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Commit a75d30c7 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jeff Layton
Browse files

fs/locks: pass kernel struct flock to fcntl_getlk/setlk 



This will make it easier to implement a sane compat fcntl syscall.

[ jlayton: fix undeclared identifiers in 32-bit fcntl64 syscall handler ]

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
parent 80b79dd0

fs/fcntl.c

+22 −5
Original line number Diff line number Diff line
@@ -246,6 +246,8 @@ static int f_getowner_uids(struct file *filp, unsigned long arg) 
static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,

		struct file *filp)

{

	void __user *argp = (void __user *)arg;

	struct flock flock;

	long err = -EINVAL;



	switch (cmd) {
@@ -273,7 +275,11 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, 
	case F_OFD_GETLK:

#endif

	case F_GETLK:

		err = fcntl_getlk(filp, cmd, (struct flock __user *) arg);

		if (copy_from_user(&flock, argp, sizeof(flock)))

			return -EFAULT;

		err = fcntl_getlk(filp, cmd, &flock);

		if (!err && copy_to_user(argp, &flock, sizeof(flock)))

			return -EFAULT;

		break;

#if BITS_PER_LONG != 32

	/* 32-bit arches must use fcntl64() */
@@ -283,7 +289,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, 
		/* Fallthrough */

	case F_SETLK:

	case F_SETLKW:

		err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);

		if (copy_from_user(&flock, argp, sizeof(flock)))

			return -EFAULT;

		err = fcntl_setlk(fd, filp, cmd, &flock);

		break;

	case F_GETOWN:

		/*
@@ -383,7 +391,9 @@ SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg) 
SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,

		unsigned long, arg)

{	

	void __user *argp = (void __user *)arg;

	struct fd f = fdget_raw(fd);

	struct flock64 flock;

	long err = -EBADF;



	if (!f.file)
@@ -401,14 +411,21 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, 
	switch (cmd) {

	case F_GETLK64:

	case F_OFD_GETLK:

		err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg);

		err = -EFAULT;

		if (copy_from_user(&flock, argp, sizeof(flock)))

			break;

		err = fcntl_getlk64(f.file, cmd, &flock);

		if (!err && copy_to_user(argp, &flock, sizeof(flock)))

			err = -EFAULT;

		break;

	case F_SETLK64:

	case F_SETLKW64:

	case F_OFD_SETLK:

	case F_OFD_SETLKW:

		err = fcntl_setlk64(fd, f.file, cmd,

				(struct flock64 __user *) arg);

		err = -EFAULT;

		if (copy_from_user(&flock, argp, sizeof(flock)))

			break;

		err = fcntl_setlk64(fd, f.file, cmd, &flock);

		break;

	default:

		err = do_fcntl(fd, cmd, arg, f.file);

fs/locks.c

+22 −57
Original line number Diff line number Diff line
@@ -2084,26 +2084,22 @@ static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl) 
/* Report the first existing lock that would conflict with l.

 * This implements the F_GETLK command of fcntl().

 */

int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l)

int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock)

{

	struct file_lock file_lock;

	struct flock flock;

	int error;



	error = -EFAULT;

	if (copy_from_user(&flock, l, sizeof(flock)))

		goto out;

	error = -EINVAL;

	if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))

	if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK)

		goto out;



	error = flock_to_posix_lock(filp, &file_lock, &flock);

	error = flock_to_posix_lock(filp, &file_lock, flock);

	if (error)

		goto out;



	if (cmd == F_OFD_GETLK) {

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_GETLK;
@@ -2115,15 +2111,12 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l) 
	if (error)

		goto out;

 

	flock.l_type = file_lock.fl_type;

	flock->l_type = file_lock.fl_type;

	if (file_lock.fl_type != F_UNLCK) {

		error = posix_lock_to_flock(&flock, &file_lock);

		error = posix_lock_to_flock(flock, &file_lock);

		if (error)

			goto rel_priv;

	}

	error = -EFAULT;

	if (!copy_to_user(l, &flock, sizeof(flock)))

		error = 0;

rel_priv:

	locks_release_private(&file_lock);

out:
@@ -2216,26 +2209,16 @@ check_fmode_for_setlk(struct file_lock *fl) 
 * This implements both the F_SETLK and F_SETLKW commands of fcntl().

 */

int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,

		struct flock __user *l)

		struct flock *flock)

{

	struct file_lock *file_lock = locks_alloc_lock();

	struct flock flock;

	struct inode *inode;

	struct inode *inode = locks_inode(filp);

	struct file *f;

	int error;



	if (file_lock == NULL)

		return -ENOLCK;



	inode = locks_inode(filp);



	/*

	 * This might block, so we do it before checking the inode.

	 */

	error = -EFAULT;

	if (copy_from_user(&flock, l, sizeof(flock)))

		goto out;



	/* Don't allow mandatory locks on files that may be memory mapped

	 * and shared.

	 */
@@ -2244,7 +2227,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, 
		goto out;

	}



	error = flock_to_posix_lock(filp, file_lock, &flock);

	error = flock_to_posix_lock(filp, file_lock, flock);

	if (error)

		goto out;
@@ -2259,7 +2242,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, 
	switch (cmd) {

	case F_OFD_SETLK:

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_SETLK;
@@ -2268,7 +2251,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, 
		break;

	case F_OFD_SETLKW:

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_SETLKW;
@@ -2313,26 +2296,22 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd, 
/* Report the first existing lock that would conflict with l.

 * This implements the F_GETLK command of fcntl().

 */

int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l)

int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock)

{

	struct file_lock file_lock;

	struct flock64 flock;

	int error;



	error = -EFAULT;

	if (copy_from_user(&flock, l, sizeof(flock)))

		goto out;

	error = -EINVAL;

	if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))

	if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK)

		goto out;



	error = flock64_to_posix_lock(filp, &file_lock, &flock);

	error = flock64_to_posix_lock(filp, &file_lock, flock);

	if (error)

		goto out;



	if (cmd == F_OFD_GETLK) {

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_GETLK64;
@@ -2344,13 +2323,9 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) 
	if (error)

		goto out;



	flock.l_type = file_lock.fl_type;

	flock->l_type = file_lock.fl_type;

	if (file_lock.fl_type != F_UNLCK)

		posix_lock_to_flock64(&flock, &file_lock);



	error = -EFAULT;

	if (!copy_to_user(l, &flock, sizeof(flock)))

		error = 0;

		posix_lock_to_flock64(flock, &file_lock);



	locks_release_private(&file_lock);

out:
@@ -2361,26 +2336,16 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l) 
 * This implements both the F_SETLK and F_SETLKW commands of fcntl().

 */

int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,

		struct flock64 __user *l)

		struct flock64 *flock)

{

	struct file_lock *file_lock = locks_alloc_lock();

	struct flock64 flock;

	struct inode *inode;

	struct inode *inode = locks_inode(filp);

	struct file *f;

	int error;



	if (file_lock == NULL)

		return -ENOLCK;



	/*

	 * This might block, so we do it before checking the inode.

	 */

	error = -EFAULT;

	if (copy_from_user(&flock, l, sizeof(flock)))

		goto out;



	inode = locks_inode(filp);



	/* Don't allow mandatory locks on files that may be memory mapped

	 * and shared.

	 */
@@ -2389,7 +2354,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, 
		goto out;

	}



	error = flock64_to_posix_lock(filp, file_lock, &flock);

	error = flock64_to_posix_lock(filp, file_lock, flock);

	if (error)

		goto out;
@@ -2404,7 +2369,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, 
	switch (cmd) {

	case F_OFD_SETLK:

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_SETLK64;
@@ -2413,7 +2378,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd, 
		break;

	case F_OFD_SETLKW:

		error = -EINVAL;

		if (flock.l_pid != 0)

		if (flock->l_pid != 0)

			goto out;



		cmd = F_SETLKW64;

include/linux/fs.h

+4 −4
Original line number Diff line number Diff line
@@ -1038,14 +1038,14 @@ static inline struct inode *locks_inode(const struct file *f) 
}



#ifdef CONFIG_FILE_LOCKING

extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);

extern int fcntl_getlk(struct file *, unsigned int, struct flock *);

extern int fcntl_setlk(unsigned int, struct file *, unsigned int,

			struct flock __user *);

			struct flock *);



#if BITS_PER_LONG == 32

extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);

extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *);

extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,

			struct flock64 __user *);

			struct flock64 *);

#endif



extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);