flock locks.
	448	* Returns zero on success.
	449	*/
	450	int ceph_locks_to_pagelist(struct ceph_filelock *flocks,
	451	struct ceph_pagelist *pagelist,
	452	int num_fcntl_locks, int num_flock_locks)
	453	{
	454	int err = 0;
	455	__le32 nlocks;
	456
	457	nlocks = cpu_to_le32(num_fcntl_locks);
	458	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
	459	if (err)
	460	goto out_fail;
	461
4deb14a2 YZ	462	if (num_fcntl_locks > 0) {
	463	err = ceph_pagelist_append(pagelist, flocks,
	464	num_fcntl_locks * sizeof(*flocks));
	465	if (err)
	466	goto out_fail;
	467	}
39be95e9 JS	468
	469	nlocks = cpu_to_le32(num_flock_locks);
	470	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
	471	if (err)
	472	goto out_fail;
	473
4deb14a2 YZ	474	if (num_flock_locks > 0) {
	475	err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks],
	476	num_flock_locks * sizeof(*flocks));
	477	}
39be95e9 JS	478	out_fail:
	479	return err;
	480	}