fs/ceph/locks.c - maze/linux - Git at Google

 #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 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));
 }

 /**
  * Implement fcntl and flock locking functions.
  */
 static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
 			     int cmd, u8 wait, struct file_lock *fl)
 {
 	struct inode *inode = file_inode(file);
 	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;

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

 	/* 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;

 	if (lock_type == CEPH_LOCK_FCNTL)
 		owner = secure_addr(fl->fl_owner);
 	else
 		owner = secure_addr(fl->fl_file);

 	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
 	     "start: %llu, length: %llu, wait: %d, type: %d", (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;

 	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", (int)lock_type,
 	     (int)operation, (u64)fl->fl_pid, fl->fl_start,
 	     length, wait, fl->fl_type, err);
 	return err;
 }

 /**
  * 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)
 {
 	u8 lock_cmd;
 	int err;
 	u8 wait = 0;
 	u16 op = CEPH_MDS_OP_SETFILELOCK;

 	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", 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;

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

 	} else if (err == -ERESTARTSYS) {
 		dout("undoing lock\n");
 		ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
 				  CEPH_LOCK_UNLOCK, 0, fl);
 	}
 	return err;
 }

 int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
 {
 	u8 lock_cmd;
 	int err;
 	u8 wait = 0;

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

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

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

 /**
  * Must be called with lock_flocks() already held. 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;

 	*fcntl_count = 0;
 	*flock_count = 0;

 	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
 		if (lock->fl_flags & FL_POSIX)
 			++(*fcntl_count);
 		else if (lock->fl_flags & FL_FLOCK)
 			++(*flock_count);
 	}
 	dout("counted %d flock locks and %d fcntl locks",
 	     *flock_count, *fcntl_count);
 }

 /**
  * 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;
 	int err = 0;
 	int seen_fcntl = 0;
 	int seen_flock = 0;
 	int l = 0;

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

 	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
 		if (lock->fl_flags & FL_POSIX) {
 			++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;
 		}
 	}
 	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
 		if (lock->fl_flags & FL_FLOCK) {
 			++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:
 	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;

 	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;

 	err = ceph_pagelist_append(pagelist,
 				   &flocks[num_fcntl_locks],
 				   num_flock_locks * sizeof(*flocks));
 out_fail:
 	return err;
 }

 /*
  * Given a pointer to a lock, convert it to a ceph filelock
  */
 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);
 	if (lock->fl_flags & FL_POSIX)
 		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
 	else
 		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_file));

 	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", lock->fl_type);
 		err = -EINVAL;
 	}

 	return err;
 }
	#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 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));
	}

	/**
	* Implement fcntl and flock locking functions.
	*/
	static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
	int cmd, u8 wait, struct file_lock *fl)
	{
	struct inode *inode = file_inode(file);
	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;

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

	/* 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;

	if (lock_type == CEPH_LOCK_FCNTL)
	owner = secure_addr(fl->fl_owner);
	else
	owner = secure_addr(fl->fl_file);

	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
	"start: %llu, length: %llu, wait: %d, type: %d", (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;

	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", (int)lock_type,
	(int)operation, (u64)fl->fl_pid, fl->fl_start,
	length, wait, fl->fl_type, err);
	return err;
	}

	/**
	* 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)
	{
	u8 lock_cmd;
	int err;
	u8 wait = 0;
	u16 op = CEPH_MDS_OP_SETFILELOCK;

	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", 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;

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

	} else if (err == -ERESTARTSYS) {
	dout("undoing lock\n");
	ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
	CEPH_LOCK_UNLOCK, 0, fl);
	}
	return err;
	}

	int ceph_flock(struct file file, int cmd, struct file_lock fl)
	{
	u8 lock_cmd;
	int err;
	u8 wait = 0;

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

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

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

	/**
	* Must be called with lock_flocks() already held. 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;

	*fcntl_count = 0;
	*flock_count = 0;

	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
	if (lock->fl_flags & FL_POSIX)
	++(*fcntl_count);
	else if (lock->fl_flags & FL_FLOCK)
	++(*flock_count);
	}
	dout("counted %d flock locks and %d fcntl locks",
	flock_count, fcntl_count);
	}

	/**
	* 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;
	int err = 0;
	int seen_fcntl = 0;
	int seen_flock = 0;
	int l = 0;

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

	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
	if (lock->fl_flags & FL_POSIX) {
	++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;
	}
	}
	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
	if (lock->fl_flags & FL_FLOCK) {
	++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:
	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;

	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;

	err = ceph_pagelist_append(pagelist,
	&flocks[num_fcntl_locks],
	num_flock_locks * sizeof(*flocks));
	out_fail:
	return err;
	}

	/*
	* Given a pointer to a lock, convert it to a ceph filelock
	*/
	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);
	if (lock->fl_flags & FL_POSIX)
	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
	else
	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_file));

	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", lock->fl_type);
	err = -EINVAL;
	}

	return err;
	}