From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Extract core functionality of fcntl_setlk() and fcntl_setlk64() into
separate functions, flock_set() and flock64_set() respective. These
functions can be also used when restarting a checkpointed application
and restoring its file-locks.
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Acked-by: Oren Laadan <orenl@xxxxxxxxxxxxxxx>
---
fs/locks.c | 76 +++++++++++++++++++++++++++++++--------------------
include/linux/fs.h | 4 +++
2 files changed, 50 insertions(+), 30 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index e30ad46..c3fc56d 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1807,14 +1807,13 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd,
return error;
}
-/* Apply the lock described by l to an open file descriptor.
+/* Apply the lock described by @flock to an open file descriptor.
* 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)
+int do_fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock *flock)
{
struct file_lock *file_lock = locks_alloc_lock();
- struct flock flock;
struct inode *inode;
struct file *f;
int error;
@@ -1822,13 +1821,6 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
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 = filp->f_path.dentry->d_inode;
/* Don't allow mandatory locks on files that may be memory mapped
@@ -1840,7 +1832,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
}
again:
- 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_SETLKW) {
@@ -1848,7 +1840,7 @@ again:
}
error = -EBADF;
- switch (flock.l_type) {
+ switch (flock->l_type) {
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
goto out;
@@ -1878,8 +1870,8 @@ again:
spin_lock(¤t->files->file_lock);
f = fcheck(fd);
spin_unlock(¤t->files->file_lock);
- if (!error && f != filp && flock.l_type != F_UNLCK) {
- flock.l_type = F_UNLCK;
+ if (!error && f != filp && flock->l_type != F_UNLCK) {
+ flock->l_type = F_UNLCK;
goto again;
}
@@ -1888,6 +1880,23 @@ out:
return error;
}
+int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock __user *l)
+{
+ int error;
+ struct flock flock;
+
+ /*
+ * This might block, so we do it before checking the inode
+ * in flock_set().
+ */
+ error = -EFAULT;
+ if (copy_from_user(&flock, l, sizeof(flock)))
+ return error;
+
+ return do_fcntl_setlk(fd, filp, cmd, &flock);
+}
+
#if BITS_PER_LONG == 32
/* Report the first existing lock that would conflict with l.
* This implements the F_GETLK command of fcntl().
@@ -1925,14 +1934,13 @@ out:
return error;
}
-/* Apply the lock described by l to an open file descriptor.
+/* Apply the lock described by @flock to an open file descriptor.
* 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)
+int do_fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock64 *flock)
{
struct file_lock *file_lock = locks_alloc_lock();
- struct flock64 flock;
struct inode *inode;
struct file *f;
int error;
@@ -1940,13 +1948,6 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
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 = filp->f_path.dentry->d_inode;
/* Don't allow mandatory locks on files that may be memory mapped
@@ -1958,7 +1959,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
}
again:
- 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_SETLKW64) {
@@ -1966,7 +1967,7 @@ again:
}
error = -EBADF;
- switch (flock.l_type) {
+ switch (flock->l_type) {
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
goto out;
@@ -1991,8 +1992,8 @@ again:
spin_lock(¤t->files->file_lock);
f = fcheck(fd);
spin_unlock(¤t->files->file_lock);
- if (!error && f != filp && flock.l_type != F_UNLCK) {
- flock.l_type = F_UNLCK;
+ if (!error && f != filp && flock->l_type != F_UNLCK) {
+ flock->l_type = F_UNLCK;
goto again;
}
@@ -2002,6 +2003,21 @@ out:
}
#endif /* BITS_PER_LONG == 32 */
+int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
+ struct flock64 __user *l)
+{
+ struct flock64 flock;
+
+ /*
+ * This might block, so we do it before checking the inode in
+ * flock64_set().
+ */
+ if (copy_from_user(&flock, l, sizeof(flock)))
+ return -EFAULT;
+
+ return do_fcntl_setlk64(fd, filp, cmd, &flock);
+}
+
/*
* This function is called when the file is being removed
* from the task's fd array. POSIX locks belonging to this task
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3d8bf75..7f38be1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1121,11 +1121,15 @@ extern void send_sigio(struct fown_struct *fown, int fd, int band);
extern int fcntl_getlk(struct file *, struct flock __user *);
extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
struct flock __user *);
+extern int do_fcntl_setlk(unsigned int, struct file *, unsigned int,
+ struct flock *);
#if BITS_PER_LONG == 32
extern int fcntl_getlk64(struct file *, struct flock64 __user *);
extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
struct flock64 __user *);
+extern int do_fcntl_set(unsigned int, struct file *, unsigned int,
+ struct flock64 *);
#endif
extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
--
1.7.1
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