[PATCH] 2.5.3-pre3 fcntl_[gs]etlk* cleanup

Chris Wright (chris@wirex.com)
Mon, 21 Jan 2002 21:40:06 -0800


Hi,

The sys_fcntl() code does fget(fd) upon entry. Later during the
F_GETLK, F_SETLK, F_GETLK64 and F_SETLK64 code paths, the fd is looked
up again, rather than using the filp that is already known. AFAICT this
is not necessary. The patch below addresses this.

- fcntl_getlk, fcntl_setlk, fcntl_setlk64, and fcntl_getlk64 now take filp
- collapse F_SETLK64 and F_SETLKW64 cases to one fall through case.
- removed unused -EINVAL assignment in fcntl_setlk and fcntl_setlk64

I have compiled, but not booted this patch.

Comments?

thanks,
-chris

diff -X /home/chris/dontdiff -Naur linux-2.5.3-pre3/fs/fcntl.c linux-2.5.3-pre3-setlk/fs/fcntl.c
--- linux-2.5.3-pre3/fs/fcntl.c Mon Jan 21 18:28:32 2002
+++ linux-2.5.3-pre3-setlk/fs/fcntl.c Mon Jan 21 20:28:33 2002
@@ -296,11 +296,11 @@
unlock_kernel();
break;
case F_GETLK:
- err = fcntl_getlk(fd, (struct flock *) arg);
+ err = fcntl_getlk(filp, (struct flock *) arg);
break;
case F_SETLK:
case F_SETLKW:
- err = fcntl_setlk(fd, cmd, (struct flock *) arg);
+ err = fcntl_setlk(filp, cmd, (struct flock *) arg);
break;
case F_GETOWN:
/*
@@ -382,13 +382,11 @@

switch (cmd) {
case F_GETLK64:
- err = fcntl_getlk64(fd, (struct flock64 *) arg);
+ err = fcntl_getlk64(filp, (struct flock64 *) arg);
break;
case F_SETLK64:
- err = fcntl_setlk64(fd, cmd, (struct flock64 *) arg);
- break;
case F_SETLKW64:
- err = fcntl_setlk64(fd, cmd, (struct flock64 *) arg);
+ err = fcntl_setlk64(filp, cmd, (struct flock64 *) arg);
break;
default:
err = do_fcntl(fd, cmd, arg, filp);
diff -X /home/chris/dontdiff -Naur linux-2.5.3-pre3/fs/locks.c linux-2.5.3-pre3-setlk/fs/locks.c
--- linux-2.5.3-pre3/fs/locks.c Mon Jan 7 12:55:16 2002
+++ linux-2.5.3-pre3-setlk/fs/locks.c Mon Jan 21 21:00:06 2002
@@ -1352,9 +1352,8 @@
/* Report the first existing lock that would conflict with l.
* This implements the F_GETLK command of fcntl().
*/
-int fcntl_getlk(unsigned int fd, struct flock *l)
+int fcntl_getlk(struct file *filp, struct flock *l)
{
- struct file *filp;
struct file_lock *fl, file_lock;
struct flock flock;
int error;
@@ -1366,19 +1365,14 @@
if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))
goto out;

- error = -EBADF;
- filp = fget(fd);
- if (!filp)
- goto out;
-
error = flock_to_posix_lock(filp, &file_lock, &flock);
if (error)
- goto out_putf;
+ goto out;

if (filp->f_op && filp->f_op->lock) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
if (error < 0)
- goto out_putf;
+ goto out;
else if (error == LOCK_USE_CLNT)
/* Bypass for NFS with no locking - 2.0.36 compat */
fl = posix_test_lock(filp, &file_lock);
@@ -1398,10 +1392,10 @@
*/
error = -EOVERFLOW;
if (fl->fl_start > OFFT_OFFSET_MAX)
- goto out_putf;
+ goto out;
if ((fl->fl_end != OFFSET_MAX)
&& (fl->fl_end > OFFT_OFFSET_MAX))
- goto out_putf;
+ goto out;
#endif
flock.l_start = fl->fl_start;
flock.l_len = fl->fl_end == OFFSET_MAX ? 0 :
@@ -1413,8 +1407,6 @@
if (!copy_to_user(l, &flock, sizeof(flock)))
error = 0;

-out_putf:
- fput(filp);
out:
return error;
}
@@ -1422,12 +1414,11 @@
/* Apply the lock described by l to an open file descriptor.
* This implements both the F_SETLK and F_SETLKW commands of fcntl().
*/
-int fcntl_setlk(unsigned int fd, unsigned int cmd, struct flock *l)
+int fcntl_setlk(struct file *filp, unsigned int cmd, struct flock *l)
{
- struct file *filp;
struct file_lock *file_lock = locks_alloc_lock(0);
struct flock flock;
- struct inode *inode;
+ struct inode *inode = filp->f_dentry->d_inode;
int error;

if (file_lock == NULL)
@@ -1440,17 +1431,6 @@
if (copy_from_user(&flock, l, sizeof(flock)))
goto out;

- /* Get arguments and validate them ...
- */
-
- error = -EBADF;
- filp = fget(fd);
- if (!filp)
- goto out;
-
- error = -EINVAL;
- inode = filp->f_dentry->d_inode;
-
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
*/
@@ -1460,23 +1440,25 @@

if (mapping->i_mmap_shared != NULL) {
error = -EAGAIN;
- goto out_putf;
+ goto out;
}
}

+ /* Get arguments and validate them ...
+ */
error = flock_to_posix_lock(filp, file_lock, &flock);
if (error)
- goto out_putf;
+ goto out;

error = -EBADF;
switch (flock.l_type) {
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
- goto out_putf;
+ goto out;
break;
case F_WRLCK:
if (!(filp->f_mode & FMODE_WRITE))
- goto out_putf;
+ goto out;
break;
case F_UNLCK:
break;
@@ -1494,23 +1476,21 @@
}
}
if (!(filp->f_mode & 3))
- goto out_putf;
+ goto out;
break;
#endif
default:
error = -EINVAL;
- goto out_putf;
+ goto out;
}

if (filp->f_op && filp->f_op->lock != NULL) {
error = filp->f_op->lock(filp, cmd, file_lock);
if (error < 0)
- goto out_putf;
+ goto out;
}
error = posix_lock_file(filp, file_lock, cmd == F_SETLKW);

-out_putf:
- fput(filp);
out:
locks_free_lock(file_lock);
return error;
@@ -1520,9 +1500,8 @@
/* Report the first existing lock that would conflict with l.
* This implements the F_GETLK command of fcntl().
*/
-int fcntl_getlk64(unsigned int fd, struct flock64 *l)
+int fcntl_getlk64(struct file *filp, struct flock64 *l)
{
- struct file *filp;
struct file_lock *fl, file_lock;
struct flock64 flock;
int error;
@@ -1534,19 +1513,15 @@
if ((flock.l_type != F_RDLCK) && (flock.l_type != F_WRLCK))
goto out;

- error = -EBADF;
- filp = fget(fd);
- if (!filp)
- goto out;

error = flock64_to_posix_lock(filp, &file_lock, &flock);
if (error)
- goto out_putf;
+ goto out;

if (filp->f_op && filp->f_op->lock) {
error = filp->f_op->lock(filp, F_GETLK, &file_lock);
if (error < 0)
- goto out_putf;
+ goto out;
else if (error == LOCK_USE_CLNT)
/* Bypass for NFS with no locking - 2.0.36 compat */
fl = posix_test_lock(filp, &file_lock);
@@ -1569,8 +1544,6 @@
if (!copy_to_user(l, &flock, sizeof(flock)))
error = 0;

-out_putf:
- fput(filp);
out:
return error;
}
@@ -1578,12 +1551,11 @@
/* Apply the lock described by l to an open file descriptor.
* This implements both the F_SETLK and F_SETLKW commands of fcntl().
*/
-int fcntl_setlk64(unsigned int fd, unsigned int cmd, struct flock64 *l)
+int fcntl_setlk64(struct file *filp, unsigned int cmd, struct flock64 *l)
{
- struct file *filp;
struct file_lock *file_lock = locks_alloc_lock(0);
struct flock64 flock;
- struct inode *inode;
+ struct inode *inode = filp->f_dentry->d_inode;
int error;

if (file_lock == NULL)
@@ -1596,16 +1568,6 @@
if (copy_from_user(&flock, l, sizeof(flock)))
goto out;

- /* Get arguments and validate them ...
- */
-
- error = -EBADF;
- filp = fget(fd);
- if (!filp)
- goto out;
-
- error = -EINVAL;
- inode = filp->f_dentry->d_inode;

/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
@@ -1616,23 +1578,25 @@

if (mapping->i_mmap_shared != NULL) {
error = -EAGAIN;
- goto out_putf;
+ goto out;
}
}

+ /* Get arguments and validate them ...
+ */
error = flock64_to_posix_lock(filp, file_lock, &flock);
if (error)
- goto out_putf;
+ goto out;

error = -EBADF;
switch (flock.l_type) {
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
- goto out_putf;
+ goto out;
break;
case F_WRLCK:
if (!(filp->f_mode & FMODE_WRITE))
- goto out_putf;
+ goto out;
break;
case F_UNLCK:
break;
@@ -1640,18 +1604,16 @@
case F_EXLCK:
default:
error = -EINVAL;
- goto out_putf;
+ goto out;
}

if (filp->f_op && filp->f_op->lock != NULL) {
error = filp->f_op->lock(filp, cmd, file_lock);
if (error < 0)
- goto out_putf;
+ goto out;
}
error = posix_lock_file(filp, file_lock, cmd == F_SETLKW64);

-out_putf:
- fput(filp);
out:
locks_free_lock(file_lock);
return error;
diff -X /home/chris/dontdiff -Naur linux-2.5.3-pre3/include/linux/fs.h linux-2.5.3-pre3-setlk/include/linux/fs.h
--- linux-2.5.3-pre3/include/linux/fs.h Mon Jan 21 18:28:33 2002
+++ linux-2.5.3-pre3-setlk/include/linux/fs.h Mon Jan 21 20:40:14 2002
@@ -587,11 +587,11 @@

#include <linux/fcntl.h>

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

-extern int fcntl_getlk64(unsigned int, struct flock64 *);
-extern int fcntl_setlk64(unsigned int, unsigned int, struct flock64 *);
+extern int fcntl_getlk64(struct file *, struct flock64 *);
+extern int fcntl_setlk64(struct file *, unsigned int, struct flock64 *);

/* fs/locks.c */
extern void locks_init_lock(struct file_lock *);
-
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